Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons http://www.archive.org/details/manualofdiseases19071gowe A MANUAL V9 DISEASES OF THE NERVOUS SYSTEM BY THE SAME AUTHOR A MartiSial of Diseases of the Nervous System. Vol. II. — Brain and Cranial Nerves: General and Func- tional Diseases of the Nervous System. Second Edi- tion. Octavo. With 182 Engravings. Cloth, $4.00 ; Sheep, $5.00. Clinical Lectures on Diseases of the Nervous System. 8vo. Cloth, $2.00. Syphilis and the Nervous System; being a Revised Reprint of the Lettsomian Lectures for 1890. 8vo. Cloth, $1.00. Epilepsy and other Chronic Convulsive Diseases. Second Edition. 8vo. Cloth, $3.00. A Manual and Atlas of Medical Ophthalmoscopy. Third Edition. Edited hy De. GpwEES with the assistance of Maecus Gunn, M.B., F.E.c.s. With Coloured Plates and Woodcuts. 8vo. Cloth, $4.00. These prices are net. Note. — The illustrations of which the source is not stated are original, and part of the copyright of the hook. A MANUAL DISEASES OF THE NERVOUS SYSTEM SIR W. R. GOWERS, M.D., F.R.C.P., F.R.S. CONSULTING PHYSICIAN TO UNIVERSITY COLLEGE HOSPITAL ; PHYSICIAN TO THE NATIONAL HOSPITAL FOR THE PARALYSED AND EPILEPTIC, QUEEN SQUARE XTbtrt) lEbition REVISED AND ENLARGED EDITED BY SIR W. R. GOWERS AND JAMES TAYLOR, M.A., M.D., F.R.C.P. SENIOR ASSISTANT PHYSICIAN TO THE NATIONAL HOSPITAL FOR THE PARALYSED AND EPILEPTIC, QUEEN SQUARE ; PHYSICIAN TO THE NORTH-EASTERN HOSPITAL FOR CHIL- DREN AND TO THE NATIONAL ORTHOPEDIC HOSPITAL VOLUME I DISEASES OF THE NERVES AND SPINAL CORD WITH ONE HUNDRED AND NINETY-TWO ILLUSTRATIONS PHILADELPHIA P. BLAKISTON'S SON & CO. 1012 WALNUT STREET 1907 PREI^ACE TO THE EIRST EDITION. This volume contains the first part of an attempt to give an account of diseases of the nervous system, sufl&ciently concise to be within the compass of the time-pressed student or busy practitioner, and yet adequate in its outline of a subject which has become wide and deep beyond any other part of medicine. Success in both aims can scarcely be more than approximate. Most of the illustrations are printed from blocks prepared from original drawings by phototype processes, and I am in- debted to Messrs. A. and W. Dawson, of the Typographic Etching Company (by whom most of the work has been done) for the care they have taken in the reproduction. The casual reader may perhaps miss subsidiary letters in the illustrations of the lesions of the spinal cord. The omission of these is intentional. A knowledge of the structural topogi-aphy of the cord is the first requisite in the study of its morbid anatomy, and when this knowledge is gained, the figures will be understood without difficulty. Familiarity with unlettered illustrations facilitates the comprehension of sections of tha spinal cord. Queen Anne Stbebt, Lokdoi August, 1886. PREEAOE TO THE THIED EDITION. In tlie present edition every chapter has been subjected to careful revision, and numerous additions have been made em- bodying the results of personal experience and the more important facts ascertained by others. We are indebted to Dr. Bertram Abrahams for assistance in the revision of the section on the Anatomy and Functions of the Spinal Cord, and to Dr. F. E. Batten for the appendix on the Muscle-spindles. W. R. GOWERS. JAMES TAYLOR. ■January. 1890. CONTENTS. PAOB INTRODUCTION . . . . . . 1 Classification of Diseases of the Nervous System, 2 PAET I.— GENERAL SYMPTOMATOLOGY . Symptoms and theie Investigation • . Motor Symptoms • . . , Inco-ordination of Movement, 10 Sensory Symptoms .... Tactile Sensibility, 13; Sensibility to Pain, 15; Sensibility to Temperature, 15 ; Muscular Sensibility, 16 Reflex Action .... Cutaneous Eeflex Action, 19; Muscle Reflex Action- " Ten don -reflexes," 20; Paradoxical Muscular Contrac. tion, 27 Changes in Nutrition . . . • Electrical Irritability .... MtrSCLES: THEIR ACTION AND PaEALTSIS Muscles moving the Upper Limb, 34 ; the Lower Limb, 45 Thb General Constitxjtion op the Nervous System . PART IL— DISEASES OP THE NERVES General Pathology .... Structure of Nerves, 62 ; Physiology of Nerves, 63 ; Lesions of Nerves, Secondaiy Degeneration, 65 Symptoms of Neevb-injuey and Degeneeation Electrical Changes, 71; Sensory Symptoms, 78; Reflex Action 79 ; Vaso- motor and Trophic Disturbance, 79 Injtteies of Neeves . . . . Compression, 80 Inflammation of Neeves : Neiteitis . . Causes, 82 ; Pathological Anatomy, 83 ; Symptoms, 85 ; Dia^ gnosis, 87 ; Prognosis, 87 ; Treatment, 88 7 7 13 19 27 29 33 63 62 62 71 80 82 X CONTENTS. Spinal Meningitis (continued) — pagb Internal Meningitis . • • • . 313 Acute Internal Meningitis .... 313 Causes, 313 ; Pathological Anatomy, 315 ; Symptoms, 317 ; Diagnosis, 319 ; Prognosis, 321 ; Treatment, 321 Chronic Internal Meningitis .... 322 Causes, 323 ; Pathological Anatomy, 324 ; Symptoms, 328; Diagnosis, 330; Prognosis, 332 ; Treatment, 333 H^MOREHAGE INTO SpiNAL MeMBEANES : SpINAL MENINGEAL HjiMOEEHAGE : H^MATOEEHACHIS . . . 334 Causes, 334; Pathological Anatomy, 335; Symptoms, 336; Diagnosis, 337 ; Prognosis, 338 ; Ti-eatment, 338 DISEASES OF THE CORD . . , . .339 Anemia and Hypee^mia . . • • • 339 Anaemia, 340 ; Hypersemia, 342 Inflammation— Myelitis . ■ . . • , 343 Acute Myelitis ..... 344 Etiology, 344 ; Pathological Anatomy, 348 ; Symptoms, 358 ; Varieties, 365; Pathology, 367; Diagnosis, 368; Prog- nosis, 372 ; Treatment. 373 Abscess ...••• 377 Embolism ...... 377 Cheonic Myelitis ..... 378 Etiology, 379 ; Pathological Anatomy, 382 ; Symptoms, 386 ; Diagnosis, 387 ; Prognosis, 388 ; Treatment, 389 COMPEESSION ...... 390 Causes, 390 ; Pathological Anatomy, 390 ; Symptoms, 393 ; Diagnosis, 394 ; Prognosis and Treatment, 395 Anteeioe Polio-myelitis: Ateophic Spinal Paealysis • 395- Acute Atrophic Paralysis [Infantile Palsy) . . 396- Etiology, 397 ; Symptoms, 399 ; Pathology, 409 ; Diagnosis, 416 ; Prognosis, 418 ; Treatment, 419 Subacute and Chronic Atrophic Spinal Paralysis . . 424 Acute Ascending Paealysis .... 427 Causes and Symptoms, 427, 428 ; Pathology, 430 ; Diagnosis and Prognosis, 431 ; Treatment, 432 Paealysis feom Lessened Atmosphekic Peessuee — Dxvees' Paralysis — 'Caisson Disease .... 433 Symptoms, 483 ; Pathology, 434 H^EMORRHAGE INTO SpINAL CoRD — U^MATOMYELIA . . 437 Etiology, 437 ; Patholo.sical Anatomy, 43.S ; Symptoms, 439 ; Diiignosis, 441 ; Prognosis and Treatment, 441 CONTENTS. XI FAGB DEGENERATIONS OF THE CORD . • • -.442 LocoMOTOE Ataxy — Tabes Dorsalis . . . 444 History, 444; Causes, 445; Symptoms, 448; Motor, 449; Sensory, 450; Eeflex, 454; Eye, 455; Sphincters, 458; Vaso-motor and Trophic, 459; Visceral, 461 ; Course and Termination, 463 ; Complications, 465 ; Pathological Ana- tomy, 467 ; Pathology, 474 ; Diagnosis, 480 ; Prognosis, 483 ; Treatment, 484 Pbimaey Spastic Paraplegia — Primary Lateral Sclerosis . 48& General Pathology, 489; Causes, 492; Symptoms, 493 ; Patho- logical Anatomy, 497 ; Diagnosis, 500; Prognosis and Treat- ment, 502 ; Family form, 503 Ataxic Paraplegia . . . . • 503 Causes, 504; Symptoms, 505; Pathological Anatomy, 507; Pathology, 508; Diagnosis, 510; Prognosis and Treatment, 511 Sclerosis of Coed from Toxic Blood-states • > 511 Pellagra . . . • • ^ 511 Causes and Symptoms . . v. . 512 Sclerosis from other Toxic Blood-states . . . 513^ Symptoms, 514; Morbid Anatomy, 515; Pathology, 516; Diagnosis, Prognosis, Treatment, 618 Hereditary Ataxy — Friedreich's Disease . . . 519- Symptoms, 520 ; Pathological Anatomy, 525 ; Pathology, 628; Diagnosis, 529 ; Prognosis and Treatment, 530 Simple Senile Paraplegia .... 530 Chronic Spinal Musculak Atrophy: Peogeessivb Muscular Atrophy ...... 531 Causes, 533; Symptoms, 534; Varieties and Complications, 542, 543 ; Course, 543 ; Pathological Anatomy, 545 ; Path- ology, 551 ; Diagnosis, 555 ; Prognosis, 556 ; Treatment, 557 Arthritic Muscular Atrophy . . . , 559 Pathology, 560; Diagnosis and Prognosis, 560; Treatment, 562 Muscular Atrophy from Over-use • . 663 The Muscular Dystrophies .... 563 Pseudo-hypertrophio Muscular Paralysis : Jjipomatous Mus- cular Atrophy ..... 567 Etiology, 568; Symptoms, 569; Varieties and Complica- tions, 576 ; Pathological Anatomy, 577 ; Pathology, 579 ; Diagnosis, 581 ; Prognosis, 582 ; Treatment, 582 Simple Idiopathic Muscular Atrophy . . . 583 Causes, 585 ; Symptoms, 586 ; Pathological Anatomy, 590 ; Diagnosis, 591 ; Prognosis and Treatment, 592 Peroneal type of Family Amyotrophy . . . 593 Family Form of Muscular Atrophy in Children with Spinal Cord Lesion . . . . • 597 Muscular Hyppvlrophy • • > . 599 Xll CONTENTS. FAOB Thomsen's Disease: Myotonia congenita • • . 601 Pathology, 604 ; Treatment, 605 ; Congenital Paramyotone« 605 ; Ataxic Paramyotone, 606 TUMOUES OP THE CoED . . . . . 607 Etiology, 607 ; Pathological Anatomy, 608 ; Symptoms, 616 ; Diagnosis, 622 ; Prognosis, 625 ; Treatment, 626 Cavities and Fissttees in the Coed: Steingomtelia, Htdeo- MTELiA, Htdeoeehachis inteena . . . 628 Etiological Pathology, 629; Symptoms, 639; Diagnosis, 643; Prognosis and Treatment, 645 Analgic fanaeitium: Moetak's Disease • • • 645 Spina bifida . . , , . • 647 Teattmatic Lesions of the Coed .... 652 Causes, 652; Pathology, 658; Symptoms, 654; Diagnosii, 661 ; Prognosis, 662 ; Treatment, 663 Functional xsd Nuteitional Diseases of the Coed . 664 Functional Diseases, 664 ; Nutritional Diseases, 668 APPENDIX ON MUSCLE-SPINDLES • . 671 INDEX . . . .676 LIST OP ILLUSTRATIONS. Fia. pxoB 1, 2, The Knee-jerk, mode of obtaining it • • •21 3. The Foot-clonus, mode of obtaining it • • •22 4. Tracing of the Foot-clonus . . • • #23 6. 6. Paralysis and Wasting of the Trapezius . • • 34 7. Paralysis and Wasting of the Deltoid and TmpeziuB • #35 8. Paralysis of the Serratus Magnus . . • .36 9. Paralysis of the Deltoid . , • • .36 10. Motor Points for the Arm, inner side • • • • 38 11. „ „ outer side . . • • 39 12. Paralysis of the Long Kadial Extensor of the Wvist • #40 13. Contraction of the Palmar Fascia . . • ,41 14t Paralysis of part of the Flexor Digitorum Sublimis • .41 16 — 18. Pai'alysis of the Interossei . . • 42, 43 19, 20. Claw-like Hand from Nerve-injury . • ,43 21. The Thumb, normal position of . • . ,44 22. Ape-like Position of the Thumb from Paralysis of its Muscles . 44 23. „ „ „ in greater degree .... 24. Paralysis of the Abductor Brevis and Opponens PoUicis 26. Motor Points on the Front of the Thigh 26. „ of Leg, outer side . . 27. „ on the Back of Thigh and Leg: • 28. Talipes Calcaneus .... 29. „ Equinus at rest and in Flexion of the Ankle 30. „ „ extreme 31. Paralysis of the Interossei and Muscles of the Great Toe 32. Diagram of Structure of Nerve- fibres . 33. Degeneration and Regeneration of Nerve-fibres . 34. Degeneration of Fibres of Cutaneous Nerves 35. Chart of Degenerative Reaction in transient Nerve-injiiiy 36. „ „ in permanent degeneration 37. Tracings of Muscular Contractions in Nerve Degeneration 38—43. Chart of Electrical Reactions in Neuritis • 44. Neuritis, Microscopical Changes . • 45. Plexiform Neuroma from the Or,bit , • 46. Neuromata in the Skin of Abdomen , • 47. „ Multiple of the Arm • r 75- 44 45 46 48 49 60 51 51 61 62 66 66 71 73 74 -77 83 91 92 92 PAGE Bodies and to the 182 194 195 200 201 202 20:J SlY LIST OF ILLUSTEATIOKS. Fig. 4,8. Neuromata, Multiple, of the Arm, Nerves dissected out . -.92 49. Neuroma of the Posterior Tibial Nerve , , .92 50. „ of Popliteal Nerve . . . . . 92 51. Area of Anaesthesia after Division of 8th Cervical and 1st Dorsal Boots . . . .100 52. „ „ from Disease of the Circumflex Nerve . 104 ^3. Wrist-drop from Paralysis of Musculo-spiral Nerve . . 106 54. Carpal Prominence from Paralysis of the Extensors of the Fingers . 106 55. Palsy of Deltoid, Supra-spinatus, and Infra-spinatus . . 112 66, 57. Contracture of Hand from a growth in the Cervical Spine . 112 58. Multiple Alcoholic Neuritis, Palsy of Extremities . . 153 59, 60. „ „ Microscopical Appearances in the Nerves 165, 166 ■61. Apparatus for treatment of Drop-foot . 62. Leprosy, Areas of Anajsthesia 63. „ Changes in the Nerves 64. The Eelation of the Vertebral Spines to their Origin of the Nerve-roots . . ' 65. Diagram of a Section of the Spinal Cord 66. Diagrams of the Cord at different levels 67. Nerve-cell from the Spinal Cord of Man 68. Nerve-cells sending a Process into the Anterior Root . « 203 69. Junction of a Divided Nerve-fibre with separate Nerve-cells • 203 70. The Groups of Nerve-cells in the Anterior Cornu , • 205 71. The Elements of the White Substance at various levels • • 208 72. Ascending and Descending Degenerations . • . 210 73. Descending Degeneration in Hemiplegia • „' 211 74. Diagram of an Element of the Motor Path . • . 213 75. Degeneration o£ the Antero-lateral Ascending Tract . . 214 76. „ „ „ „ and the Postero- median Column ...... 214 77. Degeneration after Injury to the Cauda Equina . « 214 78. „ a Lesion in Cervical Region . • • 216 79. „ Injury to the lowest part of the Cord • . 216 80. Posterior Cornu and Column at the last Dorsal Segment • • 218 SI. Cervical Section ; Ascending Degenerations . • • 221 82. Central Canal in Normal Cords . . . ^ 224 83. The Arteries of the Spinal Cord . . • .227 84. Spinal Cord contused by Gunshot Injury . • •■ 236 85. Tracings of the Action of the Sphincter Ani , • . 246 86. Plan of the Centre for Micturition . . • . 247 87. 88. Cutaneous areas corresponding to Sensory Roots • 250, 251 89. Fracture of the First Lumbar Vertebra . • • 283 90. Spinal Cord damaged by Fracture . » • • 284 91. Fracture of the Fifth Dorsal Vertebra. . . -284 92. Caries of the Spine ..».,■■ 288 93. External Pachymeningitis in Caries of the Spine . 311 D4. Purulent Meningitis ; Section of Spinal Cord and Membranes 316 95. „ ,, Infiltration of Arachnoid . . '^< ' 96. Chronic Alcoholic Meningitis , , » 325 97. Myelitis ; Inflammatory Products . . • , 349 98. Subacute Myelitis, Lumbar Region , . • . 350 LIST OP ILLUSTRATIONS. XV Fig. i'AGE 99. Subacute Myelitis, more liigVily magnified • • • 350 100. Subacute Disseminated Myelitis; Spider Cells . . . 351 101, 102. Acute Transverse Myelitis ; Dilatation of the Central Canal 362, 354 357 357 361 381 381 383 385 391 392 406 406 4^7 4D7 410 411 412 456 456 459 460 461 461 467 468 103. Ascending Myelitis from Fracture of Spine . . 104. „ „ more highly magnified • • 105. Feet in Myelitis of Lumbar Enlargement • • 106. Chronic Myelitis ..... 107. Chronic Sclerotic Myelitis . . . . 108. „ „ more highly magnified . 109. Chronic Meningo-myelitis ; Syringomyelia . . 110. Compression of the Spinal Cord and Pressure-myelitis . 111. Pressure-myelitis, more highly magnified . • 112. Atrophic Spinal Paralysis ; Talipes Valgus and Varus . 113. „ „ Talipes Calcaneus . . 114. „ „ Left Arm . • 115. „ „ affecting the Hand . • 116. „ „ Microscopic Changes • 117. n f> fourteenth day . . 118. „ „ Spinal Cord in Lumbar Eegioa 119. Unilateral Tabetic Ptosis .... 120. Double Tabetic Ptosis .... 121. Perforating Ulcer of the Foot in Tabes . . 122 Locomotor Ataxy ; Swelling of Elbow . • 123. „ „ Retroflexion of Knee-joints . • 124. Tabetic Foot ..... 125. Locomotor Ataxy ; Sections of Spinal Cord . . 126. „ „ Section of Cervical Region . . 127. 128. „ „ complete Sclerosis of Posterior Columns 469, 470 129 „ „ Chronic Meningitis . . . 472 130. Osseous Lesions in Tabes ..... 473 131. Congenital Spastic Paralysis (Cerebral) . . • 496 132. ,, „ „ Cross-legged Progression • 496 133. Sclerosis of the Pyramidal Tracts .... 497 134. „ „ in Muscular Atrophy . . 498 135. Ataxic Paraplegia; Combined Lateral and Posterior Sclerosis • 608 136. Cord in Pellagra ...... 612 137. Sclerosis of Cord in Anaemia .... 615 138. Lateral Curvature in Hereditary Ataxy ... 522 139. Deformity of Foot in „ ... 523 140. Hereditary Ataxy ; Sections of Lumbar Cord . • . 525 141. „ „ Sections of Spinal Cord . . . 523 142. „ „ „ Cervical, Doisal, and Lumbar Regions 526 143. „ „ Degeneration of Posterior Nerve-roots . 527 144. Progressive Muscular Atrophy : Wasting of Back and Arms . 636 145. „ „ Wasting of the Back Muscles . 636 146. „ „ Weakness of the Neck . . 637 147—150. „ „ Fibres of Wasted Muscles . 546 151. Normal Anterior Cornu ..... 647 152. Progressive Muscular Atrophy ; Anterior Cornu . , 547 153. „ „ Degeneration of the Anterior Cornu and Pyramidal Tracts . 648 XVI LIST OF ILLUSTRATIONS. Fig. pagb 154. Progressive Muscular Atrophy ; Degeneration in Medulla and Cord 549 155, 156. Pseudo-hypertrophic Paralysis .... 570 157. „ „ Partial Enlargement of Eectus . 570 158, 159. If M Absence of Latissimus Dorsi ; Enlargement of Infraspinatus 571 160, 161. „ M Mode of rising . . 572 162. „ „ Late Stage ; Muscular Contrac- tion and Wasting . . 574 163. Pseudo-hypertrophic Paralysis ; Weakness of the Spinal Muscles . 575 164. „ „ Enlargement of the Vasti . 576 1(J5, 166. „ „ Muscular Alterations . 677, 578 167. Section of a Myolipoma attached to the Spinal Cord • . 680 168. Simple Idiopathic Muscular Atrophy. . . • 684 169 — 171. Idiopathic Muscular Atrophy affecting the Face . . 589 172. „ „ showing Lordosis . . • 690 173. Advanced Muscular Atrophy, probably of the " Peroneal Type" . 595 174. Myolipoma of the Spinal Cord .... 608 175. Tumour growing from the Dura Mater . . . 611 176. Sarcoma between the Arachnoid and Pia Mater . • . 611 177. 178. Tumour growing from the Dura Mater . • 611, 612 . 612 . 612 . 613 . 614 . 630 .681 with extensive Gliomatosis . . • 632 179. „ of the Cauda Equina 180. Neuromata of the Cauda Equina 181.. Central Tumour of Spinal Cord 182. Syphiloma in the Spinal Cord 183. Central Canal in Normal Cords 184. Syringomyelia from a Child 185. 186. 187. 188 189, with Tumours of the Pons and Cauda Equina • 633 aflsociated with Multiple Growths . • 635 with Hsemorrhiii^e into the Cavity . • 636 with Irregular Cavities in the Spinal Cord • 639 190. Spina Bifida ; sections of Spinal Cord . » • 649 191. Diagram of Muscle-spindle . . • • 672 192. Transverse Sections of Normal Muscle-spindl* » • 673 DISEASES OF THE NERVOUS SYSTEM. INTRODUCTION. A CLASSIFICATION of Diseases of tlie Nervous System, at once scientific, exact, and conrenient for systematic description, is not at present possible. If we attempt to classify the diseases according to either seat or nature, we are met at once by difficulties wMcli prevent any complete arrangement. These difficulties arise from the fact that many diseases affect more than one part of the nervous system, that the precise seat of other maladies is unkaown, and that we are still ignorant of the nature of a considerable number of diseases. A rough division is often made into two broad classes of "organic" and "functional" disease. The first class, that of "organic diseases," comprehends those in which there is always a visible lesion, manifesting sometimes the morbid process which constitutes the disease, sometimes only the ultimate result of that process. The second class, that of " functional diseases," is less definite, comprehending (1) those diseases that consist only in a disturbance of function, and are there- fore properly so designated ; and (2) many diseases which have this in common with true functional disease, that they are transient and not permanent, and that they are not known to depend on organic changes. But there is also a large class of diseases in which no constant lesion has been discovered, but which are not transient, and cannot well be placed in either of these classes. This simple classification is therefore inadequate. It may be well to consider in what respect it needs alteration to meet the requirements of our present knowledge. The term "organic disease," as commonly used, means visible disease. But visibiUty is relative ; it depends on the means of vision. The application of the microscope to pathology immediately increased the range of organic disease, and a similar increase has resulted, in our own day, from the use of staining agents, which render visible many changes that could not before be seen. Still it remains true that the degree of alteration determines visibility. Molecular changes in nutrition, considered as such, must be colossal to be detected. Such VOL. I. 1 2 INTRODUCTION. alterations, not sufficient to be seen, but still considerable, probably constitute the morbid process in many diseases that are commonly classed as " functional." Hence we may distinguish a class of " nutri- tional diseases " as to a large extent distinct from those that consist in a mere derangement of function. While distinguishing these t"wo classes, we cannot entirely separate them ; nutrition and function are mutually dependent, and prolonged functional disturbance must deter- nune nutritional change. Visible disease varies much in nature and degree. Some forms can always be seen with the unassisted eye; they change the shape or colour or consistence of the part. Other forms can be detected only with the aid of the microscope ; while many may be seen with the unassisted eye when their degree is considerable, and only by means of the microscope in their early stage or when in slight degree. It is convenient to term such alterations, the visibility of which is alto- gether a matter of degree, " structural diseases." Thus we may dis- tinguish four pathological classes of disease of the nervous system : 1. Organic disease (or " coarse " organic disease) ; such as tumour, haemorrhage, softening. 2. Structural disease ; such as most forms of sclerosis. 3. Nutritional disease; such as general paralysis of the insane, paralysis agitans. 4. Functional disease ; such as reflex convulsions, and many forms of hysteria. In the first class the morbid process always begins outside the nerve-elements themselves. In the second class it may begin in them or outside them. In the third and fourth classes these elements are probably always primarily affected. Such a classification helps us to obtain clearer views of the primary relations of disease, but is not convenient for systematic description. For this a hybrid system is necessary, in which organic and structural diseases are classified according to their seat, — in the nerves, spinal cord, or brain. With each group may be placed some nutritional or functional maladies of local incidence. The bulk of these diseases are, however, best considered separately, after the organic diseases have been described, since many of them are of wide distribution or uncertain seat. Classification has two purposes to serve. It serves to bring out the differences in the nature of disease, and thus to define our conceptions and make clear our distinctions. But this purpose is less obtrusive than the second, — to furnish us, as it were, with shelves on which to place our conceptions, and labels with which to ticket them, so that we may find them when we need them and study them in a useful order with the least loss of time. Even if our knowledge were perfect, it is not likely that any scientific INTRODUCTION. 3 classification founded on natural distinctions would serve the prac- tical needs of an arrangement for use. Our present knowledge is un- questionably so very far from perfect as to be inadequate even for a complete natural classification ; wliile an attempt to construct one of this character that shall be also of practical convenience is a mere waste of time. For use, we must divide where we ought only to distinguish ; and we have to place near together, for convenience' sake, maladies that should be not only far from each other, but sometimes far from all others. Yet it is useful to attempt, if not to classify, at least to distinguish the chief pathological groups of the morbid processes that are commonlj regarded as diseases of the " nervous system," and are so designated Unserviceable as a practical division, the attempt affords a general vier*.' of the nature of the maladies, including the various influences to whioa they are due, and therefore by which their nature is determined. The view that is obtained is not less usef id because the groups that are, in the mass, well defined, are perceived to have connecting links when their borders are scrutinised, or are even found here and there to blend in places where a demarcation can only be artificial. We perceive thus that elements are common to more than one, and such elements may be thus more clearly discerned, and their importance is more ckarly re- vealed. The first great distinction, which is indeed a cleavagG running through all the varieties distinguished for practical convenience, is that of primary seat. Some diseases begin in the nerve-elements, others outside them, in other structures. These structures have widely different pathological relations. The bones which protect, the fibrous tissues that invest and support, the vessels which convey the blood to or from the nerve-structures, bring the diseases of these structures into connection with most chronic and acute constitutional diseases ; the blood itself, altered by numerous and widely different affections, frequently produces disturbance of function or of structure, and multiphes the relations of disease of the nervous system to an extent that is to us indefinite, and potentially is all but infijiite. Not only does the blood cause disease by the direct influence of its changed constitution or the morbid agents it bears, but the physical conditions of the circulation, by excess or deficiency of force, and the passage in it of bodies that can obstruct the arteries, involve a direct relation to morbid states of the heart, which is frequently obtrusive. The affections which constitute connecting links between the two general classes of disease, those in which the nerve-structures suffer primarily and suffer secondarily, deserve a general notice. Some of them present to view certain pathological features which are of great importance, and which we have only lately become able to perceive dis- tinctly if not yet clearly. 4 LNTEODUCTION. The variotis morbid growths are also, for the most part, diseases only in, not of, the nervous system, although one variety of neoplasm affords another illustration of the connection between the two classes ; gliomata connect extrinsic growths with diseases that are primarily of the nerve- structure. The supporting neuroglia, different from the nerve- structures as it seems, and indeed is, consists of a residue of the embryonal tissue from which the nervous elements were developed. In its nutritional tendencies it presents a relation to the nerve- structures which, though definite, is opposite ; it overgrows when the latter decay, and thus gives rise to the condition of secondary " sclerosis." Its growth seems normally to be restrained by the vitahty of the higher tissue, and becomes exuberant as soon as that of the latter is lessened. It may persist in tracts, large or small, when there is a congenital arrest of development, such as gives rise to the cavities called " syringo- myeha ; " this persistence is especially important because the tissue may cease to be quiet, may grow and develop into the definite and dangerous condition kaown as " central gliomatosis." But the neuroglia, as the " connective tissue " of the central structures, shares the lower morbid tendency of the interstitial tissue of all organs. It is by an overgrowth of tlois, in random foci, pi'esenting at first some of the features of inflammation, that " insular sclerosis " develops, while the neuroglia also takes a chief part in all forms of interstitial inflammation in the brain, cord, and nerves. Its secondary overgrowth in degenera- tion of the nerve-structures varies in amount and in energy ; even when secondary, it seems occasionally to assume an independence which makes it excessive, and an energy which involves some of the features of inflammation. We have to distinguish from the primary interstitial changes, those acute processes in which the nerve-structures suffer primarily, but with rapidity. When they undergo slow decay we call it " degeneration," but an acute destructive change may take place so rapidly as to resemble "parenchymatous inflammation" — i. e. inflammation in which the primary element is in the proper functional structures of an organ. Such changes belong to the group of diseases that are truly of the nervous system, but are not always readily distinguished from the inter- stitial inL^mmations, since the interstitial tissue and vessels may parti- cipate in the more intense processes. Their course presents aU gradations, from the most acute to chronic forms, but even in the former it is often remarkable how small is the share the connective- tissue elements take. These processes have become, of late, very im- portant, on account of the extent and degree to which they can be traced to toxic influences. They constitute, in slow form, the systemic degenerations of the central nervous system, and also, in both slow and rapid forms, the varieties of toxic peripheral " neuritis." The former, as well as the latter, have been extensively traced to the influence of blood-states. But as chronic "degeneration," they are also often due to defective vitality, or imperfect vital endurance, senile or premature, INTRODUCTION. 5 occurring in late life before otter structures decay, or as isolated failure soon after development is complete. The latter class is represented by the diseases of which " hereditary ataxy " is a type. The toxic influences -which are thus effective seem, so far as we can trace their nature, to be chemical. They may be metallic poisons — or the simpler chemical substances of organic origin, as alcohol — or com- plex organic compounds, either received from without or, more often, formed within the body. They are often formed within the body by the organisms that give rise to " acute specific diseases," as has been clearly proved in the case of diphtheria ; to the same mechanism many nervous sequelse of acute diseases are apparently due. These poisons, especially those of organic origin, present the remarkable feature of a special tendency to influence certain nerve-structiu"es, that we are only able to distinguish from others by their difference of function ; underlying tliis must be some minute difference of consti- tution which renders them more susceptible to the particular chemical compounds. These structures suffer most where their vitality is least, — for instance, the ends of the uei^e-fibres, — the parts farthest from the nerve-cell of which they are the processes. Thus many toxic agents act on the extremities of the long sensory or motor nerves in the limbs, causing " degenerative peripheral neuritis," while a similar degeneration of the fibres of the pyramidal tracts of the spinal cord (the processes of the motor cells of the cortex) constitutes " lateral sclerosis." The motor fibres of the limbs are processes of the cells of the anterior grey matter of the cord ; the sensory fibres proceed from the cells of the ganglia in the posterior nerve-roots. Of the latter, those which seem most prone to suffer are the afferent fibres from the muscles. In loco- motor ataxy these nerves suffer fii-st, apparently from a toxic agent which is a result of syphilis, and acts also on the other processes of these ganglion-cells — those which become the fibres of the posterior median columns. These ascend the cord, but depend for their vitality on the cells of the posterior ganglia. Thus the degeneration in the spinal cord, the " posterior sclerosis," and the changes in the peripheral nerves, are but parts of the toxic effect on one set of "neurons." The afferent nerves from both skin and muscle suffer, moreo\^er, from many other toxic causes, and, alike in alcoholic neuritis and in diphtheritic palsy, we may have a close resemblance to locomotor ataxy. A corresponding lesion underlies the correspondence of symptoms. The special susceptibility of the muscle nerves is the cause of the frequency, and early date, of the loss of the knee-jerk, and of the significance of the symptom. Other toxic agents influence, not the peripheral ends of the chief processes of the cells, but the structures in which nerve-energy is produced in the central mechanism. Such, for instance, is strychnine, and the strychnine-like products of the organism of tetanus ; while one element in the production of the cui-ious disturbance of chorea seems to be the action on the elements of the motor cortex of some 6 INTRODUCTION. poison allied to, but not identical witli, that which causes acute rheumatism, and is probably a complex organic chemical compound. Eelative deficiency in the power of resisting toxic agents must be ascribed to imperfect vital energy, a lower degree of the energy of life that maintains nutrition. Such imperfection is manifested by a class of cases in which failure of nutrition occurs spontaneously ia certain structures, either in late life, as in many cases of senile muscular atrophy, or labio-glossal paralysis, or senile braia failure, or paralysis agitans, — or else soon after complete development is achieved, as in the so-called " hereditary ataxy " and its congeners. Moreover it is possible that a slight difference in the power of vital endurance in some structures, causes a greater readiness to suffer degenerative changes in middle life under acquired influences. The toxic agents which can thus act on the nerve-structures and impair their nutrition and function are numerous and varied. They may be derived directly from without, may be produced within the body by the organisms of disease, and may be produced by disordered chemical processes apart from external influence, or by an external influence that becomes effective through a peculiar predisposition. They present relations to those rheumatic poisons which act on the fibrous tissues and on other stnictures. Exposure to cold, apparently the same, may cause in different persons — a general catarrh, local inflammation (as tonsillitis), acute rheumatism (with or without endocarditis), spinal myelitis, or peripheral neuritis, apparently according to the nature of the toxic agent generated, determined by the constitution of the indi- vidual. A slight difference in the initial effect may determine a divergence in the chemical processes under the influence of life, and the ultimate result is the same in no two individuals, and may be very different. GENERAL SYMPTOMATOLOGY. SYMPTOMS AND TSUIR INfTESTiaATION. The nervous system is almost entirely inaccessible to direct obser- vation. The exceptions to tliis are trifling: the termination of one nerve, the optic, can be seen ; some of the nerve- trunks in the limbs can be felt, either in the normal state or when enlarged by disease.* As a rule, the state of the nervous system can be ascertained only by the manner in vs^hich its vrork is done, and morbid states reveal their presence by the derangement of function which they cause. The functions of the nervous system are often divided into mental, motor, and sensory ; but they are far more extensive than those words denote. The functions of all the organs of the body, all states of the blood-vessels and hence of the circulation within them, and even all processes of nutrition, are under the control of the nervous system. The disturbance of nerve-function produced by disease is conterminous in extent with the human organism. Our knowledge of these symptoms is constantly increasing in range and in degree. They differ, however, very much in relative importance. Some occur more frequently than others, and are more direct in significance. Many have a special relation to certain parts of the nervous system, while others occur in diseases of all parts. It may be well, at the outset, to describe the characters of some of the most frequent symptoms ; while the more special symptoms can be conveniently considered when we deal with diseases of that part. MoTOB STMPTOMS.f — ^Disturbance of motion is one of the most • To the new X rays, unfortunately, the nerve-centres are opaque and in:icce— sible, and the nerves differ too little in transpHrency from the other ti-snes to permit them to be seen, while their course is seldom such as to bring tliem into conspicuous distinction from otlier structures. + Some modification of the word kinesis (akinesis, &c.) is sometimes used to designate motor symptoms. These words seem to me to add nothing to our know- ledge or to its clearness — certainly nothing to compensate for their cumbersome character J and the definite additional! new word-^ make to the infonnati'ai tliiit has to be acquired is not always sufiiciently weighed against their supposed advantage. 8 SYMPTOMS. common effects of disease. Movement is produced by muscles, but the muscles are excited to contraction by the nervous system. Most alterations of motility, both defect and excess, are due to its derange- ment. The conditions are very few in which motor changes originate in the muscles themselves. Defect of movement is of muscular origin only in some cases of primary alteration in the nutrition of the muscles. When there is a general impairment of nutrition, the muscles participate in this ; they are ill-nourished, and therefore feeble. Such a condition is met with in chronic wasting diseases, in anaemia, and as an acute affection in all acute febrile diseases. This is Ihe chief cause of the muscular weakness that so often results from fevers ; it may even proceed to the degree of causing visible changes in the aspect of some fibres. In a few chronic diseases the muscles undergo a primary altera- tion. One is the disease known as " pseudo-hypertrophic paralysis," a special form of a wider malady, in which there is atrophy of the muscles, due to their own defective power of vital maintenance. Rheu- matic and other inflammations, commonly interstitial, may greatly impair their power, first by the pain contraction causes, and then by damage to the nerves in this tissue, a state to be distinguished from the primary affection of these endings themselves. In almost all other conditions, loss of power in the muscles is dependent on the state of the nervous system, either directly or through defective nutrition of the muscles, or both. The nutrition of the muscular fibres depends on the motor nerves, although we are still ignorant of the precise nature of that dependence. The subject will be referred to again in the special account of the changes that result from injuries to the nerves. So also with increased and involuntary muscular action. We know little of what has been termed " idio-muscular contraction," — that is, contraction originating in the muscle itself. Whenever the whole of a muscle contracts, the contraction is due to an influence acting on aU the fibres, and this is generally from the nerve-centres. Even muscular "tone" is dependent on the connection of the muscle with the nerve-centre, since it ceases when the connection is de- stroyed. It is possible that the extreme degree of the contraction in cramp is the effect of a tendency in the muscle itself. When the shortening exceeds a certain degree it becomes fixed in a peculiar manner, which seems as if it were due to a tendency in the fibres to pass beyond the power of relaxation. Contraction of the whole of a muscle may also result from mechanical influences acting on every part equally, as in traction. But these exceptions occur under special conditions. The partial contractions that are termed " fibrillary " are probably local, since they are so readily produced by mechanical stimulation, such as a tap on the muscle. Yet fibrillary contractions, although sometimes local, may be often of central origin. This is also true of the flickering contractions that are so common in persons whose MOTOR. 9 nervous system is enfeebled, the " live flesh " of popular language. They may occur in any muscle, from the orbicularis palpebrarum (in which they are most common) to the gluteus maximus. After damage to the nerve-fibres to the muscle they occur in special degree ; they are often frequent for years in the calf muscles after sciatic neuritis. Paralysis. — Defect of movement may present every degree from slight weakness to absolute loss. There may be inability even to make the muscle contract, or the voluntary contraction may occur, but be too feeble to move the parts to which the muscle is attached. The latter difference is to some extent relative, since it varies with the readiness with which the part can be moved — i. e. with the resistance to be overcome. A contraction that will flex a finger may be insufficient to flex the wrist. The difference may vary in the same part according to position. A degree of power in the flexors of the hip, that will move the leg when the patient is lying on his side, may be insufficient to do so when the patient is lying on the back. This difference is even more conspicuous in some other muscles ; paralysis of the extensors of the elbow may be discovered only on an attempt to raise the hat: in many positions extension is due to the weight of the arm, much more than to the muscles, so that considerable weakness may be unobserved. The term " paralysis " has long been applied to all degrees of defect of power, a distinction being made between complete and incomplete paralysis. Partial loss of power is also sometimes termed " paresis." The advantages of "paresis" over the word "weakness" are chiefly psychical, and depend on the popular horror of " paralysis,'' which has become specially associated with complete loss of power, and the idea of incurability seems inseparably attached to the term. Our means of estimating defects of muscular contraction are very imperfect, in consequence of the peculiar and various form>' of move- ment which are produced. An instrument to measure the f o»^e exerted is called a " dynamometer," but any simple form of insti-Mment can have only limited application. Several have been devised, tut that in general use consists of an oval steel ring, which can be narrowed either by compression applied to its smaller diameter or by tractioxi applied to its longer diameter. The change in the shape of the dyns^-mometer, and therefore the force exerted, is shown by the movement of an index on a scale that has a double graduation, a closer for com- pression, which is easy, and a wider for traction lengthways, which is difficult. This form of dynamometer is known as " Charriere's," from the name of its first maker. Another less convenient form was devised by Duchenne. These instruments are chiefly x^sed for the measurement of the grasp. The estimation of the strength of other movements is practicable, but not easy. The observer opposes the movement by means of the instrument, and notes the resistance that can be overcome. Thus pressure applied through it just a^bove the patella, to force down the raised thigh in the sitting posture, shows 10 SYMPTOMS. the power of the flexors of tlie hip. The wide variations in strength among different persons renders absolute estimation possible only when the defect is considerable. Slight changes are recognised by comparing the power on the two sides. It should be remembered that the limbs on the right side are normally stronger than those on the left, the rela- tion being about as five to four. Care must be taken to secure uniformity of the conditions under which the observations are made. A careful search would doubtless reveal average proportions between other movements that can be measured. Thus the strength of flexion of the hip, estimated in the way just mentioned, often corresponds to the strength of grasp on the same side. Inco-ordination of Movement. — By this term is meant a defect in the relative time and degree of the muscular contractions by which a move- ment is produced. Every movement is due to the contraction of a series of fibres, which may or may not correspond to the series massed together in a " muscle." Movements, not muscles, are represented in the structure of the brain, and the fibres which, together, cause a simple movement may be in more than one muscle, or may be only part of a muscle. The synergic action of the several fibres, in a definite degree and at a certain time, is essential for the movement. So also is the simultaneous contraction of the opponents of these acting muscles, which are thus steadied ; this antergic * contraction is essential for the exertion of force, and must be often great in degree when strength rather than amount of movement is required. It must also be lessened automatically to permit movement. (The process will be considered in connection with the functions of the spinal cord.) Defect in the opponents does not interfere with movement, but it prevents the exertion of force, by permitting the movements to be too great. It is not customary to apply the term "inco-ordination" to any derangement of movement except that which is irregular in time. There may be also irregularity in degree, but it is when the contractions have not the normal duration, or are not synchronous, or not in due sequence, that the conspicuous irregularity occurs to which the term is applied. This is also often called " ataxy." Its manifestations differ in character according to the character of the movement. The variations are so great that it is not practicable to describe them, nor is it necessary, since aU have the general nature just stated. It is also not easy to estimate the inco-ordination so as to permit definite record. When the movement of the arm is affected, the degree may be estimated by making the patient try suddenly to touch, with the point of a pencil, a spot on a sheet of paper placed before him, his eyes being closed at the moment of the attempt. After a certain number of attempts the average distance from the spot of the dots he has made is ascertained, and this, compared with the result * I use this term because we have noiid to express antagonistic co-operation. This ■« svnclironous with that of the acting muscle, but not synergic. ^ MOTOR. 11 given by a normal individual, affords a numerical indication of the degree of in co-ordination.* The method is effective, although the result is perhaps scarcely worth the trouble. Whenever there is inco-ordination, spontaneous movements occur if the patient tries to hold the limb in a certain posture ; the variation in muscTilar contraction prevents jBxation as well as disorder in movement ; co-ordination is as essential for steadiness of uniform contraction as for the steadiness of the varying contractions of movement. These involun- tary movements constitute a delicate test for the presence of ataxy. All spontaneous muscular contractions derange those that are due to the will, and movement is disordered by any " tremor " which co-exists. The sHght rapid contractions that cause " tremor " may, indeed, occur only as voluntary movement, and there is a gradation of disorder from simple inco-ordination to that which may be called " tremulous." So also more extensive spasm disturbs movement with which it coincides, and energetic contractions of involuntary nature may be excited by a volitional impulse. Hence, just as simple ataxy may pass into tremor, so, on the other hand, there is a gradation by " jerky inco-ordination " to wide sudden movements, the violence of which obscures the element of mere disorder. It is necessary to distinguish co- ordination and the direction of movement to a definite end. The motor process for the latter depends on sensory guidance, chiefly on the senses of touch and sight. A semp- stress with loss of seDfa ion in the fingers cannot sew unless she constantly watches them. A compositor, whose sense of touch is dulled upon the tips of thumb and index finger, cannot pick up the type, or if he does pick it up may drop it again, unless he constantly watches the movement. There is also a guidance from the afferent nerves of the muscles, but this is related to co-ordination proper rather than to the direction of movement, and it wiU be more conveniently considered in connection with the functions of the spinal cord. Indeed, the mechanism of co-ordination, and its special factors, can only be discussed in that connection. Spasm. — Involuntary muscular contraction, when considerable in degree, termed spasm, is always due to the influence of the nervous system. It is a frequent symptom of disease. Three chief varieties may be distinguished, but iatermediate and combined forms are often met with. (1) We may have, first, a single isolated very brief contraction of one or more muscles. (2) Separate contractions may occur in rapid succession, a second commencing as soon as there is relaxation of the muscle from the first contraction. This is tenned " clonus," or " clonic spasm." The relaxation of one is often incomplete when the next con- traction begins. (3) There maybe a persistent contraction in which no relaxation can be perceived. This is tenned " tonic spasm." (1) It will be i-emembered that muscles, as long as they are connected • lihx, ' Neur. Centralb.,' 1884, p. 83. 12 SYMPTOMS. with the nerve-centres, are never in a state of perfect relaxation. There is always a certain degree of persistent slight contraction of the fibres, which keeps them adapted to the distance between thair attachments, so that the substance of the muscle presents always a similar degree of firmness. This physiological " tone " is due to a continuous action of the centre on the muscles, through the motor nerves ; but this action is apparently determined, in degree at least, by the sensory impressions from the parts, and especially from the muscles.* Tonic spasm may be regarded as an augmented degree of this state, due to various causes. Although it necessarily depends directly on the action of the centres in the spinal cord, this may be due to the augmenting influence of the cerebral centres, or to diminution of the latter, permitting insubordinate activity, and is often clearly the result of a reflex process. It must be distinguished from structural shortening of the muscle. The distinction is easy^ because tonic spasm can always be overcome by gentle, steady traction, while structural shortening cannot be thus removed. The latter may result from long-continued tonic contraction ; nutritional changes alter the structure of the muscle and fix the elements, espec-ally the interstitial tissue, in the state of contraction. It occurs whenever muscles for a long time are unextended by their antagonists, and so results from the long-continued maintenance of a certain posture, and also in extreme degree from paralysis of opponents. Its influence on the joints and the parts moved causes the various de- formities that result from local palsy. The tonic spasmodic shortening which can be overcome is often spoken of as " spastic." It is some- times also distinguished as " contracture," the term " contraction " (which really includes all forms of spasm) being then apphed in a narrow sense to the fixed shortening. (2) Single muscular contractions vary much in extent and duration ; when partial they sometimes, as already stated, seem to be of local origin. When more extensive they depend on the nerve-centres. (3) Clonic spasm consists of a series of brief contractions, each of which corresponds to that which is caused by a single induction-shock applied to the nerve. This has a definite duration of one tenth to one twelfth of a second, but it is often prolonged by the force which the contracting muscle has to overcome. In the serial contractions to which the term •' clonus " is applied there is also an interval between the end of one and the commencement of another, occupied by the process of stimula- tion. The '-foot-clonus" to be presently described, which consists of a series of such contractions, varies in frequency from five to eight or ten per second. The contractions in " tremor," as seen for instance in " paralysis agitans," have a somewhat greater average frequency. • Jendrassik ('Neur. Centralbl.,' 1896) has endeavoured to estiinate tho degree of tone by the resistance of the muscles to passive extension, and finds it greater in spastic paraplegia, and less in tabes tbMU iu normal states. The latter, however, pre- sented snch wide variations as to preclude absolute inferences. The amount of the extending force applied seems to need more careful adjustment. SENSORY. 13 Tetanic spasm is produced by the blending of clonic contractions whicli may be so fused that the contraction is uniform, and is then identical with tonic spasm ; or there may be commencing relaxation of one before the next contraction supervenes. This is chiefly seen as such spasm develops or lessens. .The passage of tonic into clonic spasm is well seen in the severe epileptic convulsion, in which the fixed spasm becomes first vibratory, then intermittent, and at last remittent. Sensory Symptoms. — Altered sensation is another very common symptom. It has often to be searched for, because a significant defect may be unknown to the patient. Each form of sensation, touch, temperature, and pain, must be separately tested, since one may be affected and not another. The affection of one form only is sometimes of important diagnostic significance. Stnsibility to Touch. — The structures that subserve tactile sensibihty are stimulated chiefly by motion — by change in contact. Prolonged contact, unif oiTQ in its degree and place, is perceived but little, and only by close attention. It is the change that excites a nerve impulse ; the commencement of contact is more effective than its cessation, but in each case rapidity of change chiefly determines the result. a firm pressure may be scarcely noticed if produced very gradually, while a sudden touch is observed, however light. In testing tactile sensibility care must be taken that the instrument employed does not give an impression of heat or cold, lest the patient perceive by the sense of temperature that which he cannot perceive by the sense of touch. The observer's finger may be used, if it is not cold, or the skin may be touched with a feather, a piece of string, of India rubber, &c. The eyes of the patient should be closed during the examination, and, since he is apt to fancy that he feels a light touch when he does not, he should occasionally be asked if he can feel, when no contact is made. But it is easy to make the test too fine. Where the skin is thick, or sensibility is normally low, a Hght touch with a piece of string or a feather may normally be unperceived. Loss of sensibility to touch is teinned " anaesthesia," but this word is often applied loosely to all forms of impaired sensibility. In examining the tactile sensibility it is important to ascertain not only whether the patient can feel, but whether he is able to recognise the place touched, — ^whether he can correctly " locahse " the sensation. For this he must be asked not only whether he feels the touch, but also to say or point out where he feels it. The part touched should be frequently varied. Another test for tactile sensibility depends on the fact, ascertained by E. H. Weber, that the distance apart at which two points are discriminated is nearly the same in different individuals in the same part of the body, although it varies much in different parts of the body. The normal distance being laiown, the increased distance at which the points have to be placed for their discrimination is a measure of the degree of defect. The points should not be so 14 SYMPTOMS. sharp as to occasion pain. Common compasses may be employed, but the most convenient " aesthesiometer " is one contrived by Sieveking, in which the points are attached to a graduated bar. The greater the degree of tactile sensibility, the nearer together can the points be, and still be discriminated. The distance at which they are normally distin- guished must be known before any inference can be drawn. The most important average distances, ascertained by Weber, are as follows ; — The distance is smallest, i. e. the sensitiveness is greatest, at the tip of the to ague, where the points are discriminated when only 1"5 mm. apart. Then come, in order of sensitiveness, the finger tips, 2 to 3 mm. ; the hps, 4 to 5 mm. ; the tip of the nose, 6 mm. ; the cheeks and the backs of the fingers, about 12 mm. ; the forehead, 22 mm. ; the neck, 34 mm. ; the forearm, lower leg, and back of foot, 40 mm. ; the chest, 45 mm. ; the back, 60 mm. ; the upper arm and thigh, 75 mm. Slight variations exist in different individuals, and a deviation from the normal that is tmiform in degree throughout the body is probably physiological. In using this test it is necessary to touch the skin with the two points at the same moment, and with equal pressure. The examination requires time and patience, and the results are considerably modified by the intelligence of the patient. Moreover the power of discrimination is increased by practice. It is rare to obtain a con- clusive result unless there is a degree of defect that causes a slight absolute loss. For these reasons the practical value of the test is less than was at first anticipated, and it is not often employed. It is most useful for the estimation of changes of sensibihty in the same person and the same part. Curious modifications of tactile sensibility are sometimes observed. In one of these, a single touch is felt as if it were two or even three, a condition that has been termed " poljsesthesia " (Fischer). In another, an impression on one part is referred to some other part, usually in the same hmb, rarely in another limb.* In another variety, an impression on one part has been referred to the corresponding place on the opposite side of the body ; this has been termed " allocheiria " (Obersteiner) . Perception of the degree of pressure on the skin is probably sub- served by the nerves for tactile sensibility. It may be estimated by simple pressure apphed through any instrument, or by small weights, or by an instrument contrived for measuring the tension of the pulse in which, by means of a spring, the part tested must be supported, so that the muscles are not brought into action. The point to be ascertained * In most i)ersons tliere are spots in the skin whence a painful sensation seems to dart to a distiint place; e.g. a prick on tlie thigh in a limited area may be felt also as a sharp pain near the scapula. This shows how structural connections must exist favouring tlie "reference" of sensation to a distance from the nerve stimulated. Another instance of tiie same perverted reference is presented by the frequent neuralgic pain in one jaw due to a carious tooth in the other jaw, which seema painless. SENSORY. 15 is the minimum variation that can be recognised. In health this is about one twentieth of the total pressure, whatever the latter may be (Weber). The sensation in the skin caused by electricity, especially by faradism, does not always correspond to that due to other stimuli. It has been thought to depend on a special form of sensibility, but the evidence of this is insujGB.cient. Its features and their meaning have yet to be ascertained. Sensibility to pain is subserved by what are called nerves of " common sensibihty." It may be tested by a prick or a pinch. For a prick, too fine a point must not be used, not only because a sharp point may penetrate the skin, but because, in the less sensitive parts of the skin, where the nerve-endings are not close together, a fine point may be unfelt at one spot, although felt readily at a place close by. Nothing answers better than the point of a quill pen. The faradic current may be employed to test sensibihty to pain, wire terminals being most suitable for the purpose. Its advantage is the delicacy with which it can be graduated ; but it does not furnish any absolute standard, and needs more study before it can be usefully employed. Sensibihty to pain may be changed with or without sensibihty to touch. Its loss is termed " analgesia," but is often included in the general term " anaesthesia." A painful sensation may be felt more intensely than normal ; this is usually called " hyperaesthesia " — a general term for increased sensitiveness ; sometimes, with more pre- cision, " hyperalgesia." Occasionally a touch on the skin gives rise to pain, but it is probable that this is due to the stimulation of the over-sensitive nerves of common sensibility, and is not an intensification of a tactile sensation. The fact that touch may be perfect, although no paia can be caused, makes it difficult to conceive that the nerves of touch can subserve pain. Both tactile and painful impressions may produce sensations that are abnormal in character, described as " thriUing," " tiaghng," &c. This perverted sensation has been termed " paraesthesia," or " dyssesthesia," words that have also been apphed to purely subjective sensations. When a prick is perceived as touch, pain being lost, care is needed that the patient shall clearly know what is desired. Since there is often delay, when there is not loss, he should be told to say " touch " or " prick " the instant either sensation is perceived. When sensibility to pain is diminished but not lost, the test must be kept uniform. Another source of error is then occasioned by the readiness with which the patient may mistake the degree of pain he is required to recognise, and by the fact that his idea often varies in the course of the examina- tion. He may thus deny that he feels a prick as such at a part where presently he says he does, and this quite honestly, the sensation being really the same. It is probable, indeed, that this is the most frequent cause of the conclusion that the state " varied in the course of the examiiinfion," or that "the patient's answers were unreliable." Sensiotlity to temperature is usually affected with sensibility to pain, 16 SYMPTOMS. but often not in t!ie same degree, and one may be impaired withont tlie other. There may be an absolute inability to recognise either heat or cold as such, or slight degrees of each may be imperceived while con- siderable degrees are recognised correctly. In the latter case there is impairment of the power of perceiving differences in temperature, analogous to the defect in the perception of differences in pressure. There may be also perverted sensibility, whereby hot objects feel cold, and cold objects hot. The pain which extreme degrees of temperature normally produce may be felt with undue readiness, or less readily than normal. When the interval is increased that elapses before a sensation of pain is felt, there is a similar delay in the sensation of temperature. It must be remembered that, in health, this sensation is less quickly produced than that of pain, because time is required to raise the temperature of the sldn sufl&ciently to enable the heat to stimulate its nerves. For rough examination, hot and cold spoons may be employed, or a hinged tongue depressor, one half of which is warmed, or two similar test-tubes, one containing hot and the other cold water. Both heat and cold must be sufficient in degree to be unquestionable, so that the doubt of a patient is certainly pathological, and not due to uncertain " lukewarmness." For ascertaining the power of differential discrimination, large test-tubes may contain water at known temperatures, indicated by a thermometer in each. It is always necessary to test separately the sensibility to heat and to cold, as there is reason to beheve that they are subserved by different nerves. If very minute points of the skin are examined, it has been found that at some points only heat, at others only cold, is perceived. The stimulation of points of the skin by electricity is said also to show that at some points the peculiar electrical sensation is produced, at others a sensation of cold, at others one of heat. Further, the points identified as " cold points " and "warm points " by the one method are said to correspond with those ascertained by the other.* The conclusion from these observations is confirmed by the fact that in disease the sensibility to heat and to cold may be affected in different degrees. Commonly, however, the defect in the two corresponds; accuracy in the comparison is beset with great difficulty. Muscular Sensibility. — The term "muscular sense," as often used, includes more than one form of sensation. There is, first, a true mascular sensibility. The muscles are abundantly supplied with sensory nerves, which end in the interstitial tissue between the muscular fibres in special structures, fusiform in shape, and hence termed " muscle spindles." These have long been known, but have lately been investigated by Sherrington, Batten, and others. They are of considerable length, some nearly half an inch long, and have a special relation to the afferent fibres, which seem to begin in them, * Blix, ' Zeit-chr. f . Biolocrie,' Bd. xx, p. 141 ; Eulenberg, * Zeitschr, f. klin. Med.,' Bd. ix. Heft 2. The observations liave also been corroborated by Goldscheider and HL-rzen, but the subject deserves further investigation. SENSORY. 17 although the strange fact that they contain striated muscular fibres makes it probable that motor fibrils may enter them. Their relations, degenerative and morbid, have yet to be worked out, but we may assume that it is probably in them that the afferent impulses arise. Such impulses are excited especially by pressure, and by traction on the muscle. Thus a squeeze of the calf causes a muscular sensation of an undeniable quality, and strong passive flexion of the foot on the leg causes a sensation which is distinctly produced in the muscle. The nerves are, moreover, strongly stimulated when the fibres are widened by the extreme contraction of "oramp," which causes acute pain. It must be ascribed to the compression of these nerve- endings, since no afferent impressions seem to come from within the fibres. It is thus a proof of their susceptibihty to pressure-excita- tion. After cramp, moreover, the nerves are left in a state of such exalted excitability that even slight extension of the muscle gives rise to pain, although such extension has no sensory effect in the normal state. Every one has experienced the effect. We shall afterwards see the importance of the fact that the nerves are chiefly stimulated by these two mechanical processes. The muscular pain caused by electrical stimulation, as distinct from the pain felt in the skin, may be due to the stimulation of the afferent nerves in excessive degree, or to the effect on them of the muscular contraction that is produced; the former is the more probable. But these sensations of pain, although due to "muscular sensibility," are not included in the term "muscular sense." They are, however, of great importance on account of the conclusive evidence they afford that afferent impulses come from muscles and as to the way in which they are produced. The chief knowledge that is ascribed to the "muscular sense" is that of the character of movement and posture due to the action of the muscles, of the degree of movement and energy of contraction, and also of the character of passive movement (by an external force) and of posture when the muscles are at rest. It is evident, however, that here we have two very different conditions, in one of which there is much activity of all the motor elements, nervous and muscular, while in the other these are almost at rest, only such gentle action persisting as maintains the " tone." Except in absolute relaxation, there is probably continuous stimulation of the afferent nerves by this tonic state of the muscular fibres. In active contraction, this stimulation is far greater, and activity of the motor nerve-centres is added. Hence two elements *re comprehended in the term, and must be separately considered. Our knowledge of active states of the muscle is due, at least in some measure, to the effect on consciousness of the activity of the nerve- structures causing the movement. The proof of this consists in three facts. (1) In palsy of an ocular muscle, objects seen are referred to the position (in relation to the body) that they would occupy if the movement corresponded to the innervation ; it is the latter, i. e. the VOL. I. 2 18 SYMPTOMS. activity of the centre, to wliicli the perception corresponds. (2) After amputation of a limb, a person who makes an effort to move the lost part seems to feel as if he did move it. (3) In some convulsions beginning locally, slight attacks may be attended "with a feeling that the arm is raised above the head, or otherwise moved, when it is hanging by the side. These facts show that the central motor process is an important source of our knowledge. But to its effect must be added that of the impulses from the muscles, about to be described. Our knowledge of rest-posture and passive movement must be derived from incoming impulses. These are not from the skin ; the sense of posture may be lost when cutaneous sensibihty is normal, and perfect when this is much impaired. This is observed in tmilateral lesions of the spinal cord, and in other diseases. The chief source of these perceptions must therefore be the deeper afferent nerves, those of the muscles and joints, perhaps chiefly of the muscles. These afferent impulses are no doubt continuously generated, but do not influence consciousness as definite sensations. They certainly in- fluence the activity of the motor centres of the spinal cord, and there is reason to think that they pass, in part, to the cerebellum, and act through it on the cerebral cortex, determining and assisting in regu- lating its activity. This influence on the motor centres, by the effect it produces, is apparently one chief cause of the perceptions of these passive states. The active state of the motor centres of the cortex, however it is produced, has an effect on consciousness and enters into perceptions though no sensation results. This may be combined either with true sensation from the parts concerned, or with the result of stiU slighter impulses, to be discerned only by close attention, to the joints, skin, &c., of which we seem, at first, to be altogether unconscious. We are thus led to refer our perceptions of passive posture in part to the same structures as give rise to our perceptions of active posture. Our knowledge is the result of such perception, and not of true sensation proper ; — ^we perceive and know that which we do not feel. Our recognition of resistance to contraction affords one of the most delicate tests for " muscular sensibility." It is ascertained by testing the ability to detect differences of weight, i. e. variations in the resistance to contraction. In tliis examination the patient's eyes should be closed, and the objects used should be of uniform size. Leather balls like small cricket balls, containing various weights from two drachms to two pounds, are in use at the Queen Square Hospital for this purpose. To eliminate as far as possible the stimulation of the cutaneous nerves, we may (1) reduce it to a minimum area, placing the weights in a bag suspended by a string to the part to be tested, so that only a small area of the skin shall be pressed upon ; (2) increase the area (Hitzig) , and thus diffuse it in diminished degree ; (3) increase the weight, and therefore the pressure in both area and degree, so that the addition to be discerned shall bear only a small proportion to the total stimulation. REFLEX. 19 Thus we may test muscular sensibility: — (1) by the power of discriminating weigbt. This is greater than in the case of the nerves of the skin, since a difference of one fortieth of tbe total weight can be recognised under normal conditions ; (2) by the sensitiveness of the m.uscles to pressure and traction ; (3) by their sensitiveness to electrical stimulation. It is difficult to test accurately the electro- sensibility unless the sensitiveness of the skin is lost, or is removed, as by the injection of cocain. The power of recognising passive posture is also regarded as a test for muscular sensibility, but it may mean much more, afterwards to be considered. If cutaneous sensibility is normal, the parts handled must be grasped firmly, and pressed on both sides, so that the direction of pressure may not suggest the posture. The patient should be asked to indicate the sensation by putting the limb of the other side into the same posture. Several observations should be made to eliminate the chance of accidental error. Eeflex Action. — Many symptoms of disease of the nervous system are due to derangement of the various reflex actions. These are numerous, and we can now only consider their general characters. Each action is effected through afferent sensory nerves, efferent motor nerves, and a system of nerve-cell-processes, and intervening sub- stances, — the "reflex centre." The centre is usually complex and often extensive, and in it are paths of different "resistance," deter- mining the form of reflex action and its extent, according to the source and intensity of the sensory impression. The reflex centre is between the roots of the sensory and motor nerves concerned, and with them it constitutes what may be termed a "reflex arc." The sensory impulse may not only excite a motor process, it may also pass up to the brain, and influence consciousness as a sensation. It is probable that the two effects are subserved by the same nerve-fibres, so far as the cutaneous nerves are concerned, but some fibres from the muscles pass up the cord without connection with the spinal centres. Further, the reflex centre of the spinal cord is to some extent under the control of encephalic centres — a point of very great importance. Two forms of reflex action must be distinguished. The first is that excited chiefly by stimulation of the nerves of the skin ; the second is produced by the stimulation of deeper nerves, chiefly those of the muscles, in the manner just described. This form is caused, among other ways, by tapping a tendon, and therefore was at first, and still is sometimes, called " tendon-reflex action " — an undesirable name. Cutaneous Reflex Action. — The reflex movements obtained from the skin are excited rather by a gentle stimulation, as a touch, than by a strong, painful impression. They consist of a single movement in most instances, either quick or slow, but often complex, and extensive in proportion to the character of the stimulation effected, the nature of the central mechanism, and the state of the centre. Often muscles at 20 SYMPTOMS. a distance are influenced by a powerful stimulation, either "mtli others or alone. A strong impression may cause a reflex action so wide as to involve most of the muscles of the body. As a rule a painful impres- sion causes quick flexion of a limb, such as to withdraw it from the cause of the pain. Thus a prick near the knee causes a reflex flexion of the hip. In other cases, where withdrawal is impossible, a protective movement results, as in the case of the eyeUds. The sHghter degrees of excitation cause a contraction in the muscles close to the part of the skin that is stimulated, the impulse passing, in the spinal cord, only to the related motor centres. This limitation of the process renders them important in diagnosis, especially when lost on one side (see the chapter on the functions of the spinal cord). The cutaneous reflex actions may be excited at almost any part of the skin, but at some parts they are very definite in cha- racter, and are distinguished by special names. The most important are the "plantar reflex," from the sole ; the " gluteal reflex," a contrac- tion in the gluteus when the sldn over the muscle is stimulated ; the " cremaster reflex," a retraction of the testicle on stimulation of the skin on the inner part of the thigh ; the " abdominal reflex," in the muscles of the abdominal wall when the skin over the side of the abdomen is stroked ; the upper part of this reflex is a very definite contraction at the epigastrium, and has been termed the " epigastric reflex." A series of reflex actions may be obtained in the muscles of the back, the highest being in the muscles of the scapula. Others have been distinguished and named, but this process may easily be carried too far. These spinal reflex actions vary in their excitability in different individuals, and are always more readily produced in the young than in the old. They may be increased or abolished by disease. In the region of the cranial nerves the most important reflexes are those of the eye, — (1) the conjunctival reflex ; (2) the contraction of the pupil on exposure of the eye to light ; (3) dilation on stimidation of the skin of the neck. Muscle-reflex Action ; " Tendon-reflexes.** — The second group of phenomena which depend on reflex action were first systematically studied by Erb and Westphal more than twenty years ago. Attention was called to them in this country by G-rainger Stewart and Buzzard in 1878. They have since been the subject of a vast amount of study and discussion. All occur in muscles that are in a state of slight tension, and are produced by a sudden increase of this tension or by some other sudden mechanical influence, but voluntary contraction superadded to passive tension, diminishes or prevents them. They are distinguished according to their seat, and vary in distinctness, conspicuousness, and the ease with which they are produced according to the mechanical conditions of the muscles and their attachments. The first of these is the jerk of the leg which occurs when the patellar tendon is tapped. It has been called the " knee- phenomenon" KEFLEX. 21 by Westphal, the " patellar tendon-reflex " by Erb, the " knee-jerk " by myself. To obtain the jerk, the knee must be flexed so that the quadriceps f emoris is gently extended. If then the patellar tendon is struck, the quadriceps contracts, and the lower leg is jerked forward if free to move. The blow is given over the space above the tibia where the tendon can yield, so that there is a sudden increase in the tension of the muscle. The most convenient position is with the knee to be tested flexed nearly, but not quite, at a right angle, by being placed over the other knee as the person sits (Fig. 1). But if the leg to be tested is stout, its tension in this position may be too great to Fig. 1. — The Knee jkek. The dotted line indicates the movement which follows the blow on the patellar tendon. Fig. 2. — The Knee-jekk. ileihod of obtaining it when it is not readily pioduced in the ordinary way. permit of any movement. In such case the observer may place his arm beneath the patient's thigh, just above the knee, and rest his hand on the patient's other knee (Fig. 2). Muscular relaxation is sometimes more readily obtained when the legs hang vertically ; or the foot may rest on the floor, and the contraction be felt by the hand placed on the muscle ; the effect of the recoil and of the muscular contraction must then be carefully distinguished. If the bent fingers of each hand are hooked together, the hands pulled strongly, and the eyes closed, the movement is increased in degree — " reinforcement," it has been termed.* It is essential that the flexors also should be free from voluntary con- traction. This contraction may be ascertained by feeling the hamstring tendons, and pressure on these by the fingers often helps to secure re- laxation. The blow may be given by the side of the hand, a percussion hammer (Fig. 2), or a stethoscope with an india-rubber edge to the ear-piece. If the jerk is doubtful, the skin shoxdd be bared. • A useful device suggested by Jendrassik. 22 SYMPTOMS. The same contraction may be obtained by other modes of suddenly increasing the traction on the muscle, especially when this excitabihty is abnormal in degree. A blow on the tibia may be effective, but a method which has much practical convenience is this. When the patient is lying with the muscles relaxed, the patella is displaced downwards by a finger placed across its upper edge ; a tap on the finger in the direction of pressure, so as suddenly to increase the tension, excites the contraction of the muscle whenever there is even slight increased excitability. If the tension is maintained when the excitability is much greater than normal, the single contraction is immediately succeeded by a second, and this by a third, and so on — a series of qtdck clonic contractions, or " clonus,"which will be considered presently in more detail. It may continue as long as tension is kept up, but instantly ceases when the muscle is relaxed. Similar contractions can be obtained by similar measures in many other muscles. That in the muscles of the calf, which causes a move- ment at the ankle-joint, is especially important. If the calf muscles, which are connected with the Achilles tendon, are made tense by gently pressing up the foot, and this tendon is tapped, the muscles contract, causing a slight extension movement of the foot ; just as the muscles of the thigh contract when the patellar tendon is struck. The tendon is unsupported just as is the patellar tendon, and so yields before the blow increasing suddenly the tension on the muscles. A tap on the side of the tendon is equally effective ; but if the tendon is so firmly supported on the other side that it cannot yield, a tap which before caused the contraction will not do so. This is evidence that it is not the mere percussion of the tendon, but the increased tension, which constitutes the stimulation. In cases in which the excitability is excessive — just as sudden tension in the thigh muscles will cause a con- traction, followed by others in a continuous series — so, in such cases, if the calf -muscles, which extend the ankle-joint, are suddenly put on the stretch by pressing the hand against the sole of the foot (Fig. 3), the first contraction is followed by another, and they recur as long as the tension is maintained. This series of contractions, the "foot-clonus" or "ankle- clonus " (or " foot-phenome- non " — Westphal), is a very important symptom. The movement is remarkably uni- form under the same conditions, varying from six to nine contractions per second. By attaching a writing point to the foot, and making it Fia. 3. — Method op eliciting thb FOOT-CLOKUS. EliPLEX. 28 trace a line on a revolving cylinder covered with blackened paper, tracings may be obtained (Fig. 4), which are almost as regular as Ftd. 4. — Tracing- of the Foot-ci.ontts in Paeaplegia. (The tracing reads from right to left.) those of a tuning-fork.* The clonus in the extensors of the knee has the same time, and the two are of the same nature. A clonus quite similar may sometimes be obtained in other muscles — peronei, flexor brevis pollicis. Similar contractions may be obtained in the muscles of the arms. Normally those most distinct are (1) in the biceps and supinator longus, obtained by a tap at the wrist, especially on the radius, to which the biceps tendon is attached ; and (2) in the triceps, by a tap on its tendon above the olecranon. When excessive, and there is persis- tent contraction in the flexors of the fingers, a similar contraction can be obtained in them, or in the supinators, and even a clonus, by maintain- ing the increased tension. With the increased excitabihty of disease, a contraction can easily be obtained in the masseters by tapping the chin when the jaw is depressed, and a clonus may occasionally be produced in these muscles, and even in the trapezius. When a tendon is tapped, and its muscle contracts, the occurrence has so much the aspect of a true reflex action that it was generally assumed to be such, the stimulus being the excitation of nerves in the tendon. This view received apparent confii-mation by the discovery of certain facts. (1) That there are nerves in tendon. (2) That these phenomena depend for their occurrence on the integrity of the reflex path to, through, and from the spinal cord, and are arrested by a lesion in this path. By experiments on animals (in whom similar contractions may be obtained) it has been found that they are pre- vented by division of the nerves to the muscles, by division of either the anterior or posterior roots of the spinal nerves, or by destruction of the spinal cord.f These experimental facts are abundantly confirmed by those of * Other illustrations will be found in the writer's paper (' Med.-Chir. Trans.,' 1879), " The so-called Tendon-reflex Phenomena." Since then tracings have been published by Charcot and many others. f See Tschirjew, 'Archiv fur Psychiatrie,* Bd. viii. Heft 3, 1878, and manj subsequent investigations, among which the most important are those of Waller (• Journ. of Phys.,' 1896) and Sherrington (' Proc. Roy. Soc.,' 1893). They do not involve practical questions, such as to make their description needful here. 24 SYMPTOMS. disease, conspicuously in peripheral neuritis. They unquestionaWy show that some reflex action is essential; but (as Westphal main- tained from the first) they do not prove that the contractions depend on a simple reflex action. From the fact that the contraction is caused by a tap on the tendon, the conclusion that the contraction ■was a simple reflex effect of the stimtdation of its nerves seemed obvious, so the name " tendon-reflex " was given by Erb, and its simpHcity and correspondence with the conspicuous facts made it at once ciu-rent, and it has remained so. Yet the theory it embodied is not only erroneous, but it obscures the general relations of these phenomena, which are of great importance for the comprehension of the symptoms of disease. Hence it is necessary to explain the evidence in some detail, and the facts show, usefully, that that which is "obvious" may, as the origin of the word suggests, be a cause of stumbling. (1) The contractions occur equally when the connections of the tendon and all its nerves have been divided. (2) They occur only when the muscle is in a state of slight passive tension, and the tap on the tendon can increase this. With a relaxed muscle, a pinch of the tendon produces only a wide reflex action, like that from a pinch of the skin; indeed, this follows a pinch that can be felt when the muscle is tense. Definite stimulation of the nerves of the tendon never acts on its muscle only. (3) Not only must the tap increase the tension, but (as we have seen when these phenomena are excessive) any similar sudden increase has the same effect, e.gr. ataponthe bone to which the tendon is attached. That on the depressed patella (p. 22), has the same effect as a tap on the tendon below. When there is extreme excess, the readiness with which a tap on the bone is effective has led to the idea that the stimulus is from the periosteiun, but the tap is only effective when it can act mechanically on the muscle. It must be on the bone to which the muscle is attached, and in the direction to increase its tension. The evidence is conclusive that the contractions are not excited by stimulation of the nerves of the tendon ; the stimulus originates in the muscle, the tendon being only a means by which that stimulation is produced. If so, is not the contraction itself a reflex effect F It was suggested by two of the earliest investigators, Tschirjew and Westphal, that the contraction is local in production, due to the influence of the stimulus on the whole of the muscular fibres when they are rendered specially excitable by the reflex influence of the tension acting through the spinal cord. A reflex action takes a certain time, which is needed for the impulse to travel to and from the cord, and for the reflex process to occur ia the centre. According to received physiological data, an interval of at least one fifteenth of a second would be needed for the knee-jerk if it were a reflex process, and rather more for the movement at the ankle. I have found that when the Achilles tendon or the front of the leg is EEFLEX. 25 tapped, tlie resulting contraction occurs in about "033 sec* The interval for the knee-jerk has been found by most to be about •04 or '033 or '022 sec.f Gotch found it to be "025 sec, and that between the tap on the tendon and a true reflex contraction of the opposite quadriceps to be '11 sec.J But it is certain that some reflex process is concerned in the pheno- mena. We have still to account for the irritability which permits the local stimulus to cause a contraction. This irritability is developed by passive tension. If the muscle is relaxed, the fibres may contract if they are struck directly, just as do the fibres of a separated frog's muscle, but no contraction can be produced by striking the tendon. Hence we must assume that the tension excites, by a reflex influence, a state of irritability to local mechanical stimulation, — such as that of a tap on the muscle, on its tendon, or even the vibration from a tap on the bone or on adjacent parts. But only that form of mechanical stimulation is effective which suddenly increases the previous tension. It is only because the tap on the tendon does this so readily that the tendon is the means by which the contractions are most easily pro- duced, and through which they have been chiefly studied and pre- maturely named. If the tension put on a muscle is gentle and gradual, it may only develop the irritability, and an additional local stimulation is necessary to produce a visible contraction. If, however, the tension is sudden and forcible, it not only develops the irritability, but pro- duces visible contraction in the muscle thus rendered irritable — as in setting up the foot-clonus. I have shown that the relaxation of the muscle, between the successive contractions, is not complete : there is persistent residual contraction, i. e. a tonic contraction on which the clonic contractions occur. When one clonic contraction is over, the tension continuing, a second is instantly developed. The production of the clonus seems thus to depend on the limited dura- tion of single muscular contractions (such as are obtained by a single induction shock§), the effect of sudden tension being exerted on all the fibres of a muscle at the same time. In the state of excitability produced by the moderate tension its effect on the relaxing fibres is • ' Med.-Chir. Trans.,' 1879, p. 292. An erroneous distinction between the nnture of the knee-jerk and foot-clonus was made in this paper. t -039 sec, Burckhardt; -032— -034 sec, Tschirjew ; "04 sec. Brissaud ; -03— -04 sec, Waller; '03 sec, Eulenberg. Some of my own measureinunts ('Med.-Chir. Trans.,' 1879, p. 275) gave a longer interval when the movement of the foot was taken as the indication of' the commencing contraction. " Load " will increase greatly the period of latent stimulation, probably by causing the initial contiaction to expend itself on the elasticity of the muscle. The measurements given above were obtained by recording the commencing contraction of the muscle. J 'Journ.of Phys.,' 1896, vol. xx, p. 322. In the rabbit he found the interval for the tendon-contraction to be only "005 sec, and compares this with Tigerstedt's measurement of the interval when the nerve is stimulated ('01 sec, twice as great), and concludes that the contraction can only be direct. § See Fostei-'s ' Physiology,' 1888, pt. i, p. 78. 26 SYMPTOMS. tliat of a fresh stimulus, and they contract again. We have no facts to suggest that such serial contractions could each be produced through a reflex mechanism. We have seen that the afferent nerves of muscles are especially excited by tension (see p. 17). If there were reason to regard each contraction as reflex we should have to regard these nerves as the seat of the excitation. The facts on all relations are better explained, and some pathological facts are only explained, by the assiunption that the tension causes by reflex action this irritability. It seems, therefore, that the term "tendon-reflex" is altogether inaccurate. The phenomena are, according to the explanation above given, dependent on a " muscle-reflex " irritabihty, which has nothing to do with the tendons. If each contraction is reflex, it must be generated by an afferent impulse from the muscle-nerves, not from the tendon-nerves. This fact seems conclusive and inevitable. Hence if we wish to describe them by a general term, it is best to employ one which does not involve any special theory of their nature. They have been termed " tendon-muscular phenomena," but the intervention of tendons is not necessary for their production ; the one condition which all have in common is that passive tension is essential for their occiir- rence, and 1 have suggested* that they be termed m«/o^a.iic contractions (rnrnos, extended). The irritability on which they depend is due to and demonstrative of a muscle-reflex action which depends on the spinal cord. It is highly probable, as Tschirjew suggested, that the condition on which the myotatic irritability depends is identical with muscular "tone." Since the experiments of Heidenhain it has been generally admitted that "tone" depends on tension, and is a reflex process. t A true "tendon-reflex" may be excited by pinching the tendon, but this is a start of the whole limb, precisely such as results from a pinch of the skin. It is an instance of the pain-reflex described above. The importance of discarding the tendon-reflex theory (and therefore the name) is great, for it prevents the comprehension of the true nature of other phenomena of great importance. Chloroform first increases and then abolishes the irritabihty; in ether narcosis (except when extremely deep) it is increased : J asphyxia has a similar effect, at first increasing, then aboHshing, while oxygen simply augments the excita- * ' Diasnosis of Diseases of the Spinal Cord,' 2nd edit., 1881, p. 29. t By some interesting researches recently published, Mommsen has reached tbe same condasion, that muscular tone is dependent on a muscle-reHex action excited by tension acting on the sensory muscle-nerves (' Virchow's Archiv,' Bd. ex, p. 22). The view given above has been reremly advocated by Gotch as the result of his experiments (' .louni, of Physiology,' 1896), and is indeed now generally accepted by physioliigists. X 'Diagnosis of Diseases cf the S|iin;il Cord,' 1883, p. 31; observations hj Horsley. REFIEX. 27 bility.* Tlie relation of these contractions to the nerve-centres will be considered in connection with these. Paradoxical Muscular Contraction. — This name has been given by Westphal t to a slow tonic contraction occurring in a miascle when its attachments are suddenly brought nearer in some morbid states. It is best seen in the tibialis anticus ; if the foot is grasped, and passively flexed on the leg, the tibialis anticus contracts, sometimes after an appreciable interval ; its tendon stands out, and the contraction keeps the foot flexed for a time, which may be some minutes (in one case for twenty-seven) : the relaxation is slow. Repetition lessens the con- traction. The contraction is not voluntary (although a voluntary contraction may simulate it). It may occur on one side only. The contraction produced by brief faradism may be similarly prolonged in the same case. A similar contraction may be observed in the extensors of the toes, sometimes in the flexors of the knee, rarely in the arm muscles. It seems to be an excessive manifestation of a physiological relation by which suddenly diminished tension increases as increased tension lessens the activity of the motor centres. Tension stimulates the afferent nerves, and the relaxation of the opponents of a contracting muscle during movement seems to be thus produced, as is made probable by the absence of descent of the upper lid in palsy of the inferior rectus. J Sherrington has shown that if the nerve to a muscle is cut and its central end stimulated the opponents relax. § Con- versely we can understand that diminished tension may induce over- action. It seems to be an excess of the contraction by which a muscle adapts itseK to passive shortening of its course. Jn the cases that have presented this phenomenon there has been no muscular rigidity, and no great excess (even sometimes a loss) of the myotatic irritability. It may occur in the early stage of tabes, and in some other affections, but its &iignificance is not known. A phenomenon somewhat similar occurs in hysteria (Fere) ; it seems, indeed, but an isolated and imper- fect instance of the condition that, when universal and perfect, consti- tutes the flexihilitas cerea of catalepsy, i. e. an unrestrained spinal reflex process in the centres concerned in the states of the muscles. Changes in ISTtjtbitign. — The nutrition of all the tissue elements is largely under the influence of the nervous system. Whether this influence is exerted through special "trophic" nerves, or through the motor, the sensory, and especially through the vaso-motor nerves, is a question that has been much discussed in the past. The balance of evidence is against the existence of special trophic nerves or centres. The fact regarding these changes that is clearest and most important is • Risien Russell (' Proc. Roy. Soc.,' vol. liii, p. 430). t 'Arch. f. Psych.,' Bd. x, p. 243. X Sco the Author, * Med.-Chir. Trans./ 1879. § 'Brit. Med. Journ.,' 1893. 28 SYiirxoMS. tliat acute disturb ince of nutrition is the result of irritative changes in the nutrition of the nerves, and is in proportion to the intensity of that irritation. If a thread is passed through each sciatic nerve, and one is also irritated by the application, from time to time, of irritant liquids, trophic changes occur in that limb with greater rapidity and far greater intensity than in the other (Lewaschew). The same fact is frequently indicated by the extreme readiness with which trophic lesions of the skin, and even cellular tissue, occur in certain forms of inflammation of the spinal cord, especially in those that have a strong tendency to spread in the cord, and to the nerves, if they reach the centres of them. The only apparent explanation of the various facts is that the nerve-endings are related to the tissues in such a way that the nutrition of the molecules of the tissues is determined in its character by that of the nerves. The process of irritation descends the nerves ; it passes from them to the tissues, and extends to all that are in continuity. Thus we can understand equally the acute changes in the muscles, which will be described as resulting from disease of the motor nerves, and also those in the skin and other tissues that are under the influence of the sensory fibres. Nutritive changes in the skin are easily recognised, but they diffei much in their character according to their acuteness. When they are rapid, and due to very acute irritation of the nerves or the spinal cord, such as those just mentioned, the temperature of the limb is raised, the vessels readily dilate, and remain dilated for a long time, bullae form, containing a dark-coloured liquid, and slight pressure occasions a slough. These changes sometimes seem to occur spontaneously, but are more often excited by some cutaneous irritation, and very slight irri- tation of the skin will suffice to produce them. Trifling pressure will set up a slough, and extensive vesication may result from the applica- tion of a hot-water bottle that is not more than pleasantly warm to a healthy hand. When the nerve irritation is intense, effusion may occur into the joints. In the case of the fifth nerve, acute trophic changes occur in the eyeball, chiefly when the disease involves the Gasserian ganglion, or the nerve in front of it. To produce the same effect, a lesion behind the ganglion has to be more irritating than one in front of it, and a similar relation obtains in the case of the spinal nerves and the spinal gangha. The cells of the ganglia govern the nutrition or their processes in each direction, i. e. of the whole neuron, and we can understand that they have some power of hindering the propagation of in-itative changes, while, if these invade the ganglion, they pass thence with special energy. Very intense changes in nutrition may thus pass to the skin in acute inflammation of the spinal cord. The alterations in nutrition in chronic lesions (which have been carefully studied by Paget and Weir Mitchell) differ considerably from those that result from acute irritation. There is a slow change in the nutrition of the skin, which becomes red, thin, and shiny — the " glossy EEFLEX. 29 skin" of Paget. The subcutaneous tissue also wastes, so that the finger tips become pointed. The growth of the hair and nails is altered, and the latter become brittle. The bones may suffer in their nutrition, and may break more easily than in health. If the lesion occurs during the period of growth, this is retarded.* These changes seem to depend on slower change in the nutrition and vitality of the tissue elements corresponding to a slower change in that of the nerves, an atrophy rather than a degeneration, f The muscles suffer from lesions of the motor nerves ; the minute changes are described with the latter. At first there may be merely fiabbiness, and an appearance of wasting that is not confirmed by measurement, but there is soon an actual diminution in the circum- ference of the limb. In extreme cases all the muscular tissue dis- appears, and the contour of the limb is considerably changed. In comparing the size of the Hmbs on the two sides it should be remembered that the limbs on the right side are normally some- what larger than those on the left side, and that the difference varies according to the occupation of the individual, and the degree in which this involves a greater use of the limbs on one side. In measuring, great care is necessary to secure, as nearly as pos- sible, the same conditions on each side, both as regards the state of the muscles and the place of measurement. It is best, wherever j'ossible, to take the maximum measurement in each part, rather than to attempt to make the measurement in the same place. In the calf the maximum circumference should always be taken. In the thigh accurate measurement is extremely difficult, because a maximum cannot be taken. We may endeavour to measure at the same point in the thigh at the same distance from the condyles, but it is very diffi- cult to be exact, and a more accurate comparison can often be mada by taking the minimum circumference above the knee, in spite of the fact that the muscular tissue there is small, and the difference less than it is elsewhere. In the forearm the best result is obtained by taking the maximum measurement around the muscular prominence below the elbow, over the supinator longus. In the upper arm, the circum- ference is nearly the same in the middle third, and the measure- ment may be made halfway with little risk of error. In all cases care must be taken to draw the tape equally tight at each place. It is easier to do this with a flexible steel measure than with an ordinary tape measure. Exactness is best secured by having a spring at one extremity of the tape with an index that will show the tension. Electrical Irritability. — The nerves and muscles are excitable by electricity, and the excitability is changed by disease, of which the * But the subject of hindrance to growth is complex, and still not clear. See the account of infantile paralysis. t Cf. Maiinesco on degeneration and atrophy ("La Theorie des Neurones,** • Presse Med.,' 1895). 30 SYMPTOMS. change is often an important symptom. It indicates the state oi nutrition of the nerve-fibres and muscles, and from this we can often draw important inferences regarding the condition of the centres. In the normal state nerve-fibres are stimulated by either the induced or the voltaic current, the stimulation of the motor nerves being shown by contraction in the muscles supplied by them, that of the sensory nerves by the sensation that is caused. The contraction of the muscles is continuous when the faradic current is applied, but if the isolated shocks of which the current consists are separately passed, each causes a brief, momentary contraction. When the voltaic current is applied, contraction occurs, with a current of moderate strength, only when the strength of the current is changed, and chiefly when the current commences or ceases to pass, i. e. when the circuit is "made" or "broken." The stimulation of the sensory nerves is greatest at those times, but occurs also, in a slighter degree, during the whole time that the voltaic cui-rent is passing. Hence this is probably the case also in the motor nerves, although the stimulation is too feeble to produce a contraction in health with a strength of current that can be borne. In proportion as the nutrition of the nerve-fibres is impaired, their excitability is lowered, and a stronger current of each kind is required to excite them and cause contraction in the muscles they supply. When their nutrition is much impaired — i. e. when the fibres are "degenerated" — no contraction can be obtained even with the strongest currents. The changes in the excitability of the muscles are less simple, because in them there are two excitable structures — ^the terminal branches of the nerves, and the muscular fibres themselves. Of these the nerve- fibres are the more sensitive to faradism, and the faradic stimula- tion of a muscle, under normal circumstances, is by means of these motor nerve-endings. Thus we find that its excitability corresponds in degree to that of the motor nerve supplying it. The muscular fibres themselves are, even in the normal state, less sensitive to faradism than the nerve, apparently because they are incapable of ready response to a stimulus so very short in duration as are the shocks of which the faradic " current " consists. The proof of this consists in the fact that under the influence of curara, which removes the excitability of the terminations of the motor nerves, the muscle requkes a stronger faradic cm-rent to stimulate it than in the normal state. But under the influence of curara, or when the nerve is degenerated, the slowly inter- rupted voltaic current stimulates the muscle as readily as in the normal state ; a contraction occurs when the circuit is completed or broken — slower than that which occurs when the nerve-fibres are intact, and due to the stimulation of the protoplasm of the muscular fibres them- selves. The fact that, under normal circumstances, the contraction which is caused by the voltaic current is as quick as that produced by the faradic shock, is ground for believing that, in health, the voltaic as well as the faradic current causes the muscle to contract by exciting REFLEX. 81 the motor nerve-endings. When the motor nerve is degenerated, and will not respond to faradic or voltaic stimulation, the application of the former to the xauscle ceases to cause contraction. Apparently, the nerve-degeneration is accompanied by changes in the nutrition of the muscular fibre, by which any power of response to faradism, which it possessed in the normal state, is lost. But not only does the response to the voltaic current remain ; it becomes more ready than in health, doubtless in consequence of nutritive changes just mentioned. More- over there may often be observed a change in the readiness of response to the two poles of the voltaic current — a "qualitative " change, as it is termed. In health, the first contraction to occur, on gradually increasing the strength of the current, is at the negative pole when the circuit is closed, and a stronger current is required before closure- contraction occurs at the positive pole. But, in the morbid state we are considering, closure-contraction may occur at the positive pole as readily as at the negative, or even more readily, — and contractions, when the circuit is broken, occur far more readily than in the normal state. This condition, then — ^faradic irritability lost, voltaic irritability increased and often changed in quality — is termed the " degenerative reaction," because it occurs when the nerve-fibres are degenerated ; if we test them we shall find no response to any stimulus, voltaic or faradic. It thus indicates loss of excitability in the motor nerves within the muscles, or a change in their endings on the fibres, by which these cannot be excited, either by electricity or by nerve-impulses, in the fibres. It occurs when the latter has been produced by some toxic agent, or the fibres also are degenerated in consequence of their damage between the muscle and the ganglion cells of the cord of which they are part, or destruction of the cells. But the motor nerve-celis and fibres often undergo changes in nutrition of a much more chronic character. In this condition the excitability of the fibres is lessened gradually and slowly. The irrita- bility of the intra-muscular nerve-endings is lowered in the same degree as that of the nerve-trunks, and we have a similar diminution to both faradism and voltaism. The nutrition of the musciJar fibres is slowly, gradually impaired; and when the nerve-fibres are much affected the muscular fibres are also There is no stage in which the nerve-fibre excitability is lost, and the muscle-fibre excitability retained ; hence there is no condition of lost faradic and increased voltaic excitability such as characterises the degenerative reaction just described. Excitability is changed to the one form of stimulus just as to the other. Between these two forms there are intermedia.te conditions. For instance, the nerves may present normal irritability, while in the muscle there is often increased voltaic excitability and a changed order of polar reaction. In these cases some nerve-fibres are degene- rated, and lead to the increased excitability of some muscular fibres. In both nerve and muscle the character of the reaction is manifested 32 SYMPTOMS. by the more excitable structures ; hence it is normal in the nerve and altered in the muscle — this has been termed by Erb the " middle form of degenerative reaction," It is more accurate to call it the " mixed form." Another common intermediate form is due to the degeneration of the nerves, although slow, being less slow than in the condition described above. Hence the nutrition of the muscular tissue and its excitability (by voltaism) persist longer than those of the nerves, and although lowered, are diminished less than the faradic excitability of the nerves at each stage. When the latter is lost, voltaism will still cause a slight contraction in the muscles, which may occur first at the anode instead of the cathode. Every gradation, moreover, is met with between this and the true reaction of degeneration. This will be intelligible on consideration. It depends chiefly on the rate at which the nerves degenerate. The lowered excitability of the nerves, due to degeneration, is often preceded by a slight increase of irritability, very transient when the degeneration is acute, of longer duration when the degeneration is of the slower variety j ust noticed. In some morbid states, again, in which the change of nutrition in the cells and fibres is extremely shght, a.n increase may alone be discovered. I have found such an increase, for instance, in diseases regarded as functional, as paralysis agitans and chorea, and it is an interesting proof of the molecular changes which underlie, or result from, so-called " functional " maladies. The various changes in irritability were formerly thought to indicate the existence, and various affection, of separate centres for the nutri- tion of the nerves and muscles, apart from, though acting through, the motor nerve-cells. Remembering that the fibres of the nerves and muscles suffer in different degrees, as above described, the phenomena may all be explained on the simpler principle stated, without the assumption of these special centres, of the existence of which there is, indeed, no evidence. Special trophic nerves and centres for muscular nutrition have quietly disappeared from physiology, and are now only matters of interest to the student of its history, and to those whose memories reach further than two decades. It is, however, important to remember that such alterations in nutrition and excitability as occur in the whole course of the motor fibres when the cells are affected (of which they are the prolonged processes) may have a different origin at the periphery. They are the same in "degenerative peripheral neuritis," which begins in the extremities of the fibres (where vital resistance is least in consequence of distance from the cell body), and extend for a variable distance upwards. But this condition is seldom, if ever, so slow as to permit the equal loss of nerve and muscle excitability met with in the central degenerations. MUSCLES OF UPPER LIMB. 88 THE MUSGLE8: THEIE ACTION AND PABALY8I8, Disease of the motor nervous system is largely manifested by loss of muscular action. Individual muscles, as well as groups of muscles, are often separately affected. Hence it is desirable to consider the symptoms of the paralysis of the more important muscles, before we enter on the study of special diseases. The symptom of the palsy of any muscle is a loss of its normal action, and a knowledge of this action is essential for the comprehen- sion of those symptoms. The two must therefore be considered together. They are positive and negative aspects of the same facts. It may be well, at the same time, to mention the nerve by which each muscle is supplied, and also the spinal roots from which the fibres come. These cannot be ascertained by dissection. Of the several roots that join to form the cord of the plexus from which the nerves to two muscles come, fibres from all may pass iato one nerve, and from only one or two of the roots into another. The facts have been learned from experiment and the effects of disease and iajury. Their practical importance is great. The action of muscles is threefold. (1) By their tonic contraction they maintain the parts in a certain posture, independently of volun- tary effort. By actual contraction they (2) produce certain move- ments, and also (3) oppose the action of other muscles by a feebler contraction, and thus steady the movement that results. The complex way in which muscles act together, and modify each other's effect, renders the subject a very large one. Here only an outHne can be given of the more salient facts concerning the most important muscles. The reader who desires to pursue the subject further can do so ia the ' Physiologic des Mouvements ' of Duchenne, whose investigations by means of faradism and his observations on disease were so careful and so extensive as to leave little but confirmation to subsequent workers. In the following account the nerve that gives the branch to the muscle is first given, and then the number of the nerve-root or roots — (C)ervical, (D)orsal, or (L)umbar — from which the nerve-fibres come. Special Thoeacic Muscles. The DiAPHEAGM (C. 4 chiefly, phrenic nerves), although a double muscle with Wo nerves, habitually acts as a whole, the two halves contracting simultaneously and diminishing each lateral curve of the arch. The central tendon descends but little. The abdominal viscera are depressed, and the parietes protmded. If the hand is placed beneath the ribs, the descent of the viscera beneath the diaphragm can be felt. When the diaphragm contracts alone, as when the intercostals are paralysed, or the phrenic nerve is faradised, the ribs to which VOL. I. 3 34 ACTION AND PAEALTSIS OF MUSCLES. the muscle is attached are slightly raised during its action, and this elevation causes a slight expansion of the thorax. In ordinary breathing this expansion is lost in the action of the intercostals. In paralysis the inspiratory protmsion of the upper part of the abdomen is lost ; it even recedes during inspiration instead of advancing, and a descent of the viscera can no longer be felt by the hand. There often results an alternation in the respiratory movements of the thorax and abdomen, retraction of the one corresponding to protrusion of the other. Steeno-MASToid (spinal accessory nei've C. 2 — 5 or 6, also branches from upper tervlcal plexus), passing from the sternum and adjacent part of the clavicle to the mastoid process, inclines the head towards, and rotates the face from, the side on which the muscle contracts. Both muscles together support the head in the vertical position, and if it is bent back, they bring it forwards into, but not beyond this position. Paralysis of one muscle has no influence on the position of the head, and but little on its movements. Other muscles supplement the loss. There is no such thing as a " paralytic torticollis." In palsy of both muscles the head can be balanced in the vertical position, but if it falls back it can be brought forward only with great difficulty. Each sterno-mastoid is associated in action with the muscles of the other side ; it is a " contra-lateral muscle." For instance, in using the right arm, the head is tui'ned to the right by the left sterno-mastoid. This association is sometimes reproduced in disease. Mtjscles moving the TTppee Limbs. Muscles moving the Scapula and Shoxjldee-joint. — The Trapezius spinal accessory (C. 2 to 6, whether also the lowest C. and upper D. is doubtful)* consists of three parts. The first, from the occipital bone to the outer end of the clavicle, is rarely used except in breathing (respiratory portion — ^Duchenne). Fig. 5. — Paralysis and wasting of tra- pezius ; alteration in contour of shoulder at rest. Pig. 6. — Ditto when the arms are raised (the right one being aided by another person). The second part is that which passes from the lig. nuchae, lowest cervical, and upper three dorsal spines, downwards and outwards to the acromion and outer * Anatomists now believe that the twigs from these nerves only pass through the muscle, and tliat it is wholly supplied by the spinal accessory. This agrees with the fact that its artion is chiefly with the arm. MUSCLES OF UPPEE LIMB. 85 part of tlio Bpine of the scapula. The lowest part passes from the dorsal spines below the third, outwards and partly upwards, to the inner half and base of the spine of the scapula. The second part is the chief elevator of the scapula and shoulder. With the third part it brings the scapula towards the spine, and puts the shoulder back. Both parts tend to rotate the scapula — acromion up, lower angle out. By this rotation the arm is carried above the horizontal level to which the deltoid raises it. Paralysis of the highest pai-t has little influence on the movement of the scapula, but causes a change in the contour of the neck (Fig. 5) especially conspicuous on deep inspiration. The change in the shape of the neck is very great, when the arms are raised, if the whole trapezius is wasted (Fig. 6). In palsy of the middle part the elevation of the shoulder is imperfect ; in that of the third part the scapula is farther from the spine than normal. In palsy of all parts the scapula becomes rotated (acromion down, infeiior angle in) by the weight of the arm and the contraction of the opponents (Fig. 7). The rotation may mask the displacement outwards, due to the paralysis of the lowest part. If the clavicular part remains, there may bo no rotation, but the scapula is lower than normal. The Rhomboids (a nerve that passes through the scalenus — C. 4 and 5) first rotate the scapula on the outer angle, moving the lower angle inwards, and then move the whole scapula upwards and inwards. In strong elevation they aid the trapezius, which prevents the rotation of the scapula. The rotatory action aids forcible depression of the raised arm. The muscles also fix the scapula for the action of the teres major. Their tone helps to keep the scapula against the thorax (opposing the pectoralis) and in its vertical position (opposing the serratus), and hence, in paralysis, the edge of the scapula, at rest, Yia, 7. Paralysis and stands out a little, leaving a furrow, and the scapula is wasting of deltoid and slightly rotated (lower angle out). Movement is but little interfered with by the paralysis of the rhomboids; but the movement backwards of the raised arm by the teres and deltoid is feeble for want of the fixation of the scapula. The Levator anguU scapulae (direct branches from C. 3 and 4 or 5) first rotates the scapula on the outer angle and then raises it. The muscle is usually paralysed with the trapezius, and then the scapula falls, but the special effect of its palsy is lost in that of the trapezius. If the levator is preserved, and the trapezius paralysed, there is great rotation of the scapula, which is, as it were, suspended by its inner angle (Fig. 7). Serratus magnus (posterior thoracic nerve — C. 5 and 6) carries the scapula outwards, forwards, and slightly upwards when the arm is put forwards. It tends to rotate the scapula on the inner angle (acromion up), the lower fibres most powerfully, hut this rotation is prevented by the rhomboids and levator anguli. It does not raise the shoulder when the arm is hanging. It helps to fix the scapula when the posterior fibres of the deltoid move the raised arm back. If the scapula is fixed by the rhomboids, the serratus can act on the ribs, and aid foi'ced inspiration. It has most inspiratory effect when the arms are elevated. In paralysis there may be little change in the position of the trapezius ; rotation of scapula, from weight of arm, in consequence of the paralysis of the tra- pezius; progressive mui« cnlar atrophy. 36 ACTION AND PARALYSIS OF MUSCLES. scapula at rest, but often there is slight rotation (lower angle in) from the unopposed tone of the rhomboids. When the arm is moved forwards by the anterior part of the deltoid, the scapula, no longer held against the thorax and moved forwards by the serratus, is rotated on its vertical axis by the action of the anterior part of the deltoid on the humerus, and of the middle part on the scapula. Thus the posterior edge recedes from the thorax, leaving a groove into which the hand can sometimes be placed (Fig. 8). The scapula is at the same time rotated, lower angle inwards and upwards. Elevation of the arm above the level of the shoulder is much weakened, but can be imperfectly effected by the middle part of the trapezius. Loss of the serratus weakens other movements, but does not abolish any. Inspiratory expansion of the thorax, when the arms are raised, is distinctly less on the paralysed side (Poore). Fig. 8.— Paralysis of the serratus magnus ; FiG. 9.— Paralysis of right deltoid; ele^ eversion and rot;ition of scapula when vatiou of shoulder by trapezius on an the arm is put forwards. attempt to raise the arm, which is slightly abducted by the supraspiuatus. The Deltoid (circumflex nerve, from the brachial plexus posterior cord — C. 4 and 5) abducts the humerus, the anterior and posterior fibres also moving the arm forwai-ds and backwards respectively. The arm is raised least by the posterior, and most by the anterior fibres, but even the latter only elevate it to a right angle with the trunk. Hence, if raised by the anterior fibres, and then moved back by the posterior, it is at the same time depressed. Elevation above a right angle is by rotation of the scapula (trapezius and serratus). These muscles also fix the scapula for the deltoid, preventing the rotation (acromion down, lower angle in) that the deltoid acting alone would cause. In paralysis, abduction of the arm, direct, forwards, and backwards, is almost lost. All the abduction that remains is a trifling movement by the supraspinatus. An attempt to abduct results in rotation of the scapula and elevation of the shoulder (Fig. 9) from an excessive innervation of tlie associated trapezius and serratus, which, as we have seen, fix the scapula when the deltoid acts. Para- lysis of single parts of the deltoid causes loss of the corresponding movements of the arm, but if the middle part only is paralysed, there is still a limited MUSCLES OF UPPER LIMB. 37 power of direct abduction by tbe conjoined contraction of tbe anterior and posterior parts, aided by the supraspinatus. The Supraspinatus (suprascapular nerve — C. 4 and 5) ahducta the arm, moves it forwards, and rotates it in. It thus aids the deltoid. Isolated para- lysis of the supraspinatus has little influence on movement or position ; but if the deltoid is also paralysed, the head of the humerus falls away from the acromion far more than when the deltoid is paralysed alone. The Jn/raspinaitts (suprascapular nerve— C. 4 and 5) rotates the humerus outwards, and in paralysis this movement is lost. A diflaculty in writing is produced, the movement along the line being by this rotation of the humeras. The Teres minor (cii'cumflex nerve — C. 5) has a similar action to the infra- spinatus, and its palsy has a similar effect. The Subscapularis {short subscapular nerve, from the fifth and sixth cervical) rotates the humerus in, and its paralysis lessens this movement. The Latissimus dorsi (long subscapular nerve, from the brachial plexns, posterior cord — C. 7) lowers the raised arm, and puts it back; the upper pai-t adducts the scapula, the lower depresses the shoulder by acting on the humeras, which it tends to drag out of the socket. It inclines the trunk a little, and both muscles together extend the trunk. In paralysis, forcible backward depression of the raised arm is lost, and the shoulder cannot be put back without being also raised (by the trapezius). The Pectoralis major (anterior thoracic nerves from the brachial plexus, outer and inner cords — C. 5, 6, and 7) consists of two muscles, the action of the clavicular and sternal parts being different. The clavicular (which arises also from the highest part of the steinum), if the arm is hanging, brings the shoulder forwards and upwards, as if shivering; if the arm is raised, it is brought forwai-ds and lowered to the horizontal position. The muscle is thus concerned, Duchenne says, in the "cut " of the swordsman and the benediction of the priest. The sternal portion lowers the raised arm from every position, and if the arm is hanging, it draws the shoulder down. Paralysis of the upper part has little effect on the movement of the arm, because the anterior fibres of the deltoid have the same action. It is easily recognised by making the patient put his arms in front of him and press the palms together. In paralysis of the lower part, even with the latissimus, the raised arm can still be lowered accu- rately by the weight of the arm and relaxation of the elevators, but it cannot be lowered against even a slight resistance. Thus a blacksmith with this defect could wield a heavy hammer, but could not blow the bellows by pulling down- wards a cord (Duchenne). The Teres major (short subscapular nerve from the brachial plexus posterior cord — C. 7) appi'oximates the humeras and the outer edge of the scapula, by bringing the former to the side of the trunk, and rotating the lattei-. The simultaneous contraction of the levator anguli and rhomboids, fixing the mner angle, causes this rotation to raise the prominence of the shoulder. Hence, in a forcible elevation of the shoulder, the arm is pressed against the side, the lower fibres of the latissimus and pectoralis major aiding the adduction. The teres cannot alone put the arm behind the trunk. In paralysis, the eleva- tion of the shoulder, with the arm against the side, is lost. Muscles moving the Foeeaem. — Triceps (musculo-spiral nerve — C. 6 and 7). — The long head has an action similar to the teres, but feebler. It contracts when the arm is forcibly lowered, and prevents the displacement downwards of the head of the humerus by the actual depressors, the latissimus and pectoralis. All parts extend the elbow, the long head with less force than the others, but its 38 ACTION AND PAKALTSIS 0¥ MUSCLES. action on the shoulder-joint, just mentioned, ia important, because forcible depression of the raised arm is often associated with extension of the elbow. In paralysis of the triceps the elbow can only be extended by the weight of the fore- arm, and extension against gravitation is impossible. Thus a man with paralysis of the triceps cannot raise his hat in the customary manner. Flexion of the elbow is uncertain, on account of the loss of the antagonistic steadying force. The Brachialis anticus (musculo-cutaneous and musculo-spiral nerves) flexes Triceps (long head) — Triceps (inner head) Ulnar n. < Flex, carpi ulnar. Flex. dig. profund. Flex.dig. sub. (ir& III) Flex, digit, sub. (I &IV) Ulnar n. Palm brev, Abd. niiniiu. digit. Flex. min. aitr. Oppon. min. dig. Lumbricales Deltoid (ant. half) Mus.-cut. n. Biceps Brach. ant. > Median n. Supinator long. Pronator teres Flexor carpi radialis Flex, digitor sublim. Flex. long, pollicis Median n. Adductor pollicis Opponens pollicis Flex. brev. pollicis Adductor pollicis Fig. 10. — Motor points for the arm, inner side (from Erb). The points at which the nmsfles :iiid nervps can most effectively be stimulated. MUSCLES OP UPPER LIMB, 39 the elbow simply. Its rare isolated palsy has little effect, since it is supple- mented by the biceps and supinator longus. The Biceps (musculo-cutaneous nerve — C. 4, 5, and 6) supinates the forearm if it is pronated, and then flexes the elbow. In paralysis the flexion can still be effected, but the traction on the humerus causes pain at the shoulder, from the loss of the support of the long head of the biceps. The Supinator longus (musculo-spiral nerve — C. 4 and 5) places the forearm midway between pronation and supination, and then flexes the elbow. If it is paralysed there is a tendency for supination to accompany flexion (biceps) ; and if the brachialis anticus is also paralysed, the elbow can only be flexed when the foreann is supinated. If the three direct flexors of the elbow are paralysed, feeble flexion is still possible by the extensors of the wrist, which cross the elbow-joint, but only after the forearm has been pronated and the wrist over-extended. Deltoid (posterior half) Muse. -spiral n. Brachialis ant. Supiuator longus Extensor radial, long. Extensor radial, brev. Extensor digit. -I Extensor indicis Ext. OS. met. pel. Extensor pr. intern, pol. Dorsal interossei J (I and II) 1 Triceps (long Lead) Triceps (outer head) Extensor carpi uln. Supinat. brev. Extens. minim, digiti Extensor indicis Extens. long. poll. Abduct, minim, digiti } Dorsal interossi^i (III and IV) Fig. 11. — Motor points for the wrm, outer side (Erb), 40 ACTION AND PARALYSIS OF MUSCLES. The Supinator hrevis (musculo-spiral nerve by posterior interosseous branch— C. 5) is the only simple supinator. If it is paralysed, supination can still be efEected by the biceps, and also by the supinator longus as far as midw^ay between pronation and supination. Pronators. — The p. teres and p. quadratus (median nerve — C. 6 and 7) both pronate strongly, and their palsy causes loss of this movement, but pronation to the mid-position is still possible by the supinator longus. Muscles moving the Hand. — Flexors of Wrist. — The F. carpi ulnaris (ulnar nerve) and F. carpi radialis (median — C. 7 and 8) flex the wrist. The ulnar flexor tends to turn the supinated hand still more out, but neitlier moves the wrist-joint laterally. Flexion indeed hinders the lateral movements of the wrist, in consequence of the shape of the articular surfaces. The f. c. ulnaris flexes the fifth metacai-pal bone on the carpus as well as the wrist-joint. In paralysis, flexion of the wrist can only be effected by the flexors of the fingers when these are extended. Extension of the wrist is unsteady from the loss of the antergic contraction of the flexors (see p. 10). Extensors of Wrist. — Extensor carpi radialis hrevis et longus ; E. c. ulnaris (musculo-spiral nerve and its posterior interosseous branch — C. 6 and 7). The short radial is a direct extensor ; the long radial and the ulnar move the hand laterally as well. In para- lysis of all thi-ee extensors the wrist can only bo extended by the extensors of the fingers when the phalanges are flexed. In loss of the short radial, direct extension is still possible by the long radial and ulnai', and lateral extension by one of these alone. If either is paralysed, together with the short radial, direct extension is lost, and only lateral extension, in the direction of the remaining muscle, is possible. Pai'alysis of either lateral extensor, long radial or ulnar, leads to permanent deviation of the wrist in the direction of the remaining muscle (Fig. 12). Pig. 12. Paralysis of The loss of the long radial is more serious than the long radial ex- that of the ulnar, because the radial lateral move- tensor of the wnst in a ixient is of more importance, being needed for the dSon'S'thf hS convenient motion of the hand to the mouth. Para- towards the ulnar side. lysis of the extensor impairs flexion of the fingera, (After Duchenue.) from the great shortening of the course of the ten- dons by the flexion of the wrist that occurs. The ulnar extensoi* acts also synergically with the extensor of the metacarpal bone of the thumb, as may be noted if the finger is placed on the tendon beneath the styloid process of the ulna. Hence, in paralysis of this extensor, the hand deviates laterally when the thumb is strongly extended. Extensors of the Fingers. — Extensor communis digitorum ; E. indicis ; E. minimi digiti (musculo-spiral nerve — C. 6 and 7). The common extensor moves the fingers and then the wrist. When the muscle is faradised, the extension begins at the distal phalanges, and these become flexed again, when the hand is extended beyond the plane of the forearm, by the tonic force of the flexors, the course of their tendons being elongated by the extension of the wrist. Moi'eover the muscle has little action on the last two phalanges, since they cannot be extended by the long extensor, if the interossei, their proper extensors, are paralysed. During extension by the communis the fingers are separated from the second. The extensors of the first and last fingers have a similar MUSCLES OP UPPER LIMB. 41 extensor action, but, in addition, they adduct their respective fingers towards the middle finger. In paralysis, the extension of the fingers is impossible; but if the proximal phalanges are passively extended, the middle and distal joints can be extended by the interossei. For the lateral movements of the digits, exten- Bion of the proximal phalanges is essential, and hence these movements are lost, but they can be performed if the proximal phalanges are passively extended. The posture of the fingers due to contraction of the palmar fascia resembles that in palsy of the long extensor (see Fig. 13), but an examination of the palm shows the cause of the flexion. Flexors of Fingers. — F. sublimis (median nerve — all fibres C 7 and 8) ; F. profundus (median and ulnar nerves). These muscles flex chiefly the second and third phalanges, the first phalanx being flexed by the interossei. The superficial muscle flexes the second phalanx on the first, the deep flexes both. The action on the first phalanx is confined to extreme flexion of the fingers, and is the less, the more the wrist is flexed. But if the flexion of the middle and distal phalanges is prevented the first is strongly flexed. In extreme shortening of the course of the tendons by flexion of the wrist, the action on the fingers is very feeble, evidence of a normal antergic action of the extensors of the wrist. Fig. 13 Fig. 14. Fig. 13. — Posture of the hand in contraction of the palmar fascia, resembling that in paralysis of the long extensors of the finger. Fig. 14. — Paralysis of the fibres of the flexor sublimis which act on the two middle fingers : twelve years' duration. The second phalanges of these fingers are bent backwards and subluxated from the contracture of the unopposed interossei, while the last plialanges are kept in position by the unaffected flexor profundus. (After Duchenne.) When the extensor of the fingers is in strong action, extending the proximal phalanges, the action of the flexors on the second and third joints is very strong (tearing position). In paralysis of these muscles the power of flexing the last two joints is lost, but the interossei still flex the metacarpo-phalangeal joints. Paralysis of the deep flexor alone causes merely loss of the power of flexing the distal joint, but this impairs many movements, such as playing on the piano. In paralysis of these muscles, the unopposed tone of their opponents, the interossei, which extend these joints, leads in time to over extension, and, with repeated passive pressure in using the fingers, may even produce a sub- luxation backwards. In palsy of the sublimis this effect is chiefly seen at the middle joint (Fig. 14), in that of the profundus at the distal joint. Interossei and Lumhricales (ulnar nerve, except the outer two lurabricales, which are supplied by the median — C. 8 and D. 1). — The interossei abduct and 42 ACTION AND PARALYSIS 0^ MUSCLES. adduct the fingers, but only when these are extended at the metacarpo« phalangeal joints, and some effort is required for adduction, since the tendency of the long extensor is to separate the fingers, and this influence has to be overcome. They also extend the second and third phalanges on the first, and flex the first on the metacarpal bones. The lumbricales aid the flexor-extensor action of the interossei, but do not move the fingers laterally. The opposite action of the forearm muscles and of the interosseous extensors and flexors is veiy important. Their synergic action steadies movements, and in many actions they contract alternately. Thus in making a down-stroke with a pen or pencil the long flexors bend the last two joints ; while in making an up-stroke these are extended, and the metacarpo-phalangeal joint is flexed, by the interossei. In paralysis of these muscles the lateral movements are lost, but a slight abduction and adduction of the index can still be effected by its long extensors. Only the first phalanx can be extended, and flexion is almost confined to the last two phalanges. The first two lumbricales, being supplied by the median nerve, often escape when the other muscles are paralysed by an injury to the ulnar nerve, and they aid the others when these are merely weak; hence the index and middle fingers seem to recover before the others (Fig. 15). The position of Fia. 15. Fia. 16. Fig. 15. — Recent incomplete paralvsis of the interossei from a punctured wound of the uluiir nerve at the wrist: iittempt to extend fingers. The loss of extension of the last two phalanges is cliieHy marked in the third and fourth fingers, from the influence of the lumbricales (supplied by the median) on the others. (After Duclienne.) Pig. 16. — P.iral\sis of the interossei (ulnar uerve) slight in degree: attitude of fingers at rest. the hand at rest becomes altered. Normally there is slight flexion at all joints by the tone of the muscles, interossei and long flexors. In paralysis the first phalanx is in a line with the metacarpal bones, while the other phalanges are flexed, the middle more than the distal (Fig. 16). In action this flexion is always increased, the metacarpo-phalangeal joints become over-extended, and the other joints strongly flexed (Fig. 17). Gradually the hand assumes this posture even at rest (Fig. 18), and ultimately the posture becomes warped into a deformity by the over-extension of the first phalanges, and extreme flexion oE the others, due to the contracture of the long extensor and of the flexors; the tendons of tliese muscles stand out conspicuously on the back and in the palm, and a claw-like attitude is developed, the " main en gi'iffe " (Figs. 19 and 20). Changes in the articulations may ultimately limit even passive movement. Muscles of the Thumb — Extensor secundi internodii pollicis (musculo- Bpiral nerve, posterior interosseous branch— C. 8 and D. 1) extends both phalanges, and moves the whole thumb backwards and from the fingers, so as to bring it behind the plane of the metacarpus. It may ultimately extend the wrist-joint, but it never supinates. It is not used in extending the thumb when MUSCLES OP UPPER LIMB. 43 this is opposed to the first finger. In paralysis, the metacarpal hone of the thumb is slightly flexed on the carpus, and is inclined forwards. The second phalanx is flexed on the first, and can only be extended (by the abductor and outer part of the short flexor) when the metacarpal bone is adducted and the fii-st phalanx is flexed. The constant flexion of the second phalanx interferes with the movement of the index finger, unless the patient remembers to move the thumb out of the way by the extensor of the metacarpal bone. Writing is not interfered with because the muscle i8 not concerned in extension with opposition. Fiff. 17 Fia. 18. Fia. 19. Fig. 20. PiO. 17. — Attempt to unbutton waistcoat by the hand shown in the last figure ; extreme flexion of the last two phalanges, and extension of the first, on the attempt to use the fingers. (From nature.) Fig. 18.— Old-standing palsy of interossei and thenar muscles, showing the over-extension of the first and flexion of the last two phalanges. Fig. 19. — Paralysis of all the intrinsic muscles of the hand and of the long flexor of the thumb, in conseqtience of an injury to the brachial plexus in dis- location of tlie shoulder. Tlie fingers present the claw-like attitude j the thumb is in extension. (After Duchenne.) Fig, 20. — Piiralysis of the ulnar nerve from a wound at the wrist (indicated in the figure). Extreme daw-like hand from the unopposed contraction of the coimnon extensor and long flexors of the fingers and thumb. (After Duchenne.) The Extensor primi internodii pollicis (musculo-spiral nerve, post-inteross. branch — C. 8 and D. 1) is the true abductor of the thumb. It moves the metacarpal bone outwards, and extends the first phalanx. It would move the whole hand in the same direction as the thumb, were not this tendency counter- acted by the anteigic contraction of the extensor carpi ulnaris (q. v.). It does notpronate or supinate. In paralysis abduction of the metacarpal bone is less than normal. There is an undue flexion of the firat phalanx, and the meta- carpal bone is flexed on the carpus, so that the, thumb is drawn towards the palm. The loss of this muscle is, however, compensated to a considerable extent by other muscles. 44 ACTION AND PARALYSIS OF MUSCLES. The Extensor ossis metacarpi pollicis (musculo-spiral nerve, post-inteross. branch— C. 8 and D. 1) is really the long abductor o£ the thumb. It moves the metacarpal bone outwards and forwards, flexing it on the carpus, and then flexes the wrist with slight pronation. It thus moves the thumb as much forwards as outwards. In paralysis the metacarpal bone is, at rest, less inclined forwards than noi'mal, and somewhat abducted, but the first phalanx is in its normal position. Movement of the thumb is but little interfered with. In combined palsy of the extensors of the first phalanx and of the metacarpal bone the thumb becomes adducted, and is parallel to the radius. The first phalanx is slightly flexed by the tlienar muscles. The Thenar muscles constitute two groups: (1) The short abductor and outer portion of the short flexor (median nerve — 0. 8 and D. 1) move the metacarpal bone forwards and inwards (flexing the first phalanx), incline it outwards, and rotate it inwards, so as to place its palmar aspect opposite the fingers. The second phalanx is ultimately extended. If the metacarpal bone is previously abducted the movement is greatei", and amounts to circumduction. (2) The adductor and inner part of short flexor (ulnar nerve — 0. 8 and D. 1) go to the inner side of the first phalanx. The metacarpal bone is moved towards that of the second finger: if previously flexed, it is extended; if pre- viously opposed to the index, it is moved a little outwards. The phalanges follow the movements of the metacarpal bone, but the flrst is slightly flexed and the second is extended, as the fingers are by the interossei. The Opponens pollicis (median nerve — C. 8 and D. 1) flexes the metacarpal bone on the carpus, and abducts it, but this movement is insuflScient to oppose the thumb to the index ; the conjoint action of the abductor is necessary (see above). Fia. 21. Fia.22. Fia. 23. Fig. 21. — Normal position of the thumb (for compprison with the succeeding '' figures). Fig. 22. — Position of the hand in long-standing paralysis and wasting of the thenar muscles. Under the influence of the long extensDr the metacarpal bone 01 the thumb has been brought into the same position as the other metacarpal bones, being rotated slightly, so that tlie bac-k of the thumb is in the plane of the back of the hand, like the hand of .tlie ape. (After Duchenne.) Fig. 23, from another case, shows the same condition, but still greater dis- placement of the metacarpal bone has taken place, from the greater contraction of the extensor. (After Duchenne.) The Flexor longus pollicis (median nerve — C. 7 and 8, and D. 1) flexes the second phalanx forcibly and the first feebly. It has no action on the metacarpal bone. It is used in writing (malting a stroke towards the body) and in picking up a small object, &c. In paralysis this flexion is lost, and with it these actions ; if an object is held between the tips of the thumb and forefinger, the last MUSCLES OP LOWER LIMB. phalanx of the thumh is bent back. Other movements of the thumb are not interfered with. If all the thenar muscles are paralysed the metacarpal bone is in the plane of the index, and drawn towards it by the extensor of the second phalanx, which moves the metacarpal bone inwards and backwards. The whole thumb corre- sponds with the metacarpal bone in position, the phalanges being normal. In paralysis oE the short abductor and flexor the second phalanx canaot be extended unless the metacarpal bone is abducted. These short muscles normally prevent the abduction that the extensor of the second phalanx tends to produce. The latter, moreover, prevents undue adduction when the special abductors are paralysed, but brings the metacarpal bone into the plane of the index. Thus the posture of the hand at rest resembles that of the hand of an ape (Figs. 21 and 22). If the abductor and opponens are paralysed, the tips of the thumb and fingers can only be brought together by flexing the last phalanges of the digits (Fig. 24). Then the thumb can be brought into contact with the finger by means of the short flexor, which inclines the metacai-pal bone sufficiently to effect this, although not enough for the tip of the first finger to touch the thumb when its phalanges are extended. If the short flexor is paralysed, the thumb can still be opposed ,to the first two fingei-s by the abductor, but it cannot be opposed to the last two fingers on account of the defi- cient lateral inclination of the thumb, which should be produced by this muscle. Writing is easy by means of the short abditctor, whereas if this is lost, although the tliurab can be opposed to each of the fingers, writing is much interfered with. If all the thenar muscles are paralysed, a certain amount of opposition of the thumb and fingers is still possible, by means of the flexion of the last phalanges of the thumb and fingers. If all are paralysed except the adductor, objects can still be held between the thumb and side of the palm. Fis. 24. — Paralysis of the ab- ductor brevis and opponens poUicis. From the waut of these muscles the thumb can only . be brought in contact with the tip of the index by strong flexion of the last two phalanges of the fingers, other- wise the tip of the thumb only reaches the middle of the second phalanx. (After Duchenne.) Muscles . op the Lowee Limb. Muscles moving the Hip-joint. — The Gluteus maximus (inferior gluteal nerve, small sciatic, and a special branch from sacral plexus — L. 4 and 5, S. 1) extends the hip-joint, and freely rotates the thigh outwards. It is the most powerful extensor of the hip, and it is chiefly used when a forcible extension is required, and the joint has been previously flexed. It is employed, not in standing, or in walking on level ground, but in going upstairs, or uphill, and in rising from a seat. When it is paralysed these movements are difficult. The Gluteus medius (gluteal nerve— L. 4 and 5, S. 1) is the chief abductor. All parts of the muscle have this action, but in addition the anterior third 46 ACTION AND PAEALTSIS OP MUSCLES. moves the thigh forwards and rotates it inwards, while the posterior third moves it backwards and rotates outwards. The successive action of the several parts causes circumduction. The Gluteus minimus (gluteal nerve) has pro- bably the same action. In paralysis, abduction and circumduction are lost; in Crural n. Adductor mag. Adductor long: Tens T vagiiiEe femovi«, Sartorius. Qundriceps. Rectus femoris. Vastus extern. Vastus inter Pia. 25. — Motor points on the front of the thigh (Erb), standing on the other foot the pelvis is inclined on the affected side, and hence, in walking, there is an oscillation of the trunk, which becomes very con- siderable if the muscles of both sides are affected. Moreover the unopposed tone of the outward rotators produces a permanent rotation of the leg, so that the toes are directed outwards, and, from the altered position of the foot, the propulsion of the body in walking is deficient. The Pyriformis, Gemelli, Obturator internus, and Quadratus femoris (special nerves from the sacral plexus, but from L. 5) all rotate the thigh out- wards, and the first-named muscle, in addition, carries the thigh obliquely backwards and outwards, in the same way as the posterior fibres of the gluteus medius. In paralysis of these muscles external rotation is impossible, and the unopposed tone of the internal rotators (anterior fibres of the gluteus medius and minimus) causes the leg and foot to be habitually turned inwards. The Psoas (special lumbar nerve, L. 2 and 3) and Iliacus (anterior crural nerve L. 2 and 3) flex the hip-joint, and, in doing so, cause also a slight rotation outwai'ds. In paralysis, flexion is lost, and the use of the leg in walking becomes impossible. The Tensor vagina femoris has a slight power of flexing the hip, and at the same time rotates the thigh in. It normally counteracts the tendency of the MUSCLES OF LOWEE LIMB. 47 ilio-psoas to rotate outwards. If it is paralysed, there is a tendency for the foot to turn out when it is being brought forward in the act of walking. Adductors of the Thigh (all are innervated from the same roots, L. 2 and 3). —The Pectineus (obturator nerve) causes an oblique movement forwards and inwards, i. e. a combined flexion and adduction, as in crossing the legs. It also rotates outwards. The Adductor longus, and probably the Adductor brevis (obturator nerve), have the same action, but the flexion is less than by the pectineus. The Adductor magnus (obturator and great sciatic) causes a similar adduction, but while its upper fibres rotate outwards its lower fibres rotate in, and are employed in keeping the foot straight during adduction in riding. This is very difficult if these fibres are paralysed. The foot then turns out when the hip is flexed, either in the recumbent posture or in walking, from the preponderance of rotation out by the other adductors. When all the adductors are paralysed, not only is adduction lost, but in flexion of the hip the foot is moved forwards and outwards, instead of directly forwards, showing that there is normally a synergic action of the abductors and adductors with the flexors in this movement. Muscles moving the Knee. — Extensors : Rectus, Vasti, and Crureus, together called the E. quadriceps (ant. crural nerve, L. 3 and 4). — The vasti act solely on the knee-joint; the rectus also aids in flexing the hip, but chiefly when the knee is bent. In consequence of its passage over the hip-joint, moi'e- over, the force with which it extends the knee is increased by the simultaneous extension of the hip. This efHect is useful in the propulsion forwards of the body in walking. The crureus is unimportant. In paralysis of the extensors of the knee, standing is still possible if the knee is extended, since the arrangement of the articulation renders a contraction of the extensors unnecessary. But secondary shortening of the flexors is apt to occur, and then standing becomes impossible because the knee cannot be perfectly extended. In the same way, walking is possible if the leg is not moved forward beyond the vertical position ; if it is, the knee becomes flexed by the weight of the leg and foot, and the patient falls when he attempts to rest upon it. Rising from the kneeling posture in the ordinary way is impossible. In partial paralysis of the muscles, as in pseudo-hypertrophic paralysis (q. v.), the exten- sion of the knee, in rising, is facilitated by placing the hand upon it, and so bringing the centre of gravity of the body near the fulcrum of the lever formed by the femur. If the vastus internus and rectus are paralysed, the vastus externus may dislocate the patella by the obliquity of its traction. The vastus intei'nus never does so in the opposite condition, because its action is less oblique. Flexors of the Knee. — These are all supplied from the same spinal roots, although through various nerves — L. 4 and 5, S. 1. — The Sartorius (ant. crural nerve) flexes the hip- and knee-joints, and has a feeble power of rotating the thigh outwards and the knee inwards. It is a muscle of small importance. The Gracilis (obturator nerve) adducts the thigh more powerfully than it flexes the knee. It rotates the leg inwards. The Semitendinosus, Biceps, and Semimerribranosus (great sciatic nerve) are not only flexors of the knee but extensors of the hip-joint, and are the muscles that extend the hip during ordinary walking, the gluteus maximus (q. V.) being called into action only during special efforts. The leg is rotated inwards liv the semitendinosus, outwards by the biceps. In paralysis of the flexors the resulting loss of the power ■)£ flexion interferes 48 ACTION AND PARALYSIS OF MUSCLES. with walking, since the knee-joint cannot be bent, in the forward movement of the leg, until the thigh is flexed sufficiently to permit the weight of the foot to flex the knee. To prevent the toes striking the ground the foot is unduly flexed on the leg. The loss of the support that the flexor tendons give to the knee- joint leads to an undue strain on the ligaments, which become stretched, and slight retroflexion of the joint may occur. In paralysis of the muscles that extend the hip, there is a tendency to fall forwards in walking. To counteract this the trunk is carried backwards, and a fatiguing strain on the flexors of the hip results. In paralysis of the biceps, the leg, during flexion, is rotated inwai'ds ; when the biceps remains and the other muscles are paralysed, there is an undue rota- tion outwai'ds. The effect of these abnormal movements on the ligaments of Tibialis anticus, Extensor digit Peroneus brevi Extensor long, po': Dorsal interosse Ext. poplit. n. Gastrocnem. (outer head). Peroneus longus. Soleus. Flexor long. poUicis. Extensor brev. digit. Abductor minim, digit. Pia. 26. — Motor points of leg, outer side (Erb). the joint is such that, after a time, the amount of rotation becomes greater than is possible in health. The Popliteus (internal popliteal nerve) has but a feeble power of flexing the knee. Its chief action is to rotate the leg inwards when the knee-joint has been flexed. Muscles movhto the Foot. — Extensors of Foot on Leg* — The Gastro- cnemius and Soleus (internal popliteal branch of the sciatic — L. 5 and S. 1) • These muscles are sometimes termed " plantar flexors,** because they are homo* logons with the flexors of the wrist. The term is a bad one, since it involves a nse MUSCLES OP LOWER LIMB. 49 have the same action. They extend the hinder part of the foot and draw down the outer side of the forepart of the foot, but very little the inner side. Hence the foot is rotated, so that the dorsum looks outwards, while the whole foot is Sciatic n. ^i Biceps (loug head) Biceps (short head) Sxt. poplit. n. Gastrocnem. (ext. head) Soleus Flexor long. poll. Gluteus maximus. * Adductor magnus. Seniiteiidinosus. Seiidmembranosus, Int. poplii. n. Gastrocnem. (int. head). Soleus. Flexor digit, comm. Tibial n. Fig-. 27. — Motor points, back of thigh and leg (Erb). turned inwards on the axis of the leg. The peculiar inversion and adduction that thus accompanies extension is due to the form of the articular surfaces. The gastrocnemius has very little power of flexing the knee, but the extension of the word •' flexor " in absolute contradiction to its proper signification. We ought not to frame a descriptive term such as this on an analogy which involves a contradiction to the description. Flexion is bending, a movement from a straight line; and extension is less bending, a movement towards a straight (stretched, extended) line. To call a movement townrd a straight line " flexion," because in the arm the similar movement produces this effect, is a process that is not description, but the statement of an analogy — the worst possible kind of nomenclature. Names should be descriptive or they should be arbitrary. Neither theory, nor analogy, nor homology should have any part in them. What we call homology is merely a species of analogy; it rests on inference and reasoning, not on simple absolute aspect. Nothing that rests on reasoning is inherently stable and free from change. VOL. I. 4 50 ACTION AND PARALYSIS OF MUSCLES. of the knee increases the effect of the muscle on the ankle-joint, especially in walking, just as we have seen that the extension of the hip augments the force with which the contracting rectus extends the knee. For direct extension of the ankle, the peroneus concurs and opposes the inversion. The only diffei'ence between the gastrocnemius and soleus is that the latter, having no attachment to the femur, can extend the ankle when the knee is flexed as well as when it is extended. In paralysis of these muscles, extension of the ankle (by the peroneus longus and flexor longus digitorum) is extremely feeble, and the foot can scarcely be carried beyond a right angle. Walking is greatly interfered with ; standing on tiptoe is impossible. The unopposed peroneus longus causes eversion of the foot, lowers the head of the first metatarsal bone, and deepens the plantar ai'ch. In time the ankle-joint becomes over-flexed, the heel considerably lowered, and the plantar muscles and fascia become shortened. The resulting deformity is termed talipes calcaneus (Fig. 28). 'A Fia. 28. — Talipes calcaneus from atrophic paralysis of the calf muscles, with flexion of tlie middle and distal phalanges of the toes, from paralysis of the interossei. The 'p&roneus longus (musculo-cutaneous nerve, from external popliteal of sciatic — S. 1 and 2) everts the foot, lowering the inner border, narrowing the foot, and increasing the plantar arch. It also turns the whole foot out on the axis of the leg. It has a very feeble power of extending the ankle. It keeps down the inner part of the foot during extension by the calf muscles, as in walking. In paralysis of this muscle the inner part of the front foot is not supported during extension, and yields to slight force. The foot becomes adducted and rotated, so that the sole is directed inwards, in consequence of the unopposed action of the sural muscles. The inability to press the inner part of the ball of the foot firmly against the ground leads to over-action of the flexors of the great toe. The plantar arch is lessened ; there is " flat-foot." Flexors of the Foot. — (Both are supplied by the anterior tibial bi'anch of the external popliteal nerve — L. 5 and S. 1.) The Tibialis anticus produces simul- taneously three movements : it elevates the inner part of the front foot (oppos- ing the peroneus longus) ; it flexes the ankle-joint, and addncts the foot. The Extensor longus digitorum, besides extending the toes, flexes and abducts the foot. The abduction is in consequence of the outward position of its tendons beneath the annular ligament. These two muscles together produce direct flexion of the foot, or flexion witli adduction or abduction, as the force of one or the other preponderates. Paralysis of either weakens flexion, and the corre- sponding lateral movement is lost, flexion being accompanied by the deviation effected by the muscle that remains. The defect in flexion is greatest in para- lysis of the tibialis, and the loss of the instinctive flexion, when the leg MUSCLES OP LOWES LIMB. 51 ii brought forward in walking, canses the foot to catch against the gronnd. Paralysis of the flexors is followed by seoondaiy contraotuie of the extensors, FlO. 29. — ^Talipes equinns, dae to atrophy of the tibialis anticus and secondary contracture of the calf muscles. In A the foot is shown at rest ; there is slight equino-varus. In b it is shown during flexion, and the vams is changed to valgus by the action of the peronens longus. Note the increased extension of the toes in B from the com> pensatory over-action of the long extensors of the toes. (After Duchenne.) •nd talipes equinus results (Fig. 29), which is the greater the longer the palsy has lasted (Fig. 30). Its occurrence is facilitated, in many cases of palsy. Fio. SO. Fia. 81. Fio. 30. — Extreme talipes eqainns from old-standing palsy of the tibialis anticus (infantile paralysis) and extreme contraction of the calf muscles. No flexor movement was possible. Fig. 31. — Paralysis of the interossei and the adductor and short flexor of the great toe. The first phalanges are over-extended and the second are flexed, while the hollow of the sole is increased. (After Duchenne.) by lessened growth of the bones of the leg, so that the ball of the foot only touches the ground when the foot is extended. There is usually slight rotation inwards of the foot at rest, even when the tibialis is paralysed (see Fig. 29, a), because such rotation is produced by the sural extensors (p. 42) ; but in this case the slight valgus at rest is changed to varus on an attempt to flex the ankle (Fig. 29, B). 52 ACTION AND PARALYSIS OP MUSCLES. The Peroneus brevis (musculocutaneous [peroneal] branch of ext. popliteaJ nerve — S. 1 and 2) abducts the foot and rotates it, raising the outer edge. The Tibialis posticus (posterior tibial nerve from int. pop. — L. 5 and S. 1) adducts the foot and curves it, rendering the outer border and instep more convex, Its power of adduction is greater than that of the tibialis anticus, and it does not rotate the foot in the same manner. These two muscles alone have the power of adducting and abducting without flexing or extending ; and in their paralysis these simple movements are lost. If one only is paralysed, a deformity develops corresponding to the action of the other muscle, — talipes valgus in paralysis of the tibialis posticus ; t. varus in that of the peroneus brevis. The muscles moving the toes present, in their mode of action, a close corre- spondence to those of the fingers. The Extensor longus digitorum and the Extensor longus pollicis (anterior tibial nerve— L. 5 and S. 1) extend chiefly the first phalanges, while the Flexor longus digitorum and Flexor brevis (postei-ior tibial nerve — S. 1 and 2) flex the last two phalanges. The Lumbricales and the Interossei (post, tibial nerve by ext. and int. plantar — S. 1 and 2), together with the Abductor and Flexor brevis m,inimi digiti, oppose both the other extensor and flexor muscles, flexing the first phalanx and extending the others. This action is of great importance in walking, since they give the last propulsion to the body as the ball of the foot leaves the ground. The Abductor, Adductor, &vi^ Flexor hrevis jpollicis (plantar nerves fi-om post, tibial — S. 1 and 2j have a similar action on the great toe, but with adduction or abduction respectively. The interossei also produce a lateral movement of the toes, but this action is of little practical importance. In paralysis of the common extensor of the toes, and of the proper extensor of the great toe, the tonic force of the interossei and analogous muscles produces persistent flexion of the first phalanges and extension of the others. If the conditions are reversed, and the latter muscles are paralysed, the first phalanges are over-extended, sometimes even subluxated, and the two other joints are flexed, so that a claw-like form of foot is the result (Figs. 31 and 28). The final propulsion in walking, above described, is much interfered with, and the attempt is painful because the ends of the toes are turned towai'ds the ground. Other examples of the effects of paralysis of the muscles of the arm and leg are given in the illustrations to the chapter on Infantile Paralysis (Acute Polio-mjelitis^. 53 THE GENEEAL CONSTITUTION OF THE NEEVOUS SYSTEM* Our conceptions of the elementary arrangement of the nen oua system have been changed during the last nine years by important histological discoveries, which clear many obscurities, give new signi- ficance to facts before imperfectly perceived, and involve new patho- logical conceptions, general and special. Although new difficulties have arisen, as they must do at each step forward, numerous facts, which before were mysterious, become intelligible, and their elucidation con- stitutes confirmation of the truth of the discoveries. The evidence has been received as adequate by aU physiologists. Pathologists must therefore accept them, and reconstruct their conceptions. It is accordingly necessary to give an outline of the constitution of the cerebro-spinal nervous system as at present discerned, even of that which is not of direct present application to pathology, but which may become so and is essential for the perception of the whole. The facts have been found also to be true of the sympathetic system.f These discoveries are the result of a method of metallic staining, first devised in detail by G-olgi of Pavia, in which silver is reduced in the structures that have been impregnated with chromiimi during hardening, and usually also acted on by osmic acid. It displays the minute structure of the grey matter with a distinctness and in a manner that reveal facts before altogether unseen. Almost the first definite steps were the results obtained in the Inver- tebrata by Nansen, before he turned his face from polar cells to Polar seas. But the first important disclosures, which involved the radical <5hange in conception, were due to Ramon y Cajal of Barcelona J and to the veteran v. K6lliker,§ supplemented and diffused by Waldeyer.|| Since 1890 there has been incessant work at the subject, and y Cajal has presented to us the chief facts that had then been ascertained, in the Croonian Lecture to the Eoyal Society in 1895. All nerve-fibres are prolonged processes of nerve-cells. They consist of an axis, with a " medullary sheath " around it when the course is long, either within or outside the central organs. Most cells have but • The interpolation of this account of the recent revolution in fundamental elements of our knowledge, although not quite consistent with tlie plan of the book, «eeras the most convenient way of presenting the facts to the reader. They pass below, and rise above, the range of practical knowledge which can he used in common work, and yet are changing our physiological and pathological conceptions in a manner *nd degree which must be adequately recognised, although much of their effect is ttill uncertain. t V. Kolliker, " Histol. Mittheil.," • Wurzburg, Sitznngsb.,' Nov. 23rd, 1889. X Previously, • Internat. Monatschr. f. Anat.,' 1890, Bd. vii. § Loc. cit. II ♦ Berlin, med. Wochenschr.,' 1891, No. 28. 54 ACTION AND PAEALTSIS OP MUSCLES, one such medullated process, larger tlian tlie otliers ; some hare two. The other processes are short ; thej soon divide and branch withio the grey substance : the long medullated processes also at last end by dividing and ramifying. The conception formerly held may be thus stated. Of the ultimate divisions of the short, quickly -branching processes in the grey matter, some had been thought to join the terminations of similar processes from other cells, either neighbouring cells in the grey matter, or the terminal branches of medullated nerve-fibres, processes of cells far away. Thus, of the motor cells of the spinal cord, some of the processes, passing backwards, were believed to join those of sensory cells in the posterior cornua, of which the medullated process was a fibre of the posterior root. The constituent elements of the nervous system thus formed, by branch union, one continuous complex net- work, with paths for the nerve-impulses, due to union and continuity of the cell-processes. The paths in actual use were determined not only by such union, but also by differences in " resistance " among those which continuity provided. The " resistance," which thus per- mitted an energetic impulse to spread more widely than a slighter one, was varied in degree by fxmctional activity ; it was diminished by the repetition of the same activity, and it was also varied myste- riously by other nerve-impulses from various sources It might thus be increased so as to "inhibit" action. In so far as any attempt was made to conceive its seat, it was thought of as in the cells, or in the feltwork of uniting processes in the grey substance, called " spongy,** from its blending trabeculse. Much of this conception is retained. But the more the methods of examination were improved actual luiion of the branches of cell-processes became less perceptible under the microscope. The development of the use of staiaing agents, especially metallic, has increased the power of discrimination. Yariety of aspect can be thus produced in structural elements that before were indistinguishable. By the use of such methods, and especially that of Golgi, the branches of the processes and fibres have been clearly traced, and they have been found not to unite. They are distinctly seen to end in the structural material ia which the nerve-cells lie, sometimes by an enlarged knob-like extremity, sometimes by a poiat. Often the branches cross and even interlace, with the semblance of union, but close observation shows that it is a semblance only. Discontinuity is found to be the general rule. Whether invariable or not is still undecided; it is most difficult to exclude union in the dense felt of fibrils which the branching processes form in some parts, the " neuro-pUema " of His, and, moreover, the general rule of free endings is compatible with occasional actual union.* From this it follows that the " nervous system *' consists of discon* • Cf. Masius, 'Arch, de BioU' 1892; Fritsch, • Brit. Assoc. Report,' 1892. GENERAL CONSTITUTION OP THE NERVOUS SYSTEM. 55 tinuous elements, each a cell-body with its processes, long and short. For these elements the name "neuron," proposed by Waldeyer,* has been all but universally adopted ; for distinctiveness, its plural is formed according to the living language, and not the classical form — in English it is " neurons," in German, " neuronen," in French, *' neurones." The chief process, the medullated, or axis-cylinder process, is called the " axon," or " axis-process." f The branching processes in the gi*ey matter are termed the " dendrons," the branches of these " dendrites." t From the axons there often spring fine fibres, which pass off at right angles, termed " collaterals " by Ramon y Gajal, "the relations of which are imperfectly known. They have been seen to end by a T-like division and ultimate branching. The definite and extended discernment of another fact deepens the importance and application of that just described. Thirty years ago § Max Schultze discovered and depicted the fact that the axis-cylinder is compound and not simple, that it consists of a large number of fibrils, — " primitive fibrils," he termed them. He pointed out that they could be traced throughout the fibre, separated by a finely granular substance. They could be well seen where the axis-cylinder widens in joining the nerve-cell, that is, where the cell narrows into its chief process. Others could not see the significant striation, among them Eanvier, whose work domi- nated science throughout the next fifteen years, || and the fact was practically ignored. The axis-cylinder was regarded as simple and integral, \mtil recent methods have enabled the clear establishment of the correctness of Max Schultze's observations. The niimber of fibrils that constitute an axis-cylinder is considerable. Obersteiner has found that there are about fifty in an axis-cylinder of the sciatic nerve of the frog. If * Loc. cit. t Because the " axon " is the separate *' nerve," wlien one exists, an attempt has been made to make current the nse of " neuron " for this alone. But etymo- logical consistency has little influence on the vitality of names. The use of "neuron "for the whole element has become so general th;it lesistHnce to it is futile. Moreover, the conception attached to it in use is already definitely detached from its etymology. Lastly, although the cell-body and its processes are one, to have only the word " cell " for the whole element, a word that will still, inevitably, be applied to the cell-body, leaves the latter without nominal distinction from the other two pans of the element — the neuron and the dendrons. Hence the word " neuron " is here used in the established senses. X "Dendrite" has also been used as equivalent to "dendron," and still is; but the need for distinguishing the twi^rs from the process itself makes it highly probable that this convenient separation of the words will become universal. § In 1868 ; see Strieker's * Histology ' (New Syd. Soc. trans.). The obtervationa were confirmed by Babuchin in 1868 and 1869. II See further on Structure of the Nerves, p. 62. •JT Personal communication. 56 ACTION AND PARALYSIS OF MUSCLES. These fibrils consist of a conducting substance, tbe " hyaloplasm " of Leydig and Nansen (so termed from its greater translucency in hardened tissue). This is isolated by a slightly granular material, distinguishable chiefly by its difference of aspect and staining after the changes produced by hardening agents. It has been termed the " spongioplasm " — " plasm " because it also has a soft consistence, " spongio " because it is said to form trabeculae, which constitute the chief element in the groimd substance, or matrix, of the " spongy " grey substance* in which the cells lie and their processes branch. From this compound constitution of the axis, we must infer that its terminal division, into branches is merely the separation of these fibrils, first into groups, and at last into single fibrils — " primitive fibrils." It is so at the periphery and in the grey matter. The final twigs may be termed " axites," if a special designation seems needed.f The short branching processes have been found to consist of similar fibrils, and this is true also of those supposed to be extensions of the substance of the cell, and therefore called " protoplasmic processes." This name should be given up with the conception attached to it. The opinion that their function is to convey nutritive material to the cell-body was, indeed, never more than an hypothesis, resting on no real foundation. J With the recognition of the fibrillary constitution of the axon and dendrons, has been associated an equally important recognition of the fact (most clearly depicted by Max Schultze §) that their fibrils pass through the body of the nerve-cell without interruption. Those of the axon diverge to pass to the several dendrons, but those of the latter do not pass all to the axon. Some pass directly to other dendrons, so that, in such, there must be conduction from the cell as well as towards it.|| Moreover, both y Cajal and Kolliker have observed, in certain cells of the cerebellum, all the fibrils of an axis-cylinder pass directly to a dendron, scarcely entering the body of the cell. Twigs from such processes of small cells, especially in the Inver- tebrata, have been said to join the elements of the neuroglia.^ The • Apathy, 'Biol. Ceutialbl.,' 1889. The term "spongy grey substance" was before in use on account of the sponge-like interlacement of the cell-processeB. The conception attached to it has thus become somewhat confused. t Especially since one writer has termed them neurites, which would be confusing unless the axis-proceps were termed the " neuron," as it certainly will not be. The only projier use of this word (neurites or neuronites) would be for the terminal twig.s in general. J That these dividing branches, long, and not obviously permeable, should be the channels by which the cell receives that which could pass directly through its walls, was simply a positive inference from the negative fact that no other function was obvious. That we must cease to consider these processes " protoplasmic** and nutritional was insisted on in 1890 by Rabl Ruckhardt (' Neurolog. Centralb.'). § Loc. cit. (I V. KoUiker, ' Wuitzburg. Sitzungsb.,' Nov. 23rd, 1889. ^ Among others by Ladowsky, ' Verhandl. Med. Congress,' Berlin, 1890, ii, 92. GENERAL CONSTITUTION OF THE NERVOUS SYSTEM. 67 fact is in harmony with the origin of both from the same embryonal tissue. The differentiation of the nerve-elements from this, may leave some blending of structure. It must be remembered that there is much uncertainty regarding the natiire of many of the smaller cells, and it is conceivable that some are nervous and some neuroglial, and that there may not be always actual separation of their connections. An essential difference between the axon and the dendrons cannot as yet be established. Branching does not differentiate them, for the axon also branches after a longer course. Nor does either multiplicity or length. The cells of the posterior ganglia of the cord have but one axon and one dendron, united for a short distance as the single process of the " unipolar " cell. These two processes are of nearly equal length in the case of those cells that give rise to the fibres of the posterior median column ; these, reaching the cord by the posterior roots, ascend to the level of the medulla, while the other division of this cell-process probably comes from a muscle as far away. We see also, La this instance, the absence of any real distinction from the direction of con- duction. Although the axons of the motor cells conduct from these, so also must some of those dendrons to which fibrils pass from others. Moreover, in the case of the posterior root-fibres which go to the local grey matter, the long fibre from the periphery conducts towards the cell ; the shorter fibre, which soon branches in grey substance, con- ducts from it. Opinions may differ as to which should be regarded as axon and which as dendron, but analogy suggests that the latter should be that which soon ends in the grey substance. But it is difficult to avoid regarding each fibre of the cells related to the posterior median column as an axon. There is no reason for regarding either a dendron or an axon as an essential element of a cell. Yet the distinction is necessary, and the general application of the names is justified by the common difference between the one medullated process, which passes out of the grey matter, and the other numerous processes, which are not medvdlated, and soon divide within the grey substance. The extent to which the physiology of the nervous system is inferred from its minute anatomy, is illustrated by the revolution in our con- ceptions produced by the discovery of the discontinuity of its elements, the fibrillary constitution of the conducting structures, and the course of the fibrils. These, passing through the nerve-cells, without inter- ruption, can merely conduct through the cell-body as they do elsewhere in their coui'se. With this fact disappears the old idea, so simple, apparently so adequate and reasonable from its superficial analogies — the idea that the nerve-cells are the seat of the production of nerve-impulses, that in them " nerve force " is generated from the latent energy stored in the nutritional compounds which have entered into their constitution. But we cannot have such generation where the fibrils are continuous. For it, we must look to their extremities, formerly supposed to be in the cell-body, now perceived to be in the 58 ACTION AND PARALYSIS OP MUSCLES. " spongy grey substance." TKe process must be wliere the continuous fibrils begin in the centre, as it is in the skin and other parts of the periphery, in the case of fibrils that conduct thence. As all the nerve- impulses that reach the centres, through which external influences act, and the environment is perceived, originate in the minutely separate nerve material at the extremity of the afferent fibrils, so all the out- going impulses, and those which pass from one part of the centres to another, originate in their special form at the analogous extremities of the fibrils in the grey substance. We must conceive these impidses arising in the extremities of the " cellulipetal " dendrites (to use the somewhat cumbersome term of v. KoUiker), being excited in some way by the stimulus of the impulses which reach the contiguous extremities of other " cellulifugal " fibrils, dendrites or branches of the axon of a distant cell. The incoming impulses may excite those that go out, as impulses are excited at the periphery by other forms of energy ; or there may be a process of conduction, through the intervening ground-substance, — the matrix in which the cells lie and the dendrites end. For the increase in the amount of nerve- energy which often takes place, there must be more than conduction, its production must be " excited " by that which is conducted. We can conceive such excitation without continuity, especially when we con- sider that the stimulation of muscular protoplasm is by the impulses in nerves which terminate on the fibres, and not in continuity with the contractile substance — indeed, separated from it by a structure apparently quite different in its simpler nature. If this conception of the origin of the impulses in the terminations of the fibrils seems less easy than their origin in the more massive nerve-cells, we must remember how multiphcity neutralises minuteness. Indeed, the minuteness of the conducting fibrils almost involves a multiplicity of minute sources of nerve-impulses, — ^which must, more- over, be far from minute in comparison with the molecules, from the latent energy of which the impulses proceed. All modem discoveries prepare us for finding every mass to be an aggregation, and each perceptible quantity of energy to be made up of minute constituents, every one of which is definite, both in its separate character and in its contribution to the effect of the whole. The finely divided nerve- substance will constitute a total source of energy, as adequate in extent as a nerve- cell, with a more obvious facihty for the renewal of the molecules lost in functional action, and far greater opportunity for varying relation to the structures from which the impulses are received. What, then, is the function of the nerve-cell ? The one certain fact, established by evidence that is secure, is that on it depends the life of the nerve-fibres — the vitality of all the processes, equally that of the dendrons and of the axon. The evidence of this, the immediate degene- ration of any separated part, is well known. It is less conspicuous in the case of the dendrons, but sufficiently certain. How the influence GKJMEliAL CONSTITUTION OF TH K NKRVOUS SYSTEM. 59 is exerted we can only snrmise. The nucleus of every cell is its life centre, and in some way the nutrition of the protoplasm is determined by it. The cell-body has a complex structure, dimly perceptible by the help of reagents, at present beyond our practical comprehension. One distinct fact, however, is that the protoplasm of the cell, extend- ing into the narrowing axon, thins away between the outer sheath and the white substance, becoming unrecognisable until one of the many nuclei is reached. Each of these is surrounded by like protoplasm, also thinning of£ along the fibre until invisible. It is certain also that if the cell-body and nucleus are destroyed, or the fibre separated, the pro- cess of degeneration begins by changes in these nuclei. They seem to be concerned in carrying on the influence of the distant cell, and it is not easy to conceive any other path for this influence than a thin layer of protoplasm, within the sheath, continuous from nucleus to nucleus, vitally influenced by these, and conveying, by its own nutri- tional state, that of the cell. A space, in this position, is rendered visible by reagents which make the contents of the sheath shrink. Indeed, coagulated material, in small quantity, can be seen within it.* This has been regarded as evidence of the presence during life of such a space as is here assumed to contain connecting proto- plasm. Many facts, previously obscure, become more intelligible in the light of the new discoveries. The knowledge that the cell governs the nutrition of the fibi-e, and the belief that from it proceeded the nerve- impulses, involved a correspondence in the direction of nutritional in- fluence and of conduction, and it was found, in fact, that conduction and degeneration were in the same direction as a rule — but only " as a rule." It was untrue of the sensory nerves. These, coming from the cells of the ganglia on the posterior spinal roots, degenerate downwards, but they conduct upwards — an anomaly which had to be simply ignored. The fact is now seen to be in harmony with others. The arrest of secondary degeneration in the grey matter, the fact that the degeneration of the fibre which enters the grey matter never passes on to the next nerve-cell, through which conducted impulses must pass, was mysterious when they were believed to be in continuity. The discontinuity explains it at once. The degeneration is limited to the single neuron. The division of the axis-cylinder at its terminal ramification, whether that of the sensory nerve in the skin or of the motor nerve in the muscle, was scarcely intelligible when the axis-cylinder was regarded as a single conducting path ; it is so when we perceive that the apparent division is simply the separation of its constituent fibrils, each a dis- tinct conducting path. This fact is, moreover, especially important in relation to the minute localisation of the various forms of sensation in * ScbiefEeidecker, * Arch, f . mik. Anat,,' xxx, 1887. 60 ACTION AND PARALYSIS OP MUSCLES. the skin. The sensory nerve-fibres themselves are not numerous enough to subserve this localisation, which could not result from the division of an axis-cylinder that conducted as a whole. The fact that the special form of energy termed a " nerve-impulse ** may arise in a fibre in its course under the action of a stimulus, that the capacity of the fibres is not limited to " conduction," is less surprising if we conceive all such impulses as produced at their extremities. While old difficulties thus disappear, and many facts become more readily intelligible, so great a change of our conceptions involves new difficTolties. Not onJy are the structures concerned most minute, but their discernment depends on the use of reagents which reveal them by developing differences in aspect due to chemical changes; new physical characters have been produced by other agents of the same nature. There seems but little original difference in consist- ence between the material that constitutes the conducting axis of the " primitive fibrils," and that of the separating substance. Both are apparently almost diffluent during life, and are indistinguishable physically until their difference in constitution is revealed by the action on them, first of the chemical agents that harden, and then of those that stain.* Both processes involve molecular chemical changes, which multiply initial differences, and leave the actual amount of these more obsciire than we are apt to think. The conducting element of the fibrils, the " hyaloplasm," or " kine- toplasm," is said to be more diffluent than the separating " spongio- plasm," but the difference may be chiefly due to the hardening agents used. Continuous within the tubules, and through the cell-body into the dendrons, it has been said that beyond these it is also continuous with similar material in the matrix of the spongy substance. Into this also the spongioplasm is said to pass and form a trabecular structure. The fact that the fibrils, as stained by Golgi's method, apparently end, must indicate that these elements, if continuous with those of the matrix, are different in nature in some degree. The difference may be much exaggerated by reagents, and yet sufficient to constitute the functional discontinuity which is generally assumed to be as stmctur- ally absolute as it appears in the sections. Until we know what the structure of the matrix is, we can scarcely conjecture the nature of the process that occurs in it between the dendrites. " Conduction " may have been too readily regarded as * la connection with the fact that molecular differences between substances apparently the same, even when examined with the utmost minuteness, may be revealed by staining, the facts of the colour photography of Cassagne may be noted. The waves of light which differ only in rapidity and length, but by this excite different elements of the retina, reduce a special silver snlt in the gelatine film in different degree. Extremely slight as must be the resulting difference in the molecules which is produced, it apparently suflSces, augmented by some additional chemical process, to make each of them retain some stains and not others. GENERAL CONSTITUTION OF THE NERVOUS SYSTEM. 61 impossible, and it is not clear tliat actual conduction of nerve- impulses is incompatible with the augmentation we include under the term "excitation." An increase must occur when, for instance, in many reflex actions the afferent impulse that reaches the spinal cord is minute in proportion to that which leaves the centre. We seem thus to have a process of stimulation comparable to that in the cutaneous nerves (themselves apparently analogous to dendrites), under the influence of some other form of energy from the outside. In this connection it is especially noteworthy that many dendrites terminate in knob-like enlargements, suggesting receptive functions. "We do not know the nature of a "nerve-impulse." We must, however, assume that it is energy in some form of motion, released from that previously latent in the nerve- substance, apparently the •' kinetoplasm " or " hyaloplasm." Chemical change occurs by which simple compounds are formed, as in aU similar processes, and the simplest conception is that the process is like that in a train of explosive material, modified, restricted, but perhaps accelerated by the influence of life.* The motion of a touch, which acts upon the nerve-endings in the skin, reaches them by passing through the skin as the simplest form of motion ; so also pass the special forms of wave motion that con- stitute electricity and heat. A differentiation of the nerve-tissue in the ending seems to enable their molecules to receive one special form of motion most readily. Hence our " special senses." The manner in which the equilibrium of the nerve- substance is disturbed in each doubtless differs much, but it is instructive to note in connection with the theory of the nerve-impulse just suggested, that the wave-motion of light seems first to induce recognisable chemical changes in material of unknown nature. • This view has been developed at length in the writer's ' Dynamics of Life,' London, Churchill, 1894, but was clearly stated by Herbert Spencer, 'Elem, Biology,' vol. i, 1864. e2 DISEASES OF THE NERVES. GENERAL PATHOLOGY. Steitctttei!. — Each individual fibre consists of a central core, or "axis-cylinder," surrounded by the "medullary sheath," or "whibe substance of Schwann," and a delicate membranous sheath enclosing it. The axis-cylinder is the func- tional element, that which conducts the nerve im- pulses. It was long thought to be homogeneous, conducting as a whole, like an insulated wire, but it is now recognised to be a compound structure, in consequence of the recent researches of which an account has j ust been given. The separate " primitive fibrils " of which it consists are sufficiently numerous to be of great physiological importance, an axon according to its size, containing apparently from thirty to fifty (see p. 55). They were, as has been stated, described thirty years ago by Max Schultze ; but, although his observations were not luiconfimied, those investigators whose work had most influence, notably Eanvier, failed to recognise them. The axon has been practically regarded as simple until the last few years. Indeed, the methods of histological inves- of the structure tigation by which its fibrillary structure can be of nerve-fibres. I recognised are stiU outside the range of ordinary later! Ill non- iiiicroscopical pathology. For this, that which was mednllated fibre; before discerned retains its importance, because it S, sheath ; M, -g g^^jj all that can be applied to morbid changes, invehn, or white -"^^ ° The "medullary sheath " (M, Fig. 32) consists of myelin, a liquid fatty material, supported by a fine network of homy substance, "neurokeratin." This IS, incision of sheath is absent ia the " non-meduUated " fibres of Schmidt. (From ^]jq sympathetic. A delicate membrane surrounds a preparation of ,, , ., , , ,, • •,. -, .■, ,, the nerve-fibre of "the white sabstance, the " primitive sheath, or afrog,«tainedwith " neurilemma," or " sheath of Schwann " (S). Nuclei osmic aci .; ^^^ y[q at intervals within the sheath, between it and the myelin. The white substance is interrupted at regular distances by what are termed " nodes," — sometimes, from their discoverer, "nodes of Tlanvier " (N). The end of each portion, or "inter- node," is enclosed by the sheath, through which the axis-cylinder passes. Between the incurved extremities of the sheath is a little Fig. 32. — Diagram Bubstaace of Schwann; Ac.axis- cyliiider; n, nn- clens ; N, node ; incision PHYSIOLOGY OF NEEVES. ^'S dear cementing substance, shown by tbe fine dotting in tbe figure. Tbere is one nucleus (n) to each internode, about its middle ; hence they are sometimes called "internodal nuclei." Around the nucleus is a little protoplasm, and it is probable that a very thin layer of protoplasm everywhere lies between the sheath and the myelin connecting that of the adjacent nuclei, and these with the protoplasm of the nerve-cells (see p. 59). The internodes are shorter towards the termination of a nerve. It is important not to confound these divisions with other imperfect indentations (IS, Fig. 32, I), often called the. "incisions of Schmidt," or "indentations of Lautermann." * These are oblique, incomplete divisions of the white substance. Many exist in each node. They are believed by some histologists to be of artificial origin, but their uniformity is in favour of their dependence on some structural feature. The myelin, Ranvier suggests, must protect the axis-cylinder, since its almost hquid consistence will diffuse pressure on the nerve. Other possible uses it subserves may be suggested, but we have no proof of them. The nodal segmentation evidently permits nutrient material to reach the axis-cylinder. The "grey fibres," or " non-medullated fibres," consist of an axis- cylinder, sheath, and nuclei (Fig. 32, III), but contain no myelin. They constitute the sympathetic nerves, but some (also probably sympa- thetic fibres) are found in all the spinal nerves. They are absent from the nerves of special sense except the olfactory, which contains no other fibres. The nerve- fibres are tmited into " fasciculi " by delicate nucleated connective tissue, and these fasciculi are similarly connected into larger bundles, while the whole nerve is surrounded by a dense connective- tissue sheath or " perineurium." Under this sheath, and extending between its lamellae and amongst the individual nerve-fibres, there is a lymph-space lined by flattened endothelial cells, which probably plays an important part in the propagation of inflammation. From the perineurium a very delicate "sheath of Henle" extends on to the ultimate divisions of the nerve. AU these tracts of connective tissue and spaces are continuous, and they convey the blood-vessels. They also contain nerve-fibres, " nervi nervorum," which are derived from the nerve itself.f The sheath and connective tissue of each nerve are thus part of the area of distribution of its own fibres. PHYSiOLoaT OF Neeves. — The first great fact to be kept in view is that the axis of each nerve-fibre is the prolonged process of a nerve-ceU, the wall of the cell and process being continued as the sheath of the nerve-fibre, the protoplasm of the cell becoming less and less as the process narrows, and the white substance, the medullary sheath, making * They were first described by Schmidt of New Orleans, and afterwards by Lautei'innnn. t Hoisley, Roy. Med. and Chir. Soc, January 22nd, 1885. 64 PHYSIOLOGY OF NERVES. its appearance wlieii the narrowing has reduced the process almost to the width of the fibre. This medullary sheath begins in the layer of protoplasm which surrounds the axis within the neurilemma, and which can be traced, lessening as the myelin increases, for some distance. Probably it does not entirely cease on either side of the myelin (see p. 59). Thus, in the meduUated fibres there is a continuity with the ceU of the axis, the neurilemma, and probably the protoplasm, and this continuity proceeds from the fact that the fibre is by development a part of the cell ; while it is moreover found to be so vitally, throughout life. It shares all modifications in the nutrition of the cell, never preserving a perfectly normal state if the nutrition of the cell is changed. Tet the relation is less simple than it seemed when the axis was believed to be but an attenuated prolongation of the substance of the ceU. It has been pointed out in the last chapter that the fibrils which constitute the axis pass through the cell and, although they must be considered part of the cell, we are led to look rather to the protoplasm, prolonged along the fibre, for the element of vital integrity — a conclusion in harmony with much elsewhere. The function of nerve-fibreS is seen in a different aspect under the light of the new investigation. As already explained, it was formerly thought that the cells produce and the fibres conduct what is termed ** nerve-energy," although fibres also can generate this when they are stimulated, and cells conduct the impulse that passes through them.* The fact is now seen to be that the nerve-fibrils simply conduct when they pass through the cell-body, as they do elsewhere ; and it is con- spicuous when, for instance, a bundle of fibrils simply skirts the edge of the cell-body at one corner in passing from one process to another, as may occasionally be observed. That which is true of one fibril must be true of all. The relations are too fundamental for the conception of differences. If any fibrila began or ended in the cell- substance, all would do so. If it is true of some, it must be true of all, that the function of the cell is vital nutrition. Where the fibrils begin as such, as conducting structures with the constitution susceptible to the same changes throughout, whether this " beginning " is a change of constitution or of structure — ^there we must look for the source of the energy that is conducted. But we have not yet learned how to look. The division of nerve-fibres where they terminate, as in muscle, or begin, as in the skin, must be regarded as separation or union of axis- * The double similarity of the function of the cells and the fibres was further insisted on in the last edition of this book in words that are worth quoting, because they show how significant are the facts of function as well as of structure: — *'The process of the cell it-^elF must conduct, and the cell must itself conduct. Each motor cell of the cord is part of the path through which the nerve-energy from the brnin passes. That which passes through must be conducted, however it may be chanrred in amount. Even if it is renewed, we cannot so distinguish thia function of the cell from that of the fibre as to say that there is not conduction." LE8I0NS OF NERVES. 65 fibrils or of groups of them. This has been already erplainecl, and other points have been mentioned in the last chapter which concern the action of the nerves, in so far as this can be discerned with distinctness. Lesions of Nerves. — Seconda/ry Degeneration. — A nerve-fibre ■undergoes destructive changes whenever it is separated from the cell from which it springs, i. e. the body of the cell of which it is vitally a part. Formerly, importance was attached to the fact that as a rule the degeneration is in the direction of conduction, i. e. from the cell from which the nerve-fibre conducts nerve-impulses. This must be so because each fibre belongs only to one cell. The fact is, however, conspicuous, because it is only in the long axis-processes that the direction of degeneration can be observed. The short dendrons degenerate from, though they usually conduct towards, the cell-body ; and so also do the long sensory fibres, axis-processes of the cells of the spinal ganglia. These were formerly regarded as inexplicable excep- tions to the correspondence, when the impulses were thought to be produced in the ceU. We can now see that they are instances of the general condition. The degeneration is commonly termed "secondary," because it is dependent on a "primary" lesion of another kind — as division or desti-uction of the cell-body of the nerve. Degeneration also follows many slighter lesions such as nerve compression, transient or exten- sive, or local inflammation and the like ; and this may differ only in degree from that which follows division. It must be more than a difference of degree, however, when there is no recovery. The secondary degeneration is often called " Wallerian," from the name of the pathologist who first studied it. It is of great importance practi- cally and theoretically. The medullary sheath breaks up into segments, and these into smaller and smaller fragments, and the minute globules and granules are ultimately removed from the nerve- sheath, and when the degeneration is complete the axis-cylinder also perishes. The process is not one of mere decay, but is an active one in which the nuclei of the fibre, and their protoplasm, assume an exuberant energy of growth, while the protecting myelin sheath and the essential conducting axis perish, apparently at the same time. In connection with this it may be remembered that in the central organs, the connective tissue overgrows as sclerosis when the fibres decay. Developmental relations justify us in connecting the two sets of facts. In all organs, indeed, we can perceive the fact, though most clearly in the nerve- structures, that "parenchymatous " decay and adventitial growth go hand in hand. In nerve-fibres the aspect of the process of degeneration can be better perceived than in any other structn.es, and it has been carefully etudied in animals, chiefly by Eanvier. The most important facts are illustrated in Fig. 33, in which the examples have been selected from Ranvier's figures and reduced to one tint. First of all the nuclei are increased in size (A n, B w) ; the amount of protoplasm about VOL. 1. 5 66 LESIONS OP NERVES. them is greater than normal, and is granular; there is in places a local increase in the amount of protoplasm within the sheath, com- Fia. 33. Fig. 34. Ifi Pig. 33. — A-J, degeneration of nerve-fibres (osraic acid and carmine staining). A, from sciatic of rabbit four days ufter section ; B, C. same, fifty hours atter section ; D, a fibre stained with carmine only, to show the axis- cylinder; E, F, G, fibres from pigeon three days after section; H, two fibres from pneumogastric of rabbit six days after section; J, a lymphatic cell from interstitial connective tissue, containing globules of myelin which it has taken up. In all the figures— n, n, nuclei ; x, x, constrictions of the mvolin produced by the growth of the protoplasm ; ao, axis- cylinder, "K, L, regeneration of nerve-fibres. K, from pneumogastric of rabbit se^ eiitytwo days after section ; L, from sciatic of rabbit ninety days after section; e, rounded end of white substance of central end of nerve; #, sheath; na, new axis-cylinder. In L are two globules of myelin remaining from the degeneration of the old fibre. Fig. 34. — Degenerating fibres from cutaneous nerves of man. (After Pifres and Vailltnd.) A, from near a bedsore in a case of fracture of the skull ; B, C, D, from the fifth nerve in a case of neuralgia and ulceration of the lip; n, n, nuclei. In A the protoplasm and nuclei are increased, and the myelin is breaking up, the processes liaving ])roceeded furthest in the neighbourhood of the nucleus in the middle of the fibre ; in B the segmenta- tion has gone on to the formation of globules, which in C are, for tlie most part, small, and many have been removed, so that the fibre is narrow; while in D all the products of degeneration have been removed from con- siderable tracts of the sheath, pressing the myelin (A x,B x,G x). The nuclei then become detached from the sheath ; the protoplasm everywhere increases, and encroaches on the myeUn, until here and there it meets across the tube, com- GLNERAL PATHOLOGY. 67 pletely separating tlie myelin (A, lower part ; B, upper part), and "with the myelin the axis-cylinder (D). This process then goes on with increased rapidity ; the myelin is broken up into smaller and smaller fragments (C, E, P), which become globular in the watery protoplasm, just as oil forms globules in water. The nuclei meanwhile continue to enlarge, and then divide, first the nucleolus and then the whole nucleus (F). The two nuclei may again divide, until (as in Gr) there are four or more nuclei ia each intemode, instead of one only as in health. The small globules of fatty myelin seem to become changed in chemical composition, since they are stained less deeply by osmic acid. Ranvier suggests that their fatty matter may undergo a process of saponification. Ultimately they seem to pass through the sheath, are taken up by con- nective-tissue cells and lymphatic cells in the vicinity (as in J), and are gradually, for the most part, removed. By the time the myelin is in small globules the nuclei cease to multiply. On the removal of the products of degeneration the sheath shrinks, and looks empty in places ; but here and there it is enlarged by the nuclei, protoplasm, and a few remaining myelin globules (H). Hence in transverse section many small sheaths are seen, with a few of larger size where they have been cut across at these swellings. In the rabbit the first changes are visible at the end of twenty-four hours ; the first complete interruption of the myelin and axis-cylinder occurs about the end of the second day ; the process of destruction is considerably advanced at the end of the fourth day, and is finished, and the multiplication of the nuclei ceases, towards the end of the second week. In peripheral nerves the changes seem to progress from the lesion to the periphery, but within the central nervous system they are said to begin at the same time in all parts of the fibre. It is uncertain to what extent this difference is real or is only apparent, but the process goes on most rapidly at the periphery. At the end of the second day, in the rabbit, stimulation of the nerve by electricity below the lesion no longer causes muscular con- traction, the disappearance of electrical excitability coinciding with the first complete segmentation of the myelin and axis-cylinder. A curious fact, imfortunately more interesting in pathology than in practice, is that the degeneration of a divided nerve does not occur if the ends are brought quickly into perfect apposition. It is so in animals, and probably also in man.* Immediate replacement may occur in some incised wounds, and thus the fact is explained that simple division is a less serious injury than a grave contusion. The axis-cylinder seems thus to undergo these changes as a whole, although we know that it is a group of fibrils. But we have seen that the conducting substance of these fibrils, and that which separates it (and may be conceived as analogous to the myelin around the whole axis-cylinder), differ but slightly in consistence. Both are nearly fluid, • See Bowlby, ' Injuries and Diseases of Nerves,' p. 32. 68 LESIONS OP NERVES. and so break up into globules, although they differ in constitution in a manner and degree that subserve entire difference in function, and permit reagents to produce artificial differences in aspect and cha- racters misleading if simply transferred to the living state, and yet the revelation of an essential difference of absolute importance. The process is thus the result of an active growth of the nuclei and protoplasm of the nerve, i. e. of the cellular elements of which the nei-ve is composed. Why does this occur ? The determining cause is the interruption of the continuity with the cell-body or the destruction of this. Ranvier connects the destructive growth of the protoplasm with the loss of function in the axis, and suggests that normally the activity of this restrains the vital energy of the cell-elements. These changes are often attended with others outside the fibres, such as we regard as evidence of inflammation. Several observers have describedv increase of nuclei and accumulation of leucocytes in the interstitial connective tissue, and even in the nerve-sheath, with dilatation of the blood-vessels. Such changes are, indeed, intense at the primary lesion ; their degree in the nerve below the lesion varies and seems to be proportioned to that in the primary process. This is another mode of statiuL,' the important fact that the irritative character of the secondary process is determined by the irritative nature of the primary disease. We may say, if we like, that in the slighter degrees it is distinctly inflammatory in aspect in proportion to the signs of inflammation at the primary lesion. But this is only another mode of stating one part of the general fact, and the importance of the transmis- sion of the character of the process cannot be too strongly insisted on. The process of secondary degeneration occixrs more slowly in the rabbit than in a bird, and seems to be still slower ia man, in whom it is probable that complete segmentation does not occur until between the fourth and eighth days. It is certain than an identical process occurs in man. Changes in peripheral nerves near bedsores and in the fifth nerve, found by Pitres and Vaillard, are shown in Fig. 34, a comparison of which with Fig. 33 will show the identity of the process. It is highly probable that after complete division of a nerve in man the changes are the same as in animals. But the most common lesion is, or involves, inflammation, and the process of degeneration is thus greatly modified by the character of the primary lesion, and in time as well as in character. In the latter cases, which are chiefly those of focal neuritis, the process cannot be the same as that which follows sec- tion of a nerve. The change in irritability, which will be more fully described in the account of the symptoms, is a slow depression, some- times moderate in degree. The depression may be preceded by an increase in irritability. In such cases there can be no complete seg- mentation of the nerve-fibres. There must be a gradual alteration in the molecular nutrition of the axis-cylinder, changing its excitability. Even in severe cases there is not usually a sudden loss of irrita- bility ; the current necessary for stimidation has to be made stronger, GENERAL PATHOLOGY. Q'J until at last in seven or eight days the strongest endurable current fails to cause muscular contraction. But we cannot infer, from this alone, that there is an actual interruption of the axis-cylinder. A stronger current might still excite the nerve, because, as we shall presently see, when a nerve is being regenerated, an axis-cylinder may conduct, and still not be excitable by currents of ordinary strength. All severe changes in the nutrition of the fibres involve the intra- muscular nerve-endings in the same degree.* The evidence of this is that the faradic irritability of the muscles (which depends on the nerves within them) presents changes quite similar to those of the nerve-trunk. But this is not always true in slight changes of nutrition of the nerve. We shall presently see that the slight alterations of irri- tability in the nerve and muscle do not always correspond. The nerves terminate in structures of special nature, and these may well have some shght degree of nutritional independence. These secondary destructive changes occur in the peripheral part of the divided nerve. But the part that remains continuous with the cell does not always preserve a normal state. Changes occur in it, espe- cially near the lesion, which are still the subject of study, and of which more must be known before their significance can be determined. In a divided nerve the changes, which are mainly those of ordinary, often incomplete, degeneration in isolated axis-cylinders, affect the centripetal (sensory) fibres far more extensively than the centrifugal. Later on the cells connected with both suffer, the nucleus shrinking and the protoplasm to some extent becoming disintegrated.f Regeneration may occur in the nerve after the degeneration is over. It is a slow process, occupying the second, third, and fourth month after division. According to Eanvier, and as Waller thought, it occurs always by the growth of new axis-cylinders from the central end of the nerve (see Fig. 33, K and L), which ultimately become covered with myelin. One or more new fibres may spring from each central fibre, and these may subdivide. All are enclosed in a sheath which is con- tinuous with that of the central end (Fig. 33, K, «.) . We must assume that only some of these ax is- cylinders persist and achieve functional permanence. But the whole of this subject needs re-investigation in the light of the multiple constitution of the axis-cylinder. J Some- times these fibres twist about, and even turn back and grow upwards, probably in the direction of least resistance. In animals new fibres • Fully described and figured by Babes and Mariiiesco, 'Babes' A tins Path. Ilistol. des Nervensystems,' part 5. t SeeHomen, ' Ziegler's Beitrage,' viii, and 'Babes' Atlas,' part 2. R. A. Fleming (' Brit. Med. Journ.,' 1896, ii, p. 918) lays great stress on the degeneration of the fine (vaso-motor ?) fibres above the lesion, and describes also a considerable con- nective-tissue overgrowth in the same part. X The precise renewal of these fibrillary conducting paths cannot be ascertained in animals, and in man the amount of damage that is renewed is far smaller. Facts are needed regarding minute differential localisation after recovery from an injury, compared with the normal. 70 LESIONS OP NERVES. may grow throtigli a consideraLle extent of cicatricial tissue between the divided ends of a nerve, but in man it is doubtful wbetlier regene- ration of a divided nerve occurs unless tbe extremities are brought in contact, or at least close proximity. Some investigators believe that there is a formation of fibres in the peripheral extremity independ- ently of the growth of new fibres from the central end.* In cases of slight injury, regeneration occurs more readily ; in these it is probable, as we have just seen, that degeneration has been incomplete. The regenerated nerve- fibres regain some conducting power while they are still much narrower than normal, and before they can be excited by electricity.f Muscles. — The degeneration of the motor nerves is attended by changes in the nutrition of the muscles. These commence in or after the second week. The muscular fibres become narrower, and may be reduced, ultimately, to one third of their former width. An increase in width has been said to precede the narrowing for a few days. J The transverse striation becomes less distinct, and the striae seem to be nearer together than in health. The fibres may become cloudy or granular, but do not present actual fatty degeneration except in some very acute cases. If no regeneration of the nerve takes place, the transverse striation gradually disappears, and may be replaced by a longitudinal striation, or the fibres may undergo certain chemical changes, and pre- sent a peculiar glassy appearance, which has been called "vitreous * a. g. Neumann, Mayer, &c. A full abstract of their observations is given by Bowiby (loc. cit.), and also by Allen Starr in the Middletpn Goldsmith Lectures for 1887 (' New Yoi k Med. Record,' Febrdary, 1887). By some the new axis- cylinders are said to be formed by elongation of the fragments of the old axis ; by others from the nuclei of the sheath of Schwann, but these have been found by others to take no part in regeneration (von Notthaft, see below). But Ranvier'a careful investigations have been fully confirmed by the minute researches of Vanlair (* Arch, de Biologic,' 1885), and by the more recent experiments of Stroelie .(* Ziegler's Beitrage,* 1893), and it is difficult to understand that perfect axis- cyliu'iers should be formed and remain unexcitable, as the peripheral segmeut certainly does. Structures may be formed resembling axis-cylinders that are nob really capable of the proper function. The weight of Ranvier's undisproved and confirmed observations is very great. His conclusion that there is no discontinuous formation of fibres has been also confirmed by von Nottliaft (' Zeitsch. f. Zool.,' 1892, Bd. Iv). It is possible that the process, in the peripheral part of a nerve, is influenced by the connection with other nerves and the recurrent influence of anastomosing fibres. t Ziegler, in a recent paper ('Arch. f. klin. Chirurg.,' 1896), reasserts the ahan- doned view that the old axis-cylinder plays no part in regeneration, the active agent in whli-,h is a nucleated protoplasm which he states to be an outgrowth of the sheatl: of Scliwann (this probably refers to the protoplasm mentioned on p. 51). F'l-oiji this he describes the development of a primary protoplasmic fibre, from wliich are differentiated not only a new axis-cylinder but also a new sheath of Schwann and medullary substance. This new axis-cylinder is ultimately joined to the old stump. These statements have not as yet received confirmation by other observers. J Steinert, ' Verb. Phys. Ges. Wurzburg,' 1888, No. 10. SYMPTOMS. 71 U generation." During the progress of the changes in the fibres, the nuclei of the sarcolemma and of the interstitial tissue are increased in number, and develop into fibrous tissue, so that ultimately the muscular fibres are separated by considerable tracts of connective tissue, and a state of cirrhosis results. If regeneration of the nerve occurs the muscular changes are arrested, and the normal condition is slowly re- stored. When recovery of the nerve is slow, and the secondary process in the muscle considerable, the fibres remain small, the amount of con- nective tissue is permanently increased, but undergoes contraction, so that the muscle is for a long time smaller than normal, and its natural bullc may never be regained. If no regeneration of the nerve occurs, the muscular fibres gradually disappear ; fibrous tissue takes their place, and, slowly contracting, permanent shortening may result. Similar shortening sometimes occurs when there is partial recovery of the nerve and muscle. In most lesions of nerves, other than actual division, some fibres recover, even though others are permanently destroyed. The muscular degeneration is the result of that of the motor nerves, as described at pp. 66, 67. Symptoms of Neeve Injury and Degeneration. — The symptoms that attend the lesions of motor nerves and the consequent degene- ration are of great importance. The lesion of the nerve causes para- lysis of the muscles supplied by it, due to, and in proportion to, the interference with the conductiag power of the nerve. The WEEKS I M N >..sM'^"'~ \\ ' iiiiiil IIIIMIIIIIIIIIIKIIIIIIIIIIMIIIIIKJ Pig. 35. — Type of degenerative reaction in a case of nerve-ininry of inode- rate severity. (After Erb.) Muscle irritability lowered from middle of first wreek ; faradic, extinct in middle oF third, reappearing in ninth; voltaic, increased from middle of second week until tenth, then de- pressed until t'onrteenth. Nerve irritability (changed alike to both currents) is lowered from middle of first week, lost Ht end of second, reappearing at seventh. Power lost until end of fifth week. tnuscles at once become flabby from loss of tone, and to this atony actual wasting is added in the course of a few weeks. The wasting is due to the reduction in size of the muscular fibres. If the sensory nerve-fibres are not interrupted, the muscles become tender to the touch, and pain is caused by their strong contraction, due probably to the effect of interstitial inflammation on the sensory nerves, which end in the connective tissue. The most important symptoms are those that are afforded by elec- 72 LESIONS OF SERVES. trical examination of the muscles and nerves, since they enable the degeneratiye changes to be ascertained and followed during life.* The alterations in the electrical reaction, consequent on this degeneration, have been already briefly mentioned (p. 29), but must now be described in greater detail. The rapid degeneration of a nerve, which follows a severe lesion, is attended by a loss of irritability on electrical stimula- tion, the loss being the same to faradism and voltaism. After such lesions as are common in man — neuritis, for instance, — there is no sudden loss, such as occurs after injury of a nerve in an animal, when the nerve becomes segmented, but there is a more or less rapid diminution of excitability, and this goes on until no stimulation can be produced, even by a strong current. The progressive changes in irritability may be conveniently represented on a chart. Fig. 35 shows the typical course of the changes of irritability in a case of moderate severity. In the muscle (M) a fall of irritability (due to the degeneration in the nerve-endings) occurs simultaneously with that in the nerve-trunk (N), and the f aradic excitability becomes extinct at the same time in both nerve and muscle. The fall in voltaic irritability is quickly arrested by the change in the muscular fibres, through which they soon become more excitable than normal to the voltaic current. This change usually occurs during the second week, and the irritability continues to increase during the third and fourth weeks. At its maximum it may amount to three, four, or five cells of the battery, i. e. contraction can be obtained in the paralysed muscles with a current weaker by so many cells than is necessary to cause contraction in a corresponding un- affected part. The further course of the changes in irritability depends on the severity of the lesion and the intensity of the degeneration. In a case of moderate degree, such as is shown on the chart, nerve irrita- bility reappears about the end of the second month, usually after some voluntary power is regained. It is at first low, so that a strong current is required. It gradually increases, but for a long time continues a little below the normal degree. This return of nerve irritability is accompanied by a corresponding return of faradic irritabiUty in the muscles (i.e. in the intra-muscular nerves). The increase of voltaic irritability often persists long after recovery of power, but it lessens as faradic irritability returns, and, as shown in the chart, it may fall below the normal before it ultimately regains its original degree. Slight changes in irritability can be ascertained only by a comparison with the corresponding part on the other side in the same individual. Moreover, when we speak of excitability being " lost," we mean that we can obtain no stimulation by any strength of current that can be borne. The sensitiveness of the skin varies in different j^ersons and in different parts. The resistance of the skin also varies ; the greater it is * For !i careful analysis of abnormal electrical reactions in muscle and nerve see Douiner, ' Bulletin Offic. de la Soc. fran9. d'Electrotherapie,* 1897. The author lays especial stress on the importance of recording the nature of the excitation and the character of ihe muscle-curve produced. SYMPTOMS. 73 the stronger must be the current used to secure the action on the nerves below. Hence the importance of ascertaining what current is actually- passing by the use of a galvanometer. It may be used once to gain in- formation as to the significance of the number of cells that constitutes the evidence of the difference between the two sides when the sensitive- ness to the pain which is caused prevents the use of the instrument in all measurements. If the lesion is very severe, so that there is no recovery, and no re- generation of the nerve, the loss of nerve irritability, and of the faradic muscular irritability, is permanent. The increase in voltaic irritability persists for months, and then gradually falls as the muscular fibres waste, and becomes lower and lower (see Fig. 36), WEEK^r 3 10 20 30 40 50 60 70 eo 90 :.-. M •.F 'V -~-i: Icnc: r-^wu-i; ■'-■ c N ■•% r\oTpuiJk line^ P Pig. 36. — Type of reaction in a case of complete and permanent damage to a nerve. (After Erb.) Early course as in the last diagram; no return of power, nerve irritability, or faradic irritability in the muscle. The early increase in voltaic irritability gradually lessens, and at the end of ten months falls below the normal, but is not extinct until nearly two years. In this and the foUowina: figures the normal degree of irritability (ascer- tniiied from the healthy side) is represented by the finely dotted horizontal line (w.^.) ; faradic irritability, P, by a line of larger dots; voltaic irritability, V, by a broken line; M, muscle; N, nerve; P, power of voluntary contraction, its degree shown by the vertical lines; the asterisk marks the occurrence of the lesion. The vertical divisions represent time intervals. (Many of these indicating letters are given only in subsequent figures.) until ultimately no reaction can be obtained, the fibres having perished. It does not become extinct until at least a year has elapsed, and some- times (as in the chart) only towards the end of the second year. Often, when no contraction can be produced on the first attempt, after two or three applications, distinct contractions are obtained. The changes we have hitherto considered are in the degree of irrita- bility, " quantitative " changes. But the quantitative increase in the muscular irritability is often accompanied by a change in the order of response, according to the pole that is applied and the strength of current — a " qualitative" or "polar" change. We have already con- sidered its general characters (p. 31), and have seen that it consists in an undue readiness of response at the positive pole (anode) com- pared with that at the negative poll (kathode) (Fig. 37, B and C), the muscle being normally the more sensitive to the latter (Fig. 37, A). Writing CI. for the closure of the circuit, 0. for its opening, and C. for contraction, the normal reaction is — 74 LESIONS OF NERVES. 1. K.CLC. ; 2. {;^^Q^^-.' 3. K.0.0. In disease — 1. I f ^^q^q' . 2. An.O.C. ; 3. K.O.C. : or even 1. An.Cl.C; 2. KCl.C. ; 3. K.O.C; 4. An.O.C. Tliis qualitative change is at times absent, especially in cases of neuritis. It may be slight, and only amount to an equal kathodal and anodal excitability. It is practically constant when a nerve has been actually destroyed. On the other hand, it may be present and significant where less acute disease has not yet caused obtrusive wasting. Even when there is a marked quantitative change, the kathodal closure contraction may still occur first. When the change is present it is only in the muscles, and it must depend on the muscular fibres themselves. In the motor nerve the kathodal response is always the first, although a qualitative change has been detected in degenerated sensory nerves. The muscular contractions which occur thus with undue readiness differ from normal contractions, excited through the nerves, in their distinctly deliberate character. Instead of the quick, lightning-like Ka An Ka An Ka Art Ka An Ko. Ai Fig. 37. — Tracings of the muscular contractions in nerve degeneration. (After Erb.) Ka, katliodal closure contraction; An, anodal closure contraction. A, tracing in liealth; Ka nouch stronger than An; contractions sudden. B, tracing in nerve-degeneration with moderate current. An much greater than Ka, the latter scarcely visible. Contraction slower, shown by the more sloping upstroke. C, the same, with a stronger current. Ka greater, but still less than An ; the slow character of the contraction and its long duration well marked. contraction, the movement is distinctly longer in reaching its maximum and longer in its duration. The recognition of this feature is easy, and often of practical importance when there is doubt whether tlie SYMPTOMS. 75 voltaic current is acting through the nerve-twigs, or on the muscular fibres themselves. Sometimes a slight abnormal tetanic contraction during the passage of the current also occurs. During the period of increased voltaic irritability the mechanical excitability of the fibres is often increased. If they are directly percussed, they respond with a distinct slow contraction (Erb). Such are the changes in irritability which occur in cases of nerve- lesion and degeneration of moderate and considerable degrees of severity. Certain variations are occasionally met with, and these occur especially in cases of neuritis of slight degree. In severe cases the fall in nerve irritability, which usually commences in the middle of the first week, may not take place until the end of this week, although it may then progress so rapidly that no response to stimulation can be obtained at the end of the second week. An example of this is shown in Fig. 38.* The same chart, and some of those that follow it, illus- trate another veiy common variation from the type above described. There may be no fall in the voltaic excitability of the muscles before the commencement of the degenerative increase. Indeed, this initial fall is as often absent as present. The change in the nutrition of the muscle may then coincide with, instead of succeeding, the degeneration of the nerve-endings (Figs. 38, 40). Sometimes, if the degeneration is rapid, there is an interval of a few days before the secondary changes Fig. 38. Fig. 39. WK5. I 2 3 [».-r.<»' **. n-i ....nj.. P NONE. M »t? ^^ .,'- — — --- -- ... .,- ^ — *♦.. .., .., • • • 4 ' •• N •'" •iV ''•"t .^_ •~-s '^i-. -.n ■Ti P_ iriU ua Uii m 1 n JLU ill ILl JIL ILU jiiJ ill nil Fig. 38. — Severe neuritis, paralysis complete for months j recovery imper- fect, liritability of nerve normal during first week; fell rapidly during the second ; lost at its close. Simultaneous increase in voltaic irritability. The divisions on the left side represent cells of the voltaic battery, and half- centimetres of tlie secondary coil of St5hrer*s induction apparatus, in this and tlie following charts. Fig. 39.— Slight neuritis; slight return of power on seventh day,'slowly in- creasing; I'.ormal in fifth week. Muscle: faradic irritHhih'ty lessening fmm fourth diiy, lost on fifteenth, reappearing on twentieth. Voltaic irritability normal till twelfth day, then augmented. >erve-trunk: lowered from fourth day without in tial increase, reappearing on twenty-third day; changed alike to faritdism and voltaism. in the muscle have reached the degree necessary to produce increased irritability. In a slight degree of degeneration the increase in the voltaic irritability of the muscles may be postponed for a week or more after the nerve irritability begins to fall, and until the rise occurs the • This and the following charts are from cases of neuritis of the facial nerve. 76 LESIONS OP NERVES. voltaic irritability of tHe muscles may remain normal, eren when tlieir faradic irritability falls with that of the nerve-tnmk. An instance of this is shown in Fig. 39. When the nerve-lesion is very slight in degree, the fall in nerve irrita- bility may be preceded by a rise, which may be far greater in degree than the subsequent fall. In slight cases the fall may indeed be not only slight, it may be altogether absent, so that the rise consti- tutes the only symptom. This initial increase in irritability is important as the manifestation of the slightest degree of altera- tion in the nutrition of nerve- FlG. 40. — Slight neuritis; power not entirely fibres.* It may last for a feW lost, and becoming normal during the ^ f ^ j^ ^j,- ^q. third week. Shght deg- react, m muscle •' >. o /» developed during second week, and con- and I have once known it to con- tinued till seventh. Nerve irritability tinue for five weeks (Fig. 41). increased during second week, passing . ,, . , .-, , • • •. during the third into transient depres- Although the change^ m imta- sion, tlie voltaic irritability falling more bility of the nerve is usually than the faradic. ^j^g ^^^^^^ ^o both currents, a partial exception to this rule is presented by the increase in irritability we are now considering. The change is not always quite equal to WKSt 2 3 4 6 6 7 6 9 «0 '» II 1^ 14 lg »6 17 IB '9 ^ A/KS. ' f ^ 4-56: A ZHX I N :•;;•'- ::;v: ,..._.,, ■-.:■:: ■"=- nress ': N •■*■< ;:;:: .'Vvi ■ttSJi it^-'A tiVJ ii4t»- p UJIIlil llllill iiii UlU N M Fig. 41. — Slight neuritis; quick recovery of power during third and fourth weeUs. Degen. react, in muscles present at the end of the second week, slowly lessening, but present in slight degree until the fourth month. Considerable increase in irritability in the nerve-trunk at the end of the sopnnd week, greatest to the faradic shock (crosses), and lasting until the fii'th week. faradism and to voltaism, and it is frequently much more marked to the isolated faradic shocks than it is to either the voltaic current or the rapid succession of shocks that constitutes the faradic current. This is shown very strikingly in Fig. 41, and in less degree in Fig. 43. In the former the irritability to the two currents was the same ; in the latter that to voltaism was distinctly the greater. I have once met with a slight but distinct and prolonged diminution in faradic irrita- bility when no change could be found to voltaism (see Fig. 42). * A similar change is met with in some central di^seases, aa chorea and paralysis agitaua. SYMPTOMS. 77 Lessened irritability to faradism with distinct increase to voltaism has been observed in an ulnar nerve, the seat of traumatic paralysis (Bernhardt). In one case of extensive peripheral neuritis of obscure toxic origin, in which the face on both sides was paralysed for a time — a peculiar nutritional change in the nerves, where the action of the Fig. 42. WEfKS 1 X 3 4^^ 5 6 7 Fig. 43. DAYSx 4- 6 8 10 ft 14 Tent tiar ;•;•;•;■ •;•;•;■. '•'■*■•• .-.. EN — ■M.^. — — .— ,_ ., ...... ..* — v.- ~ : P UUUIUSJ UllJII IHIIII Ill III M :_??7. L„. \T,rt i7r* -fi •ar -.I- M ■~\- w^ .'S.t •tf '^V %■% 7i< P ^ iUi Uil aii Fig. 42. — Slight neuritis : power regained dnving the second week, Deg. react, in muscle distinct on eighth day, lessening during second and third weeks. Nerve: lowered fai'adic, normal voltaic irritahility. Fig. 43. — Very slight neuritis. No change in muscular irritability ; irri- tability of nerve-trunk increased from fourth to eighth day, most to faradic shock (crosses), least to far.idic current. toxic agent was less than at their extremities, and made the nerves in- sensitive to the momentary induced current, — the voltaic excitability of the facial nerves was not lessened, although faradic irritability was lost to such a current as could be borne. The electrical excitability of a nerve and its power of conduction are usually lost together. But when a nerve is recovering from a local lesion, and regeneration is in progress below, some power of conducting the impulse that is excited above the lesion may return in the peripheral portion before it becomes excitable by any form of electricity. This is true of the impulse from the brain, and that excited by electricity. This seems to show that the nerve-fibres can conduct — that is, pass on the nerve-force they receive as such, before they can produce nerve-energy in response to the influence of a " stimulating " force acting on them. Another rare anomalous condition has been noted by Bernhardt and G-rUnberg in cases of recent nerve injury. When the lesion arrests all conduction of the voluntary stimulus a strong faradic stimtdation of the nerve above the lesion may still cause slight contraction in the paralysed muscles. Recovery of the nerve is attended by gradual restoration of power over the muscles, the nutrition of which slowly improves ; but if the wasting has been considerable, a long time elapses before they regain their normal size. Indeed, as already stated, they may be always somewhat smaller than the corresponding muscles on the unaffected side. Curious secondary spasmodic symptoms are common after palsy of the facial nerve (q.v.) — contractures, spontaneous contractions, and associated over-action of different muscles. The last is very rarely met with after palsy of the nerves of the limbs, but coarse, fibrillary. 78 LESIONS OF NEHVES. muscular contractions, and a tendency to cramp, are not uncommon, and may persist for years. (See also Neuritis.) Sensory symptoms also result from lesions of the nerves that contain sensory fibres. The interruption of the fibres arrests conduction, and causes loss of sensation in the part supplied by the nerve, just as it causes motor palsy. But a slight lesion of a mixed nerve may cause persistent muscular paralysis, and sensation be unaffected, or impaired only in slight degree and for a short time. This restdt is so frequent that we cannot ascribe it to a dilference in the relative damage to the motor and sensory fibres. It must be due either to the fact that the sensory fibres recover more readily, or that a slight degree of conduction may suffice for the stimulation of the sensory centres in the brain, and not for that of the muscular fibres. There is also a third hypothesis, and that is a difference in the sensory and motor impulses in physio- logical character.* In another class of cases, however, we must seek a different explanation of the persistence of sensibility in the area supplied by the nerve. There may be no loss even when a nerve is completely divided. This is observed chiefly near the extremity of a limb. It can only be explained by what is termed " recurrent sen- sibility." Anastomoses exist between the terminal fibres of different nerve-trunks, and it would seem that this contiguity of sensory fibres suffices for conduction. Individual differences are seen to exist in this. Thus, of two persons in whom the ulnar nerve at the wrist has been divided, one may have total anaesthesia in the fingers supplied by the nerve, and in the other there may be little or no loss. The peripheral segments of the sensory fibres degenerate, like the motor nerves. We cannot test them, and ascertain the degeneration in the same way, at least in severe lesions, because their stimulation cannot be perceived. Nevertheless an altered polar reaction has been observed in slight cases, analogous to that which occurs in the muscles. A sensation is produced with the positive voltaic pole by a weaker cm-rent than is required with the negative pole. In some cases of nerve injury and neuritis a delay in conduction of pain may be observed. Increased and disordered sensitiveness in the area of distribution of the nerve, with or without spontaneous pain, is very common in cases of partial lesions of nerves. It must be referred to the morbid changes in their fibres, alterations in the nutrition of the axis-cylinder or nerve- endings, probably analogous to the slight changes in the motor nerves which increase their excitability. Pain and tenderness of the nerve- trunk are also frequent in the same cases, due no doubt to the increased sensitiveness of the " nervi nervorum " distributed in the sheath. The sheath of each nerve is part of the dis+ ribution of its own fibres, and those that end in the sheath seem lu be very readUy deranged. We shall see the importance of this consideration in relation to neuritis and * Tlie experiments of Lenderitz (' Zeitschr. f. klin. Med.,' Bd. iii) merely confirm the observed fact, and do not really explain it, as he and others have assumed. SYMPTOMS, 79 neuralgia. The pains, botli local and distant, are sometimes very severe and persistent. Reflex Action.-'— AR lesions of nerves abolish reflex action in the area of the distribution of the nerve affected, except those that involve so shght a change as to cause increased sensitiveness, Mjotatic irri- tability is also lost, f lom damage to either the motor or sensoiy- fibres concerned, and this loss may persist long after the other symptoms. Vaso-motor and trophic disturbance is a common consequence of lesions of nerves. It is most severe in those that are inflammatory in part or altogether. The vaso-motor nerves run in the mixed nerve- trunks, and suffer with the other fibres. The general character of the disturbance has already been described (p. 27). When the lesion is acute and irritative, vascular dilatation and an increase of temperatiu-e occur at first, and are followed by passive hyperaemia and lowered tem- perature. There may be oedema, and an increased secretion of sweat. The changes in the skin, acute and chronic, are those that have been already described. " G-lossy skin," red, smooth, and thin, is especially common, and is frequently accompanied by atrophy of the subcutaneous tissue, and pei-haps of the bone, so that the finger-tips become narrow, and present an aspect that is very characteristic. Burning pain, with tenderness, often accompanies the change, and may continue for long. Occasionally, instead of becoming thin, the epidermis increases in thickness, the nails often become thick and rough, and present trans- verse or longitudinal furrows.* In parts where there is much sub- cutaneous tissue this may also become thickened and have a peculiar doughy feel, resembling that met with in myxoedema. The growth of the hair may be lessened or increased. Sloughing of the skin is far less common than in central diseases, but eruptions, particularly of the nature of erythema, eczema, herpes and pemphigus, may also be met with. Vesication occurs with extreme readiness, and sometimes vesicles or bullae appear to form spontaneously. Ulcers result which erode and destroy the tissues, especially of the finger-ends. Mustard plasters also blister the skin more readily than in health. It is im- portant to remember these facts, because the affection is one in which hot applications are often recommended. A gentleman dislocated his shouldei-, and either by the displaced bone, or in the reduction, the brachial plexus was seriously injured. The muscles of the hand wasted, and the skin became glossy. He was advised by a surgeon to bathe the hand daily in hot water. One day his wife bathed it in water which to her was pleasantly warm, and which caused him no discomfort, but the result was that the hand was covered with bhsters, and ulcers were left which did not heal for months. * Several excellent illustrations of these changes iire given by BowUiy, loc. cit., where also a full account of traumatic lesions is given. The observations of Beru- harlt ('Viichow's Archiv,' 1886) appear to show that the retarded growth of the nails is independent of the influence of the particular nerves. Great individual Tariatioiis are found with identical lesions. 80 COMPRESSION. The joints often suffer in their nutrition. Acute inflammation, such as occurs sometimes in spinal affections, is rare, but chronic changes in the joints are frequent, with much tenderness; alterations in the articular surfaces, and fibrous adhesions result, which limit movement. When the muscular wasting is slight, the condition may resemble a pri- mary .joint affection, and this mistake in diagnosis is sometimes actually made. INJURIES OF NERVES: COMPRESSION. Traumatic lesions of nerves are in the province of surgery. They belong to the physician only in so far as their effects are produced by the agency of a neuritis, the mechanical origin of which may escape notice. Neuritis is described in the next section. A word is needed, however, on the subject of simple, slow compression of nerves, not because the symptoms are grave, but because they often give rise to very grave mental concern on the part of the patient, and to occa- sional doubts in the mind of his medical attendant. Compression of a nerve may be sudden or slow. Sudden compression bruises the nerve-fibres, prodacing definite lesions, and also sets up neuritis. Symptoms often occur too soon to be explicable as neuritic. A slight degree of these is familiar as a result of pressure on the sciatic nerve in the act of sitting. There is first tingling in the region of distribution of its fibres, often with a sense of warmth, with disordered sensations and even a loss of sensibility in the sMn. Often this is accompanied by an inability properly to put in action the muscles that are supplied by the nerve. All the symptoms pass away in a few minutes, a sense of cold and an inability to direct movements being often the last effects. If they do not pass away, the persistent effects are ascribed to a neuritis such as is produced by any other cause. But neuritis is not the primary lesion, and the initial symptoms are not produced by the agency of inflammation. Hence, when they persist, it is doubtful whether we should ascribe them to the inflammation unless they occur after an interval. The mechanism by which the tingling and early anaesthesia are produced, probably causes also the lasting symptoms. The compression no doubt causes anaemia, but the known sensitiveness of nerves to mechanical stimulation makes it probable that the effects are chiefly produced by the mechanical influence of the pressure on the elements of the nerve-fibres, and that a compression for a few hours has such an effect in separating the molecular elements of the white substance, as to set up a secondarv defeneration of the same character as thai which results from division of a nerve. The neuritis is thus no more the cause of symptoms in compression than in division. In each there is a displacement of molecules interrupting conduction. This is also the conclusion of Weir Mitchell, who found that a pressure of eighteen to twenty inches COMPRESSION. 81 of mercmy for twenty seconds abolislied tlie power of conduction, though only for a few minutes, in spite of conspicuous change in the white substance. The latter is still greater, and the effects more enduring, in a contusion. The cause of the tingling in the region of distribution of the sciatic nerve is, as already said, readily recognised when it is due to pressure by sitting. But it is otherwise when the pressure is on the nerves of the arm and is produced during sleep. The tingling may be felt in the region of the ulnar nerve, in consequence of flexion of the elbow, or in the whole hand, from the pressure on the nerves of the brachial plexus on the side on which the patient is lying. Waking up with the tingling, and sometimes with cramp or powerlessness in the hand, he is naturally alarmed. The diagnosis, however, is rendered easy by the unilateral character of the symptoms, and by the fact that they are always felt on the side that is bearing the weight of the body. There may, however, be great dif&culty in diagnosing this form of compression from actual contusions. The symptoms are produced much more readily when the general health is bad; they last longer, and more often end in neuritis. Gradual compression may result from continuous pressure, such as that of a crutch or the growth of an adjacent tumour, or from the implication of the nerve in a cicatrix or callus. Of new growths com- pressing nerves, exostoses and aneurisms are most frequent. The symptoms of this form approach those of neuritis ; they may be sensory, motor or trophic. They are ushered in by hyperassthesia, which is followed by anaesthesia, seldom complete in degree or quality, tactile and muscular sensibility being usually retained when other forms are lost. Intense and persistent hypersesthesia or complete anaesthesia point to neuritis. Motor weakness and trophic changes appear; there may be atrophy or hypertrophy of the nails, trophic ulcers, or joint affections. Among rarer symptoms are local spasm with fibrillary twitchings and reflex convulsions. In simple com- pression the symptoms, as a rule, disappear after the removal of the' cause; the subjective sensations are the first to vanish, then the anaesthesia goes, and lastly — in severe cases not till after some months — ^the motor disturbances. In rapid compression there may be, according to the duration of the injury, merely congestion at the affected spot or peripheral degeneration starting from it. A nerve which has been long compressed is narrow at the affected part, where it may even be flattened into a ribbon ; above and below it is normal or swollen. The compressed portion may be white from anaemia or red from congestion. Eventually degene- rative or neuritic changes may develop, and the former are sometimes found above the lesion as well as below. Treatment is essentially surgical, but the physician must aim at maintaining the nutrition of the muscles by the usual means during the recovery of the nerve, when this can be released from compression. VOL. I. 6 82 NEUiilTlS. INFLAMMATION OF NERVES: NEURITIS. Neuritis, or inflammation of nerves, presents various cliaracters, which have led to the distinction of numerous forms. The inflam- mation of single nerves usually begins in the outer sheath of the nerve, and this has been distinguished as "perineuritis." It may involve also or chiefly the connective tissue between the bundles of nerve-fibres ("interstitial neuritis"), or the nerve-fibres themselves ("parenchy- matous or degenerative neuritis"). Some forms of neuritis have a tendency to ascend the nerve, and this variety has been termed ** ascending neuritis " or " neuritis migrans." One nerve-trunk may be primarily affected, or many nerves may suffer at the same time. The latter condition, " primary multiple neuritis," is of great import- ance, and vdll be described in a separate section. Most forms of neuritis may be either acute or chronic. Acute neuritis usually subsides into a chronic stage, and its symptoms may thus persist for a long time. Other varieties that have been distin- guished depend upon the cause to which the inflammation is secondary. Thus we have cancerous, syphilitic, gouty, diabetic, and other forms. Causes. — Injury causes more or less inflammation, which occurs readily, and follows very slight damage. Neuritis may thus be set up by all sorts of wounds, by contusions, by compression from with- out or by adjacent structures, and by over-extension of the nerves. Those nerves that pass by joints are liable to injury from dislocations, either by the displacement of the bones, or during reduction. In fractures the nerves m.ay be injured directly, or may be compressed by the callus that is formed. Nerves are sometimes damaged by a violent contraction of the muscles through which they pass. It is probable also that muscular effort excites neuritis in other situations, especially in persons who are predisposed. Moreover, a strain on the fibrous tissues of joints, fasciae, &c., may set up inflammation in them, which may spread to the nerves. Neuritis may arise by extension from adjacent inflammation; this is particularly seen in the case of phlebitis. The nerves near suppu- rating joints may be involved, and even, it is said, those that pass by a joint the seat of simple inflammation. The latter is certainly rare. The intercostal nerves have been affected by extension from an in- flamed pleura. The cranial nerves and the spinal nerve-roots are involved by extension from the membranes. Exposure to cold is another cause of neuritis. It is then often called " rheumatic." The nerve, or rather its sheath, may be primarily affected, or the first effect may be inflammation of the fasciae, from which the inflammation spreads to the nerve-sheath. Persons who are liable to muscular rheumatism, and those who are gouty, suffer PATHOLOGiOAL ANATOMY. 83 thus with especial frequency. But exposure to cold and the toxins of gout and rheumatism also act in another way, by causing a blood-state which acts on many nerves at the same time. Many general diseases have a similar power of causing either an isolated or a multiple neuritis. It is through this agency that diphtheritic paralysis is produced, and the same effect may be due to the presence of other toxic material in the blood, metallic poisons, alcohol, &c., an account of which will be found in the section on Multiple Neuritis. When an isolated neuritis occurs during an acute disease it is probably produced through the agency of compression, unnoticed during the prostration. Neuritis has also been found in the vicinity of bedsores (Pitres), and though probably due to pressure may be part of the mechanism by which they are caused. Some chronic general diseases cause only isolated neuritis, — either simple, as that which is due to gout (when the general disease must be regarded chiefly as a pre- disponent) ; or special, as syphilitic, cancerous, or leucocythsemic neuritis, in which there is an infiltration of the nerve with the special tissue-element characteristic of the general disease. The characters of the simple isolated form constitute the chief subject of this section. PathologioaIi Anatomy. — The changes differ according as the inflammation affects primarily the adventitial connective tissue, "adventitial neuritis," or the fibres themselves in the "paren- chymatous" form. Isolated neuritis is generally adventitial, and wiQ be first described. In acute inflammation the affected part of the nerve is red, softened, and swollen. The redness depends on distended vessels, which may be visible on the surface; in more acute cases it may result from the presence of minute haemorrhages. The swelling is due to oedema, or to a sero- fibrinous exudation, sometimes jelly-like in aspect. The micro- scope shows leucocyte-like cor- puscles surrounding the vessels, infiltrating the sheath (Fig. 44) and acc»'iiulating between it and the nerve. There may be even email extravasations of blood. Suppuration is extremely rare. These changes may be limited to the sheath in what is called "perineuritis," or may extend into the substance of the nerve in " interstitial neuritis." In the latter case the lymphoid corpuscles infiltrate the septa, and may even be seen in the substance of the f ascicidi, between the nerve-fibres. These changes Fig. 44. — Neuritis : degeneration of nerve- fibres, the myelin broken up into masses, globules, and granules. Accumulation of leucocytes in uerve-sheath. P'roin a case of multiple neuritis. (After Ley den.) 84 NEURITIS. may be continuous along a considerable tract of tbe nerve (diffuse neuritis), but more frequently they are chiefly marked at certain places, which are separated by portions of the nerve which are so little affected as to appear to the naked eye to be normal ("focal" or "disseminated neuritis"). The foci of inflammation are chiefly situated at places where the nerve turns round a bone, or emerges from canals or fasciae, or divides. The extent to which the nerve-fibres suffer varies much. They usually present little change when the inflammation is limited to the sheath, unless the nerve lies in a bony canal, or in rigid fibrous tissue, within which the sheath cannot expand ; its swelling then exerts pressure on the fibres. When the inflammation is interstitial the fibres suffer more readily, although not invariably. On the other hand, they are sometimes found much altered, when the connective- tissue elements are but little affected. In this case the inflammation is " parenchymatous " and begins in the nerve-fibres, the interstitial tissue being secondarily involved or unaffected. The changes in the fibres are almost the same as in degeneration (Figs. 33 and 34). It was pointed out how closely the two processes of inflammation and degeneration are connected, and how difficult it is to separate, or even to distinguish them, in many cases. The myelin of the white substance first breaks up into segments, more or less elongated, often with smaller globules of myelin between or beside them. The masses are cloudy or finely granular in aspect. The axis-cylinders are inter- rupted where the myelin is divided. The nuclei of the sheath are increased in number, and the protoplasm around them is increased in quantity. Next the myelin is divided into smaller globules and granules, and the axis-cylinder is no longer recognisable. The myelin then disappears in parts of the tubes, while it remains at other parts, but is still more finely divided. Lastly, the sheaths become empty and very narrow, containing only nuclei at intervals, with here and there a little finely granular material, or sometimes some brownish pigment granules. The process may thus go on to complete destruc- tion of the fibres. These commonly suffer unequally; fibres that have a normal appearance are scattered among those that are much altered. In chronic interstitial neuritis the axis-cylinders often suffer less than the white substance. The latter becomes atrophied, so that the fibres are smaller than normal. If the interstitial inflammation is very intense the fibres may break up as above described. As the inflam- mation subsides, the new cellular elements that have made their appearance assume the aspect of fusiform cells, and fibrous tissue is developed, either from these eel';, which become less numerous, or from the intercellular exudation. This fibrous tissue surrounds and encloses the fasciculi, a condition that has been termed " sclerosis of the nerve." A firm fusiform swelling may remain at the affected spot, and this may be adherent to adjacent structures. The axis-cylinders SYMPTOMS. 85 are unequally affected. Those which are involved undergo typical degeneration. Sometimes fat is ultimately formed in the new con- nective tissue, a condition that has been rather unnecessarily termed " lipomatous neuritis " (Leyden) ; the fatty deposit does not seem to be related to any special form of neuritis. Occasionally the connective tissue overgrowth is so extensive that the whole nerve is converted into a sclerotic cord (Virchow's " proliferative " form). In syphilitic neuritis, which affects chiefly the cranial nerves, there is a cellular growth in the sheath and interstitial tissue similar to that which constitutes other syphilitic new formations, with a variable amount of alteration of simpler inflammatory character. The growth in the sheath may amount to a distinct syphilitic tumour, with or without interstitial changes. In cancer, nerves adjacent to the new growth may present simple interstitial neuritis, or may be infiltrated by a gi'owth of cancer-elements spreading to the nerve by direct extension. In leucocythsemia there is a dense infiltration of the nerve with leucocytes. The destructive changes in the nerve-fibres extend down the nerve to the periphery in a process of secondary degeneration, more or less inflammatory in nature, as already described in secondary degeneration. Usually the central portion of the nerve remains free, the alterations ceasing a short distance above the seat of the primary inflammation. In rare cases an ascending neuritis (n. migrans) passes up the nerve, and may spread, at a plexus, to other nerve-bundles and other nerve- trunks. The formation of fibrous tissue in the inflamed part, and the cicatricial contraction of this tissue, often prolong the irritation of the nerve-fibres and the symptoms due to this, and a state of " chronic neuritis " is said to be left. Symptoms. — The symptoms of neuritis vary extremely according to its intensity, its extent, and the nerve that is affected. In three places, the brachial plexus, the sciatic nerve, and the crural nerves, the sym- ptoms are sufficiently special to make their separate description desirable, although the general account applies to them also. The onset of the acute form is sometimes attended by some con- stitutional disturbance, especially when many nerves are affected. The chief symptoms are local. The most prominent is pain, felt in the inflamed part of the nerve, and also often in the part to which 'it is distributed (see p. 78). Sometimes the pain involves the whole limb, and in severe cases it may be most intense, burning, boring, rarely darting, in character ; it is usually worse at night and increased by movement, by postures that involve tension or pressure on the nerve, and by whatever causes passive congestion of the limb, such as the act of coughing. Sometimes it seems to radiate into distant parts, and not rarely pain is also felt in thb corresponding region of the opposite limb. The sensitiveness of the whole of the affected region is increased, and even the bone may be tender, so that at fii-st attention may not be directed to the nerve, but when this is pressed great pain 86 NEURITIS. is always produced. In slighter cases tlie pain is usually limited to tlie nerve and its distribution. It may, indeed, be absent when the nerve or branch is chiefly motor, a fact difficult to explain unless the sheaths of such nerves contain fewer sensory fibres than usual. If the nerve is accessible to direct examination it may be felt to be distinctly swollen at the affected part. Occasionally the sMn over it has been observed to be red, and rarely there has been slight oedema. Spontaneous sensations may be felt in the region supplied by the nerve, tingling, &c., and the sldn may be hypersesthetic. After a time, as the nerve-fibres suffer, sensation may be perverted, or even lessened ; complete anaesthesia is usually confined to small areas. The muscles supplied by the nerve become weak in various degree, tender, and present fibrillar twitchings ; they are seldom powerless, but pain may prevent their contraction. They present the altered electrical reac- tions characteristic of nerve-lesions. Increased perspiration has been observed in the part of the skin supplied by the inflamed nerve, very rarely it is arrested, and sometimes, although rarely, eruptions occur. Herpes is not common from ordinary acute neuritis. The epidermis may become thickened into a state like ichthyosis, or may atrophy and appear as " glossy skin." Effusion into joints has been observed in very rare cases. The constitutional disturbance which may attend the onset subsides ia the course of a few days, but the pain and other symptoms usually persist in undiminished severity for several weeks. They ultimately slowly subside into a chronic stage, and may continue as a secondary neuralgia due to a habit of over-action set up in the centre. In the chronic form constitutional disturbance is absent, and pain is the prominent symptom from the first. The affection of motion and sensibility, and the trophic changes, are similar to those met with in the acute form. In both forms the muscles may waste, and present the reaction of degeneration when they are tested with electricity (p. 73). In slight cases the initial increase of excitability in the nerve is often well marked. Trophic changes in the skin are very common ; so is alteration in the nutrition of the joints, and adhesions form, limiting the movement, and fixing the parts in the position corre- sponding to the muscular inaction. When neuritis ascends a nerve, the symptoms gradually extend in area ; and if it reaches the plexus from which the nerve proceeds, they may extend to most or all the nerves of the limb. This " ascending neuritis" is not rare in man, may even reach the spinal canal, and there produce various disturbances. The inflammation may spread in the tissue outside the dura mater, or may extend to the cord, and cause subacute or chronic myelitis with or without meningitis. The paralysis that occurs secondarily to some visceral diseases, as those of the bladder, and commonly regarded as reflex paralysis, is probably produced through the agency of an. ascending neuritis. Lastly, the inflammation maj -^xtend to the nerves of the DIAGNOSIS — PROGNOSIS. 87 other side, usually to those that correspond to the primary seat of the disease. Such extension may be through the spinal cord or the membranes, but in some cases symptoms occur in the nerve of the opposite side, without any indication of an affection of the centres. Experiments on animals have demonstrated that such implication of the opposite nerve may occur when the centres are unaffected. It has been called " sympathetic neuritis." We have seen that reflected pains are occasionally felt in the corresponding nerve on the opposite side, and it is probable that, as in neuralgia, vaso-motor disturbance in the nerve- sheath may accompany such pains, and, in a predisposed person, may cause actual neuritis. The Duration and Course of neuritis vary much. A slight acute neuritis may run its course in a few weeks and then subside. Much more commonly the affection persists in a chronic stage for many weeks, or even months, and slowly passes off. The rheumatic and gouty forms are as a rule much more tedious than those that result from injury, although traumatic neuritis is sometimes very insidious and may last a long time ; it may ascend the nerve from its starting- place and become localised in certain situations, where it may develop afresh, and give rise to symptoms that often seem to be independent of their cause. In the predisposed, it can set up troublesome local functional disturbance, hysterical contracture, and the like. DiAauosis. — The diagnosis of neuritis depends, first on the localisa- tion of the symptoms to the distribution of a certain nerve-trunk, and secondly on the pain and tenderness in the nerve. The diffuse pains that attend the onset may be readily mistaken for the pains of acute rheumatism, or for those due to an inflammation of the bone, but in the course of a day or two the localisation of the symptoms declares their nature. The chronic form is easily and often mistaken for neui'algia, and the diagnosis is the more difficult because many so-called neu- ralgias are really due to neuritis. The distinction can only be fully discussed when we have considered the symptoms of neuralgia, but it rests chiefly on the fact that in neuralgia the pain intermits more completely than in neuritis, there is not the same initial tenderness in the nerve-trunks, and the tender spots have a more uniform localisation. Lessened sensibility or change in the muscles, showing organic damage to the nerve-fibres, are conclusive evidence of neuritis. The pains in some central diseases, chiefly those of the spinal cord, may be thought to be due to neuritis, but there is not the local tenderness of the nerve- trunk, and the pain is not limited to the distribution of a single nerve. As we shall see presently, the diagnosis of multiple neuritis from affections of the cord is far more difficult. Peosnosis. — The gravest form of simple neuritis is that in which the nerve is affected secondarily to a local suppurative inflammation. The prognosis is best, as a rule, in traumatic neuritis, but the rule is one to which the exceptions are occasionally very considerable in degree. A neuropathic disposition makes the prognosis worse. In all cases 88 NEURITIS. the intensity of tlie symptoms, and tlie evidence of descending degene- ration, furnish a more trustworthy guide to prognosis than does the mere form of the affection. The effects of complete degeneration always endure for some months. Eegeneration does not occur until the original cause has ceased to act, and then occupies many weeks in its progress to the restoration of functional competence. In all forms pain is apt to linger on, and the longer the older the patient is. Treatment. — The first consideration in the treatment of neuritis is the removal of its cause, if this can be discovered. A wound or injury or local inflammation adjacent to the nerve must be dealt with by appropriate measures. Any constitutional cause, such as gout, must be treated. For the inflammation of the nerve, it is of the first importance to secure to the part as perfect rest as possible. Move- ment causes mechanical irritation of the nerve, and involves functional stimulation of its fibres, both of which are injurious. The nerves of a limb run between muscles, and the contraction of these muscles causes pressui-e on the inflamed nerve, and irritates it, as the pain thus produced sufficiently shows. Pain is indeed a useful indication of the harmful influence of movement, since the stimulation of the nerves of the sheath, in which the pain is produced, doubtless has also a reflex effect, increasing the vaso- motor element in the infl "animation. Hence it is most important that all movement that causes pain should be avoided. The posture of the limb should be such as to involve the least pain and the least danger of secondary contracture. The general treatment of an acute neuritis must be that suitable for any acute local inflammation, whatever its seat, — an unstimulating diet, an aperient, and diuretics. In gouty cases a brisk purgative may, with advantage, be given. General diaphoresis is useful in cases that are due to cold, and in others local sweating is often of distinct service. The limb may be steamed, or exposed to hot air. This should be followed by hot fomentations applied along the course of the affected nerve, and these by linseed-meal poultices. Leeches may also be employed at the onset of severe cases. When the inflammation results from injury, cold may be applied along the course of the nerve instead of heat; both probably modify the vascular disturbance of inflammation in a similar manner. Counter-irritation may be used at the onset of slight cases ; but when the inflammation is severe, this agent is more effective during the subsidence of the inflammation than during its active stage. Blisters, repeated mustard plasters, or stimulating liniments may be used, but care must be taken not to blister skin that is ansesthetic, or troublesome ulceration may be caused. The same caution is necessary in regard to hot applications, as is shown by the case mentioned on p. 79. Spontaneous pain requires sedatives, of which the hypodermic injec- tion of morphia is by far the most potent. It should be used only for spontaneous p; in, and not to enable the patient to use the limb in a way that would | reduce pain if morphia were not given. Mechanical TEEATMENT. 89 irritation may be equally injurious, although the pain which it wotild cause is obviated by the sedative. Moreover it should only be used as a last resort, when the agent to be mentioned next is inadequate. Morphia has little influence o^ the morbid process ; it lessens the effect of the disease on the brain only by acting on the brain. In cocaine we have an agent capable to a large extent of replacing morphia, and of a greater therapeutic capacity. Although it has less power of relieving pain, it is capable of doing much more than that. It arrests the local transmission of the impulses that cause pain, and so, at a limited region, it does lessen pain and often remove it for a time, and the local character of its action enables it to exert a simul- taneous influence on the morbid process. It prevents the irritative influence on the inflamed structures of the impressions that are felt as pain, which we have just considered; and the entire arrest of the influence, even though the region is small, seems to produce a much greater effect on the process than might be anticipated. It is in- structive to note the opposite influence, revealed by the occasional redness of the skia and subcutaneous oedema, along the course of the inflamed nerve. The injection should be made at one of the seats of pain. In the rheumatic form salicylate of soda has been given, but is of doubtful value. Iodide of potassium sometimes seems to be useful, but no agent has so distinct an influence on the process of inflam- mation in the nerve as small doses of mercury. A grain of blue pill may be given once or twice a day ; and if morphia has to be injected at the same time, the mercury is useful also in correcting the constipating influence of the morphia. In the chronic stage or form, counter-irritation, by blisters or cautery, is of great value. So also is electricity, which has little influence during the acute stage. The voltaic current should be used. The positive electrode may be placed over the inflamed part of the nerve, or over the seat of pain, and kept there for ten minutes at a time, the strength of current being slight, such as the patient can just perceive. In very chronic cases a stronger current, sufficient to cause actual pain, is of service, applied in a similar n:anner, but for a shorter time. It has probably chiefly a counter-irritant influence, and faradism may be used in the same way. All painful impressions on the skin lessen, for a time, the nerve-pain. The muscles supplied by the inflamed nerve may be left alone, unless their wasting is marked, or the degenerative reaction shows serious damage to the motor fibres. In cases of moderate severity they will recover when the nerve recovers. All that is desirable is that they should be gently rubbed once or twice a day. If the wasting is considerable, however, or there is degenerative reaction, they should be stimulated to gentle contra jcion by a weak, slowly interrupted voltaic current. They should on no account be faradised during the active stage of the affection, even if they act to faradism. The acute pain that the faradic stimulus causes, and the increased tender- 30 NEUKOMA. ness tliat lasts for hours afterwards, are evidence of its injurioua effect. In all cases attention to the general health is of great importance. Tonics are needed during the chronic stage. Change of air will some- times remove, in a few weeks, symptoms that have previously been stationary for months. The modifications of treatment that are rendered necessary by the position of the neuritis will be considered when we come to speak of the affections of the several nerves. The pathological varieties of neuritis only need special treatment in so far as they depend upon special causes, and this point, as already mentioned, must always be one of the first considerations. MORBID GROWTHS IN NERVES : NEUROMA. The term "neuroma" has been applied indiscriminately to all morbid growths situated on the peripheral nerves. The discoveiy, by Virchow, that many of these consist of a growth of nerve-fibres, while others consist of heterologous tissue such as constitutes morbid growths elsewhere, has led to the distinction of the former as " true neuromata " and the latter as " false neuromata," or " pseudo-neuro- mata," and even to the limitation of the term " neuroma" to a growth of nerve-tissue, whether in the central or peripheral nervous system, the heterologous growths being called by the names they bear in other situations, as " fibroma," " sarcoma," &c. The latter system of nomenclature, although certainly more consistent, has not become current in this country. The true neuromata may consist of meduUated or of non-medullated nerve-fibres, termed " myelinic " and " amyelinic " forms by Yirchow. The latter were for a long time regarded as fibrous. The occurrence of ganglion-cells has been proved in only one or two instances. There is connective tissue between the nerve-fibres, which varies in amount and in character, and hence the firmness of these tumours also varies. This interstitial tissue may be so abundant as to constitute an inter- mediate form between the true and false varieties. This is probably the condition in most cases of multiple neuromata. The " false neui-o- mata " may be of various nature, but fibrous growths, " fibromata," are far more common than any other kind. Myxoma occasionally occurs, the new mucoid tissue growing from the nerve-sheath. In one case * a myxo-fibroma as large as a goose egg involved the • Schuster, • Zeitschr. f. Heilknnde,' 1886, vii. NEUROMA. 91 slieatli, and pressed on the median nerve, a piece of which, -when resected with the tumour, showed hyaline degeneration of the medul- lary sheath, the axis-cylinders persisting in a slightly swollen condi- tion. Glioma is very rare on the peripheral nerves, although occa- sionally found on the auditory nerve ; it should be remembered that this form of growth arises from the same embryonal tissue as true neuroma. Various forms of sarcoma have been met with. Carci- noma also occurs, very rarely as an isolated growth, but not un- commonly as a more or less diffused or nodular infiltration of the nerve, arising by extension from a contiguous growth.* Syphilitic growths are common on the cranial nerves within the skull, but are rare elsewhere. In lepra ansesthetica the nerves are infiltrated with fibrous tissue, enlarging them to many times their normal size. The enlargement is rarely nodular, and is rather a chronic cirrhotic inflammation than a growth. (See Leprous Neuritis.) A curious variety of neuroma, consisting of interlacing cords, more or less nodular and tortuous, is termed plexiform neuroma. The disease commonly begins in foetal life, and is most common on some branch of the fifth nerve in the orbit or the upper eyelid, but has been met with over the temporal bone, in the lumbar, cervical, brachial, and solar plexuses, on the penis and the mamma. It may be quite superficial or deeply seated. The cords, from 1 mm. to seve- ral centimetres in diameter, consist of a clear outer zone of concentric fibrillar connective tissue, of inner looser nucle- ated tissue, and, in the middle, a bundle of nerve-fibres, some normal, others de- generating. The cords are connected together by loose tissue, sometimes myxomatous, separated from the proper tissue of the cords by an epitheliated space. The growth of this form is extremely slow, but it may exert compression on adjacent structui'es.f A remarkable case of extensive myxomatous disease of the nerves of the forearm, congenital in origin, pre- senting analogies to plexiform neuroma, is recorded by Mr. De Morgan. J * A unique case of rliiibdomyoma occurring jr- a nerve is recorded by Orlandi ('Arch. p. 1. sc. rned.,' xix, 5). t Maichand, ' Viichow's Archiv,' Bd. Ixxvi, p. 36. J ' Path. Trans.,' vol. xxvi, p. 2. Fia.45. — Plexiform nenioma from theorbit. (After Mar- chand.) The connective tissue surrounding tlie corda has been removed except at «,and irregular, cylindrital, nodular cords are seen anastomosing. A nerve pussea into the tumour and suddenly becomes enlarged. '%d^ 92 NEUROMA. The subcutaneous extremities of sensory nerves are sometimes enlarged into minute tumours which, when painful, have been termed " tubercula dolorosa." Neuromata in the skin may co-exist with similar tumours on the nerve-trunks. Those shown in Pig. 46 are from the same case as the tumoui's represented in .1 I Figs. 47—49. The size attained by growths on nerves varies from that of a child's head to a nodule only just visible. They rarely exceed the dimensions of Pia. 46. -Cutaneous neuromata from the closed fist. The variation in size skin of abdomen. (After Smith.) » i. • i j • -n , . -i . ' 01 multiple neuromata is illustrated in Figs. 47 — 49, after Smith.* The large tumour (Pig. 47) was the size of a lemon, but in the same case a growth from the sciatic plexus Fio, 47. Fig. 48. Fia. 49. Fi&. 50. \J u FiG. 47. — Right elbow of a man, set. 30, with multiple neuromata; those on the nerves of the arm are visible beneath the skin as moniliform series of swellings along the course of the nerves- (After Smith.) Fig. 48. — Part of the brachial plexus and nerves of the arm. Fig. 49. — Neuroma of the posterior tibial nerve, same case. The tumour was the size of a lemon, and could be felt in the popliteal space. The flattened bundles of fibres of the nerve were separated and passed over the surface of the tumour. The portion of nerve to the right is a piece ot the external popliteal. The tumours caused no interference with function. The patient died of enteric fever. One large tumour tilled the pelvis. Fig. 50. — Small neuroma of popliteal nerve laid open. It is seen to lie within the sheath. It caused no symptoms during life. (After Smith.) almost filled the pelvis. They may occur on any nerve in the body, cranial or spinal, and are sometimes numerous on the pneumogastrics, spinal roots, and sympathetic plexuses. When neuromata are multiple * R. W. Smith, ' Treatise on Neuroma,' 1849. Many instructive cases have been collected by Bowlby (• Diseases and Injuries of Nerves'). CAUSES. 93 they are often extremely numerous, and almost every nerve in the body may be transformed into a chain of growths. In the case figured more than 200 were counted in the right arm alone, and the total number of growths in the body cannot have been less than 1000, while in another 3020 were counted.* These multiple neuro-fibromata have a great tendency to undergo sarcomatous degeneration. They have hence been termed " secondarily malignant neuromata. "f The tumours are almost always within the sheath of the nerve (Pig. 50). Sometimes they are on one side, and the nerve may pass by unchanged. More often the substance of the nerve is involved, and the fibres may be separated and spread out on the surface (Fig. 49). Even then they may not be damaged. They suffer far more in heterologous growths than in true neuromata. Causes. — The causes of neuroma are generally obscure. Multiple neuromata are sometiines hereditary, and are probably due, in most cases, to a congenital tendency of tissue growth. Plexiform and multiple neuromata have been met with in the same family. They are said to be sometimes the result of general neurotic predisposition, and evidence of this is found in the occasional occurrence of neuro- mata in the subjects of cretinism or idiocy, of which some remarkable examples have been recorded. It is now generally held that multiple and plexiform neuromata, together with the affection kaown as ele- phantiasis neuromatodes, are results of the same congenital process. J Multiple neuromata are said to be almost confined to men. The isolated form is not uncommon in women. They may occur at any age. Yirchow believes that they are unusually common in the phthisical and scrofulous. Of traceable immediate causes the most frequent is traumatic injury. Pressure, punctured wounds, or division of the nerves may give rise to them, apparently by a perversion in the process by which cicatrisation takes place. A well-known instance is the formation of the so-called " amputation neuromata," or " bulbous nerves," round or oval growths, the size of a bean or larger, which form on the divided extremities of the nerves in the stump left after an amputation. The occurrence of new growths containing nerve-fibres may seem to be very remarkable. We must remember, however, how frequently they are connected with traumatic causes, i. e. take origin in cicatricial processes. In such processes the nerve-fibres present a remarkable power of growth. Ranvier has shown that from the end of each old fibre several new fibres grow, only one of which probably ultimately persists. Under apparently mechanical influences some of these fibres may twist about, and even turn and grow upwards. It is thus not • 'Med. Times and Gaz.,' 1883, i, p. 152. f Garre, ' Beitrage z. klin. Cliir.,' ix ; Sclieven, ibid., xvii. J See especially Finotti, ' Virch. Arch.,* cxliii. Some go so far as to include molluscam fibrosnm in the same category (Soldau, ' Inaug. Diss.,' Berlin, quoted in •Virch. Jahrb.,' xxx, i, p. 231). 94 NEUilOMA. diflBcult to understand ttat a true neuroma may result from injury tc a nerve ; it is said, indeed, that the ends of the nerves in amputation stumps are generally enlarged into minute bulbs, which contain more fibres than do the nerves on which they are situated.* Symptoms. — These may be entirely absent, especially in the case of multiple (true) neuromata, which are sometimes discovered post mortem when their existence has not been suspected. Often, how- ever, they cause marked symptoms. The most frequent is pain seated in the tumour (which may be extremely tender) or referred to the distribution of the nerve, often acute, burning, or darting, and frequently intermittent. It may be increased by pressure on the tumour. In the case of the terminal neuromata local pain may be the only sensory symptom ; but when the nerve-fibres suffer, parsesthesise, numbness, or formication may be complained of, and ultimately sen- sation may be lessened or lost. Paralysis of the muscles supplied by the nerve is occasionally met with, the region paralysed corresponding to the distribution of the nerve on which the tumour is situated, except in the case of neuromata in the cauda equina, from which paraplegia may result, with flexor spasm. A neuroma of the pneumo- gastric may cause grave cardiac disturbance, sometimes increased by pressTire on the tumour. More common motor symptoms are reflex spasms in adjacent or even distant muscles. For instance, in a case of " bulbous nerves " in the stump after amputation at the shoulder- joint, the muscles on that side of the neck were in constant clonic spasm. Occasionally epileptiform convulsions are produced, and have been known to cease when a painful neuroma had been excised. The occurrence of these symptoms has little relation to the size of the tumour. When the neuromata are in accessible situations they may be felt. Sometimes they give rise to visible tumours, and in multiple neuroma the course of the superficial nerves may be marked out by lines of bead-like swellings, as in Fig. 47. The cutaneous neuromata also cause visible swellings. The whole abdomen was covered with such nodules in the case recorded by Smith (Fig. 46). They are sometimes not sensitive, sometimes exquisitely tender and most painful, especially when closely united with the skin. Pressure on the nerve above the tumour commonly lessens the pain. Plexiform neuroma rarely causes other symptoms than the signs manifesting its local presence. The functions of the nerve-fibres involved are not usually interfered with. Once or twice anaesthesia of the skin has been observed. Course. — The growth of neuromata varies greatly in rapidity. When symptoms occur they most commonly last for a long time, increasing in severity, and f vom the long-continued pain the patient may ultimately be worn out. In other cases the symptoms show • Bowlby, loc. cit., p. 20. DIAGNOSIS — PROGNOSIS TEEATMKNT. 95 little tendency to increase, and in rare instances they may lessen in severity and even disappear. Diagnosis. — The recognition of the existence of a neuroma depends on its superficial position, or on the production of symptoms of damage to the nerve. The latter, when existing alone, are equivocal, since they may be due to pressure on the nerve from an adjacent growth, or even to neuritis. The disease may be suspected if symptoms — pain, numb- ness, weakness — occur, limited to the distribution of a nerve-trunk, and no cause of external pressure can be discovered, and the long course of the symptoms makes it unlikely that they are due to neui'itis. The diagnosis can, however, only be certainly made when the tumour can be felt. Secondary subcutaneous sarcomata may very closely resemble neuromata. The diagnosis of the kind of neuroma, whether " true " or " false," i. e. composed of nerve-fibres or other tissue, is very difiicult. Multiple neuromata are usually true, and of very slow growth ; false neuromata are rarely multiple unless they are of infecting nature and rapid in development. The existence of idiocy, or other neuropathic indication, is in favour of the neural nature of the tumours. The lateral position of the growth on the nerve is in favour of its "false " character. The diagnosis of plexif orm neuroma is only possible when the tortuous nodular cords can be felt. Peognosis. — This depends on the existence of symptoms. If these are absent, unless the tumour is of rapid growth, there is good reason to hope that they will not occur. In multiple (true) neuromata the nerve is less likely to suffer than in isolated growths. If symptoms are present the jDrognosis is less favorable, and depends on the ten- dency which they exhibit to increase. Treatment. — Medicines are useless except in the syphilitic forms of nerve-tumour, not here considered. Extirpation is the only remedy. If the tumour is lateral, and can be shelled out, the removal entails little risk. If, however, the growth infiltrates the substance of the nerve, the affected part must be excised, and the ends brought together. The risk of permanent loss of function in the nerve is great, and in deciding on such an operation, the urgency of the symptoms, and the importance of the function of the nerve, must be taken into consideration. After the extirpation of such tumours, the tendency of cicatricial processes in nerves to go on to the formation of similar growths (seen in " bulbous nerves ") renders the chance of relapse considerable. The operation reproduces conditions favorable for the activity of whatever predisposing influence aided in the original development of the disease. When neuromata are multiple, surgical treatment is out of the question, excep"'. for isolated tumours that cause distress. In the case of terminal neuromata — whether the cutaneous " tuber- cula dolorosa " or the amputation neuromata — excision is practicable, and it us unattended with the risks attending interference with a 96 ^ SPINAL NERVES. nerve in its continuity. In amputation flaps the chance of a relapse is considerable. In plexif orm neuroma excision is undesirable, and no other treatment is of any use. Pain, and the reflex spasm, that are so distressing in amputation neuromata, need relief when attempts to cure have failed. By nerve- stretching we may perhaps give relief without the effects that follow excision, and in cocaine we have a means of arresting for a time the ingoing impulses that play an important part in generating the symptoms. The rest thus given to the centre is absolute, and its degree and frec^uent repetition may compensate for its brevity. DISEASES OF SPECIAL NERVES. The diseases of the cranial nerves may be most conveniently considered in connection with the diseases of the braia. Her«, therefore, only the affections of the spinal nerves will be described, in so far as they present special features. The effect of paralyais of the individual muscles has been already described in detail, and need not be here repeated, except in general terms, or in so far as the association of palsies resulting from a nerve-lesion presents a parti- CTolar character. Phebnio Nerve. — Impaired function of the phrenic nerve is commonly the result of disease of the spinal cord, or of the roots of the nerve — the third and fourth cervical trunks — from disease of the membranes or the bones. The deep position of the nerve-trunk pro- tects it from injury, but it is occasionally damaged in wounds of the neck, and in its course through the thorax it may be compressed by tumours, aneurisms, &c., or involved in inflammations of the pleura. Paralysis of one nerve . sometimes follows exposure to cold, and is ascribed to neuritis. That of both has been met with in multiple neuritis ; it has also been observed following diphtheria and influenza, in the course of tabes (Grerhardt) and progressive muscular atrophy, and in poisoning by lead and alcohol. In disease of the spinal cord and membranes both nerves are usually paralysed ; causes acting on the nerve-trunk usually affect one only. The effect and symptom of paralysis is inaction of the diaphragm (see p. 33). If one nerve only is affected, the diaphragm does not descend on that side, but the movement of the other side lessens the resulting defect of movement, and it can then be detected only by close observation. The loss of the action of the diaphragm has little effect on the respiratory functions while the patient is at rest, but dyspnoea is said to be readily pro- duced by exertion ; the breathing then becomes quick and the voice NERVES OP THE ARM. 97 feeble. At the same time this is probably chiefly because too much and too constant work is thrown on the upper thoracic muscles of extraordinary breathing. Any lung disease, such as an attack of bronchitis, is rendered far more serious by the diminished breathing power. When the diaphragm is paralysed, the movement of the thorax is often increased, and the expansion of the lower part may draw forwards the adjacent abdominal wall. This must not be mis- taken for the effect of the descent of the diaphragm. Paralysis has to be distinguished from (1) abnormal ner\ o is breathing. The dia- phragm is used little in extraordinary breathing, which is chiefly by the upper part of the thorax, of the " superior costal type," as it is called. Hysterical and nervous patients will often breathe, for a time, only in this manner, even when at perfect rest, especially when they are under observation. Such breathing is no doubt faciUtated in women by the fact that the diaphragm is habitually used by them less than by men. Repeated examination may be necessary to deter- mine whether there is any real paralysis of the diaphragm in these cases. A single diaphragmatic inspiration settles the point. The patient's attention should be distracted, and she should not be aware of the object of the examination. (2) Inflammation of the diaphragm may arrest its movement, and so also may diaphragmatic pleurisy or peritonitis — each distinguished by the fact that it is usually secondary to adjacent inflammation, and any movement causes characteristic pain. (3) A primary and isolated degeneration of the muscular fibres of the diajohragm has been described by Callender and others as com- mon after death, but it has not yet been proved to cause symptoms, and needs further investigation. Paralysis may be due to disease of the nerve, its roots, or of the spinal cord. In the latter case other muscles always suffer ; in the former the diaphragm usually suffers alone, the result of peri- pheral neuritis. The distribution and the course of the other palsies are distinctive. By far the most common cause is disease of the spinal cord, local or ascending from below and adding this final effect to the preceding palsy of the intercostals. In disease of the nerve-roots there are other indications of the position of the disease. The affection is often overlooked because not searched for, especially in local disease of the cervical cord. The observer forgets that its associations are not with the lower dorsal muscles, and he omits to look for it in cases in which the cervical cord is suffering and other respiratory muscles act weU. If there is reason to suspect partial neuritis as from cold, hot fomentations at first, and afterwards cotmter-irritation, should be applied over the lower and inner part of the anterior triangle of the neck. The only other special point in treatment is the appHcation of electricity. The nerve may be stimulated by pressing the rheophore deeply outside the lower part of the clavicular portion of the sterno- mastoid. The other pole may be placed at the epigastrium or over the VOL. I. 7 9o SPINAL NERVES. corresponding lialf of the diaphragm. But the influence of electricity on paralysis of the diaphragm is not sufficient to make its use desir- able. In the cases in which such treatment could do good the affec- tion is transient and comparatively unimportant. In central disease electricity has very little influence. Neetes of the ITppeb Limb. The nerves of the arm and shoulder are derived from the five lovrer cervical and the first dorsal nerves. These interlace in the brachial plexus in such a complex manner that most of the nerves of the arm are derived from many spinal roots. The nerve-roots form, by their union, three trunks, which we raay indicate by Roman numerals. They are formed thus : — I, by the branch from the fourth, and the roots of the fifth and sixth cervical ; II, by the seventh ; and III, by the eighth cervical and the first dorsal. Each trunk divides into two parts, and the union of these divisions forms the three cords of the brachial plexus from which the nerves of the arm proceed. But before the primary trunks divide, certain nerves arise, the origin of which is thus less doubtful. The fifth and sixth cervical roots give origin directly to the posterior thoracic nerve for the serratus, and from the cord formed by their union springs the supra-scapular nerve. The three cords of the plexus have the following relations: — The posterior is derived from all three primary trunks, and gives rise to the subscapular nerve, the cireninflex, and the musculo-spiral (or radial, as the whole nerve is sometimes termed). The upper or outer cord is derived from the two upper primary trunks, i. e. from the fourth, fifth, sixth, and seventh cervical roots, and from it proceed one anterior thoracic and the musculo-cutaneous nerves, together with the outer head of the median. The inner or lower cord is derived only from the lowest primary trunk, '. . from the last cervical and first dorsal, and gives rise to the ulnar, the inner head of the median, the internal cutaneous, the intercosto-humeral, and to the second anterior thoracic nerves. It may be convenient to put these coarse anatomical relations in the form of a table. Nerves. Primary Trunks, Nerves, Subscapular ••« _ Circumflex .1 ' Musculo-spiral J Upper cord Lower cord fExtemal ant. thoracic. J Musculo-cutaneous. [Outer head of 'j j- median. /•Inner head of J Ulnar. Internal cutaneous. Intei-costo-humeral. ^Internal ant. thoracic. These anatomical facts, however, give us little help in tracing the relation of the nerves to the spinal roots. The investigations of Ferrier and Yeo,* who * 'Pioc. Roy. Soc.,' March 2L>t, 1881. Careful dissections by Herringliara (cf. March 25th, 1887) give somewhat different results, but this method of investigation is open to more uncertainties than that of stimulation. Herringham's conclusiona .should, however, be noted by future investigators. NEEVES OP THE AEM. 99 ascertained tlie movements produced by faradisingthe several spinal roots in the monkey, show us the way in which the movements, muscles, and nerves are represented in the spinal roots. Their results are therefore of great interest, although we are not justified in transferring the facts to man except in bo far as they receive confirmation from human anatomy and pathology.* Subject to this reservation, the chief results are important, and may be thus stated rf The roots to which the several nerves are thus traced are as follows : — Sub- Bcapular, 6 and 7 C. ; circumflex, 4 and 5 C. ; musculo-spiral, 4, 5, 6, 7, 8 C. ; musculo-cutaneous, 4, 5 C. ; median, 5, 6, 7, 8 C. ; ulnar, 8 C, 1 D. Still more important are their observations on the relation of various move- ments of the arm to the nerve-roots, and these are as follows: Cervical 4i.— Elevation and retraction of the arm, flexion and supination of the forearm; by the rhomboids, supra- and infra-spinatus, biceps, brachialis, and supinators. Cervical 6.— Similar to the last, but without retraction of the arm, and with extension of the wrist and first phalanges ; by the deltoid, serratus, flexors of elbow, extensors of wrist, and long extensors of fingers. Cervical 6. — Adduction and retraction of the upper ai-m, extension and pro- nation of the forearm, flexion of the wrist ; by contraction of the pectoralis, latissimus dorsi, triceps, flexors of wrist, pronators. Cervical 7. — Adduction and rotation inwards at the shoulder-joint, flexion of the wrist, and of the fingers at the second phalanx; by the teres major, latissimus dorsi, subscapularis, triceps, and long flexors of the fingers. Cervical 8. — Flexion of fingers and thumb so as to close the fist ; flexion of wrist towards the ulnar side, pronation of forearm, extension of elbow ; by the intrinsic muscles of the hand, the long flexors of the fingers and thumb, the flexors of the wi-ist and the triceps. Dorsal 1. — Adduction of the thumb, flexion of the fingers at the metacarpo- phalangeal joints ; by the interossei, &c. Thus most movements are related to many spinal roots. The nerves supplying each muscle have a correspondingly multiple relation to the spinal roots. It cannot be traced anatomically, but has been ascertained by comparing the results of experiments on animals with those of disease and injury in man, and (in the case of sensation) of the division of roots for the treatment of some forms of disease. The facts thus ascertained have been confirmed by cases of disease of the spinal cord itself, which, when sufficiently limited to be significant, have been found to agree closely with observations on the roots. The con- stituents of each nerve-root come from a definite part of the cord, which is termed the corresponding spinal "segment." A single muscle is seldom related to a single segment ; usually its nerve-fibres come from pai-ts of two segments, or even from three. Its representation in the grey matter of the cord corresponds to its relation to the nerve-roots, and has often a considerable vertical extent. The most important relations are these : that of the deltoid, rhomboids, supra- and infra-spinatus, flexors of the elbow, and supinators to * In the case of the leg there are some important discrepancies between the results in the ape and the conditions that obtain in man. These will be noticed in their proper place. t Ferrier has since stated that the relations he gave (followed in the text) were all one nerve too high (' Proc. Roy. Soc.,' 1883, vol. xxxv, p. 229), but this would make the itmervation of the intrinsic muscles of the hand from the second dorsal uerve^ which is certainly not the case in man. 100 SPINAL NERVES, the fourth and fifth cervical ; that of the adductors of the arm and extensort of the elbow to the sixth and seventh nerves; pronation to the sixth and eighth ; extension of the wrist to the fifth ; flexion to the eighth ; extension of the first phalanx to the fifth; flexion of the fingers to the seventh and eighth, and the action of the intrinsic muscles of the hand to the first dorsal. These facts will probahlj, in the future, find important practical applications. Eegarding the relation of the sensory branches to the nerve-roots, we have, hesides the facts of anatomy, only the evidence furnished by rare cases of injury or disease in which the lesion and its effects are well defined.* Few facts of this character are, however, so conclusive as that illustrated in Fig. 51, in which the area shaded by slanting lines was rendered anaesthetic by the division of the posterior roots of the last cervical and first dorsal nerves. The general indications are that the distribution of the sensory fibres of the nerve-roots is along the axis of the limb, and not across it. The last two pairs of nerves supply the ulnar side of the limb and the finger tips, the fifth pair the radial side and the middle roots of the brachial plexus, the middle zone of each side of the limb and the thumb.f ilUlUi^ ^'^ ' ^jijjjJ^^'mim^^ Fig. 51. — Area of impaired sensation after division of the posterior branches of tlie 8th C. and 1 D. nerves, by Professor Horsley for inveterate paroxysmal neuralgia in that region. Paralysis of tlie nerves of the upper limb may be due to disease of tbe nerve-roots, of the plexus, or of the trunks that arise from these. It is convenient to consider first the diseases of the nerve-trunks, and afterwards those of the nerve-roots and of the plexus. From the roots themselves only one important nerve-trunk is derived : — the pos- terior thoracic nerve. The others spring from the plexus. '±he morbid influences that affect the nerves of the arm are veiy varied. The brachial plexus passes close to the shoulder- joint, and hence dislocation often damages the nerves, sometimes one only, some- times several, and occasionally all the trunks. In fractures of the * Instructive facts of this character will be found in papers by Thorburn, * Brain,' January, 1887, and October, 1887, Allen Starr ('American Journal of the Medii-al Sciences/ 1892), and Head (' Brain,' 1893 and 1894), who has mapped out tlie areas representing the segmental distribution of the sensory fibres of the spinal ci'rd by means of obsei-vations on superficial tenderness accompanying visceral disease, on cases of herpes zoster, and on cases of spinal cord disease. (See diagrams at end of Chapter on " Functions.") t This is due to the mode of growth of the arm-bud in the embiyo, as shown by Ross in a most instructive paper, ' Brain,' January 7th, 1888. See also chapter on ilie Functions of the Spinal Cord. NERVES OF THE ARM. 101 bones the nerves adjacent may be torn, or may be compressed by the ends of the bone, or by the callus that is formed, especially by the exterior " fibrous callus.'* The musculo-spiral nerve is most prone to suffer from its proximity to the humerus, and in one such case the nerve, when exposed,- was found not only to be embedded in the callus tissue, hut to have been divided for about one-third of its diameter, opposite the fracture. Bandages that are applied are occasional sources of compression, and there is especial danger of harm from those that secure a splint applied to prevent motion in cases of neuritis. Unless loss of sensation draws attention to it, the injury is generally only dis- covered when the splint is given up, and therefore its possibility should be remembered. The course of certain nerves is, in some parts of the arm, especially apt to be directly involved in wounds of various kinds, or they may be compressed by the cicatricial fibrous tissue when the wound is merely near the nerve. The position of some exposes them to pressure against the unyielding bone. .Even slight pressure on these nerves is effective when prolonged, as it often is during sleep, when warning sensations are unperceived. The sleep induced by alcohol is especially apt to be attended by this accident. Hence there is a group of " 8leep-palsies " of the arm, chiefly of the muscido- spiral and median nerves, rarely of the plexus itself. One nerve, the musculo-spiral, passing between the bone and the triceps, is occasionally bruised by the contraction of the muscle. Primary neuritis may involve any nerve, or the brachial plexus, or the nerve-roots ; certain nerves are also particularly prone to suffer in peripheral neuritis. The inflammation of the plexus, which is a unilateral perineuritis, is separately described (Brachial Neuritis) ; the latter is considered in the general account of Multiple Neuritis. Secondary neuritis, set up by injury or by adjacent inflammation, may extend upwards, and, reaching the plexus, spread to other nerves. Neuromata are rare. Yarious morbid processes in the neck may involve the nerve-roots. Posterior Thoracic Nerve — Nerve, to the Serratus. — In consequence of its position and long course, the nerve to the serratus often suffers. After being formed in the substance of the scalenus medius muscle, by the union of branches of the fifth and sixth cervical nerves, it passes behind the brachial plexus and along the side of the chest to the lower border of its muscle. It is in the neck that the nerve is most often injured ; injury to the axilla less often implicates it. It may be damaged in the neck by direct pressure — as in carrying on the shoulder a heavy sharp-cornered object— or by severe muscular efforts, such as carrying a weight that does not press into the neck, wielding a heavy hammer, or long- continued exertion with the raised arm, as, for instance, in whitewashing a ceiling. In such cases a traumatic neuritis is set up by the violent compression of the nerve consequent on the forcible or prolonged contraction of the muscle through which it passes. Whe» 102 SPINAL NERVES. the onset of the palsy occurs immediately on the exertion, a paralysing injury to the nerve must have occurred, vyhich will be followed by secondary neuritis. Falls and blows on the neck and shoulder are occasional causes ; there is usually much bruising of the adjacent parts. Punctured and gun-shot wounds occasionally involve the nerve, which may also be affected in or after typhoid fever, influenza, and diphtheria. The least frequent cause is exposure to cold, such as a draught on the neck, or sleeping on damp earth. I have once known it to follow par- turition, developing four days afterwards, doubtless from neuritis excited either by the muscular exertion or by exposure of the neck to cold during the labour. An hysterical paralysis in the distribution of the nerve has been described by Yerhoogen. The serratus suffers also in central disease, chiefly in progressive muscular atrophy and dys- trophy and infantile paralysis ; but in these it is always associated with palsy of other muscles. Isolated paralysis of these nerves is nine times as frequent in men as in women. It occurs chiefly in muscular workers, and duriag the active period of life, twenty-five to forty. The immediate causes sufficiently explain this relation to age and sex, and they also account for another fact — that it is far more frequent on the right side than on the left. It is sometimes bilateral, but the two nerves are never damaged at the same time. One man was affected on the right side after carrying heavy beams on the shoulder ; he then carried them on the left shoulder, and the left serratus became paralysed. Severe neuralgic pains in the neck and about the shoulder commonly precede and accompany the onset of the affection when due to neuritis. The symptoms of the paralysis of the serratus have been already de- scribed (p. 35) . It is readily recognised by the recession of the posterior edge of the scapula from the thorax when the arm is put forwards (Fig. 8, p. 36). In severe cases the muscle is found to have lost f aradic irritability, although it may still contract to the voltaic current. The course of a severe case is always tedious. Months may pass before improvement is manifested, and the paralysis is sometimes per- manent. In treatment it is desirable to maintain the nutrition of the muscle, as far as possible, by electrical stimulation, and its superficial situation renders this easy. If counter-irritation is desirable, it should be applied over the position of the scalenus, since the lesion of the nerve is commonly at this place. The use of the arm should be limited. When practicable, the elbow should be carried in a sHng of eiich a length as slightly to raise the shoulder. AH movements that may involve contraction of the scalenus, i. e. all movements needing elevation of the shoulder, must be prohibited. The supra- scapular nerve arises from the trunk formed by the union of the sixth, fifth, and a branch of the fourth cervical nerves, but its fibres come from the fifth and partly from the fourth. It ia occasionally damaged, alone or with the circumflex, in dislocation of the humerus, and by falls on the shoulder, and by carrying heaw weights. In some cases the injury may be to the upper part NEBVKS OF THE ARM. 103 of the plexus (see p. Ill), which may recover except this nerve It suffered with the circumflex, in a case recorded by Eemak, from acute limited inflammation of the plexus, due to exposure to cold after over- use of the arms. Bernhardt has seen it following a faU upon the hand. The result of its disease is palsy of the supra- and infra- spinatus (p, 37). The latter is the more important, and causes a defect of the rotation outwards of the humerus, interfering with many movements, and, among others, with the movement of the pen along the line in writing. Undue work is thrown on the posterior part of the deltoid and the teres minor; the deltoid may become hypertrophied, and its posterior edge is conspicuous against the wasted infra- spinatus. The scapula is rotated, so that the lower angle is moved upwards and inwards. The paralysis of the supra- spinatus is unimportant, except that the humerus is less firmly fixed and the deltoid more readily fatigued. It can, in very slight degree, supplement the deltoid, and if paralysed with the deltoid, the head of the humerus falls more than it does when the deltoid is paralysed alone. Some anaesthesia over the scapula often results from disease of this nerve ; early in the affec- tion there is frequently severe pain in the region of the shoulder-girdle. The Circumflex nerve, although arising from the posterior cord of the plexus, seems to derive its fibres from the same source as the supra- scapular, the fourth and fifth cervical nerves. It supplies the deltoid and teres minor, and the skin over the deltoid. The course of the nerve renders it very liable to injury from dislocations and falls on the shoulder, and from the pressure of a crutch. Simple neuritis and so-called " rheumatic palsy " are rare, but the nerve has been affected in some acute diseases, possibly from pressure, and in rheumatic fever, perhaps by inflammation extending from the joint; typhoid and diabetes may also give rise to circumflex paralysis. It suffers, with other nerves, from disease of the upper part of the brachial plexus, and the chief symptom is paralysis of the deltoid (p. 36), which abolishes almost all power of raising the arm, a very trifling degree of abduction by the supra- spinatus alone remaining. The slight nerve- supply that the fore-part of the deltoid receives from one of the anterior thoracic nerves is insufficient to mitigate the effect of the paralysis of the circumflex, although it may maintain slight power of voluntary contraction in the anterior fibres, and this sometimes gives rise to an erroneous impression that the paralysis of the circum- flex nerve is incomplete. The effect of the conjoiaed palsy of the teres minor is unimportant. The wasting of the deltoid causes a change in the shape of the shoulder (Figs. 7 and 9). Sensation may be lost in the skin over the lower part of the muscle, and the loss sometimes extends on to the shoulder (Fig. 52) ; Hitzig pointed out many years ago that the anaesthetic area is often the seat of vaso- motor paralysis. In some cases there is no anaesthesia, even when the muscle is wholly paralysed ; we have seen that this is often the case in nerve lesions (p. 78). Adhesions are apt to form in the shoulder- joint, in 104 SPINAL NERVES. part probably the result of tropMc cbanges, since the circumflex suppHes tbe articulation as well as tbe cliief muscle that moves it. r,, ,,, ,y The diagnosis of the paralysis of the circum- flex nerve is easy. The only condition readily \ mistaken for it is anchylosis of the shoulder- / ' joint in a stout individual, in whom the state of nutrition of the muscle is not readily per- ceived. The risk of error is increased by the fact that arthritis and paralysis may result > from the same cause — a fall on the shoulder. \ Passive movement at once solves the problem. The scapula moves with the arm in anchylosis, and not in palsy. Furthermore, attempts at voluntary contraction leave the muscle flaccid, while if the affection is in the joint the muscle- |i:ii-I w^ •' ^~_..ui| fibres beome rigid in the attempt to contract. Vi&. 52.— Disease of the The importance of examining the joint is very circumflex nerve from great in all cases of interference with move- pressure neuritis during ^^^^ ^^ ^j^ shoulder. A' patient had an acute illness ; wasting ot ^ deltoid. Thedotte.iline epileptic fit which was supposed to have left mdic:)tcs the area of cu- "brachial monoplegia, merely because he fell on taneous ansesthesia. ,^ iin in- j p ,^ the shoulder, and the movement of the arm was lessened first by pain, and then by arthritic adhesions. In dia- gnosing the lesion from those of other nerves, the electrical reactions and the area of anaesthesia may be important. The Musculo-cutaneous nerve, supplies the chief flexors of the elbow and the skin over the radial side of the forearm. It is scarcely ever paralysed alone, but often suffers, with other nerves, in disease of the brachial plexus. In the few recorded cases the cause has been traumatic,* but in Eemak's case of jiaralysis of the supra- scapular and circumflex nerves on the right side, from limited neuritis of the plexus, there was complete palsy of this nerve on the left, thought to be due to a still more limited inflammation in the left brachial plexus.f The symptoms correspond to its function ; there is paralysis of the biceps and brachialis anticus (see pp. 38, 39), the effect of which is especially conspicuous when the arm is supinated and the suj)inator longus cannot flex the elbow. There may also be anaesthesia of the radial side of the forearm. The Musculo-spiral nerve is more frequently paralysed alone than any other nerve of the arm. Arising from the jDosterior cord of the brachial plexus, it seems to derive its motor fibres from all the nerve-roots that enter the plexus except the first dorsal. It suppHes the triceps, all the muscles on the back of the forearm, the extensors of the wrist and fingers, both the supinators, also the skin on the radial side of the back of the hand, the back of the thumb, index * See Bernhardt. ' Erkrank. peripher. Nerven.,' 1897, p. 329. t ' Neur. Ceutralbl.,' 1896, p. 578. NERVES OF THE ARM. 105 finger, and lialf the middle finger. It is thus the extensor nerve of the arm, and has a more complete relation to a single function than is common among the nerves of the limbs ; a fact that has given rise to diagnostic error, since a palsy limited to a single function suggests a central cause. The frequency with which this nerve suffers is due to its course. As it leaves the brachial plexus to wind round the bone, its positio^i. exposes it to injury in dislocation or from the pressure of a crutch ; the most common form of " crutch palsy " is paralysis of this nen 3. Lying as it does close to the humerus, it is readily torn in fracture, or compressed by callus, and it suffers gravely from even temporary pressure against the hard bone. Such pressure is often exerted during sleep, especially that induced by alcohol. The nerve may be paralysed by the pressure to which it is exposed when the body, with the arm beneath it, rests on the ground or on a hard bed. Thus a man slept all night on a bench, lying on his right side with his arm beneath him, and woke in the morning with this nerve paralysed. Curiously, a precisely similar event had occurred to him three years before. In other cases the pressure on the nerve is that of a hard and sharp object over which the arm is placed diu-ing sleep, as the edge of a chair or the side of a couch. The Continental custom of tying together, behind the body, the arms of a prisoner, often causes paralysis of this nerve, sometimes on both sides. In Russia it is not uncommon in infants, from the popular practice of binding the arms to the body and then laying the child to sleep on its side. I have three tiines met with paralysis from a violent contraction of the triceps, once during the act of pulling on a tight pair of boots, once from throwing a stone with energy, and once from grasping a lamp-post to avoid a fall during a severe attack of giddi- ness. In each the nerve was at once completely paralysed ; and in the second, in which the palsy was severe, a bruised appearance was ob- served over the lower part of the triceps. Neuritis due to cold is often assumed to be a cause, and is possibly sometimes effective, but the exposure has usually been during alcoholic sleep, and it is probable that the paralysis is due to compression rather than to cold. The same inflaence may also have been operative in cases in which the nerve has been paralysed during an acute disease. Although in a case of para- lysis during typhus, described by Bernhardt, neuritis was found after death, this was at the spot at which pressure is usually effective, and the inflammation was probably thus excited. Pressure always sets up neuritis, and the diagnosis of a primary neuritis is never justified if the spot affected is one liable to compression. Paralysis of this nerve, with others, has followed the use of an Esmarch's bandage ; and a partial palsy sometimes results from the habitual or even occasional injection of ether beneath the skin of the posterior part of the arm. The symptoms of disease of the musculo- spiral nerve are paralysis of the extensors of the elbow and of the wrist, the long extensors of the fingers and thumb, and the supinators (see pp. 37 — 40). All these are 106 SPINAL NER7ES. paralysed by a complete lesion of the nerve near the brachial plexus. When the lesion is near the middle of the humerus, as it is in most cases of compression, the triceps generally escapes, but not always. The supinator longus is usually paralysed, but escapes if the lesion is below the origin of its branch, and may also escape if the injury to the nerve is incomplete. In sleep palsy it usuully suffers, but I have seen it unaffected, in a case in which the ext. carpi radialis was also but little affected, and Bernhardt has noted the escape of the supinator in an otherwise complete paralysis from dislocation of the humerus. The extensor palsy causes characteristic wrist-drop, and loss of the power of extending the first phalanges of the fingers and the thumb (seep. 40). There is sometimes a gradation of palsy from the first finger, in which it is least, to the fourth, in Avhich it is greatest (Fig. 53). The same gradation is seen in lead palsy, and other forms of Fig. 53. — Pnralysis of the musculo-spiral nerve; maximum extension of wrist and fingers. The extension of the fingers progressively diminishes from the first to the fourth. (From a photograph.) peripheral neuritis. It is not easy to explain. The action of the flexors is feeble, from the loss of antergic support ; in most cases of complete palsy I have found the power of flexion reduced from this cause to one third of the normal. The loss of the power of supination is a grave inconvenience. If an object is grasped firmly the arm becomes pronated. The patient tries to compensate for the loss by putting the elbow against the side and rotating the humerus. Fig. 54.— Prominence at back of hand from para- The pronators may ulti- lysisof the extensors. Tlie patient was suffering ^g^^gj become shortened. from wrist-drop due to silver poisoning (see vol. ^ni n • e .t ii, " Aro-yria "). The over-tiexion or the carpus, and its deficient support by the extensor tendons, lead to a prominence of synovial sacs, and perhaps of the bones, at the back of the carpus (Fig. 54). In severe cases the muscles waste, and the maximum circumference of NEliVES OP THE ARM. 107 the limb below tlie elbow may be a quarter or balf an incli less than on the other side ; at the same time there may be thickening of the tendon-sheaths at the back of the hand. The electrical reaction depends on the severity of the lesion of the nerve ; commonly there is well-marked degenerative reaction. The affection of sensibility in the area supplied by the nerve is very variable. The skin of the upper arm rarely loses feeling ; in the hand sensation may be normal although the muscular paralysis is complete. There may be sub- jective "tingling" in the part although there is no loss of sensibility. The elbow- and wrist-jerks may be lost even when the reaction of degeneration is not present. The diagnosis is easy in most cases. The affection is distinguished from lead palsy by its common limitation to one arm, by the affec- tion of the supinator, and often by the sudden onset ; that from lead is gradual. The latter is further characterised by the early onset of the degenerative reaction in the affected muscles. These characters, and the commonly obtrusive cause, always suffice for the diagnosis. It must be remembered, however, that this nerve is one most fre- quently affected in many other forms of multiple neuritis (q. v.). The prognosis in disease of the musculo-spiral nerve depends on the severity of the lesion, as indicated by the electrical rea,ction. When there is evidence of nerve degeneration the paralysis usually lasts for some months. Eecovery ultimately occurs in almost all cases. The treatment is that for neuritis, already described, but attention should be paid to the posture of the limb, so as to avoid tension on the affected part of the nerve. For this reason, and also because strong contraction of the triceps may further injure the nerve, extension of the elbow should be avoided in cases of lesion of the nerve as it winds round the humerus. The Median nerve supplies the pronators, the radial flexor of the wrist, the palmaris longus, the flexors of the fingers (except the ulnar half of the deep flexor), the muscles that abduct and flex the thumb, and the two radial lumbricales. Its motor fibres seem to have an exten- sive origin from all the cervical roots that enter the brachial plexus. It subserves sensation on the radial side of the palm, on the front of the thumb, of the first two fingers, and of half the third finger, and also, at least in many persons, on the back of the last phalanx of the index and middle finger; sometimes also on the adjacent part of the back of the ring finger and the back of the last phalanx of the thumb. Isolated palsy of this nerve is not frequent, and generally results from wounds of the forearm, or fractiu^es of the forearm bones, rarely from injuries in the upper arm. The nerve is occasionally the seat of neuritis, which may be induced by compression, especially in those who, in their work, have to hold an object between the hand and upper arm. Occupation paralyses of this nerve have been observed in ironers, locksmiths, joiners, cigarette makers, and once in a dentist. The nerve may also suffer as the result of pressure of the head of the 108 SPINAL NEEVES. humerus in sleep or narcosis, while in former days it was not infre- quently injured by unskilful venesectors. I have known it to be paralysed at the wrist a few hours after a severe sprain of this joint. Webber has recorded a case in which it seemed to be injured by a violent contraction of the pronator teres. When there is com- plete damage to the nerve, pronation is impossible beyond the mid- position, to which the supinator longus can bring the forearm, and an attempt is made to supplement this by rotating the humerus inwards, and separating the elbow from the side. The wrist can only be flexed with a strong inclination towards the ulnar side. The thumb is in persistent extension and adduction (like the thumb of the ape, Figs. 22 and 23, p. 44), and cannot be opposed to the tips of the fingers. The power of flexing the second phalanges on the first is lost, and also that of flexing the distal phalanx of the first and second fingers, but this phalanx can still be flexed in the third and fourth fingers by the ulnar half of the flexor profundus (see p. 41). Inter- osseal flexion of the first phalanx is still possible, and the unopposed extensor action of the interossei on the middle and distal phalanges tends to cause a subluxation of the articulations concerned. The wasting of the thenar muscles is usually conspicuous. The resulting condition is very characteristic ; but if the damage is at the wrist, flexion of the wrist and distal phalanges remains. The sensory loss is variable ; it may be absolute or absent. If there is anaesthesia it is greater on the palmar surface, and will often be found also on the dorsal aspect of the extremities of the first two fingers. Trophic changes of the skin and nails are not uncommon. The Ulnar nerve comes, through the inner cord of the plexus, from the last cervical and first dorsal roots, and its origin from the lowest part of the cervical enlargement gives it an important relation, since it is the first of all the brachial nerves to be affected by disease that ascends from the dorsal to the cervical region of the spinal cord. The nerve supplies the ulnar flexor of the wrist, the ulnar half of the deep flexor of the fingers, the muscles of the little finger, the interossei, some of the lumbricales, the adductor, and inner head of the short flexor of the thumb. Its sensory area is the ulnar side of the hand, back and front, generally more extensive on the back (two fingers and a half) than on the front { one finger and a half) . The course of the nerve, superficial behind the elbow and at the wrist, renders it liable to separate injury. It is often implicated in wounds of the forearm, and about the elbow-joint, by dislocations of the shoulder and elbow, enlargement of the elbow bones, and by fractures of the bones of the forearm. It is occasionally the seat of neuritis, and, like the musculo- spiral nerve, it is sometimes paralysed by pressure. At the elbow the projecting bones preserve the nerve from direct pressure ; although Duchenne describes paralysis in men who, while at work, rest the bent •elbow on a hard substance, this mechanism is certainly rare. It is much more common for the nerve to suffer in long- continued flexion of the NERVKS OF THE ARM. 109 elbo-w, without external pressure; and from this cause the nerve is sometimes paralysed during sleep.* I have three times seen a sleep palsy of the ulnar nerve. The tension may set up neuritis, and is especially effective if the resistance of the tissues to morbid influences is lessened by general ill-health. Many persons must have noticed that if, when out of health, they sleep with the elbow bent, they wake with tingling, and even loss of feeling, in the region supplied by the ulnar nerve, although this may not happen when they are in good health. If the ill-health is profound, as in an acute illness, local neuritis of considerable intensity may be set up. Thus a lady, a few days after childbirth, who was prostrated by a long, exhausting labour, noticed tingling in the side of the hand, and whenever she bent her elbow, a sensation " as if she had knocked her funny-bone." Paralysis of the muscles supplied by the ulnar nerve followed in a few hours, and in a fortnight there was distinct wasting. When I saw her, six months later, the ulnar nerve behind the elbow was distinctly thickened. She had had a similar but more transient attack after a previous con- finement. A similar palsy has occurred during the course of typhoid fever, and both nerves have been known to suffer (Bernhardt). In such conditions not only is the tissue health lowered, but warning sensations are often unperceived. Actual cysts of the nerve have been described by Bowlby and zum Busch. The importance of the interosseal flexion of the fingers for many actions, such as writing, renders palsy of the ulnar nerve peculiarly dis- abling. Several illustrations of the svmptoms have already been given (pp. 42 and 43). In flexion of the wrist the hand deviates towards the radial side, and persistent distortion may take place. Adduction of the thumb is lost, and so are most movements of the little finger. The fingers cannot be flexed at the first or extended at the other joints, but the loss is slighter in the first two fingers than in the others, because their lumbricales are supplied by the median nerve. In time the opponents of the interossei, by their contracture, lead to over-exten- sion of the first phalanges and flexion of the others ; the " claw-like hand " is produced (see p. 43), but this is less complete than in cases of progressive muscular atrophy, on account of the escape of the first two lumbricales. When the palsy is imperfect it may be possible to extend the second and third phalanges, if the first can be over-extended and an advantage thus given to the interossei by the lengthening of the course of their tendons, just as in partial paralysis of the long extensors they may be able to extend the digits if the wrist is flexed, but not if it is extended. In lasting damage the hypothenar eminence may disappear, the palm is hollow, the thenar muscles that remain * H. Eraun (' Deutsch. med. Wocli.,' 1894) believes that in sleep the nerve is compri'ssed, not at the elbow but at the shoulder, particularly when the arm is abducted and carried backwards, so that the hands are crossed behind the head. A similar effect may result from the arm being held in this position in an operation, ».g. the removal of a breast. 110 SPINAL NEEVES. stand out, and the opponens may cause a slight forw^ard rotation of the thumb. The loss of sensation, as in the case of the other nerves, varies much, both according to, and irrespectiye of, the degree of lesion of the nerve. Subjective sensations are common, with and without anaes- thesia, and those who have had neuritis are sometimes unable to bend the elbow for a few minutes without a sensation of tingling in the area supjDlied.* The diagnosis of disease of the ulnar nerve is easy. A difficulty is occasionally caused by the circumstance already mentioned, that dis- ease at the lowest part of the cervical enlargement may cause sym- ptoms limited to the region of this nerve, but a knowledge of the fact is usually sufficient to prevent an error .f Combined Palsies op the Nekves of the Arm. — ^Paralysis in the region of two or more of the nerves of the arm is very common, and results from many causes. It may be due to disease of the spinal cord or of the nerve-roots within the spinal canal, but with these we are not now concerned. The most frequent causes outside the spinal canal are the following: — (1) Morbid processes in the neck, affecting the nerve-roots outside the spine or the upper part of the brachial plexus, especially growths and exostoses. (2) Diseases of the plexus itself, neuritis or injury, dislocations of the shoulder, the stretching by a sudden wrench of the arm, if or actual rupture of the nerves entering the plexus by great local violence. § (3) Fractures of the bones. (4) Neuritis, which may ascend a nerve of the arm to the part of the plexus whence it comes, and there spread ; or neuritis of the plexus may be primary and of various extent, "neuritis migrans." The last, ascending neuritis, occurs when an injury of a single nerve ia followed by an extension of the motor and sensory symptoms to the regions supplied by other nerves. This can only be explained by an ascending neuritis reaching the junction of the nerves at the brachial plexus, and there spreading, of ten in what seems a random manner. Thus a lady cut her wrist so as to leave a scar an inch long, over the position and in the direction of the median nerve. The injury caused paralysis and wasting of all the muscles in the hand * Atisesthesia of the region supplied by the ulnar and external popliteal nerves is a not infrequent symptom of general paralysis of the insane and tabes. In the ulnar it was first described by Biernacki, ' Neurol. Centralbl.,' 1894, in the external popliteal by Sarbo. See Savbd and v. Deky, ' Pest. Med.-Chir. Presse,' 1897. + Poncet ('Comptes Rcndus,' 1888) describes a manual paralysis in glass-blowers (hooked-band, main en crochet) which closely simulates ulnar palsy, from which it is to be distinguished by the freedom of the thumb and the absence of aneesthesia. X Bowlby, loc. cit., p. 225. § Rieiler (' Munch, med. Wochenschr,,' 1893) describes a paralysis affecting mainly the circumflex and musculo-spiral nerves of the left arm, and occurring especially in bricklayers from the pressure of the hod upon the shoulder. NERVES OF THE ARM. Ill supplied by this nerve. This palsy was followed by a gradual loss of power, with diminished faradic irritability, in the long extensor of the fingers, the ulnar flexor of the wrist, and also by defect of sensation in the skin supplied by the ulnar nerve. Hence the neuritis must have ascended to the plexus and there have spread along each root of the median nerve. Again, a woman cut her right hand with a broken stone bottle, along the hyiDothenar eminence. Three weeks after- wards the muscles of the hand supplied by the idnar nerve gradually became paralysed, with wasting and loss of irritability, and in the area of the skin supplied by the nerve there was first tingling and then diminished sensibility. Burning pain spread up the front of the forearm, and inner side of the upper arm to the axilla ; all the fore- arm muscles lost power, the flexor carpi ulnaris, and the flexor sublimis digitorum in greatest degree; the tingling and lessened sensibility spread to the fingers supplied by the median nerve, and the abductor pollicis wasted. In this case also there must have been an ascending neuritis of the ulnar, spreading to the median at the brachial plexus. The extension is sometimes only in the neighbourhood of the cause. A whitlow on the thumb was followed by extreme wasting, with reaction of degeneration in all the thenar muscles supplied by the median. But a case is on record in which a nodular inflammation commencing in the ulnar nerves apparently spread up to the sympathetic* The brachial plexus is occasionally the seat of a primary neuritis. This is described in a separate section (p. 119), as it is a defined and important disease. In dislocation of the shoulder the displaced head of the humerus may damage the nerves. In subcoracoid dislocation they are necessarily compressed. The extent of injury varies greatly ; only one nerve may suffer, or not one may escape. Every muscle of the arm may be para- lysed, from the deltoid downwards. In most cases the injury is severe in degree; there is rapid wasting of the muscles, with the reaction of degeneration, and there is a great tendency to the occiu-- rence of trophic changes in the skin. It was in a case of this character that the forearm and hand were covered with blisters from the appli- cation of water that seemed merely warm to a healthy hand (p. 79). Fracture of the humerus may damage both the musculo -spiral and ulnar nerves, rarely the median. Fracture of the bones of the forearm often injures both the median and ulnar nerves. Injuries to the neck sometimes cause a partial paralysis of the arm of peculiar distribution, the special characters and significance of which were first made known by Erb.f A similar paralysis may come on apart from injury. The muscles affected are the deltoid, often the supra-spinatus and infra-spinatus, the biceps and brachialis • Remak, « Deutsch. Klinik,' 1864, p. 159. t Heidelberg Society, 1874, 'Ziemssen's Handbuch/ 1874, Bd. xii, pt. 2, p. 509; Bee also Bernhardt, ' Zeitscb. f. kl. Med.,' 1882, Bd. iv, p. 415. A previous descrip- tion by Uui lienne in 1885 bad escaped notice. 112 SPINAL NERVES. anticus, and tlie supinators. Erb found tliat fhere is one spot between tlie scaleni, corresponding to tlie sixtli cervical nerve, at wMcli electrical stimulation puts all tliese muscles ia action. Hoedemaker, vrlio has described two cases of this palsy, finds the motor point in a line drawn from the sterno- clavicular articulation to the seventh cervical spine, 1-5 centimetres from the edge of the trapezius. The palsy is appa- rently dependent on disease of the roots of the fifth and sixth cervical nerves, and the fifth, it will be remembered, receives a twig from the fourth.* Budingerf and Graupp| have recently shown that in forcible elevation of the arm some backward rotation of the clavicle occui-s, Ftp. 55. Fig. ofi. Pi&. 57. Pig. 55. — Combined palsy of deltoid, snpra-spinatns, and infra-spinatns, from a fall on the shoulder. Figs. 56, 57. — Left hand of a patient suffering from a growth beside the lower cervical spine compressing the nerve-roots. There was ansesthesia of all parts supplied by the brachial and cervical plexus. The arm was adducted, the elbow flexed, the hand in the posture shown, flexion of first, extension of second, strong flexion of last phalanges, the first phalanx of the thumb over-extended, the second flexed. Rigidity extreme, and an attempt to overcome it caused great pain. There was also some contractare of the foot (equino-valgus). compressing the fifti and sixth cervical nerves against the first rib. The fact that in this case the nerve-fibres are simply contused and not broken will no doubt account for the frequency of recovery from this form of paralysis. Besides injuries, this group of palsies may result from non-traumatic processes, probably from neuritis, and also from • Erb referred the palsy to disease of the sixth nerve. The experiments of Perrier and Yeo point to the fifth and fourth roots as those innervating these mnscles, but his subsequent correction indicates the fifth and sixth (see p. 99, foot- uote). t ' Arch. f. klin. Chir.,' 1894. J ' Centralblatt f. Chir.,' 1894. NERVES OP THE AEM. 113 growtlis in tM3 situation. Dxich.enne, Seeligmiiller, and otliers have also described paralysis of similar distribution produced in infants during birtb, either by pressure from the position of the ai-m, or by traction on the neck with the finger or hook during turning. Dis- location of the shoulder during delivery may cause very extensive damage to the plexus. Permanent paralysis of each arm was the result of bilateral dislocation caused by a midwife dragging a ehild out by the two arms.* Most obstetrical cases slowly recover. Those due to injury in adult life are often severe ; the symptoms continue for a long time, and may be permanent. A paralysis complementary to that of Erb, in which the muscles escape which suffer in that form, results from disease of the nerve- roots below.f It is often associated with ocular symptoms, such as narrowing of the pupil and palpebral fissure. Morbid processes connected with the bones of the cervical spine sometimes produce combined symptoms of irritation and palsy of the nerves of the arm, pain, hypersesthesia, ansesthesia, paralysis of muscles, and extreme muscular contractures, often very irregular in distribution (such as are shown in Figs. 56, 57). I have several times known sensory symptoms in the arm to be due to a chronic syphilitic celliditis beside the vertebrae, causing deep-seated induration and severe compression of the nerves ; in each case it was completely removed by antisyphilitic treatment. Growths at the part may also compress the subclavian artery, and the weaker pulse may aid the diagnosis.^ DiAQNOSis. — The diagnosis of diseases of the nerves of the arm has been for the most part sufficiently considered in connection with the special nerves. It consists chiefly in an application of the facts there stated. One or two more general considerations deserve, however, a brief mention. Some diseases of the spinal cord are first manifested in the arm, by muscular palsy, wasting, or by ansesthesia. The risk of error is prevented, in most cases, by the absence of any corre- spondence between these symptoms and the functions of special nerves, by the absence of any indication of morbid processes in the neighbourhood of the nerves, and by the presence of other signs of disease of the spinal cord. It has been mentioned that disease in the lowest part of the cervical enlargement may be manifested only in the region of the ulnar nerve, the lowest in origin of all the brachial nerves. Such disease is, however, usually bilateral, and secondary to disease in the dorsal region of the cord, the indications of which have • Danchez, * Ann. de Gyn.,' &c., Oct., 1891. Double palsy in adults is occasioaally Been, as in a case recorded by Bernhardt, in which the arms were pulled on for an hour to steady tlie patient during the operation of oSphorectomy. t It has been termed " Klumpke's paralysis," because investigated in Vulpian's laboratory by Mdlle. Klumpke in 1883 (see • Zeitsch. f. Nervenh.,' 1891) ; it had, however, been described long previously, notably in 1827 by Flaubert. J Bowlby, loc. cit. VOL. I. 8 114 SPINAL NERVES. preceded the symptoms in tlie arm. A knowledge of these facts, an a careful consideration of the distribution and course of the symptoms, will rarely leave the observer in doubt. Treatment. — There is little in the treatment of the diseases of the nerves of the arm that requires special mention. The chief measure is the treatment of the cause of the paralysis. Any present source of pressure must be removed as far as possible. The ends of a divided nerve must be sutured. It is remarkable how quickly this has some- times been followed by the restoration of conducting power. The posture of the arm must, in all < ases, be such as to avoid tension on an injured or inflamed nerve. The treatment of neuritis is described in the next section. Electrical stimulation of the muscles is of great importance in a.ll cases of severe damage to the nerves. Even in old and stationary cases it sometimes starts some improvement. Nerves of the Lowek Limb. Disease of these nerves is far less common in the lower than in the upper limb, with one important exception, — the primary disease of the sciatic nerve that goes by the name of " sciatica." This affection is reserved for separate description. The nerves of the leg are derived from the lumbar and sacral plexuses. The lumbar plexus, consisting of the first three and a half lumbar roots, supplies the skin of the lower part of the abdomen, of the front and sides of the thigh, of the inner side of the lower leg and foot. It supplies also many muscles — the cremaster, those that flex and adduct the hip-joint, and those that extend the knee. Its branches for the leg are the obturator and anterior crural nerves. The sacral plexus consists of the fifth lumbar root and half the fourth (lumbo-sacral cord) and the first four sacral nerves, of which, however, only the upper three have to do with the leg. This plexus innervates the extensors and rotators of the hip, the flexors of the knee, and all the muscles that move the foot, together with the skin of the gluteal region, the back of the thigh, the outer side and back of the lower leg, and most of the foot. Its chief nerves are branches to the outward rotators of the hip, the gluteal nerve, and the small and great sciatic. The results obtained by Ferrier and Yeo (see p. 99) on stimulating the roots o£ the lumbar and sacral plexuses in the monkey may be thus summarised : Lumbar I and II. Lower abdominal muscles (not cremaster). III. Psoas and iliacus, sartorius, extensors of knee; (flexion of hip and extension of leg). IV. Glutei, adductors, extensor cruris, peroneus longus ; (extension of hip and knee, elevation of outer side of foot). V. Glutei, hamstrings, and all the muscles in front and back of lower leg ; (rotation of thigh outwards, flexion and rotation inwards of leg ; extension of foot with elevation of outer edge ; flexion of distal phalanges of toes). NJSEVJiS OF THE LEG. llJ> Sacral I. Hamstrings, calf mnscles, long flexor of toes, intrinsic muscles of foot; (slight outward rotation of thigh, flexion of knee, extension of foot, adduction of great toe, flexion of first phalanges of all toe» and of both phalanges of great toe). II. Intrinsic muscles of foot; (" interosseal " flexion of toes, similar to the last). These results cannot be simply applied to man. For instance, it is certain that in man, one flexor of the hip, the psoas, and the cremaster, are largely innervated from the second lumbar, but no indication of the action of either of these could be observed on stimulating this root in the monkey. The distribution of the sensory fibres of the nerve-roots is considered in the chapter on the Spinal Cord. The Lumbar plexus itself is sometimes damaged by growths in the abdomen (especially by those that spring from the lumbar glands) and by psoas abscess, while the nerve-roots may suffer in disease of the bones of the vertebrae and in meningitis. The plexus may also be in- vaded by inflammation ascending the lumbo- sacral cord from the sacral plexus, and it is occasionally the seat of spontaneous neuritis. The obturator nerve is rarely affected alone ; it has been sometimes damaged in the course of parturition. The anterior crural nerve has suffered from the same cause, and is sometimes injured by wounds of the groin or thigh, or by dislocation of the hip-joint. Symptoms may be limited to it in disease of the nerve-roots, and as in injury or growths of the vertebrae, its paralysis occasionally follows acute or subacute inflam- mation of the knee-joint. Of the ijiterf erence with movement that may result, the paral} sis of the flexors of the hip depends on the position of the disease. This paralysis is total only when the lumbar plexus is damaged. Disease of the anterior crural nerve, within the abdomen, does not affect the psoas, but may paralyse the iliacus, and so weaken, without abolishing, the power of flexion. The chief symptom of disease of this nerve is the loss of power in the extensors of the knee, and the wasting of these muscles, together with loss of the knee-jerk which results from the interruption of the reflex arc. The effect of these palsies on movement is very serious (see pp. 46, 47). Anaesthesia involves the whole of the thigh (except a strip along the middle of the back), the inner side of the leg and foot, and the adjacent side of the first and second toes. In many cases the paralysis is incomplete, and the symptoms present corresponding variation. Irritation of the nerve may cause severe pain in the region supplied by it. This is sometimes an early symptom of a growth near the spine. The pain in neuritis of the plexus may extend along the course of the ilio-hypogastric, ilio-inguinal, and genito- crural nerves, to the lower part of the abdomen and groin. Impairment of sensation in an area on the front of the lower half of the thigh is occasionally met with as an isolated symptom, usually in men in the second half of life. It comes on without pain, and may pass away after months, or may persist for years. The loss is greatest in the 116 SriNAL NERVES middle of the region, but the transition to nonnal sensibility is well defined ; its origin and nature are mysterious, except that the subjects of it are usually gouty. It seems to have little significance. Paralysis of the obturator nerve causes a loss of the power of adduc- tion of the thigh, so that the patient cannot put one leg across the other. Rotation of the thigh outwards is interfered with, but in slighter degree than adduction. The effect of these palsies (described on p. 47) is far less serious than is the disability which results from disease of the anterior crural. There is disturbance of sensation along the inner side of the thigh and knee ; an obturator hernia may press upon the nerve, giving rise to paresis of the muscles which it supphes. and burning pains in the region of its sensory distribution. The superior gluteal nerve occupies an intermediate position between the two plexuses, arising as it does from the lumbo-sacral cord, which descends from the fourth and fifth lumbar roots. Its disease, which is very rare in isolated form, causes paralysis of the gluteus medius and minimus, with a loss of abduction and circumduction of the thigh (see pp. 45, 46). The Sacral plexus is sometimes damaged by growths in the pelvis, by pelvic inflammation of various kinds, and by compression during parturition. In the child it may be damaged by traction on the legs. It is also often the seat of neuritis, which, however, less frequently begins in the plexus than ascends to it from the sciatic nerve. Apart from spontaneous neuritis, which will be separately desmbed, the sciatic nerve outside the pelvis is occasionally injured by woiMids, rarely by dislocations of the hip, often by disease of the bone, and by adjacent morbid growths. It is also a relatively frequent seat of neuroma. Of the terminal branches, the external popliteal, by its superficial course, and proximity to the hard bone, suffers from traumatic lesions of various kinds ; it is also prone to spontaneous neuritis. This nerve is homologous with the musculo- spiral nerve of the arm, and presents an analogous liability to disease ; it occasionally suffers in persons whose occupations entail much kneeling. The pos- terior tibial nerve is more secure in its deeper course, but may be damaged by fracture of the bones. The symptoms of palsy of the sciatic nerve vary much in their character, according to the position of the disease. The small sciatic is implicated only when the mischief involves the pelvic plexus, and it scarcely ever suffers alone. The effect is palsy of the gluteus maximus, which interferes with rising from a seat more than with walking (see p, 45). There is also anaesthesia of the skin in the middle third of the back of the thigh, and in the upper half of the caK, A lesion of the sciatic nerve, near the sciatic notch, paralyses the flexors of the leg (which are also extensors of the hip ; seep. 47), and all the muscles below the knees. Often the lesion is below the upper third of the thigh, and then the flexors of the leg escape. Even when all the muscles below the knee are paralysed, walking is still possible, the foot NERVES OF THE LEG. 117 being raised by over-flexion of the hip. Th© anaesthesia that results from a lesion of the nerve below the origin of the small sciatic, involves the outer half of the leg, the greater part of the dorsum of the foot, and all the sole, but the leg may escape, perhaps through union "with other nerves. The symptoms of disease of the branches are as follows : That of the external popliteal or peroneal nerve causes paralysis of the tibialis anticus, long extensor of the toes, peronei, and extensor brevis digitorum. The effect of this is a loss of all power of flexing the ankle and of extending the first phalanx of the toes (see p. 50). The foot cannot be raised from the ground in walking, and talipes equinus ultimately results (Fig. 30, p. 51), which may be attended with persistent flexion of the first phalanges of the toes from contracture of the ujiopposed interossei. There is also anaesthesia on the outer half of the front of the leg, and on the dorsum of tbe foot.* Disease of the internal 'popliteal nerve paralyses the popliteus, calf muscles, tibialis posticus, and long flexors of the toes, as well as the muscles of the sole. In addition to the disability which characterises paralysis of the plantar muscles, there is loss of the inward rotation of the flexed leg if the disease is so high as to involve the branch to the popliteus, and there is also loss of the power of extending the ankle- joint. Talipes calcaneus resxdts (Fig. 28, p. 50). The sensory loss is on the outer lower part of the back of the leg, and on the sole, but varies much. The plantar nerves rarely suffer alone. A lesion of the internal nerve causes anaesthesia on the inner part of the sole, and plantar surface of the three inner toes and half the fourth, together with paralysis of the short flexor of the toes, the plantar muscles of the great toe (except the adductor), and of the two inner lumbricales. Disease of the external nerve produces anaesthesia of the skin on the outer half of the sole, the Kttle toe and half the fourth, paralysis of the flexor accessorius, the muscles of the little toe, all the interossei, the two outer lumbricales, and the adductor of the great toe. The effect of this palsy (see p. 52) is serious, since the toes cannot take their proper share in propelling the body forward in walking, and they gradually become flexed at the last two joints and extended at the others, from the contracture of the opponents of the interossei, — ^a position of the toes that causes serious inconvenience in walking. Diagnosis. — The diagnosis of diseases of the nerves of the leg is determined by the same general principles as those that have been mentioned as applicable to the nerves in general, and to the nerves of the arm in particular. The limitation of the symptoms to the functional areas of individual nerve-trunks, the evidence afforded by nutrition, irritability, and reflex action that the muscles are separated * Anaesthesia in the district supplied by this nerve may be a symptom of various progressive nervous diseases; it was first described in this connection by Sarbo (see p. 110, footnote). 118 SPINAL NERVES. from the spinal cord, tlie implication of tlie sensory functions, and often tlie tenderness of the affected nerres, indicate, in most cases, the seat of the disease. To these signs are often added other indica- tions of a local cause, corresponding, in its position, with the nerve to which the symptoms point. The relation of nerve-trunks to nerve-roots, although by no means simple, is certainly less complex in the case of the nerves of the leg than in those of the arm. This is especially the case in the lumbar plexus, and it leads to an occasional difficulty in diagnosis. Pressure on the spinal cord, for instance, at the level of the origin of the fourth lumbar roots, may cause symptoms identical with those of a partial lesion of the anterior crural nerve. For instance, I have known para- lysis of the extensors of the knee, loss of the knee-jerk, with anaesthesia in the front of the thigh, to be the result of a gumma at the side of the cord at this level. But other evidence of a spinal lesion is rarely absent under such circumstances, and in this patient a foot-clonus, due to the pressure on the pyramidal fibres, left no doubt as to the situation of the disease. Another difficulty arises from the long course of the nerve-roots in the cauda equina, disease of which may simulate that of the nerves of the leg. Implication of this region is most commonly due to syphilis, trauma, congenital defects (spina bifida), or new growths.* But the symptoms are commonly bilateral in consequence of the prox- imity of the nerve-roots of the two sides. In all cases in which symptoms are bilateral (unless there is evidence of a disease known to cause symmetrical lesions, such as multiple neuritis), the suggestion is that the disease is situated where the motor or sensory paths of each side are so near that they can be affected by a single lesion, i. e. that the disease is within the spinal canal. But here, as in other cases, we cannot reverse our diagnostic rules. Disease of the spinal cord does not always cause bilateral symptoms. A limited lesion of one anterior cornu may be so placed as to pa'ralyse the muscles supplied by a single nerve, and a doubt may be felt as to the central or peri- pheral origin of such palsy. The muscles supplied by the anterior crural nerve, and the muscles in the front of the lower leg supphed by the external popliteal, are those of which the central palsy most often leads to doubt. The mode of onset, the presence or absence of sensory symptoms, the rarity of acute spinal palsy except in child- hood, and of nerve-lesions except in adult life, the wider initial pre- valence of the palsy in acute, and its later extension in chronic, cornual disease, — these suffice as a rule to remove any doubt. It is important to remember that the pressure of a growth may cause either a chronic or an acute affection of the nerves. The chronic symptoms result from compression ; the acute from a neuritis set up by the pressure and irritation. Tkeatment. — The treatment of disease of the nerves of the leg * See Thorbura, * Brain,* 1888 ; Fr. Schulze, ' Deutsche Zeitschr. XervenheilkV 1894, vol. V. BRACHIAL NEURITIS. 119 does not differ from that of disease of the nerves of the arm. More care, perhaps, is needed to avoid increasing present mischief, or inviting a relapse, by exposure to cold or bj fatiguing exertion. More care is also needed to obviate the tendency to secondary contractures in the case of palsies of long duration, and in those attended by pain in which the patient seeks ease in postures to which the muscles only too readily adapt themselves. The contraction of the hamstrings, from con- stant flexion of the knees, occurs very readily and is most troublesome ; that of the calf muscles, which occurs when the flexors of the ankle are paralysed, also constitutes a serious obstacle to walking after recovery. A little timgly care, by attention to posture, will often save a vast amount of later trouble. That of the calf muscles, however, which is due to the extension produced by the weight of the foot as the patient lies, cannot always be entirely prevented, but may be lessened hj a board or large sand-bag against \\hich the feet can rest. An outline is given elsewhere of the forms of local inflammation of these nerves, with special reference to the morbid process, on account of its important practical relations. (See Crural Neuritis, p. 133.) BRACHIAL NEURITIS. Besides the forms of inflammation of the nerves of the arm already described, a primary inflammation of the brachial plexus occurs in a form as well defined as sciatica, and equally meriting a separate description. This, however, need only include its special features; those that are common to other forms of neuritis have been already described. It is closely analogous to sciatica, and is usually a peri- neuritis, — a primary inflammation of the sheaths of the branches that enter and form the brachial plexus. Cases occur, however, in which the symptoms correspond in general character to the rest, but in which their distribution suggests that the n^rve-roots rather than the plexus are the seat of the inflammation, and pain about the spine supports the opinion. This form may be called Radicular Neuritis. Although its existence has not been established by pathological evidence, the symptoms mentioned admit of no other explanation. A knowledge of their significance is of great practical importance on account of the closeness with which they may simulate those of organic disease of the bones of the spine, or a growth in the spinal membranes. Causes. — The influence of gout in causing local neuritis is very conspicuous in the brachial form, with the special characteristic that this occurs chiefly late in life, verv often from the inherited disease, 120 BRACHIAL NEURITIS. and with greater frequency in females than any other form of neuritis ; their liability is at least equal to, if not greater than, that of men. Fiye sixths of the cases occur after fifty, and it may be met with up to extreme old age. In men there have usually been the ordinary manifestations of gout, but in women the tendency is often only indicated by the family history, and by previous muscular rheuma- tism, especially lumbago and sciatica, — which have seldom been abront in either sex. In one case the onset of the brachial neuritis occurred immediately after an attack of sciatica. Neuritis of the brachial plexus may also arise from trauma or the pressure of new growths, e.g. of a pressure on the posterior surface of the clavicle. Symptoms. — Pain, the great symptom of the inflammation of all mixed and sensory nerves, is greater in this than in most forms of neuritis. It is usually the first symptom, and lasts long after the inflammation is over; its severity, coupled with the age of most sufferers, renders the malady one of a peculiarly trying character. The first pain is often referred to a distance from the seat of the inflammation, perhaps because this begins at the plexus, where, at divisions, it is facilitated by motion, and the conducting fibres are readily reached and early irritated. Frequent seats for the first pain are the region of the scapula (sometimes beneath the bone) and the wrist or back of the forearm, with or without the hand. In other cases, however, the first pain is at the plexus itself, above the clavicle or in the axiUa, and these are the places in which it is commonly most intense throughout the attack. As the pain increases it extends along the course of the nerves of the arm, which the patient will often accu- rately indicate with his finger when tracing the lines of pain. The pain is sometimes sudden in onset and severe from the begin- ning ; more often it is at first occasional, or felt on certain movements, but, as it increases, it becomes more continuous, with variations that soon become paroxysmal. Ultimately there is always more or less dull wearying j)ain in the whole arm, but especially in the region of the plexus, varied by attacks of great severity. In these the pain is acute and lancinating, or stabbing, or burning ; it usually takes the course of the nerves, diffusing itself from them, and often passing to the side of the chest and to the neck, — seldom to the head. The pain often varies in character according to intensity ; at the height of the paroxysm it may be sharp and stabbing, or such darting pains may be superadded to a more diffused burning pain, which lasts longer than the acute pain, and may be followed, as the paroxysm subsides, by general tingling of the skin of the whole limb. The paroxysms are induced by movement or occur spontaneously. In slighter cases the pain is paroxysmal only, and then the relation to movement is a very conspicuous feature. Although it is seldom confined to movement, this never fails to induce severe pain, and the patient avoids the slightest use of the limb. Elevation of the arm especially causes distress. With the pain there is usually undue sensitiveness of the skin. DIAGNOSIS. 121 which may be much increased during and after the paroxysms. Loss of sensation is rare, and is met with only in cases that are not only severe but prolonged. The two may concur, as " anaesthesia dolorosa." The muscles usually present the flabbiness and slight wasting common in neuritis, but the damage to the motor fibres is seldom sufficient to cause considerable atrophy. Sometimes, however, there is enough damage to cause wasting of some group of muscles, with the reaction of degeneration. This is most frequent in the radicular form, in which the damage is to the upper part of the plexus and nerve-roots. There may then be anaesthesia of the shin over the affected muscles. It is difficult to ascertain the existen<'e or the amount of motor weakness; effort induces pain so readily that the patient can seldom be induced to make an attempt to exert force. Power is often said to be almost lost, when it is probably greater than is believed. Besides the muscles, the subcutaneous tissue of the limb may also waste, and the skin may become thin and shining, and present the aspect already described. Subcutaneous oedema is also common, and in one case erythema nodosum was found.* Arthritic changes in the joints of the fingers are almost constant in the cases that occur in later life ; the adhesions may be permanent. Diagnosis. — Few maladies, as a fact of experience, give rise to greater diagnostic difficulty. This is due to several causes : the affection is rare ; its symptoms are sometimes equivocal ; the subjects are usually in the degenerative period of life, when ma.ny obscure diseases attended with pain in the arm occur to the mind of the physician ; and lastly, the distinction between neuralgia and neuritis is often difficult, although less so than is supposed. The last is, indeed, the mosb frequent source of error. The most severe and characteristic cases of brachial neuritis are frequently mistaken for pure neuralgia, on account of the paroxysmal character of the more severe pain, and because the characters of neuritis are unfamiliar. The points to deter- mine the diagnosis are those described in the sections on neuritis and neuralgia ; — the degree of persistent tenderness of the nerves and the influence of movement, together with the history of the attack, the locality of the pains, and especially any evidence of damage to the fibres. A history of neuralgia in the person or the family is of slight weight only ; the tendencies to true neuralgia and to neuritis are often combined, and each is a frequent result of gout. A far greater diffi- culty is presented by the cases in which the inflammation remains slight and is confined to the plexus, affecting branches where the con- ducting fibres can be so irritated as to cause distant pain, which then becomes the leading symptom. This is often paroxysmal, and, when on the left side, may radiate to the chest and be associated with dis- turbed action of the heart. Angina pectoris is often thought of in such cases ; and here again the degenerative age may increase the difficulty by leading to the presence of some coincident disease of the * V. Fraiikl Hoihvvart, ♦ Wien. klin. Wocbeuschrift,' 1897, No. 1. 122 BEACH I AL NEURITIS. heai-t, or by making true angina not unlikely. The distinction afforded by the nerve-tenderness is tlien of great importance, because the dis- propoi-tionate amount of tenderness (compared with the amount of pain) is more emphatic in slight than in severe cases. Persistent tenderness with only paroxysmal pain should always suggest neuritis. When the position of the pain is cai-ef uUy examined, its relation to the plexus and branches is often clnar. It is important to remember that all nerve-pains in the brachial region on the left side have a tendency to resemble anginal pain in distribution, and to be associated with cardiac distress. Probably there is some peculiar tendency for pains in this part to disturb the action of the heart; a common physio- logical relation may underlie both the nerve-pains of cardiac angina and the cardiac symptoms of nerve-pains. Hence this secondary dis- turbance does not neutralise the significance of the special signs of neuritis. In some cases of the slighter class, the pains suggest the idea of an aneurism ; in many cases of brachial neuritis this diagnosis has been made, and the patient has had to endure months of mental distress, for which no real cause was in existence. Such a suspicion, in the absence of special signs, such as pressure- symptoms, should only be entertained if the pains are persistently and increasingly severe, and unaccompanied by any considerable amount of tenderness. In all these cases, moreover, the presence of the gouty diathesis may be allowed weight in the diagnosis. The muscular wasting, slight in degree, added to the arthritic changes, gives rise to a condition which may be mistaken for a primary joint affection with secondary " arthritic atrophy " of the muscles. It is only in the chronic stage that this error is possible. A careful attention to the history of the case will show its real nature, but with- out this attention the mistake is easy, and it is often made. Prognosis. — Except in its most trifling degree, brachial neuritis is a tedious malady ; the duration of every severe case is to be measured by months, and often more than a year elapses before the patient is free from pain. Post-neuritic pain is always more prolonged in the old than in the young, and the age of the subjects, together with the amount of damage to the nerves, causes suffering to last longer than in almost any other form. To these causes also must be added the degree of sensitiveness of the affected nerves, exceeded only by that of the fifth nerve, and also the mobility of the parts in which the plexus lies ; this involves a continued cause of irritation, brought into play as soon as the diminution in the severer pain permits the patient to employ the long useless arm. Eelapses, moreover, are not uncommon. Recurrence may take place after moderate attacks, but seldom occurs after those of extreme severity. Eiccovery from the consequences of the inflammation is not always complete. The limb often remains smaller and feebler, with a liability to tiugHng and to cramp, and also to neuralgic pains under the in- fluence of changes in the weather, &c. But the most serious conse- SCIATICA. 123 quences are the alterations in the ^jints. These are very frequent : the fixation occasioned by the pain permits, and the tendency to perverted nutrition produces, adhesion between the ai^ticular surfaces, in consequence of which the movement becomes permanently re- strained. It is probable, moreover, that the constitutional state which imderlies the primary malady often increases the degree of these joint-alterations. The shoulder, wrist, and fingers are the joints that are most frequently thus rendered stiff. The interference with the movement of the fingers is especially troublesome ; the joints become painful in consequence of the unavoidable strain on the tissues when an attempt at use is made. Treatment. — The treatment that has been described, as needed in neuritis generally, is suitable also for this form, and its details need not here be repeated. Abstinence from movement is of great import- ance ; the occurrence of stiffness of the joints in consequence of the immobility of the limb must be risked. It is doubtful, indeed, whether the tendency to this is much increased thereby, for the effect of pain, in preventing sufficient movement to maintain the normal state of the joints, is not materially increased by rest otherwise enforced ; whUe the difference between a little movement and none, during the acute stage of the affection, is enough to make a considerable difference in the effect on the inflammation of the nerves. The influence of cocaine, injected under the skin, is very beneficial, but it is needed frequently in severe cases, and two injections (each -^ — |- gr.) may be given daily during the height of the disease. It is important that the nerves should not be irritated by massage in the state of active inflammation ; indeed, no therapeutic measure which occasions prin can do as much good as harm. After the tenderness has subsided, gentle rubbing, such as is agreeable, may be employed with advantage. Electricity is only needed for muscles that present the reaction of degeneration, or to aid in removing after-pains. In one severe case, associated with multiple neuromata of the skin, relief resulted from excision of the outer and inner cords of the plexus. The excised portions showed some interstitial neuritis.* SCIATICA. The most frequent of all forms of inflammation of a single nerve, unilateral, and primarily of the connective-tissue elements, and especially of the sheath, is that of the sciatic. The fact, coupled with the prominent character of the painful and disabling symptoms, have raised "sciatica" into a conspicuous position among diseases of * Mauiy and Jiihiiiig, ' Amer. Journ. of Med. Sci.,' 1874; a similar case of septic origin recorded by S.uids and Seguin was not cured by excision of the plexus. 124 SCIATICA. the nerves, and indeed among diseases generally. This renders desirable a specially full description of the malady, fuller than strictly corre- sponds with its subordinate position as a variety of neuritis. As the word " sciatica " is commonly used, it is a general designation for all affections of which the chief symptom is pain in the region of the sciatic nerve. In a stricter use of the word, however, it is applied to painful affections of the nerve not due to any morbid pro- cess outside it ; thus limited, it practically corresponds to inflamma- tion of the nerve. Two varieties may be distinguished, however, according as the process in the nerve is excited by primary disease in its vicinity, " secondary " sciatica ; and " primary " sciatica, when the pain is the expression of disease beginning in and related to the nerve itself. Primary sciatica is sometimes regarded as a neuralgia. This view is in the main erroneous ; the vast majority of cases of sciatica are really cases of true neuritis. Causes. — Sciatica is far more frequent in males than in females ; the proportion has been very variously estimated. The best evidence of the incidence of the disease is that presented by the patients treated at the Devonshire Hospital, Buxton, of which an analysis of 1000 cases has been made by Dr. E. V. Gibson.* The percentage of males is 88'4, of females ll'6,t giving a ratio of 5 to 1, which is probably very near the truth. The disease is unknown in childhood, and rare in the second decade of life. It does not, indeed, occur under fifteen ; in more than half the cases it begins between thirty and fifty, and between fifty and seventy in a quarter. Having regard to the smaller number of persons living, the frequency of its occurrence must be regarded as at leadt as great in late as in middle life. J No special influence of sex is distinguishable in the decade forty to fifty : the proportion of males to females is that of the whole series. Under forty a smaller, and over fifty a larger proportion of females suffer. Exposure to the exciting causes is probably more common in males during middle life, when also the malady is promoted by the various accelerating influences which aid the active development of its chief constitutional cause— gout. But it must not be forgotten how comparatively small is the actual number of cases in women. Underlying most cases of sciatica is either the state of definite gout, or that rheumatic diathesis in which the fibrous tissues suffer, especially those that are connected with the muscles, a form closely connected with common gout by co-existence or descent. It occurs frequently in those who are themselves gouty, who present the personal characteristics of the disease, and have fostered it by mode of life. It occurs also in those of * Dr. E. Valentine Gibson, ' Lancet,' 1893, vol. i, p. 860. t 884 femiiles, 116 males, in the 1000. X The percentage distribution of the 1000 cases at Bnxtoii is as follows: — The age is taken at which the first attack commenced. Between 15 and 20, 14 eases; 21 to 30, 159 cases ; 31 to 40, 310 cases ; 41 to 50, 248 cases (one quarter of the whole) ; 51 to 60, 187 cases ; 61 to 70, 71 cases ; 71 to 80, 11 cases. CAUSES. 125 gouty inheritance, but who themselves have been abstemious, and sometimes present a weakly constitution — thin, pallid, neurotic. The latter have often suffered from acute articular rheumatism in earlier life. It is among them that the most severe cases are met with, in which the inflammation spreads to other nerves, or involves the sheath of the sciatic with other structures, and that it develops early in life, during, for instance, the second fifteen years. This constitutional state, with all its effects, is sometimes met with when there is only trifling evidence of inheritance. Some unknown influence seems to determine its development in intense degree as a congenital tendency, manifested by rheumatic troubles, various and severe, early in adult life — the sporadic occurrence of that which is usually inherited. There is no evidence of a direct causal relation to other consti- tutional diseases. Syphilis has been supposed in some cases to give rise to it, but the cases are rare, and the common cause can seldom be excluded. An exciting cause is to be traced in many of the cases. Exposure to cold is the most frequent. It is usually local exposure, as by wet boots, standing in water, &c. ; sometimes, however, a general chiU of the body determines an attack. The exposure to cold may be even more direct, as by sitting on wet grass. Draughty water-closet seats are answerable for some cases. The neuritis often arises by the exten- sion of an adjacent rheumatic affection of the fibrous tissue, especially of that form of " lumbago " which involves the fibrous attachments of the muscles at the back of the sacrum, less commonly in its ordinary lumbar seat. This affection passes down from the sacrum, extending along the fasciae, to the nerve- sheath in the neighbourhood of the sciatic notch ; or passes forwards, over the crest, to the front of the iliac bone, and. spreads in the tissue about the lumbar plexus, and descends to that which covers the mass of sacral nerves from which the sciatic proceeds. (The fact is of much interest, because it shows that this form of fibrous rheumatism, of which we have only a very vague pathological conception, must be regarded as inflammation, since positive neuritis results from it.) The rhetunatic pain has usually existed for a few days only before the extension occurs, but sometimes a chronic affection, after existing as such for several weeks, spreads acutely. Mechanical disturbance sometimes excites the disease, and often co-operates with other influences. The pressure of the edge of the chair, in those who sit much, is the most frequent. Muscular over-exertion, suddenly compressing the nerve in the thigh, is occa- sionally effective. If the nerve is already tender, a strong contraction of the muscles at the back of the thigh, especially when the knee is flexed, and the muscles can freely shorten and widen, may produce acute pain ia the nerve, evidently by its compression. This cause is probably effective only in a predisposed person, or when there is already com- mencing neuritis 126 SCIATICA. Varions morbid processes within the pelvis may cause sciatica by compressing the sacral plexus, or by exciting inflammation which invades the nerve. Rectal and other tumours give rise to progressive pressure, and the inflammation excited descends the nerve, resembling the primary form. It may be an early symptom of a growth springing from the bone, as an enchondroma arising at the sacro-iliac synchon- drosis. Pelvic inflammation and injury during labour are occasional causes. A loaded rectimi may be the excitant, but is a rare cause, although apt to be recurrent when once effective. Lastly, the sciatic nerve may be secondarily involved in mischief that is outside the pelvis. The most frequent cause of this is disease of the bone, as disease of the hip- joint, especially senile rheumatic inflammation (Gribson). The proclivity of the fibrous tissue of this nerve to suffer primarily is due to its position and the exposure this involves, and to its con- nections, which facilitate the passage of inflammation to it. But there are cases with a strong disposition for fibrous rheumatism to fix itself in the tissues of the pelvis, sacral and lumbar regions; the nerves cannot escape implication ; whether the sciatic suffers early or late, and in what degree, depend on secondary conditions, but it is specially liable on account of the anatomical relations of its origin. The mass of the " sacral plexus " is prolonged into it, and the mem- branes covering this, and its branches, including the lumbo-sacral cord, are very liable to be the seat of such inflammation, wide- spread, fixing itself irregularly on the various nerves, but in special degree on the sciatic. In these cases the pain is extensive, and often severe in the front of the thigh, but the symptoms of descending neuritis are prominent chiefly in the sciatic. Symptoms.— The two nerves suffer with nearly equal frequency, but Gibson found, in his extensive series, that the left was a little the more liable, in the proportion of 48 to 44 per cent. In about 7 per cent. both were affected simultaneously — a striking indication of the smaller relative part played by the general blood-state, compared with poly- neuritis, and the preponderant influence of local excitants. The chief symptom of primary sciatica is pain along the course of the nerve-trunk, often also along that of its branches; pain in tlie area of its distribution is sometimes subsequently developed. The affection may begin suddenly, especially in cases of rheumatic origin, —as suddenly as lumbago. Some movement seems to excite it, but there has usually been slighter rheumatic pain in the neighbour- hood for a day or two, generally about the hip or sacrum. More frequently the onset is gradual; slight pain is felt along the back of the thigh, on movements and in postures that make the nerve tense, or cause pressure upon it. This pain, due to a slight degree of inflammation, has generally existed for some weeks, increasing in degree until a considerable severity is attained, or suddenly becoming intense under the influence of some exposure or over-exertion. At SYMPTOMS. 127 last the patient is easy only when at rest, and when the leg is in a certain posture. Any movement that makes the nerve tense causes pain, and to avoid this the knee, in walking, is kept slightly flexed, and the leg held stiffly so as to avoid stretching the nerve. As the pain on movement increases, spontaneous pain is added, at first chiefly felt in the nerve-trunk, but soon spreading to its branches and distri- bution. It is usually most intense in certain spots — (1) above the hip-joint, near the posterior iliac spine, (2) at the sciatic notch, (3) about the middle of the thigh, (4) behind the knee, (5) below the head of the fibula, (6) behind the external malleolus, (7) on the back of the foot. The pain may radiate over the whole distribution of the nerve, but it is often so distinctly limited to the course of the trunk and branches, that the patient points these out with exactness when he indicates its course. The chief intensity of the pain is usually down the back of the thigh It may be dull or acute, is often burnmg in character, and worse at night. It may seem to dart downwards, starting from the highest point. As the pain on movement increases, the nerve-trunk becomes extremely tender to pressure. Even Defore the tenderness becomes considerable in the thigh, pain may often be produced in the following manner : — Let the patient sit on a chair with the knee at a little more than a right angle, and the body bent forward, so as to lengthen the course of the nerve at tlie hip- and knee-joints. If the finger is then pressed into the popliteal space, so as to make the nerve a little more tense, a pain is felt in the course of the nerve at the back of the thigh or above the sciatic notch, and behind the hip. It is due to the sensitiveness of the nerve to tension, and is a very useful test, especially when the part inflamed is high uj) within the pelvis. It may reveal the affection of the nerve here, by making it more tense, when there is no tenderness to pressure at the back of the thigh. Abnormal sensations other than pain are often felt in the area of distribution of the nerve, — tingling, formication, and the like ; and in severe cases there may be diminished sensibility on the back of the thigh, on the leg, or the foot. The affection of sensibility at the back of the thigh indicates that the disease extends up the nerve, above the sciatic notch, to the origin of the small sciatic, or that this is involved in a simultaneous neuritis. In severe cases the muscles supplied by the nerve become flabby, tender to the touch, and sometimes distinctly weak and wasted. This is chiefly noticeable in the calf muscles, and in the group supplied by the external popliteal nerve. A tendency to cramp in the muscles is often very marked. There may be an alteration in the electrical irritability, usually a sHghl; increase to each form ; it is considerable, and amounts to a distinct degenerative reaction, only in very severe cases. SKght fever and corresponding constitutional symptoms may attend an onset that is acute, when the inflammation is intense. Chronic cases, however, are usually not attended by elevation of temperature. 128 SCIATICA. The duration and severity of tlie affection are extremely rariable. They depend on its intensity, and on tlie amount of rest given to the limb in the early stage, and on the constitutional state of the patient. The inflammation may be trifling in degree, causing pain on move- ment only, which may pass away in the course of a few weeks. On the other hand, the spontaneous pain may be so continuous and intense that sleep can be obtained only by the help of narcotics, and the disease may continue for many months, and even for a year. In most cases that last more than a year there is partial recovery and relapse. Improvement is shown first by the subsidence of spontaneous pain, followed by the slow diminution of the pain on movement, and then of the tenderness of the nerve. The muscular wasting, which occurs in severe cases, may last long after the active stage is over ; fibrillary contractions in the muscles that have been affected may continue for years, and are often accompanied by a strong tendency to cramp, which may be excited by voluntary contraction. Occasionally a secon- dary neuralgia is set up, which may be very enduring, may involve the entire length of the nerve, and may be wide in distribution, ex- tending outside the sciatic area. The disease is prone to relapse, and still more prone to recur after recovery. A second attack may occur in the same or in the other leg, but both legs are scarcely ever affected at the same time. At last, however, the tendency of the sheath to be inflamed seems to become exhausted, and the liabitity to cease. The cases of secondary sciitica depending on disease outside the nerve, compressing or irritating it, differ, in some respects, from the primary form. The early pain is felt less in the nerve-trunk than in its distribution, especially when the nerve suffers first by pressure; interference with the conducting functions is more conspicuous in the early stage. The primary form may be afterwards closely simulated, because secondary inflammation may descend the nerve and induce the same tenderness of the nerve-trunk. The course of the secondary cases is more progressive, but it depends on that of the original disease. Complications of sciatica are rare, but one or two deserve mention. Cutaneous eruptions, usually herpetic in character, have been occa- sionally met with. These may heal slowly, but, in themselves, they are unimportant. Sometimes the epidermis exfoliates ; oedema of the limb occurs in rare cases. These are, however, rather effects of the neuritis than complications, and so also is the muscular wasting that is occasionally pronounced. The trophic changes in the skin are the expression of a peculiarly irritative character of the inflammation. Occasionally the symptoms of inflammation of one sciatic nerve are attended by bilateral symptoms, especially at the onset, such as tingling or pains in the feet and the soles, or some weakness of the flexor muscles of both ankles. These indicate an associated poison ; it may be alcohol causiug its own peculiar bilateral peripheral neuritis, and PATHOLOGY. 129 aiding in the generation of their acute gouty effects on the sciatic. Such a combination may puzzle the observer. A rare complication is a tendency of the mischief to ascend the nerve. Thus symptoms may spread from the region of the sciatic to that of the lumbar plexus ; the pain may spread to the front of the thigh, and the extensors of the knee may become flabby and weak. This is probably due to the passage of an ascending neuritis up the lumbo-sacral cord. In extremely rare cases the morbid pro- cess has apparently reached the spinal cord, and indications of cord disease (e. g. disordered sensibility in the soles) have thus succeeded those of a primary and apparently simple sciatica. There may even be symptoms of lateral sclerosis (excessive knee-jerk, rectus clonus, &c.), such as develop in some cases of arthritis and other conditions of pro- longed pain. The wider distribution of the pain and other symptoms, when a rheumatic inflammation is extensive from the first, may have the aspect of a complication, but often the involvement of the sciatic does not dominate the case, which is then rather one of general crural neuritis, the result of the affection of the fibrous tissue of the floor of the pelvis where numerous nerves arise. The position of some of them determines the frequency with which they suffer specially, but the size of the sciatic nerve-mass necessarily causes its affection to be chiefly conspicuous. That of some of the lowest branches of the lumbar plexus also determines the common seats of the effects of extension upwards. In spreading cases, one effect of extension is of particular import- ince — the paralysis of the bladder that may result from extension to its nerves. The nearer part of the lumbar plexus is often then involved, and pain is felt ia the front and outer part of the thigh, and even in the groin and lower part of the abdomen. The vesical nerves from the pelvic plexuses of the two sides are near together, and the palsy of the bladder is often complete, and of long duration, outlasting, it may be, all other symptoms. Fortunately, it is a very rare complication. Pathology. — The evidence of pathological changes is scanty. Rheumatic inflammation of the nerve is scarcely ever met with in its active stage ; the disease is not one which is even attended by death from other causes, and the morbid changes are a matter of inference. There is, indeed, hardly any organic disease so common as sciatica, of which, in its various degrees, opportunities for pathological observa- tion are so few and so meagre. Signs of inflammation have been found, chiefly conspicuous in the sheath of the nerve, and invading the interstitial tissue in more severe and prolonged cases. They are such as are met with in all forms of perineuritis — swelling and redness, most distinct opposite the middle of the thigh — thickening of the sheath, invading the substance of the nerve. Microscopical changes have been found, similar to those in acute neuritis elsewhere^ in the rare opportunities for observation that have been met with. VOL. I. 9 I'SU SCIATICA. The existence of neuritis in all severe cases admits of no doubt; tlie symptoms — wasting of tlie muscles and anaesthesia — indicate structural damage to the nerve-fibres, and preclude any other explana- tion. There is every gradation between these severe forms and those which are slight, and the symptoms in the latter are identical with those of the earlier stage of the severe cases. The early local tender- ness proves the initial affection of the sheath and fibrous tissue. All cases of definite persistence and prolonged course are inflammatory. Only transient pains coming and going, associated "svith neuralgia else- where, can be regarded as of neuralgic character. These are often the sequel to a true neuritis, or are, not seldom, the manifestation of a tabetic neuralgia, the pain of which may recur during years in a neuralgic form, and even be influenced in its incidence by change in the weather, so as to receive a rheumatic character. The symptoms are explained by the morbid process, and the facts of neuritis in general, already described, apply to this disease in every point. It is primarily a perineuritis ; the pain m the nerve and its tenderness are due to irritation of the sheath-nerves. The pain re- ferred to the distal portions of the nerve is due to the irritation of its conducting fibres by the interstitial inflammation, while their greater damage explains the sensory impairment and muscular wasting. The disease, like other forms of irregular neuritis, is not one essentially of the nervous system. It is a local effect of the con- stitutional malady, gout, or the fibro-rheumatism which results from the inherited diathesis, and each seems to depend on the presence of chemical toxines in the blood, generated in the body by abnormal metabolic processes. Uric acid is probably only one of these, and not the most harmful, or that which has the most special influence. But the nature and origin of these is still one of the most obscure as it is one of the most important problems of pathology, and we must assume that it acts upon tissues disposed to degraded nutrition by the influence of inherited tendency. Diagnosis. — The distinction between a sciatic neuritis and a sciatic neuralgia is sometimes difficult, although less frequently than might be inferred from current accounts of these diseases, in which the history of the neuralgia has been written from the symptoms of the neuritis. If we recognise that all cases of sciatica with persistent tenderness of the nerve are really neuritic, cases of sciatic neuralgia become extremely rare. The two diseases occur usually under different conditions : the subjects of neuralgia have often suffered from neuralgia elsewhere, .and are generally weakly and anaemic. The pain is from the first spontaneous ; it occurs as part of more extensive and severe attacks ; posture has little influence upon it ; movement is not itself painful, although it may excite paroxysms of pain. The pain is referred to the branches and distribution of the nerve rather than to its trunk, or it ■darts up or down the trunk ; and tenderness of the nerve, if it exists, is altogether subordinate to the spontaneous pain. TREATMENT. 131 When the nerve is only one of many localities in which the pain is felt, and the patient is an adult, the possibility of its tabetic nature must be remembered. This is practically certain if the knee-jerks are assuredly absent, but of this fact there must be no question. The " lightning " character of the pain is an important diagnostic feature in such cases ; although the presence of this character has almost pathog-nomonic significance, pain of less acuteness and brevity is often significant. It is an instance in which a certain feature has great significance, but its absence is of relatively small value. Secondary sciatica is usually produced by disease of bone about the hip-joint, or of the joint itself, or by disease in the pelvis. In the former case a careful examination (never to be omitted in any case of sciatica) at once reveals the mischief. When the disease is within the pelvis, and is not primarily connected with the nerves (as the pressure of a growth), the tenderness of the trunk of the nerve is slight in pro- portion to the pain felt in its distribution ; this circumstance should always lead to a careful search for any indication of pelvic mischief. In any case of doubt, or of prolonged course with steady increase in the symptoms, a rectal examination should be made. Sciatic pain occurs in some diseases of the bones of the spine, in lesions of the cauda equina, and occasionally in disease of the spinal cord itself. In these cases we have little or no tenderness of the nerve ; the pain is chiefly peripheral, and very often bilateral. Double true sciatica is so rare that bilateral pain should always suggest disease of the nerve-roots ; but the pain in these cases is generally irregular in its distribution, and considerable in other nerve areas in the leg or neighbourhood of the hip, and is often increased much by movement of the spine. These cases of "secondary sciatica" are of much practical import- ance, because their nature is usually mistaken ; for a long time the patient is thought to be the subject of the ordinary more common form, and is treated accordingly, even when the character of the pain should raise a suspicion of the nature of the case. Prognosis. — The prognosis of sciatica, not secondary to disease outside the nerve, is good as regards ultimate recovery, but is very- uncertain as regards severity and duration. As a general rule, these features are proportioned, but both are influenced by the practicability of adequate rest. Irritating exertion may lengthen the duration of the disease by many months, and indeed relapse may follow each partial recovery for one or two years. Spontaneous pain, and that which is referred to the distribution of the nerves, make the prospect less favourable. Treatment. — The principles of the treatment of sciatica are those of neuritis already described, and only the points of special character need be here repeated. In all crises rest to the limb is important beyond any other measure, and its urgency is proportioned to the acuteness a,nd severity of the symptoms. Many slight cases are converted into 132 SCIATICA. serere ones by unwise exertion. Every posture that induces pain, and all movements which increase that which exists, should be avoided. The same is true of pressure on the nerve by a hard seat, and by strong contraction of the flexors cf the knee. Pain may be thus suddenly brought on in severe degree, and may endure. In more positive treatment the causes of the disease must be remembered, and, among these, the frequency with which it is related to a gouty or rheumatic blood-state. In gouty cases saline purgatives are often of signal service, and are distinctly usefiil in preventing attacks in those who are liable. In the acute stage of a severe attack, hot linseed-meal poultices should be applied along the course of the nerve. Counter-irritation is of great value, and cannot be employed too early. A commencing attack may often be cut short in a few days by rest, and a series of mustard plasters or smaU blisters appHed over the seats of pain, moved as this changes under their influence, chasing it, as it were, from one spot to another, until it disappears. Internally, whenever there is reason to believe that active inflammation exists, mercury should be given — a grain of blue pill twice daily ; nothing else seems distinctly to influence the process. Salicylate of potash or lithia, and nitrous ether, should also be given at the onset — soda salts being avoided. Spontaneous pain can only be relieved by sedatives. Morphia is the surest, but it should only be used for the relief of severe spontaneous pain. Cocaine often proves of great service, if it can be combined with rest, and injected at the actual source of the pain. It should be injected pretty deeply at this place, but not into the nerve. One twelfth of a grain may be first used, increased rapidly to a third or half a grain. It generally relieves, although not in the same degree as morphia, but it seems to have more influence in promoting the subsidence of the inflammation, as described in the account of neuritis, apparently because it has a more distinct influence on the conduction of irritating impulses along the nerves. Morphia, although equally effective elsewhere, may also be injected with advantage over the inflamed part of the nerve, so as to combine the counter- irritation of cutaneous acupuncture with some local as well as general sedative influence. Simple acupuncture along the course of the nerve has been recommended: it gives temporary relief to the sciatic pain, as to any superficial pain, but the cases are verv few in which it has a permanent effect. Sedative or counter- irritant liniments and ointments may also be applied along the course of the nerve ; the most useful are belladonna liniment mixed with an equal part of chloroform liniment, and aconite ointment, rubbed in until distinct tingling is produced. Electricity is chiefly useful in the later stages ; its method of use has been described in the account of the treatment of neuritis. In very obstinate cases, nerve-stretching has done good; sometimes, perhaps, by releasing the nerve from compressing adhesions, but probably more often by effecting an energetic counter- irritation, and enforcing a beneficial rest. It has GENERAL CRURAL NEURITIS. 133 ceased to be tie fasMon it was a few years ago, proof of its limited power. Forced movement of the joints, followed loj rest, has been sometimes employed. In severe cases absolute rest in bed, and, if necessary, the application of a splint to ensure this, has been recom- mended. "Weir Mitchell* has urged the use of a long splint, reaching from the axilla, jointed, so that the hip and knee-joints may be slightly varied in position, and the combination with this of a soft flannel bandage to the limb. The latter should be reapplied twice daily, from the foot to the groin, to lessen the amount of blood in the limb. If further measures are necessary, the application of the Paquelin cautery to the tender points, or of tin splints filled with ice water, is recommended, and after recovery massage with plentiful feeding. To prevent recurrence the causes of gout should be carefully avoided, and any signs of a gouty state lessened by an appropriate regimen. Habitual saline aperients are very important ; the " flush out " clears away bile that would be reabsorbed, and the result is the same as increased secretion from the liver. Slight pain, threatening a recurrence, should be met by more rest, by counter-irritation with sma^ pisms, and the careful avoidance of sudden movements, and indeed ot all exertion that causes or increases pain. If this is considerable, or the nerve is distinctly tender, complete rest for a day or two may obviate the subsequent need for weeks of rest. If there is the sacro- lumbago that often precedes sciatica, the pain produced by sudden movement may often be lessened by a few moments' rubbing. General Crueal TTeiteitis. ■ In rare cases. " rheumatic " inflammation of the fibrous tissue ■covering the lumbar and sacral plexuses is so extensive that many or most of the nerves to the leg are involved, in consequence of the affection of their coverings at their origin. That of the sciatic may preponderate, as already mentioned in the section on Diagnosis, where the general characters of this form are referred to, and its secondary origin by extension, in some cases of primary sciatic neuritis. The cases in which the affection of the fibrous membranes is extensive give rise to such wide-spread symptoms, pain taking the com-se of many nerves and accompanied by the tenderness of descending neui-itis and impairment of movement, often chiefly from the inhibitory influence of the pain it causes, attended by moderate muscular wasting. There is usually slight increase or decrease in the electric irritability in some group of muscles, with increased knee-jerk, very rarely the reaction of degeneration where the nerves have suffered severely, and then the knee-jerk may be lost if these are the extensors of the knee. In cases of general crural neuritis the extent of the symptoms causes them to simulate such as are caused by disease of the spinal cord, * Weir Mitchell, ' International Clinic,' 1891. 134 NEURO-MYOSITIS. and tlie distinction may be one of real difficulty. But it usually suffices to be aware of its occurrence and general characters, especially the moderate degree of the objective symptoms, and the existence of tenderness of sonie nerve-trunks near the pelvis. The diagnosis is also aided by the fact that it occurs chiefly in those who present a gouty or rheumatic disposition, acquired or inherited. The difficulty may be increased by the occasional presence of reflected pain on the opposite side, distinguished, however, by its slighter character, and correspondence in seat to that which is most severe on the side chiefly affected. The course of these cases is often prolonged, and months may pass before improvement commences, especially when the under- lying constitutional state is not recognised, the treatment of which, as in sciatica, is of primary importance. Anterior Crural Neuritis. — Such an affection of the fibrous tissue may be liraited to that related to a single nerve, or some other branch of the sacral or lumbar plexus may be the seat of a neuritis like that which underlies sciatica. The anterior crural, or a branch, suffers most frequently, with resulting symptoms in the front of the thigh, or in the outer part. These are chiefly sensory ; motor symptoms are seldom conspicuous in cases so limited in area. The outer part of the thigh, in the upper two thirds, is a specially frequent seat of pain and occasionally of diminished sensibility. Anaesthesia in this region sometimes develops in a very chronic manner, without pain, as an isolated but curiously enduring symptom, usually stationary when discovered, and apparently the result of a limited neuritis of chronic form. It seems to have no sinister significance, but has little tendency to yield to treatment. NEUEO-MYOSITIS. The term " neuro-myositis " is perhaps the most convenient by which to designate an affection, usually confined to a single Hmb, generally the arm, in which symptoms indicating an interstitial rheumatic inflammation of the lauscles are the leading feature. They become tender, but the especial character is the pain caused by contrac- tion of the fibres, i. e. by the stimulus which, normally, generates afferent impulses. The adjacent fibrous tissue may also suffer, and especially that about the joints, while the condition of the nerve trunks may be such as to give rise to symptoms like those of simple brachial neuritis ; but in such cases the affection of the nerves is subordinate to the peculiar state of the muscles. The affection has thus fairly well-defined features related to the tissue in which the afferent impulses originate, and these are common to all cases, however widely the rheumatic affection may spread, and however severe the NEURO-MYOSITIS. 185 additional symptoms whicli partake of the characteristics of other allied diseases. Hence the suitability of the name " neuro-myositis," in spite of some limitation of meaning which this use implies.* The affection occurs chiefly in patients in the second half of life, and under the same general conditions as brachial neuritis. It is, however, met with mere frequently in young persons, sometimes even in children, especially as a troublesome sequel to rheumatic fever, limited to the structures and muscles of the hand. More often it commences in the neighbourhood of the shoulder, in the deltoid and upper arm muscles, and passes down the arm to become more severe in the hand than at the elbow. Slight changes usually occur in the articulation of the shoulder, but more troublesome arthritic adhesions form in the finger-joints and at the wiist, as is common when mus- cular pain interferes with movements in rheumatic persons. This lasts so long in the intrinsic muscles of the hand, and tissues about the tendons, that the fixation of the joints becomes permanent before there is time for the restoration of the muscles, and some oedema in the acute stage is followed by the characteristic changes in the nutrition of the skin, peehng of the epidermis and wasting of the subcutaneous structures. But the affection of the muscles is the characteristic feature. The symptoms clearly indicate a rheumatic interstitial inflammation, affecting the tissue in which the afferent nerves begin, and the impulses they convey originate, perhaps, in the mysterious "muscle- spindles." In this tissue the impulses, unfelt in health, are generated by tension and compression, and become painful in some conditions, as after cramp. Then, if the muscle is stretched in extension, or the interstitial structures are compressed by muscular contraction, considerable pain is readily produced. Simple muscular rheumatism, transient, such as the common form of lumbago, seems an affection of this interstitial tissue too slight to persist as permanent inflam- mation. The chief feature of the form now under consideration is the production of pain by those forms of stimulation to which the nerve-endings normally respond (see p. 58), compression by voluntary contraction, and the passive tension in the antagonist. Pain is caused also in the structures about the joints, especially in the capsules, when the limit of movement is reached which the state of the various structures permits. Even passive movement induces a sudden contraction of the muscles, i artly reflex, partly voluntary, which causes pain. This pain spreads widely in the mus- * It has indeed been proposed by Senator to use it to designate another disease, the rare acute symmetiical myositis (described further on), whicli is like multiple neuritis in toxic causation, and distal bilateral distribution (' Deut. med. Wochen- schr.,' 1893). The term has not, however, come into use for this affection, and seems not needed for it. " Acute myositis " or "polymyositis," the names employed in Germany, are sufficiently adequate to leave to its jiPL'seut application the term " iRuro-myositis." 136 NEURO-MYOSITIS. cles, as tliose adjacent contract to stop tlie movement to which the pain seems due, and it is produced with readiness in the morbid state. Hence arises the characteristic feature. Muscular contraction, the great cause of pain, results from any movement, active or passive, and the patient acquires the conviction that no passive movement of the limb is possible without the production of pain in the muscles. Such pain does actually occur whenever an attempt is made to move the joints, as the shoulder and elbow, even in slight degree, or the wrist-joint, if with any suddenness. It is first and most felt not in the neighbourhood of the joints, but in the muscles. Afterwards some may be felt in the structures about the joint. On close and careful observation it will be found that the pain is related much more to the expectation of passive movement than to that which takes place. Before any movement is produced, the muscles contract in order to control and restrict the source of expected suffering. The pain coincides with this contraction, which is unconsciously vohtional and reflex, rather than really voluntary. But with the help of some patience and perseverance it is possible to get the limb quite passive, resting without effort in the observer's hands, and to make gentle slow passive movement of the joints without the occurrence of this inhibitory contraction of the muscles. The patient is often astonished at the painless movement of joints when he thought great suffering would result from the least displacement of the parts. But if then a more sudden movement is made, and the alarm and perhaps slight pain cause sudden spasmodic muscular contraction, the pain felt in the muscles is great. There is usually some tenderness on sudden compression of the muscular substance, and this may be considerable and produced with some readiness, but often the sensibility to pressure is inconspicuous. We know, from the state left by common cramp, how easily pain is produced in the muscle by contraction; when this is sudden and considerable the pain may be shared by the nerves ; as already stated, those of the brachial plexus above the clavicle and in the axilla, present the same tenderness as is met with in simple brachial neuritis, although in slight and subordinate degree, manifestly from the inflammation of their sheaths. Other structures suffer, as already stated. The res\ilt is a considerable amount of fixa- tion of the limb from the pain which is produced by movement ; this has more than one source, and it may be difiicult at first to discern that from which the chief suffering proceeds. The arthritic changes within the joints produce adhesions which, with the alteration in the capsule, fix the joint in an abnormal posture, generally that which falls short of complete extension. The contraction of the muscles to inhibit movement tends to be more and more persistent and continuous, and this state of rigidity is prone to cause some shortening of their stractures ; nutritional change fixing the functional states assists in producing the slight deformity and fixed posture of the joints that are frequently observed. ^'EUKO-MYOSITIS. 137 The malady is commonly of very prolonged duration, developing insidiously even after recovery from an initial, more acute attack of local rheumatism, especially wlien slight persistent pain on move- ment is maintained by the neglect of needed rest. The affection is usually unsymmetrical, affecting one side only, after the fashion of these rheumatic affections of the fibrous tissues, of sciatica, or of brachial neuritis. Nevertlieless, in moderate typical form, tlie manner in which it presents itself as an affection of the interstitial tissue of the muscles and their nerves justifies the view which is expressed in the designation given to it ; and the peculiar implication of the afferent muscle-nerves, in consequence of its interstitial localisation in the muscles, justifies its inclusion among the maladies here described. This is further warranted by the condition which commonly results. The duration of the affection and the changes which ensue in the sub- stance of the muscles and the tissue about the joints, and the fixation of these during the time that elapses before the cessation of pain permits freedom of movement, by that time mechanically hindered, bring the cases into the class of residual consequences of nerve lesions. The resulting interference with use of the part is greater than is proportionate to the amount of rheumatic iaflammation, being espe- cially great when much sensitiveness has proceeded from the long- continued pain, and fear of its induction outlasts the danger and exceeds it in degree. Some chronic neuralgic pain is apt to remain, due in part to the predisposition to neuralgia which most patients of this class possess. Another cuiious sequel hinders the return of mobility in these cases. Passive movement is difficult out of proportion to any pain produced, although this results if the attempt is persevered in and its strength increased. The common effect is a peculiar rigidity of the limb, such as at first suggests firm adhesions at the joints — an impression that may be easily retained if the examination is hasty. Its nature is rendered clear by sufficient patience and close observation; passive movements must be attempted with the utmost gentleness and slow- ness, and the attention of the patient turned to some other part during their course, while the observation of the examiner remains fixed. The same care is necessary in local therapeutic measures if these are to be successful. Gentle upward rubbing to the muscles should be afterwards combined with slow passive movement, at first scarcely appreciable in degree, and continued with the endeavour to keep behind the production of the muscular spasm. This will often permit good to be effected by local applications of heat, dry or moist, liniments, &c. The internal treatment needed is such as is suitable for the gouty and rheumatic constitutional state, with tonics whore these are indicated, and is of the same general character as that recommended for brachial neuritis. Gout and Rheumatism in the Causation of Neuritis. — It may seem to many readers that the range of influence of these constitutional states has been pushed too 138 MULTIPLE NEURITIS. far in the preceding account of the affections, which are primarily of fibrous tissue, and only of the nervous system by reason of proximity. The difficulty may be increased by the number of patients who present no adequate personnl or hereditary evidence of such causal disease or tendency. Bat it should be noted that the influence of gout, including ancestral gout, is a subject on which the young practi- tioner starts with a high degree of scepticism regarding the teaching of his seniors. But year by year liis doubts b-rome fewer, as they are rubUed away, or removed more sharply, by contact with act. The negative influence of the cases in which the cause cannot be traced, or only in plight degree, should be carefully weighed before the result is placed in the scale. MULTIPLE NEURITIS. The term " multiple neuritis," or " polyneuritis," is applied to the condition in which many nerves are inflamed simultaneously or in rapid succession. This multiplicity is combined with bilateral sym- metry, alike in its seat and in the special character of the symptoms. These constitute its most obtrusire features. If only a few nerves are involved, the symmetry becomes a more salient feature than the multipHcity. The symmetry is not only characteristic, it is of profound significance, because commonly combined with a third feature, the fact that the affection is most intense at the extremities of the nerves, and lessens progressively towards the centre. This " peripheral " symmetry can only be due to a cause circulating in the blood or inherent in the vitality of the nerves. The former is the common mechanism, but some influence of the latter is indicated by this seat, — farthest from the central source of nutritional energy, where the resistance to morbid influences is least. On account of the seat the disease has also been termed "peripheral neuritis," a name that is accurate but somewhat confusing, because it has been used to distinguish all affections of nerve-trunks from central diseases causing similar symptoms, especially in the case of the cranial nerves. It should not be employed in this sense. The name " polyneuritis " has also come into extensive use, and perhaps will more readily secure association with another important characteristic, though practically identical with " multiple neuritis." The microscope shows that the changes are almost, confined to the proper tissue of the nerve-fibre, and do not implicate the sheath or interstitial tissue, as a rule, even when acute. This, indeed, we might expect from the special limitation in the function deranged. But it affords a contrast to the forms of neuritis previously described. These may be multiple, and even, very rarely, symmetrical, as when both sciatic nerves are inflamed. But the symmetry is rough, and it does not extend to precision in the function disturbed, and soon ceases to be distinct. It is this affecticii of the true nerve tissue, and its results, PATHOLOGY. 139 which marks the symmetry of the form under consideration, and is absent in the occasional multiplicity of the inflammation met with usually in single nerves. This character, of absolute ultimate import- ance, is more likely to become attached to " polyneuritis." A name is needed which embodies also the idea of symmetry. The discovery that certain combinations of symptoms, formerly thought to depend on disease of the spinal cord, are really due to disease of the peripheral nerves, is one of the most important steps in the recent advance of pathology. It has profoundly modified many of our conceptions, and has opened a new field in pathology, the culti- vation of which has but begun. The occurrence of multiple neuritis was first demonstrated by Dumenil, of Eouen (1864), although the leprous form (which differs in important pomts) had been previously described by Yirchow. Todd also deserves credit for a correct and clear perception of an affection of the nerves as the cause of lead palsy in 1854.* Graves, indeed, long ago suspected that many cases of paralysis were due to disease of the nerves, but he based his opinion on the normal aspect of the spinal cord ; and in most of the cases he describes it is probable that modern methods of examination would have revealed disease. Symptoms so peculiar had been noted from time to time ; first, perhaps (1822), by Dr J. Jackson, of Boston, U.S.A. They were fidly described by Duchenne in 1858. Even Dumenil's observations attracted little notice, and it was not until fresh facts were brought forward by Joffroy (1879), Leyden (1880), and Grainger Stewart (1881), that attention was generally directed to the subject. Since that time a very large number of observations have been published, and the wide relations of the morbid process are now perceived. Among these one stands out conspicuously. The forms of multiple neuritis which present local and functional symmetry and are of parenchymatous nature must be ascribed to a blood- state having equal access to all parts, but a special action on those that suffer, or do so most readily, owing to a peculiar and constant disposition inherent in those structures thus to be affected. The cause of this affection is the presence in the blood of some virus, and the sahent fact is that the toxic agent is usually a poison of chemical nature, a metal, or an organic chemical material often resulting from the growth of organisms in or out of the body, sometimes apparently from disordered processes of digestion or excretion, or deranged metabolism within the body, varied in seat and nature. To such a poison some nerve-fibres are specially susceptible, just as they are to curara, or to * The first ascription of a form of paralysis to this lesion was by Dr. Todd, in the case of lead palsy. " I believe that the muscles and nerves are early affected, and that at a later period the nerve-centres become implicated. The nervous system ia thus first affected at its ppriphery, in the nerves, and, the poisoning influence con- tinuing, the contamination gradually advances towards the centre " (* Clin. Lect./ 1854, p. 9). l40 MULTIPLE NEURITIS. strycliuia, or to atropia. It is a manifestation equally of a peculiarity in the acting virus and in the structures acted on. The virus is clearly one, in most cases, of chemical composition ; and it may be so also with the chanL,^es in structiires acted on — under the influence of life incon- ceivably minute but constant, and determining the changes which attend functional action, and modifying this when altered. Isolated neuritis may be caused in part by a constitutional or blood state, but is not due to this alone. An exciting cause is in opera- tion, which acts locally and determines the position of the affection. Hence, as we have seen, such neuritis is rarely multiple, and still more rarely even roughly symmetrical, while these features are ex- plained by the irregular affection of the connective tissue instead of an impaired nutrition of the proper neural structures. This distribution holds good to a remarkable extent and degree. When the symmetrical polyneuritis is severe, even to death, and the nerve- structure has practically disappeared, by destructive change, from the distal parts of certain nerves, the interstitial tissue and sheath show only a trifling increase in their nuclei. "We find morbid appear- ances in them chiefly in extremely acute cases, when the vessels are dilated in the sheath or interstices ; the changes due to oedema are seen ; white corpuscles are aggregated outside the minute vessels, and even extravasations of blood occur in addition to rapid destruc- tion of the fibres proper. So, on the other hand, a very intense interstitial neuritis may involve the nerve- fibres proper. There are also cases in which the causes of the two forms are com- bined. Alcoholism, for instance, the most common toxic cause, may be due to influences that have also produced gout, and then isolated gouty perineuritis may accompany polyneuritis of parenchymatous nature and symmetrical distribution. In one instance of this a peri- neuritis of one external popliteal nerve, causing palsy of the flexors of one ankle-joint, limited to that side, was followed, after some months (its cause continuing), by a gradual loss of power in these muscles on both sides, with the reaction of degeneration in the muscles, loss of the knee-jerk, pains, and sensory changes. Exposure to cold, again, may cause a " rheumatic " perineuritis, either of a single nerve or of a few nerves irregularly distributed, and it may also produce a blood- state allied to that of acute rheumatism, and a symmetrical parenchymatous polyneuritis sometimes most severe. The effective poison may be due to organisms in the blood, especially those of specific nature that cause a definite disease, as diphtheria or smallpox. They may be of less specific character, as those which enter by contaminated wounds, impure puerperal processes, and the like, the effects of which may be severe out of all proportion to their apparent cause, from a special susceptibility to certain agents. We have reason to ascribe the neuritis to chemical agents produced by the organisms, but they seem themselves capable, in many cases, of setting up neuritis also, interstitial in seat and moi'e irregular in 'dicLribution, ETIOLOGY. 141 besides giving rise to tlie product, perhaps a chemical snbstance, com- parable to alcohol, capable of causing a parenchymatous neuritis. The two foiins may then be conjoined in a puzzling manner, varying in relative amount in different cases. It is probably thus that the forms of diffuse or total neuritis are produced, occasionally met with in diphtheritic paralysis. We have here a field still to be investigated. Not less important and mysterious are the distinct indications that symmetrical neuritis results from toxines developed within the body from the effects of other chronic diseases. Diabetes is one of these, but the poisonous agent is not the sugar in the blood, for the palsy occurs when there is but a very small amount in the urine. One de- ranged chemical process involves others, which ^ary in different persons, and minute chemical variations may determine profound differences in effect, ranging from the innocuous to the toxic. In advanced organic kidney disease also signs of polyneuritis may appear — pains in the legs, loss of the knee-jerk, paralysis of the muscles, tingling of the skin, anaesthesia. Poisons capable of producing the condition, but of unknown nature, seem sometimes to be taken in from the outside, although we know not how, for cases of characteristic features occur when the most exhaustive search fails to discover a known cause. Lastly, symptoms of this state, moderate in degree — weakness at the ankle, loss of the knee-jerk, subjective sensations, or definitely defective sensibility below the knees,— sometimes come on gradually in the old, without other cause than the influence of advancing years. The symptoms seem not to be progressive, and become less noticed when they are slight, although they are sometimes maintained by attention in a troublesome degree. They are apparently due to a degenerative tendency due to age, and are signs of a senile form. We must assume that the nerves which suffer most in this disease possess less power than others of resisting morbid agencies, and that their capacity for vital endurance varies in different individuals, to under- stand the occurrence of the malady in those who suffer, and the greater readiness with which it is caused in some by a small quantity of the poison. Indeed, we are confronted at the outset by a fact which involves such a difference inherent in the two sexes. The most common cause, alcohol, gives rise to polyneuritis far more frequently in women than in men. Half a dozen cases will be met with in females before one is seen in a man. An excessive degree of such a disposi- tion to degenerate would necessarily involve an earlier manifestation of the imperfect nutrition which is the normal termination of life. The discernment of this symmetrical derangement of function, of its dependence on the nerves, and the action on them of morbid agents conveyed by the blood, has enlarged our pathological concep- tion by revealing the natui-e of cases previously misconceived, because absolutely not common, and differing too widely in those features that would be put together for their nature to be readily recognised. Indeed, their recognition is probably one of the results of the per- 142 MULTIPLE NEURITIS. ception of how much is meant by the disappearance of the knee-jerk, and the need to observe minutely and compare carefully all cases in which it disappears. This was at least one cause for the appreciation of the significance of the isolated palsy of the flexors of the ankle coinciding Avith such loss as it was found to do, and the more careful study of such eases to which the observation led. But the discovery of the relation of the affection of the nerves to alcohol, which swiftly followed the perception of its peculiar features and the character of their cause, has had effects of even greater import- ance, and an influence on our discernment still far from exhausted. Alcohol is a purely chemical agent. Yarious metallic poisons, acting in minute amount and slowly, were also found to have similar effects, while in other cases the toxines seemed to be also organic chemical substances. This was also supplemented by the discovery that de- rangement of the nervous system such as occurs in tetanus was due to substances of similar nature, resembling strychnia in effect (a vegetable alkaloid), and yet generated by organisms in the system; that the cause of diphtheritic palsy was also a chemical substance, a modified albuminose; and that a similar agency is the cause of the polyneuritis which may follow other acute specific diseases. A wide, unstudied field of chemical pathology has thus been opened, on which multi]3le neuritis will find a place, and clearly included therein are the forms which result from disordered processes within the body in the subjects of gout, exposure to cold, and the like. Chemical change in the nerve- tissue attends all its functions, and by their activity the renewal of elements is increased. Its character depends on the composition of the j)lasma bathing them, and containing the molecules to replace those broken up in function. A slight difference in the constitution of the replacing molecules seems merely to derange the process at first, and a trifling alteration in function is the only result, such as subjective tingling when the sensory nerves suffer chiefly, or lessened perception of the most gentle stimuli. The per- sistence of the process leads to graver change in molecalar composi- tion and more serious effects, and at last the change amounts to an alteration which may abolish function and be visible under the microscope. Such, for example, is the effect of arsenic ; typical polyneuritis results from the constant presence of a definite quantity in the blood. Arsenic has chemical correspondences with phosphorus, as well as differences, which enable us to understand its assimilation by the nerves, and also the gradual changes that result, molecular at first, but at last structural. The affinity for certain parts of the nervous system presented by different substances enable us also to understand that acute arsenical poisoning may be followed by a similar chronic neuritis of bilateral and peripheral distribution, and both motor and sensory symptoms, while very chronic poisoning causes more various, effects, apparently determined by dose and the combinations which the state of the system causes it to form, and in ETIOLOGY. 143 which it is presented to the nerves. The specialisation of the sensory symptoms is remarkable in its variations from all causes ; one form of sensation may alone be disturbed. Always, however, the form is the same, and the seat is the same on each side ; and this feature, whether the disturbance is trifling or grave, should arouse a suspicion that we have to do with the action on the nerves of a toxic agent in the blood. The importance of this indication cannot be insisted on too often or too strongly. It will often save from serious error, from loss of precious time, and the patient from much suifering and prolonged disability. In both acute and chronic forms the influence of the toxic agent may be exerted on the central organs as well as on the peripheral nerves, not only so as to give rise to more or less diffuse inflammation, but limited degeneration of tracts of fibres, as of the posterior columns or the pyramidal tracts. The frequent relation of the former to a toxine is well known, and degeneration of the lateral tracts is known some- times to begin at the extremities of the fibres in a way analogous to that of the peripheral nerves. It is not, therefore, surprising to find central symptoms combined with those of neuritis in various forms, and the resulting effects may present characters of a puzzhng aspect. Such wider distribution must be ascribed to the predisposition of the subject and the character of the active agent. It is indeed surprising that the effects of this one, so frequently limited as they seem to be, and the common restriction of their incidence, are significant of a definite uniform difference in the chemical relations of the nerve- structures, no doubt with an absolute relation to function imder normal conditions as well as to disease. Indeed, the physiological importance of the facts of toxic neuritis are most distinct. They sug- gest that chemical processes have a larger share in determining those of vital function than has been thought, and that their range may be found more extensive and important than was previously suspected. An important question has been raised by the discovery that the central structures often sirffer in cases of peripheral polyneuritis, and that some toxic agents seem to act also on the nerve-cell, the central element of the neuron, as well as on the peripheral structures. But the facts are still too scanty to be of use, and will be referred to again in the section on pathology. It is to the pathology of the disease that we must look for its effective subdivision, but our knowledge of the subject is still imper- fect. The causes of polyneuritis, numerous and various as they are, stUl furnish the best groimd for a practical classification of the forms of the disease such as will assist us in recognising them and in treating them. Symmetrical regularity means a blood- state acting alone ; irregular multiplicity generally means a constitutional state combined with local determining causes. When very few nerves are affected irregularly, the general influence sinks to the level of a predisposition, and this is not always to be recognised when a single nerve is affected. 144 MULTIPLE NEURITIS. The acuteness or slowness of the onset has also been made a ground of distinction, but the symptoms vary much in aspect and grouping according to their intensity. The more chronic the process the more perfect is the limitation of the process and of its effects on function. In the most chronic form the process in the nerve-elements resembles a pure degeneration, and hence has been termed " degenerative neuritis." From most causes we meet with cases both acute and chronic, according to the intensity of the toxic agent. No arrangement can be free from anomalies until we know more of the causes and of the mechanism by which the varieties are produced ; but provisionally, therefore, that we may survey their relationship, the cases may be placed in the following groups. It will be instructive to survey them first generally ; some wiD. need afterwards more special consideration. I. Toxic : due to the presence in the blood of a known poison, a substance commonly so described ; of such the simplest is — (a) Metallic : lead, silver, &c. (6) Non-metallic, as alcohol — the most frequent cause. Other or- ganic substances, formed outside the body, comparatively simple and well known, act in a similar manner. II Toxemic: due to some virus in the blood, the precise nature of which is unknown, but which is apparently a chemical substance formed within the body. It may be — (a) Pathogenetic, the consequence of a specific disease, probably due to the growth within the body of the organisms of the disease, as poisons causing symptoms of another class are due to the organisms of tetanus. Hence the polyneuritis which may succeed the acute specific fevers. A poison having similar effects results from the organisms of septicsemia in its varied forms, traumatic and other, causing most of the cases of puer- peral neuritis. (6) Metabolic. — A derangement of the chemical processes of the body may give rise to a toxine capable of acting on the nerves. It may be the only product of the derangement that manifests its presence by symptoms, but other abnormal substances ai^e formed which can be readily detected, or give rise to other obtrusive symptoms. Thus peripheral neuritis occurs in diabetes, not from the excess of sugar in the blood, but from some other chemical substance the nature of which is not yet known. We cannot have a disorder of the chemical pro- cesses that causes an excess of one substance without other materials being produced abnormal in their nature or in their amount. There may be known the characteristics of some malady, of which the neuritis is an apparent consequence; or they may be inconspicuous, causing no distinct effects, and the- neuritis develops as the only consequence of the causal derange- ment. These forms may be termed secondary and primary metabolic neuritis, according as other abnormal products mani- fest their presence or are latent, but there is evidently na essential difference between the two classes. etioloPtT. 145 (e) Rhetimatic. — An important variety of this class is that in which a toxine, seemingly of corresponding nature, results from an external influence, such as exposure to cold.* Rheumatic poly- nenritis is a special form, and yet seems to be a metabolic form acutely excited by a process the occurrence of which we fan eee, but cannot understand. It varies much in its intensity, and in the severity and character of the attendant catarrhal or rheumatic symptoms. They may amount to those of aotual accompanying disease, which may assume predominant inten- sity and bear the aspect of a primary affection to which tlie neuritis seems to be secondary, and a consequence rather than a mere concomitant. But its cause is evidently the presence of an agent in the hlood capable of deranging -acutely the nutrition of the nerves in a manner more or less grave and endui'ing. The morbid agent thus generated must be pro- duced by a disordered action occurring under the influence of the exposure, but in consequence of a pre-existing state of the system, which we can best conceive as the presence in it cf some morbid state, most probably of the nature of a chemical material, abnormal in character, although perhaps differing but little from those that are normally present. It may be more closely allied to such products, although we con- ceive it most readily as analogous to a simple poison. (cl) Septicsemic. — From such cases we pass to others in which the cause seems to be more special in nature, and in which the resulting disorder of .the peripheral nerves is part of the general disturbance of septicaemia. Septicsemic polyneuritis constitutes an important variety, frequent and often most grave. Its causes are numerous, but present two important variations in nature; the cause may be an injury or operation, or it may be of entirely internal nature. An infective process is the source of an organismal mechanism in many cases of this class. To it belong most, perhaps all instances of puer- peral polyneuritis, an important group, which vary in nature, however, so as to make their precise classification very difficult. They present the common symptoms in characteristic and usually in acute form, but these may begin before or after delivery in association with other symptoms of blood-poisoning although they predominate in the cases that can properly be placed in this category. But variations in course are some- times conspicuous, and cases are seen which present no evidence of distinct causation. Without doubt, however, the majority are due to some form of septicsemic process, and this is true when other signs of it are inconspicuous. Puerperal poly- neuritis is septicsemic as an almost invariable rule. Rare cases are met with, however, in which the symptoms of neuritis develop insidiously, and it may be some time before delivery, in a manner that increases their mystery, while this is further augmented by the termination of these cases in recovery. * See Ross and Judson Bur)''s * Treatise on Peripheral Neuritis.' VOL. I. 10 14fi MULTIPLE NEURITIS. £11. Organismal : of similar character, indeed, are the cases of the disorders that eoTisist in an inflammation of the peripheral nerves, although its cause sfeiiis to he the product of the growth of organisms outside or inside the system. This view is the best we can take of the pathology of such a disease as beri-beri. Even in the case of leprosy, in which there is proof of the presence of organisms as the material agents of the affection, we liave also strong reason to regard the symptoms as largely the result of the influence on the nerve-structures of a chemical agent or agents which are produced by these in their growth. The indirect evidence of the chemical nature of the toxine which acts on the nerve- fibres, and of its organismal source, becomes very strong when the known facts are compared with the proofs we have that such an agent, so produced, is that which gives rise to the symptoms of tetanus by setting up a process of local inflammation, and note that in each instance there is a selective action upon certain structures. IV. Idiopathic roLTNECEiTis, we may term the variety in which no ex- ternal influence acts on the nerve-fibres; their nutrition fails spon- taneously. We have this condition best marked in the important variety in which the symptoms of sensory neuritis come on in late life, in consequence of an imperfection in the endurance of the nutrition of the nerve-fibres. This seems to depend upon a general constitutional imperfection which manifests itself in this particular direction for some reason, the nature and precise cause of which we cannot discern. In other cases we may not have the same special eifect. It is manifested by the sensory moie than by the motor nerves, and chiefly as irritative disturbance of fumtion. We do not usually meet with this idiopathic degeneration except as a senile condition. It is true that it may occur as a condition that is not infrequent although we fail to recognise it, and we must regard some degree of disposition as underlying the occurrence of the morbid state in the majority of instances in which it occurs. Yet the fact that some adequate causal influence is to be traced so frequently as facts show it to be, reduces to small limits any disposition to an idiopathic failure of nutrition such as has been supposed to constitute the morbid state in this form, and makes it improbable that it plays any considerable part in the general production of the symptom. Some of tliese causal varieties need more detailed consideration. The simple toxic forms, of wliicli that due to alcohol is the most characteristic, present the most typical manifestation of the disorder, and afford the ground for its description. We must separate from these cases of symmetrical bilateral neuritis those in which there is an irregular affection of many nerves. Syphilitic neuritis is an affection of single nerves, but several may ■chance to suffer in the same limb. It is a result of the direct action of the organisms on the adventitial tissues. True acute multiple neuritis has been thought to be directly syphilitic in some cases. It would be due to an early secondary toxine produced by the organisms. The evidence of it is inconclusive. A late polyneuritis must be regarded as the lesion of tabes, and this is sometimes met with in an acute form. ETIOLOGr. 147 Buggesting tliat a toxine may be produced at an early stage of the disease, capa.ble of acting on the nerves and causing polyneuritis. The subject is considered in the section on Locomotor Ataxy, but it is important to mention it here, because this disease presents an example of central and peripheral lesions due to the same cause, and because an affection of the sensory nerves almost identical in dis- tribution and nature, and giving rise to similar effects, is sometimes the consequence of alcohol, and occasionally also of other agents, as arsenic* Tubercular polyneuritis is a form regarding which we have still much to learn. It has occasionally developed in the course of phthisis, and has been found to be of the purely parenchymatous or degene- rative variety. Severe cases, with characteristic motor and sensory symptoms, in which other causes, such as alcohol, can be excluded, are rare, but their occurrence is well established,t and they seem to justify the conclusion that the tubercle bacillus is capable of producing a poison having a specific action on the nerves — a mechanism also indi- cated by the fact that the bacilli themselves cannot be found in the affected structures. It is said that similar slighter neuritis is frequently to be foimd after death in cases of phthisis, and probably produces symptoms that are overlooked in the general prostration of the later stages of the disease. Some severe cases recorded as tubercular are, however, not free from the suspicion that alcohol was in part or wholly the cause of the neuritis. There is, moreover, another relation between multiple neuritis and phthisis ; the latter often develops in the course of alcoholic neuritis, and is a frequent cause of death. Qout gives rise to interstitial neuritis and perineuritis, usually isolated, but sometimes multiple and then irregular in distribution. Yet chronic alcoholism occasionally coincides with the gouty state, and may cause a combination of the symmetrical toxic form of typical character, and an isolated neuritis, such as inflammation of the sciatic nerve — a combination which may puzzle unless this origin of it ia recognised. Most Acute Specific Diseases have been followed by neuritis, some more frequently than others, especially diphtheria, variola, measles, typhus and typhoid fevers ; and influenza has had this sequel with notable frequency during the epidemic of the last five years. The interval that usually elapses between the acute disease and the neuritis gives strong support to the pathology of the disease above described. The occurrence of the neuritis does not seem to be related to the severity of the primary disease, but rather to some peculiarity in the special organisms, such as so often determines peculiar features in an * Durdufi ('Neur. Cent.,* 1893, p. 632) directs attention to a fact, especially insisted upon by Leyden, Gowers, and others, that gonorrhoea may give rise to morbid conditions of the nervoas syatem, and mentions especially neuritis and myelitis. t See Oppenheim, * Zeitschr. f . klin. Med.,' 1886, p. 230. 148 MULTIPLE NEURITIS. epidemic. This feature is conspicuous in all the acute specific diseases. In one case, which developed six weeks after varioloid, with pains in the limbs, atrophy of the arms and legs, &c., the purely neuritic nature of the morbid process was ascertained six months later, when the patient died from pneumonia. But the mechanism is apparently more complete in some maladies. In diphtheria a poison is produced which has a more extensive action on the nerve-structures. This is described in more detail in the second volume. In this disease, moreover, the acute stage is attended by an acute inflammation of all the elements of the nerve- structures, and not merely of the functional parts — a more intense morbid agent being apparently active. Malarial neuritis seems to occupy a position intermediate between the secondary and primary forms, since it sometimes follows malarial fever, and sometimes deve- lops without previous fever in those who have been exposed to the influence of malaria. We have much still to learn regarding the pathology of these forms. Septicsemic polyneuritis is a rare variety, but one of the most formidable in many cases, the nerves to vital organs suffering with relative frequency and severity. The most severe cases have been traumatic, the result of organisms introduced from without into some wound, or of some injury or local inflammation capable of giving rise to blood-poisoning. In some such cases the disease has been unaccompanied by the usual symptoms of septic blood-states, but has followed its cause at an interval that suggests, taken with other analogous facts, that it is due to some virus produced pro- bably by septic organisms of a special character. For instance, a man, thirteen days after a stab-wound beneath the clavicle, which healed well, had an attack of parotitis with facial palsy. On the fortieth day there developed paralysis of tongue, vocal cords, and limbs, and on the sixth day after the onset of these symptoms he died from respiratory palsy. Extensive peripheral neuritis was the only nerve lesion.* In a less severe case recorded by Barrsf the symptoms commenced three weeks after a neglected wound of the hand, which produced inflammation of the lymphatics, extending up the arm to the axilla. The symptoms of neuritis began in the injured limb, and invaded successively the other extremities, causing characteristic weak- ness in the lower limbs, with loss of the knee-jerk. He slowly recovered. It is possible that some cases of this class result from unsuspected foci of inflammation within the body, in which pus becomes pent up and causes the blood- state. • In cases with a possible internal source of blood-poisoning, poly- neuritis may develop as an apparently primary disease if the source of the septicaemia has been undiscovered. The nature of such cases is often mysterious. They are not separable from those due to deranged metaboHsm, or to some toxine arising by a different mechanism. • Roth, ' Corr.-Bl. f. Schw. Acrzte,' 1883, No. 13. t 'Amer. Jnurn. Med. Science,' Feb., 1889. ETIOLOGY. 149 Other primary cases occur, moreover, in whidi tHere is no cause for septicaemia, and yet of sucli severity as to suggest a poison coming from a powerful external source. The only explanation we can give of these is that they are probably due to a virus received from without, the precise nature of which is unknown, and that there are sources of such toxines of which we are still ignorant. Some cases have been met with in which the symptoms of multiple neuritis, perfectly charac- teristic, came on without any discoverable cause, and ran a course in most cases mild, and ending in recovery ; in one or two others severe, and ending in death. Some cases of what is popularly termed " blood- poisoning" are probably of this nature. A condition also occurs during the puerperium, and is probably the result of some accidental septicaemic process. The type is one of severe polyneuritis.* A similar condition has also been describedf as occurring during preg- nancy, the symptoms all disappearing after delivery. If certain drain poisons, probably organismal, are capable of giving rise to a disease, diphtheria, of which multiple neuritis is often part, there is no im- probability in some forms of virus, of similar character and analogous source, having such neuritis for their chief effect. In this connection it is instructive to note that an epidemic is on record in which paralysis preceded the throat affection (see Diph- theritic Paralysis, Yol. II). As an instance of this primary form may be mentioned the case of a medical practitioner who was attacked with obstinate vomiting and diarrhoea succeeded by constipation, for which no cause could be discovered, quickly followed by " numbness " in the hands and feet, and a difficulty in using them. When I saw him, a fortniglit later, there was loss of tactile sensibility, limited to the palms and soles, weakness of the legs, and no knee-jerk. The weakness rapidly increased and extended, and at the end of five weeks from the onset he died. Such a case presents all the features of the toxic form. J The Bheumatic form embraces aU the cases of polyneuritis that are due to exposure to cold. Rheiimatic fever, due to a similar exposure to cold, must depend on a morbid blood- state, produced in some way by the disturbing influence of the chill on the metabolic processes within the body. The poison thus generated must vary much in its * Mobius, • Munch, med. Woclienschr.,* 1892, Bd. xlv; Bernhardt, ' Deut~c-h. med Wochenschr.,* 1894, Bd. 1; Eulenburg, ' Deutsch. med. Wocheiischr.,' 1895, Bd. viii, ix ; Sottas and Sottas, • Gaz. des Hop.,' 1892; Turney, 'St. Thomas's Hosp. Reports,' vol. xxv, 1898, who describes three varieties: (1) generalised neuritis, (2) localised neuritis aflecting (a) upper, (J) lower limbs, and (3) neuritis affecting a single nerve without any ascertain ;ible local cause. t Stiefel, 'Neur. Cent.,' 1893, 352. J It should be mentioned tliat other circumstances excited a suspicion of inten- tional chronic poisoning. This fact does not lessen the suggestiveness of the case. Multiple neuritis must henceforth constitute an element in many questions of medical jurisprudence. Its discovery might give greater weight to indications of some forms of poisoning. ■150 MULTIPLE NEURITIS. precise nature to cause tlie great variations in tlie acute lesions wLich follow (see Chorea, Yol. II). Hence it is not surprising that the effect of the exposure should, in some persons, be such as to cause a blood-state capable of producing multiple neu:;;tis, symmetrical and parenchymatous. In a case recorded by Putnam, fatal in seven days from paralysis of the respiratory muscles, following directly exposure to cold, there was swelling of the spleen such as is met with in typhoid and other acute toxsemic states. Two cases of fatal septic polyneuritis accompanied by endocarditis are recorded.* We do not know to what these variations are due. In some there has been a previous exposure to chronic alcoholism sufficient to explain the extreme degree of the resulting process. The causes of the differences in the results are, however, still involved in mystery. From this, as from other causes, but perhaps with greater frequency, the blood-state is apt to give rise to more irregTilar central inflammation, and the two may coincide. The connective tissue of nerves is, moreover, of the same natui'e as that on which the rheumatic poison exerts its special influence, and the modes of onset of sciatica have shown us that the rheumatic process may pass from the fasciae to the nerve-sheaths. A considera- tion of the facts makes it probable that cold may cause (1) an isolated adventitial neuritis ; (2) a multiple neuritis of the same character, irregular in distribution, probably by the agency of a blood- poison related to that which causes muscular rheumatism and the affection of the fibrous tissues of the joints in rheumatic fever ; (3) a symmetrical parenchymatous polyneuritis due probably to a special blood-state of greater specificity than that which produces the adventitial form, and perhaps allied to that which gives rise to pneumonia and to cerebro-spinal meningitis. Pneumonia, at least, may be combined with multiple neuritis as a result of the same exposure. The diabetic form presents many varieties, and our knowledge of it has been already referred to so far as its imperfect character permits. It is not related to the amount of sugar in the urine — in many of the sufferers this has been small (in one, indeed, as low as one hcJf per cent.) ; nor is it readily influenced by a dietetic reduction of the amount of sugar in the blood. Hence, as we have seen, it is supposed to be due to some toxic product that is i< rmed in the perverted metabolism of the diabetic subject, comparable to acetone, although certainly not acetone itself .f Alcoholic polyneuritis is the form most frequently met with, at anv rate so far as well-marked cases are concerned ; this form preponderates in most countries over all others put together, but at present many of the slighter sensory forms escape recognition, and the preponderance * Lloyd and Riesman, * Trans. Am. Neur. Assoc.,' 1892. f Williamson ('Med. Cliron.,' Nov., 1892) lound in fifty cases of diabetes that the knee-jerk was absent in 38 per cent, and obtained only with reinforcements in 12 per cent. ETIOLOGY. 151 will probably be much less when all cases are recognised. It results chiefly from the stronger forms of alcohol, especially from spirits. It is more common among those who take small quantities frequently than among those who indulge in an occasional " bout " of intem.- perance, probably because the total quantity consumed is greater. Strange to say, it is far more frequent among women than among men, probably at least three times as frequent. The cause for this is difficult to discern. On the one hand continuous drinking is more common among women than is occasional intoxication ; and women who take alcohol to excess generally do so in the form of spirits, while men often take it in the form of beer. At the same time the opposite pro- clivity is seen in the case of delirium tremens, and it would seem as if there were a difference in the nervous system of the two sexes, whereby a susceptibility of the nerves in women replaces that of the brain in men. The amount of alcohol habitually taken, and the duration of the habit before the onset of the affection, vary much. It has been thought that a neuropathic disposition renders a less quantity and briefer period adequate. Other causes often co-operate with alcohol in exciting the disease, especially exposure to cold, and, in the lower classes, insufficient nourishment. Exposure is especially effective in those in whom slight symptoms exist but attract little attention, and the condition of the nervous system is, as it were, prepared for a severe outbreak. Idiopathic Forms. — Regarding these varieties of idiopathic poly- neuritis, little remains to be added to what has been stated at p. 146. The evidence rests chiefly on the post-mortem discovery of the changes in the nerves, but it is probable that more careful attention to the point win show that symptoms are not unfrequent which now receive Kttle attention, or are regarded as functional only. More attention is also needed by the cases in which a neuropathic tendency or some depressing emotion seems to be the cause of this disease, as they may be of the corresponding degeneration of the pyramidal fibres within the cord in "lateral sclerosis," a degeneration which also begins at the extremity of the fibres and extends upwards. Atheromatous Neuritis merits separate recognition on account of ita peculiar mechanism. In these cases the nerves of the limbs have been extensively damaged through atheroma (or " arteritis obliterans ") of their arteries. Necrotic inflammatory processes take place in the parts of the nerves supplied by the affected vessels,, and there result symptoms that resemble those of the toxic form in character, although differing in the greater irregularity of distribution. The symmetry that consti- tutes so striking a feature of the common cases is absent, but arterial degeneration may be symmetrical, and an incomplete rough symmetry- may thus result. It is conjectured that such disease of the nerves will be found to be frequent in the cases in which senile disease of the arteries gives rise to gangrene, and that it is partly through the 152 MULTIPLE NEURITIS. Qigencj of the nem-itis that the gangrene is produced ; but tMs vie"W overlooks llie potent influence of the arterial obstruction itself.* General Etiology. — Multiple neuritis is a disease of adult life. The only form met with in children is that which sometimes accom- panies polio-myelitis, and may perhaps now and then be met with apart from the spinal malady, as an infantile variety of multiple adv-entitial neuritis, irregular in distribution. The other common f onus occur chiefly between twenty and fifty ; the alcoholic between thirty and forty twice as frequently as in either the previous or later decade, but it may be met with up to sixty years of age ; while the rare senile (purely degenerative) variety, and the still more rare arteritic form, are met with at still later ages. Females constitute a majority of the cases, the degree of which cannot yet be estimated; it is due solely to their liability to alcoholic neuritis, in which they amount to at least 70 per cent. The rheumatic and toxaemic forms, on the other hand, occur more frequently in males, probably from their greater exposure to the causes of the disease. More than one cause may co-operate in producing the affection, and then we may distinguish the one as " predisposing," the other as " exciting," although, as a rule, either would be adequate alone were its degree more intense. The double causation can most often be traced when cold or some depressing influence co-operates with alcohol, or when the influence of the latter is conjoined with that of tubercle, as either the primary or secondary cause. Even more frequently the symptoms follow some cause of constitutional depression, inadequate alone. In one case this was an attack of acute gastric catarrh with vomiting, the result of the alcoholism which was the real cause of the neuritis. In other cases a depressing emotion has seemed to be the excitant, and, as we have seen, this appears to be sometimes alone sufficient. In one alcoholic case the injurious effect of painful emo- tion (due to the death of a son) was at once to arrest improvement, and to excite a progressive increase in the symptoms, which continued until death a few months later. Ansemia probably acts chiefly as a predisponent, lowering the nutrition and resisting power of all the tissues, and rendering a slighter cause effective. Thus, in the case of an anaemic girl recorded by Barrs, the symptoms followed immediately on bathing the feet in cold water, when the patient was heated. Symptoms. — The symptoms produced by multiple neuritis differ widely, as has been already intimated, according to the character of the affection of the nerves. They are of three classes — motor weak- ness, sensory distui-bance, and inco-ordination. Psychical symptoms are sometimes pronounced, especially in alcoholic cases. Loss of memory, especially as regards place and time, are the most obvious conditions, but hallucinations, especially visual, are not infrequently * Schlesinger (■ Neur. Cent.,' 1895, p. 578) describes a form of neuritis associated with endarteritis obliterans similar to tliat occurring in syphilis. . SYMPTOMS, 153 present. The motor weakness depends on an affection of the motor nerve-fibres, and usually involves first and cliiefly the flexors of the ankle and extensors of the toes, and the extensors of the wrist and fingers in the forearm, muscles that are homologous and supplied by corresponding nerves, the anterior tibial or peroneal nerve in the leg, the radial branch of the musculo-spiral in the arm. The result is the cha- racteristic "wrist-drop" and "foot-drop," shown in Fig. 58. Other FiGt. 58. — Multiple alcoliolic neuritis; palsy of' extensors of wrist and flexors of ankle. (Prom a photograph by Mr. Hyde Marriott, B.Sc.) muscles suffer in severe cases. The sensory symptoms consist of sub- jective sensations of tingling, &c. ; pains of various character, seat, and degree, often referred to the nerves or deep parts ; tenderness of the skin, nerve-trunks, and muscles, and loss of cutaneous sensi- bility. The inco-ordination resembles that present in the slighter degrees of locomotor ataxy, and is often associated with loss of the muscular sense. These symptoms will be considered in detail. Ac- cordmg to the predominance of one or other of the three sets, corresponding varieties are distinguished, — (1) a motor form, in which there is loss of power with or without the other syrrr^toms; (2) a sensory form, in which there is no marked muscular \-^.„Auess or inco-ordmation, but in which sensory disturbance — irritation or loss — is the chief symptom; (3) an ataxic form, in which, without marked loss of power, with or without sensory symptoms, inco-ordina- tion is the dominant symptom. As mentioned m the introductory section, the varieties of poly- neuritis that are due to special metallic poisons and to certain acute specific diseases are described separately, in the second volume of this work, among the general diseases of the nervous system. The common alcoholic form is alone suitable to convey a knowledge of the general features of the affection, but the account of its symptoms must be completed by some mention of those of the less common forms, which do not need separate description elsewhere. It should 1 le clearly understood at the outset that no set of sym- ptoms is exclusively related to a single cause. The various forms 154 MULTIPLK NKUi;nTS. which depend on the incidence of the disease on the motor or the sensory nerves in preponderant degree, are met with in consequence of each of the common causes, although, as we shall see, some causes give rise more frequently to one form than to another. The onset and course of multiple neuritis vary much in different cases, both of the same class and of the several classes. Premonitory symptoms occur in some cases. They have been observed chiefly in the alcoholic form, but occur in others also. When due to cold or 3ther causes of constitutional disturbance, the special symptoms of the general state may immediately precede the onset. Thus, after exposure to cold, general rheumatic symptoms, with fever, bron- chitis, and other signs of catarrh, may immediately be followed by the symptoms of neuritis. The symptoms that have been regarded as premonitory are especially " numbness " and tingling of the fingers and toes, or of the palms and soles, or the lower parts of the limbs, vaso-motor disturbance in the extremities (as pallor of the fingers), and painful cramp in the calves or elsewhere, together with dull rheumatoid pains. These constitute the first symptoms of the disease, but when they exist alone for months before the onset, they may be regarded as "premonitory." All these symptoms are probably due to the influence of alcohol on the nerves, disturbing the function of the structures whose nutrition undergoes subsequently a corre- sponding impairment. The onset itself may be acute or sub chronic, and is sometimes so slow as to deserve the name of chronic, especially in the slighter sensory form. An acute onset is on the whole rare in alcoholic cases unless the malady is " excited " by some cooperant influence. Thus, in one alcoholic, a prostrating attack of vomiting, lasting for ten days, was followed by an onset of the symptoms of neuritis so acute that at the end of a week the patient was unable to stand, and there was general impairment of sensibility. It is met with chiefly in cases due to cold or toxsemic states ; in these it may be attended by severe con- stitutional disturbance, rigors, and considerable pyrexia. In other forms the elevation of temperature is usually slight or moderate, but sometimes amounts to 3^ or 4°, and may last from one to three or four weeks. The first definite symptom (if it has not existed before) is often the tingling, or " pins and needles " in the extremities, already mentioned, with vague " rheumatic " pains, which become more acute. Motor symptoms are usually soon added, palsy or inco- ordination, or both. They are seldom absent in acute cases. The pronounced symptoms of the disease may resemble in character those produced by the inflammation of single nerves, differing only in distribution, and involving all the functions of the affected nerves ; this is often the case when the malady is acute in onset. But when chronic, as already stated, the fibres may be aftected according to their specific function, and to this the symptoms are then limited, so that they resemble those that are ascribed to a distn.i 1 )ar.ce of special SYMPTOMS. 155 elements of the spinal cord, rather than those of an affection of isolated nerves. The motor form involves either the upper or lower limbs or both, but always the corresponding limbs on both sides, and their distal extremities, the hands or the feet, first and chiefly.* Whichever limbs, arms or legs, present the first symptoms, suffer in greater degree throughout, and it may be alone. The feet suffer more fre- quently than the hands ; motor symptoms may exist in the legs, and only sensory symptoms in the hands, and this when the weakness in the legs is extreme. In whatever part the affection occurs, various sensory disturbances, and especially pains, commonly precede the weakness, and increase with it. They are accompanied by tenderness, generally along the nerve-trunks, but almost invariably in the mus- cles, and sometimes of the skin, These pains may occur in the limbs that do not become paralysed if the action of the cause can be arrested. Although loss of power is the obtrusive feature, some loss of co-ordination generally accompanies it, and is often the means by which the attention of the patient is first directed to the com- mencing disability. lie finds a diflficulty in balancing when standing, or in performing the finer movements with his fingers; and his attention being thus drawn to the part, he finds, on further investiga- tion, that there is some actual defect in the power of extending the wrist and fingers, or in raising the toes or foot from the ground during the forward movement of the foot in walking. Tremor is often con- spicuous in alcoholic cases long before the loss of power. Whenever there is weakness in the leg the knee-jerk can no longer be obtained, probably because the afferent muscle-nerves sufl'er more widely than the motor nerves. The constancy of this loss is very great, and it is not related to any one class of symptoms, but occurs equally in the paralytic and ataxic forms of neuritis. At the same time it is not absolute ; the knee-jerk seems to persist in very rare cases of slight degree, as mentioned on p. 160. "When the first symptoms are in the legs, the first motor loss is the inability to raise the toes from the ground in walking, owing to impei-fect flexion of the ankle-joint and extension of the toes. But this symptom may be to a large extent obscured by the interference v/ith movement occasioned by the tenderness of the muscles and the hyptTBestliesia of the skin, which commonly coexist and prevent the exertion of the amount of power that is possessed. There is a tendency for the nerves of the sole and the palm of the hand to be especially involved in the hyperaesthesia — ^in obedience to a law of pathological susceptibiUty which is to be traced not infrequently in polyneuritis, especially in the tabetic, diphtheritic, and toxsemic forms. These effects of the sensory irritation may render it difficult to deter- mine the common course of the motor weakness, the order in which the * The very vai-inu- symptoms of the disease arc well illnstrHted by an instructive series of cases pulilisliod by Dr. Buzzard. ' Par;dvsis from Peripheral Neuritis,' 1886. 156 MULTIPLE NEURITIS. muscles suffer, and the relative degree of their impairment at different periods. The conspicuous fact is that the muscles first to suffer are those supplied from the external popliteal nerve (anterior tibial group), and these are followed by other muscles below the knee, except in the very rare instances in which palsy does not spread beyond the muscles first affected. The muscles above the knee suffer later and less, and more frequently escape considerable impairment. The flexors of the knee, although supplied by the sciatic nerve, do not suffer more than the extensors, or more frequently, so far as the tenderness permits us to judge. Least frequently and in least degree the muscles suffer that move the hip-joint ; it is only in the most severe cases that these are appreciably affected. Very rarely is the innervation of the bladder or rectum involved in the disturbance of polyneuritis. Interference with these functions may generally be regarded as evidence that the morbid changes are not limited to the nerves, but involve the spinal cord itself. In the arms, the first and chief defect in power is in the extensors of the wrist and fingers. Both arms are affected together or in quick succession— one never suffers alone in considerable degree. Thus the palsy resembles at first, and sometimes throughout, that which is familiar as the effect of lead poisoniag. The resemblance may extend to the escape of the extensor of the metacarpal bone of the thumb, and of the supinator lougus. Lead palsy, indeed, is an example of peripheral neuritis of the "toxic form," and differs from the general form in the limitation of even severe palsy. It seems that the radial nerve (of the musculo -spiral) is that which, in the upper limbs, is the most prone to suffer — a fact which is at present unexplained. It probably depends not on any peculiarity of position, but on some deeper functional relation and position among the nerves of the body, since it obtains when the affection is of the peripheral extremities of the fibres and does not involve all the fibres of the nerve. The radial nerve is homologous with that in the leg of which the fibres are the first to suffer — the peroneal, — regarding which the same facts are true. It is only in the cases due to metallic poisons that the palsy becomes considerable without spreading to other muscles. Generally the flexors of the wrist and fingers become weak, and so do the interossei, while the last to suffer are the thenar and hypothenar muscles. It is rare for the palsy of any muscles except the extensors to be complete. In more severe degree the muscles above the elbow suffer, last and least those of the shoulder. The muscles below the elbow may be abnost powerless when those above it are scarcely affected. In severe cases the trunk muscles are involved — the diaphragm, and the muscles of the thorax and abdomen. Less rarely, but also only in severe fonns, increased frequency of the pulse and palsy of the vocal cords indicate that the fibres of the vagus are suffering. Yeiy seldom the facial muscles, or those of the tongue, are involved. Affection of the motor ocular nerves and of the pupils has been met SYMPTOMS. 157 with only in the most severe cases, and chiefly in those due to toxaemia. Slight nystagmus is common. The nerves of the pharynx and ahmen- tary viscera seem always to escape. It is more doubtful whether this is true of the branches to the lung. Thus the stress of the affection falls on the muscles of the extremities, and those that are affected first also suffer alone in slight cases, and most in those that are severe. As they become weak, and sometimes even earlier, they become tender, and this muscular tenderness usually increases to an extreme degree, and becomes even more obtrusive, in many cases, than the tenderness of the nerves. The limb cannot be grasped, even gently, without cries of pain being elicited, and every change of posture gives rise to distress. This is an important sign, and is no doubt due to the fact that aU the nerves of the muscle suffer, the afferent as well as the motor twigs. Very rarely it is absent. It increases the pain of an electrical examination, and, after a strong current has been applied, the muscles may ache for hours — a fact that should inculcate scrupulous consideration in all such pro- cedures. The affected muscles quickly become flabby and waste, and their prominences disappear. The muscular atrophy becomes extreme in some instances, but the aspect of the limbs differs from that in pro- gressive muscular atrophy on account of the partial distribution of the affection, and because it is only in a few muscles, such as the extensors of the fingers and the interossei, that the wasting is as great as in that affection. Changes in the electrical excitability of the muscles concur with these symptoms ; they present the reaction characteristic of nerve lesions, described at p. 72. The faradic irritability is lost, and that to voltaism is increased in amount, and often but not always altered in quality, in the usual manner. In slight cases, however, increase in voltaic irritability may be trifling, and may be the chief change. In the nerves the irritability to both currents lessens and is ultimately lost. If a case is examined in the very early stage, the increased irritability mentioned at p. 76 may be found, and after- wards replaced by diminution and loss. In the most severe cases the muscles most affected may quickly lose all irritabihty, on account of the intensity of the secondary changes in the muscular tissue, which destroys instead of merely changing their special structure and charac- teristic functions. Occasionally the wasting is concealed by oedema, but now and then the size of the muscles may be little reduced even when they are totally paralysed, with extinction of faradic and great reduction of voltaic irritability. But the wasting is only deferred, and extreme atrophy ultimately occurs. In such cases there is probably a rapid fatty degeneration of the muscles, and the fat accumulates be: ■we -n the fibres so as to maintain, for a time, the bulk of the muscle. An extremely rare alteration is the preservation of some voltaic irritability in the nerves as well as in the muscles, faradic irritability being lost in both. 158 MULTIPLE NETJEITI8. As in other cases of unequal palsy, the less affected muscles of the limbs are apt to undergo contracture and shortening, especially when the palsy causes the part to assume habitually a certain position under the influence of gravitation, or a certain posture is adopted by the patient in order to lessen pain. These contractures occur chiefly in the lower limbs. The foot-drop shown in Pig. 58 is especially frequent, from the palsy of the flexors permitting the foot to fall as the patient lies in bed, under the influence of gravitation and of the unopposed extensors. The effect of posture is seen in the contraction of the flexors of che knee, which may be fixed at a right angle, and to a less degree of those of the hip, on account of habitual flexion of these joints to escape the pain occasioned when the parts are put on the stretch in the extension of the limb. The affection of the sensory nerres of the skin is sometimes absent; more often it is conjoined with that of the motor nerves, and some- times only with that of the sensory muscle-nerves. It very seldom exists alone. Its first manifestation, is the tingling and other sub- jective sensations already mentioned, to which is soon added the hyperaesthesia which is often so troublesome throughout the disease. Sensory disturbance is usually more extensive than the motor palsy, but is greatest at the most affected parts, the extremities of the limbs. Except in slight cases, the damage to the sensory fibres becomes suffi- cient to lessen the sensibility of the skin to touch. A faint touch may be unfelt while over-sensitiveness to pain continues, and is even so intense that a strong touch may cause distress. Rarely, as I have twice seen, sensibility to pain is lost, that to touch being preserved. The temperature sense is usually normal. These sensory changes are first developed on the extremities, sometimes on the palms and soles ; they may even be still more local, and only considerable on the tips of the fingers, or the hyperaesthesia may be chiefly under the nails. Spontaneous pains accompany the hyperaesthesia, dull, or acute, or "burning" in character, referred to the deeper parts of the limb, or the nerve-trunks, or the joints, and increased or excited by any attempt at movement. The pain referred to the joints may be really in them, especially in the gouty, or it may be in the nerves that pass by the joints and are disturbed mechanically by their movement. The sensory change increases in area as the disease develops, and usually extends first up the outer side of the leg and the radial side of the forearm. Although sensibility to pain is seldom lost, the con- duction of pain is delayed in some cases. In the ataxic form, inco-ordination is the chief symptom, and it may accompany the onset of muscular weakness in the motor form. It is usually accompanied by muscular tenderness, and exists with or without the affection of cutaneous sensibihty just described. It pro- bably depends on changes in the afferent muscle-nerves, the impres- sions from which are chiefly concerned in the process of co-ordination (see Spinal Cord, Functions). The implication of these nerves is SYMPTOMS. 159 shown by tlie muscular tenderness that is so marked a feature. The inco-ordination in these cases resembles closely that which exists in tabes, and the knee-jerk is lost as in that disease, while the frequent occurrence of pains in the limbs increases the resemblance. Hence the form ia which this symptom is predominant has been called pseudo- tabes, often with the prefix alcoholic, from the fact that this is its most frequent cause. It has, however, also been met with from arsenical poisoning. The ataxy may involre the arms or the legs, but is most frequent in the latter. It never reaches the degree met with in advanced tabes, probably because very extensive and intense damage to the muscle-nerves only occurs when the toxic cause is intense ; its effect then is not limited to a single set of nerves, but, involving the motor also, produces a loss of power, before which the inco-ordination ceases to be prominent, if it does not of necessity disappear. The general law that limitation needs chronicity of course and moderation of degree holds good ia these cases on the sensory as well as on the motor side. When the inco-ordination is the prominent symptom the disturbance of sensory nerves is slight, and if there is extreme hyperaesthesia and much loss of sensation there is usually also motor palsy ; and thus this ataxic form is not commonly accompanied by the intense sensory disturbance of the complete and characteristic cases. Sensory loss, chiefly to touch, is, however, occasionally met with in chronic cases of the ataxic type. The resemblance to tabes is then still greater. The distinction is considered in the section on Dia- gnosis. Tenderness of the nerve-trunks in the region of whose supply the symptoms are greatest is a very common symptom, although not always readily recognised, because they are only more tender than the adjacent structures, and the degree of difference may seem not great when all the parts are extremely sensitive. It is less frequently a marked symptom than the tenderness of the muscles, and must depend (since the pain is felt at the spot) on the involvement of the nerves of the sheath. It is only in very rare cases, chiefly of irre- gular adventitial neuritis, that any swelliug of accessible nerves can be distinguished. Eeflex action from the skin varies much in its condition. In cases with hyperaesthesia it is often increased, even when there is considerable motor palsy ; the muscles that escape cause the movement, and the impression that reaches the reflex centre is doubtless increased in d(3gree just as is that part of it which reaches the brain and is felt as increased sensation. But ia severe cases, with extensive loss of power and sensation, the skin-reflex may be lost. The loss may be observed to coincide with an increase ia the other symptoms, and generally to be related to loss of sensibnily to touch with extensive motor palsy ; it may, however, be lost when sensation is perfect. Occa- sionally it is lost out of proportion to the other symptoms, motor or seubuiy. The muscle-reflex action (myotatic initabihty), as we 160 MULTIPLE NEUEITIS. have already seen, is almost invariably lost. Altliougli the knee-jerk has been observed to persist in rare cases (Dejerine), its persistence is quite exceptional, and probably depends on the escape of at least some of the fibres on which the action depends. Possibly, however, the knee-jerk is sometimes excessive in the early stages of the disease in consequence of an irritable state of the nerves on which it depends, similar to that which gives rise to the hyperaesthesia. I have more than once found it increased in cases of slight sensory neuritis (e. g. with symmetrical tingling and slight anaesthesia on the soles), and in one such case it disappeared as the disease progressed. On the other hand, it is often lost when there is scarcely any appreciable weakness of the extensors, although usually some tenderness of these muscles suggests an affection of the afferent path. Trophic clianges occur in prolonged cases — in the nails, skin, and hairs, and are similar to those of ordinary neuritis ; glossy skin, arthritic adhesions, and thickening being the most common. Bedsores are not common — a fact well established, but not altogether easy to explain. The vaso-motor nerves may present disturbance of function, and some oedema of the limbs is common, especially in castis that are due to alcohol; the blood- state or impaired function of tte kidneys probably aids in its production. It occurs about the ankle i^, back of the foot, and very frequently about the wrist and back of the hand. In one very severe and fatal alcoholic case the legs and back were the seat of a peculiar brawny oedema, pitting very slowly, and attended with lividity of the skin in the depending parts, which became brighter in colour on pressure. In this case endocarditis developed during the course of the malady. In one recorded case Cfidema was present only over the nerve-trunks in the neighbourhood of joints — a place in which the movement of the limbs especially disturbs the sheath-nerves of the trunks, to which the vaso-motor nerves of the part are probably related. Indeed, it is common for osdema to be present about the joints when it is not elsewhere, and this may be the explanation. Pain in the joints and even some effusion into them have been observed, especially in association with an acute onset, but it is perhaps more often gouty * than rheumatic in alcoholic cases, and its significance as to the " rheumatic " nature of the neuritis must be looked on with some suspicion. It may be occasionally a result of the disease of the nerves, since chronic changes in the joints often take place just as they do in the inflam- mation of single nerves. It is especially common in the finger- joints and in the wrist, but it occurs also in the shoulder and knee, less frequently in the elbow, and in the joints of the leg other than the knee. There is pain on movement and thickening about the joint, with ultimate limitation of movement. It is a troublesome effect of the disease, because it interferes with movement when power returns. • Acute gout, it must be remembered, sometimes attacks the larger joints with oj before the smaller ones, and may closely resemble an attack of rheum.atic fever. SYMPTOMS. 161 There is mticli more tendency to it in some cases tlian in others, and it may be so extensive as permanently to cripple the sufferer.* The adhesions commonly re-form after they have been forcibly broken down. The symptoms are wide-spread in proportion to the acuteness and intensity of the malady, but differ in these respects also according to its cause. The effect of metaUic poisons is usually limited and confined to the arms, as in lead palsy. In alcoholism all the limbs are often affected, but the arms escape more often than the legs. From malaria the legs usually suffer alone ; such cases are considered at p. 185. In cases with complex causation a general parenchymatous neuritis may be accompanied by a preponderant adventitial inflam- mation of some one nerve, as the facial or sciatic. The cases with most widely distributed symptoms are those that result from obscure toxsemic states, from cold, and from alcoholism. It is in these, and especially in the first, that the nerves of the heart, larynx, and of the muscles of respiration most frequently suffer. When the laryngeal nerves suffer it is usual for both adduction and abduction of the vocal cords to be weakened, seldom one movement only. The optic nerves have been affected only in rare cases with considerable blood- change. In the case mentioned on p. 160 (in which there was brawny oedema and endocarditis) there was slight optic neuritis and a diffuse cedematous retinitis.f The face has also been affected on both sides in some of the cases due to exposure to cold, and also, usually in shght degree, in some toxsemic cases; it seems always to escape in cases due simply to alcohol. The sphincters almost always escape; a slight impairment of function has indeed been met with in a few very severe cases of probably pure polyneuritis, but their affection, as already stated, usually indicates an implication of the spinal cord. The Course of the affection is determined by the same conditions as mfluence its intensity, and by the extent to which the cause is imder control. The more severe and acute the symptoms, the wider is their range and the longer is their diiration. Very commonly the symptoms increase during three to six weeks, then become stationary (if the cause is stopped), and after one or two months slowly improve. The first sign of improvement is a diminution in the pain and hyperaesthesia, but the tenderness of the muscles and the nerve-pains on movement often continue long after the spontaneous pains have ceased. If tingling, &c., ceased as the disease advanced, their return may herald improvement. Power slowly returns, first in the muscles affected last and least, and afterwards in those paralysed and wasted tn greater degree. In these the weakness lasts for many months, and shortening of the opponents of the most affected muscles is apt to occur. The contracture of the caK muscles, secondary to palsy of the flexors of the ankle, constitutes a grave hindrance to the use of the legs in standing • As in a case recorded by Taylor, * Guy's Hosp. Eep.,* 1888. t The changes are described by Edmunds and Lawford, ' Trans. Opb- See.,* ix, 137. VOL. I. 11 162 MULTIPLE NEUniTlS. and "walking. The patient cannot get th.e s6le and lieel on tlie ground so as to afford a uniform base of support, and keep Ms body upright so as to balance it. But this contracture invariably yields to persistent efforts to walk. The palsy of the arms lasts longer than that of the legs, or vice versa, according as the one or other suffers most. The excess of impairment of the muscles most affected is often very con- spicuous .during recovery. Improvement goes on for a long time, generally until recovery is perfect, but very rarely there is some per- manent loss of power. It is remarkable, however, how almost complete a recovery may take place, even after the paralysis has been consider- able for a year. The wasting lessens and power returns ; latest where there is most loss of irritability, and usually later in the small muscles of the hand than in the muscles of the forearm. Relapses are apt to occur, but only when the cause of the neuritis is still in operation in some degree, or when the patient is again exposed to it or to some adjuvant cause, such as cold. But the malady sometimes runs a very acute course, especially in the cases due to toxaemia or to cold, so that all parts of the limbs have become weak and the extremities powerless by the end of seven or ten days, and the involvement of the nerves of the respiratory muscles may bring life to an end within a fortnight, sometimes even within a week. In this form there may be severe initial pain, not specially related to the regions afterwards affected. In one case it was severe in the back, in another across the abdomen. It is probably a direct effect of the blood- state, distinct from its influence on the peripheral nerves. Such cases bear considerable resemblance to those of " acute ascending paralysis " in their course — differing, however, in the fact that the asceasion is up the limbs rather than up the general frame. Sometimes, on the other hand, the disease presents a course far more chronic than that described above, and occupies many months in its development and progress. This is often the case with the limited alcoholic forms, especially the ataxic variety, " pseudo-tabes," and with cases in which the toxic agent is absorbed from without very slowly, and its effect accumulates gradually, as in some cases of chronic arsenical poisoning. Slight cases, again, treated promptly have been known to recover in a month. The temperature, usually raised in an acute onset (see p. 154), may be normal in chronic cases, with or without an occasional rise, or may be sHghtly raised during the chief part of the course of the disease. A persistent considerable elevation suggests some comphcation, such as phthisis, and should lead to careful and repeated examination of the lungs. It may also indicate a persistence of toxaemia, other indi- cations of which are mentioned among the complications of the disease. The Cause of Death in acute cases is often palsy of the respiratory muscles, sometimes aided by a catarrhal bronchitis, or paralysis of the heart when the vagus is affected ; in more chronic cases it may be caused by exhaustion, due to chronic gastric derangement and the COMPLICATIONS. 163 wearying effects of prolonged siiffermg, or the effects of disease of tlie spinal cord. Pneumonia frequently causes death in the acute forms, and in alcoholic subjects the inflammation of the lung so often runs a, low course, with extensive consolidation, sometimes bilateral and unusual in seat (as in the middle lobe and central portions of the lung) , that it is difficult to avoid the suspicion that its form and course are determined by coincident neuritis of the pulmonary branches of the vagus, either primary or secondary to the inflammation of the lung. Death may result unexpectedly from cardiac failure when no preceding symptoms have suggested an affection of the cardiac nerves, and in such cases there is generally a coincident degeneration of the walls of the heart. Fatal neuritis of the vagus, however, may occur very early in relapses. Other coincident effects of chronic alcoholism are frequent causes of a fatal issue, such as cirrhosis of the liver, gastric troubles, and chronic cerebral meningitis in cases of alcoholism, or acetonsemia in cases of diabetic polyneuritis. Various morbid blood-states, causing the neuritis, may continue and cause death. Lastly, phthisis is a fre- quent cause of death, and probably varies in the relation it bears to the neuritis, sometimes being its consequence, and sometimes appa- rently a coincident effect of some obscure cause. Complications. — The chief of these have been just enumerated in the hst of the causes of death. The most important in alcoholic cases are the effects of alcohol on various organs and tissues, especially on the liver, heart, and spinal cord. It is very common to find the liver enlarged, sometimes very large ; less commonly it is contracted. The enlarged hver may be either fatty or fibroid. Ascites and other effects of portal obstruction are much less frequent complications than might be expected, perhaps because it is rare to have much contraction of the new tissue in the liver. The kidneys also are often diseased. Gastric catarrh with its varied symptoms, morning vomiting, anorexia, and the hke, is very common. So also are the several effects of gout due to the alcoholism or to metallic poisons when these have been the cause of the neuritis (as lead, or, as in one case under my notice, silver). On the part of the nervous system there may be various subacute and chronic forms of inflammation of the substance of the spinal cord or of its membranes, the common manifestations of which are to a large ex- tent prevented by the affection of the nerves. The most important, the ti-unk girdle-pains and the affection of the sphincters, are further con- sidered in the section on Diagnosis. Chronic cerebral meningitis is also common, and usually fails to produce its common manifestation, pain, even when marked and extensive opacity of the membranes and increase of fluid are foTind after death. It usually causes some chronic mental disturbance, often shght optic neuritis, and sometimes general convtd- sions. But mental change is also common as a direct effect of the alcohol on the brain ; distinct delirium tremens often coincides with the onset of the neuritis. In most alcohohc cases, indeed, the mer.tal state is imnatural ; the patient is irritable, intolerant of pain, and deficient in 164 MULTIPLE NEURITIS. self-control. Yarious manifestations of hysteria occur in women, and a peculiar childish jocularity is sufficiently common to deserve special mention. The craving for withheld stimulants increases the irritability, and, in the case of women, previous training in duplicity in order to obtain alcohol has usually induced a general deterioration of the moral sense, which has results that startle those who have been successfully d?ceived. Mental change is for the most part absent in the cases due to cold (save in some in which there is an intense blood-change) , and in those produced by metallic poisoning ; but it occurs frequently in toxaemic cases, generally in the form of simple delirium, and is appa- rently due to a simultaneous action of the morbid agent on the cells of the brain. A persistent morbid blood-state may cause endocarditis and other consequences. Phthisis is also a very frequent complication ; its double relation to the neuritis has been ah-eady mentioned. The form of lung disease met with in neuritis presents no special peculiarities, except that low pneumonic changes play a considerable part in the morbid process. Acute pneumonia is also common, and in the cases in which it does occur almost always fatal. PATHOLoaicAL Anatomt. — The changes in the nerves correspond to those already described in the account of neuritis, with the exception that the chief changes of isolated neuritis are in the connective tissue, and especially in the sheath ; and those in the nerve- fibres are subor- dinate. In bilateral neuritis the connective tissue presents very trifling changes. Some variations are met with in this respect ; when the dis- tribution of the affection is not strictly symmetrical, the sheath and interstitial tissue suffer in greater degree ; in proportion to the acute- ness and symmetry of the symptoms, the changes are restricted to the nerve-elements, and the connective tissue is unchanged, but in some cases both the connective tissue and nerve-fibres are involved, as in Fig. 59. This is also the condition when there is acute inflamma- tion spreading from the one constituent to the other, as in the case of fatal septicaemic neuritis recorded by Roth (see p. 148). In the vast majority the nerve-elements are affected chiefly or even exclusively; the changes are essentially "parenchymatous." It is remarkable, indeed, how slight is the affection of the connective tissue and sheath, e^en in nerve-trunks that have been extremely tender. Hence it is probable that this tenderness is often due to changes in the nerves of the sheath, the " nervi nervorum," similar to that which the pn per conducting fibres of the nerve undergo, rather than to an inflammation of the connective tissue itself. Naked-eye changes are present only when the connective tissue and sheath are iaflamed in considerable degree. In recent and acute cases of this character the nerves may be found reddened, swollen, and sometimes small haemorrhages are visible. In older cases they may or may not be swollen, but are usually softened, and even pulpy. When PATHOLOGICAL ANATOMY. 1G5 the changes are confined to the nerve-fibres, diminished consistence may be the only alteration that can be recognised on simple examina- tion ; and often this is absent, and the nerves appear normal on external examination, even when their fibres are extensively disintegrated. Sometimes under a low magnifying power a section of the nerve has a mottled aspect, due to the irregular destruction of the fibres. When the connective tissue is involved the microscope shows the sheath to be infiltrated with lymphoid cells, and in old cases many spindle-cells and fibres increase the bulk. The same changes may be traced in the septa between the fasciculi, and in the secondary sheaths that surround the latter. The walls of the vessels are also thickened (Fig. 59, a). When mere acuteness of parenchymatous neuritis causes the connective tissue to be inflamed, the interstitial tissue and inner part of the sheath are chiefly affected, and an amorphous " exudation " may be found in these situations. But the fibres themselves always suffer in conspicuous degree; and in the majority, as in the case from V Pia. 59-— Multiple alcoholic neuritis; sections stained with carminp and cleared. A. Transverse section of part of sciatic nerve; low power. B. Part of a fas- ciculus of same, more hig-hly magnified. 0. Part of a less affected fasciculus from a musculo-spiral nerve. which Eigs. 69 and 60 are drawn, they suffer chiefly, the interstitial tissue presenting comparatively little change. In this case the changes were not purely toxic ; there was a complex state, combining inflamma- tion of the fibrous elements of the nerves with the purely parenchyma- tous change. The patient was a woman aged thirty-three, alcoholic ; the course of the disease was subacute ; the symptoms reached a considerable degree in a few weeks, and the patient died, chiefly from coincident liver disease, five months after the onset. The symptoms were characteristic, and continued up to the time of death. The fibres present the alterations met with in all acute forms of neuritis, 166 MULTIPLE NEURITIS. essentially tlie same as tliat wHcIl occurs after an injury to a nerve, represented in Figs. 33 and 34 (p. 66), and, associated with inflam- mation of tlie sheath, in Fig. 44 (p. 83). Examination in the recent state reveals abundant products of the degeneration of the fibres, granule corpuscles, &c. There is a slight increase in the connective tissue between the fasciculi ; the area of these is occupied by ti-acts of interstitial tissue, which under a higher magnifying power (b) have a branching form, enclosing spaces which have been occupied by nerve- fibres, and in some of which healthy fibres still remain (c). The space between this tissue is occupied by the products of degeneration of the fibres, but these are rendered invisible by the clearing process, and only faint indications of their outline can be seen (b). In sections stained with osmic acid and mounted in glycerine (Fig. 60) these products of Fia. 60. — Sections from the same sciatic nerve, stained with osmic acid and mounted in glycerine. A. Fasciculus under low power. B. Part of a fasciculus more highly magnified. 0. Longitudinal section of nerve-fibres. (Prom sections prepared by Dr. Beevor.) degeneration, stained dark, are conspicuous. Under a low magnifying power (a) a fasciculus is seen to be studded with black granular spots, elongated where the fibres are divided obliquely ; the increase in the tissue between these degenerated fibres is distinct; aggregations of myelin are seen in the connective tissue between the fasciculi. Under a higher power (b) the dark spots are seen to be the sections of degenerated nerve-fibres, in some places two or more being blended into a larger mass. In a longitudinal section (c) the process of degeneration of the fibres is more distinctly seen, and from it the appearance of the transverse section can be better understood. The white substance is broken up and enlarges the fibres at some places, while at others it has been removed, and the sheath is left empty. Eound masses of myelin lie (on the left) outside the fibres. The nuclei of the fibres are enlarged ; one, of considerable size, is seen in the centre of the figure. Connective-tissue fibres and cells lie between the nerve-elements, and near the sheath are round and spindle cells containing myelin granules and globules which they have taken up (b). The distribution of the changes in the nerves varies much ia diferent cases. The signs of inflammation of the sheath may exist PATHOLOGICAL ANATOMY. 167 only in the larger and medium sized nerves of tlie limbs, and in the smaller nerves the changes may be confined to the nerve-fibres. These may be traced down into the intra-muscular nerves and their endings. On the larger nerves the signs of inflammation cf the sheath are most intense at certain spots, especially (as in simple neuritis) where a nerve turns round a bone, or passes through a fascia, or divides, or in the neighbourhood of joints, their situation being probably determined by mechanical influences. As a very rare complication, changes in visceral nerves have been observed. Severe cohc after influenza was found to be attended by signs of inflammation in the nerves and gangha in the abdomen.* In all cases in which the affection is chiefly of the nerve-fibres them- selves the changes are usually intense in the peripheral parts of the nerves, and as the nerves are examined farther from the periphery the alterations become progressively sHghter, and the proportion of normal fibres larger, until the morbid appearance ceases. The centripetal extent of the disease — that is, the degree in which the larger trunks are affected — varies according to the duration and severity of the case. If the nerve-fibres could be isolated and seen like the branches and twigs of a tree, as they separate in the peripheral ramifications, we should see the endings and twig-like branches withered, and as the branchlets become larger and larger by junction they would assume a more and more normal aspect until the larger branches appear perfectly natural. The size of branch to which the change extended would vary according to the severity of the case. In some instances even those of largest size would present some alteration, while in others the small twigs would be withered in a considerable part of the tree, although the change did not extend beyond them. In a tree the leaves would drop off equally whether the twigs only were diseased or the branches also; and so the muscles suffer equally whether the nerve degeneration is limited to the periphery or extends to the nerve-trunks. In the case from which the illustrations are taken even the sciatic nerve presented few healthy fibres ; but here, as usual, the anterior roots were healthy. This limitation to the peripheral extremities of the nerves is met with in slight cases of considerable duration, but also in some severe cases of very brief duration. For instance, in a case accompanied by pneumonia, and fatal in seven days, the only change found was in the fibres themselves within the muscles ; it was a motor parenchymatous neuritis. The character of the changes is also influenced by that of the nerve-fibres involved. If the affection is partial, as in the ataxic or the purely motor forms, the mixed nerves contain many healthy fibres mingled with those that have undergone atrophy. When the symptoms are both motor and sensory almost all the nerve- fibres are found to have suffered. The nerves of the limbs alone present changes in the majority of cases, but in severe and acute cases almost any nerves may suffer, and • Ferguson, 'Alienist and Neurol.,' 1890. 168 MULTIPLE NEURITIS. this in wide extent. Tlie corresponding nerves on tlie two sides aro almost always affected. 'Ihe musculo-spiral nerve in the arm and the anterior tibial nerve in the leg usually suffer first and in greatest degree, but often all the terminal nerves of the limbs are involved ia some measure; in the lower leg the anterior tibial almost always presents more change than the other nerves of the same level, and in the thigh the sciatic more than the anterior crural. In the arm the median and musculo-spiral and ulnar all suffer, but the alteration in these nerves in the upper arm may be slight when it is considerable in their branches in the forearm. The changes occasionally met with iu other nerves correspond to their implication, as described in the section on symptoms. Various irregularities in distribution are met with in cases dependent on special features of the causal toxine, the varieties of which are extremely numerous, as we are only now beginning to perceive. Central Changes are sometimes met with. There may be acute or chronic inflammation, synchronous effects of the cause of the neuritis. An example of such myelitis is figured in the chapter on chronic myelitis at a later page. More important and at present more obscure are alterations in the central elements on which the nutrition of the neuron depends, of the same parenchymatous nature as the peripheral changes. Capillary haemorrhages have also been found.* The Muscles present changes of the same character as those which result from ordinary neuritis (see p. 70). They are paler than normal and smaller in bulk. The fibres are reduced in size, and pale ; the transverse striation may be preserved, or they may be granular; normal fibres may be found side by side with those that are degene- rated. The nuclei of their sheaths and of the interstitial tissue may be increased in number, and often are arranged in groups ; and sometimes a quantity of such nuclei and leucocyte- like cells may separate widely the fibres, and granular and pigment masses may accumulate between them. In very acute cases the changes in the muscles may be great, and alike parenchymatous and interstitial ; the fibres presenting loss of their striation with fatty and granular degeneration, while there may be a great increase in the amount of the interstitial tissue, espe- cially of its nuolear elements—:-" acute interstitial myositis."t This change is described at a later page (p. 185). In many cases there has been merely a general increase in the con- nective tissue throughout the cord, which has been in some instances * Pal, ' Neur. Cent.,' 1891. He also found degeneratiou iu the lateral and posterior columns, and similar alterations have been since described by others. Ballet, * Prog. Med.,' 1896, Nos. 18 — 26. A controversy has arisen such as to cause some French observers to be termed " centriiliste," and others " peripheraliste," the one holding that the cell is the first to be affected, and that the peripheral ))art suffers secondarily ; while the others maintain that the normal aspect of the nerve- roots is incompatible with this view. Ballet discusses the question, but without deciding it. t See Senator, ' Zeitschr, f. kl. Med.,' 1889. PATHOLOGY. 169 greater in one region than elsewhere, and especially marked in the posterior columns. Such alterations are most marked in chronic cases in which the symptoms have continued for months, and especially in those due to chronic alcoholism, or in which life has been prolonged in a state of disability. Other organs are often found diseased, and in alcoholism the lesions common in that disease are generally found in some degree, especially alterations in the liver and kidneys. The former may be large and either cirrhosed or fatty ; the kidneys are generally large and opaque, sometimes with fatty striae in the cortex. Pneumonia is frequent both in these and in all cases due to causes that induce an intense change in the blood. In these there may also be enlargement of the spleen, such as is met with in typhoid fever and septicaemia. Phthisical changes in the lungs are also common in chronic cases, both in those that are due to alcohol and in others. No special peculiarity has been observed in the pulmonary lesion, but it is very desii'able that more attention should be paid to the state of the nerves of the langs entering the diseased parts. When not otherwise diseased, the lungs are generally found to be the seat of terminal congestion and oedema. The walls of the heart may be degenerated, and alterations may some- times be found in its nerves. Pathology. — An outline of the chief facts in the pathology of mul- tiple neuritis has been given in the introductory section, and not much remains to be added. The relation of the motor symptoms to the lesion of the nerves has also been described in the general account of diseases of the nerves, and in the description of isolated neuiitis ; all that has been said of the single form is true also of that which is multiple. The wasting that accompanies the loss of power, and the change in electrical irritability, are the same in each. In each it is true, more- over, that the position of the lesion in the course of the nerve-fibre makes no difference to the symptoms ; these are the same whether the disease is in the trunk of the nerve, the peripheral fibres, or the actual nerve-endings. The relation of the ataxy in the pseudo-tabetic form to a neuritis of the afferent muscular nerves is proved partly by exclusion, partly by analogy, since in true tabes the lesion may be confined to these; the spinal cord may be free, and only the peri- pheral nerves diseased. The evidence for this will be described in the general account of the functions and symptoms of diseases of the spinal cord, and in the chapter on locomotor ataxy — a disease which sometimes not only resembks, but is almost identical with, the pseudo- tabetic form of neuritis. The pains and hypersesthesia are explained by the fact that the disease of the nerves is one in which the nerve- fi.bres themselves suffer primarily, and that on them the cause must have a primary and direct action.* An influence which leads to the * In the first edition 1 suggested that the degeneration of some of the fibres might be secondary to their damage by the inflammation of the sheath and inter- •titial tissue at some higher spot. But this now seems very unlikely; it is far 170 MULTIPLE NEURITIS. molecular destruction of the nerve-fibres must, in destroying their structure, disturb gravely their function; and this disturbance of structure and of function proceeds in the parts still connected with the nerve-centres, so that the irritative influence of the molecular changes can act on the centres by the normal upper parts of the nerves throughout the whole course of the malady. It induces in the centres, as all prolonged pain does, an undue readiness of action, a state of over-excitability; and so we can understand the persistence of the pains and hypersesthesia, and the fact that these continue until the process of restoration has become definitely established. The same considerations apply to the tenderness of the muscles, since the afferent muscular nerves correspond in the direction of their function to the sensory nerves of the skin. In both cases mechanical influences constitute the chief mode of their normal stimulation, and hence they may well be morbidly sensitive to such influences. The peripheral distribution of the changes indicates, moreover, that pro- bably the first to suffer are those in which functional susceptibility is most highly developed — the actual endings of the nerves, and the structures which are especially adapted for the reception of stimuli and the production of nerve-force. We have seen that two facts give us the key to the pathology of the disease so far as this is yet understood. One is its symmetry ; the other is the fact that it is commonly a disease of nerve- fibres — that these, and not the connective tissue, are the parts primarily and specially diseased. In all structures, in proportion to the intensity and acuteness of the parenchymatous affection, the interstitial tissue participates in the changes, and escapes in proportion to its slowntss and slightness. The extent to which this is true of multiple neuritis has been already pointed out. Further, in its relation to a morbid blood-state as its sole cau^e, we have the key to the symmetry of the affection as well as to its parenchymatous nature, and on this point there remains little to add to what has been already said. Such a limitation to the nerve-fibres as is seen in multiple neuritis is unknown in the isolated form, in which, as in gouty or syphilitic neuritis, the affection is chiefly one of the sheath and interstitial connective tissue; and the fibres suffer only secondarily in chronic cases, although, in accordance with the law abeady stated, they are involved in acute cases in proportion to the intensity of the process. It is not surprising that the symptoms of polyneuritis should bear so close a resemblance to those of some affections of the spinal cord, since we must regard the peripheral nerves, at least the motor fibres, as essentially outlying parts of the cord, and it will be seen that one central disease, primary lateral sclerosis, presents many points of correspondence with the chronic form of polyneuritis, being more probable tbat all the fibres sufPer in the same way, and the more thoroughly cases are studied the more clearly does it appear that all symmetrical neuritis is peripheral and parenchymatous. PATHOLOGY. 171 an affection of the fibres proceeding from tlie motor cells of tlie brain analogous to that of the fibres proceeding frora the motor cells of the cord. We can understand the peripheral distribution of the disease by the fact already pointed out — that the nerve-fibres are really the prolonged processes of the nerve-cells, sharing the life of the cell, and depending on it for their vitaUty. The influence on which their life depends must lessen with the distance from its source, and hence their vital power of resisting morbid agencies is least at the periphery. The conditions of life of the sensory fibres, it need hardly be pointed out, differ little from those of the motor, since the ganglia containing their cells are near the cord, and almost as far from the periphery as are the motor nerve -cells. This fact also has a relation to the paren- chymatous nature of the disease, since we can find no reason why the connective tissue of the nerves should suffer most at the extreme periphery. On the contrary, the inflammations that begin in the sheath are generally situated in the course of the nerves, at some spot exposed to the influence of an exciting cause such as pressure or motion. The same fact (that the cause is a blood-state) affords also an explana- tion of many facts of distribution. In addition to the points already mentioned it is only necessary to point out how common are instances of selective action of toxio agents upon various parts of the nervous system ; and analogy prevents us from feeling any difiiculty in at least accepting the fact that a blood-state should act upon one set of nerve- fibres rather than upon another, or on the fibres for the extensors, or even first and chiefly on only some of the nerve-fibres of a certain set of muscles. We do not yet know what are the influences that deter- mine such susceptibility, but it is probable that a very sHght difference in nature is sufiicient to determine a very great difference in the result. The fact of symmetry excludes, as we have seen, any other causal influences than those which act through the blood, or consist in a vital tendency, and act on all structures with similar vital conditions. We know nothing as yet of the precise character of the morbid influence which causes the malady, beyond the facts mentioned in the intro- ductory section. 'Ihe greatest difficulty is presented by the fact that a poison generated through exposure to cold, or possibly by a growth of organisms in the body, should have an influence similar to that which is exerted by metals or by alcohol. At the same time it is instructive to note that the most recent researches in bacteriology point to the pro- duction of chemical substances by the disease-causing organisms in the com-se of their growth, and suggest that these chemical products, rather than the organisms themselves, act upon the nerves.* Alcohol, it may be further noted, is itself the result of the growth of organisms almost as low in the scale as those which are the causes of disease ; the process of the growth of bacteria in the body may be not unlike a process of fermentation, and the results of the one not unlike those or the other. The analogy is the more pertinent, since multiple neuritis * A theory apparenily tirst suggested by Kosenheim, ' Arch. f. Psych.,' xviii, 3. 172 MULTIPLE NEURITIS. is not known to be excited by any other organic poison than that which is so produced. The forms of polyneuritis ascribed to anaemia and cachexia, &c., may be a simple failure of nutrition in those structures of the nervous system that are farthest removed from the centres ; but the possibility must not be forgotten that imperfect tissue changes may generate a toxic agent capable of acting on these nerves, analogous to that assumed to be effective in diabetes.* The changes in nutrition are sufficiently explained by the alterations found in the nerves, in accordance with the general facts of trophic disturbance stated at pp. 27 and 65. That in the muscles corresponds in distribution to the changes in the motor nerves, that in the skin and joints to those in the sensory nerves. All trophic changes which resiilt from ordinary nerve-lesions must be ascribed to the propagation downwards of the influence of the defective and abnormal nutrition ; and hence it necessarily follows that such abnormal nutrition, beginning in the nerve-endings, should have a similar influence, since it is through those nerve-endings that the effects of higher lesions are transferred to the tissues. The law already stated holds good here also, — that changes in nutrition are in proportion to the intensity and acuteness of the disturbance in the nerves. All that has been said regarding such changes in the sldn, in diseases of isolated nerves, is true also of the multiple form, and even more clearly in the case of the motor nerves and muscles. The more acute the process in the nerves, the more intense is the change in the muscular tissue. One special point, indeed, arises in this connection. Although, in very acute isolated neuritis, the muscles may undergo the same intense and destructive changes seen in the most acute forms of multiple neuritis, it is possible that the extreme changes in the latter are sometimes a result and evidence of a direct action of the blood-poison on the muscular tissue itself, t There are some facts of both physiology and pathology which suggest what may be called a certain degree of solidarity of relation between the substance of the nerve-endings and that of the muscular fibres on which they terminate. This may lead to a common susceptibility to suffer from the same morbid influence, so far less in the muscle that only when the influence is very intense does its nutrition suffer directly to a considerable extent. Diagnosis.— There are few diseases in which an early diagnosis is of greater importance. Prompt treatment would save many patients from months of suffering and disability, since the removal of the cause * This analogy is borne out by the occurrence of degenerative changes in the epinal cord, occurring in association with profound anaemia, as described by Licht- heim and others. t This suggestion has been made by Soemerling as an explanation of the very intense changes found in the muscles in one acute case. In beri-beri the change in the cardiac muscle is not infrequently very great, and quite out of proportion to that found in its nerves. DIAGNOSIS. 173 ensures with certainty, during a gradual onset, a quick removal of the aymptoms, whereas its effect on the developed disease is manifested much more slowly. These remarlvs apply especially to the alcoholic cases, but in some of the others the patient may be saved further exposure to the cause if the disease is promptly recognised, or early treatment of the blood-state may have a considerable influence in lessening its effects upon the nerves and ameliorating the course of the affection. The diagnosis of multiple neuritis is becoming far less liable to error. It depends on the motor and sensory symptoms above described, their correspondence in function and distribution ia the opposite limbs, their pecTiliar symmetrical localisation in the extremities in the first instance, and on the tenderness of the skin, nerve-tronks, and muscles. Symmetrical weakness of the extensor muscles situated in the forearm, and of the corresponding muscles in the lower leg, or of either of these, is the leading diagnostic motor symptom. Bilateral wrist- drop or foot-drop suggests multiple neuritis, and hyperaesthesia or deep tender- ness gives strength to the opinion. It is, however, most important to remember how widely the symptoms vary both ia different forms and in different cases of the same form. The acute rapidly fatal cases,, with palsy quickly becoming general, are of a type quite Tinlike the chronic cases in which one group of muscles on each side suffers alone ; while there is a positive contrast between the latter and a case of " pseudo-tabes," in which ataxy and pains are almost the only sym- ptoms. In chronic cases the early pains are often mistaken for those of rheumatism, and in those of acute course, especially when due to cold, these pains suggest the onset of rheumatic fever rather than of any affection of the nerves. The seat of the pains, however, is not that of rheumatic pain, and their association with tingling in the extremities should excite a suspicion that they are of nerve origin even before muscular weakness renders their nature clear. It must be again pointed out that pain near a joint, produced by movement of the joint, is easily mistaken for pain in the joint, even when it depends entirely on tenderness of the adjacent nerves. In some cases the pain is regarded as neuralgic, especially when it is seated in the arms and hands, and is perceived to be in the nerve-trunks or branches. But the general elements of the diagnosis between neuritis and neuralgia usually suffice for the distinction, the most important point being the persistence of tenderness and hypersesthesia in neuritis, relative excess of the spontaneous pain, and also the development of symptoms that indicate damage to the conducting fibres. The bilateral symmetry of the pain should also help to prevent error ; true neuralgia is essentially a unilateral disease. A gouty diathesis may increase the difficulty of the diagnosis, especially in cases of alcoholic neuritis ; but the pains of gout are unequivocally articular or muscular. The symptoms resemble most closely those of certain diseases of the spinal cord, especially acute and subacute inflammation of the grey 174 MULTIPLE NEURITIS. mattei* — polio-myelitis. Until recently, indeed, all cases of multiple neuritis were looked upon as of that nature. It is chiefly in the rheu- matic and toxasmic forms that the diagnosis is really difficult. In each disease there may be a febrile onset, muscular wasting with the reac- tion of degeneration, initial rheumatic pains, and a tendency to the spontaneous recovery of the least affected parts. The distinction rests on the symmetrical localisation of the neuritic palsy, while that of polio-myelitis is characteristically random ia distribution ; on the persistence and severity of the neuritic pains ; on the tenderness of the inflamed nerve-trunks ; and on the changes in sensibility, a symptom never present in polio-myelitis. The electrical reactions are the same in both affections. It has been said the early extinction of voltaic iriitability in the muscle (see p. 72) is met with only in disease of the nerves, but this is incorrect; I have more than once met with it in central affections. But we have seen that it is probable that the nerve-trunks are sometimes inflamed in polio -myelitis, and suffer as a simultaneous effect of the cause of the spinal lesion. In this con- dition, however, the spinal symptoms preponderate, and the distri- bution of the neuritis is irregular. In all cases the presence of increased myotatic irritability, or of the spasm in the legs that accom- panies considerable excess of this, may be taken as proof of disease of the cord; all active muscular spasm, indeed, has this significance. Thus if the arms are paralysed, even though the paralysis closely resembles that of polyneuritis, and the legs are weak, with excessive knee-jerk and foot- clonus, the disease is of the cord, and not of the nerves. The greatest difficulty is presented by some sensory cases in which there are only tingling and numbness in the legs, and also by the problem of detecting cord disease in the presence of peripheral neuritis. The latter will be considered further on. The former is generally decided by the presence or absence of the knee- jerk, and by the fact that in peripheral neuritis the sensory symptoms are more peculiar and symmetrical than in cord disease; there is tingling or anaesthesia, for instance, in the palms or soles, or both, and a careful examination of the nerves and m.uscles will generally reveal a condition that is characteristic. Pachymeningitis, damaging the nerve-roots, m.ay cause paralysis, wasting, and ansesthesia, but in this all four limbs are not affected; the legs rarely suffer ; the anaesthesia invades the upper parts of the limbs or the trunk as much or more than the distal parts ; there is no tenderness of nerve-trunks, and there is usually distinct evidence of damage to the spinal cord itself. The mysterious disease, " acute ascend- ing paralysis," may resemble the most rapid form of multiple neuritis, but in it the symptoms ascend the trunk from the legs to the arms, and do not begin in the hands and feet at the same time or successively, and involve the trunk last, as does the usual form of multiple neuritis. Many cases, perhaps indeed most, are of toxic origin, and are really neuritis. Diphtheritic paralysis is of uncertain nature, but there is no DIAGNOSIS. 175 considerable pain, and the weakness in the limhs usuallj succeeds paralysis of the palate and ciliary muscle, never met with in other forms of polyneuritis. The distinction from other diseases (as, for instance, that from the symmetrical paralysis of the extensors which may occur at the onset of progressive muscular atrophy) will be con- sidered when these diseases are described. The distinction of polyneuritis in its ataxic form, "pseudo-tabes," from true tabes is often beset with great difficulty. This is indeed natural, since the lesion in true tabes may be identical with that in the neuritic affection ; not only is degeneration of the peripheral nerves a common lesion in tabes, having the same distribution at the peripheral extremities of the ne.ves as in polyneuritis, but in the variety termed " neuro-tabes " the lesion consists only in this nerve degeneration, and the spinal cord is free from disease. We have, then, affections iden- tical in pathological anatomy, and almost identical in symptoms. Yet we must class the neuro-tabes with the spinal form, from which polyneuritis, as here described, has to be distinguished ; it is necessary to do so on account of the relations and etiology of the two maladies as well as on account of practical considerations. The presence of actual paralysis, of distinct weakness of the extensors, in addition to inco-ordination, would of course decide the question, since there is no actual loss of power in tabes : hence a distinction in gait pointed out by Westphal and Charcot, that in pseudo-tabes the feet are raised too high on account of the difficulty of getting the toes off the ground (like a person stepping over low objects), is of little actual value ; it only exists when there is distinct loss of power. But it is in the cases of neuritis in which there are only sensory symptoms that |;he difficulty especially exists. It occurs, moreover, chiefly when the ataxy is moderate in degree ; when this is so great that the patient is not able to stand alone, in spite of the power of moving all joints of the legs with fair force, true tabes should alone be thought of. The cases of tabes in which there is moderate inco-ordination of movement, distinct uno.eadiness on walking, whether increased by closure of the eyes or not, and distinct irregularity and uncertainty in the move- ment of the feet and legs, are those which are joerfectly simulated by the pseudo-tabetic form of polyneuritis. Pains are common to the two diseases, and neither prolonged acute pain nor dull rheumatoid pains afford the means of distinction. True "lightning" pains are seldom met with in neuritis ; they are therefore strong evidence that the case is one of tabes. Extreme hyperaesthesia is much more common in neuritis than in tabes, but is of little service in the diagnosis because it is not often present in ataxic polyneuritis, but the muscular tender- ness of neuritis is of considerable diagnostic value. A great excess of tJie reflex action from the skin is occasionally met with in tabes, the sensory impressions being painless ; while in ataxic neuritis the reflex action is seldom excessive, and is generally diminished, while the sensory impression, is commonly painful from the hyperaesthesia. 176 MULTIPLE NEUUITIS. Some other symptoms are also of value as indications of tahes rather than neuritis, — an affection of the sphincters ; a sense of constriction round the trunk (which may be felt over a wide area as a band rather than as a cord) ; and lastly (but among the first in importance), the reflex action of the pupil to light is often lost — seldom if ever in neuritis. Since it may be normal in tabes, its loss is of more significance than its presence, but the cases of tabes in which it is preserved form only a small minority, so that its preservation is often at least corroborative evidence that the case is one of polyneuritis. Mental change is of little value in the diagnosis unless it is in the form of definite delirium ; but the less common symptoms of tabes, if present, often afford proof of the nature of the malady, although generally in association with other symptoms rather than by themselves. Optic nerve atrophy, for instance, is almost unknown in the neuritic " pseudo-tabes," and so also are the various "crises:" care must betaken not to confound the vomitiu'^y of alcoholic gastric disturbance with the gastric crises of tabes. The trophic changes differ in the two : the tabetic enlargement of the bones and disease of the joints are unknown in neuritis ; and so, in the former affection, are the simple arthritic adhesions and the " glossy skin " of the latter. If all the symptoms are considered separately for their individual value, and conjointly for their associated significance, it is not often that the observer will remain in doubt. One other special diagnosis should be mentioned, that for hysterical palsy. This occurs chiefly in women when the symptoms are motor and are in the legs. When in the arms, the characteristic situation of the palsy usually attracts attention and prevents error. A defect in the power of extension of the wrist has probably never been met with as a consequence of hysteria. Slight ataxy may, however, be purely functional in nature, but the knee-jerk is not lost, and if there is anaesthesia it is much more extensive in the functional affection. It is of great importance to know whether the spinal cord is suffer- in o- as well as the nerves. The following symptoms are those that are the most common and important evidence of this complication : — (1) Any impairment of the functions of the bladder or rectum — inconti- nence of faeces, retention or incontinence of urine. It is not, indeed, improbable that their impairment may form part of the most intense ' form of polyneuritis, but it is not part of the ordinary phenomena of the disease ; hence, in such cases, these symptoms suggest that the disease involves the cord as well as the nerves. It is important to re- member that when there is mental change, evacuations into the bed are frequently without significance as to the state of the sphincters, and are due solely to the inertia of the mind. This is a fertile source of error. (2) A distinct sense of constriction, " girdle-pain," referred to any part of the trunk, probably always constitutes proof of damage to the cord. Of the same significance is sharp pain radiating around the trunk at a definite level and not elsewhere. (3) An important distinction in alcohohc cases is an unusual distribution of the affeo- DIAGNOSIS. 177 tion, e. g. complete paralysis of all parts of tlie legs, or weakness of the muscles above the knee, and not of those below. Impairment of sensation up to a certain level on the legs or trunk has the same sig- nificance ; disease of the nerves does not involve those of sensation up to a definite level. Bedsores also increase the probability that the cord is affected. If a case is recognised as one of multiple neuritis there remains the question, what is its cause ? In many cases this question does not arise, because the cause is obtrusive, and has been recognised as one of the elements of the diagnosis ; but in other cases the cause is not clear, the diagnosis has been made independently of it, and it remains to be discovered. For the most part it is only necessary to know the various causes in order to determine which is effective in the patient under observation, because one or another of them is to be discovered without difficulty, and the rest are absent. It may be useful, however, to remember that, as a rule, in chronic metallic poisoning the arms suffer before the legs, and that in lead poisoning the acute paralysis is limited to the arms ; in arsenical poisoning the affection of the arms is soon followed by that of the legs, while in alcoholic cases the legs generally suffer first. In a case in which arms and legs are affected simultaneously metallic poisoning woxdd be a very unlikely cause. An initial affection of the proximal parts of the limbs at the same time as the distal parts suggests some other cause than alcohol, especially cold or toxaemia. Early affection of the muscles of the trunk or of the bulbar nerves has the same significance, and so also has severe con- stitutional disturbance at the outset. It must be also remembered, however, that alcoholism often co-operates with other causes, especially with cold ; and it must also be remembered that the inquiry needs to be exhaustive before the influence of alcohol can be excluded. This is especially true in the case of females, who often obstinately deny that which would bring shame upon them. Exposure to cold has generally been severe ; and if it has not, the co-operation of alcohol is extremely probable. Neuralgic pains of irregular distribution in addition to the symptoms of polyneuritis should suggest diabetes as a cause, but the examination of the urine for sugar should never be omitted. "When polyneuritis is due to septicaemia this cause may be suggested by the fact that the patient is under treatment for some surgical ailment ; while in all cases of obscure origin inquiry should be made for any acute specific disease to which the neuritis is known to be secondary, and the fact should be remembered that a considerable interval may separate the two. Some form of toxaemia is always suggested by the fact that the onset of the neuritis is associated with such pyrexia and constitutional disturbance as indicate an acute morbid blood- state. But this diagnosis often rests chiefly on the exclusion of other causes ; if these are absent, the fact that neuritis is known to result from obscure blood-poisons may be allowed weight, especially if the symptoms begin in the legs or in aU parts of the limbs simultaneously, and do not affect VOL. I. 12 178 MULTIPLE NEURITIS. exclusively at first tlie extensors of the extremities. Sensory symptoms in these cases at the early stage often take the form of tingling and " numbness," and the pains so characteristic of the alcoholic form are frequently absent, or are represented only by dull aching. In slight cases of this type sensations of numbness and " pins and needles " in the legs, "with readiness of fatigue and loss of the knee-jerk, may be the only symptoms. The facts that the nature of toxaemic causes is to a large extent unknown, and that the poison may probably be acquired from without, make it necessary to be prepared to fi.nd this cause of multiple neixritis under almost any circumstances. Eesidence abroad should suggest an inquiry for exposure to malarial influences. The possible significance of tubercle as a cause should lead to a careful exa- mination of the lungs ; but the possibility that phthisis may be an effect, and not a cause, of multiple neuritis must be borne in mind. Prognosis. — The danger to life is in proportion to the acuteness of the malady, to its severity as measured by the extent of the para- lysis, and to the degree in which the strength of the patient is impaired by other maladies, or by the cause of the neuritis. It is important also to remember that when the affection has increased up to the time that the patient comes under treatment, it generally does not respond immediately to the arrest of its cause, such as the with- drawal of alcohol, but continues to increase for two or three weeks. It is this temporary progressive tendency that constitutes the graver element in the disease, and must be taken into account in every initial prognosis. Hence the forecast must be guarded in all cases that are severe when the patient comes under treatment, and most so if there has been a rapid increase in symptoms that had existed for a long time in slight degree. If the extensors of hands and feet are powerless, and the muscles connecting the limbs with the trunk are distinctly enfeebled, unless the disease has clearly begun to lessen, there is danger that a further extension may involve the muscles of respiration; this is especially great when the muscles moving the shoulder are considerably weakened. It obviously follows that the danger is still greater if the muscles of the trunk, and especially of the chest, have already given evidence of changes in their nerves. Pain in the trunk of the same character as that in the limbs is also a grave symptom if the motor power of the limbs has become small, or the case is one unusually general in its distribution, because where the sensory fibres are suffering the motor fibres are in danger also. Paralysis of the diaphragm adds considerably to the danger, and its power should be carefully watched in the manner and with the precautions mentioned in the account of its paralysis (p. 33). It may become paralysed without the fact coming to the conscious- ness of a patient lying quietly in bed, but a slight weakness of the intercostals wUl then cause considerable difficulty of breathing and an accumulation of mucus in the lungs, a condition predisposing to definite bronchitis, by which the patient may be quickly suffocated. PUOGNOSIS. 179 The importance of this point is great, since respiratory palsy is one of the most common immediate causes of death. It is probable also that deficient breathing power is one of the causes, perhaps even the chief cause, that lead to the development of the chronic phthisical lung disease that comes on in so many prolonged cases. Especially important, also, is any indication that the nerves of the heart are suffering. In an acute increase due to continued use of alcohol the vagus sometimes suffers severely before other nerves, and increasing frequency of the pulse is then of most serious significance. The prognosis should be guided by the motor rather than by the sensory symptoms. The latter may improve while the former increase with- out lessening the gravity of the latter indication. Persistent oedema is of bad omen, and so also are other indications of considerable blood- change. When once the malady has become stationary, and its cause has definitely ceased, the danger to life is small, except in severe cases, in which the pains are intense, the patient helpless, or the heart is feeble, and the pulse persistently frequent, or there are signs of lung disease. In these, as in all cases, moreover, the danger is much increased by any indication that the spinal cord is involved. The tendency to re- covery is far less in the cord than in the nerves ; and retention of urine (with all its secondary consequences), bedsores, &c., are prone to occur, and to involve their own danger even if the disease in the cord does not increase. The prognosis as regards life in cases of moderate severity depends, indeed, as much on complications as on the state of the nerves. Signs of chronic cerebral meningitis, of degeneration of the walls of the heart, of disease of the liver and of the kidneys, also lessen the prospect of escape with life. The danger is, however, greatest, and the mortality highest, in the acute cases that are due to some toxsemic state or to cold, and it must be estimated by the rapidity with which the paralysis develops and spreads. Whenever it becomes considerable in a few days, the danger of early extension to the mechanism for respiration is very great. In these cases, also, pneumonia frequently occurs, concomitant with the early sjrmptoms, and few cases thus complicated recover. In cases that are not fatal the full development of the symptoms is followed by a stationary period, which lasts for one or two months before improvement begins, and for this the patient or friends should be prepared. The course of restoration is always extremely slow ; the muscles least affected regain power in from two to four months, but it is usually six months or more from the onset of improvement before the . extensors are fairly strong, if their palsy was considerable or complete. The intrinsic muscles of the hand are still longer in recovery. The improvement in the nutrition of the muscles follows that in their power, so that they remain smaller than normal, long after they have regained strength. It may, indeed, be years before the muscles whose size can be well seen, such as the abductor indicis, are of normal size. 180 MULTIPLE NEQRITIS, It is seldom that any peimanent weakaess is left unless tlie spinal cord is diseased, and when a patient is distinctly improving a good ultimate prognosis may be given, provided there are no complications to inter- fere with it. In no case with distinct spinal symptoms can we feel confident that restoration of power wUl be complete ; and in cases in which there are indications of considerable damage to the cord it is almost certain that some lasting weakness will be left. The electric irritability of the muscles and nerves may be expected to return to the normal more slowly than their capacity of response to the will, but sooner than their nutrition. The conditions that are ob- served in these cases are the same as in the isolated form of neuritis, in which, although the primary change is in the connective tissue, the symptoms depend on the secondary changes in the nerve-fibres. Hence the statements made on p. 71 are equally apphcable to multiple neuritis. The reactions often furnish important information, especially soon after the onset ; the more the irritability deviates from the normal the greater will be the subsequent wasting, and the longer the duration of the palsy. When some faradic irritabihty returns in both nerve and muscle it may be regarded as a sure indication of advancing restoration of structure, which is certain to involve a progressive in- crease of conduction of voluntary impulse, and response to it. If the trunk nerves are not involved, the prognosis in severe cases is a little better when the arms are chiefly affected than when the legs have suffered most. The sensory disturbance may be expected to follow a course on the whole similar to that of the motor symptoms. A diminution in the spontaneous pain may be anticipated sooner than in the tenderness of the nerves and muscles, which usually lasts, in lessening degree, until the muscles have regained some power. The extreme tenderness, indeed, passes away with the spontaneous pain, but some degree of over- sensitiveness continues for a long time. Happily the tendency to persistent neuralgia, seen after the isolated form, need not be antici- pated after multiple neuritis. We find the explanation of this in the absence of the new formation of connective tissue from the inflamma- tory products, which in the isolated form perpetuate, by cicatricial con- traction, the irritation to which inflammation gave rise. There is little dift'erence in the prognosis, as regards recovery, in the different forms of neuritis. The anticipations that may be formed are governed in all by the rules just mentioned, and the risk to life has been already considered. In aU, however, it may be repeated the extent to which the cause is under control forms an essential element in the problem, and must influence the conclusion in every case. The prognosis, however, is better in the sensory than in the motor form, better when the arms escape than when all the limbs are involved, and better in cases of chronic than of acute onset, and better if an apparently acute onset is really such than if it succeeds slight sym- ptoms of longer duration. When the malady follows an acute specific TRRATMENT. 181 disease, the severity of the latter is no guide to the course of its sequel ; severe neuritis may follow a mild attack of the acute specific. Treatment. — The different classes of multiple neuritis here con- si.ho could not have been infected within ten years of the first sym- ptoms. In one case of infection from adult to adult, nine years elapsed after the death of the leper before the man who had lived with him began to suffer. When, indeed, a large quantity of the virus is received, the malady develops much more rapidly. But leprosy differs from beri-beri, and from most other forms of multiple neuritis, in the fact that although inflammation of many nerves is frequently a part of the disease, it is not an essential part or a constant feature of the affection. On the contrary, it is only one of an extensive series of lesions, inconstant, not only in its occur- rence, but in its seat and extent. It characterises a special variety Df the disease, the "anaesthetic leprosy," in which not only areas of the skin become insensitive, but the ends of the fingers may suffer such an impairment of their nutrition that they are lost. Moreover, LEPKOUS NEUiaTIS. 193 as we have seen in the introductory section, the want of strict sym- metry is associated with an important difference from the symmetrical forms — the neuritis is not a parenchymatous or degenerative form, but is a periaeuritis and interstitial neuritis, and the damage to the fibres is secondary. This change in the connective tissue is asso- ciated with the actual presence of the organisms in it. The neuritis thus seems to be due to the direct action of the bacilli on the affected tissues, and not, as in beri-beri, to a virus circulating in the blood — not to a product of the organisms, but to the organisms themselves. This fact enables us to understand better its peculiar features, and especially its irregular distribution; the inflammation occurs where the organisms happen to fix themselves in the connective tissue, and although certain common conditions on the two sides may determine a partial correspondence in the nerves affected, there is not the sym- metry that results from an action on like structures on the two sides, equally accessible to the virus. In this, and in its connective-tissue seat, the neuritis of leprosy resembles more the isolated neuritis of syphilis, rather than the common varieties of the multiple form.* The symptoms of the malady are extensive and various, but only those that consist in derangement of the functions of the nervous system concern us here, and it is alike needless and impracticable to describe the others. The nervous symptoms of leprosy depend almost exclusively on inflammation of the nerves. These symptoms are muscular wasting and ansesthesia, greatest in degree towards the ex- tremities of the limbs, but more or less irregular in situation, and in the region of the distribution of nerve-trunks, which, if accessible, are obviously diseased. The symptoms are not confined to the limbs, but are also met with in the face, where an affection of the fifth nerve may cause ansesthesia, and movement may suffer from involvement of the trunk of the facial nerve, so that the eyelids cannot be completely closed. The form of sensibility that is impaired also varies ; sometimes touch, sometimes pain is lessened in greater degree, but usually all forms are implicated to some extent. The legs often suffer before the arms, but a special order of affection cannot be distiaguished. There may be unpleasant tiagling sensations, but pains are usually trifling, perhaps because the process is extremely chi-onic. In some cases there may be severe pain in the position of the nerves or deeply seated in the limbs. The inequality of the affection of the fibres of the same nerve is shown by the fact that the knee-jerk may persist although the extensors of the knee are partially paralysed. Fig. 62 shows the distribution of anaesthesia in the hands in a well-marked example of this disease which came under my observation some years ago. The patient was a Creole of Mauritius, who had come to England in early childhood, and presented the first distinct symptoms at * Gerlacb (• Virch. Arch.,' cxxv, *Neur. Cent.,' 1891, p. 464) says infection is from skin, branches of nerves being then affected and finally the nerve-trunks, so that skin may be seen infiltrated when nerves still remain free. VOL. I. 13 194 MULTIPLE NEUEITIS. twelve years of age — changes in fhe pigmentation of tlie skin, auses- thesia, and muscular wasting. They steadily increased during the next four years, the anaesthesia extending each half-year from one finger to another. There was also patchy anaesthesia of the legs below the knee. As the figure shows, the loss of sensation does not correspond in area to nerve distribution. This depends on the fact that even when all the nerves, in- PlQ-. 62. — Distribution of anaesthesia in a case of leprosy. The black areas indicate the loss. eluding those of the fingers, are diseased, all the fibres may not be destroyed in any one nerve, so that some sensibility exists in each nerve area. Various perversions of sensibility, spon- taneous " dyssesthesise," ting- ling, formication, and the like, may precede the loss. The latter usually occurs gradually, but sometimes so suddenly as to suggest some secondary vascular lesion, haemorrhage or thrombosis, in the vessels of the nerve that is the seat of the process — a possible result in its early and most active stage. It must be remembered that in all inflammations of the sheath and interstitial tissues this proceeds to a considerable degree before the fibres of the nerve suffer, and thus sudden loss of sensibility does not show that the nerve was previously healthy. This occasionally sudden onset is of much practical importance ; one case was sent to me from a place in which the disease is endemic, by a doctor well acquainted with it, who had not suspected leprosy because the anaesthesia came on almost suddenly. Accompanying anaesthesia there is usually some muscular wasting, which may be great. In the case figured it was considerable, although only in the small muscles of the hands was it comparable to that of progressive muscular atrophy. The electrical excitabihty of the mus- cles was greatly lowered to each current, and this is perhaps the most common condition ; either the damage to the nerves is so chronic that the fibres undergo slow changes paH passu with those in the nerves and their endings, or the patient comes under observation at a late stage in the local affection, at which the changes present in the early stage Tiave disappeared; sometimes, indeed, all irritability has vanished. In cases that are seen soon after the onset of the lesion of the nerves, there may be the reaction of degeneration in the muscles, either partiaJ LEPEOUS NEUMTIS. 195 or complete, and there is often a conspicuous exaltation of the mechanical irritability of the nerve-trunks. When the facial nerves are affected this may be well seen, and may resemble that met with in tetany.* The thickening of the nerve may be felt when that which is affected is accessible. The state of myotatic irritabihty varies accord- ing to the distribution of the neuritis ; it is lost at places where the sensory or motor fibres are involved, but those supplying the front of the thigh and its muscles often escape, and the knee-jerk is preserved. Anchylosis of the joints may occur, as in other forms of neuritis. The " mutilations " of leprosy, by which the ends of the fingers and toes are lost, are also regarded by some as a consequence of the neuritis. The nume- rous other symptoms of the disease are indepen- dent of the nerves (except perhaps the pigmentation of the skin), and are be- yond the province of this book. The neuritis of leprosy is typically adventitial (Fig. 63). The primary sheath and the secondary- sheaths of the fasciculi are greatly increased in thickness, and consist of nucleated fibrous tissue arranged concentrically (a, b). From the sheath, tracts extend into the in- terior of each fasciculus (b), isolating the groups of nerve-fibres. The in- crease of tissue even ex- tends between the fibres themselves (c), and these undergo slow wasting ; many of the fibres in the figxire are seen to be distinctly narrower than normal. The concentric growth of fibrous tissue may even invade the whole area of the fasci- culus, all the nerve-fibres perishing before it (d). The characteristic bacillus of leprosy is found abundantly, in recent cases, in the new tissue of the nerves. Peculiar cells are met with, infiltrated with the B~ Pia. 63. — Sections of nerves from a case of anaes- thetic leprosy, under the care of Dr. Buzzard. A, median nerve at wrist x 5; B, portion of same more highly magnified; c, part of a less diseased fasciculus from the ulnar nerve; D, a small fasciculus from median in which the con- centric fibres have invaded the whole area of the fasciculus. * Schultze, 'Deut. Arch, f.kl a. Med.,' 1888, Bd. xliii. 196 MULTIPLE NEURITIS. organisms. As tlie fibrous tissue develops and contracts, tlie bacilli seem to perish, and ultimately can no longer be discovered. The diagnosis depends on the occurrence of irregular areas of anaes- thesia, generally associated with irregular patches of pigmentation and pallor in the skin, and often with muscular atrophy, in a person who has been exposed to the risk of infection, generally by having lived in a district in which the disease is endemic. The irregularity of distribution and the limitation of considerable sensory changes sufficiently distinguish it from other forms of neuritis. The spinal affections with which the mixed anaesthesia and wasting are most likely to be confounded are, as Schultze has pointed out, cases of syringomyelia in which the distension of the central cavity damages the grey matter, and may cause similar symptoms of irregular distri- bution — muscular atrophy, sensory impairment, trophic disturbance.* But these are limited to the arms ; and if the legs suffer it is in a different way — as simple paraplegia with excess of myotatic irritability that may go on to spasm. The prognosis of the disease in the simple anaesthetic form is grave only when the sufferer is still exposed to fresh infection, or in cases of considerable severity. But it must be remembered that, just as the disease may develop long after exposure to its cause, so it may slowly increase for a long time after this exposure has ceased. The treatment of the affection is beyond the scope of this work ; in so far as the nerve symptoms require special measures, these are the same as in ordinary neuritis. A trial may be made of the stimula- tion of the muscles by whatever form of electricity they will respond to, and of the anaesthetic areas in the skin by the wire brush and faradism. HERPETIC NETJEITIS. Among the cutaneous eruptions occurring in acute neuritis, that which characterises "herpes zoster" has been mentioned. This affec- tion always presents a correspondence in area with nerve distribution ; a definite neuritis has been found in the rare cases which have afforded an opportunity for pathological investigation; and pain with other nerve symptoms is common, and may be conspicuous. Hence herpes, although usually described as a skin disease, is really the manifestation of a form of neuritis which is sufficiently individual in course and features to merit a separate description.f Causes. — Our knowledge as to the aetiology of the neuritis which underlies the most common form of herpes is still very incomplete. An important clue is, however, afforded by the fact, first pointed out by Mr. Jonathan Hutchinson, that the disease may be induced by the • See " Mor\ an's Disease," later. f The first suggestion as to the neivous origin of herpes seemB to have been made by Richard Bright, 'Reports of Medical Cases,' 1831, vol. ii, part 1. HERPETIC NEUEITIS. 197 presence of arsenic in the blood. This indicates that it may be due to a chemical toxic agent in the circulation, and suggests that as its common cause. But the nature of the agent is still quite un- known. The careful researches of Eendu cast doubt upon the setio- logical importance once attributed to gout, although a causal connection cau occasionally be traced, as in a well-known case of Trousseau's. Ebstein * records the case of two brothers who, after eating mussels, developed the one urticaria, the other herpes. The affection has been traced to malaria by Winfield.f We know, furthermore, that some of the many varieties of rheumatic toxins may act upon various parts of the nervous system, in a manner not unlike that seen in poisoning by arsenic, so far as concerns the characters of the nerve inflammation. Herpetic neuritis may thus probably be produced by toxins introduced from without, or manufactured within the body ; it may even assume an epidemic form. We do not know why it should usually be unilateral a.nd show a predilection for certain regions ; the reason is probably a local one, and it may be noted that herpes has been seen to develop in the scar of a burn, and to reappear in those left by a first attack forty-six years previously. Neither age nor sex seems to have much influence in relation to the disease. Pathological Anatomy. — The indications of inflammation have been found especially in the ganglia on the posterior spinal roots ; they tend to spread centrally towards the cord, rather than peripherally. The Gasseiian ganglion, which corresponds to that of a posterior root, is similarly affected in herpes frontaHs. Although these inflammatory changes were first described (by von Barensprung) as long ago as in 1861, our knowledge as to their exact nature is still meagre. We can state, however, that they affect primarily the intercellular material, and that they are ordinarily very severe, frequently inducing hsemor- rhagic exudation ; the swelling and injection of the ganglia and adjacent nerve-trunks are usually macroscopically evident. We must distinguish from this primary form those in which the eruption is only a conspicuous symptom of inflammation communicated to the nerve, or clearly secondary to some other cause. Thus Wagner records in one case purulent pachymeningitis and swelling of the spinal gangha of the affected area. The occurrence of bilateral herpes is explained by Kaposi J on the ground of primary affection of the spinal cord, but no anatomical proof of this is adduced, and it seems more reasonable to look to the general action of the toxic agent in the blood as the cause. As to the nature of this agent we are, except in the case of the special poisons already mentioned, absolutely ignorant. This point has already been discussed in connection with neuritis. With regard to distribution, although practically any sensory nerve * ' Vircliow's Archiv,' vol. cxxxix. t ' New York Med. Journ.,' 1895. J Euleiiberg's ' Real Eacyklopadie,' art. " Herpeg." 198 MULTIPLE NEURITIS. may stiffer, the main incidence is upon the intercostals, and particu- larly those of the lower dorsal region ; the fifth nerve, in any of its branches, but particularly the first and second, and the branches of the cervical plexus, giving rise to the occipito-cervical form, the small occipital and great auricular nerves being most affected. The lower part of the leg is an occasional seat ; the arm very seldom suffers. The inflammatory process may spread to the adjacent motor nerves (see later), or into the spinal cord, leading in one case to death from ascending myelitis.* The herpes itself is commonly ascribed to im- plication of trophic nerves, but Ebstein (loc. cit.) regards it as due to inflammatory irritation of the vaso-dilator fibres. Symptoms. — The description of the herpetic eruption falls properly within the province of dermatology. Areas of congestion appear with oedema passing on into inflammation with effusion ; the epi- dermis is raised, and pus may ultimately form. The conspicuous commencement in certain foci is probably to be referred to the affection of terminal nerve divisions, or their corresponding ganglionic cells. It is significant of a general toxic cause that the attack may be ushered in by gastric prodromata, particularly vomiting, with con- comitant fever. Of the neuritic symptoms the most conspicuous is pain, which will be more fully considered under the head of neuralgia ; it vsdll here suffice to note the distinctions between the pre- and post- herpetic pains, the former of which usually abates with the appearance of the rash, while the latter is both more severe and of longer duration. Either aneesthesia or hypersesthesia of the region served by the affected nerve frequently follows the eruption ; there is in some cases per- sistent interference with conduction. Motor affections are also not uncommon. These may be simply immobihty from hypersesthesia or true paralysis from spreading of the neuritis to motor nerves. In the latter case there is some muscular atrophy with more or less perfect reaction of degeneration. Ebstein has collected twenty cases of herpetic palsy, of which at least two were simply hyperaesthetic immobility; in three of the others the paralysis preceded the erup- tion. The facial nerve is the one which most commonly suffers, and its palsy may supervene upon herpes of the trigeminal or occipito- cervical type. In a case recorded by Lesser, frontal herpes was succeeded by paralysis of the fourth cranial nerve, the inflammation having, it is suggested, spread from one nerve to the other in the ftavemous sinus. As regards prognosis, aU that need be said is that the severity and persistence of the neuritis usually vary directly with the age of the patient. The question of the treatment of herpes does not fall within the scope of this book ; it may, however, be mentioned that the pain is frequently alleviated by galvanism, failing which cocaine may be tried. * Hardy, ' Qaz. des Hopitaux,' 1876. PABT Til. DISEASES OF THE SPINAL CORD. INTRODUCTION. ANATOMY OF TEE SPINAL CORD* The spinal cord, it will be remembered, is mucli shorter tLan the spinal canal, reaching only to the second lumbar vertebra. Hence the nerve-roots descend to their foramina of exit. The lower they arise, the longer is their intra-spinal course. All those below the second lumbar pair leave the canal below the lowest portion of the cord. It is customary to speak of the portion of the spinal cord from which each pair of nerves arise as the corresponding " segment" of the cord. The segments are longest in the dorsal region, and shortest in the Imnbar enlargement. They are also called " metameres." The only parts of the spinal column that we can usually feel are the vertebral spines. Mauy of these are not on a level with the bodies of their vertebrae. It is important, therefore, to know the relation of the spines to the bodies of the several vertebrae, and of these to the origin of the nerves. These relations are shown in the accompanying figure (Fig. 64) . Of the Membranes, the pia mater closely invests the surface, and is continuous with the tracts of connective tissue that pass within the substance of the spinal cord. It is also prolonged along the nerve- roots as their sheaths. The arachnoid forms a much less close invest- ment. The dura mater is not in contact with the bones as it is in the cranium, but a layer of fat and a plexus of large veins intei-vene * The following outline of the anatomy of the spinal cord is intended merely to place before the reader those points that are essential, or likely to become so, for understanding the functions of the organ and the symptoms of its disease. It does not profess to be exhaustive even in outline, and is designedly kept as free as possible from whatever, in either the substance or terminology of recent science, does not come within the scope of those objects. Many of the results reached by modern investigators are mutually incompatible, and where a choice has been necessary the observers have been followed who possess the greatest authority and whose conclusions best agree with facts previously ascertained. 200 SPINAL OORD. a between the two. It thus forms a loose sheath for the cord, and variations in the amount of blood in the plexuses outside it permit corresponding (but inverse) varia- tions of the amount of cerebro-spinal fluid within it. An extension of the ' ^ dura mater passes along each nerve-root, CI 0^^^^^ . " and blends with its sheath. Structure of the Spinal Cord. — The general form of the cord, the enlarge- ments it presents, and its constitution of white and grey substance, are too well known to need description here. The wJiite substance surrounds the grey, ex- ^ ' (^..^'^SU-^-^-)- 1 D cept at the two points at which the 2 posterior horns come to the surface (Fig. 65). It consists of meduUated nerve-fibres, chiefly longitudinal. The posterior cornua isolate the posterior ^ columns from the rest of the white sub- 8 stance. These columns are separated by 7 a " posterior median septum " of connec- tive tissue, and a little distance from this another incomplete septum, " posterior 9 intermediate septum," corresponding to jg a depression on the surface, marks off 10 i^/r'^^JfTf I 3- portion next the median septum, the ^1 2'^=^'"" " ^^ " postero-median column," or " column f^l^lStr'^" ' "'"'" ^^ °^ GroU," from the part next the pos- "^ terior horn, " postero-external column," Fia. 64. — Diagram (framed from an original in- — . - 3 vestigation) showing the relation of the verte- bral spines to their bodies and to the origin of g the several nerve-roots. It will be seen that .-'iijllj m the ends of the vertebral spines are opposite C-^/lll \ ^ I *^® middle of their own bodies only in the — ^ lumbar region; they correspond to the lower edge of their own bodies in the cervical and ■"" ° the first two dorsal vertebrsfi, and to the upper part of the body below in the rest of the dorsal j s region. Each cervical spine is nearly opposite the lower roots of the nerve below; the vertebra 2 prominens is opposite the first dorsal roots, nnd from the 3rd to the 10th dorsal the spines correspond to the second root below; the 11th 4 spine corresponds to the 1st and 2nd lumbal nerves, the 12th to the 3rd, 4tl), and 5th ; the ■"' ■ ^ 1st lumbar to the 1st, 2nd, and 3rd sacral 0° nerves, while the tip of the cord is opposite the upper part of the 2nd lumbar. or "column of Burdach," the part of which next the cornu is caUed the "posterior root-zone," because many fibres of the STBUOTUKE. 201 posterior root pass through it. The rest of the white substance is diyided, in the middle line in front, by the anterior median fissm-e, Fiff. 65. — Diaeram of a section of the spinal cord in the cervinal region. A.. C, anterior commissure; P. C, posterior commissure; I. g. s., intermediate grey sub- stance; p. Cor., posterior cornu; c. c. p., caput eorna posterioris; L. L. L., lateral limitinsr layer; a.-l. a. t., antero-lateral ascending tract, which extends along the periphery of the cord. down which the pia mater a.nd blood-vessels pass, and at the bottom of which is the anterior or white commissure. Between the anterior median fissure and the posterior cornu the white substance is con- tinuous and undivided, extending round the front and side of the cord. It is artificially divided into an anterior and a lateral column, the line of division being the outermost of the anterior nerve-roots, which pass through the front of the cord ; but there is no corre- sponding distinction of structure, and hence it is often termed the ** antero-lateral column." The white substance varies in amount in different parts of the cord, but, as a whole, lessens gradually from above downwards (see Fig. 66). It is everywhere composed of niedullated nerve-fi.bres, which, however, possess no neurilemma-sheath. In carmine- stained sections the axis-cylinder is seen within each fibre, not always in the centre, and around this are concentric cloudy lines due to the irregular refraction of the white substance. Between the fibres is a peculiar substance, the " neuroglia,*' or nerve-cement. It appears to consist of nucleated branched cells ("spider-cells"), whose long, delicate processes form the fibres of the neuroglia. The cells, stellate on section, are found in the larger interspaces between the nerve-fibres. The fibres of the neuroglia branch and interlace, forming a very fijie network; some of them 202 SPINAL COED. are arranged radially; starting centrally from the outer ends of the ciliated epithelial cells which line the cerebro- spinal canal, they diverge, branching as they go towards the surface of the cord. This neuroglia is developed from the same (epithelial) embryo- logical elements as the nerve- structures — an important fact, because it enables us to under- stand the fact that, in defective development of the nerve- struc- tures, the neuroglial tissue is ex- cessive in amount. But its differ- entiation in development involves also its chemical nature, since it contains far more of a material like that of hair or horn, and hence called " neurokeratin." The nerve-fibres, thus con- nected, lie in a coarser network, formed by branching processes of septa that proceed inwards from the pia mater. In these septa blood-vessels run, and some are occupied by nerve-fibres that have a horizontal course. The septa consist of fine fibres of ordinary connective tissue from the pia mater, and of neuroglial material, which forms also a layer between the membrane and the nerve-fibres in the intervals be- tween the septa. This layer varies considerably in thickness. Many of the septa pass through the white substance to join projec- tions from the grey substance, which cause the irregularity of the outline of the latter. These processes, outside the neck of the posterior cornu, are broad, and join each other so as to form a sort of network, the meshes of which en- close columns of nerve-fibres. This is called the " lateral reticular f or- Fia. 66.— Diagram showing the relative mation " (Fig. 65, right side ; also size and shape of the cord and orey „^ „ on rm ^ j. i? j.i matter at diaWit levels. 66, c 2—8). The substance of the^ STRUCTURE. 203 horn behind the caput is sometimes broken up in the same way— the " posterior reticular formation." The grey substance varies in shape and size in different parts of the cord, being largest in the cervical and lumbar swellings, and corre- sponding to the number and size of the nerve-roots given off. The variations in shape and size are indicated in the accompanying figure (JoQ), and will be readily understood by an examination of this. The division into anterior and posterior horns or cornua is familiar. The part on each side that intervenes between the two horns may be conveniently termed the " intermediate grey substance '•' (I. g. s. in Fig. 65). In the dorsal region a projection from this extends into the lateral column (Fig. Q&, d 2, 5, and 8), and has been termed the "lateral horn"). It is customary to divide the grey matter into two varieties, "spongy" and "gelatinous." The latter forms a cap on the posterior horn, and a layer immediately around the central canal, and is named on account of its naked-eye aspect. It consists largely of neuroglia, traversed, however, by nerve- fibres, and with numerous nerve-cells scattered through it. The spongy substance, which forms the rest of the two cornua, consists mainly of an exces- sively fine f elty network of very narrow meduUated nerve-fibres, naked axis-cylinders, and fine nerve-fibrillse which arise, in part at least, from the dendrites of the nerve-cells, and in part by a division of the axis-cylinders of the nerve-fibres. These structures are em- bedded in a supporting neuroglia. Through it course many larger medullated nerve-fibres, passing to or from the white columns and nerve-roots. In it also lie many nerve-cells of various sizes. Those in the anterior cornu are, for the most part, large " ganglion-cells ; " each contains a large nucleus, and usually a mass of pigment, and Fig. 67. Fia. 68. Fia. 69. Fig-. 67. — A nerve-cell from tlie anterior cornu of the spinal cord of man: a, uubranched process becoming the axis-cylinder of a nerve-fibre; b, pigment mass. (After Gerlach.) Fig-. 68. — Nerve-cells of the anterior cornu sending a pro- cess into tl e anterior root. (After Henle.) Fig. 69. — A fine nerve-fihre dividiii'i' into two parts, each of whiih joins the plexus of fibrillse formed by the branching processes of a nerve-cell. From the spinal cord of au ox. Gerlach.) (After 204 SPINAL CORD. sends out several processes. One process, the axon, is continuous with the axis-cylinder of a nerve-fibre (Fig. &?), and can be sometimes traced into a fibre of an anterior root (Fig. 68). The other processes, or dendrons, after a longer or shorter course divide and subdivide, their ramifications ending in minute knobs in the sponge-like matrix of the grey substance. In this they are probably brought into close contiguity with the terminal ramifications of other neurons (Fig. 69) . These cells lie in groups, between and through which course tracts of fibres, chiefly from the anterior roots. Other fibres come from the anterior commissure, white columns, and posterior horn. The axons of these cells are certainly motor in nature, and become the motor fibres of the spinal nerves. Similar cells are also found in varying numbers at the anterior periphery of the cord, and even among the fibres of the already descending anterior roots.* Birge, in a careful investigation, found that in each segment of the spinal cord of the frog the number of nerve-cells in the anterior cornu nearly corresponds to the number of fibres of the anterior roots arising from that segment. Each ceU is traversed by many nerve-fibrillse, such as are discerned in a cell-process or in the axis-cylinder of a nerve-fibre. These cross and intermingle in the middle of the cell, but pass along the margin from one process to another. By this arrangement impulses entering the cell by one process may leave it by many.f The arrangement of the nerve-cells of the anterior cornu is of some practical importance, on account of the frequency with which this part is the seat of limited lesions. They form, as already stated, certain groups, but these groups vary in different regions of the cord, partly under the influence of the shape of the horn, partly irrespective of this ; and they even vary in parts of the cord that are near together. They are influenced by the course of the tracts of fibres of the ante- rior roots, which may pa,ss through a group and break it up into smaller groups, although in a neighbouring section it is undivided (see Fig. 70, the cervical groups). Hence very different descriptions have been given of these groups, and the process of distinction has sometimes been carried too far. The groups that can most readily be recognised are the following : — In the inner anterior angle of the cornu is a small group, the inner or median group. This is one of the smallest, and is absent in some parts of the cord, especially in the lumbar region. A much larger group lies near the anterior edge of the horn, in the * Hoche, 'Neurol. Cenfcralbl.,' 1891. t Kronthal, * Neur. Centralbl.,' 1890, p. 40. Impulses may thus be difFused, even if there is no junction of fibrillsB or passage of impulses from one fibril to another. This arrangement provides a mechanism by which the nerve-cells maj' conduct and diffuse impulses, but such a mechanism does not exclude (as has been assumed) the reinforcement or origination of such impulses, and their discovery leaves untouched the facts which demonstrate the trophic influence of the cells, and the manner in which they arrest secondary degeneration. These functions are indicated by facts of a totally different nature. Kronthal's observations are of great importance, and appear trustworthy. STRTJCTDHE. 205 middle, or a little to the outer side of the middle, the anterior group. External to this, in the outer extremity of the front part of the horn, is another group, the antero-lateral group. Ihese two groups are often blended, so that the anterior group cannot be separately distin- guished, as in the right-hand mid-cervical figure. A fourth group, usually the largest, Ues in the outermost part of the horn, behind its front, usually in the posterior outer angle ; it may extend inwards, halfway across the horn. It is called the external or postero-lateral grou^f (P.-L., Fig. 70). These three are the most important groups. Upper Dorsal Mid-Lumbar. FlS. 70. — Diagrams of the groups of nerve-cells in the anterior cornu. Groups : — 1., inner or medial ; A., anterior ; a.-l., antero-lateral ; p.-l., postero-lateral ; I. L. p., intermediate lateral process ; p. T. c, posterior vesicular column or tract. The two mid-cervical sections are only a few millimetres apart, and show how the anterior group, separate in the one, may be blended with the antero-lateral group in a neighbouring part of the cord. There is in some parts also a central group, occupying nearly the centre of the horn. In the small cornu of the dorsal region often no weli- defined groups can be made out, but when any can be recognised, they are generally the anterior and external. Similar cells, usually smaller in size and isolated, are scattered through the intermediate grey matter, and a group of cells occupies a projection outwards into the lateral column in the lower cervical and upper dorsal regions. It was termed by Lockhart Clarke the inter- media-lateral tract, but is better designated the intermediate process (or lateral horn), and the cells the intermediate group (i. l. p., Fig. 70). 206 SPINAL CORD. Nerve- cells also lie in the grey matter of the reticular formations, lateral and posterior, and are sometimes described as special groups. Many isolated colls, mediiim and small in size, also lie in the posterior horn. These are probably connected with some of the fibres of the posterior roots. They extend back into the caput comu posterioris.* Throughout the dorsal and in the upper lumbar cord a group of nerve-cells lies in the inner part of the neck of the posterior horn, the posterior vesicular column of Lockhart Clarke (sometimes called "Clarke's column") (p. v. c. Fig. 70; see also Fig. 80). Most of these cells are fusiform in shape, but are placed vertically, so that they appear round or oval in transverse section, and their processes are not seen. Some, however, present processes that run forwards or back- wards. Nerve-fibres pass into and by it, which we shall consider sub- sequently. Although this tract is chiefly developed in the lower dorsal and upper lumbar cord, a few nerve-cells of similar character are met with in the same position in other parts, and are occasionally suffi- ciently numerous to form a small group. The " gelatinous " grey matter, grey substance of Rolando, which forms a cap on the posterior horn, caput comu posterioris (c. c. p.. Pig. 65), differs considerably from the spongy substance. It has been described as made up of granules, but, according to later researches, consists of a peculiar translucent material forming an excessively fine network, which, like the 'rest of the neuroglia, behaves to reagents like horny material. In the embryo it is contiauous with that which surrounds the central canal,t but from this it becomes separated in the course of development. Its basis substance is thus of neuroghal natiire. Numerous nerve-fibres pass through it from the posterior roots, and these, coursing forwards, seem to divide it into columns, as it is viewed in transverse section. A few small ganglion-cells lie in this gelatinous substance, chiefly on the inner side ; it also contains many minute cells, some of which are nerve-cells, while others belong to the neuroglial tissue. From the nerve-cells axons have been traced into the posterior column and horn, the posterior root-zone and the lateral column.J Bundles of vertical fibres are also seen in transverse section, and these are often numerous just above the caput, especially on the inner side of the horn. Most of these are fibres of the posterior nerve-roots that have a vertical course for a short distance. In Fig. 80 the axis- cylinders of these fibres are seen to be changing from the horizontal to the vertical direction, and their relation to the posterior root- fibres can be distinctly traced. The hinder part of the gelatinous • It is generally believed tbat their branching procesBes enter into the plexus of fibrillse in the grey matter, and thus bring these cells into relation with those of the anterior cornua, and also with fibres that cross by the posterior commissure and form the ascending sensory path to the brain. t Cf. Corning, ' Arch. f. mikios. Anat.,' xxxi, 1888. X Starr, ' Atlas of Nerve-cells,' p. 28 ; Leuhossek, • Der feinere Baa des Nerven. systems,' pp. 120 et seq. STRUCTURE. 207 ■ubstance is less dense in structure than tlie rest, and is sometimes distinguislied from it as the " spongy zone."* The gelatinous sub- stance contains many vessels, running for the most part vertically. White Substance. — We may now examine, in greater detail, the con- stitution of the white columns of the cord, and the probable course and function of the fibres they contain. Their analysis has been greatly aided by three facts, — continuity of degeneration, difference in time of development, and the variation in the size of the fibres of the different tracts. 1. It was discovered by Tiirck that in certain tracts in the white substance the nerve-fibres undergo secondary degeneration when separated from their cells of origin, a degeneration analogous to that which, as we have already seen, occurs in the nerve-fibres outside the cord. This mode of investigation has of late acquired a fresh impetus from the new means of staining degenerated nerve-fibres devised by Marchi. 2. In the developing cord the fibres of different tracts acquire their white substance at different periods, and the study of these differences (first by Flechsig and later by Bechterew and others) has not only confirmed, but also extended, the differential indications afforded by disease. It enables us to make a distiaction between fibres that do not degenerate separately, or not through a sufficiently long tract to enable us to distinguish them. The groups into which this method enables us to divide the fibres, and the order in which the meduUation takes place, are as follows : (1) Anterior and posterior root-fibres. (2) -N r inner anterior column. (3) > Ground-fibres of the < postero-external column. (4) J (. outer anterior and lateral column. (6) Lateral limiting layer and antero-lateral ascending tract. (6) Postero-median column. (7) Direct cerebellar tract. (8) Lateral and anterior pyramidal tracts (which in man are first medullated at the time of birth) .f It may be stated as a general rule that the shorter the course of a tract within the central nervous system, the earlier do its fibres acquire their medullary sheaths. 3. The size of the nerve-fibres varies in different tracts, but the full significance of the variations has still to be ascertained. Even in the same tract of the cord considerable variations are met with, which probably correspond with differences in function. "When a tract dege- nerates, it is common for the degeneration to be incomplete ; fibres remain intact among those that perish : this indicates a difference in function, and with it the difference in size usually coincides. It is also possible that some of the small fibres seen among larger ones may be due to the division of the latter (Sherrington) ; but such division • So that in some descriptions the posterior horn is divided into (1) spnngy sub- stance of the horn itself, (2) gelatinous zone of the " caput," and (3) spougy zone at the ti]) of the horn. See Lissauer, ' Ai*ch. f. Psych.,' 1886. t See Obersteiner, loc. cit., p. 192. 208 SPINAL COED. has not been actually demonstrated, and is probably not frequent. The variation in size is from 1 to 25 n (tswo to toVo inch). The variations are especially great in the fibres of the pyramidal tract, and it is in these that division has been thought to occur. Those of the direct cerebellar tract are uniformly large, while most of those that constitute the postero-median column are small. It will facilitate the detailed study of the tracts if we consider first those that undergo secondary degeneration for a considerable distance, as our knowledge regarding these is the most complete. o.a L.4 Fig. 71.— Diagram of the elements of the white substance at various levels of the spinal cord. (Modified from Flechsig.) The pyramidal tracts are shaded by short horizontal lines ; the direct cerebellar tract by dots; the posterior median column by dots, as it degenerates in disease of the lowest part of the cord or of the nerves of the cauda equina % the small circles in the forepart of this column indicate the area which degenerates in disease of the cervical enlargement. The antero-lateral ascending tract ia shown by crosses. The anterior ground-fibres, lateral limiting layer, and postero-external column are left white. Fig. 66 should be compared with this. STEUCTUEB. 209 These degenerations are both ascending and descendiag. Only one important set of fibres degenerates downwards through a considerable extent — those that continue through the cord the anterior pyramids of the medulla. They commence still higher, in the motor region of the cortex of the cerebral hemisphere, passing thence by the " internal capsule " between the two parts of the corpus striatum, &c., to the cms and pons; they are the chief, perhaps the sole conductors of voltmtary impulses. They are termed the pyramidal tracts because they constitute the anterior pyramids of the medulla. They are shaded by short horizontal lines in Fig 71 ; compare also Fig. 65. At the decussation of the pyramids about three quarters of the fibres usually cross to the other side. These pass down the cord in the lateral column, and constitute the lateral (or crossed) pyramidal tract. Those which do not decussate, pass down their own side of the cord, in the inner part of the anterior column, at the side of the anterior median fissure, and constitute the anterior (or direct) pyra- midal tract. Flechsig has found that the decussation is subject to many variations. In the majority of cases the decussating fibres are between 70 and 80 per cent, of the whole. Sometimes they con- stitute a still larger proportion, and in one case (of 60 examined) all the fibres crossed. Sometimes fewer fibres decussate, only one half or even less than half ; in one case 35 per cent., in another only 10. No case has yet been met with in which no fibres crossed.* A con- siderable number of fibres decussate above the medulla, terminating around the cells which give origin to the motor cranial nerves. The lateral pyramidal tract occupies the posterior half of the lateral column, outside the posterior cornu. It extends down to the end of the cord, even when it is originally small. Hence those fibres that do not cross at the medulla must do so lower down in the cord. Through the greater part of the cervical and dorsal regions this lateral tract is separated from the surface by a narrow layer of fibres, the direct cere- bellar tract. In the upper part of the cervical region (third cervical segment) this tract lies farther forwards, so that the pyramidal tract comes up to the surface close to the posterior cornu (Fig. 71, c. 8) ; and here, if the tract is small, there may be a depression on the sur- face. In the lower part of the dorsal cord there is a similar move- ment forwards of the cerebellar tract, so that the pyramidal tract again comes in contact with the surface posteriorly (Fig. 71, d. 12), and, as the cerebellar tract ceases at the first lumbar nerve, the pyra- midal tract extends up to the surface throughout the lumbar enlarge- ment (Fig. 71, L. 4). The inner side of tlie tract is in contact with the hinder part of the posterior cornu, near the surface, throughout the • In the 'Neur. Cent.,* 1898, p. 202, Dr. Philip Zenner describes a case o£ tumour of the left side of the brain in which the paralysis was on the left side of the body. The post-mortem examination showed th;it tliere was "absence of tlie pyramidid decussation." It ia not stated whether Marchi's method was used in the examination. VOL. I. 14 210 SPINAL COED. entire lengtli of tlie cord, but further forwards it is separated from the neck of the cornu and intermediate grey substance by a layer of nerve- fibres, termed by Flechsig the lateral limiting layer (l. l. l.. Fig. 65). Among the fibres of the pyramidal tract, in the dorsal and cervical regions, degeneration reveals a few other fibres that belong chiefly to the cerebellar tract. The lateral pyramidal tract diminishes in size from above downwards as its fibres end by entering the grey matter ; those that extend lowest (for the leg) occupy the posterior part of the tract in the cervical region. The fibres curve inwards along the septa that extend from the grey matter into the lateral column, and they enter the grey matter between the anterior and posterior cornua. They pass inwards and forwards in the anterior cornu, and are then lost in the ' complicated structure of the grey matter. Their probable termination will be considered presently. The anterior or direct pyramidal tract (called also the " column of Tiirck ") descends the cord in the inner part of the anterior column, adjacent to the anterior median fissure. Its exact form and size vary : usually it bounds the fissure on each side ; some- times it forms only a small tract at the posterior part of the fissure ; when large, it not only reaches forward to the front of the cord, but may cause a pr-^minence on the surface bounded by a distinct sulcus. Its extent down the cord probably varies according to its size. It steadily lessens in area, and, if originally small, may not extend beyond the middle of the cervical en- largement ; if originally large, it may be traced as far as the lumbar enlarge- ment and even into the cord at the cervical, and shows the ascending level of the fourth pair of sacral nerve- degeneration of the post..median ^^ .j,- ^^y -^ bearing the column spreading out against the •'"" " v-^ » _ y ' & commissure. The other figure is USual proportion to the lateral tract, from the lower dorsal, and shows j^ ceases about the mid-dorsal region, degeneration ot the pyramidal ^^ , „ ,, „, ,, i j^-. tracts, anterior and lateral. Most of the fibres pass through the anterior commissure to the opposite side, either entering at once the grey matter, or passing first to the lateral tract.f The latter is probably the course of most of the fibres when the pyramidal decussation is small. Whether any fibres end in the grey matter on the same side of the cord we do not know. Disease of the brain destroying the motor cortex, or the fibres which * Dejerine and Thomas, ' Compt. Rend.,' 1896, p. 157. Russell traces it to the 5th segment. t Although this is probable there is no definite evidence of it except in the sacral yegiou (Russell, ' Brain,' 1898). Fio: 72 — Ascending and descend- ing degenerations from myelitis of the mid-dorsal region ; the upper section is from the lower STETJCTUEE. 21] descend from it to tlie pyramids, causes desc^nrling degeneration. ■ usually limited (at least in conspicu- ous degree) to tlie related pyra- midal tracts, — anterior on tlie same side, lateral on the opposite side (Fig. 73) . But in many cases sligM degeneration lias been also found in the lateral tract on the same side, extending into the lumbar region. Hence it is probable that some fibres of each anterior pyramid find their way to the lateral tract on the same side, and descend to the corresponding limbs, especially to the leg. This degeneration of the lateral tract on the same side as the lesion is sometimes very marked just below the decussation of the pyramids, and is therefore not due to any lower re-decussation in the cord.* Muratoff has shown, by extirpation of the cortical areas for the extremities, that a bundle from the bulbar pyramid descends into the lateral pyramidal tract of the same side. This has been con- firmed by Eiothmann and also by Melius and by Sherrington, who for- merly held a different view.f That there is such a physiological relation is clearly indicated by clinical facts. We shall afterwards see that there is abundant evidence that each hemisphere of the brain is con- nected with both legs, although chiefly with that of the opposite side. There is also a similar and even more equal connection with the trunk muscles, and a slighter con- nection with certain muscles of the arm. Such muscles invariably re- gain some power on the paralysed side, even with a complete inter- PlO. 73. — Descending degeneration of the pyramidal tracts in a case of hemiplegia from disease of the right cerebral hemispiiere. (Prom sec- tions prepared by Dr. Mott.) * Pitres, 'Arch, de Physiologic,' 1874; Hadden and Sherrington, 'Brain,* Jan., 1886. An illustration of this bilateral degeneration will be found in the section on Diseases of the Brain, Vol. II. t Muratoff, ' Neur. Centralbl..' 1893 ; Melius, ' Proc. Royal Society,* 1894 j Sher. 212 SPINAL COKD. ruption to the motor path, and they are weakened on the unparalysed side. The subject is considered further in Vol. II. On the whole, the facts hitherto ascertained suggest that the arrangements which subserve this relation vary in different persons, just as does the chief decussation of the pyramids. The fibres probably in some cases continue downwards on the same side until they reach the level of grey matter for which they are destined.* In other cases most or many of them cross at the bulbar decussation Lastly, there is the possibility that a connection between the motor cells or structures of the two sides may supplement the decussation.f How do the fibres of the pyramidal tract end ^ They seem all to pass into the intermediate grey matter, and forwards into the anterior cornu, among the motor nerve- cells. There they are lost in the plexus of the spongy substance. There is strong indirect evidence that they divide and subdivide, and that their ramifications come into relation with the plexus of nerve-fibrillse constituted by the dividing processes of the ganglion-cells. The evidence of this is twofold. As far as is at present kuown, only one process of a ganglion-cell becomes an axon; the others divide. The axon passes into an anterior root; it can be seen to do so in the case of some ganglion-cells (Fig. 68), and, as we have seen, the number of ganglion- cells and anterior root-fibres is nearly the same in the frog, and therefore, presumably, in man also. Since some root-fibres are not motor, the number of motor cells may safely be assumed to be at least not smaller than that of the motor fibres ; thus each fibre will have at least one cell related to it. If so, since the pyramidal fibres are certainly connected with the ganglion-cells, the connection can only be by the dendrons or ramifying processes of the cells, and this involves a division of the nerve-fibre. The dividing fibre isolated by Gerlach, and shown in Fig. 69, may have been a branch of a pyramidal fibre. The second point in evidence of division is the fact that the nerve-cells and root-fibres must be many times more numerous than the fibres of the pyramidal tract. J But all (or at least most) of the motor root-fibres may be stimulated through the pyramidal fibres, and therefore each of the latter must be con- nected with several ganglion-cells. Physiological considerations sug- gest the same conclusion, which is fully confirmed by the new histo- rington, 'Lancet,' 1894, vol. i ; Rothmann, 'Neur. Centralbl.,' 1896; Redlioh, ibid., 1897. Their results, obtained by the method of degeneration, have been further boine out by the ingenious experiments of Wertheimer and Liepage ('Arch.de Physiol.,' 1897). • Dejerine and Thomas have traced homolateral fibres as low as the 4tii sacral root ('Compt. Rend.,' loc. cit.), Russell to 5th root (' Brain,' loc. cit.). f Broadbent, Hadden. In a unilateial lesion of the cord the paralysed foot may move with the other. Such a connection of nuclei was originally suggested by Broadbent to explain the association of bilateral movements. J The total area of the anterior roots of the cord is probably at least five timea as great as that of the pyramidal tracts in the upper cervical region. STRUCTURE. 213 logical methods to which reference has ah-eady been made.* It is a curious fact that the degeneration method of Marchi does not reveal this wholesale passage of the pyramidal fibres into the anterior coruua. This is probably due to their passing in in the form of non-medullated collaterals. Let us now consider, for a moment, the whole motor path, from the cortex of the brain to the muscles. We may regard it as composed of two neurons, an upper and lower (Fig. 74). Each consists of a ganglion-cell above, an axon, and the terminal ramification of the latter. The upper, " cerebro- spinal " neuron consists of the cortical ganglion-cell with its dendrons, and the " pyra- midal" axon which proceeds from the cell, passes through the brain and cord, and ends in the grey substance by division and terminal inter- lacement with several nerve-cells. The lower, " spino-muscular " neuron consists of the spinal motor cell with its dendrons and the axon jjro- ceeding from it, which passes through the an- terior root and nerve-trunk to the muscle, where it divides and ramifies on the muscular fibre. The elements of the two neurons do not corre- spond in number, since, as we have just seen, each cerebro- spinal element is connected with '/f/'/rv}'/\i \]\' many spino-muscular elements. So, too, each '^^^^'^L^ ^I-^tJ^^y motor axon is connected with a considerable area * Gad and Flatau ('Neurol. Centralbl.,' 1897, p. 481) h;>Te endeavoured to mark out the localisation within the motor tracts of the fibres for different parts of the body. Their method consisted in cutting across the cords of dogs and immediately wpplying to different parts of the cross- section of the lower segment stimuli of varying strength and duration. They found that in general the fibres nearest to the anterior grey matter supplied the body at or near the level of the section, while those fur other regions ran more posteriorly and superficiiilly. This is, however, only what would follow from the fact that the axons of the upper neuron (». infra) terminate by interlacing with the dendrons of the gangiion-cells in the anterior cornna, from which the lower axons to the region supplied by the segment Hrise. Fig. 74. — Diagram of an element of the motor path. Show- ing cortical cell, pyramidal fibre, anterior horn cell, nerve- fibre, and muscle. More than one anterior horn cell should, strictly sneaking, be shown coming into relation with the terminal ramifications of one pyramidal fibre. To show this, however, would have needlessly complicated the diagram. 214 SPINAL COED. C3 Piff. 75. — Dei,'eiieration of the anterO'Iateral ascending tract in a case of locomotor ataxy (q. v, figure), showing its position in the upper cervical region, where the direct cerebellar tract passes outside it into the restif orm body. FiQ. 76. — Ascending defene- ration in thepostero-inedian column and antero-Literal ascendino; tract. The cord was crushed at the first lum- bar segment. Db m^ Dc La L\. Fig. 77.-D'jgeneratiou aftei injury to tlie cauda equina. C a, b, c, upper middle and lower cervical; Da, upper; b, c, lower dorsal ; L a, upper; and L b, middle lum- bar re ordination of movement on the next page. VOL. I. 16 242 SPINAL COED. ment, and tlie lessened tension on the latter makes them contract, each set thus preserving its proper tone. The tone of a muscle seems to be produced by a reflex process, due to a certain state of the motor cells reg-ulated by the impressions from the afferent muscle-nerves. These, as we have seen, are produced by two mechanical influences, the lateral pressure of the fibres (as in the pain of cramp) and the tension on the muscle. An increase of the latter, in passive move- ment, seems to lessen the activity of the cells and permit the fibres to elongate ; a diminution increases the activity of the cells and causes the fibres to shorten. It further appears that the tone of a muscle is influenced through the spinal cord by the condition of its antagonists. Thus the knee-jerk may be increased by cutting the sciatic nerre — i. e. the nerve to the flexors, or diminished by stimulating it. An increase similarly results when the hamstring muscles (the antagonists of the quadriceps) are relaxed by flexion of the knee.* Co-OEDiNATioN OF MOVEMENT. — The co-ordination of muscular contractions, which results in the ordination or ordering or arrange- ment of movement, has been already described (p. 7), so far as its general features are concerned. We cannot ascribe to the spinal cord any process that can be designated the arrangement of movement ; since the muscular contractions correspond to the activity of the motor cells of the cerebral cortex, and to the corresponding impulses along the pyramidal fibres. These determine the initial activity of the motoi- cells of the cord, both for the muscles that move a part and for those that oppose the action of the others and give steadiness and uni- formity to the movement. But these impulses from the brain descend on spinal cells that are not in a passive, inactive, functionless state. Such a state probably never exists, for even when there is no voluntary activity there must be the activity on Avhich the tone depends, — that, as we have just seen, must exist in all postures of the limbs. This state of the cells preceding voluntary activity is determined by the afferent impulses, chiefly by those from the muscles. Through these the muscles are adapted to postiire, and in the mechanism for adapta- tion to postuxe we may trace also a mechanism for part at least of the co-ordination effected in the spinal cord. This seems to consist of two parts. (1) An automatic variation in the state of muscles, per- mitting the ordered performance of intended movements. The state of the afferent impulses acting from the muscle on the motor cells must be at once altered by the effect of the voluntary activity of the muscles, since this will alter the impulses in the muscle-nerves by the changed and changing pressure and tension on the tissues in which these nerves end — the pressure of the contracting and widening fibres and the tension in the antagonists that oppose the motion, but do not prevent it, and are made more tense by the muscles they are opposing. These impulses pass to the cord, and there act on the motor cells, and influence their state in a way that we can at present only guess at, but • See Shemng-'on, 'Brit. Med. Journ.,' 1893, vol. ii, p. 685. FUNCTIONS. 243 which, must be of the utmost importance. There must of necessity be a definite relation between certain states of the muscle and the strength of afferent impulse produced thereby. If we conceive that an increase in the impulse (making it greater than corresponds to the degree of activity of the motor cells), such as must resiilt from the increased tension on the muscle, lowers the activity of those cells, we can understand the way in which the contracting antagonists relax to permit movement which tends to occur. As soon as the resistance begins to yield, the tension-stimulus will be increased, and the total afferent, impulse become disproportionately great in relation to the degree of activity of the cells ; as a result, this activity is lessened and the muscles yield. This involves a constant regulation of the activity of the various motor cells by the afferent impulses. A like but opposite effect must be produced on the cells of the muscles producing the movement. This effect on the cells will, of course, blend with that of the voluntary impulse from the brain that is causing the movement. Thus the spinal muscle-reflex process permits the desired movement to take place, as it could not do if the state of the cells were not thus automatically regulated. (2) Relations between the various reflex processes are doubtless established by the repetition of movements, and thus planned mechanisms, as it were, are established in the cord ; within their range the various movements occur. The state of the muscles in standing, for instance, is almost perfectly reproduced by the extensor spasm that occurs when the muscle- reflex processes are in great excess. Thus we have a mechanism by which a relatively simple voluntary impulse may produce an extensive co-ordinated movement. But what we can discern shows that we must regard spinal co-ordina- tion as essentially a reflex process, chiefly due to the impulses from the muscles. The correctness of this view can hardly be doubted when we come to see its perfect harmony with the phenomena and the con- ditions of spinal inco-ordiaation. Stm it must be always remembered that this spinal process is of the nature of a subordinate mechanism, determining the precision of form rather than the actual arrangement and order of the musctdar contraction. This is done by a higher process, a co-ordination which consists in the form of action of the motor cells of the cerebral cortex that is produced by stUl higher volitional processes. These, however, as we shall see, are themselves subject to a like influence and the seat of an analogous regulation, chiefly, it is probable, by impulses proceeding from the cerebellum, which are also due to the varying excitation of the muscle-nerves. That the nerve-fibres which pass up the posterior median columns conduct impulses from the muscles that determine cerebral co-ordination scarcely admits of doubt. Interrup- tion of this path in any part of its course causes a defect of co- ordination, which resembles that due to cerebellar disease with sufficient closeness to add weight to other facts suggesting that it is through the cerebellum that the impulses carried by this path act on the 244. SPINAL CORD. cortex, regulating and determining the activity of its cells and tlie resulting movement.* The impulses may reach the cerebellum, as we have seen, from the grey matter of the post-pyramidal nucleus in which these fibres end.f But this primary co-ordination is not a function of the cord, although it may be lost in consequence of disease of the cord. The direct cerebellar tract may constitute a similar path, but of this we have only the evidence of destination and analogy. It is probable that the mechanisms just alluded to, as constituted by the functional relations between the motor and sensory structures in the cord, very much facilitate the execution of many movements, and especially of those that are the more simple in their character. The less variation a movement is capable of, or needs, the more largely may the spinal mechanism be concerned in its arrangement ; and hence such actions as standing and walking may be effected through a comparatively small number of the pyramidal fibres, and, as we shall see, they may still be performed when there is disease that would prevent a more elaborate action. It is also probable that in animals such spinal mechanisms are developed to a greater extent than in man, and care must be taken in drawing inferences from one to the other. The impulses from the muscles that determine the muscle-reflex action and the spinal co-ordination, must pass by nerves that end in the grey matter and come into relation with nerve- cells, at or near the level at which they enter the cord. We do not know whether it is through these fibres, or through those that pass upwards without interruption, that the impulses are conveyed which, when excessive in degree, give rise to muscular sensations. But attention may again be called to the important evidence, afforded by such sensations, of the abundance of upward impulses of which we are normally unconscious. These nerves, it will be remembered, begin in the connective tissue of the muscles, and probably also in the muscle-spindles, and the acute pain of cramp, and the muscular tenderness in such affections as multiple neuritis, afford indirect evidence of impulses which we do not usually observe, and might almost doubt ; while the manner in which such pain is excited is very clear evidence of the sensitiveness of the nerves to the modes of stimulation that have been assumed as effective. We have already seen (p. 17) that it is through such unfelt impulses that we probably derive the chief 'part of our conceptions of posture, a subject that must again be considered in connection with the brain. Inflitence on Nijteition. — The nutrition of the muscles is under * This has been experimentally confirmed by Bechterew, who finds that section of the posterior columns, in various animals, above the lumbar enlargement causes a defect of co-ordination similar to that produced by loss of the cerebellum (Beclite- rew, • Wjestnik psich. i. nevropafc.,' 1889, vii, 1 ; and ' Neur. Ceiitralbl.,* 1890, p. 82.) t A connection since confirmed by Brosset, * Des Connexions du Cervelet,* Paris.. 1891. FUNCTIONS. 245 the coutrol of the anterior grey matter, and probably of the motor nerve- cells. The influence is exerted through the motor nerves, and indeed consists in the normal integrity of the- fibres (see p. 29). The nutrition of the bones smd joints is also under the control of the cord, and probably is exerted through the posterior roots. It is true the grovrth of the bones is hindered when the anterior cornua are diseased, but no atrophic change seems then to occur in the osseous structure, and the influence of the paralysis may be indirect. A true trophic change, and an alteration in the joints, may occur in locomotor ataxy, in which the disease is of the posterior nerve-fibres. The nutrition of the skin seems also to depend on nerves that have their coxirse in the posterior roots. The clearest fact is that irritation ■of the nerve- structures has far more effect than simple loss of function. It is when the cord or nerve-roots are the seat of irritative inflam- mation that the most acute trophic changes occur, while mere degene- ration of these nerves induces slower and slighter changes (see p. 28) . In a dog in which the spinal cord below the cervical region was removed piecemeal, trophic changes in the skin followed the section, but not the subsequent removal. It is hence doubtful whether trophic fibres actually take origin (i, e. have " centres ") in the cord ; in all cases it is difficult to exclude the effects of the fall of blood- pressure.* "Visceral Contkol. — Although the viscera are under the immediate I Pectoralis (clavicular part) \ j Serratus >■ I Plexors of elbow 1 Pronators, triceps J Ext Deltoid and other shoulder • muscles, and ■ sternal part of pectoralis > Flexors of wrist and fingers " 1 Muscles of hand • J) 1 J Extensors of thumb • Lower part trapezius and back mascles 2 3 4 5 6 7 8 9 10 11 L.l r Lumbar muscles Peroneus, C flexor of ankle, J extensor of ] ankle 1 } Intercostals • Abdominal miiscles Ileo-psoas • Cremaster , a J Flexors of hip , , 1 Extensors of knee • ^ J Adductors of hip . y Extensors and abductors of hip .} Plexors of knee V Intrinsic muscles of foot . 2 8 4 y Periuseal and anal mascles. Abdominal. Cremasteric. Gluteal. \Foot- J clonus. Plantar. SYMPTOMS. 253 SYMPTOMS OF BTSBASH OF TEF SPINAL COB,D : INDICATIONS OF TEE SEAT OF TEE LESION: ANATOMICAL DIAGNOSIS. The symptoms of disease of the spinal cord consist in derangement of its various functions ; the loss of some, the exaltation and perver- sion of others. We have already considered these functions, and the parts of the cord by which they are subserved. We may now briefly consider the general character of their derangement, and its signifi- cance in regard to the position of the disease. The combination of symptoms indicates the seat of the lesion ; we infer its nature from their mode of development, and other considerations, which will be subsequently discussed. It is always important to keep these two elements of the diagnosis distinct in the mind. A common feature of the symptoms of disease of the spinal cord is their bilateral character. This depends on two causes, of which, however, only the first is peculiar to the cord, and can be regarded as the special cause of this feature of its diseases. The structures in each haK of the spinal cord are in such close proximity, that any random process, such as haemorrhage or inflammation or pressure, readily affects both halves — can, indeed, hardly fail to do so in some degree, and usually to such an extent as to cause the bilateral cha- racter of the symptoms to be obtrusive. Secondly, morbid processes that commence in the nerve-elements and affect them according to their function (" system diseases ") usually involve the corresponding structures of the two sides, and the spinal cord contains many struc- tures that are liable to such processes. Hence a large proportion of the diseases of the spinal cord involve both sides and cause symptoms that have a corresponding range. The leading fact that results from this is, that the characteristic type of palsy is " paraplegia." The word means literally paralysis of the parts beneath or beyond a certain locality, and involves the distinction of a motionless part of the frame, which no doubt arose from the variable extent of this, in comparison with the uniformity of the region affected in "hemiplegia." But the second condition causing the bilateral character of the symptoms is shared equally with those outlying parts of the spinal cord — the peripheral nerves ; and as this condition obviously determines a stricter symmetry than does the first, it follows that this character is not, alone, of much significance, and is indeed least significant when most complete. In the affections that are strictly symmetrical, therefore, other features must also be taken into account. Another character of spinal symptoms, not shared by those of the nerves, consists in their variation in vertical extent according to the position or extent of the lesion. But we must distinguish two classes of symptoms within the region in which they exist. (1) Those which depend on the interruption of the conducting path to or from the brain. 254 SPINAL OORD. and involve the whole region below the disease. (2) Those which depend on damage to the central structures in the cord and nerve- roots, which are present only at the level of that damage, i. e. in the parts functionally related to that part of the cord. The two sets of symptoms may be distinguished as " conducting " and " central ; " but in many diseases those at the level of the lesion are chiefly due to the irritation of the nerve-roots, and these are most usefully designated "root symptoms." Disease of the cord does not always cause bilateral symptoms. A. little consideration will show that this must be so. A random process, of small extent, may damage one side only. It may affect one or several structures on one side or all of them. Nevertheless it is very rare for such a process to spare the other side altogether, and practically no lesion affects all parts of one side without damaging, in some degree, the other side, at any rate for a time. In very rare forms of traumatic lesion, however, the damage to the other side is almost imperceptible. Again, " system diseases," in quite exceptional cases and for unknown reasons, are limited to one side ; much more frequently they may affect one side earlier and more than the other. Such unilateral symptoms indicate a condition awkwardly termed " hemi-paraplegia." MoTOE Symptoms. — Loss of motor power results from interference with the motor path in any part of its intra-spinal course, — ^pyramidal tracts, anterior grey matter, anterior nerve-roots. We have seen that the path may be divided into two segments, upper and lower (see p. 213). The spinal cord contains a considerable portion of the nerve- fibres of the upper segment, and their lower termination in the grey matter, but only the commencement of the lower segment, the motor ganglion- cells, and root-fibres proceeding from them. The chief part of the lower segment is outside the spine, in the nerve-trunks. So far as the loss of power is concerned the effect is the same, in whatever part of the motor path the interruption is situated; but the other symptoms that accompany the loss of power differ very much accord- ing as the interruption is in the upper or lower segment. The lower segment influences muscular nutrition, and forms part of the path of reflex action. Hence, as we shall presently see, the muscles waste, and reflex action is lost, when this is diseased; but when the upper segment is damaged there is no musctdar wasting, and reflex action, instead of being lost, is commonly increased. The symptoms pvodiiced hyi disease of either segment are essentially the same, whatever part of the segment is diseased, whether the cell at the upper extremity, the fibre, or the ramification at the lower extremity of the fibre. If, for instance, the intra-muscular nerve-endings are paralysed by curara the symptoms produced are the same as if the motor fibres in the nerve- trunks are divided or their cells in the cord are destroyed. Disease of the termination of the upper segment in the grey matter of the cord must, of necessity, produce the same effect as disease of the pyramidal SYMPTOMS. 255 fibre itself, or the cell in the cerebral cortex from which the fibre Bprings. We shall afterwards see that this consideration has very im- portant applications. If a fibre of either segment is seriously damaged, it degenerates below the division, since its nutrition depends on the influence of the cell from which it has sprung. If damaged only by pressure, however complete may be the evidence of degeneration, regeneration is possible, even after one or two years. It is possible that such regeneration also occurs when the damage is by inflammation. The nutritional stability of the fibre, or rather of its essential element, the axis-cylinder, becomes less, and more easily deranged, the greater the distance from the parent cell, and it is least in the terminal ramification of each segment. This is probably the reason why curara acts chiefly on the intra-muscular nerves, and it explains the influence of many poisons on the peripheral nerve-endings, and the facts of nerve-degeneration in tabes and multiple neuritis, &c. The law is probably also true of the upper segment; and if so, many facts of pathology become clearer to us, as will be seen in the chapter on spastic paraplegia. It may thus be taken as a general law of the utmost importance that the vitality of the processes of a neuron and their power of resisting morbid influences diminish in proportion to their distance from the cell hody of which they are really part. A lesion of the pyramidal tract causes loss of power in all parts below the level of the disease — that is to say, of all parts the fibres for which are interrupted. A lesion of the grey matter, or of the anterior roots, causes paralysis only of those parts which are functionally on the level of the lesion. The two mechanisms often coincide. A transverse lesion in the cervical enlargement, for instance, may cause paralysis of the arms from the damage to the grey matter and nerve- roots, and paralysis of the legs from damage to the pyramidal fibres. The disease involves, primarily in the former case, the commencement of the second segment of the motor path for the arms ; in the latter, the middle of the upper segment. The associations of the paralysis differ accordingly. The parts affected by a lesion at any level will be readily ascertaiaed by an examination of the table of functions on p. 252. It is important to note that the affection of motor power is often incomplete. It may then involve one set of muscles more than another. The flexors or the extensors may be chiefly paralysed. In disease of the dorsal cord, it is very common for the flexor muscles of the hip and knee to suffer more than the extensors. Why this should be we do not know, but the fact is important, because con- siderable weakness of the flexors of the knee is readily overlooked. In examining motor power each set of muscles should be separately tested. Motor over-action ; Spasm is frequent in disease of the spinal cord and its membranes. It may present the form of tonic spasm, which 256 SPINAL CORD. when persistent is termed rigidity ; or of clonic spasm, which is nsually transient and paroxysmal. Tonic spasm, persistent, and involving only a certain group of muscles, causes distortion of the parts to which they are attached, and is often termed contracture.'* Tonic spasm, paroxysmal or persistent, is far more frequent than clonic spasm, which occurs chiefly in association with tonic spasm as the muscular clonus described at p. 22, or as a consequence of certain functional derangements. Tonic spasm may be the result of direct u-ritation of the motor structures, or may depend on over-action of the reflex centres, due not to irritation, but to deficient control. Either form may be acute or chronic. The acute irritation which causes spasm is generally inflammation of the membranes, rarely an acute lesion of the substance of the cord. The chronic irritation is chiefly due to compression of the motor fibres — either of the pyramidal tracts, when there may be persistent unvarying spasms in the parts below the disease, related to the fibres irritated, — or of the nerve- roots, when similar spasm is produced in the parts at the level of the lesion. The spasm that depends on reflex action is seen chiefly in the legs and trunk, but especially in the former. It may preponderate in either the flexors or extensors, so that the legs, when rigid, may be drawn up or straight out. The flexor spasm seems to be due to an over-action, of the centres for cutaneous reflex action, the extensor spasm chiefly to that of the centres for muscle-reflex action, although it may also be excited indirectly by a cutaneous impression. This form will be considered in connection with the reflex over- action. Muscular Contraction. — The actual shortening of muscles, by which they cannot be passively extended to their normal length, is due to tissue changes fijxing the active persistent tonic spasm or contracture just mentioned. The rapidity with which it occurs depends on the uniformity of the spasm, and we may distinguish three modes m which it arises, which differ in the time required and degree attained. (1) When one set of muscles is paralysed, their opponents, aever being extended, quickly become fixed in the contracted condition which they assume in virtue of their power of adaptation to posture. Thus in palsy of the flexors of the ankle, the calf muscles quickly become contracted, so that the foot cannot be flexed on the leg even up to a right angle. The same thing happens by a similar mechanism, when one posture is unceasingly maintaiaed and one set of muscles is never extended, e. g. persistent flexion of the knee leads quickly to structural shortening of the hamstring muscles. (2) Where there is unchanging active contracture from chronic irritation of the motor fibres by a growth, or permanent reflex contracture, as when reflex flexor spasm keeps the hip and knee permanently flexed, similar structural changes occur, so that passive elongation soon becomes * The reverse of this condition, loss of museular tone permitting unusnal freedom of passive movement, is described in tabes under the name of hypotonie musculaire (Frenkel). SYMPTOMS. 257 impossible. (3) In paroxysmal tonic spasm of intense degree, if one Bet of muscles is stronger tlian their opponents, their action may so preponderate as to lead to a greater active contracture than their opponents present, and permanent shortening may occur; although it does so slowly and to a slighter degree than in the other forms because the muscular action is more or less paroxysmal and varying, and the muscles are at times extended by their opponents. Thus in paroxysmal extensor spasm in the legs, no shortening occurs in the muscles moving the knee, because they are equally balanced, but the calf muscles, being stronger than the flexors of the ankle, contract the more, and extend this joint, whenever a paroxysm of spasm conies on, and, after a time, may undergo slight structural shortening, so that the foot cannot be flexed on the leg beyond a right angle. It is of great importance to distinguish the shortening of muscles due to tissue changes in them, from the active contracture that may closely simulate.it. In the latter, gentle extension, kept up for a few minutes, restores the muscle to its normal length. The importance of the distiaction is due to the fact that the structural shortening can be removed by tenotomy or forced extension, while these measures are useless in the case of active contracture, which would subsequently reassert itself. Tremor is a symptom which should be mentioned, for it is at least associated with disease of the spinal cord in insular sclerosis (see Vol. H). It also occtirs in degenerative diseases, such as paralysis agitans or general paralysis, and as the senile tremor of old age. In these conditions it probably depends upon changes in the cerebral cortex. It is characteristically present in toxic conditions manif estiag themselves chiefly in affections of the peripheral nerves, such as those arising from alcohol, lead, and mercury. The spontaneous twitchings of muscular fibres known as " fibrillary twitchings " occur especially in association with degenerative disease of the anterior cornual cells. Inco-ordination of movement, although motor, depends usually on disease of afferent fibres. Its characters have been already described in outline (p. 10). It occurs in three forms, of which the third differs entirely from the others in aspect and nature, and alone is a true motor symptom. The two chief forms are the following: — (1) Simple disorder of voluntary musctdar contractions, which, when considerable, amounts to a wild irregularity of movement, and when slight is only manifested by slight irregularity when the guidance of vision is withdrawn — as in the inability to maintain the muscular contractions in the perfect uniformity needed for equilibrium when the base of support is ren- dered small by the juxtaposition of the feet. The delicacy of the test is increased by the removal of the firm base afforded by the boot, and by closure of the eyes. The increase in unsteadiness when the eyes are closed is sometimes termed "Romberg's symptom." This con- dition results from interruption of the afferent path from the muscles VOL. I, 17 258 SPINAL CORD. to the spinal cord, including the fibres that ascend the cord ana those that subserve the muscle-reflex process at the level of entrance. The effect of the loss of the latter is a cessation of the chief part of spinal co-ordination, which, as we have seen, depends on those processes, co-operating with the voluntary impulse. Hence it is associated with loss of the knee-jerk. The loss of other forms of reflex action does not seem capable of causing inco-ordination. In complete interrup- tion of the root-fibres from the muscles the mechanism of the next form is necessarily conjoined. (2) Inco-ordination resembling the slighter degrees of that just described, and consisting especially in such a defect of equilibrium as results from disease of the middle lobe of the cerebellum, is produced by disease of the posterior median columns above the lumbar enlargement, or, if it extends into the latter, leaving the root-zones free so as not to impair muscle-reflex action. This is apparently produced by interru|.)tion of the path by which impressions from the muscles are conveyed to the posterior nuclei of the medulla, and probably thence to the cerebellum (p. 244). The effect is to deprive the motor cortex of the guidance afforded by these impulses. The difference between this form and the slighter degrees of the first is that the muscle-reflex action is not lost, the knee-jerk being preserved. They are both spoken of as ataxy also. (3) Irregular compression of the motor fibres in the cord apparently causes the peculiar jerky inco-ordination seen in disseminated sclerosis, which is supposed to depend on unequal and irregular conduction along the fibres, due to their compression. This form, however, needs further study. Sensoky Symptoms. — Loss of sensation is a very common effect of disease of the spinal cord. It may be total, and involve all forms of sensibihty, or partial, and affect only some forms. The statements made on pp. 13 — 19 regarding impairment of sensation generally, and the method of ascertaining it, apply to that which results from cord disease, and need not be here repeated. It has been also pointed out (p. 78) that loss of sensation occurs less readily than loss of motor power. In cord disease it is common for muscular paralysis to exist with intact sensibility. This may partly depend on the fact, ascer- tained by experiments on the effect of local anaemia of the cord, that the sensory fibres, of the nerve-roots at least, seem to have more resisting power than the motor fibres. Sensation may be impaired by disease of any part of the sensory path-^posterior roots, probably also the posterior cornua and commissure, or the conducting tracts up the cord. A division of the sensory path into upper and lower seg- ments is conceivable, analogous to that of the motor path, although we have not the same clear ground for the distinction into simple segments of similar composition. Histological researches show that most of the centripetal neurons have short axis-cylinders, and suggest that upward conduction is subserved by a number of relays. Disease of the posterior nerve-roots causes loss of reflex action as well as impairment of sensation, just as disease of the anterior roots SYiMPTOMS. 259 interferes with reflex action as well as with motor power. Internip* tion of the sensory conducting* tracts higher up leaves reflex action unaffected. But a focal lesion, such as transverse myelitis, may damage both the conducting tracts and the nerve-roots at the level of the lesion, or may affect only one of these. Disease outside the cord, compressing it, may have the same double effect. Hence it is impor- tant to test sensation at the level of the lesion, as well as in the parts below, and to remember that the " level of the lesion " may involve the limbs or the trunk. Areas of anaesthesia may thus be found on the trunk when there is none on the legs, and may be of considerable diagnostic importance, e.g. in spinal caries. Eandom disease of the nerve-roots outside the cord usually impairs all forms of sensibility, although slight damage may arrest the conduction of tactile impressions, and not those of pain, which are probably more energetic. Disease of the roots within the cord often causes only partial loss, because the fibres which conduct different impressions have a different course. But loss of one form of sensi- bility from disease of the root-fibres or nerve-fibres usually depends on the kind of disease, and is especially due to degenerative changes, the result of some present or past local influence. Disease higher up the cord still more frequently causes partial loss ; either sensibility to pain or to touch may be impaired. That to temperature is rarely affected without that to pain. We do not yet know precisely the significance of this special form of loss, because, as we have seen, we are still uncertain as to the path for each form of sensibility. It is highly probable, however, that loss of sensibility to pain is produced by disease of the grey matter immediately anterior to the postero- median column. Disease of the posterior median column, and possibly that of the direct cerebellar tract, certainly impairs the conduction of impressions from the muscles. It probably abohshes the " muscular sense " of posture and movement, although this does not entail a distinct sen- sory loss. But there may be also a greater loss of muscular sensibiliiy, so that the normal sensitiveness to pressure and passive extension (and even at last to electrical stimulation) may be impaired or lost. The " common sensibility " of muscles is probably lost only when the disease of the nerves is greater than suffices to abohsh what is termed the " muscular sense." Interference with this path in the nerves or roots outside the cord abolishes muscle-reflex action, and also causes more pronounced symptoms (ataxy, &c.) than disease higher up the path within the cord. Increased sensitiveness, hypersesthesia and hyperalgesia, are also common in disease of the spinal cord, and usually depend on irritation of the conducting fibres in some part of their course. Probably the irritation produces the effect by intensifying the imjDulse as it passes, since the phenomena of stimulation of nerves show that their axis- cylinders have some power of transforming other forms of energy into 260 SPINAL COBD. nerve-force, i.e. of evolving nerve-force, and therefore of increasing the strength of that which passes along them. The term " hyperaesthesia " is commonly used in the sense of "hyperalgesia." In the strict sense of the word, hyperaesthesia is seldom observed or even searched for. When the sensibility to touch is " increased " there is some perversion of the sensation, not a simple increase. The sensation may be felt as "thrilling" or "shock-like sensations." When there is an extreme increase, pain may be pro- duced by a touch, but it is more probable that the touch stimulates the over- sensitive nerves of common sensibility, than that actual pain is produced through the tactile nerves. A touch may cause pain when it js not felt as a touch, as in the condition termed "anaesthesia dolo- rosa." Delayed sensibihty to pain, or temperature especially, is common in tabes, and is occasionally met with as a restdt of other changes in the spinal cord. Impairment of sensibility for pain and temperature with retention of ordinary tactile sensibility is charac- teristically met with in syringomyelia. Other forms of altered sensi- bility have been already described. Ptim, referred to the spine, occasionally present in organic disease of the cord, is more frequent in disease originating in the meninges or bones. But the frequency with which spinal pain is present in abdominal, especially gastric disease, and in neuralgic affections, lessens its significance when it exists alone. In meningitis, acute or chronic, and in meningeal growths, spinal pain is frequent, and in organic disease of the bones of the vertebral column it is an almost constant symptom, and is combined with local tenderness. The same combination of local pain and tenderness frequently occurs in cases of neiu'algic pain, " rachialgia," — a condition that is often loosely termed "spinal irritation," especially when it succeeds, as it often does, concussion of the spine. Such pain is usually felt through a consider- able extent of the vertebral column, or has more than one place of chief intensity and tenderness. That which is due to organic disease is usually fixed and unchanging. In organic disease of the cord itself pain is more often referred to the neighbourhood of the spine, to the loins or the sacrum, than to the spinal column itself. Still more important are the pains that are referred to the parts to which the sensory nerves are distributed, and have hence been termed " excentric " or "radiating" paias. They are of two kinds: (1) those due to the irritation of the posterior nerve-roots in their passage through the intervertebral foramina, through the membranes, or through the posterior colxmins of the cord ; (2) those produced by irritation of the sensory conducting tracts. The pains of the first class are called " root-pains," and are often intense. They correspond in level to the disease. Those of the second class are sometimes acute, especially in lesions that irritate the conducting tracts by pres- sure, e. g. growths. More often they are dull pains, closely resembling rheumatism, and frequentlv mistaken for rheumatism by the patients SYMPTOMS. 261 tliemselves and tlieir medical attendants. The mistalre is the more easily made, because other symptoms suggestive of spinal disease may be inconspicuous, and the rheumatoid pains in chronic cases may be influenced by weather, being mu^^h more troublesome in damp and cold than in fine and dry weather. In all cases, persistent rheumatic pains in the limbs should suggest the possibility of spinal disease, and watch should be kept for such symptoms as local loss of power, or alterations in reflex action. There is a third class of pains— resem- bling root-pains — which depend on degenerative changes in the nerve- fibres ; the molecular alterations that result give rise to upward impulses of considerable intensity. They are met with in locomotor ataxy and in multiple neuritis, and may be dull as well as acute. The position in which these various radiating pains are felt — legs, trunk, or arms — dep' nds upon the seat of the disease. Although often produced in the root-fibres, these pains may also be due to the peri- pheral nerves. It is especially important to note that the root-pains are frequently felt as a sense of constriction, a painful sense of tightness, as if a band were tied tightly around the part — the "girdle- pain," as it is called. When there is transverse damage to the cord, at the lowest part of the healthy region there is a state of irritation of the sensory nerves, and this irritation (referred to the nerve-endings) causes the girdle-pain. It is named from its frequency at the level at which a girdle is worn, the middle of the trunk, which depends on the dorsal region being the most common seat of disease; but it may be felt lower down, about the groins or even the legs, or higher up, in the arms. In the limbs it is a mere sense of tightness. The girdle-pain is a symptom chiefly of inflammatory and degene- rative processes within the cord. Pressure on the nerve-roots usually causes acute pain, but the most severe root-pains are those met with in disease of the bones of the spine. These have also, more than any other kind, the characteristic that they are increased by movement, and in growths commencing in the bones (which are usually malig- nant) this feature is of considerable diagnostic importance. The suffering in such cases is so great as to have gained for the resulting symptoms the ominous designation of paraplegia dolorosa. The pain in this condition may have a localising value, that in carcinoma being frequently referred to the neighbourhood of the column, while in caries it seems more frequently to affect the side of the chest. Spontaneous sensations, other than pain, are very common in disease of the spinal cord, and are often of considerable diagnostic im- portance, but suggestive rather of the presence of a morbid state than of its nattu-e. They may present many varieties of character, but the familiar sensation produced by pressure on a nerve-trunk, when the part is said to be "asleep," or to have "pins and needles," is the most common and the most significant. It may occiir in functional disturbance of the cord as -well as in organic disease, and also is very 262 SPINAL CORD. common in peripheral nenritis. It depends on over-action of the sensory structures, but it has at present no special significance as to the locality of disease. It may be excited by contact when it is not spontaneous, and probably represents the highest degree of excess of impressions conveyed by the nerves of tactile sensibility. The still vaguer feeling called " numbness" is also common, and may occur, in slight degree, in diseases of which all other symptoms are purely motor. But this word is used in so many different senses that the meaning in which the individual uses it should always be ascertained as far as possible. Sometimes it signifies distinct loss of sensibility j more often a feeling as if there ought to be loss when there is not. Our sensations altogether transcend our vocabulary, but the observer must try (without leading) to ascertain the character of the sensation experienced. Eeflex Action. — Loss of reflex action indicates an interruption of the reflex arc concerned. This interruption may be anywhere between the peripheral endings of the motor and sensory nerves, and thus is not necessarily withm the spinal cord, or even within the spinal canal, [t is as constant in peripheral neuritis as in any spinal disease. The position of the interruption must be determined by the associated, symptoms ; if it is in the centripetal portion of the reflex arc, there ia impairment of sensation, since the interruption will equally arrest conduction to the brain. If it is in the centrifugal portion of the arc, there is a corresponding interruption in the path of the voluntary im- pulse, and loss of motor power. Moreover disease of the motor centre or motor nerves causes also degeneration of the nerves and wasting of the muscles. Any considerable disease of the nerves abolishes all reflex action from the part they supply, but disease limited to the motor structures may permit a reflex movement to take place at a distance, although preventing it at the part stimidated. Disease of the motor centre or nerves causes loss of all fonns of reflex action, the simple form and the muscle-reflex that underliea myotatic irritability. Partial disease of the afferent path may impair one and not the other, may abolish the muscle-reflex action (myotatic irritability) and not the superficial reflex action, since the afferent nerves for the two are distinct, coming in the one case from the muscles, in the other from the skin. When one only is lost it is generally the muscle-reflex action ; the nerves for this seem more sus- ceptible, and to have less power of resisting morbid influences. Loss of all reflex action may occur as a transient symptom, imme- diately after the onset of an acute lesion of the cord, apparently from irritative inhibition of the centres. Cutaneous reflex action may be lessened permanently in some cases of brain disease on the side of the motor palsy, even when the muscle-reflex action is increased. Indeed, this opposite change in the two forms of reflex action co-existing on the same side always suggests intra- cerebral disease. It may be well again to remind the reader how difiicult it often is to be sure whether SYMPTOMS. 263 the 1< nee-jerk is present or is lost, on accconnt of tlie readiness witli which its occurrence may be prevented by inability to relax the muscles, and its presence may be simulated by a true reflex action (see p. 238). Excess of reflex action implies, of necessity, the integrity of the reflex arc concerned, and shows that organic disease, if it exists, is higher up the cord. Each form of reflex action is often increased. In some acute diseases, as acute meningitis, and probably also in some chronic diseases, the increase may be due to an irritation of the centres, but in most forms of chronic disease it is apparently the result of a loss of control, and indicates disease between the centre concerned and the brain. We have already considered (p. 240) the probable mechanism, and have seen that the excess of the muscle- reflex action is related to disease of the pyramidal fibres, and espe- cially to the loss of the terminal part of these fibres, within the grey matter, adjacent to the centres concerned.* This is the significance of considerable excess. Degeneration of the terminal portions of the fibres is commonly due to a descending degeneration of the fibres them- selves. It is possible, however, that the degeneration of the endings of the pyramidal fibres may be primary, as is that of the nerve-fibres. (See Primary Spastic Paraplegia.) The increase of reflex action is chiefly manifested in the legs, in which reflex action is normally more active and important than in the arms. The increase in the cutaneous reflex action is shown by its occurrence on a shghter stimulation of the stin, and by a greater degree and extent of the mxiscular contrac- tions produced. In these the flexors usually predominate, so that the leg is drawn up in a strong movement. As the action of the sexual organs depends, in part, on superficial reflex processes, priapism is common when the reflex excess is great. The increase of the muscle- reflex action is shown by an increase of myotatic irritability, and therefore of the so-called "tendon-reflex contractions," — the increased knee-jerk, rectus-clonus, foot-clonus, wrist-jerk, elbow-jerk, jaw-jerk, jaw-clonus, &c. These have been already described. As already stated, the excess of this irritability is at first moderate, and slowly increases. A high degree of over-action is never suddenly attained, as it may be in the case of cutaneous reflex action. It would seem as though, in the centres liberated from control, a capacity for excessive action is slowly developed, which ultimately results in tonic spasm. Not only is the common cause of this excess damage to the pyra- midal trac+s higher up the cord, entaihng their secondary degenera- tion; but if such disease higher up — as, for instance, primary myelitis * It is interesting to note the .inalogy between the effects of degeneration of the termination of the two segments of the motor path. The increased activity of the muscle-reflex I'entres, which results from degeneration of the termination of the upper segment, presents some similarity to the increased voltaic irritability of the muscular fibres which results from degeneration of the termination of the lower seamen D. 264 SPINAL COED. or in jury to the cord — is followed by abolition of the muscle-reflex action in tbe parts below, it is the result of inflammatory damage to the lower part of the cord in which the centres are situated, generally by a descending myelitis. Sometimes the original myelitis involved the whole or a considerable part of the cord below, and the indications of a transverse lesion were merely those of the upper limit of the disease. It is not uncommon for the secondary myelitis below an original transverse lesion to succeed it, and abolish the reflex action which was at first unimpaired. I have several times met with such a sequence. A primary dorsal myelitis has left reflex action in the legs unimpaired and tending to excess, with the sphincter ani in its condi- tion of uncontrolled automatic action, when after a few days, a week or more, indications of a recurrence of myelitis have been attended by abolition of all reflex action, including the knee-jerk, by flaccidity of the muscles, with rapid development of the reaction of degeneration in them, and by complete relaxation of the sphincter ani. This is the state from the first in the cases in which the primary myelitis involves the whole lower part of the cord. Sometimes, indeed, such descend- ing inflammation is limited to the grey matter or to the posterior columns, with corresponding limitation of the symptoms, but with a similar abolition of reflex action. Of course, such descending inflam- mation is a very differ, it thing from the secondary descending degeneration of the pyramidal tracts* Over-action may perhaps be also produced by a state of irritation propagated from above, as in the " early rigidity " of hemiplegia ; we have seen that the motor impulses probably pass from the pyramidal fibres through part at least of the muscle-reflex mechanism. Primary over-action seems also to occur, although apparently it only attains a slight degree. It is probably the cause of the trifling excess met with in cases of defective nutrition of the spinal cord or of the nervous system generally. Reflex spasm. — We have seen (p. 26) that the muscular state on which myotatic irritability depends, assumed to be due to a muscle- reflex action, is probably identical with physiological tone. When- ever there is a considerable increase in the irritability there is a tendency to tonic spasm, in which there is a balanced contraction of the muscles, fixing the limbs in the position of extension. At first there is merely slight stiffness of the legs, especially felt on waking from sleep ; afterwards the legs, when extended, become distinctly stiff, although they may be quite supple when flexed. If gradually * In consequence of the occurrence of this inflaramation in the lower part of the cord having been overlooked, it has been thought that a transvertie lesion higher up has the power of abolishing reflex action bel i\v, where the cord is not damaged except by descending degeneration. See, however, p. 272, note. In one case, how- ever, described by Bruns (* Arch, f . Psychiatric,' vol. xxv), the knee-jerk was absent although the grey matter was found to be unaltered. There was abolition ol faradic irritability in the legs ascribed to oedema. SYMPTOMS. 265 extended, when near full extension the spasm suddenly comes on and completes the movement, as the blade of a pocket knife moves under the influence of the spring. Hence this has been termed " clasp- knife rigidity." Ultimately the extensor spasm may be so great that, when it occurs, both legs are rigid, and are so firmly connected with the pelvis that if one is lifted from the bed the other is moved also. This is only met with in organic disease, and is an important diagnostic indication. Parox;ysms of spasm may be brought on by any impression on the sensory nerves, a prick on the skin, or an attempt to obtain the clonus. The extreme spasm prevents any clonus being obtained, and it may be necessary to flex the limb before an attempt to obtain it is successful. As violent spasm is passing off, moreover, the tension of the muscles may alone set up a clonus, so that the paroxysm of tonic spasm passes into clonic spasm, a phenomenon that was termed by Brown-Sequard " spinal epilepsy," on account of the superficial resemblance to the sequence of spasm in an epileptic fit. This clonic spasm may often be arrested by any strong painful impression on the sensory nerves, a pinch of the skin, or painful flexion of the big toe ; the strong stimulation of the nerves of common sensation inhibits the reflex centre concerned in the clonus. There is always much weakness of the legs when there is much spasm, and there may be almost complete paralysis. Hence the condition has been termed " spastic paraplegia." It is probable that the central reflex mechanisms concerned in the production of this extensor spasm are those that subserve the act of standing. The spasm often enables a paraplegic patient to stand, when his voluntary power is quite insufficient for the act. In advanced cases the extensor spasm may be varied by attacks of flexor spasm, which at first come on chiefly during sleep, but after a time preponderate, and may ultimately be permanent ; this is always an unfavorable symptom, since, for some reason not yet understood, this flexor spasm indicates a condition of the spinal cord from which recovery is rare. Vaso-motoe and Trophic Distttebance. — Changes in Nutrition. — Considerable wasting of the muscles indicates disease of the motor tierve-cells, or of the nerve-fibres pro.ceeding from these cells. If the disease is acute there is rapid degeneration of the nerves, with the reaction of degeneration in the muscles (see p. 71). The wasting in these cases is always great, and there is always loss of reflex action. Occasionally some fibres of the nerve and muscle suffer and others do not, causing the '•' middle" or "mixed " form of reaction (see p. 32). In rare cases, in Avhich the nerve degeneration set up is of an intensely irritative character, the muscles may rapidly lose all irritability in <5onsequence of true degeneration of the fibres. I have observed this, for instance, in a growth in the lumbar region. In other cases of disease, however, there is a slighter degree of wasting of the muscles ; there is no loss of irritability in the nerves ; the irrita- bility may be slightly increased or lessened, but is changed in the 266 SPINAL CORD. same way to each form of electricity. In this condition reflex action is not lost, but, on the contrary, is often increased. The change is apparently the result of a peculiar alteration in the nutrition of the nerve-cells. It is usually the effect of an irritative degeneration of the pyramidal fibres, which influences in a peculiar manner the nutrition of the motor cells. The changes in the nutrition of the skin, if slight and chronic, resemble those produced by disease of the nerves (see p. 79), and are probably produced through the agency of the posterior roots. Per- forating ulcer and the trophic disease of joint known as " Charcot's joint " are met with especially in tabes. They also occur in syringo- myelia. Sometimes, however, these changes are most acute, Yery slight pressure, continued for a few hours, causes vesication,, and even sloughing of the skin. Sometimes bullae form where there has been no pressure. Occasionally there is inflammation of the joints. Such intense changes are only met with when the morbid process in the cord is irritative in its character, especially in haemorrhage, and in spreading or disseminated myelitis. The points on which sloughing occurs with greatest readiness are the heel, over the malleoli, the trochanters, and the sacrum. The position of the bedsores in para- plegia, usually over the sacrum, is different from that in hemiplegia, generally over the gluteal region on the paralysed side. The tendency to trophic disturbance probably favours the occurrence of cystitis from retention of urine, and the readiness with which the inflammation invades the kidneys. I have seen a low form of suppurating subperi- toneal pelvic cellulitis, in a case of disseminated myelitis with cutaneous sloughs, in which no other cause for the celluHtis could be found. Vaso-motor disturbance is common in slight degree, irrespective of the seat of the disease, but, like the trophic changes, which probably depend in some degree upon it, it is always most intense in irritative lesions of the cord. The slighter and common degree consists merely in increased warmth of the limbs, in which the vessels dilate too readily ;• while, at a later period, the limbs are colder, paler, and often livid at the extremities. In rare cases intense flushing of the skin has been observed, or copious and long-continued pei-spirafcion. When the disease is in the lower cervical region, flushing and perspiration may occur on the face and head. Disease of the cervical cord or nerves is sometimes attended by a change in the pupil, on one side only. It is due to the fact that the dilator is innervated from the cervical sympathetic through the last cervical nerves. There may be contraction, from paralysis of these radiating fibres, or there may be persistent dilatation from their irrita- tion. There may also be narrowing or enlargement of the palpebral fissure from the same cause. The cause of the double myosis, so common in some degenerative diseases of the cord, is uncertain; it is associated with loss of the light-reflex, and also of the reflex dilatation produced by stimulating the skin of the neck. SYMPTOMS. 267 The frequency of the heart's action is often permanently increased in locomotor ataxy, but we do not know by what mechanism. In disease of the cervical cord (perhaps also in that of the cervical nerve- roots) the heart may be slowed to forty, thirty, or twenty beats per minute, usually only for a time. This is frequently met with in fracture dislocation in this region. The efi'ect may perhaps be due to a loss of the influence of the nerves which, when stimulated, quicken the heart. In acute disease of the upper dorsal region the heart's action may be persistently frequent. Visceral Disturhance. — Various disturbances in the alimentary canal occur in disease of the spinal cord, and are no doubt due to the fact that the sympathetic nerves immediately controlling the canal are under the influence of the cord, and may be excited to abnormal action by its irritation, or may underact when its influence is lessened. Difficulty of deglutition is observed in some cases of acute disease of the upper cervical region. Vomiting occurs also in disease of the same part, especially in fracture of the cervical vertebrae. Constipa- tion is extremely common in disease of the cord above the lumbar enlargement. The " gastric and laryngeal crises " of tabes are espe- cially frequent in cases in which the disease is situated high up in the cord. When rectum and bladder are affected, the disease must be lower. Paralysis of the SpJiincters. — Incontinence of urine and f^ces may be due to disease of the centres that control the action of the spliinctei ani and the muscular mechanism of the bladder respectively, or it may be due merely to disease of the path (probably the pyramidal tract) through which voluntary control is exerted. In the latter case the sphincter ani acts in an automatic reflex manner, as already ex- plained. If the finger is introduced within it, the initial relaxation is felt to be succeeded by a firm tonic contraction. This proves that the anal centre in the lumbar enlargement, and the nerves proceeding from it, are intact. If this centre is destroyed, or the nerves interrupted, no tonic contraction can be felt; there is complete and persistent relaxation. I have .more than once observed a dorsal transverse myelitis arrest the voluntary influence and leave the sphincter in its condition of simple reflex action, and, a week or ten days later, the extension of the myelitis into the lumbar region, to be attended by (among other signs) perfect inaction of the sphincter. A rectal examination will then often give important information regarding the extent of the disease downwards. The sphincter of the bladder is not accessible to such direct examination, and the mechanism seems to be more complex, but we may distinguish conditions corresponding to those of the rectum. If the lumbar centre is destroyed the sphincter is permanently relaxed j urine dribbles out of the bladder as fast as it enters it; there is- simple incontinence. If there is an interruption of the voluntary- path above the centre, the sphincter may act automatically : when a ^Q8 SPINAL CORD, certain amount of urine has collected in the bladder it excites the muscular fibres in the wall to contract ; the sphincter relaxes, and the urine escapes, — there is intermittent incontinence. In this condition the mechanism is excited to action by any pressure on the bladder ; a movement, or the act of coughing, will make the urine come away. But the muscle of the wall of the bladder is indirectly under the influence of the will ; when the sphincter is voluntarily relaxed the detrusor fibres in the wall contract. Loss of voluntary power seems to lead to weakness in the wall of the bladder, so that the bladder is never perfectly emptied, and ultimately the detrusor cannot contract to expel the urine, e^an when the sphincter is relaxed. Hence reten- tion of urine occurs. When a certain degree of distension of the bladder is attained, the pressure becomes sufficient to force the urine out whenever the sphincter relaxes, and such relaxation is continually occurring under the high pressure that is repeatedly renewed in consequence of the flow from the kidneys. Hence incontinence results, — "overflow incontinence" (see p. 247). The retention often develops very gradually and insidiously when the voluntary power is only lessened ; the residual urine is at first small in amount, but gradually increases as the detrusor fails to contract adequately against the resistance. It is important, if the urine comes away involuntarily, to ascertain which form of incontinence exists ; since overflow incon- tinence, and the retention it indicates, have much graver consequences than simple incontinence. The permanent distension of the bladder constitutes a permanent hindrance to the flow of urine from the kidneys, and serious kidney disease may result. This is a not uncom- mon cause of death in spinal disease. Moreover, whenever the bladder is habitually emptied imperfectly, decomposition is apt to occur in the residual urine. The decomposition is often aided by the lessened acidity, or even actual alkalinity, of the urine. This change in the composition of the urine excites inflammation of the bladder ; pus is formed by the mucous membrane, and this, in its turn, increases the decomposition of the urine. The damage to the kidneys, by the hindrance to the flow of urine from them, may be increased by inflammation ascending the ureters from the bladder. Pyrexia. — The initial elevation of temperature in some spinal lesions may be due to them directly, but sometimes it is due to a blood- state of which the cord disease is a result. This is probably the case in polio-myelitis. The temperature is sometimes raised in dis- ease of the cord apart from the influence of morbid process. Disease of the upper cervical cord, like that of the medulla, may cause hyper- pyrexia, and this may also result from acute central lesions that occupy a considerable vertical extent, such as a central haemorrhage, although by what mechanism these act we do not know. Slight variable elevation of temperature sometimes occurs in disease of the dorsal cord, and is probably due, in some way, to the disturbance of its functions rather than to any influence of the morbid process. For SYMPTOMS. 26^ instance, in one case of hsemorrhagic myelitis witli damage from the third dorsal to the second lumbar segments, every application of electricity to the legs was followed by slight pyrexia. Convulsions. — Lastly, convulsive attacks have been known to attend the onset of acute lesions in various parts of the cord, in adults as well as in children. They are most frequent in disease of the cervical cord, but I have known a convulsion to occur in an adult at the onset of myelitis in the lower dorsal region. The convulsions are general. Their mechanism is unknown, and in some cases, especially of infan- tile polio -myelitis, they may, like the initial pyrexia, be the result of general disturbance of the system by an acute morbid blood-state. Optic neuritis has been met with, especially in connection with disease in the cervical region of the cord, and in cases in which careful examination of the brain post mortem failed to reveal any cerebral disease. Combination of Symptoms. — Certain symptoms are frequently combined, and their combination has a definite localising significance. Loss of motor power occurs in two different associations, according to the position of its cause in the motor path. It may be combined with muscular wasting, loss of electric irritability, and loss of all reflex action. In this case the disease is in the anterior cornua or nerve-roots, the lower segment of the motor path. (But the same symptoms are produced by disease of the nerves themselves — in multiple neuritis.) On the other hand, there may be no wasting, no change in irritability, and, instead of a loss of reflex action, the myo- tatic irritability is increased. The interruption of the motor path is then in the upper segment, usually in the pyramidal tracts. It may be a focal lesion of the cord, or a primary degeneration of the tracts. The distinction is that, in the latter case, there is nothing more than the muscular weakness and increased myotatic irritability. In the former case there are, or have been, indications that the lesion has extended beyond the purely motor elements. The symptoms caused by disease of the several elements of the cord have now been described, but it is necessary to consider further the combination of symptoms that results from a total transverse lesion of the cord, and from a unilateral lesion. A total transverse lesion, however limited in vertical extent, sepa- rates from the brain all parts below it, and hence, so far as will and feehng are concerned, it produces the same effect as if the whole of the cord below the lesion were destroyed. Compression of the cord in the middle of the cervical enlargement, for instance, aboHshes motion and sensation in all parts below the distribution of the cervical plexus. A transverse lesion at the second dorsal nerve causes motor and sensory palsy of the trunk and legs, leaving the arms unaffected. But the same loss, motor and sensory, results from disease which damages the whole cord up to the level indicated. Hence the extent of the motor and sensory paralysis indicates only the upward limit of the 270 SFliNAL CORD. lesion; how far it extends downwards is shown by the interference with the central and especially the reflex functions of the cord. The upward level is indicated not only by the loss of conduction, but also by the position of the girdle-pain and radiating pains, or zone of hypersesthesia, which are due to the irritation of the lowest sensory nerves in the upper portion. It is desirable to know the symptoms of impaired concliiction that occur when a transverse lesion is at different levels in the spinal cord. They may readily be ascertained by an examination of the table and figures given at pp. 250 — 252. There is, however, some uncertainty as to the effect on sensation in the limbs produced by disease at different parts of the lumbar and cervical enlargements, since, as we have seen, the exact representation of sensation in the cord is still uncertain. The upper limit of the lesion is shown by the upward extent of the motor and sensory loss. The lowest nerves supjjly the anus and peri- nseum. Those that supj^ly the sMn and muscles of the leg and foot arise from the fourth lumbar to the second sacral segments, and are damaged by a lesion involving the lower part of the lumbar enlarge- ment. In the middle of the lumbar enlargement the nerves arise which enter the lumbo-sacral cord, and these are probably destined for the flexors of the knee, and for the hip muscles supplied by the sacral plexus, the glutei, quadratus, and gemelli, and for the skin of the lower part of the gluteal region. These parts then will be para- lysed by disease in the middle of the lumbar enlargement, while the muscles and skin in front of the thigh are unaffected. The latter suffer when the disease affects the upper part of the lumbar enlargement, the origin of the anterior crural (rectus, &c.), and obturator (adductors). The skin on the upper and outer parts of the thigh loses sensibility, with the part adjacent to the scrotum, and in the groin, only when the disease damages the highest part of the lumbar enlargement, from which the second and third lumbar nerves arise, and then the flexors of the hip become paralysed. In proportion as the disease is higher in the dorsal region we have the symptoms ascending higher up the trunk, and marking accurately the height of the lesion by the loss of cutaneous sensibility, and by the impairment, first of the abdominal muscles, and then of the in- tercostal muscles. The umbilicus corresponds to the tenth dorsal nerves, and the ensiform area to the sixth and seventh. When the disease reaches the lowest part of the cervical enlargement (the first dorsal nerves) we have the first symptoms in the upper extremity ; but these are not, as might be expected, in the muscles moving the shoulder-joint, but in the hand. The first numbness is complained of in the little finger, and the first weakness is in the intrinsic muscles of the hand. Ascending higher, the symptoms pass up the arm with some uniformity, and without respect to nerve distribution. When the middle of the cervical enlargement is reached (the fifth, sixth, and seventh cervical) the shoulder muscles and the serratus magnus be- SYMPTOMS. 271 €ome paralysed, and there is general loss of power and sensation. (Tot details see table, p. 252, and also pp. 250 and 251.) AboTe the level ol the sixth pair the trapezius and stemo-mastoid become somewhat weakened, for the fibres of the spinal accessory which supply them un- doubtedly arise in part from this region of the cord. At the fourth and fifth cervical the lower part of the neck becomes anaesthetic, and the diaphi-agm ceases to act. Here our localisation might cease, for total transverse lesions at this spot necessarily cause death. For a little time the sterno-mastoids and scaleni can stiU get some air into the chest, rarely in sufficient amount to maintain life for more than a few days. But limited lesions may occur higher up, and then we have complete powerlessness of the muscles moving the head, upper part of trapezius and sterno -mastoid, and other muscles attached to the occipital bone, and interference with sensation in the neck and parts of the head, which are not supplied by the fifth nerve. The extent downwards of the lesion, its vertical extent, is thus not indicated by the impairment of the conducting functions, by the motor or sensory paralysis ; to ascertain it we have to examine the functions of the cord as a central organ, and to ascertain how far they are impaired in the paralysed region — to examine especially muscular nutrition and reflex action. The state of muscular nutrition and irritability indicates how far the anterior cornua are injured. The relation of the several groaps of muscles to the cord is shown in the first column of the table. The integrity of reflex action indicates the integrity of the reflex loops, and the study of the superficial reflexes of the trunk is especially instructive in this respect. The series of reflexes, and the relation of each to the cord, are shown in the second column of the table ; the muscle-reflex contractions are piinted in italics in the position which corresponds to the centres and nerve-roots which are essential for their production. Excess of superficial reflex action indi- cates loss of the cerebral control exerted on the reflex centres, and con- siderable excess of the muscle-reflexes implies impaired function of the lowest part of the pyramidal tracts, and generally shows the existence of a descending degeneration in. the lateral columns. Keflex action in the legs may be abolished for a few hours by acute disease or injury above the lumbar enlargement, ia consequence of inhibitoiy shock, but soon returns if the lumbar centres are intact. As already explained (p. 264), if there is no return of reflex action or myotatic irritability, their absence shows that the lumbar region is involved in the primary lesion ; secondary extension to this is indicated by loss of reflex action distinctly subsequent to the onset. If such loss occurs vdthout wasting and loss of faradic iiritability in the muscles, it shows that the disease in the lumbar region is limited to the posterior columns or cornua.* • A few cases have been met with in which a transverse lesion of the dorsal cord, esp'i'ially a transvi-rse concussion- myelitis, without post-mortem signs of lumbar inllainmation, has caused a persistent loss of reflex aetJon m the legs. In 272 SPIJSIAL CORD. The fact of chief importance is that dorsal cord disease, the most common form, causes no persistent loss of reflex action in the legs, and that for such loss special causes must be sought. Unilateral lesions interrupt the motor path to the muscles on the same side as the lesion, causing one-sided palsy, termed " spinal hemi- plegia " when the disease is so high as to affect both arm and leg, " hemiparaplegia " when it is lower, and affects one leg only. There is often some loss of power on the opposite side, which may be due either to slighter damage to the other side of the cord (since few lesions are strictly unilateral) or to damage to non-decussating fibres. Conversely, the paralysis of the leg may be incomplete when that of the arm is complete, owing to the escape of the fibres for the leg which cross lower down the cord. Sensation is affected on the opposite side, but not quite up to the level of the lesion, because the decussation of the sensory tract is not immediate, but occurs somewhat above the entrance of the nerves. The upper level may vary for different forms of sensibility, in consequence probably of the level of crossing (in rela- tion to entrance) being different for the several paths. A lesion in one side of the lumbar enlargement often affects sensation on the same side as motion, because it damages the sensory path before it has crossed. In all cases of crossed motor and sensory paralysis the sensibility of the muscles differs from the other forms of sensibility ; and if it is affected on one side, this is the side of the motor palsy, and not of the cutaneous ansesthesia.* The crossed affection of cutaneous sensibility may involve aU forms of sensation or only some of them. Sensibility to pain is almost in- these cases, however, there has been not only loss of the muscle-reflex action, but also of the skin reflexes, a clear indication of an exceptional condition. Moreover there has also in other cases been loss of faradic irritability and rapid muscular wastino:,^in short, there have been all the indications of a lumbar myelitis. The most probable explanation of these cases is that the descending degeneration of the pyramidal tract has been more than usually irritative in nature, so as practically to amount to a parenchymatous inflammation, and that this has invaded the motor structures as a nutritional change, sufficient to abolish their function, without, however, destroy- ing their form. In one such case it was noted that the lumbar nerve elements were extremely granular in aspect. For a different explanation of these cases see Bastian, 'Med.-Chir. Trans.,' 1890; Bruns, ' Neurol. Centralb.,' 1895, and • Arch, f. Psych.,* XXV ; and Egger, ' Arch. f. Psychiat.,* xxvii ; see also note, p. 264. * This was first pointed out by Brown-Sequard in his important study of these cases. Scepticism has been expressed as to tlie fact, based on a denial that the test commonly employed, recognition of posture, is significant. Experiments on animals, even monkeys, are inconclusive, but the evidence from cases in man is very strong, not only of the occurrence of the loss, but of the significance of the test. In some cases, moreover, the muscles were insensitive to pressure. One recorded instance is the following : — A stab in the dorsal region caused loss of cutaneous sen- sibility in the right leg and motor palsy in the left. On the left side, on which cutaneous sensibility was normal, the sense of posture was absolutely lost, while it was present on the right side, on which cutaneous sensibility was impaired. The patient often thought the left leg was flexed when it was extended. Ultimately this leg presented distinct ataxy. (Gilbert, 'Arch, de Nevrologie,' 1882, p. 275.) SYMPTOMS. 273 variably impaired. The temperature sense is usually affected witli that for pain; in only two of twenty recorded cases (in which the affection of sensibility was carefully noted) was the sense of tempera- ture normal, and that of pain impaired, and in neither of these cases was the sensibility to pain actually lost. On the other hand, in one , third of the cases tactile sensibility was unaffected, and in about one tenth of the cases it was impaired on both sides. Cutaneous sensibility is sometimes impaired in a zone at the level of the lesion, and on the same side, in consequence of the damage to the nerve-roots entering the cord, and above this there may be a narrow band of hypersesthesia from irritation of the roots at the upper part of the lesion. On the side of the lesion, below the anaes- thetic zone, there is, in most cases, a remarkable hypersesthesia, corre- sponding in distribution with the anaesthesia on the opposite side. Painful impressions are felt most acutely, and even a touch on the sMn, or warm or cold bodies, produce pain. The cause of this hypersesthesia is obscure. Both it and the opposite loss of sensibility may last for twenty years, and it cannot be ascribed therefore to any irritation by the morbid process. It is perhaps due to an altered action of the cerebral centres on the opposite side of the brain. There is much evidence of an intimate connection between the sensory centres on the two sides, and it is conceivable that the altered func- tional state of the centre pn the side of the lesion, to which impressions cease to come, may induce in the opposite hemisphere a condition expressed as hypersesthesia. The condition may be thought of in relation to the peculiar phenomena of transfer in hysterical hemi- ansesthesia. Eeflex action is increased in all its forms on the side of the lesion, but the increase only occurs after some days. At first it is lessened or even abolished, no doubt from the inhibitory influence of the irritation of the morbid process. The side below the lesion is at first, for some days or even weeks, warmer than the other, the difference being usually about a degree Fahrenheit. In the course of time this difference passes away, and the side may even be colder than the other. These symptoms may be shown in the form of a table : Zone of cut. hypersesthesia. -^— — — ansesthesia. Motor palsy. Hypersesthesia of skin. Muscular sense impaired. Bi^flex action first lessened, then increased. Temperature raised. VOL. I. LESION. I Muscular power nornnal. Loss of sensibility of skin. Muscular sense normal. Beflex action normal. Temperature same as that above lesion. 18 274 SPINAL COED. The vertical distribution of tlie symptoms varies according to the vertical position of the lesion. Their relations are best marked when the lesion is in the dorsal region of the spinal cord. When it is in the cervical or lumbar enlargement the upper limit is less distinct because of the complex representation of skin and muscle in the nerve-roots. GENEBAL PATEOLOQT AND ETIOLOGY: INDICATIONS OF THE NATURE OF TEE LESION: FATSOLOgHCAL DIAGNOSIS. The kinds of disease to which the spinal cord is liable are not specifically numerous, but those which are common present several varieties. The processes are congestion and anaemia, haemorrhage, inflammation, degeneration, and growths. Haemorrhage and growths are, on the whole, rare. Congestion plays an uncertain part in the production of symptoms ; its influence has been certainly overrated by some writers, and perhaps under-estimated by others. Anaemia is now known to be sometimes associated with certain definite changes in the spinal cord, and it is possible that it may occa- sionally give rise to symptoms without producing gross disease. The most frequent lesions are inflammation and degeneration. These two processes, distinct in their typical forms, blend in their intermediate varieties. Inflammation varies much in character and course. Its effects are in some cases produced with great rapidity, in other cases with extreme slowness. It probably commences in most instances outside the nerve-elements, which are secondarily involved. Perhaps some acute processes in the nerve-elements themselves are most accu- rately regarded as a parenchymatous inflammation, analogous to that which we know occurs in the fibres of the peripheral nerves. Degene- ration consists of two processes, a wasting of the nerve-structures, cells and fibres, and an overgrowth of the connective-tissue elements. The latter leads to the condition termed sclerosis. The name has been given to it, apparently, because the process is one that, in other organs, increases their consistence. In the cord it has not often this effect. The newly formed connective tissue is rarely of greater firm- ness, and is often less firm, than the nerve-elements it replaces. In sclerosis, however, we must distinguish two types. In one the process is limited to structures that have the same function ; the process begins as a degeneration of the nerve-elements, and the overgrowth •of the connective tissue is a consequence of their wasting— the affection is essentially " parenchymatous." The so-called "secondary degene- rations " are of this character ; but similar changes are often primary, and affect the structures that have the same function, often through a considerable extent of the cord. Hence they are termed " system diseases." In the other type the morbid changes are not distributed PATHOLOGICAL DIAGNOSIS. 275 according to function. Tliey are apparently random in incidence, and involve adjacent structures in consequence of contiguity. These begin in the connective tissue and not in the nerve-elements, which suffer secondarily. They are essentially interstitial processes. Insular sclerosis is an example of this type. The position of the islets of sclerosis has no relation to the function of the parts, and may involve parts of adjacent structures that have no common func- tion. Areas of difEuse sclerosis are also met with which have not the sharp limitation of the insular form, and are regarded by some as of the nature of chi'onic sclerotic inflammation. If such a lesion is so situated as to involve fibres that undergo secondary degeneration, this necessarily results when the damage to the fibres is sufficiently great. We have then a combination of the random and systemic forms of sclerosis, but one that has no real pathological significance. There are, however, other relations between the two types that deserve attention. These will be considered in connection with the special morbid processes that present them, but a brief mention of them here may make some facts of other diseases more intelligible. The process of secondary degeneration and secondary sclerosis varies in its character, presenting in some oases a greater amount of vascular disturbance than in othera. It seems to partake of the character of the lesion causing it, as we have seen (p. 73) the process of secondary degeneration in the nerves may do. The same difference is seen in the primary degenerations, such as occur in tabes. This difference is analogous to that which, as already described, occurs in some varieties of multiple neuritis. We can indeed see the difference in the eye : tabetic optic nerve atrophy, in most cases, presents no sign of inflammation, while in othei-s the early stage may be accompanied by distinct slight neuritis, to be seen with the ophthalmoscope. Secondly, the chronic inflammations, with the diffuse limitation, extending to adjaicent structures irrespective of function, have yet sometimes a marked tendency to be localised in structures of definite function. Thus there is sometimes diffuse sclerosis of the lateral pyramidal tracts and posterior median columns, not sharply limited to these, and yet with a correspondence and symmetry not to be overlooked. Thus the two processes tend to meet ; the systemic degeneration or sclerosis to be diffuse ; the difEuse inflammation or sclerosis to be systemic ; and it is sometimes not easy to say, from mere microscopic examination, to which class a lesion belongs. Lastly, there is a curious fact, which has been strangely overlooked although attention was first called to it by Charcot — that inflammation may extend from a primary lesion along a tract that undergoes secondary degeneration, but in the opposite direction to that of the degeneration. It is very common for the inflammation at a given place in the cord, especially that due to compression, to extend farthest along certain tracts, irrespective of their secondary degeneration, and in some cases this extension occurs through a con- siderable extent of the cord. An ascending inflammation limited to the pyra- midal tracts may, for instance, be traced through several segments. The fact suggests that the neuroglial elements may share to some extent a difference that obtains between the fibres of different tracts, and it may easily lead, and probably has led, to erroneous conclusions. Softening of the spinal cord is very common. Whenever the nerve- fibres are broken up into disconnected globules of myelin, separated 276 SPINAL CORD. bj serum in a sort of emulsion, tlie consistence of the part is necea- sarily lessened. Acute inflammation always causes such a breaking up of the nerve-fibres, and hence inflammation always causes softening as its first effect. The separate particles are augmented by leucocytes, which escape abundantly into the tissue. Ultimately connective-tissue elements are formed, which increase the consistence, it may be up to, . and even beyond, the normal degree. In a very chronic inflammation the formation of new tissue may proceed pari passu with the destruc- tive process, and there may be at no time much diminution of consistence. It is in these cases that it is difficult to draw the line between inflammation and degeneration. Does such softening of the cord occur apart from inflammation ? The question is not easy to answer. In the brain necrotic softening is very common as a consequence of arterial obstruction — is indeed the common form of softening. But in the spinal cord we have no such distinct evidence of the occurrence of necrotic softening. If embolism occurs, it is excessively rare. The course of the vessels does not favour the passage of a plug into them, while the vertical connection in the anterior spinal and anastomotic arteries (see p. 227) will prevent damage from obstruction in the central system unless this is situated in the terminal vessels of the grey matter. Arterial thrombosis, due to atheroma of the walls of the vessels, such as is so common in the brain, probably does not occur in the cord. The arteries are smaller than those in which atheroma is met with in the brain, and the low- ness of the blood-pressure within them involves the absence of the chief cause of atheroma. It is likely that spontaneous thrombosis occurring in vessels affected with syphilitic endarteritis sometimes sets up the changes that are now regarded as those of primary inflamma- tion; and such a lesion has actually been met with, but we have no evidence of its frequency.* Besides the morbid processes to which the cord itself is liable, it suffers also in consequence of disease outside it. It may be com- pressed by growths springing from the membranes or bones, and by products of inflammation within the spinal canal. Compression not only causes degeneration of the nerve-elements, but usually excites actual inflammation. This " compression-myelitis " may attain a degree and an acuteness out of all proportion to the causal compres- sion. The membranes may be the seat of haemorrhage which com- presses the cord, or inflammation which irritates it, even when the organ is not invaded in appreciable degree. The series of recognised lesions of the spinal cord, obvious or micro- scopic, does not by any means exhaust the list of its morbid states. Changes may occur in the nutrition of its elements interfering with their function, which are, and are likely to remain, altogether beyond our means of detection. Such morbid states are often called " func- tional diseases," but when prolonged they are probably more accurately • Williamson, • Lancet,' 1894. PATHOLOGICAL DIAGNOSIS. 277 -conceived as nutritional diseases (see p. 1). Deiangemeuts of function that we can regard as purely such are few and rare. But disturbances of function may be due to organic disease in some other part of the nervous system, and they may also be the result of toxic iigents. Lastly, functional action in all organs is attended with increased blood-supply ; and when excessive, the vascular disturbance may go on to a condition indistinguishable from inflammation, with escape of leuco- cytes, &c. The prolonged experimental stimulation of sensory nerves has actually produced myelitis in the related portion of the cord. In connection with the general pathology of diseases of the spinal cord, it is important to note certain general facts of their causation : — (1) Neuropathic disposition. — An inherited tendency to disease of the nerve-elements, manifested by such affections as epilepsy and insanity. This cause is chiefly influential in producing the structural and nutritional diseases, beginning in the nerve-elements, and especially, among structural diseases, the " system-degenerations," as they are called. (2) Prolonged mental distress sometimes sets up degenerative changes in some elements of the cord, especially in persons who are predisposed by (1). (3) Injury. — A severe concussion of the cord may cause (a) instant grave damage, usually haemorrhage. Or (b) it may cause no immediate effect, but symptoms may come on at the end of a few days and progress slowly or rapidly. Such symptoms are usually due to inflammation, secondary to minute spots of injury, too small to cause direct symptoms. Lastly, (c) the concussion sometimes seems to pervert the process of nutrition in the nerve- elements. Slow symptoms of impaired function may result, and these may progress until, after months or years, there is actual structural disease. Similar effects, especially the graver varieties, are met with as a result of lessened atmospheric pressure in divers and workers in caissons. (4) Exposure to cold. — Wet cold is especially effective. The most frequent effect of a severe exposure is acute inflammation, but habitual exposure may produce chronic inflamma- tion, or degenerative disease. The exposure that is effective may be general, or chiefly of the feet and legs, occasionally of the back. (5) The spinal cord appears also to be the seat of primary infection as in epidemic cerebro-spinal meningitis, tetanus, and possibly acute anterior polio-myelitis. (6) Toxic agents that can act on the cord are numerous, and are seen in alcoholism and lathyrism. (7) Other diseases may also induce morbid changes in the spinal cord. The primary malady may be an acute specific disease, or some more obscure blood-state, the precise nature and relations of which are still undecided. It is probable that certain blood-states due to an organ- ised virus excite some forms of inflammation of the cord and of its membranes, just as it may cause inflammation of the peripheral nerves. Septicaemia may excite meningitis, or even abscess of the cord itself. Tubercle is common on the m.embranes, but seldom produces iniiam- 278 SFINAL CORD. mation. Diphtheria may cause acute clianges in the nerve-cells and nerve-roots. Gonorrhoea * has produced myelitis, and such diseases as variola, typhus, &c., have been followed by cord inflammation. Syphilis is a very frequent cause of disease, and may act in several ways. The demonstrated mechanisms are (a) by a syphilitic growth compressing or invading the cord, (6) by changes in the cord resulting from thrombosis occurring in diseased vessels, and (c) by chronic syphihtic meningitis, damaging the cord and the nerve-roots. But (d) acute and chronic inflammations of the cord are often met with in syphilitic subjects, and have been thought to be, in many instances, of syphilitic origin. It is doubtftd whether they present any syphilitic characters, i. e. any histological features by which they differ from non- syphilitic inflammations. The evidence of dependence on syphilis is stronger in the case of chronic and subacute disseminated inflammation than in the case of acute myelitis. It may be, however, that inflammations due to other causes, e. g. exposure, run a more acute course when they affect syphilitic subjects. The part thus played by syphilis in lessening the resisting j)ower of the organism may be shared by other factors, such as malnutrition and excesses of various kinds. Lastly, (e) certain degenerative diseases of the cord are very commonly preceded by syphilis ; one of them, locomotor ataxy, so frequently that a causal relation between the two can scarcely be doubted. But these degenerative diseases are certainly not syphilitic in nature ; they differ in no respect from the similar morbid processes that occur in individuals who have not had syphilis, and are probably the consequence of some toxin left behind by the morbid agency to which the constitutional malady is due. (8) Excessive muscular exertion has been held to play a part in the generation of chronic disease of the cord. This view has of late derived some support from experiments iipon animals. t (9) Pathological changes in the cord are known to result from the amputation of limbs. These have, however, no clinical significance. The outline just given of the general pathology and etiology of diseases of the spinal cord wiU enable us to consider the last element in diagnosis, the nature of the lesion. The seat of the disease is indicated by the combination of symptoms; its nature can only be determined by considering, separately and together, several other points : — (1) The way in which the symptoms came on. (2) The causes that can be traced, taken in conjimction with the known effects of those causes. (3) The seat of the disease, taken in conjunction with the known liability of certain structures to certain lesions. The most important of these elements is the mode of onset, and the other indications should only be used in strict subordination to this. * Gowers, ' Clinical Lectures on Neivous Diseases,' p. 119 ; also Leyden and Goldscheider, ' Die Erkrankungen des Riickeniuarkes,' p. 369. t Independently by O. Rosenbach and Edinger (see Edinger and Helbing,. ' Verhandlungen des 16 Cong, f . inner. Med.,' Wiesbaden, 1898). PATHOLOGICAL DIAGNOSIS. 279 The time occupied by the onset of the disease is thus the first element in the pathological diagnosis. By " time of onset " is meant the period that elapses between the actual commencement of the symptoms and their attainment of a considerable degree of intensity. We may divide the chief modes of onset into five classes, and classify the most common lesions in relation to them, in the following table : DiSBASB. Onset. Disease. Sudden T (few minutes) [ ^^ i i • J . ' avascular I0S10U8. Acute I (few hours or days) J ~) r Subacute | I (one to six weeks) i» Inflammation, Pressure and J Suhchronic J growths } (six weeks to six months) J "1 Chronic i- Degeneration, [_ (more than six months) J A lesion of sudden occurrence, the symptoms developing in the course of a few minutes, is almost always vascular, commonly haemor- rhage, sometimes perhaps vascular obstruction. But a vascular lesion may occupy a somewhat longer time in development — a few hours or days. In acute and subacute inflammation the symptoms come on in the course of a few hours, a few days, or a few weeks. Subacute and chronic inflammation occupies from a few weeks to a few months. Degeneration, in which there is no adequate evidence of any inflam- matory process, occupies many months, or it may be years. The sym- ptoms produced by tumours which invade or compress, and by simple pressure (traumatic causes excluded), are never sudden or very acute, and rarely very chronic ; the time occupied by the development of tho symptoms varying, according to the nature of the cause, from a fort- night to six months. It is necessary to consider, however, not merely the whole time occupied by the development of the disease, but also the uniformity of its course. Two or more morbid processes may concur. An initial myelitis, for instance, may lead to a secondary degeneration ; and on the other hand, in degenerated tissues, sudden vascular lesions oc- casionally occur. Pressure produces local myelitis, which may be independent of the pressure in its development, and have an acute or subacute onset. The whole course of the disease must be ascertained before an inference is drawn, and the possibility of a double process must always be kept in view. The onset and course of the symptoms thus sometimes enable us to decide at once that a lesion is of a given character, as that one which occurs instantly is vascular, or that one which takes years for its development is degenerative. More frequently they enable us to exclude certain morbid processes, and to restrict the possible lesion to two or three forms. For instance, a lesion which comes on in the 280 SPINAL CORD. course of a few hours must be either vascular or inflammatoryc Between these we have to decide by attention to other indications. In actual diagnosis it is convenient to consider next the indication afforded by the position and distribution of the disease. We consider what diseases occur in this situation, and then which of them have the mode of onset that has been ascertained. Th^s indication involves a knowledge of the various diseases and their seat The most important consideration is that a wide range of symptoms jf uniform character indicates the affection of a definite system of structure, and in most instances a disease commencing in the nerve-elements, and if the onset be chronic we may feel sure that it is a degeneration. On the other hand, the involvement of many functions suggests a random process, such as inflammation or pressure. But this indication is always to be subordinated to the mode of onset. Thus the limitation to a single structure does not exclude inflammation : this may affect, for instance, the anterior grey matter only, and cause corresponding symptoms. The symptoms may indicate a morbid process limited to one half of the cord, but this does not materially modify the diagnostic method. Almost any process may, in rare cases, be thus limited. System degenerations and acute inflammations are least frequently unilateral, and they never reach a considerable degree of intensity on one side without some affection of the other side On the other hand, tumours and foci of chronic myelitis are often one-sided, and still more often affect one half of the cord first and then the other. Indication of disease outside the cord, irritation of certain nerve- roots, causing severe local pain, often precedes the symptoms of com- pression, and is an important aid to diagnosis. It shows the existence of a morbid process outside the cord before the cord is involved. But we cannot use even this indication except in dependence on the mode of onset. A disease, as a growth outside the cord, may, as we have seen, not only compress the cord, and cause slow loss of power ; it may excite inflammation and cause rapid palsy. The last element in the pathological diagnosis is the detection of any influence which can be regarded as the cause of the disease in the spinal cord, or any associated condition which may indicate an active morbid process. We have seen that the mode of onset may help us to limit the disease to certain possible forms of lesion ; the distribu- tion of the affection may render it probable that it is one or other of these forms ; and the detection of a cause and the knowledge of the lesion which that cause produces may help us to carry the diagnosis still further. The most important general causes of disease of the cord, and the processes to which they chiefly give rise, have been already mentioned. The causal element in diagnosis is chiefly an application of those facts. The morbid process outside the spinal cord that most closely simu- lates its disease is, unquestionably, parenchymatous multiple neuritis. INJURIES OF THE SPINE. 281 The diagnosis depends on a tliorougli knowledge of the varied sym- ptoms of the latter, since its elements vary according to the different manifestations of the disease of the nerves. For these, and for any general diagnostic principles, the reader is referred to the account of that disease. The only sure ground for diagnosis is a thorough knowledge of the various morbid processes and their symptoms ; and the only safe plan is to work by these, from symptom to seat and onset to nature, treating every case as a problem to be worked out to a definite diagnosis, and only then comparing the result with the types of disease. To one of these the case may or may not conform ; if it does not, the comparison with types as a means of diagnosis will only leave the observer stranded and powerless. The distinction of functional and nutritional disease from organic lesions may conveniently be postponed until the symptoms of the former are specially described. SPECIAL DISEASES OF THE SPINAL CORD. DISEASES OF THE VEBTEBBAL COLUMN. Diseases of the bones of the spine fall for the most part within the province of surgery. But there are few of these diseases that do not, among their most frequent effects, interfere with the functions of the spinal cord. Hence an account of the diseases of the cord would be incomplete without some mention of the morbid states that begin in its bony case. INJURIES OF THE SPINE. Injuries to the spinal column may consist of punctured wounds (which need not be considered here), concussion (the effects of which on the cord will be considered later), and fracture or dislocation of the vertebrae. It may, however, be useful briefly to describe the more salient features of the last two conditions, their relation to the damage the cord sustains, and the symptoms thus produced. Dislocation. Simple dislocation occurs in the cervical region, most frequently at the fifth and sixth vertebrae. It may take place gradually or suddenly: gradual displacement is always secondary to disease of the bones; 282 SPINAL COliD. mdden displacement may occur in disease or from injury. The damage to the cord is always greatest in traumatic displacement of healthy bones, because the force needed to produce the dislocation ia much greater, the displacement is more considerable, and the effect on the canal and the contained cord is greater. Displacement may occur in any direction : it usually iuYolves both vertebral articulations, but, in rare cases, it is oblique, involving one articulation only. The common causes are violent blows or falls on the head, rarely sudden rotation of the head while a weight is carried upon it. The symptoms are a lateral or forward or backward displacement of the head, so that the chin is in contact with the shoulder or the chest, or the occiput with the nape of the neck. There is also irregularity of the vertebral spines, usually readily detected. The cord is damaged in most cases, and the symptoms are those of a total transverse lesion in the situation of the luxation. It may be merely compressed, especially in cases of disease, in which the displacement has occurred with little force. The symptoms of paralysis have been known to pass away, in such a case, on the reduction of the dislocation. More commonly the cord is also bruised, with extravasation of blood, and secondary myelitis occurs later. In such cases, if the patients live, there may be anaesthesia or hyperaesthesia below the lesion, with total paralysis of the limbs, and excess of reflex action. In rare instances the cord has been completely divided. In still rarer instances of slight displacement it has not been injured. Rupture of the transverse ligament which retains the odontoid process may permit the latter to compress the cord, and thus to cause instant death. This often results from sudden suspension by the head, as in crimir.%xl executions. One of the curiosities of surgical literature is a case related by Petit in which a man, playing with a neighbour's child, lifted it up by the head, and caused instant death by rupturing the transverse ligament. The father of the child, entering at the moment, stabbed the man with a knife, the blade of which passed in between the first and second cervical vertebrae, divided the spinal cord, and the man also fell dead. Rupture of the ligament has also resulted from raisiag a heavy weight with the head. The treatment of dislocation is too purely surgical to be described here. Fractttre. All organic diseases of the bones, weakening them, predispose to fracture. Among these, one is of special medical interest ; the ver- tebrae, especially in the lumbar region, may share the rarefaction and weakening of the osseous tissues occasionally produced in tabes, and then a very slight traumatic influence, a blow or wrench, may cause fracture. The force needed is often so slight as to fail to cause dis- placement or other symptoms except local pain, and symptoms may only supervene at a somewhat later date. Apart from disease, the INJUEIES OP THE SPINE. 28S accident is most common in adults, tlie greater elasticity of the verte- bral column in children giving to them a comparative immunity. Its cause is a blow or fall on the spLae, or sudden forcible flexion. In extremely rare cases a fracture, "dually slight, has resulted from severe muscular exertion. This i an importanb fact, showing that muscular exertion may injure the spine, and may lead to symptoms at a later date. Symptoms of such injury, in slight degree, are not uncommon. Fracture may occur at any part of the spine, but is most frequent at the fifth or sixth cervical, and at the last dorsal or first lumbar vertebrse. In the dorsal and lumbar regions the bodies are broken in two thirds of the cases, but in the cervical region the arches alone are fractured in one half. Usually there is a displacement of the vertebral column at the seat of fracture. Earely the bodies may be crushed without displacement. The displacement of the bone involves a narrowing of the canal and, usually, compression of the cord. This may also result when the arches only are driven in. But the cord may be seriously damaged when there is no permanent narrowing of the canal, as in Figs. 89 and 90. The dura mater is rarely torn except <^ Pig. 89. — Frac hi re of the first lumbar vertebra. DM. Dura mater. There was no perniiuit^nt narrowing of the canal, but, nevertheless, the spinal cord was greatly damaged at the spot; see next figure. bj a splinter. Blood is almost always extravasated outside the dura mater, often in considerable quantity, from the rupture of the large veins in this situation. There are usually only small extravasations in the pia mater. The cord is, in most cases, bruised and compressed by the lower fragment (Fig. 91). Sometimes it is flattened, and it may even be divided, all nerve- substance being squeezed out of the pia-matral sheath at the spot. In the case shown in Figs. 89 and 90 the cord appeared to have been split longitudinally at the spot, perhaps by the mere force of the concussion. It is very common to have local myelitis, opposite the fracture, without any permanent narrowing of the canal or compression of the cord j the inflammation seems to be 284 SPINAL CORD. tlie direct result of tlie concussion. Blood may be extravasated into tlie bruised part, sometimes in minute spots, sometimes in larger haemorrliages, and even into tbe central canal. These changes are usually limited to the spot directly damaged, but secondary myelitis may be set up, and sometimes extends beyond the contused area. It Ft a. 90. Fig. 91. I Fia. 90. — Spinal cord damaged by the fracture shown in Pig. 89. The elements of the cord itself are cbano^ed beyond the possibility of identification. The ascending degeneration is shown in Fig. 76. Pig-. 91. — Fracture of tlie body of the fifth dorsal vertebra and of its processes. (After Gurlt.) may even extend through the whole length of the cord below the injury, and then its central functions are abolished. In cases of some duration the usual ascending and descending secondary dege- nerations are also found. It is important to note, moreover, that the secondary degenerations have sometimes the irritative character already described (p. 272, note), and that an ascending inflammation may for a short distance above the lesion be limited to a tract that degenerates downwards (see p. 275). Fig. *1^, p. 214, represents sections of the cord from the case of fracture figured above. Occa- sionally the injury leads to secondary caries of the bone, with all its consequences. Symptoms. — Three classes of symptoms result. (1) The local indica- tions of the injury to the spine. (2) There may be certain nervous symptoms not distinctly due to the damage to the cord. One of these is general shock, which may be so great as to entail transient loss of consciousness. Vomiting occasionally occurs. There is great pain in the position of the fracture, rendered very intense by pressure, and often radiating along the nerves which come from this part, the roots of which are compressed. In rare cases epileptiform con- vulsions have followed fracture, usually at an interval of some days. (3) Symptoms which result from the damage to the cord, and con- sist in paralysis of the parts below the injury. Its character depends INJUEIES OF THE SPINE. 285 on the amount of damage. If' this is considerable, there is both motor and sensory paralysis up to the level of the lesion, with loss of power over the sphincters. Reflex action is lost at the level of the lesion, and the examination of the trunk- reflexes often gives important information regarding the extent of the damage, when this is in the dorsal region. Below, reflex action is usually diminished or lost, probably because the centres are impaired by descending myelitis. Spasmodic twitchings sometimes occur in the limbs immediately after the injury, and priapism is the rule, especially if the lesion is cervical. The pains are severe in the arms when the fracture is opposite the cervical enlargement, and in the legs when at or below the lumbar enlargement, so as to damage the nerve-roots. In these cases there may be rapid wasting of the muscles, with loss of electric irritability. There is usually at first incontinence, afterwards retention of urine, but the former is persistent if the lumbar centres are damaged. Cystitis, bedsores, &c., may supervene. ITltimately, if the damage is above the lumbar enlargement and the patient lives, there may be increased myotatic irritability in the limbs, progressing to spasm, so that spastic paraplegia results. In many cases in which the knee-jerk is at first lost it may be months, or even years, before it returns. Special symptoms result when the injury is in certain parts of the spine. Fracture of the first two cervical vertebrae causes instant death, , unless the displacement is very slight, and even then there is imminent danger of further displacement, with the most serious consequences, on any incautious voluntary movement. With slight displacement persons have been known to live for weeks, and then die from secon- dary myelitis ; they have even recovered altogether. Now and then there is no compression of the cord, although there is distinct displace- ment, even sufficient to be recognised in the pharynx (Ley den). In such a case death has resulted at a later period from caries. The characteristic symptoms are local pain, increased by all movements (which are rendered almost impossible), displacement, and spinal symptoms. The latter may be slight — merely difficulty in breathing or swallowing — or considerable, and involving the trunk and limbs. Sometimes there is hyperpyrexia. Not more than one case in fifty recovers. Middle Cervical Vertehrse. — The third, fourth, and fifth vertebrae are most frequently fractured. When the injury to the cord is consider- able, death usually occurs very rapidly, because the roots of the phrenic nerve are involved, the intercostals being necessarily paralysed with the parts below. In some cases there is little immediate displacement, and the symptoms are slight until further displacement occurs in some movement. Thus a man who had met with an injury of this kind went to be shaved ; during the proceeding, his head was turned on one side by the barber, with the unexpected restilt of causing dis- placement of the fracture, and immediate death. When the fracture is at the cervico-dorsal region, opposite the lower part of the cervical 286 DISEASES OF THE SPINE. enlargement, tlie arms frequently escape at first, tlie early paralysis being confined to the legs and muscles of the trunk. Respiration is diaphragmatic only. After a few days the arms become involved, but theii- paralysis is often partial, affecting, for instance, only certain muscles, as the extensors of the hand, and it is often accompanied by local spasmodic movements. Movements and pressure cause pain, and there is local muscular rigidity. The head may be in normal or in abnormal position. Yaso-motor disturbance in the face and general hyperpyrexia have been observed. There is not unfrequently altera- tion in the joints, especially the knee-joints, apparently the result of the presence of fluid in them. In fracture of the dorsal vertebrae (2 — 11) the arms escape, the legd are paralysed, and the trunk-muscles up to the height of the lesion. The pain in the trunk may be very severe. There is hyperesthesia or anaesthesia in the parts below. The reflex action in the legs is exces- sive ; that in the trunk is abolished at the level of the lesion. The last dorsal and first lumbar vertebrse are fractured more frequently than the others, and there result paralysis of the legs, complete or irregular, severe pains, tingling, &c., sometimes followed by hyper- sesthesia or loss of sensibility, and by rapid disturbance of nutrition, in both the muscles and the skin. In fracture of the lower lumbar vertebrse the symptoms are often slight ; below the extremity of the cord the nerves occupy a smaller space in the canal, and so may escape compression by a moderate displacement. If they suffer, the fractured vertebrse unite very slowly. A false joint is occasionally formed. Secondary myelitis and its consequences are frequent causes of death at a variable period after the injury. CAEIES OF THE SPINE. Caries of the bones of the spine is a frequent cause of paraplegia. It is often termed "Pott's disease," from the English surgeon, Percival Pott, who first described it (in 1779) as a cause of paralysis. Causes. — Males are said to be rather more liable than females, but the difference in sexual incidence is not great. It is more common in childhood (after three), and next in early adult life, but it may occur at any age, and is perhaps more common in the second half of life than any other scrofulous lesion. I have known it commence at fifty, and it has been met with as late as seventy. It is distinctly a manifesta- tion of the tubercular and scrofulous diathesis, and evidence of such inheritance is to be traced in most cases. Occasionally the sufferer himself presents such indications, e. g. lung disease, or caries of other bones. It occasionally develops simultaneously with other signs of acute general tuberculosis. Injuries seem frequently to excite the bone mischief in the spine, as they certainly do analogous bone disease CARIES. 287 elsewtere, in those wlio are predisposed; possibly, sometimes, in healthy persons. Falls, blows on the back, and severe strains are the most frequent traumatic antecedents. The last may act by straining the ligaments and setting up inflammation, which spreads to the bones directly or through the intervertebral cartilages. There is usually an interval, sometimes of many months, between the injury and the definite symptoms of bone disease. Other causes besides scrofulous disease have occasionally been known to cause breaking down of the bodies of the vertebrse with angular curvature and all its consequences. Soft growths in the spine and, in rare cases, syphilitic formations have had the same effect. Osteitis, due to extension from adjacent inflammation, is a rare cause ; thus caries of the cervical spine has been secondary to a primary retro-pharyngeal abscess. The disease sometimes follows septicaemia, probably in consequence of a secondary septicsemic abscess in the bone. This was the case in a surgeon about sixty years of age, in whom symptoms of blood-poisoning followed an injury to the ankle. They were succeeded by paraplegia of rapid onset, and this by the development of angular curvature in the lower dorsal region. In a large number of cases no exciting cause can be traced. Pathological Anatomt. — The changes in the bones need not detain us, since they belong to surgical pathology, except in so far as they lead to damage to the cord. There is inflammation of the bodies of the vertebrae, and of the intervertebral substance, often at first with enlargement, afterwards with breaking down of the substance of the bone, which gives way under the pressure to which it is exposed, so that deformity of the spine results. Products of inflammation and destruction of tissue, more or less purulent in character, accumulate either inside the canal or outside the vertebral column. In the latter situation they are increased in quantity by the inflammation they excite, and the well-known forms of abscess result. Within the canal the inflammatory products have a firmer con- sistence. Although the inflammation extends to the loose cellular and adipose tissue between the bone and the dura mater, and often to the dura mater itself, it has little tendency to spread as a purulent menin- gitis, or even to penetrate the dura mater, the outer layer of which becomes irregularly thickened in the neighbourhood of the disease (see Fig. 93), while the inner surface of the membrane remains normal. The firm consistence of the inflammatory products, often caseous in character, is an important pathological feature, because this material is so often the agent by which the cord is compressed. The displacement that results from the disease varies according to the extent and character of the, disease. Occasionally there is simply a lateral displacement — one spine is a little to one side of that above it. More commonly the collapse of the bodies leads to "angular curvature," the spinal column is bent forwards at an acute angle, and one or two vertebral spines are much more prominent than the 288 DISEASES OF THE SPINE. others. There is often, however, a less abrupt bend; the curvature may extend over four or five vertebrse. Less commonly one spine projects more than the others without any curvature. The nerves, as they pass through the membranes and intervertebral foramina, are irritated by the inflammation, and often compressed by the thickening of the dura mater which sheaths them, and those passing by the seat of compression may also suffer from the narrow- ing of the canal. They may be foimd red and swollen, or shrunken and grey. They may be damaged when the cord is normal, or but little affected when this is compressed. The damage to the spinal cord depends on the secondary conse- quences of the caries, and is variable and uncertain in both occurrence and character. The mechanism of the damage is twofold — compression and inflammation. The relation between the two is considered more fuUy in a subsequent chapter (Compression of the Spinal Cord). Slow compression may be attended by chronic inflammation, secon- dary not only in character but in course, or by an acute inflammation out of proportion to the com- pression, alike in degree of severity and in rapidity of development. It is important to recognise these differences. The mechanism of compression varies. The most frequent is the collection of inflammatory products outside the dura mater and the thickening of this mem- brane. Less commonly the cord is compressed by the displace- ment of the bone, or by frag- ments of bone that are pushed into the canal. Often both these causes are influential, as in the case shown in Fig. 92, in which the compression (at s) is between displaced bone in front and in- flammatory products (e) behind. Probably an inflammatory swell- ing or abscess of the bone is sometimes the mechanism of compression, since the signs of pressure have disappeared when an abscess has formed outside the spine, or even when defor- mity has come on — the breaking down of the bodies having relieved the compression produced by theii enlargement. Fia. 92. — Caries of the spine, mid-dorsal region. The spinal cord is much nar- rowed and discoloured at s from com- pression between the displaced bone and a mass of inflammatory products, B, outside the dura mater, d m, the inner surface of which ia normal. (After Leyden.) OAEIES. 289 Symptoms. — Caries of tte spine causes symptoms of tliree classes : (1) those of the bone disease ; (2) the effects of damage to the nerve- roots; (3) those dne to the changes in the cord itself. Only the symptoms due to the damage to nerves and cord come within the special province of this book, but the bone symptoms are cf much importance, as on them the diagnosis of the cause of the nervous symptoms often depends. It is this which gives the subject its high medical importance, and brings the symptoms and recognition of bone disease into the province of practical medicine. Symptoms of Bone Disease. — The first is pain in the spine, chiefly felt at the affected spot, increased by movement, and especially by pressure on the bone. The local tenderness is a very important sign. It is elicited both by direct pressure on the spines and by lateral pressure ; if they are grasped and pressed to one side considerable pain is usually produced. Nevertheless tenderness is occasionally absent, not only in cases of slight character and doubtful nature, but also in those in which paraplegia has come on some time after local curi^ature. The increase of pain by movement is greatest when the disease is in the more mobile parts of the vertebral column, especially when it is in the cervical region. Movement of the head occasions pain, and there is an instinctive fixation of the head, which is sometimes inclined to right or left, less commonly backwards. It may thus produce the aspect of torticollis, which differs from that due to muscular contrac- tion in that the sterno-mastoid is tense on the side towards which the head is turned, the muscle being simply stretched by the deviation of the head. The deformity of the spine is a later symptom than the tenderness, and usually comes on gradually. Its characters have been already described. It is often absent when the disease is in the cervical region. In this part there is usually another symptom — ^thickening of the tissues about the spine, which is rare La other parts. In any region an abscess may form in the neighbourhood of the disease. Those which come backwards, or descend to the groin by the psoas muscle, can be recognised externally. Those that form in front of the diseased vertebrae may give rise to symptoms that are puzzling, if the existence of spinal caries is not known. Thus a retro-pharyngeal abscess may cause difficulty of deglutition, and one in the dorsal region may cause symptoms of oesophageal obstruction. Increased pain and tenderness in the vertebral column often precede the indications of damage to its contents. The symptoms due to in- terference with the nerve-roots are very variable, and may be severe or absent ; usually they are moderate in degree, and consist of pain on move- ment along the course and in the distribution of the nerves that emerge at the affected region, often hypersesthesia of corresponding extent, sometimes with spots of anaesthesia. There is also muscular weakness and sometimes muscular wasting. These sjrmptoms are more fully described in the chapter on Compression. Here it may suffice to VOL. I. 19 290 DISEASES OF THE SPINE. say tliat they are conspicuous only in tlie minority of tlie cases, and chiefly occur when there is pachymeningitis. The motor symptoms are most marked when the disease is in the cervical region, and the nerve-roots for the muscles of the arms are damaged, since slight and limited impairment is more readily recognised in the arms than in the trunk. If the disease is in the highest part of this region, the paias may be referred to the occiput. Herpes zoster has been occasionally met with along the course of the irritated nerves. Spasmodic contrac- tion in the muscles supplied by the affected roots is extremely rare in cases of caries. Reflex action is abolished in the affected parts, and the change in the superficial reflexes of the trunk sometimes gives important diagnostic information. Disease of the lower cervical roots may cause symptoms of deranged action of the sympathetic on that side of the head, occasionally shown in the pupil, more often in the vessels. I have seen persistent sweating on one half of the forehead from this cause. The symptoms of interference with the functions of the spinal cord itself are chiefly due to impairment of its conducting power, causing paralysis below the lesion. As the disease is most frequently in some part of the dorsal region, paralysis of the legs is the common effect. But the symptoms vary in their characters, according not only to the position of the disease, but also to the immediate process of damage to the cord. The signs of caries may have existed for years before paralysis comes on. Angular curvature may even come on in early childhood, and paralysis not till adult life More commonly the interval between the two is not long, varying from a few months to one or two years, but either may first be conspicuous. The cases are numerous in which caries is not suspected until the paralysis leads to an examination of the spine, and it is not uncommon for the signs of bone disease to remain equivocal for some time after paraplegia has developed. The cord symptoms vary much in their mode of onset. Usually there is no exciting cause, but sometimes a strain of the back or exposui-e to cold seems to excite a change in the condition of the bones, in consequence of which the cord suffers. It is easy to conceive that, when the conditions are favorable, a very slight strain may be effective, even as slight as the sneezing in the case mentioned below. When the cord symptoms have commenced, they may develop quickly or slowly. As instances of chronic onset may be mentioned cases in which the symptoms reached a considerable degree of intensity at the end of nine months, four months, and two months, after their com- mencement. But the onset is sometimes much more rapid; in one ■case there was complete paraplegia at the end of three weeks. Some- times it is still more acute, and in such cases, when there is no corre- sponding change in the bone, acute myelitis set up by slight pressure is probably the mechanism by which the cord suffers. Thus, in one patient, a child of three, sUght weakness existed for three weeks, anr" CARIES. 291 then the power of standing was lost in a single niglit. In another child, aged eight, who had presented for two yeats indications of disease of the cervical vertebrae, the power of moving the legs was lost in the course of twenty -four hours; during the second day the left arm became paralysed, and, at the end of a week, the right arm. Very rarely the onset is instantaneous, probably from sudden dis- placement. A child with angular curvature was walking across the room, when she fell, and on being lifted up the legs were powerless. The more rapidly compression occurs, the slighter is the amount necessary to abolish conduction. Both legs usually suffer together; rarely one is paralysed before the other ; very rarely one leg suffers much and the other little or not at all. Thus in one case angular curvature developed in childhood ; at sixteen there was an attack of weakness in the legs, which passed away at the end of three weeks. At 17-j the patient sprained his back; pain in it followed, and six weeks later the right leg gradually became weak, and a year afterwards presented intense spastic paralysis, the left leg being very little affected. He idtimately recovered. An instance in which one leg became affected before the other is that of a woman, forty-five years of age, who suffered from pain in the spine, and one day, when walking, sneezed violently three times, and imme- diately felt " pins and needles " about the right knee, and presently in the foot. The leg became almost powerless during the next three days. A fortnight afterwards she felt similar tingling in the left knee, and at the end of another week in the foot, and during the next three weeks this also lost power, so that at the end of six weeks from the onset both legs were motionless. The diagnosis was verified on her death, six months later. The characters of the paralysis in relation to the seat of the disease are described in the chapter on Compression. In the most frequent cases the dorsal cord is damaged, and whenever the compression is above the lumbar enlargement the condition of the legs is that of " spastic paraplegia." If it is situated in the cervical region there may be muscular atrophy in the arms, sometimes palsy without atrophy, according to the seat of the disease. When, as is com- monly the case, the arms suffer from damage to the nerve-roots, they suffer before the legs, but if the disease is so high up that the arms suffer from the damage to the cord, the legs may be paralysed before the arms, as in the case of the child mentioned above. In this case the muscles of the shoulder were wasted, the disease being at the level of their nerves, while the forearm muscles were not wasted. In this case, as in others of similar seat, the diaphragm was paralysed. The muscular part of the spinal accessory may be involved, and the power of supporting the head may be almost lost. Very rarely, from the disease of the highest cervical vertebrae, other nerves of the medulla are implicated, especially the hypoglossal and the fibres of the spinal accessory for the palate. 292 DISEASES OF THE SPINE. Sensory symptoms due to the disease of tlie cord are less com.moii than motor palsy. The onset of paraplegia may be preceded by subjective sensations in the legs. Dull aching pain in them is also not uncommon. Often there is no loss of sensation ; in other cases there are various degrees of loss. Touch or pain may be impaired alone, or there may be absolute loss of sensibility up to the level of the lesion. Partial loss is more common. Keflex action in all forms is excessive (unless the disease involves the lumbar enlargement), and great excess of the superficial reflex action is a common and important feature. The legs are often cold, and sometimes perspire continually. The sphincters are often affected, sometimes early, but they may escape even where there is complete motor palsy of the legs. Complications. — Among common complications are bedsores, cystitis, various secondary effects of the bone disease, such as abscess, local scrofulpus disease elsewhere, and general tuberculosis. Tubercular tumours in the brain occasionally coincide with the caries. In very severe cases peculiar secondary mischief has occurred in the spinal cord, and has run an independent course, giving rise to very anomaloua symptoms.* Thus a descending myelitis may invade the lumbar enlargement in its entirety and abolish its central and reflex func- tions, causing rapid wasting of the muscles and acute trophic changes in the skin. Inflammation may ascend the pyramidal tracts and thus paralyse the arms — an instance of the strange limitation of inflamma- tion to functional tracts when it passes in a direction opposite to secondary degeneration. Ascending degeneration of the posterior median columns may spread to the postero-external columns, and cause symptoms of ataxy by invading root-fibres at a higher level. Ataxy may come on as the power returns, when the disease is in the dorsal region, probably by damage to the path from the muscles to the cerebellum. Lastly, myelitis may occur in disseminated foci in various parts of the cord, and even in the medulla, giving rise to scattered symptoms of anomalous character. Course. — The bone disease may heal, imion occurring between the altered tissues, or it may persist with continued formation of pus, or may become quiescent with occasional periods of renewed activiiy. The cord mischief is influenced by the state of the bone disease, although its progress may be to some extent independent. Thus inflammation in the cord, in excess of the compression, may subside in spite of the continuance of the bone mischief. Pressure on the cord may be relieved, although the bone disease continues, and even some- times as a result of the increased breaking down of bone and exit of pus by another channel. A case is mentioned below in which para- plegia passed away as angular curvature developed. Hence there is no strict correspondence between the course of the bone mischief and that of the cord disease. In some cases the paralysis, motor and sensory, persists. More often the sensory loss passes away, while • See Charcot, •Le9ons sur les Mai. da Syst. Nerv.,' torn. ii. OAEIES. 293 motor paralysis remains, usually as spastic paraplegia, and, in severe cases, flexor spasm comes on with muscular contractions. Life may be prolonged in that condition for years, but often, in such cases, bedsores form, or cystitis leads to kidney disease, or other tubercular disease develops and leads to death, or the lessened respiratory power renders an attack of bronchitis fatal. In many cases, again, the paralysis gradually passes away even when the compression continues, and the cord is found considerably narrowed if the patient dies from some other cause. It is possible that such compression is sometimes produced slowly without impairment of conduction. In children re- covery occurs far more readily than in adults. Even in adults, how- ' ever, recovery may occur from palsy that has la.sted for more than a year, with all the signs of descending degeneration in the cord, amounting to severe spastic paraplegia. Usually rest on the back or mechanical supports are necessary to secure recovery, but it occasionally occurs without these mea.sures. A youth acquired angular curvature at sixteen ; at twenty paraplegia came on slowly, and pro- gressed with some variations during the next seven years. There was then absolute motor palsy in the legs, and sensation was lessened. He refused to rest, and continued to follow his occupation, which was however a restful one, that of a tailor ; he took cod-liver oil and iron, and gradually regained useful power, so as to be able to walk about. Such a case, however, is exceptional. Eelapses sometimes occur in cases that improve, although they are certainly not nearly so frequent as might be expected from the nature , of the disease. In the majority of cases recovery, once obtained, is permanent. In a minority the paralysis returns when some exciting cause renews activity in the bone disease. The tendency to relapse and the possibiUty of repeated recovery are very strikingly shown by the following case. In a girl of fifteen, paraplegia developed during nine months, slowly at first, more rapidly towards the end of that time. She came under my care six months later, having been unable even to move her legs for that time. Bone disease had not been previously suspected, but there was slight tenderness and enough lateral irregu- larity of the lower dorsal spines to show the nature of the case. Rest in bed and tonics were soon followed by imj)rovement ; in six weeks she could stand, and in four months was able to walk well. As she gained powef, angular curvature came on, prominence of the seventh and eighth dorsal spines. Five months after her discharge she fell and struck her back ; the ciu'vature increased, and her legs gradually became weak again. Seven months after the fall she was readmitted, unable to stand, although the paralysis was not absolute. There was foot-clonus on each side. Sensibility was lessened below the ensiform cartilage. Rest on the back was again followed by slow improvement. In three months she could just walk. She was then suspended, and encased in plaster of Paris. At the end of another month she could walk about the room, and no clonus could be obtained. She was soon 294. DISEASES OP THE SPINE. afterwards discharged, and lier progress continued, so that, at the end of nine months, she could walk five miles, and there was no trace of clonus, although there was still some excess of the knee-jerk. She soon afterwards married, and bore a child, which died two years and a half after her discharge. She caught cold at the funeral, and a fort- night later again began to lose power ; in six weeks the legs were almost motionless, with marked foot-clonus ; sensation to touch was lost up to the umbilicus, that of pain being preserved. Neither rest nor encasement caused any improvement. After some months sulphide of calcium was given, and in a few days power began to return ; in a month she could take a few steps, and in four months she could walk about the ward without difficulty. She made another good recovery. Some years later, however, paralysis again came on, and this attack proved permanent. Several cases have come under my notice in which the subjects of caries in early life, which healed without damaging the cord, have at some period in adult life presented the symptoms of primary lateral sclerosis — simple spastic paraplegia, without any root symptoms or evidence of renewed activity of the bone disease. If there is a con- nection between the two, it is probable that the cord has suffered compression so slowly that its functions have not been interfered with, but, nevertheless, the vitality of the pyramidal fibres has been rendered less enduring. It is important to remember that the deviation is often lateral,* and the chief difficulty is due to the fact that a slight lateral deviation or slight prominence is not unusual in normal spines. Hence it is important for the student to make himself familiar with the degrees of deviation that occur in health. At the same time it must not be forgotten that a deviation not greater than occurs in health may be due to disease. If it coincides with distinct tenderness, and especially also with the position of root symptoms, it may be accepted as evidence of disease, probable or certain, according to the character of the symptoms. The pathology of the affection only concerns us so far as it relates to the effect on the spinal cord, and this is considered in the chapter on Compression. Diagnosis. — When clear indications of caries precede the paralysis, the nature of the case can hardly be mistaken. The obvious inference, that the affection of the cord is secondary to that of the bone, is scarcely ever wrong. When the two develop together, mistakes in diagnosis are often made, but are usually due to the want of repeated examinations of the spinal column. It is when the root or cord symptoms precede distinct evidence of bone disease, and when the latter is so slight as to be equivocal, that the chief real difficulty in * To discover lateral deviation it is well to make an ink-dot on the skin over the middle of the tip of each spine, care being taken that the skin ia not stretched to one side. The ink-dots may be copied on tracing-paper. CAETBS. 295 diagnosis occurs; the affection is apt to be mistaken for a primary disease of the oord or its membranes — a transverse myelitis when the dorsal region is affected, a progressive muscular atrophy, or primary pachymeningitis, when the disease is in the cervical region. A correct diagnosis can only be made in these cases by recognising the signifi- cance of the slight bone symptoms that are always present, the deep tenderness, and often slight irregularity. Even slight irregularity derives significance from tenderness, limited in extent and correspond- ing in position to the deviation. The irregularity may be a,bsent at first, and then its development is doubly significant. An observed increase in the amoujat of displacement gives significance to even a slight irregularity. The early excess of the cutaneous reflex action (from the sole, for instance) , while not conclusive, adds weight to the other symptoms of bone disease. It may be very marked even while the patient is able to walk about. Distinct root pains are always of great significance, and this is increased by tlie detection of spots of anaesthesia along their course. All these symptoms derive additional weight from their coincidence in level with the spinal irregularity. It is this which enables the pains to be distinguished from the con- dition for which they are most frequently mistaken — a trunk neuralgia. This error is especially common when the pain is chiefly unilateral. In all such cases the spine should be carefully examined, and any tender- ness of the bone at the level of the pain should excite suspicion. I have also known unilateral abdominal pain due to caries to be mis- taken for that of renal calculus. When damage to the cervical roots causes muscular wasting in the arms, the case may be mistaken for one of progressive muscular atrophy, but differs m the distribution of the wasting, in the pains, and the impan-ment of sensation. These occur in primary cervical pachymeningitis, which is distinguished by the absence of the signs of bone disease, and. in the wider extent through which the root symptoms extend. In the first half of life the recognition of bone disease is practically tantamount to the recognition of caries. In the second half, however, the relative infrequency of caries, the greater frequency of growths in the bone, and the occurrence of eroding aneurisms, introduce a fresh diagnostic problem. The absence of any other indication of a tumour or an aneurism is the first distinction ; and the second is the fact that in both these diseases the root pains commonly reach a degree of severity scarcely ever attained in caries, a ad are especially increased by movement. When there are merely tenderness of the spine and slight weakness of the legs, the question may arise whether there is organic disease, or merely the condition termed " spinal irritation," or mere functional pain and tenderness and weakness of the legs. In these cases the tenderness is usually found, over a considerable area of the spinal 296 DISEASES OF THE SPINE. column, witli more than one point of special intensity ; it is superficial as well as deep, and may change its seat ; there are no root pains or spots of anaesthesia. There is more danger that caries of the spine in a young woman may be passed as hysterical paraplegia than of the opposite error. Especially when the subjects of caries present distinct symptoms of hysteria, there is risk, as experience shows, that un- equivocal symptoms of caries may be overlooked. Some other diagnostic indications are mentioned in the chapter on Compres- sion. Peognosis. — Our ignorance of the precise character of the morbid process which is damagiag the cord renders the prognosis, ia every case of caries, a matter of much uncertainty. Nevertheless there is no disease of the cord in which symptoms of equal gravity so often pass away. The cases are few, therefore, in which hope is unjustified, but they are equally few in which we are warranted in a confident expectation of recovery. In childhood the prospects of recovery are certainly better than in adidt life, and they are least in declining years. Damage to the cord between the enlargements is less serious than when these are affected, because the strong tendency to trophic changes constitutes a grave danger when the lumbar enlargement ia diseased, and the diminished breathing power an equally serious danger in disease of the cerAdcal enlargement, especially when this is high enough to entail the additional danger of paralysis of the diaphragm. But how perilous a condition may be recovered from is shown by the fact that the child mentioned on p. 291 had paralysis of all four limbs, the diaphragm, and weakening of the intercostals, and yet recovered. Still more striking is a case narrated by Dr. Buzzard, in which disease in the region of the third cervical vertebra caused almost complete palsy of arms, legs, intercostals, and diaphragm, respiration being carried on by the accessory muscles of the neck» Yet the child recovered in spite of the occurrence of an attack of pneumonia when the paralysis was at its height. A girl of thirteen, whose cervical caries was accompanied by all the symj)toms of cere- bellar tubercle, recovered. All these, it will be noted, were children. Neither rapidity nor slowness of onset affords any guide to prognosis, nor does the relative order of paralysis and curvature, or the degree of palsy. Severe spastic paraplegia may pass away entirely, provided it remains extensor in character. The prognosis is perhaps a little better when there is no loss of sensation, since this proves that the damage to the cord is moderate in degree ; but even complete anaes- thesia does not preclude recovery, as the cases mentioned show. The danger to life is dependent in considerable degree on the evidence that the scrofulous or tubercular tendency is active elsewhere, and also on any difficiilty in securing proper treatment. The prognosis is, more- over, still in a transitional state on account of the uncertainty regard- inof the range of successful surgical treatment. CARIES. 297 Treatment. — The first and cHef element in tlie treatment of paralysis is tliat of tlie bone disease wliicli causes it, and for fuU •details of this the reader is referred to treatises on surgery. It includes both the older means of securing an arrest of the morbid process, and the still recent measures of operative treatment. If the bone disease heals, the spinal cord, in most cases, will recover. The two most potent therapeutic agents are persistent recumbency and tonics, especially cod-liver oil and iron. In the cases that have done best, these, and these alone, have been the effective agents. Eest should be maintained for months. The posture that answers best is upon the back, on account of the greater ease with which immobility of the bone is secured and maintained, and the great importance of this element in treatment; this position is also the most comfortable, and local pain probably interferes with the sub- sidence of local inflammation. If no improvement occurs after some months' rest, suspension may be tried. It is said to be sometimes attended by instant improvement, especially in children; but this result is rare, and can only occur in the cases, not very common, in which displaced bone compresses the cord. In cases in which there is reason to suspect that this is the cause of paralysis, it may be well to see the effect of suspension before rest is commenced. The moulded jacket is an inefficient substitute for rest, and an unnecessary con- <;omitant — to be adopted only when rest cannot be secured, or after rest alone has apparently done all that it can achieve. If, for instance, power gradually returns diu-ing rest, but the improvement after a time ceases, and the bone disease seems inactive, the patient may be sus- pended, encased, and then permitted to stand and walk ; improvement may be renewed and power may rapidly increase. In caries of the mobile cervical spine, even during the period of rest, fixation of the head is necessary. Extension of the spine in the recumbent posture has also been employed, sometimes with apparent benefit. The head of the patient is fastened to the head of the bed by an elastic band attached to a strap passing beneath the occipital protuberance and round the patient's head. A weight of from 4 to 12, or even 20 lbs., is fastened to a band passing round the patient above the hips. Con- tinuous extension is thus obtained.* More recently sudden forcible extension of the spine and immediate reduction of the deformity has been recommended as a mode of treatment for spinal caries. In some cases in which paraplegia was present, rapid return of power in the ])aralysed limbs has occurred after this treatment ; but it is obvious that such a method has inherent in it certain dangers which are at least minimised in less heroic treatment.f The influence of cod-hver oil and iron is as marked in this as in other scrofulous diseases. They constitute an indispensable adjunct * Flemin<^^^„.,.|^ ^,j^- ,« r (Fig. 100). The processes '^^ extend between the nerve- fibres. "We have seen that their existence in the normal ^jy ^^ ^ -^ ^ cord has been doubted, but in ^&\^ '^%^*''^ - the inflamed cord, in which ^0^^^^'^#^^'y-^\?-,y\"TL' ^ they are enlarged, their pre- ^'^^h'^^'Q>^'^^^''^'i-^ "■ -1^.1^^-^ ^„ •^ sence IS distinct. <^-^'.i ^ •>4»>»" The changes in the nerve- „, I mi, ViQ. 100. — Subacute disseminated myelitis; fibres vary much. Ihey pan. of the posterior columu. Nerve-fibres always suffer destructive separated by granular material and products changes, but the products of of degeneration and by numerous large ° ' ,^ spider cells. Ine myelitis in this case was their degeneration, above attended by optic neuritis. (From a see- described, are scarcely to be tion lent by Dr. Dreschfeld.) seen in cleared specimens. The slightest change in the myelin appears to consist in an alteration in its chemical nature, in consequence of which it stains more readily than in health. Fibres are thus changed adjacent to any increase in the interstitial tissue, and they contrast with the unstained healthy fibres in the vicinity (Fig. 101, c). With or without this change in the myelin, there is an irregular swelling of the axis-cylinders, such as is seen on examination in the fresh state. If the fibres are divided * The significance of this vacuolation has been much discussed. It is probable that the vacuoles form after death, perhaps during the process of hardening, but that they do not form unless the cells have been altered by disease. They have thus some pathological significance. 852 SPINAL COED. transversely at the places wliere the axis-cylinder is swollen, this appears much larger than normal (Fig. 97, 6). Examples of this will be found in most of the figures. These intense degenerative changes cause the breaking up of the myelin, and may involve the destruction of the fibre, the space occupied by it being left empty. In othe] cases, however, the axis-cylinder persists and remains sur- Flff. 101. — Acute transverse myelitis, fatal in three weel,l11 be the ultimate recovery. If some power returns within a fortnight, the amount that will be regained ■will probably be great ; but even complete loss of power for six months does not preclude the ultimate return of the ability to walk, and I have even known this result after complete paralysis for a year from transverse myelitis. The development of increased myotatic irrita- bility shows that improvement wiU not speedily occur, but even rigidity and the state of " spastic paraplegia " does not lessen materi- ally the prospect of some recovery in a case in which the loss of power remains complete for a month or more. Indeed, the spasm often enables the patient to stand with a slighter degree of volimtary power than would suffice if the limbs were supple. The fact of preceding syphilis must be allowed very little influence on the prognosis ia a case of simple acute myelitis, but greatly im- proves the prognosis i£ there are indications that the inflammation is secondary to a more chronic process outside the cord. Treatment. — If a case comes tinder observation at the earliest period, when only slight sensory disturbance and slight weakness of the legs indicate the commencing process, the question arises whether 874 SPINAL COED. any treatment can avert the further development of the inflammation. If the symptoms are clearly due to exposure to cold, a hot bath, followed by free diaphoresis, should be employed, and followed by counter-irritation and the other measures now described. If con- siderable paralysis shows that the process of inflammation is fulJy developed, little can be expected from these measures, and it is better not to subject the patient to treatment that is incompatible with perfect rest. This, in all cases, is of paramount importance. Both functional excitation of the cord and movement of the spinal column should be avoided. The remarks regarding posture made in the account of the treatment of inflammation of the membranes apply also o that of the cord itself ; it is most undesirable that the spine should be the lowest part of the body, and it is rather less diffictdt to keep the patient off the back in myelitis than in menin- gitis. A. plank back-rest in the bed will be found a great assistance in securing comfortable rest on the side. If there is any reason to suspect haemorrhage, or if there are indications of rapid extension of the inflammation, the prone position should be adopted, and even in myelitis it is well to adopt it at times as a change from the lateral posture. The removal of blood from the skin of the back over the affected region, by leeches or wet cupping, is an old measure, which finds some theoretical justification in the fact that the blood from the structures behind the spine passes into the same veins as the blood from the spinal cord itself. Hence this measure may conceivably have some influence on the circulation in the cord. If the patient's strength is not such as to render the abstraction of blood desirable, dry cupping may be employed, or the vessels of the skin may be dilated by hot fomentations, or a mustard plaster, or hot water bags. By stimu- lating the < utaneous nerves, these agents may also influence, in a reflex manner, the vessels of the cord. The application of cold to the spine, as by a spinal ice-bag, has also been recommended. Conti-ciry as these therapeutic agents seem, it is probable that each moderates local inflammation in the same manner, by causing first contraction and then dilatation of the vessels of the inflamed part, and so lessening the tendency to stasis of the blood, on which some effects of inflammation depend. Unless there is reason to suspect haemorrhage, the applica- tion of warmth is the safer and probably, judging from experience, the more effectual. At the very onset of inflammation mild counter- irritation is unquestionably useful, and even a blister may be em- ployed. The actual cautery of Paquelin, applied in a series of spots along each side of the spine, is probably more effective, and less liable to set up or intensify trophic disturbance ; but when the process has reached a considerable degree it is very doubtful whether counter- irritation has much influence until the acute stage is over. In other respects the treatment of acute inflammation of the cord must be guided rather by the nature of the process than by the ACUTE MYELITIS. 875 chaiacter of the organ in whicTi it occurs, and the fact that it is an acute local inflammation should be kept in view. A nutritious hut unstimulating diet, aperients, and diuretics are desirable in all cases. If there is constipation a free purgative may be given. Whenever there is evidence of a morbid blood-state, it is important that this should, if possible, be improved, but we have still to learn how most toxsemic states can be neutralised. ISTitrous ether may be given as a diuretic with some tincture of digitalis, which tends to render the circulation uniform, and to lessen stasis by its influence on the small arteries. The reason for diuresis is that probably no local inflamma- tion occurs that is not associated with a morbid state of the blood, which may be to some extent relieved by the action of the kidneys. If any special drug is given, it may be combined with those above named. It is as difficult to ascertain the effect of the drugs which are supposed to exert a special influence on myelitis, as it is in the case of other local inflammations, which have no predetermined degree, and tend to subside when they have reached their height. Ergot was recommended by Brown- Sequard, chiefly on theoretical, grounds, and has been extensively employed. In rare cases it has seemed to do good. In cases of haemorrhagic myelitis it may reason- ably be given with greater confidence, or ergotin (3 to 5 grs.) may be injected beneath the skin. Belladonna has also been recommended, but the evidence that it influences the morbid process is not strong. Mercury has been largely employed, given by the mouth and by inunction. The influence of mercury on the inflammation of internal organs does not seem so great as upon that of the fibrous tissues and of the structures that invest organs. Certainly in myelitis its effect is less distinct than it is in many cases of meningitis. Iodide of potassium seems to be no more efficacious than mercury. In eases of transverse myelitis occurring in syphilitic subjects the treatment for syphilis seems to have but little influence on the morbid process. It is true that such treatment is rarely adopted at the very onset of acute myelitis, but after the disease has developed energetic treatment does not seem to modify its subsequent course. This is true also of the subacute disseminated myelitis that occurs in the subjects of syphiHs, and might be expected to be more amenable. I have known this form, concurring with syphilitic disease of the cerebral arteries, to develop and run its course to a fatal termination in spite of con- tinuous antisyphiHtic treatment, to which the arteritis yielded. In the general management of a case of myelitis, two points are of extreme importance. One is to avoid, by scrupulous cleanliness and care, the exciting causes of bedsores. The skin should be most care- fully watched, and any indication of deleterious pressure met by a change of position or an alteration of the mode of supporting the part. Cotton wool is very useful for this purpose. If there is a marked tendency to trophic changes the j)atient should be placed on a water- bed. When there is incontiaence of urine, the difficulty of avoiding 376 SPINAL CORD. irritation of tlie skin is greatly increased. For males, a bed urinal is sometimes useful, but often it causes irritation and even sloughing of tbe prepuce, and tben does more harm than good, A quantity of boracic or salicylic absorbent cotton wool, changed as often as it becomes saturated, is one of the best means of meeting this difficulty. It must be remembered that the prevention of bedsores is the pre- vention of one common cause of death. Should offensive sores form, a quantity of picked oakum, placed outside the immediate dressing, is a cheap and most effective means of preserving the air of the room from the foetor of the sores, and is also a useful substitute for absor- bent cotton wool, in the case of the poor, to absorb the urine or receive faeces that are passed unconsciously. Such material is also useful for relieving pressure when a water-bed cannot be obtained. The second point in management is the treatment of retention of urine. If there is either simple retention or overflow incontinence the bladder must be regularly emptied by the catheter, great care being exercised to prevent the introduction of contaminating germs. The importance of daily examining the abdomen to see that retention has not occurred, cannot be exaggerated. If the bladder is left full and the urine allowed to dribble away, inflammation is sure to be set up, and probably also pyelo-nephritis. If cystitis occurs, antiseptic washes must be used to lessen, as far as possible, the decomposition of the urine. Under this influence the cystitis usually lessens, and one grave danger to life is obviated. When the disease of the cord has become stationary, the patient may be allowed to move, and a more tonic treatment may be adopted. Iron, quinine, or arsenic may be given. Strychnia must be given only in very small doses if there is any excess of reflex action. Occasional counter-irritatiop may be employed, repeated frequently if any im- provement seems to result. The limbs may be rubbed, and any muscular wasting treated with electricity. It is not desirable to use electricity as a therapeutic agent while the cord disease is in an acutely active stage. There is no evidence that the application of electricity to the spinal column has any influence on the process of recovery of the cord. Its chief value is to maintain, as far as possible, the nutrition of any muscles of which the nerves have undergone de- ge'neration. In cases of dorsal myelitis, in which the legs are well nourished, and the reflex action is excessive, it is better not to apply any form of electricity. The unavoidable stimulation of the sensory nerves tends to increase the reflex over-action. Careful atten- tion should, in all cases, be paid to the position of the limbs during the stage of helplessness, so as to avoid as far as possible the develop- ment of contractions. Tor the condition of active spasm, which often develops after severe myelitis, not much can be done; such special treatment as can be adopted is described in the chapters on Primary Spastic Paraplegia. ABSCESS OF THE COED. 877 Abscess of the Spinal Coed. Simple inflammation of tlie spinal cord scarcely ever goes on to the formation of pus, although leucocytes may accum-" .e at certain points of the grey matter so densely as to constitute microscopic collections of pus, and in very rare cases of this kind such minute abscesses have been sufficiently large to be visible to the naked eye. Pus only forms in the substance of the cord in considerable quantity in cases of purulent meningitis. In most instances the purulent meningitis has been of septic origin, rarely traumatic. In the former case suppuration within the brain may coincide with that in the Bpinal cord, and in the latter it may be very extensive, and occur at more than one spot. The symptoms are those of an acute irritative myehtis, but they are often lost in those of the purulent meningitis which precedes the disease of the cord itself. Their special feature is their association with a cause of septic suppuration, as well as with a high temperature and other symptoms of a septic blood-state. A good example of the disease is a case recorded by Nothnagel. A patient suffering from cough and most offensive expectoration was suddenly seized with severe pains on both sides of the abdomen, attended by a sense of constriction and quickly followed by paralysis of the bladder and of the legs, with loss of sensation and of reflex action. An abscess of the cord was diagnosed. After death there was extensive purulent spinal meningitis, and the dorsal and lumbar cord contained an extensive collection of gangrenous offensive pus, which seemed to occupy the central part of the cord, from the cervical enlargement downwards. Some abscesses were found also in the white substance of the brain. In another case described by Ullman* two extensive foci of suppuration existed in the cord, one cervical, the other lumbar ; the former had caused extensive destruction of tissue, and the pus had escaped into the subdural space. The affection was supposed to be secondary to gonorrhoea. Embolism op the Spinal Coed. Tlie occurrence of embolism in the spinal cord has not yet been proved, but a few cas^s have been met with which suggest the possibility that the process has been the exciting cause of an acute myelitis. In a young man with mitral regiirgitation, considerable weakness of the right leg came on suddenly — in a moment — with transient spasm. The onset indicated a sudden lesion in ■ the cord, which might well have been the embolic obstruction of a small vessel. In a case recorded by Weiss, a boy aged sixteen, with chronic mitral disease, was suddenly seized with complete paraplegia, followed by * ' Zeitschr. f . kl. Med.,' xvi, 1889. 378 SPINAL CORD. bedsores, &c. He died four montlis after the onset, and the lumbar enlargement was found completely softened, with, old coagula in the arteries. There was embolism of the kidneys and spleen, and the cortex of each cerebral hemisphere presented small foci of softening. Such cases justify a suspicion that embolism may be the cause of a sudden lesion of the cord in a patient in whom a source of embolism exists, and the process has occurred in other organs. Cheonic Myelitis. The spinal cord may be the seat of chronic inflammation, wliicli develops slowly, as such, in the course of a few or many months ; and the condition may also occur as the sequel to acute myelitis, which, instead of subsiding, may persist, manifesting from time to time signs of activity. It is often difficult to sa^y whether such a condition should be regarded as an acute myelitis that has not subsided, or a chronic inflammation beginning acutely. In many instances, indeed, it is probable that the disease is most accurately regarded as a combined form in which the causes of both are operative, and a subsiding acute inflammation is arrested and maintained by the influences that would be capable of inducing a primary chronic myelitis. Such progressive tendency is especially conspicuous in the disseminated form, in which the foci of inflammation may remain, and fresh ones may develop from time to time in. a chronic or subacute manner. The lesions of chronic myelitis resemble those of acute myelitis in seat and distribution, and intermediate cases connect them by analogous subacute forms. They differ from acute inflammation both in the longer time occupied in their development, and in the absence of the considerable vascular disturbance which forms part of the acute process. Such chronic myelitis may be focal, disseminated, or diffuse. In the former case it may involve the whole thickness of the cord at a certain level — chronic transverse myelitis ; or only part of it, sometimes one half, occasionally for a considerable vertical extent. The chronic disseminated myelitis may resemble the corresponding subacute form in distribution, many points of inflammation being scattered through a small region, or through a large part of the cord, and its symptoms may become diffuse by the union of the effects of the disease. The term " chronic myelitis " has, however, been used in a much wider sense, and has even been applied by some to all local processes attended by an increase of interstitial tissue, whether this is primary or is merely secondary to a degeneration of the nerve-elements. Thus the degeneration of the nerve-cells in progressive muscular atrophy has been regarded and described by many as a chronic myelitis of the grey substance, notwithstanding the fact that there is usually a degeneration of the whole motor path, in both segments, from the CHRONIC MYELITIS. 379 cortex of tlie brain, ttrotigh. the pyramidal tracts and motor nerves, and that the anterior cornua merely constitute, as it were, a focus in which the effects of the processes are especially conspicuous. Such a morbid process is evidently quite different in nature from a focus of ordinary inflammation, in which the primary change is interstitial and random in range and effects, and presents no limitation to func- tion in the incidence of the consequences on the nerve-structures. Whenever this latter feature can be traced, the malady must be regarded as a " system disease," i. e. as a disease affecting a system of nerve- structures that have a common function. If " system diseases " are forms of inflammation, they are " parenchymatous inflammations ; " and those that are chronic in course from beginning to end are more commonly termed " degenerations," and are so classed and described in these pages. Only, then, the chronic interstitial processes of random position and influence are here considered. Etiology. — The causal relations of chronic myelitis, even as thus limited in conception, are very various. An inherited neuropathic tendency can sometimes be traced, but far more rarely than if the cases are included in which the nerve-elements suffer primarily. The disease is most common in early and middle adult life, but it occurs occasionally in old age ; it is met with in both sexes, and is perhaps more prevalent in females in the first half of middle life and in males in the second — an important fact, because so many of the cases in young adult women are thought to be hysterical in nature. Various conditions which lessen constitutional strength predispose to the disease. Definite causes often cannot be traced, although many of the exciting causes of acute myelitis seem capable of giving rise to the chronic form, when acting for a considerable time, or frequently repeated, or in specially predisposed persons. Thus while a single intense exposure to cold may produce acute myelitis, frequent habitual exposure may cause the chronic form. Injury is a frequent cause, and seems to act in more than one way. Chronic inflammation may develop in the vicinity of a damaged spot, when the traumatic lesion may have been too slight to cause pronounced symptoms, or may have caused slight effects which are subsequently lost in the more severe and extensive consequences of the myelitis. In other cases the effects of the lesion may be too slight in degree to be at first perceptible, but (either by a slow influence on the processes of nutrition, or by extensive minute interstitial lesions that induce secondary traumatic inflammation) the symptoms of extensive damage to the cord slowly follow an injury that has no immediate effect on function. These cases will be further considered in a subsequent chapter. Repeated over-exertion has also seemed effective in some cases. Sexual excess has been thought to be a cause, but on less clear evidence. Chronic myeUtis may be secondary to other local morbid processes, especially to adjacent inflammation, which, when it also causes coxa- 380 SPINAL COED. pression, invariaWy gives rise to clironic myelitis ; the inflammation that results from pressure on the cord may be either chronic or acute. Another series of causes consists of constitutional states capable of giving rise to local inflammations. Chronic alcoholism is, perhaps, the most influential and important of these. Chronic myelitis due to it is usually associated with chronic meningitis, and most intense at the periphery, beneath the inflamed membranes; but it thence extends into the substance of the cord, and sometimes tracts of irregular extent and position are involved, without connection with the membranes. This cause is one of especial importance, because it often co-operates with others, and determines effects that may seem to be independent. Its effect is met with, for example, in many cases of chronic myelitis that are excited by injury and seem to be due solely to the excitant, although the results of this would have been trifling and transient but for the tendency induced by the preceding and often profoimd effect of chronic alcoholism on the tissues. It also complicates many cases of multiple neuritis due to the same cause, in which the effects of the peripheral lesion obscure to a large extent those of the central mischief, by causing symptoms that pre- vent the recognition of the latter, since its consequences are lost, as it were, in those of the damage to the nerves. The gouty diathesis is another cause of chronic myelitis. We are only beginning to realise how often it acts on many organs and tissues, and how frequently inflammation is thus induced. It is certain that this is a common cause of inflammation in the substance of organs and in mucous membranes, and chronic as well as acute myelitis is among its effects. Many cases are due to this influence, and it is instructive to note that, like chronic alcohoHsm, it is also a cause of inflammation of the peripheral nerves. The disseminated and progressive forms of chronic myehtis are especially due to it, and the analogy should be noted which these present to the irregular forms of perineuritis, of which this state is also a common cause. It is probable that many cases of chronic myelitis in young adults, at present mysterious in origin, and in the obstinately progressive character they sometimes manifest, will be found to be due to the influence of inherited gout, which is certainly capable of causing analogous inflammation elsewhere in the nervous system, — as, for instance, in the optic nerves. Another cause of chronic myelitis is constitutional syphilis. The forms that are apparently due to this are of two types. (1) A diffuse interstitial inflammation, most intense at the periphery, with much new formation of tissue and thickening of the walls of the vessels, both processes extending into the cord from the pi a mater, in which a similar damage exists. This form may be subchronic in course, and presents some histological correspondence to known syphilitic pro- cesses. (2) A focal very chronic indurating myelitis, such as shown in Fig. 106, which has no distinctively syphilitic feature, may occur in OHEONIO MYELITIS. 381 very late stages of the constitutional disease. In neither form does the influence of treatment afford evidence of the relation to syphilis. In the second, sclerotic variety it does not appear that treatment has any power to modify the morbid process, and in the first it is evident that any cicatricial process that could be induced would only maintain the damage to the nerve-elements, which would suffer further from the maintained or renewed compression under the prolonged contraction of the enclosing: tissue. Yet the occurrence of these forms in the Fia. 106. Fi&. 107. Fia. 106. — Chronic myelitis. (After Charcot and Gombanlt.) B, section at the level of the tliird dorsal, shows hoth the posterior columns and whole of left half inflamed, except the inner part of the anterior column. The affected part was grey and uniform in aspect, vascular, and firmer than normal. . Pia mater and arachnoid thickened. A, section from cervical enlargement, showing secondary degeneration in the post.-med. columns. Similar foci existed in the pons, &c.* FiO. 107. — Chronic sclerotic myelitis. (After Troisier.) A, posterior view of the affected part, lower dorsal region. The diseased areas were grey in aspect, and are indicated by shading. B, middle of lesion, showing exten- sive damage ; C, 2| cm. higher up, slighter damage ; D, cervical region ascending degeneration, post.-med. cols., and a spot of disease in lateral column (probably part of the ascending ant.-lat. tract, secondarily dege« nerated). E, lower part of lesion. (See next figure.)t * The patient had had syphilis twenty-one years before. The spinal symptomt slowly developed during fifteen months, and consisted in paralysis with hyper- sesthesia on the left side, with loss of sensibility without paralysis in the right, and a band of anaesthesia to pain around the thorax at the level of the lesion, but the mental dnlness of the patient prevented accurate observation during the last few months of her life. (Charcot and Gombanlt, 'Arch, de Phys.,' 1873, vol. vi, p. 143.) t The patient was a woman forty years of age. The symptoms slowly developed during the three years before death, and consisted of weakness with rigidity in the left leg, and impairment of sensibility in the right, first of the temperature sense and afterwards of touch. (No observations were made on sensibility for the last fifteen months of the patient's life, during which the lesion was slowly progressing.) (Troisier. * Arch, de Physiologic,* 1873, vol. y, p. 716, Case 2.) 882 SPINAL COED. subjects of syi^liilis, tlie absence of otber causes, and tbe circamstances that the negative facts are not without analogies, make this causation on the whole the probable one. PATHOLoaicAii Anatomy. — The morbid appearances vary much in the different forms. In most cases the disease is revealed to the naked eye by a change in the aspect of the affected part, in which the white substance is grey in tint, and the grey matter darker than normal, while both are reduced in size in cases of long duration, so that the whole cord may be lessened at the affected part, and its shape changed when the disease does not involve its entire thickness. But in recent cases the alteration in tint may be the most conspicuous change, and may be visible on the surface, even through the pia mater ; this may be thickened at the spot if the disease reaches the surface. The consistence of the affected area may be lessened or increased. Rarely, in recent cases, there is a slight increase in the size of the affected part. In some recorded cases in which a great increase in size has been described, it is probable that an infiltrating glioma was mistaken for chronic inflammation. When there is one considerable focus of disease there may be other slighter foci in the neighbourhood. In what is called the " diffuse " form the diseased areas are scattered through a considerable extent of the cord ; they may blend into a lesion that is truly diffuse, or may remain, in point of fact, disseminated, but be so placed that their effects blend in what may be termed a diffuse influence. Thus it may be found, post mortem, that there are numerous foci of disease when nothing in the character of the symptoms prepared us for a disseminated lesion. It is probable, indeed, that this is the rule in the chronic form, and an actually diffuse extensive inflammation is much more rare than is suggested by the symptoms of the disease. In the secondary form the inflammation is usually confined to the neighbourhood of the morbid process which causes it. That which is secondary to menin- gitis is most intense in the peripheral part of the cord, but sometimes extends deeply, especially when the cause of the meningitis is one, such as alcoholism, capable also of giving rise to myelitis. In this condition almost the whole thickness of the cord may be involved (of. A and B, Fig. 109). Now and then, when there is no primary menin- gitis, the superficial layers of the cord are chiefly damaged, a form that has been termed chronic annular myelitis or annular sclerosis, because the affection extends like a ring around the cord. This form of lesion is, however, as we have seen, sometimes merely an ascending degene- ration of fibres that lie near the surface, and degenerate above the primary lesion. In chronic myelitis, according to the limited use of the term already explained, the microscope shows that the inflammation is primarily interstitial. The affected areas always stain deeply with carmine in consequence of the great increase in their connective-tissue elements, and may be occupied by a dense fibrous reticulum, in which CHBONIO MYELITIS. 383 few nerve-elements can be discovered, as in Fig. 108. In less affected parts of the wMte columns there is an irregular increase of the interstitial tissue, partly fibrillated, partly amorphous, or studded with nuclei (Fig. 108, upper small figure) ; while in other parts it may contain many nucleated cells, oval, fusiform, or stellate. The large stellate " spider cells " are sometimes very conspicuous, and interstitial fibrous tracts may be traced to their ramifications. r^rr^ Fig. 108.— Chronic sclerotic myelitis, same case as Fig. 107; section near B, reversed. Almost the whole left lialf of the cord (right in the figure) is changed into a dense mass of shrunken connective tissue, and the right half is being invaded in many parts by the same process. The upper small figure is from the posterior column, showing a thickened vessel surrounded by nucleated tissue, among which lie nerve- fibres, many of them much smaller than normal, and some with swollen axis-c.\lindcrs. The lower small figure is fi-om the right anterior column (left in figure); the pia mater is thickened and contains many nuclear elemems j from it thick trabeculae extend into the white substance and enclose spaces, from many of which the nerve-fibres have perished.* The nerve-fibres waste before the interstitial process, or undergo destructive changes from the beginning. They may at first present the change by which their myelin stains more deeply than normal ; afterwards they become narrowed, and the axis-cyhnder is often irregularly enlarged. Ultimately many or all the fibres disappear from the affected area. Here and there the destruction of fibres may be out of proportion to the increase in the interstitial tissue, so that thickened and often granular trabeculse enclose empty spaces. This is seen in the lower small illustration in Fig. 108 ; it is apparently the residt of the participation of the nerve-fibres in the inflammatory process during a more general stage, in which all the elements of the tissue were involved. In the recent state, products of degeneration, granule corpuscles, &c., may be found abundantly in the altered * From a section by Prof. Pierrot, kindly lent me by Dr. Dreschfeld. 384 SPINAL CORD. regions. The -walls of tlie vessels are thickened, and by this thickening the cavities of the arteries may be ultimately lessened; those of smaller size may even he closed. Not only is the wall of the arteries thickened, but around them the increase of inter- stitial tissue is often greater than elsewhere, so that the appearance is as if it had spread thence into the adjacent structures. Undue signi- ficance has been attached to this condition, especially in old patients ■with arterial degeneration; it has been regarded as evidence that arterial disease sets up the myelitis, but it is a common appearance in all forms of chronic myelitis, and also in the later stages of acute inflammation. It is probably due to the greater activity of the process in the immediate vicinity of the vessels, and to the share taken by escaped leucocytes in the formation of new interstitial tissue. The peripheral arteries, moreover, occupy tracts of neuroglial and fibrous tissue proceeding from the pia mater, and the increase of interstitial tissue is connected with these ; some of it is, on this account, found in the vicinity of the arteries. In the grey substance there is a similar increase of connective- tissue elements, so that the altered part takes a deeper stain with carmine than the normal grey substance, and has a denser structure, from the greater amount of supporting tissue. The nerve-elements become atrophied ; the ganglion-cells, at first swollen and rounder, afterwards shrink, until ultimately they may be reduced to small angular bodies, and they even may disappear. The nuclear corpuscles about the central canal are often increased in quantity, and the canal obliterated, but this condition is so common in otherwise normal cords that no importance can be attached to it. A considerable increase of tissue about the central canal, closing it below and causing it to be dilated above (Fig. 109, " syringomyelia "), has been ascribed to chronic inflammation around the canal, but the abnormal tissue is probably always of gliomatous nature, consisting of a development of tissue that is in congenital excess, owing to an arrest of develop- ment. The pia mater is greatly thickened over the inflamed parts, as already stated, and in some cases the affection of the membrane is general, and that of the cord most intense beneath it— a condition termed " chronic meningo-myelitis." It is this form that is shown in Fig. 109. The tracts of new tissue that pass into the cord are dense and wide. As already mentioned, this change may be accompanied by a deeper and sometimes a more diffuse inflammation, as in a. Fig. 109, in which the affection of the cord is greater and that of the mem- branes less than ia b. The chronic myelitis that occurs in syphilitic subjects may present no specific characters. In some cases, however, the cell-formation has been abundant, and has been associated with a tendency to fatty degeneration in the older portions of the lesion, and with a similar degenerating hyperplastic inflammation of the pia mater. The condition is, however, clearly one of chronic inflamma- CHUONIO MYELITIS. 885 tion, and not of a sjpliilitic growth.* Nevertheless an actual growth does sometimes co-exist with a focus of syphilitic myelitis ; it is pro- Flff. 109.— Chronic menirgo-iryelitis, due to alcoholism. Syring'O-myelia, CongenitHl, with central gliomatosis. A, lowest part of cervic;il enlai^e- ment; pia mater thickened, and from it tracts of tissue extend into the cord. The greater part of the section is the seat of a diffuse myelitis, in which the nerve-fibies could be seen with d ifficulty, and were sepa« rated by inflammatory products. The grey matter was also affected, and the nerve-cells much changed. The clear spaces in the right ant. coma appeared occupied by products of degeneration. Central canal greatly dilated and surrounded by new growth, which in B (lumbar sec- tion) has obliterated the canal and thus cau-ed its dilatation above. In this section the myelitis is chiefly peripheral, and the grey matter has, for the most part, escaped. bable that in such cases the growth is usually the primary change. This may be distinguished by the indications of compression and displacement of the adjacent elements of the cord, a condition which shows that there is an actual new formation. The more recent the inflammation, the larger is the proportion of cells and nuclei in the interstitial tissue; the longer it has existed, * See Moxon, ' Guy's Hosp. Reports,' 1871, and Charcot and Gombault, * Arch» de Physiologie,' 1873. VOL. I. 25 886 SPINAL CORD. the greater is tlie amount of fibrillation it presents. The very chronic indurating forms are sometimes called " sclerotic myelitis," or " focal sclerosis of the cord." From the various areas of inflammation secon- dary degenerations proceed, ascending or descending, and these may complicate the aspect of the disease- — a fact which has not always been sufficiently considered in interpreting the morbid appearances. Symptoms. — The symptoms of chronic myelitis vary much according to the character of the morbid process. For the most part they cor- respond in character to those that are produced by acute inflamma- tion, differing, however, in their mode of onset. It is therefore not necessary to repeat them in detail. Different cases may manifest almost every symptom that can be produced by disease of the spinal cord. There may be various motor and sensory paralyses, contrac- txires, and even muscular atrophy, but their common feature is their gradual, and often successive development. In the most common form, focal myelitis of the dorsal region, partial or transverse, the symptoms are paraplegic. They differ but little whether there is a single area of disease, or whether several foci near together implicate adjacent structures. Motor power is usually impaired far more than sensi- bility. Subjective sensations are often prominent and early symptoms, whether there is anaesthesia or not, — tingling, " pins and needles " in the legs, a sensation as if fur or wool covered the skin, sometimes with dull pain in the legs and back, especially after exertion, and commonly also with a well-marked girdle pain at the level of the chief lesion. Some loss of sensibility, partial in kind or in seat, will often be found if carefully searched for, but there is not often absolute loss of sensa- tion except in the rare cases of intense local sclerotic myelitis, by which conduction may be arrested as completely as by a growth. The onset of the motor weakness is gradual ; many months may pass before the power of walking is considerably impaired. As the legs get weak, excess of reflex action is developed (unless the reflex struc- tures are damaged). The knee-jerk is increased ; foot-clonus occurs when the legs are in certain positions ; and a tendency to spasm gradually develops, and increases to the condition typical of " spastic paraplegia." The sphincters frequently share the impairment of voluntary power. Co-ordination of movement is sometimes affected, usually manifested as general tmsteadiness, and defect of equilibrium, rather than as pure ataxy. The symptoms may come on simultaneously in the two legs, or one may be affected before the other, and occasionally the paralysis reaches a high degree in one leg while the other still possesses fair strength. When one half of the cord is affected almost alone (as in the lesion shown in Fig. 109), there may even be a crossed paralysis of motion .and sensation. Chronic polio-myelitis is often regarded as a distinct variety, but much confusion has arisen from the fact. If chronic myehtis de- velops in the cervical and lumbar enlargement, muscular wasting is CHRONIC MYELITIS. 387 usually added to tlie other symptoms. Similar atropliy occurs also in the widely diffused form of chronic myelitis, in which almost all parts of the cord suffer, and it may, indeed, be the most conspicuous symptom. It is always irregular in distribution in these cases, and it may be combined with other symptoms, palsy and anaesthesia, also irregular in extent and seat. The muscular wasting varies in the rapidity of the development, according to the character of the inflam- mation, and there are corresponding variations in the relations to it of the loss of power in the muscles, and also in the electrical reactions they present. In very chronic cases there is a slow failure of electrical irritability to both currents ; in others of more rapid course the voltaic irritability persists longer than the faradic irritability, and there may be a distinct degenerative reaction. The symptoms may com- mence in the arms or in the legs, but they ultimately become general in most cases, and, according to the place of their commencement, may seem to have an ascending or descending course. Occasionally the disease begins in the dorsal region, and after a time, perhaps years, it spreads to the enlargements, and the muscular wasting is added. The course of chronic myelitis is usually slow and progressive. The symptoms often increase so gradually as only to attain a considerable degree at the end of two or three years. At any stage the progress of the disease may cease. The chronic course may be varied by occasional more rapid increase of the symptoms, due to subacute or even acute processes in the diseased parts. Every degree of chronicity is met with, and subchronic cases, in which the symptoms develop in the course of a few months, effect a gradation to the acute and sub- acute forms of myelitis. The duration of the disease varies from six months to ten years or more. Thus in one case the symptoms slowly increased during about seven years, and then became stationary, and the patient died twenty-three years after the onset. Diagnosis. — The diagnosis of chronic myelitis rests on the slow deve- lopment of symptoms indicating a random process in the spinal cord, i. e. a process which damages irregularly structures of various functions, and thus cannot be looked on as a " system disease." The maladies from which it has to be distinguished differ according to the seat and character of the inflammation. Dorsal transverse or focal myelitis may be confounded with compression of the cord, with a tumour in it, and with primary lateral sclerosis. The distinction from pressure rests on the absence of a cause of compression, such as bone disease, — especially the absence of the signs of a morbid process outside the cord, preceding those of damage to the cord itself, e. g. the pains that indicate irritation of nerve-roots. A tumour within the spinal cord also causes, in most cases, more irritation of the root-fibres than does chronic myelitis. If myelitis involves one half of the cord much more than the other, the symptoms may closely resemble those of an intra-medullary growth. But a tumour never causes much 388 SPINAL COED. damage to one lialf of the cord witliout interfering considerably with the functions of the other half, and the symptoms in chronic myelitis may be strictly unilateral. The distinction from primary spastic paraplegia, the so-called " primary lateral sclerosis," is often one of some difficulty. The motor state of the legs may be identical in the two diseases ; in each there is the same extensor spasm, and in each there is a slow, gradual, and apparently simultaneous onset of the weakness and spasm. The distinction is that in primary spastic paraplegia the symptoms are purely motor; there is no indication that the lesion extends beyond the motor structtwes. In chronic myehtis, on the other hand, there is such indication, either by the impairment of sensation, or by the presence of a girdle pain. This distinction is sufficient in the majority of cases. The distinction from insular sclerosis is in many cases difficult. By Oppenheim and others, hideed, it is asserted that most cases described as chronic myelitis are really cases of disseminated sclerosis. The presence of cerebral or bulbar symptoms would naturally suggest such a diagnosis in a given case. But in insular sclerosis any very obvious affection of sensation is unusual. The form that involves the grey matter has to be distinguished chiefly from pachymeningitis and degenerative muscular atrophy. In pachymeningitis the muscular wasting may be similar, but anaesthesia is usually much more considerable in range and in degree, and there is more pain in the limbs. If there are similar symptoms in both arms and legs, myelitis is far more probable than pachy- meniugitis, since the chronic inflammation of the membranes is less extensive than that of the cord. From progressive muscular atrophy, the chief difference is in the random distribution of the wasting, the absence of symmetry, and indications of irregular damage to other structures in. the cord, as the occurrence of pain and of loss of sensation. But it must be remembered that, by some authorities, most cases of chronic spinal muscular atrophy are regarded as due to chronic myelitis. Eor the distinction from other less common diseases, the reader must be referred to the description of them. Like all other organic diseases, cases without wasting of the muscles, occurring in females, are often regarded as " hysterical paraplegia ; " the distinction rests on the points already described. It is, however, one of the diseases in which the least excusable er. ors m diagnosis occur, and in which their effects are often the most disastrous. Prognosis. — Chronic myelitis is a very grave disease, on account of the intractability of the morbid process, its frequently progressive tendency, and the persistence of damage which is slowly produced. But cases vary widely, especially in the two former features, and it is a disease in which general prognostic rules can scarcely be formulated. The observed tendency of an individual case is alone a trustworthy guide. Arrest of the disease is often obtained, but actual recovery CHEONIO MYELITIS. 389 is rare. The prognosis is little affected by the seat or extent of tLe process, except that the implication of the grey matter of the enlarge- ments is generally an unfavorable indication. The severity of the lesion, as shown by the degree of the symptoms, is significant chiefly in cases of long duration, and is subordinate to the course and mode of onset. If it can be arrested, the prospect of improvement is better in proportion to the slowness with which the disease has developed and the shortness of the time the symptoms have lasted. In general, more- over, the prospect is better, the fewer the foci of inflammation, in males than in females, and in cases of uniform than in those of recurrent or relapsing course. Preceding syphilis does not materially modify the pi'Ognosis ; hence the great importance of the diagnosis from syphilitic -growth, in which suitable treatment has a most certain effect. The ultimate danger to life is least in focal myelitis in the dorsal region ; it is greatest in the disseminated form, especially in the less chronic cases with a tendency to sloughing of the skin, and in the more chronic forms with muscular wasting. The indications drawn from the invasion of the respiratory muscles, and from the presence of any of the complications that so often terminate life, are the same as in other diseases of the cord. Tkeatment. — The first and most important measui-e is the improve- ment of the general health, by rest, change of air, and tonics. All ■causes of physical and mental depression must, as far as possible, be removed. Over-exertion, and even fatigue, should be avoided, and the patient should be kept, as far as possible, from exposure to cold. Absolute rest for a short time is often useful at the outset of the treatment, especially when there has been a somewhat rapid develop- ment of symptoms. In cases of purely chronic course absolute rest should not be maintained for more than a few weeks, or the patient may find it hard to regain his former muscular power. Counter- irritation at the situation of the disease is often useful, and most so in cases in which there is spinal pain or tenderness. Repeated siaapisms or blisters may be employed, but a mild form of the actual cautery is on the whole the most useful. A superficial bum or even slight vesication is sufficient on each side of the spine opposite the affected part, and it is best effected by means of the Paquelin cautery. It should be repeated as soon as the skin has healed, and if linear cauterisation is adopted the fresh line can be made beside the old one. A hot douche to the back, at a temperatvire of 103° or 104" F., applied daily, has been strongly recommended by Brown-Sequard. Warm brine baths, and various thermal mineral waters, have been also said to do good. A sea voyage is often of service, combiaing as it does the maximum of fresh air with the minimum necessity for exertion. Drugs, Tinfortunately, often fail to influence the morbid process, but nevertheless they are occasionally useful, so as distiactly to justify their careful trial in most cases ; and it is important to remember that those that are useless in one stage or period of the disease may yet be of S90 SPINAL CORD. unquestionable service at another stage. Tonics, as quinine and iron» should be given if indicated. Most of the measures recommended, and precautions advised, in the treatment of acute myelitis are needed in the chronic form, and it is therefore superfluous to repeat them. Those drugs that most deserve a trial are arsenic, small doses of mercury (such as -^ gr. of the red iodide), and iodide of iron. Energetic mercurial treatment rarely does good, even when the patient has had syphilis, and sometimes it does harm. ■ Iodide of potassium seems to have little influence on the disease. Nitrate of silver, ergot, and phosphorus have been recommended. Strychnia is chiefly useful in cases in which there is muscular wasting, but is of far less value than in the degenerative muscular atrophy. The treatment of other symptoms is that suitable in primary spastic paraplegia or progressive muscular atrophy, and described in the account of those diseases. COMPRESSION OF THE SPINAL CORD. Compression of the spinal cord is a common consequence of various morbid processes. Inflammation is almost always excited by the pressure, and intea-ference with function occurs, partly from the pressure and partly from the resulting myelitis. The symptoms pro- duced have, in different cases, many characters in common, although they vary according to the mechanism of the compression and the acuteness of the inflammation. It is only when there are indications that an acute myelitis has damaged the nerve-elements that we are justified in regarding the interference with function as an effect of the inflammation. Causes. — The morbid processes that may compress the cord are those that involve an encroachment on, or occupy part of, the vertebral canal. The chief are the following: — Disease of the bones of the spinal column, especially caries ; growths in the spine ; aneurism eroding the bones and then compressing the cord; growths in the membranes; thickening of the dura mater. These processes have usually only a small vertical extent, and the pressure they exert rarely extends over more than a few inches. Pathological Anatomy. — The cord usually presents evidence of the compression it has endured in considerable narrowing at the spot, where it may be indented and flattened, or cyhndrical. Sometimes the reduction in size is extreme ; for an inch or so the cord may be reduced to one third of its normal diameter, and it has even been found no thicker than a crow-quill. An example of flattening is COMPRESSION. 89] /' C •hewn in Fig. 110. On the otlier hand, there is sometimes very little narrowing to be discerned. At the compressed part the cord is usually red in tint if the com- pressio i is recent, but grey if it has lasted for some time ; its consistence is lessened in early cases, and increased in those of long duration. The change in colour and con- sistence is due to the inflammation of the substance of the cord which always results from pressure, and may often be traced for some distance above and below the com- pressed part. When there is much com- pression there is always much inflammation, but considerable myelitis may occur when the amount of compression is slight. The inflammation may be chronic and slow, developing in proportion to the pressui-e, or it may be subacute or acute, even when the pressure is gradual. The signs of inflam- mation are very distinct on microscopical examination, and resemble those in other forms of myelitis. There is a general in- crease in the interstitial tis-ue ; in this, at first, various cell-forms may be found, but it ultimately presents the appearance of a dense reticulum. The nerve-elements un- dergo degeneration, and abimdant masses of myelin, granule corpuscles, and corpora amjlacea are visible in the fresh state or in glycerine preparations of the hardened cord (Fig. Ill, c). Many nerve-fibres per- sist, however, with a narrowed sheath of Fia. 110. — Compression of the spinal cord and pres- sure-myelitis, in a CHse of caries of tlie spine. D, mid-dorsal region, m ar the chief point of greatest compression; the cord is narrowed from before backwards, and is uniformly damaged by inflsim- mation, so that the gr. y sub.-tance can ? cavc' ly be distinguished. C, 1^ inches higher up, sliows a slighter degree of myelitis, still extending through the whole thickness of the cord. B, first dorsul; the myelitis is much slighter and the chief disease is in the posterior columns, in which ascending degeneration occupies the post.-median columns and extends outwards into the post.-external columns. E, 1^ inches below the point of greatest pressure ; infl-.immation still extending througli all the elements of the cord. F, 2 inches lower down, shows only descending degeneration in the pyramidal tracts, anterior and lateral, and also the "comma-shaped" descending degeneration in the anterior part of the post.-external column. In G, at the lowest part of the dorsal region, the comma- shaped degeneration has ceased, and only that of the pyramidal tracts remains. (From preparations by Dr. F. G. Penrose.) 892 SPINAL (JORD. myelin, and it is probable tbat these regain tbe power of conducting, in spite of tbe persistence of considerable, and even dense sclerosis in ::?s^r «?• :'*-;" '^'o Pia. 111. — Pressure-myelitis; portions of the section D in Fig. 110 more highly magnified. A, from the grey matter, numerous angular and fusiform cells; vessels with walls thickened by a growth of cells, nar. rowing the cavity, which in some is obliterated. B, from the white columns ; thickening of the interstitial tissue, nerve-fibres in part destroyed, in part narrowed J a vessel with thickened walls. C, glycerine preparation from white substance ; abundant products of degeneration of the nerve-fibres, in part aggregated into granule masses. D, section of a nerve-root passing by compressed area ; increase of interstitial tissue, many nerve-fibres narrowed, some with swollen axis-cylinders. the part. In extreme cases all the fibres seem to be destroyed at the point of chief compression, but there is never an actual division of the cord itself. The grey matter can scarcely be distinguished from the white, even with the microscope, and the ganglion-cells become shrunken and atrophied. The walls of the small vessels are often thickened by spindle-cells, disposed more or less concentrically to the cavity, which is encroached upon and may be obliterated (Fig. Ill, a, b), a process that must add to the degree of damage to the cord. The signs of inflammation gradually lessen above and below the compressed part, but often extend for some inches in each direction. Beyond its limits the usual ascending and descending degenerations may be traced (Fig. 110). The nerve-roots passing by the seat of compression suffer from the pressure, and from interstitial inflammation excited in them. They are usually grey in tint and ultimately waste, and may even be reduced to fibrous threads. The microscope shows increase of the interstitial tissue, wasting of many nerve-fibres (Fig. Ill, d), and enlargement of some axis-cyhnders. COMPEKSSION. 893 Symptoms. — The effects vary much, according to the degree of pressure, its rapidity, its direction, the amount and character of the inflammation produced, the amount of damage to the nerve-roots, and the position of the disease. The symptoms in most cases enable the fact of slow compression to be inferred, even when there is no indication of the cause. They are of two classes : (1) interference with the function of the nerve-roots at the level of the morbid process ; (2) interference with the functions of the cord itself. The cord symptoms consist chiefly in impaired conduction, manifested in the j)arts below the lesion. The central functions of the cord (reflex a,ction, &c.) at the level of the lesion are abolished by the pressure, but the symptoms of this abolition are often lost in those of the damage to the nerve-roots. Of the root symptoms the most constant is pain, extending along the course of the nerve-fibres, and through the area of their distribu- tion. The seat of these pains depends on the position of the disease ; they may be felt in the arms, around the thorax or abdomen, or in the legs. They are usually sharp pains, resembling neuralgia in character, sometimes accompanied by tender points. Occasionally, when felt in the limbs, they are referred especially to the joints. The pain may be intermitting or constant. It may even be absent, as in a case of aneurism of the arch of the aorta already referred to. It may exist alone, for a long time, in a disease that increases slowly, and sometimes may be the only symptom, although some compression of the cord occurs. With it there is usually hyperaesthesia of the skin, often intense. After a time anaesthesia develops in irregular areas, in spite of the persistence of the pain, — the condition termed " anaesthesia dolorosa." Irritation of the motor nerve-roots may cause painful contracture of the muscles, but this is, on the whole, rare, and the chief motor symptoms are due to the interruption of the fibres — muscular weakness, gradual in onset, and accompanied by wasting. The rapidity of the atrophy varies much, and with it the electrical reaction. When slow, there may be merely a progressive diminution in irritability to f aradism and voltaism ; when rapid, there is often the degenerative reaction, and sometimes the " mixed form," from the partial damage to the fibres that supply a muscle. These local root symptoms are usually the first, and to them are added, after a time, the indications of interference with the function of the cord itself. There is weakness in the parts supplied from the cord below the lesion. The loss of power is usually gradual, bat sometimes comes von rapidly, even in the course of a few hours, when an acute myelitis is set up by the compression. With the weakness there is a marked and early increase in the superficial reflex action, more constantly conspicuous than in most other diseases of the cord, and therefore of some diagnostic importance. The myotatic irrita- bility is also increased, a foot-clonus being almost always present. Pains in the legs may occur, even when the disease is above the ■391. SPINAL CORD. lumbar enlargement, usually duU and aching. There is often formica- tion and tingling. There may be no impairment of sensibility in the parts below the lesion, even when there is complete motor palsy ; in many cases, however, there is some sensory loss, complete only when the spinal lesion is very severe. Conduction of painful impressions may be delayed, sometimes for thirty or even forty seconds. When the pressure is lateral, one leg may be first and most affected, but the other side is usually soon involved, since neither the mechanical effect nor the inflammation remain limited to one side of the cord. The sphincters are often affected. The tendency to the formation of bed- sores is rarely great, unless the lumbar enlargement is compressed or myelitis descends into it. The course of the symptoms varies according to that of their cause. When an acute myelitis has been set up, improvement may occur for a time even if the cause of pressure is slowly progressive. This is true also of root symptoms when they are rapidly developed. If the compression ceases to increase, the cord may recover its conducting function, although it remains narrowed. Sensation is often regained in the legs when motion remains absent, but both motion and sensation may be regained although the narrowing of the cord persists. It has even been found no larger than a goose-quill at the compressed spot, although the paraplegia had passed away. In such a case many narrowed nerve-fibres are found in the section of the compressed portion, and it is probable that many axis-cylinders persist, with an envelope of myelin so narrow as to be recognised with difficulty, but which sufiices for their conducting function. Under slow pressure the axis-cylinders may not suffer interruption, although the myelin dis- appears. Eegeneration of axis-cylinders, as in the peripheral nerves, is also possible. In some cases, especially when a considerable myelitis has been set up, the motor path may recover, but the posterior colunmB remain affected, so that power returns, but without co-ordination,^ " secondary ataxy " resulting. The Diagnosis of slow compression rests on the root and cord symptoms already described, and especially on their coincidence with a cause of compression. Of the former, the sensory symptoms are the most characteristic. In many cases other indications of the compressing disease assist the diagnosis. These vary in character j the most frequent is considerable local tenderness of the spine. If root symptoms are absent the diagnosis is much more difficult, unless the morbid process manifests itself externally. If there is a suspicion of compression in a case of slow paraplegia, an early and considerable excess of superficial reflex action gives additional weight to the suspicion. Even without any other symptoms to indicate com- pression, this is suggested by symptoms which begin on one side and gradually spread to the other. The chief disease from which compression of the spinal cord has to be distinguished is a subacute or subchronic transverse myelitis. ACUTE ATEOPHIC PAEALTSIS. 895 Besides tlie indications of a cause of compression already mentioned, the chief distinction def^ends on the presence of symptoms indicatiug irritation of the nerve-roots, and especially on the fact that these sym- toms precede those of the lesion of the spinal cord itself. Although a very chronic myelitis is occasionally attended by much irritation of the nerve-roots, the symptoms of this succeed, instead of preceding, the damage to the cord, and the course of chronic myelitis is often much slower than is that of most forms of sluw compression. The distinction from a growth within the spinal cord rests chiefly on the early occurrence of impairment of the central and conducting func- tions of the cord, and also on the partial distribution, and often slower course, of the symptoms. The effects of an intra-medullary growth vary widely in different cases, and if there is an early irritation of root- fibres, the distinction may have to depend on the presence or absence of the signs of an external compressing process. The diagnosis of the cause of compression is often much more difficult than that of its occurrence The facts that the patient is in the first half of life, and that he inherits a tubercular tendency, suggest caries. Slightness of root symptoms is also in favour of caries or a tumour within the spinal cord ; the presence of these symptoms does not, however, render caries less likely, unless the pain is extremely severe and is greatly increased by movement, — characters that should always suggest a growth in the bones of the spine. Eoot symptoms extending over a considerable vertical area suggest pachymeningitis. Additional details of the differential diagnosis will be found in the account of the several compressing diseases. Peognosis and Teeatment. — The prognosis depends on the cause, and the amenability of this to treatment. As a general mile, however, the more rapidly the cord symptoms develop, the more chance there is of improvement, because the greater share does inflammation take in their proc!uction. The treatm.ent is that of the cause of the com- pression, and that of myelitis. ANTERIOR POLIO-MYELITIS; ATROPHIC SPINAL PARALYSIS. In certain diseases of the spinal cord, wasting of the muscles is a prominent symptom. In these the lesion involves, exclusively or in part, the anterior grey cornua, and the muscular atrophy depends on the destruction of the nerve-cells, from which the motor nerve-fibres proceed, and on the consequent degeneration of the fibres. The mus- cular wasting does not depend on the nature of the lesion ; it ocears equally whether the nerve-cells are destroyed by haemorrhage, by in- 896 SPIXAL COHD. flammation, acute or clirorLic, by slow degeneration, or "by presstire. But tlie rapidity -witli -wliich tlie destruction occurs influences tlie character of the symptom. Time is required for the change in the nutrition of the muscles ; one or two weeks elapse, even in the most acute cases, before wasting is distinct. The nerve-cells also form part of the voluntary motor path, and their disease at once interrupts this ; hence, in acute cases, paralysis is rapidly developed, and the atrophy succeeds it after an interval. In chronic lesions, on the other hand, the changes in the cells and muscles progress so slowly that the weakness and wasting appear to come on together. The wasting may even seem to precede the weakness, but a careful examination will show that power is defective as soon as there is distinct atrophy. It is customary to separate the two groups by terming those in which the palsy precedes wasting, " atrophic spinal paralysis ; " and those in which wasting is apparently simultaneous with weakness, " spinal muscular atrophy." The atrophic paralyses are due to an acute or subacute process m the anterior cornua. The lesion is probably, in most cases, inflamma-- tory in character, a cornual myelitis, or " polio -myelitis " (Kussmaul). In some cases, which differ chiefly in the suddenness of the onset, it is probable that the lesion is haemorrhage and not inflammation. The chronic atrophies are due to a slow degeneration of the cells and fibres. Between the two forms, however, we meet with others of inter- mediate course, subacute or subchronic, due to processes of correspond- ing character, — ^usually inflammation. Acute Atrophic PAHAiiTsis ; Acxttb Anteeioe Polio-mtblitis. Infantile Paralysis ; Essential Paralysis of Children. Acute atrophic paralysis is a disease in which voluntary power is lost in the course of a few hours or days, and in wliich some of the paralysed muscles undergo rapid wasting while others recover. The onset of the palsy is often preceded or accompanied by indications of general disturbance. The muscles which waste usually remain weak, and contraction of their opponents may lead to permanent distortion of the paralysed limbs. Although it is usually a form of acute myelitis, its characters and course are sufficiently special to make its separate consideration desirable. The disease is the most common form of paralysis in young children, and has hence received the name of " infantile paralysis." Before anything was known of the lesion on which it depends, it received (from EiUiet and Barthez) the unmean- ing designation of the " essential paralysis of children," a term that is falling into merited disuse. The spinal lesion was first demonstrated by Prevost (1865), and soon afterwards by Lockhart Clarke and by Charcot and Joffroy. Its constancy has been abundantly proved by numerous observations during the last thirty years. The occurrence of ACUTE ATEOPHIO PARALYSIS. 397 similar symptoms in adults was noted hj Yogt (1858) and Duclieime (1864). Etiology. — The disease occurs at all ages, but is ten times as frequent in the first decade as ia all the rest of life. It is, moreover, especially a disease of later infancy. Of the cases in early life, three fifths occur in the first thi-ee years of life, nearly one fifth in each year. The numbers in each successive year (of 214* cases of which I have notes) were — ia the first 54, the second 58, third 39, fourth 17, fifth 23, sixth 8, seventh 4, eighth 6, ninth 5. Of the cases that begin during the first year, nearly all begin in the second six months ; the earliest of the series occurred at two months, but one at the twelfth day is described by Duchenne. The friends often date the disease from birth, but there is no real evidence of its intra- uterine development. After childhood it is most frequent between ten and twenty, and very rare over forty. One case, however, occurred at sixty-three. Many supposed subacute cases in adults have been examples of multiple neuiitis. In childhood the two sexes suffer nearly equally (males 133, females 103, in 236 cases), but after ten the malady is almost confined to the male sex. The influence of heredity is small, but a family tendency to suffer may now and then be traced ; two and even three brothers or sisters have been affected (Seeligmiiller, &c.). One of my own patients had a sister, and another two cousins, affected with the same disease. When more members of a family than one are affected, they usually suffer simultaneously. The inherited tendency may be indirect; of a patient in whom the disease came on in adult life, two brothers had suffered from hemiplegia and an uncle from paraplegia. The disease presents a remarkable relation to season, occurring far more frequently ia summer than in winter. Sinkler, who first called attention to the fact, found that in Philadelphia four fifths of the cases commenced in the five hot months. May to September. In this country the relation is equally apparent ; three quarters of the cases occur during the hottest third of the year, June to September. The distribution of 160 cases was as follows: — 3 occurred in January, 5 in February, in April 2, May 3, June 22, July 32, August 37, September 25, October 15, November 8, December 8. In many cases the weather was very hot at the time ; in some, however, the disease came on in cooler weather after a hot period. It would therefore seem that the heat generally acts as a remote cause, and is only occasionally concerned directly in the exciting mechanism. The fact is the more important because cold has long been regarded as the most potent exciting cause. That exposure to cold is an occasional cause is certain, although the number of cases in which it can be traced is not large ; and it is usually a general and not a local exposure, and has not often been immediately preceded by exposure to heat. Exceptions are * of these 214 cases 116 were seen and analysed by Sir W. Gowers, and 98 by Dr. James Taylor. I'hey include both hospital and private cases. 398 SPINAL COED. chiefly met with in adults. Thus one patient, aged sixteen, when perspiring from a long ride after the hounds on a hot day in September, lay down on a sofa beneath an open window from which a draught blew on his back. Two days afterwards the first symptoms com- menced. In another case the onset followed a day on a steamer in cold, wet weather, preceded by much paddling in the sea during extreme heat. I have several times known the disease to be due to sitting on damp grass. Two or three days is the interval which usually elapses between the exposm-e to cold and the onset of the symptoms, but great variations are met with, and the constitutional disturbance may commence within twenty-four hours of the exposure. Over-exertion in walking seems occasionally to aid in exciting the disease ; in some cases the child has walked far more than was proper the day before the onset, and in others habitual over-exertion has been permitted. A traumatic influence, such as a fall, occasionally pre- cedes the onset in such a way as to make its influence probable. Thus, in one severe case, a boy eight years old was thrown over the head of a donkey, and the onset occurred five days afterwards. A girl of fonr fell off a chair, striking her head, and was stunned for a moment ; two days later she was sipk and feverish ; the temperature (101°) continued raised till the sixth day, when general loss of power was. found, and the residual state was atrophic palsy of both legs and the right deltoid. The cases following falls and over-exertion present the same relation to season as do the rest. There is no proof of any relation between the disease and the process of dentition. The period of dentition coincides with the rapid functional development of the nervous system which succeeds its structural development in the first few months of life. Moreover this period is often one of deterioration of health, in consequence of changes of diet and other causes. The disease occurs before and after the period of teething, and it exhibits no increase in frequency at the period of the second dentition. Many children are perfectly well at the time when the disease occurs. A few are in conspicuously defective health. Thus in one case the child had been rendered feeble by long-continued diarrhcea. I have only once seen the disease in the subject of inherited syphUis. It has been thought to be occasionally secondary to acute febrile diseases, but the frequency of the relation has been unquestionably overrated ; in some supposed cases in adults there has been multiple neuritis only, and in children initial general disturbance is constantly mistaken for an independent general disease, and the opinion is often maintained after the discovery of the paralysis, which is then sup- posed to be of secondary origin. Thus in one case initial pyrexia, headache, and vomiting were supposed to indicate scarlet fever. Paralysis of all four limbs came on, with difficulty in swallowing, and the latter was supposed to render certain the diagnosis of scarlet fever, although there was no sore throat or rash. In older children ACUTE ATliOPHIO PAEALTSIS. b99 and adults tlie disease is often thouglit to be secondary to rheumatic fever, in consequence of the rheumatoid character of the pains. The error is the more likely to occur if the symptoms follow exposure to cold. It is conceivable that catarrhal affections may be produced by the exposure to cold which induces the disease ; but of the 214 cases referred to above, not one was related to any acute specific disease, or to rheumatic fever. Chronic alcoholism has been thought to be a cause in adults, but it is probable that most cases supposed to be due to this influence have been instances of multiple neuritis. Symptoms. — The general characters of the symptoms have been already mentioned — an acute onset, often with constitutional disturb- ance ; paralysis, at first wide-spread, afterwards passing away, except from a region in which the muscles rapidly atrophy, and in which, although partial recovery may occur, more or less weakness and wasting persist. The general disturbance, which is apparently due to a morbid blood-state, may be severe or slight. In most cases there is pyrexia, with its usual accompaniments, headache, prostration, loss of appe- tite, restlessness. Vomiting is very common, and often causes the illness to be mistaken for stomach disturbance. Occasionally there is also diarrhoea. These symptoms of general disturbance usually last for a few days, sometimes for only a few hours, and they are occasionally, but not often, absent. The palsy develops in most cases in the course of this disturbance. A common history is for a child to seem ill and feverish, to be put to bed, and the next morning to be found to have lost power. In other cases the febrile disturbance lasts for several days before the paralysis comes on. But the relation of the general disturbance to the onset of the paralysis presents great variations, which appear (from a comparison of cases) to be independent of any variations in, or special features of, the spinal symptoms. The constitutional symptoms occasionally succeed the onset. Thus a child, well one day, was found next morning to have both legs paralysed, and was feverish and sick ; the general disturb- ance continued for a week. The elevation of temperature is usually moderate in degree ; an example of its character, in what may be legarded as a fairly typical case, is that of a child whose tempera- ture on the second day of illness was 101"2° ; on the third, 101°; the fourth (on which the palsy developed), 100''; the fifth, 99-5°; the sixth, 98°. It is usually, as in this case, highest at the commencement, and sometimes reaches 103°, 104°, or even in rare cases 105°. The constitutional symptoms are present in most of the cases in which a fall appears to excite the disease, and are of the usual character ; they are as marked in the cases that appear to be spontaneous as in those that follow exposure to cold. Convulsions occasionally attend the onset, chiefly in young children. In soniP instances, moreover, the initial symptoms are those of sevei"© cerebral disturbance. Thus one child had repeated general convul- 400 SPINAL COED. sions during thirty hours, and afterwards was in a state of deep coma for thirty-six hours, the temperature at the onset "being 105°. This was succeeded by slighter pyrexia and prostration for three weeks, and it was only at the end of that time that general loss of power was found to have come on. The arms recovered, but atrophic palsy per- sisted in the legs. In another case, a child of seven months became ill, febrile (102-8°) and comatose with pin-point pupils; it remained ia that state for four or five days, and then gradually recovered, but with general powerlessness, rigidity of the legs, and tenderness of legs and back. The rigidity and pain passed away, but the right deltoid and, to a less degree, the biceps and triceps, and the whole of the right leg remained paralysed, and presented characteristic atrophy. In adults there is sometimes marked somnolence before the onset, and occasionally slight cerebral symptoms, such as diplopia, giddiness, or (very seldom) delirium. A medical student found, one day, that he saw double ; on the next day he felt giddy, and became feverish (102°) ; he slept for forty-eight hours, and on the fourth day found his right arm was weak ; atrophy of the deltoid, &c., followed. The cerebral symptoms usually pass away together with the indica- tions of general disturbance, and hence are probably due to the blood- statue, but occasionally slight facial weakness has persisted for several weeks. In rare cases the onset is accompanied by symptoms of slight transient spinal meningitis, which must be regarded as a coincident effect of the cause, since the membranes may be affected early. Thus a child, after being feverish and vomiting for two days, became universally rigid, so that strychnine poisoning was thought of. The rigidity passed away two days later, when the right arm and leg were found to be paralysed. Another child presented all the sym- ptoms of spinal meningitis a week after the onset of paralysis of the arm, and as they passed off the leg also was found affected. When the general illness is severe, the paralysis is often not discovered for some time, especially in a child ; the immobility of paralysis is often mistaken for the inertia of prostration. In older children and adults another common initial symptom is the pain already mentioned, sometimes referred to the muscles, some- times to the limbs generally, occasionally to the course of the nerves. It is often absent, but may be very severe and accompanied by extreme tenderness of the limbs. In such cases the pain may be supposed to be in the joints, because it is produced by moving them, when it is really in the nerves, which are mechanically disturbed by the move- ment of the joints. In these cases there is neuritis, which may come on at the same time as the palsy, although independent of it. The joints themselves may be the seat of pain, and, when the exposure to cold has been severe, inflammation of one or more joints has been known to come on soon after the onset. Pain may be felt also in the back, usually dull and achiag. It may be severe, especially when thei-e are symptoms of spinal meningitis. Instead cf being initial, pain in ACUTE ATROPHIC PARALYSIS. 401 the limits may succeed the onset of paralysis, and it occasionally con- tinues for several weeks, especially when seated in the nerve-trunks. In some cases in which the onset and course are characterised by severe pains, the motor effects have entirely disappeared in course of time, indicating that the condition was one of neuritis. Tingling or formication in the limbs may be described by older patients, but sen- sation is seldom affected, even temporarily. The paralysis is almost always rapidly developed. It varies much in its initial range. Only part of a limb may be affected, or there may be universal loss of power ; but in the majority of cases the para- lysis is intermediate between these extremes. Two or three limbs are affected — both arms, both legs, or the legs and one arm. When aU four limbs are paralysed the neck muscles also may be weak, and even swallowing may be impaired. The other muscles supplied by the cranial nerves escape, as a rule, and the sphincters are seldom involved. Occasionally there is retention of urine, sometimes incontinence, chiefly ia severe cases, and it may then last a long time. For instance, a child aged two and a half years woke up one morning with headache, fever, and weakness of the legs, which rapidly increased to complete paralysis. Four days later the arms also became weak, and in a day or two more the urine escaped involuntarily. The arms began to recover in six weeks, and were well in six months : both legs wasted and remained permanently paralysed ; the incontinence of urine lasted for a year. In another case, with incontinence for a few weeks, the residual palsy was in the lower legs. As in these instances, the symptom is met with chiefly when the lumbar region is diseased. The paralysis may commence in one limb and quickly spread, reaching its maximum extent in a few hours to a few days, but very often the actual onset is so rapid or so escapes careful observation in consequence of the general illness that all the parts first affected are found to be paralysed when it is discovered. Occasionally the onset is in two distinct stages, separated by a few days ; sometimes the loss of power develops slowly in the course of one or even two weeks, in cases that must be regarded as " subacute," but do not differ in other respects from the ordinary form. Examples of the common onset have been already given ; as another,. may be mentioned the case of a boy, aged a year and four months, who one day seemed ill, was sick, and was put to bed. The next day he could scarcely stand alone ; on the following day he could neither move the legs nor sit up in bed. In about ten days the left leg began to improve, but there was enduring paralysis and wasting of the whole of the right, and of the lower part of the left leg. In another case, a child seemed Ul, and was kept in bed for five days ; on the third day it was noticed that the left arm was not moved so much as the right, and by the fifth day the arm was quite powerless ; at the end of a fortnight improvement commenced. In the adxdt, the mode of onset presents nearly the same characters. A lady, twenty -five years of age, sat down for some time on wet grass^ VOL. 1. 26 402 SPINAL COUD. Two days later general rheumatic pains came on, "wlaicli were very severe in the legs on the following day, and the legs were distinctly weak. In the course of the next forty -eight hours the arms also became feeble, and at the end of a week she could scarcely move her arms, and her legs were absolutely paralysed. In a fortnight improvement commenced, first in the arms and then in the feet ; but the hip and thigh muscles remained paralysed and rapidly wasted. Cases are sometimes seen similar in other respects to those now under consideration, but in which the paralysis comes on suddenly, and without general disturbance. Thus a child, aged two, was walking along, when he suddenly could not stand, and fell down on his knees ; both legs were powerless. Slow improvement followed in the left leg, and wasting in the right. The suddenness of the onset makes it probable that the lesion is haemorrhage, and not simple inflammation. Spinal haemorrhage is known to occur in early childhood. Hence, while we must class these with the other acute spinal atrophies, we are not justified in regarding them as cases of polio-myelitis, since we do not know whether the haemorrhage is secondary to commencing inflam- mation or is primary. The former is probable, because the two sets of cases occur under the same general conditions of onset, and hence they cannot be separated. Moreover, constitutional disturbance is more often absent in cases of actually sudden onset than in others, although it is sometimes considerable. Thus a child had been ill for two weeks, when, being able to walk about, it suddenly fell to the ground ; the left leg was found powerless, and the right weak. It is probable that a sudden onset is more frequent than is suggested by the facts that can be ascertained, since the palsy often comes on during the night or during rest ; for instance, in one case a child sat on a chair for an hour, when the left leg was found powerless. In some cases of sudden onset the initial palsy is universal, and in such cases as the following it is probable that a limited haemorrhage in the cervical region causes rapid pressure on all the adjacent structures, which afterwards recover from the effects of the pressure. A girl, aged seventeen, suddenly felt tingling in the left hand. In a few minutes the whole arm was powerless, and then the right arm became paralysed. She had a strange sensation at the back of the neck, and went upstairs ; as she was going up, her legs became weak, first the left and then the right. In less than half an hour from the time of the first symptom, there was absolute universal paralysis, with difficulty in breathing and in swallowing. Improvement (in the opposite order to the onset) commenced the same evening and was complete in about six weeks, with the exception of the muscles of the left forearm and hand, which rapidly wasted and were permanently paralysed and atrophied. Another girl, while walking across a road, suddenly felt a " sort of shock " as if someone had given her a knock between the shoulders. She became giddy, and instantly felt tingling in both arms, especially in the right, which became weak before she ACUTE ATROPHIC PARALYSIS. 403 had got to the other side of the road. "Ultimately the arms recovered, but permanent paralysis and wasting of the intrinsic muscles of each hand were left. The initial loss of power is as a rule far more extensive and severe than the permanent affection; iu a small number of cases the two correspond. But the extent of the early palsy, that of the enduring atrophy, and the relation between the two, vary extremely, so that no general or even common laws can be discovered. Indeed, in all features of the disease variability prevails to such an extent as to baffle attempts to describe them in general terms, and a better conception of the malady can be gained from such illustrative instances as are here given than from general descriptions. One general fact is unfortunately true of almost all cases, namely, that the palsy scarcely ever passes away entirely, and that where wasting occurs, wasting remains. After the paralysis has reached its height and ceased to increase or spread, whether the poiut is attained suddenly or rapidly or slowly, it remains stationary for a time, which varies from a few days to six weeks, and then lessens. The improvement occurs first in the parts last affected, and gradually spreads until, usually at the end of Erom one to three months, all parts have recovered except those which are to be permanently affected. In these the muscles are toneless and flaccid from the first, and in two or three weeks there is distinct wast- ing, which rapidly increases, until the shape of the limb is changed, and, in extreme cases, scarcely any of the volume of the muscle can ultimately be detected. In fat children the appearance of the limb may be less altered, and it seems that, in some of these, an interstitial growth of fat makes up for the diminution of muscular tissue. In older children and adults the muscles are often tender to the touch during the process of wasting. When the atrophy is distinct the muscles no longer contract to faradism, and, if the motor nerves are tested, they also will be found to have lost irritability. The change depends on degeneration of the nerves, and the muscles usually present the "degenerative reaction " in its characteristic form. The loss of f aradic irritability is distinct, in severe cases, as early as the end of the first week, and even by the fifth or sixth day. In a patient, for instance, who is Tiniversally, and apparently uniformly, paralysed, one or more groups of muscles may be found to have lost irritability, and in these we know that there wiU. be lasting paralysis and wasting, while the other parts will recover. In a severe case, in which the muscles most affected atrophy completely, the loss of faradic irritability may be permanent. The voltaic iiTita- biUty remains, increased in degree, for two, three, four, or six months, then slowly falls, as the muscular fibres themselves degenerate, and ultimately, at the end of one or two years, it disappears. It may, however, persist for a long time, if the fibres are stimulated by elec- tricity, — even for three or four years, although the paralysis remains 404 SPINAL COKD. absolute. In rare cases, electrical irritability quickly disappears, even to the voltaic current, from the destructive degeneration of the muscular fibres. More commonly, after six or twelve months, some faradic irritability returns. It may be slight, due to the recovery of a few fibres, insufficient in number to restore any bulk or power, but the new fibies which recover do so perfectly, so that the irritability becomes normal in degree, although the contraction which can be thus produced is very slight in amount. In other cases considerable recovery occurs, so that some power and volume are regained, although the muscles remain below the normal size. In the muscles which are weak but do not waste there is no degenerative reaction, although there may be slight diminution of excitability to each current. The paralysis, as a rule, is motor only. Sensation is impaired only in extremely rare cases (about 1 in 50), in which inflammation in the lumbar region is so intense as temporarily to impair all the conduct- ing functions- of the cord. Thus, in a girl aged five, in whom the permanent state was a symmetrical atrophy of all the muscles below the knees, with a slighter affection of the thigh-muscles and flexors of the hips, the initial general loss of power in the legs was accompanied, for a few days, by complete loss of sensation below the knees. In the similar but more severe case of a boy, aged four, in whom the lasting palsy was general throughout both legs, the anaes- thesia continued for two months. In many cases there is a history of temporarily disturbed sensation attending the onsd:, probably the result of oedema around the inflammatory area. When sensation is lost there is always incontinence of urine. Eeflex action necessarily ceases in the parts related to the affected muscles. That from the skin is at first lost where there is weakness, but it returns with or soon after the recovery of power in the less affected parts. Where there is persistent paralysis it remains absent. The myotatic irritability is lost in the same or even greater degree. For instance, no knee-jerk can be obtained if the extensors of the knee are affected even in slight degree. The loss depends on the interruption of the muscle-reflex centre by the disease in the grey matter. In rare cases of severe cervical polio-myelitis, the inflam- mation spreads beyond the grey matter to the lateral white columns ; there is wasting of the arms, but paralysis without wasting in the legs, and in the latter the myotatic irritability may be increased above the normal, so that the foot-clonus may be obtained. In the course of a few months, however, the condition of the legs becomes normal. A common effect of the disease is to retard the growth of the bones in the affected limb, so that these gradually become shorter than their fellows, and the difference in size increases with the amount of general growth. Hence, it is greater, the younger the patient at the onset of the disease. If one part of a limb is more affected than another, the ACUTE ATEOPHIC PARALYSIS. 405 corresponding bone suffers most in growth. Tlie effect is sometimes considerable, when the atrophy is slight. Seeligmiiller has described the opposite effect — an actual elongation of the bones, attributed to the fact that the growing epiphyses suffer traction instead of the normal compression, but this is extremely rare. Those joints that depend for their support on tendons which pass over them become lax when the muscles are paralysed, and the articular surfaces may be no longer kept together. Thus when the deltoid is wasted the head of the humerus may fall out of the glenoid cavity. The head of the femur may fall from its proper position in the acetabxilum, and actual luxation may occur when the paralysis of the muscles is unequal, and the less affected unopposed muscles undergo the secondary contracture immediately to be described. That of the abductors and rotators may cause infra-pubic dislocation, and that of the adductors iliac dislocation.* I have known the patellar tendon to be greatly elongated, from the unopposed action of the extensors of the knee, so that their contraction caused the patella to rise three inches above its normal position. f During the chronic stage of the disease there is great tendency to the occurrence of permanent shortening of muscles, with consequent displacement of the parts to which they are attached. Grave de- formities are thus produced. It occurs only when the several muscles acting on a joint are unequally paralysed ; the less affected muscles are no longer subject to the normal extension by their opponents, and hence gradually become contracted, and the contraction is fixed by tissue changes in them, so that they cannot be passively extended. It may occur in muscles which are unaffected, and it is uncertain how far it is favoured by a slight degree of paralysis. Posture also aids the production of those muscular contractions, and so also in the case of the foot does the relative shortening of the limb. Bedsores are almost unknown, even in the acute stage of the disease. A slight local elevation of temperature in the most affected parts has been observed in the early stage, but subsequently the affected limb is colder than the other. This is due, in part at least, to the want of the aid to the circulation which is, in health, supplied by the muscular action. The persistent paralysis may occupy the whole or part of one or more limbs. The legs suffer three times as frequently as the arms ; the respective percentage being 21 and 68. It is less frequent for both legs or for one arm to suffer, and still rarer combinations are those of both legs and one arm, of both arms, of the arm on one side and the leg on the other, while the rarest of all is the affection of leg and arm on the same side. The limbs on the left side of the body are more often permanently affected than those on the right ; the difference is • See Karewski, * Archiv f. klin. Chir./ Bd. xxxvii. t In a case shown me by Mr. Heather Bigg. 406 SPINAL CORD. greater in tLe leg than in the arm. The left leg is paralysed alone twice as often as the right. When the paralysis of a limb is incomplete, the part involved varies much in different cases, and as different parts of two or more limbs may be affected, the combinations of palsy which result are extremely varied. The grouping of adjacent muscles is sometimes distinctly that of functional association ; often it is random ; but the most frequent condition is to have an irregular affection of the muscles that are associated in the centre. While the grouping is that of function, some of the muscles are only slightly affected, and others suffer with them that are not functionally associated. In the legs, the paralysis, in very severe and fortunately very rare cases, may be absolute, involving all the muscles of both hmbs. Usually it is partial, and then the muscles below the knee suffer more often than those above the knee. The calf muscles are affected less frequently or in less degree than the muscles in front of the tibia or the peronei. Hence talipes equinus is a common defor- mity, and its occurrence is '^^M, i Fig. 112. — Old atrophic spinal paralysis. Talipes valgus iii the right leg from para- lysis of the anterior tibial ; t. varus in the left, from paralysis of the peronei. ^ Fia. 113. — Atrophic spinal para- lysis, affecting cliiefly the calf muscles, with resulting contrac- tion of the flexors of the foot, causing talipes calcaneus. aided by the shortening of the limb, in consequence of which the foot has to be extended to bring the ball to the ground. Either the tibialis anticus or the peronei may be more affected, with the result, in the former case, of tahpes valgus, in the latter of talipes varus. In the case shown in Fig. 112 the peronei have suffered most in the left leg and least in the right, producing an unsymmetrical but ACUTE ATROPHIC PARALYSIS. 407 I < - corresponding distortion of the feet. This affords an illustration of another fact, namely, that when there is a partial affection of both legs the paralysis may be unsymmetrical in the two. Much less commonly the calf muscles suffer more than the others, and there results talipes calcaneus, as in the case shown in Fig. 113, and the intrinsic muscles of the foot often suffer with those of the leg. In the thigh, the ex- tensors of the knee are affected more frequently than the flexors, and hence flexor contraction is Tery common, and may even cause subluxation of the joint. The flexors of the hip often suffer, generally with the extensors of the kaee. Less commonly the glutei are involyed, but never alone. In the arm, almost all the muscles are sometimes affected, as in the case shown in Fig. 114, but all are seldom entirely paralysed. The intrinsic muscles of the hand often suffer; either the thenar muscles or the interossei may be most damaged. An instance of such para- lysis of the interossei is shown in Fig. 115. The forearm muscles are frequently affected, but the supinators may escape when the other muscles are involved. The deltoid suffers more fre- quently than any other single muscle of the arm. It may be paralysed alone or in association with other muscles ; occasion- ally the deltoid, supra- and infra- spinatus, biceps, and supinators are all involved in the " upper arm type " of palsy of Erb* (see p. 111). But other muscles than these may be / ; Fjg. 114. — Atropliio spinal para- lysis, infantile form. Wasting of all the muscles of the left arm from the deltoid down- wards, and of the right ser- ratus magnus. Fig. 115. — Atrophic spinal paralysis (adult form) Mffccting the interossei and thenar muscles, and also the deltoid. • See a paper by Dr. Beevor, ' Med.-Chir. Trans.,' 1885. 408 SPINAL CORD. associated with. tLe deltoid. The irregularity of tlie grouping is sliown by the fact that the triceps is often affected with these muscles. In the case shown in Fig. 115 the deltoid and intrinsic muscles of the hand were wasted, and no' other muscles. The serratus magnus is occasionally affected as in Fig. 114; in this case, although the left arm had suffered severely, as the figure shows, on the right side only the serratus was involved. With the serratus, the upper part of the pectoralis major is sometimes associated in paralysis (as it is in normal function, see p. 37), the lower part being unaffected; it was so in this patient. The middle part of the trapezius and other scapular muscles are occasionally involved. The neck muscles rarely suffer, but the diaphragm is occasionally paralysed. Although the intercostals and other trunk muscles are so often weakened in the early stage, con- siderable permanent atrophy is very rare. Curvature of the spine is sometimes produced in consequence of the patient being allowed to sit up while the muscles are weak. It may be a lateral or an antero- posterior curve, according as the weakness is on one or both sides. I have met with considerable depression of the lower part of the wall of the thorax on the left side from paralysis of the intercostal muscles at the spot, perhaps combined with hindered growth of the ribs. The muscles supplied by cranial nerves are scarcely ever affected. I have once seen complete paralysis of one side of the face, associated with wasting in the limbs, in an otherwise characteristic case, and an instance of affection of the face and tongue has been, recorded by Pasteur.* The Course of the disease has been already sketched. There are (1) an initial stage of paralysis, rapidly increasing, often accompanied with fever ; the duration of this stage is from a few hours to a week or even more ; (2) a stationary period, which lasts for a week to a month ; (3) a stage of " regression," during which the palsy passes away, except from certain parts in which wasting occurs ; this regressive period usually occupies from one to six months ; (4) a chronic stage (overlapping the last), during which atrophy con- tinues ; slight improvement may occur, but contractures and de- formities are developed. The duration of this stage is indefinite, because, wherever muscular tissue remains and some voluntary power returns, this slowly improves, by increased development of the muscle under the influence of use, and this continues in slight degree for years. This gain is often, however, more than counterbalanced by th.e interference with growth, and by the occurrence of deformities. Even in the slightest cases complete recovery is extremely rare, and the limb remains smaller than its fellow. On the other hand, death from the disease is equally uncommon, and occurs chiefly in the early stage. It is not improbable that some children die from the • ' Lancet,' 1887, vol. ii. It is probable that when the cranial nerve nuclei are affected, the vital centres become involved in most instances, so that the patients do not survive. ACUTE ATEOrHin PAEALTSIS. 409 initial disturbance before its nature is recognised. Now and then death occurs at the end of the first weet or ten days, from universal paralysis or from some such severe cerebral disturbance as existed in the cases mentioned above, or as followed the spinal lesion in a case in which paralysis in the arms came on upon the lliird day of the initial fever and reached its height on the fifth day, farad ic irrita- bility being lost by the seventh in many muscles of the left arm ; a little rigidity of the neck then occurred, and on the tenth day the patient began to vomit, complained of increased headache, and had hallucinations ; on the eleventh day he became comatose and died. Bronchial catarrh is an occasional cause of death, when the respii-a- tory muscles are weak. Eelapses are very rare, and occur chiefly in the form of a separate later extension of the disease. Second attacks are almost unknown ; one instance only was met with in the series of 214 cases. Sequelae, beyond those mentioned as part of the symptoms of the disease, are also very rare. As a rule the general and nervous health of the patients, and the duration of life, are uninfluenced by the local palsy. In a few cases, however, some other chronic affection of the spinal cord has come on when the subjects of infantile paralysis have reached adult life. Progressive muscular atrophy has been several times observed to start from the paralysed limb, and even to be apparently excited by a fracture of the bone.* Acute and subacute polio-myelitis in adult life have also been observed as a sequel, and I have twice seen the symptoms of lateral sclerosis slowly developed, in one case at seventeen, in the other at twenty-eight. In the spinal cord of the subject of old infantile paralysis there seems thus to persist some disposition, slight though it be, to fresh disease, and the cases of lateral sclerosis mentioned show that the liability to disease is not limited, as has been thought, to the grey matter.f The altered structure of the bones has been known to facilitate their fracture ; in one case the bones in the affected limb were broken on three separate occasions (Dutil). PATHOLOGiCAii Akatomy.— For a long time, infantile paralysis was believed to be a peripheral affection, having its seat in the muscles. But improved methods of examining the nerve-centres have shown changes in the spinal cord which have the characters of an acute inflammation of the grey substance of the anterior horns. The correspondence between the infantile and adult forms makes it certain that the latter are, in most instances, of the same nature. Subacute atrophic para- lysis in adults has been found, however, to depend on disease of the nerves in some forms that were thought to be spinal, but in these the palsy is strictly symmetrical, and when it is irregular in distribution the disease is certainly identical with the infantile form. Observations on the changes in the spinal cord in the early stage • Raymond, 'Prog. Med.,' 1889 ; Dutil, 'Gaz. .Med. de Paris,' 1881. t Compare Ballet and Dutil, 'lievue de Medecine,' Jauuarj, 1884, (i. 18. 410 SPINAL CORD. ■^^T^'^vV-ffi^-,^ are few. A case recorded by Dr. D. Drummond, in all probability one of tHs disease, is by far tbe earliest on record, and is indeed the earliest possible.* A child, five years old, died after a few hours' acute illness. The spinal cord, in the region of the fourth and fifth cervical nerves, presented undue redness of the anterior grey matter. The vessels running from the surface to the cornu were distended with blood. The microscope showed distension of capillaries and minute extravasations in the grey substance, swelling of the neuroglial elements and of the ganglion-cells, which were granular with indistinct processes. Another important early observation is that of Dr. Charlewood Turner,t six weeks after the onset (Fig. 116). In this and other somewhat later cases, acute changes have been found in the anterior cornua, more advanced than in Drum- mond' s case. They are often widely spread in slight de- gree, and attain considerable intensity in one or more foci, usually in the cervical or lumbar enlargements or both. At these spots the anterior horn is softened ; sometimes there is hsemorrhagic infiltra- tion (Fig. 117), sometimes an actual cavity (Fig. 116, A, b). The microscope shows extra- vasated blood often massed along the vessels (Fig. 116, c), and scattered through the grey matter with other cells such as are met with in mye- litis. There are also granule corpuscles and other products of degeneration of the nerve- elements. These elements, and especially the motor nerve-cells, have almost entirely disappeared. Where the change is slighter in degree there is a leucocytal infiltration, a few granule corpuscles are seen, while the nerve-cells may be structurally intact, * ' Brain,' April, 1885. f ' Path. Trans.,' vol. xxv, p. £03. «% Fig. 116. — Acute anterior polio-myelitis in a child 2^ years old, six weeks after the onset. (After Charlewood Turner.) A. Section through the lowest part of the lumbar en- largement, showinsr a cavity visible to the naked eye, on tlie lett side. B. Lef i ante- rior half of the cord under a low magnify- ing power, showing destruction of almost the whole anterior cornu. c. Portion of anterior cornu in the upper part of the lumbar enlargement. Numerous corpuscles lie in thegninuliir protoplasm and reticulum of fine fibres. A small artery is encrusted with several layers of corpuscles and nuclei. ACUTE ATROPHIC PAEALYSIS. 411 but swollen and granular. Tlie morbid appearances may be con- fined to the anterior cornua, or may extend in sKghter degree into -^>-t^< Fig. 117. — Acute anterior polio-myelitis in a child 14 months old. Dr. F. E. Batten's case. The affection coimnenced in the lees, but there were electrical changes and paralysis in the arms as well. The child died suddenly on the fourteenth day of the illness. The section made and lent by Dr. Batfen shows marked engorgement of vessels, with occasionally actual extravasation, small-celled infiltration, and changes in the anterior horn cells. the adjacent lateral column, in which the nerve-fibres near the gr^ matter may undergo destructive degeneration, and other signs of 412 SPINAL CORD. inflammation maj be seen. Tlie posterior columns are always un- affected. In very severe cases there may be signs of slight local meningitis corresponding in position to the region chiefly affected. This region corresponds to the origin of the nerves supplying the muscles in which there is most wasting, and the anterior nerve-roota which arise from this part present the signs of acute degeneration. Such changes indicate a general or interstitial inflammation of the grey matter. But some observations have revealed only alterations in the motor nerve-cells, which have presented granular degeneration, the matrix between them being quite unaffected.* This suggests that there may be a form of polio-myelitis in which the changes are essentially parenchymatous and not interstitial. At a later period, years after the onset, the appearances presented accord with those described as commonly found in the early stage, allowance being made for the difference in time. The anterior cornu at one or more places is shrunken (Fig. 118), and in part stains Fl&. 118.— Atrophic spinal (infantile) paralysis. A. First lumbar; the left anterior cornu is smaller than the right, and its ganglion-cells have disappeared with the exception of the inuer group. B. Fourth lumhar; the whole left half of the cord is smaller than the other, in consequence of the diminution in size of the ant. horn. Of the ganglion-cells only a few remain, belonging to the an tero- lateral group. Similar changes existed throughout the lumhar enlargement.f deeply with carmine, in consequence of its nervous structures being replaced by connective tissue, in part less deeply in consequence of "granular disintegration" of the substance. The motor nerve-cells are absent, partially or entirely. Sometimes a few shrivelled cells remain, sometimes one or more groups may be unaffected ; or one or two nerve-cells of normal appearance may alone remain (see Fig. 118). Small foci of disease may be seen in the unaffected part of the grey matter, and in these the motor cells may be smaller than normal ; the intervening plexus may have perished. When one horn is much damaged, the other may merely present fewer nerve-cells than * Rissler, ' Nord. Med. Ark.,' xx. t For these sections I am indebted to Dr. H. Humphreys, of St. Leonards. The paralysis came on at one and a half years of age, two years before death, and involved most of the muscles of the lelt leg, those of the calf in greatest degree, so that talipes calcaneus had developed. ACUTE ATROPHIO PARALYSIS. 413 normal, with, perhaps a little condensation of the interstitial tissue. The antero-lateral column is usually lessened in size, and may present slight sclerotic changes, especially in a zone contiguous to the grey substance, whence thickened septa may radiate into the white column. This is apparently due to the extension of an intense inflammation of the grey substance to the adjacent part of the white column. Sometimes a slighter sclerosis can be traced through the lateral column ; this is seen chiefl.y in cases of long duration, and is probably secondary. With extreme damage to both cornua there may be ultimately great wasting of the white columns on each side.* In consequence of these alterations, the affected half of the cord is conspicuously smaller than the other, even to the naked eye, and the difference is greatest where the damage to the grey matter is most intense. The anterior nerve-roots at the most affected part are small and grey, and the degeneration of the motor fibres may be traced down the nerve-trunks. Often a few fibres present a normal appearance although the rest have perished ; possibly from the sym- pathetic system. The muscular fibres, in early cases, have been found narrower than normal, and in a state of granular degeneration, with an increase in the nuclei of the sheath and of the interstitial tissue. Grannies and pigment masses accumulate between the sarcolemma sheaths. In extreme cases (those in which all electrical excitability is early lost) the degeneration proceeds to complete disappearance of the fibres, the place of which is occupied by fibrous tracts, developed partly from the sarcolemma sheaths and partly from the interstitial connective tissue. It is common to find, here and there, a fibre presenting normal appearances. Sometimes fat accumulates in the interstitial tissue, so that the reduction in the bulk of the muscle may be less than that of the fibres. In slighter cases, in which partial recoveiy takes place, some of the fibres probably regain their normal appearance, even though they have undergone slight granular degeneration. Usually, however, many fibres perish ; those which recover are smaller than normal, and the original volume of the muscle is rarely regained. Although there may be a permanent increase in the interstitial tissue, this undergoes contraction and comes to occupy but a small bulk. Muscular fibres are often seen that are larger than normal, and this is not (as has been thought) a transient condition, for it has been observed seventy and forty-five years after the onset.f It is perhaps sometimes a true hypertrophy.^ The bones have been found not only shorter than normal, but also • See • British Med. Journal,' 1887, p. 187. t Joffroy and Achard, 'Arch, de Med. exp.,' 1889; Dejerine and Huet, 'Arch. de Phys.,' 1888. X Dejerine. It is said to have heen met with in muscles totally paralysed ; but it is doubtful whether ** total palsy " of a muscle excludes voluntary contraction of some fibres in it. *l4f SPINAL COED. smaller, vrith. their angles rounded, tlie compact substance more uniform, and tlie Haversian canals smaller (Jofcoy and Achard), The brain bas been almost always found normal. In one case with extensive paralysis, of long duration, some atrophy was found in the motor region of the cortex (Sanders). It is probable that some acute changes would be found in cases that die with the cerebral sym- ptoms already described. No observations have as yet been made on the acute primary poly- neuritis that seems occasionally to coincide with the inflammation of the cord, perhaps sometimes to exist alone without any cord affection.* It is probable that, in the cases in which the nerves are tender in the middle of their course, the sheath will be found inflamed, and only the motor fibres will present such signs of secondary degeneration as always result from the lesion of the cord. Pathologt. — Both the character of the lesion and its mode of onset suggest that it is inflammatory in the majority of cases. In rare instances, as already stated, the almost instantaneous onset makes it probable that the lesion is different in character, is vascular in its nature, probably haemorrhage. It is likely that these cases are really haemorrhagic myelitis, in which the usual initial vascular dis- turbance is so severe as to produce an extravasation. Signs of inflam- mation, do not precede the sudden onset. The symptoms are well explained by the pathological facts that have been ascertained, extended by the simple inferences that are indicated by the symptoms. The lesion interrupts the motor path, causing immediate palsy, which results from damage to the cells and nerve-plexus of the grey matter, whether slight or severe. The recovery of the slightly damaged structures restores the voluntary path, and even if the fibres from the cells degenerate, they seem to regain normal nutrition by regeneration when the cells recover. But when the motor cells are destroyed the fibres from these degene- rate permanently. As the slighter damage is usually far wider than the destruction, the initial palsy is more extensive than the persistent atrophy, and the extent of such is purely a matter of this relative area of trifling and severe degree of lesion. Nerve-cells that are destroyed are never renewed, and hence the permanence of the muscular wasting that dej)ends on such destruction. When a few nerve-cells escape destruction, a few nerve-fibres recover and a little muscle-tissue remains, too slight, it may be, to be of use. The occasional interference with the conducting tracts in the white columns is explained by the obvious extension of the inflammation, which, when very intense, may even spread through all the structures of the cord, as in the rare cases in which sensation, as well as motion, is lost. But such cases, which are most rare, differ from true transverse myelitis in the rapidity with * As was probably the case in two cases of paralysis in children shown to the Harveian Society of London by Dr. Leonard GuiLrie, 'Lancet,' 1897, voL i, p. 448. ACUTE ATKOFHIO PAIULYSIS. 415 wliich tlie damage restricts itself to its special seat, and sensory con- duction is restored. The fact that the disease of the sensory tracts is only secondary and trifling, is emi:)hasised by the fact that even in these cases th«re are never the acute bedsores that would surely ensue in a case of true transverse or total myelitis of corresponding seat. The observations mentioned on p. 412 suggest that there are two varieties of the inflammation of the grey matter, such as we have recognised, in myelitis generally; a parenchymatous inflammation consisting in a primary change in the nerve-cells, and an interstitial or general inflammation, as in the common forms of myelitis, in- volving the nerve-cells only as one of many structures equally damaged by a process that has no special relation to the nerve-elements. The distinction is important, because we should expect to find, in the former cases, a wider slight initial affection than in the others, and finally a more definite relation to function in the parts diseased. The true pathology of the malady, its relation to its causes, is still obscure. The one salient fact that we can discern, though scarcely define, is the evidence of a blood- state afforded by the general sym- ptoms. That these symptoms are not the consequence of the local inflammation is shown by their disparity in degree, and difference in time. It is probable, therefore, that the spinal lesion is not the cause of the constitutional disturbance, but is rather an effect of the cause of the latter. It seems impossible otherwise to understand the extreme variation in the two forms of disturbance. But we have no evidence as to the nature of the blood-state, and there are no other effects, commonly associated with the myelitis, to indicate the general patho- logical tendency of its cause. The closest analogy is with some forms of neui'itis, and this, as we have seen, may co-exist with the spinal lesion, as a consequence, at any rate, of exposure to cold. Indeed, it is probable that the inflammation of the nerves is the chief or even the only morbid process in some of these cases. On the other hand, it must be noted that in the epidemics of the disease, there were, besides cases of spinal cord disease, simultaneous cases in the same places in which the evidence pointed to an analogous inflammation in the cere- brum. In one epidemic, the American one, the lower animals also suffered (see p. 416) . The variations, alike in the general symptoms and in the inflammation of the cord, and especially the indications that the latter may be either parenchymatous or interstitial, suggest that the causal blood-state also varies in different cases. We have no indication of the way in which the remarkable relation to season is produced, whether by predisposing the individual or favouring the development of some toxic agent. We must, however, recognise as an essential element the predisposing influence of age, which we may associate with the facts that the structural development of the nervous system is complete, but the function of the nerve-elements must lack the stability that comes only from continued use, and that the period is generally that which coincides with the first serious demand on the 416 SPINAL CORD. functional energy of tlie grey matter of the cord. We may remember also the vascular activity that all function entails, and the readiness with which the vaso-motor system of children is disturbed. Lastly the occurrence of the disease in more than one member of the same family indicates a congenital disposition of the system to react in a similar manner to certain external agencies, while a special feature in the latter may perhaps explain the occasional epidemic character of a disease, and furnish grounds for ascribing to it an "infective" character.* The evidence available suggests that it is probably due to some chemical change in the blood analogous to that which seems to cause rheumatic fever, though probably distinct from it — a change excited by cold, disposed to by the effect of heat, the result of some derangement . of metabolism which we cannot yet understand, and perhaps having underlying these effects some organismal cause. This hypothesis does not exclude the action of traumatic influences in determining the disease. Such a glimpse of its pathological relations is all that we can at present obtain. Diagnosis. — This rarely presents any difficulty except in the early stage. When the initial paralysis is passing away, and the wasting is distinct, the nature of the case is sufficiently evident, and is cor- roborated by the electrical reactions, by the loss of reflex action, and by the absence of any impairment of sensibility. At the onset, however, the symptoms may readily be misinterpreted. The most common error is to attach too much importance to vomiting, and to regard the attack as simply gastric. G-eneral disturbance is naturally ascribed to some general cause "until nervous symptoms manifest themselves. Even then there is risk of error. On the one hand, as we have seen, a diagnosis of a general disease is not always relinquished when paralysis appears, but the latter is regarded as secondary. On the other hand, especially in young children, the existence of paralysis is often overlooked at first, and it is supposed that the child doi s not move because it is prostrate. This error will not be made if it is remembered that mere prostration seldom causes total immobility, and a fortiori it does not produce local immobility. When the pyrexia ceases, and the loss of power persists and increases, the existence of paralysis is always unmistakeable. The initial general disturbance must then be regarded as part of the disease unless there is the clearest evidence of its independent nature. In adults, the danger of mistaking paralysis for prostration is con- siderably less, but, on the other hand, the general symptoms are as likely to be misinterpreted as in the case of children. The rheuma- toid pains, which are so common, are usually regarded as evidence of acute rheumatism, especially when the affection follows exposure to cold. Whenever rheumatoid pains are not localised in the joints • See Medin, ' Neur. Cent.,' 1896, p. 1120 ; Buccelli, ' Neur. Cent.,' 1897, p. 798 ; Sowerby, ' Journ. Am. Med. Assoc.,' January, 1896; Pasteur, * Trans. Clin. Soc.,* 1897. ACUTE ATROPHIC PAEALYSIS. 417 and especially wlien they are spontaneous, and not influenced by move- ment, tlie possibility of tbeir spinal (or nerve) origin should be remem- bered ; and other indications of spinal mischief, such as local loss of power, tingling or formication, should be carefully watched for and receive due weight. Of other spinal cord diseases, all chronic lesions are distinguished at once by the onset. From other acute diseases, moreover, the dis- tinction is only difficult in the early stage. As soon as the initial palsy begins to lessen, and the muscles in one part lose faradic irrita- bility and begin to waste, the nature of the case admits of no doubt. The diagnosis may be made with certainty after the end of the first week by the electrical reaction. If we find loss of faradic irrita- bility, it is certain that the characteristic alteration in voltaic irrita- bility will follow. The isolated induced shocks should be used instead of the serial "current," because any harmful stimulation of the sensory nerves is thereby avoided. (See Diseases of the Nerves.) Acute transverse myelitis is only simulated when the inflammation of the grey matter is bilateral and so intense as to extend to the white columns, but the age of the patient generally suggests correctly the nature of the disease. The myelitis of childhood is polio-myelitis. The pseudo-transverse variety — polio-myelitis, transverse through its intensity — is seated in one of the enlargements, usually the lumbar ; the true transverse form usually occurs in the dorsal region. Eeal difficulty is confined to adults, in whom there is extensive cervical or lumbar myelitis involving the grey matter. In young adults, polio- myelitis is more likely ; this is indicated also by what is best described as a regressive onset in contrast to one that is progressive. In the former a wide extent is quickly reached, and the symptoms then tend to lessen ; in the latter the morbid process is a longer time reaching its height : in the former the symptoms clearly show that the most severe affection is of the anterior grey matter ; in the latter, severe anaesthesia or trophic disturbance usually points to an equally intense lesion of the other parts of the cord. The separation of subacute from acute myelitis of the grey substance is, to a large extent, arbitrary. The symptoms are similar, but the onset is less rapid and occupies more than a week. The distinction of multiple neuritis is from the subacute rather than the acute spinal atrophies, and is considered elsewhere. The diagnosis from paralysis of cerebral origin is usually easy. In cerebral palsy there is never loss of faradic irritability or extreme muscular wasting, or loss of the muscle-reflex action. In the spinal affection there is no trace of the mobile spasm that is common after infantile hemiplegia. Any cerebral symptoms which may attend the onset of polio-myelitis are subordinate in significance to the state of the muscles as evidence of the permanent lesion. Convulsions at the onset of infantile spinal paralysis are general ; those that result from a cerebral lesion are usually unilateral or commence locally. The chief VOL. I. 27 418 SPINAL CORD. difficTilty arises wlien arm and leg are inTolved on the same side. These cases are rare, and present no difficulty if attention is paid to the nutrition and reaction of the muscles. The exceedingly slow onset of pseudo-hypertrophic paralysis, developing gradually, as it does, with the child's growth, ought to render its confusion with polio-myelitis impossible. A reasonable doubt can only arise in a slight case in which the onset was unnoticed or forgotten. I have once tnown slight atrophic palsy of the exten- sors of the knee to induce the habit of putting the hand on the knee in rising from the ground — an action often thought to be peculiar to the pseudo hypertrophic disease, but acquired when weakness of the extensors occurs in early childhood from any cause. Diseases outside the nervous system which have been mistaken for infantile paralysis are chiefly those in which local pain interferes with the movement of the limbs, and the child is young. I have known, for instance, the mistake to be made in the case of hip-joint " disease, necrosis of the femur, and the affection termed " scorbutic rickets," in which there is enlargement of the shafts of the long bones, extreme pain on movement, and spongy gums. In all these cases a careful examination will show that movement is interfered with only by the pain ; there is no actual paralysis, and there is no interference with reflex action. The preservation of the knee-jerk is often of great significance ; it at once excludes atrophic palsy in any case in which, the extensors of the knee seem feeble. The points above described should always enable the diagnosis to be made. It is impracticable to enumerate the distinctions from every disease with which confusion is possible, for experience shows that there is no form of palsy with which a common disease, such as this, is not at some time confounded. Peognosis. — The danger to life is probably greatest when there is severe constitutional disturbance, which may even precede the develop- ment of the characteristic paralytic symptoms. In the stage of paralysis there is peril only when the chief disease is in the cervical region, and respiration is interfered with; but this danger is small imless an attack of bronchial catarrh is intensified by the palsy. Definite cerebral symptoms involve danger proportioned to their character and degree, but it is generally less in reality than in appear- ance. In the vast majority of cases the disease involves no immediate danger to life. But children are left with little power of resistance to other morbid influences, and occasionally succumb to some other iUness, as an acute specific disease, or an attack of bronchitis, a few weeks or months after the onset of the paralysis. As soon as the paralysis has become stationary, i, e. has not increased for twenty-four hours, the danger of further extension is small. But the question at once arises, and is anxiously asked, — What will be the permanent condition ? Will there be lasting paralysis ? An answer cannot be given until the end of the first ACUTE ATROPHIC PARALYSIS, 419 weeTc or ten days, and tlien only by means of an electrical examina- tion. Whatever muscles, at tlie end of that time, have lost faradic irritability will certainly waste, will remain for a long time paralysed, and will probably be permanently affected in some degree, slight or severe. On the other hand, if there is no loss of irritability at the end of ten days, but it is apparent at the end of a fortnight or three weeks, the wasting will be slighter in degree, and some ultimate recovery may be anticipated even in the most affected part. Where there is no loss of irritability the paralysis will pass away in the course of a few weeks, or at most of a few months. When faradic irritability is lost early and completely, the wasting will be rapid and great, and it is unlikely that there wiU be much recovery. The return of faradic irritability that has been lost is a favorable indica- tion; it signifies nerve-regeneration, and will be followed by an increase in voluntary power. Without an electrical examination it is necessary to wait longer before a prognosis can be given, imtil distinct wasting on the one hand, or improvement on the other, indicates the regions in which the paralysis will persist and in which it will pass away. Even then the prognosis cannot be so definite. In the chronic stage the prospect of ultimate recovery depends on the rate at which wasting developed, on the electrical reaction, and on the duration of the case. Where there is no sign of returning power at the end of three months very little recovery will occur; the nerve-ceUs are destroyed, their renewal is impossible. The preservation of voltaic irritability (that of the muscular fibres) is so far satisfactory that it shows there has been no destructive degeneration of the muscles ; and if voluntary power is increasing, it indicates favorable conditions for its exertion, but it does not lessen the grave significance of persistent palsy and the absence of faradic irritability, which indi- cate persistent nerve-degeneration. On the other hand, if, at the end of one or two months, some faradic irritability can be still detected, although low in degree (i. e. elicited only by a strong current), improvement is probable, and may become considerable. It is neces- sary, in the case of children, to remember, and it is important to warn the friends, that the growth of the most affected limb will be hindered, and that this, ia the case of the leg, may render the effect of the paralysis more obtrusive by its interference with the gait. Otherwise they are distressed by what seems to them an increase ia the disease, but is really compatible with continued improvement. Treatment. — The treatment of the acute stage of the disease is essentially the same as that of myelitis, already described, and the rules and principles already stated need not be here repeated. In the initial stage it should be that of the general state, guided by any special causal indications that may be detected ; such as free sweating, followed by salicylate of soda or salicin, in a case distinctly due to exposure to cold. We may hope that future observations will afford us some indications regarding the means of counteracting 420 SPINAL CORD. other blood-states that apparently exist at the onset, and are con- cerned in the production of the lesion. At present we are without this help, and can only treat the initial stage as we should any other local inflammation, directing our treatment to the symptoms that may be present, and the conditions that apparently underlie them. The child should be kept at perfect rest, on the side, so that the spine is not the most depending part. Warmth may be applied over the affected part of the cord by poultices or fomentations. The marked relief these give, when there is spinal pain, make it probable that they exert a beneficial influence in all cases. In such a disease — in which there is a natural tendency for the morbid process to cease to spread, and then to lessen in extent — the difficulty of ascertaining the effect of treatment on the lesion of the spinal cord is very great. Full doses of belladonna or ergot have been credited with the control and arrest of the morbid process, but only on the evidence of a coincidence in isolated cases, the value of which is small in a disease so irregular in its course. Either may appa- rently be employed, however, without fear of harm. But probably the measures mentioned above directed to the local inflammation have far more influence than drugs on the morbid process. As in all acute diseases of the nervous system, the chief room for effective treatment rests with the practitioners who see the cases in the early stage. When the acute onset is over and the spinal lesion has become stationary the careful management of the early stage should be con- tinued for a time, because a relapse or recurrence, however rare, is not entirely unknown. Such care is especially needed in cases in which the constitutional disturbance has been prolonged, or has continued after the onset of the spinal symptoms, or in which the latter have come on in distinct stages. Under these circumstances, perfect rest should be maintained for one or two weeks more. The same prolonged care is needed when there is persistent tenderness in the limbs, or any indications of an independent neuritis. Where wasting is taking place, some slight tenderness of the nerves and of the muscles must be expected to accompany the process, and this, being purely secondary in nature, does not call for special treatment. When the acute stage is over, and the condition of the patient is stationary or improving, tonics are generally both useful and needed, especially iron and quinine. Strychnia may be given in all cases, but it should be commenced only three or four weeks after the disease haa become stationary. Although clear proof of its utiUty is not forth- coming, and cannot indeed be expected in a disease in which merely damaged nerve-elements always tend to recover, the drug has a^ definite influence on the nutrition of the structures that are specially affected, and it is reasonable to suppose that it promotes their recovery, and is capable of rendering this greater. But an agent that has so ]>owerful an influence on function (and therefore on nutrition) is likely to do harm, rather than good, until normal conditions are ACUTE ATROPHIC PARALYSIS. 421 being restored. If functioii oannot respond properly to a stimulus, it is not likely that nutrition can be influenced aright. Hence, the more severe the lesion the longer time should elapse before strychnia is commenced, and the smaller the dose that should at first be given. It is probably never either necessary or desirable to give it by hypo- dermic injection in this disease. The disease frequently occurs at the age at which any illness causes the hindrance to general development that constitutes the condition known as rickets, and this fact should be remembered in treatment. In the case of children who are still in the period of the first denti- tion, it is, therefore, wise to anticipate the danger by giving, during convalescence, those agents that have most influence in counteracting the tendency, especially cod-liver oil and iron ; the lacto-j^hosphate of lime and iron is especially useful. The use of electricity is an important part of the treatment, although for reasons very different from those that first led to its use, and it is desirable that they should be clearly comprehended to secure its Tjenefit and prevent its harmful or useless employment. There is no evidence that it can or does influence the process of recovery of the damaged elements in either the spinal cord or the nerves. Moreover, as long as the nutrition of these is actively disordered, its stimulating influence is likely to increase the derangement rather than promote the restoration of a normal state. The reasons for its use depend on the fact that the disease entails nerve-degeneration, and are essen- tially the same as those that justify and determine its employment in other nerve lesions, and have been already explained. The muscular fibres whose nerves are degenerated suffer changes in nutrition, and ultimately perish if no nerve-regeneration occurs. While the influence normally exerted by and through the nerve-fibres is in abeyance, the muscles are destitute of this influence, and without any functional stimulation. If they are excited from time to time by electricity, their sensitiveness to stimulation is distinctly increased, and this not only to electricity, but to the voluntary stimulus. This is clearly shown by cases that have been untreated ; the muscles may not respond at aU to the first application, but when they have been galvanised two or three times a distinct contraction may be obtained, and, within a week, some voluntary power may return. Wherever cell and fibre have perished, nothing that electricity effects can be of service ; but where there has been damage, not destruction, and the nerve-fibres slowly recover, but regain their influence on nutrition, and their capacity for conveying impulses, only after some months, the failure of muscular nutrition may be disproportionately great, and may even render useless some regained nerve-power. This result electricity is probably able to prevent. It does not, as far as we can perceive, prevent or even lessen the visible wasting of the muscles ; it is powerless to counteract the effects of a destructive lesion ; but it does seem to hasten recovery from the effects of partial 422 SPINAL COED. damage, and to lessen fhe nltimate degree of this damage. It does so solely by its influence on the muscular tissue, and only voltaic elec- tricity can stimulate this tissue when the nerve-fibres are degenerated. The mode of application should be the same as for nerve lesions. The muscle is only stimulated when the circuit is interrupted, as by repeatedly stroking the muscles with one terminal (a sponge, or con- ductor covered with water-holding material, well wetted with salt and water), which should be lifted from the skin between each stroke. The other terminal is kept still ; it may be placed on the upper part of the muscle, where its nerve enters it. By some this terminal is placed on the spine over the affected region (and then a larger flat terminal is employed), under the impression that the electricity may influence the morbid process in the spinal cord; but there is na evidence even that the spinal cord is reached by electricity so applied. When applied to the muscles, the strokes may be made with the negative terminal, since each pole will influence the tissue, and the normally greater irritability to the negative often persists. The appli- cation can be made perfectly well by an intelligent nurse, since the diffusion of the voltaic current is so great that it is sure to reach the affected muscles. Each time the sponge is placed on the skin the affected muscles should be seen to move or swell up in slight contrac- tion, and it is desirable to use as many cells of the battery as wiU produce this result. Sometimes this cannot be done without causing so much pain as to distress the child, but in many instances the distress is really due to a needlessly strong and painful current having at some time been used, and an amount of alarm produced that the child never gets over. It is on this account that it is se important to make a test examination with great care, and to employ the less painful faradic shock. Emotional disturbance may generally be avoided by commencing with a very weak current. It is better, indeed, to commence with no current at all, applying the sponges in the way directed, so that the child may be familiar with them, and cease to fear them. Then two or three cells may be used, and the strength gradually increased day by day. In this way a current strong^ enough to cause contraction will often be tolerated. If, however, in spite of these precautions, this strength cannot be employed without distressing and disturbing the child, the attempt to obtain muscular contraction should not be persevered in, but only such a cui'rent employed as does not disturb the child. An influence on nutrition, if slighter, is still exerted, and if the application is con- tinued for a longer time it is probable that equal good is done. The electrical treatment may be commenced at the end of the fourth week after the onset. It should not be used earlier, lest it excite increased disturbance in the spinal cord. The application need only be made to those muscles in which faradic irritabihty is lowered or lost. Other mus- cles will recover without its aid, or will be uninfluenced by electricity. Another measure which should be employed is systematic rubbing ACUTE ATROPHIC PARALYSIS. 423 of tie limbs. This stimulates the circulation, which is always defec- tive, as the blue, cold surface shows. It no doubt also increases the movement of the fluids in the tissues outside the vessels, and so probably increases the interchange of material, and promotes nutri- tion. The muscles should be daily rubbed and gently Imeaded, upward rubbing being especially useful. No liniment is required ; the uncovered hand answers best. Cod-liver oil is sometimes rubbed on ; a minute quantity is probably rubbed in, without good or harm. Great care should be taken at all times to keep the affected limbs as warm as possible. In all cases in which the trunk muscles are weak, even in slight degree, bronchial catarrh must be guarded against with great care. In such cases the muscles of respiration are weakened, and although normal breathing may not be impaired, the diminution in strength may render an acute bronchial catarrh rapidly fatal, and this even, months after the onset of the paralysis. When some voluntary power is regained the systematic use of the muscles is of great service, and shoidd be carefully attended to. Systematic j)lanned movements may generally be adopted, and an improvement of muscular nutrition and power may be secured much earlier than if the limbs are left to the chance influence of such move- ments as a child spontaneously adopts. Most of the good that is done by "movement cures" may be obtained by such simple mus- cular exercises as can be readily arranged with the help of a little consideration on the part of the doctor, and can be efficiently carried on at home, given the necessary perseverance on the part of those who have charge of the patient, and which, unfortunately, is less often forthcoming. Such movements need to be specially arranged to meet the exigencies of each case, so as to call into action those muscles that are weak but not powerless, or that may supplement the muscles that are paralysed. A very important element in the management of the chronic stage is the prevention and treatment of the muscular contractions, and of the deformities to which these give rise. The contractions cannot be entirely hindered, but they may often be prevented reaching a high degree by careful attention to the position of the lim.bs, and by watching for and treating the earliest indication of shortening of the muscles. It is needless to discuss in detail the varied influence of posture in these cases ; careful and frequent examination of the patient will show whether any deviation from normal relations is being deve- loped, and its counteraction is chiefly a matter of common sense and a little practical ingenuity. Of especial importance, however, are the prevention of the curvatures of the spine which are caused by allowing the patient to sit up before the back muscles have regained the neces- sary power, and the prevention of the shortening of the flexors of the hip and knee joints that occurs when the patient is allowed to lie in bed with the legs drawn up. More difficult of prevention is the con- 424 SPINAL CORD. traction of the calf muscles, often aggravated in consequence of the lessened growth of the limb. Something may be done during the process of rubbing for the prevention of deformities. While the con- tracted muscles are rubbed upwards they should be extended gently but firmly. Thus, if the caK muscles are shortened, the foot should be steadily pressed upwards while the calf is rubbed. A slipper with elastic straps to a knee-band may be worn at night, often with great benefit. For developed deformities, due to great shortening of the muscles, surgical treatment by splints or tenotomy is usually necessary, and is often important because it enables the patient to use the limb in ways that would be impossible without it. For this and other reasons mechanical appliances are of unques- tionable value. Counteracting deformities and supplementing weak muscles, they often enable a child to walk who could not do so without their aid, and power is often increased to a rejnarkable extent in indirect ways. In all these cases, however, the instruments require frequent attention and alteration to adapt them to the changes due to growth, and patience is required in the management of these cases through their long and tedious course. Two facts deserve a final emphasis. At the end of six months all possible lecDvery is nearly completed, and certainly at the end of a year the lesion has become a cicatrix, and further improvement will be merely by the slow growth of the muscle that has recovered, under the stimulus of use. Secondly, this process of slow improvement as the result of use will go on for years, — will go on whatever treatment is adopted, and whether special measures are employed or not. The therapeutic specialist who carries on his treatment month after month will claim it as his achievement, but it would occur equally without his aid. From its nature, however, as already stated, it may probably be always augmented by some contrivance to increase the influences that are really improving the power of the muscles. Subacute and Chronic Ateophic Spinal Paralysis (subaotite and cheonio polio-myelitis). Under this designation cases have been described of a miscellaneous character, in which paralysis, followed by muscular atrophy, comes on less rapidly than in the acute form, its development occupying from ten to thirty days in the cases which are termed " subacute," and from one to six months or even more in those which are called *• chronic." Many cases included under this name differ much in their characters, and are sometimes described as ** chronic myelitis ; " but among the cases placed, even untU lately, in this group, are forms of multiple neuritis. Most subacute atrophic palsies are due to nerve disease ; almost all, indeed, which present symmetrical palsy. The cases of spinal atrophic paralysis, in which the onset is not acute, may be placed in four classes. ACUTE ATROPHIC PARALYSIS. 425 (1) Cases of subacute polio-myelitis wliicli differ from tlie acute form, already described, only in their less rapid development. They present the same initial general disturbance and wide distribution, and the same recovery, except in a limited region in which muscular wasting occurs. They are thus distinguished from polyneuritis, and also by the irregular distribution of the symptoms. Most of the suf- ferers have been adults. Little is known of the exciting cause of this form further than that it certainly sometimes follows exposure to cold, and is probably sometimes the result of a toxsemic influence. The symptoms and general history of these cases present no important difference from the acute form. (2) Cases are met with that differ from the type just described in the fact that their course is progressive. The onset is subacute or sub- chronic, occupying from a fortnight to several months, but instead of arrest followed by improvement, the more or less rapid onset is fol- lowed by slower gradual increase, until at last wide-spread chronic muscular atrophy is developed. Many of these are really cases of progressive muscular atrophy with a subacute onset. For example, I have more than once known a case of this disease, ultimately typical, to begin by a subacute atrophic paralysis of the extensors of the wrists. These cases will be considered in the account of that disease. Others present differences from that malady and symptoms of more irregular character, which show that the lesions are distributed through various structures in the cord, and these must be regarded as cases of chronic myelitis involving the anterior cornua. This form also is chiefly confined to adults. It occasionally results from cold, and sometimes from injury, as a fall on the back. Intemperance and venereal excesses are also said to cause it. The wide-spread muscular atrophy which sometimes results from lead-poisoning is probably of this nature. The muscles at first present the degenerative reaction, or normal faradic irritability with increase to volfcaism; sometimes, however, there is a loss to both f aradism and voltaism. The sphincters usually escape. In many cases the affection exhibits a persistently progressive character; muscular atrophy slowly increases and ex- tends, until the case ultimately resembles one of progressive muscular atrophy, and the patient dies at the end of one or two years from exhaustion, or from interference with the respiratory movements. In other cases the atrophy, after slowly progressing for many months, becomes stationary, and considerable improvement may ultimately take place. This course is seen especially in traumatic cases. Few- observations on the pathological anatomy of the affection have been made. Cornil and Lepine found, in one case, at the end of four years, softening of the lower part of the spinal cord, chiefly in the anterior cornua, disappearance of the ganglion-cells, increase of the connective tissue, and sclerosis of the white substance around the anterior horns. The diagnosis from the first form rests on the slow onset and pro- 426 SPINAL COED. gressive course of tlie disease. Althougli the degenerative electrical reaction may be found, it is frequently absent, and this is another distinction from the acute variety. On the other hand, the fact that paralysis precedes wasting is a distinction from progressive muscular atrophy. In the most chronic form, however, this distinction fails, and cases are met with which present a gradation between the two diseases. The prognosis is grave except in traumatic cases, but is influenced by the observed rate of progress, and the presence or absence of any indications of arrest. When the result of injury, considerable im- provement is not uncommon, and it is remarkable how great a degree of paralysis and atrophy may, in these cases, ultimately pass away almost completely. The treatment of the disease must be influenced by the rapidity of its onset. In the subacute stage and form it should be conducted on the same principles as that of acute cornual myelitis. In the chronic form the treatment must be the same as for progressive muscula-r atrophy. (3) Many subacute and chronic cases, which have been described as atrophic spinal paralysis, are peripheral, not central in their nature, and are cases of multiple neuritis, the symptoms and diagnostic indications of which have been already described. The history of the subacute spinal disease has been largely written from cases of multiple neuritis. In the statements just made this fact has been kept in view. While multiple neuritis may simulate closely chronic polio- myelitis, it is certain that the converse is also true, and the central affection has been sometimes thought to be peripheral. The facts at present available suggest that the central and peripheral structures of common function possess common susceptibilities to the action of morbid influences, and there is still danger that the two classes may be confused. The most important criterion is the greater irregularity in distribution of the central disease, — the more perfect symmetry of the peripheral affection. The presence of tenderness of the nerve- trunks, and of the structures to which the nerves are distributed, is of more value, when it exists, than is the suggestion afforded by its absence that the disease is central, because, in the periphery, only fibres of one function may suffer : we may then have none of the symptoms that we commonly associate with neuritis, and look for as proof of its existence. In pui'ely motor neuritis there may be no tenderness or pain. But such an affection is either unilateral or perfectly symmetrical. Imperfect symmetry indicates an affection of the cord. (4) A family form of slow muscular atrophy in children with changes in the anterior horn ceUs has been described in the last few yeais by Hoffmann and others. It will be referred to when we come to speak c f the myopathic atrophies with which it has some affinities. ACUTE ASCENDING PARALYSIS. 427 ACUTE ASCENDING PARALYSIS. Ascending paralysis, which commences in the legs and ascends to the muscles of the trunk, the arms, muscles of the neck, the diaphragm and the pharynx, is a feature of several diseases — meningeal hsenior- rhage, ascending myelitis, &c. ; but it occurs also in cases in which the spinal cord, after death, appears healthy to both naked-eye and microscopical examination. Such cases have, however, certain charac- teristic features which make it desirable to distinguish the condition from other diseases, and the affection has, therefore, been provisionally termed ''acute ascending paralysis," in the absence of any evidence of its nature. It was first described by Landry in 1859, and hence is often called Landry's paralysis. Acute ascending paralysis is a most formidable malady, most cases proving fatal in a few days. Its nature is mysterious, but recent discoveries regarding midtiple neuritis have disclosed instructive analogies between the two affec- tions. These have, indeed, led some observers to the opinion that this ascending paralysis, without organic central lesion, is an affection of the nerves.* As we shall see, it is not probable that this opinion is correct, although it is possible that the nerves, as well as the centres, are sometimes affected. Causes. — The etiology of the disease resembles, in general, that of acute multiple neuritis more nearly than that of any other affection. The disease affects males more frequently than females. It occurs chiefly between twenty and forty years of age, but has been observed in rare cases in older and younger persons, and even in children. Some sufferers have been the subjects of alcoholism. Severe exposure to cold has been the apparent cause in many instances. In other cases the disease has occurred under conditions such as cause toxsemic states, or after the occurrence of some known blood disease. Thus it has occurred during convalescence from some general disease, smallpox, diphtheria, typhoid fever. It has also followed influenza and febrile diseases of obscure nature. In these cases, it should be noted, the disease has followed at an interval of a week or a few weeks. It also soBietiiiies succeeds some traumatic process, such as a wound, and here also after an interval, and usually when the wound was apparently healed. I have known it thus to follow an attack of pelvic cellulitis. In these respects it closely resembles polyneuritis ; and it has been observed, in severe form, in the subjects of old alcoholic neuritis. The disease has been repeatedly observed in the subjects of syphilis, and has apparently been arrested by the treatment for this disease, t The circumstance that when some malady or woimd pre- * See Eoss and Judson Bury, 'Treatise on Peripheral Neuritis.' t Much weight should not be placed on this fact as proof of causal relationship, because (apart from the fallacy of independent cessation) it is probable that the treatment that is effective against the virus of syphilis is also effective against other blood-states that depend on agents of similar nature. 428 SPINAL COED. ceded tte disease, tlie former was often of a trivial character, prevents surprise at the fact that, in many cases, no influence could be traced to which the disease could be ascribed. Symptoms. — Premonitory symptoms have been noted in some cases ■ — general malaise, pains in the head and back, tingling in the extremi- ties — for a few days or a week before the onset. The first definite symptom is usually weakness of the legs, often commencing in one and spreading to the other. The weakness increases rapidly, so that the power of standing is lost, sometimes in a few hoTirs, sometimes at the end of two or three days ; it goes on to complete paralysis, with relaxation of the muscles. As the legs become motionless the muscles of the trunk become weak, first of the pelvis, loins, and abdomen then of the thorax. The weakness next invades the arms ; either the upper arm muscles or those of the forearm and hand may be first attacked, and one arm is often weakened before the other. The paralysis of the arms may become absolute, like that of the legs, or some power of movement may remain. The diaphragm and neck muscles then suffer, and difficulty of swallowing comes on, sometimes wilh paralysis of the muscles of the palate, and often speech becomes difficult, nasal, and indistinct. The inability to swallow may become so great that the patient has to be fed through a tube, and the para- lysis may involve the muscles of articulation to such an extent that utterance may be altogether unintelligible. There is often dyspnoea from the weakness of the muscles of respiration, or from interference with the respiratory centre in the medulla, and the cardiac centre may also be involved. The affection of the bulbar nerves is determined by functional relations ; thus the lips may be paralysed with other muscles of articulation when the upper part of the face is unaffected. In rare cases the eye muscles are paralysed in some degree, usually manifested only as loss of accommodation, inequality or dilatation of the pupils, impaired reaction to light, or slight strabismus. The tinghng and analogous subjective sensory disturbance has been followed, in some cases, by hyperaesthesia of the skin and tenderness of the muscles, but it is probable that in such cases there has been multiple neuritis. There may be some blunting of sensibility in the extremities, but there is definite loss of sensation only in some severe cases of the typical disease. A firm touch can usually be per- ceived anywhere ; perception of painful impressions and of heat or cold is sometimes delayed. At first, reflex action is lost in the affected limbs, both cutaneous reflex action and myotatic irritability. In cases rapidly fatal the loss has continued tiU death. In cases that have recovered reflex action has returned, but recorded cases have presented considerable differences in this respect, and, as there is some doubt as to the nature of many non-fatal cases, there is some uncertainty as to this point. In some the myotatic irritability has soon returned, and has even become excessive. In the majority it has remained absent. ACUTE ASCENDING PAEALYSIS. 429 and not until all paralytic symptoms have disappeared has the knee- jerk returned. In spite of the early flaccidity of the muscles, if life is prolonged they rarely present either wasting or change in electrical irritabihty. A trifling reduction in size may occur, but there is no muscular atrophy such as occurs in polio-myelitis, and even after several weeks the most careful examination fails to reveal any abnormal electrical reaction — a very important feature of the disease. Exceptional cases, which do present the degenerative reaction in the muscles, seem more closely allied to a universal polio-myelitis, from which, indeed, this disease cannot be sharply separated. The sphincters, moreover, escape in the vast majority of cases, but not in all. There is no tendency to the occurrence of bedsores. The cerebral fiinctions are not usually involved, and the state of the patient who, with unimpaired intellect, cannot express himself either by speech or gesture, is painful in the extreme. In exceptional cases, however, there is mental dulness or slight delirium, as if from the influence of a blood- state on the brain. In girls this may take the form of hysterical manifestations, by which the nature of the disease may be masked. As a rule there is no elevation of temperature, even during the rapid development of the symptoms, but in one or two cases, which were not fatal, brief pyrexia attended the onset, and in a few others moderate febrile disturbance (2° or 3°) occurred at a late period. Profuse sweating has been occasionally noted. Enlargement of the spleen (first noted by Westphal), such as occurs in other acute diseases, ia very frequent. Thus the chief feature of the disease is an almost purely motor paralysis, progressive in character, with relaxation of the muscles during the acute stage of the disease. It usually has an ascending course, but irregular cases are met with in which the order of invasion is varied. Thus the arms are occasionally involved before the legs, the diaphragm before the intercostals ; the bulbar symptoms have been known to precede the others, and I have seen them reach a high degree with a fatal involvement of the cardiac centre before the upper muscles of respiration were affected, or the hands quite powerless. Analogous cases have been recorded by others, the special features and course being those characteristic of the disease. In some cases, however, of irregular course, changes have been found in the electric irritability of the muscles ; it is probable that, in such cases, the peri- pheral nerves are affected, although we cannot, on this account, at pi-esent separate these from the typical cases of the disorder — a point that will be explained in connection with its pathology. The disease varies considerably in the rate of its progress. It may run its course and end fatally in forty-eight hours. Death usually results from either respiratory or cardiac paralysis — the latter in the cases of irregular course. A large proportion of the fatal cases last less than a week. On the other hand, the disease may only attain its 430 SPINAL COED. lieiglit at the end of two, three, or even four weeks. In some cases, apparently of the same character, the paralysis of the limbs has not been complete. There may be a rapid extension of the paralysis to a certain point, and it may then cease to spread, and the limbs last and least affected may slowly regain power. A patient may lie for days in a condition of universal palsy, save for a little respiratory power, and then improvement begin. As a rule, the order of recovery of the muscles is the opposite to that of their invasion. In favourable cases the recovery of power is usually slow; two or three months often elapse before the weakness entirely disappears. Occasionally there has been a more rapid improvement, and the patient has been well in a few weeks. Pathologt. — The most careful and skilled examination has often failed to discover any morbid appearance in the spinal cord, nerves, or muscles. Minute hsemorrhages, met with occasionally, have probably occurred during the last moments of life. In other cases, apparently similar to the others, vascular engoragement has been found in the grey matter of the cord, the significance of which is increased by leucocytal accumulations around the vessel. Changes in the ganglion-cells in the more acute cases have also been found, swelling and blurred outline.* Of late attention has been paid to the peripheral nerves and sHght indications of acute changes, both parenchymatous and interstitial,t have been found in them, but only in exceptional cases, and peripheral neuritis seems to play no part in the typical disease, although sometimes simulating it. In addition to the enlargement of the spleen observed during life, and found also after death, the mesen- teric glands have been found swollen, and also the closed follicles of the intestines. Organisms have been found in the glands,J and culture of portions of the nerve-centres yielded, in one case, a bacillus resembling, but not identical with, that of splenic fever. § Other observers have searched for them without success in all cases of typical character. These negative facts, taken in conjunction with the conditions under which the disease occurs, and with the course of the malady, have suggested the idea of a toxic influence acting on the nerve-centres ; and this idea receives support from the discovery that acute swelling of the spleen is common, and of the lymphatic glands not rare — lesions that indicate a morbid blood-state. The limitation by func- tion of many toxsemic palsies, e. g. that of accommodation, supports this view, since the isolated acute paralysis of functional centres, not anatomically separate from others, is known only as a consequence of a toxic influence. Further confirmation is afforded by the fact that cases of acute multiple neuritis, certainly due to a toxaemia, may run a * Immermann, Marinesco and Marie, Bailey and Ewing, t Eisenlohr, • Deut. med. Wocbenschr.,' 1890, No. 38. X Baumgaiten. § Marie and Marinesco. ACUTE ASCENDING PARALYSIS. 431 similar course. It lias, indeed, been conjectured that the neryes are always the structures impaired, but this exclusive view is disproved by the normal state of the nerves in cases in which the grey substance of the spinal cord has been found to be changed and by the common absence of altered excitability of the muscles, since the motor nerves seem never to escape invariably in peripheral neuritis of any variety, however common their freedom from affection in the type. But the nerves suffer also in some cases, and there seem to be gradations to the cases of acnte multiple neuritis of ascending course described at p. 162. All the facts point to the conclusion that the disease is due to a toxin which has a specific action on the motor neurons in the spinal cord, chiefly on the anterior gi'ey matter, sometimes also affecting the motor nerve-fibres proceeding from them. Sometimes it has a wider influence on the spinal cord, and its effects can be traced into the white substance or the posterior horns, possibly as an extension of the inflammatory changes it induced. These are similar to those that attend any acute disturbance of function; the toxic influence is mysterious in nature and origin, but seems to resemble that which causes polio-myelitis, in which the morbid process presents variations and may also involve the nerves. The toxine may be pro- duced by the agency of bacteria, but the evidence of this is incon- clusive ; some cases have followed exposure to cold. DiAaNosis. — The disease is recognised by the rapid development of paralysis, usually but not invariably ascending, with relaxation of the muscles, and with loss of reflex action, without considerable pain or, generally, any loss of sensation, and if the patient survives, without wasting of the muscles or change in electrical irritability. The latter characteristic distinguishes the disease from acut« atrophic paralysis, while the absence of pain in the back and of spasm is a distinction from meningeal hsemorrhage. The diagnosis from general ascending myelitis has been already considered; it rests especially on the in- volvement of all the functions of the cord in inflammation. The distinction from multiple neuritis has been mentioned in the account of that disease (p. 174), but, it may be, is not always absolute, since the nerves probably suffer, as well as the cord, in some cases of ascending paralysis. Further, the cases of multiple neuritis simulating this affection, the nature of which has been demonstrated pathologi- cally, have usually run a more prolonged course, several weeks or even months. The distinction from polyneuritis, founded on the course of the ascending form, is subject, however, to the reservation that while ascension to the arm through the trunk is a feature of the central disease, this is not excluded by a more irregular course, and the character of the individual symptoms must be taken into consideration (see also p. 429). Pkoqnosis. — The affection is one of extreme gravity. The danger to life is in. proportion to the interference with respiration and with the functions of the medulla oblongata, especially with the cardiac 432 SPINAL CORD. centre, and also to tlie rapidity with TvTiicli tlie palsy comes on. But the cases which develop with comparative slowness are not devoid of danger. Even when the symptoms only reach their height at the end of three or four weeks, death may occur in the same way as in the more rapid cases. On the other hand, recovery has been known although the patient has lost all power of motion at the end of the second day. The danger is great as long as the symptoms are in- creasing, and only when distinct improvement can he recognised is it justifialble to anticipate recovery. The earlier the bulbar symptoms appear, the more serious is their significance. Mental symptoms also increase the gravity of the prognosis, as they usually indicate a severe blood-change, the effects of which on the nervous system are likely to reach a high degree. Treatment. — During the early stage of an attack of acute ascend- ing paralysis, in the absence of other indications, the treatment should be that suitable for myelitis, since, at the onset, the diagnosis between the two diseases can never be certain. A warm bath, or still better, a vapour bath, should be given if the symptoms followed exposure to cold. It should be followed by counter-irritation over the spine by a long, narrow mustard plaster. More energetic counter-irritation, even the actual cautery, has been recommended. The body should be kept in as perfect rest as possible, and on the side rather than on the back. In very few cases have drugs appeared to exert any influence on the course of the disease, and the malady is so rare that experience accu- mulates slowly. Salicylate of soda seems to deserve a trial in cases that follow exposure to cold. Ergotin has been given, and one case in which it was used deserves special mention. The patient was a man aged fifty-seven, who, a week after exposure to cold and wet, com- plained of a feeling of weight and weakness in the legs ; the temperature rose to 103° ; the loss of power gradually became complete in the legs and spread to the arms, without loss of sensation. At the end of the second day there was difl5.culty in swallowing, in articulation, and in breathing, and death seemed near. Ergotin was given every hour, and during the night the patient took twenty grains. In the morning the bidbar symptoms were better, the arms stronger, and there was a trace of motoi' power in the legs. The patient rapidly improved, and at the end of a week was well. If swallowing becomes difficult, care must be taken to administer a sufficient amount of nourishment, either by the reotum or by the nasal tube. A few cases have been recorded in persons who had had syphilis, in whom arrest of the disease followed the administration of iodide of mercury. The chief lesson of modem research is certainly that we must look for the means of effective treatment to the neutralisation of the toxic influence on which the malady apparently depends, but at present nothing has been ascertained regarding antidotal agents available in the acutely active stage of these toxsemic states. It is, however, pro- bable that mercury is capable of doing good, and that when the causa- DIVERS* PARALYSIS. 433 tion IB o'bscure, and tlie disease develops slowly enougli to permit mercttrial treatment, it is "wise to adopt this irrespective of the fact of preceding syphilis. In cases that follow traumatic lesions, especially if there have been any indications of septicsemia, full doses of per- chloride of iron offer, I believe, the best means of destroying the activity of the blood-state. The general and local treatment should be the same as in acute myelitis. PAEALTSIS FROM LESSENED ATMOSPHETMC PRES- SURE; DIYERS' PARALYSIS; CAISSON DISEASE. Divers, and especially those who work in caissons, at such a depth beneath water that they are exposed to considerable pressure, may be- come paralysed soon after their return to the surface.* Apoplectic attacks and hemiplegia also sometimes occur, sometimes transient mental disturbance, or deafness, or bleeding from the nose, but para- lysis of the legs is by far the most common effect, and it is, therefore, clear that the spinal cord suffers in greater degree than any other part of the nervous system. Miners have been said to suffer also, but this is doabtful, because a pressure equal to at least an additional atmosphere seems necessary for the production of the symptoms. Most of the subjects of the disease have worked at a depth of from forty to ninety feet below the surface of water, and under a pressure of two to four atmospheres. In the extensive works involved in laying the foundations of bridges, in which many men have been employed, a considerable proportion of the workers have suffered in some measure ; but severe degrees of affection are rare, because the conditions under which they occur can be avoided. They only occui- in those who have been exposed for more than a certain time, which is the shorter the greater the pressure. At a depth of ninety feet beneath the surface immtmity from severe symptoms (and commonly from all symptoms) is obtained by reducing the periods of work to an hour. The danger ,is greater in those who have had several previous periods of work on the same day, and especially if slight symptoms have been experienced after one of these. It is also greater in those unaccustomed to the conditions. I have met with one case of hemiplegia in a diver after only half an hour's work in a well at ninety- six feet, but the man had been down twice before with only intervals of rest of half an hour, and the attack passed off in the course of an hour. In another case paraplegia occurred after working for an hour under only fifty feet of * See, on this subject, Babington and Cuthbert, ' Dubl, Quart. Journ.,' 1863, p. 312 (cases at Londonderi-y) ; Eads, 'Med. Times and Gaz.,' 1871, p. 291 (cases- at St. Louis) ; Leyden, * Arch. f. Psychiatrie,' ix. Heft 2 j and Moxon, ' Lancet,* 1881, ii, 529. VOL. I. 28 434 SPINAL CORD. water, but tlie man liad worked on tlie preceding day at a depth of one hundred and twenty feet below the surface. It is evident, there- fore, that the power of resisting the dangerous injEuence varies, and that predisposition to suffer may be caused by the conditions which also induce an attack. It is not during exposure to the abnormal conditions, but on return- ing to the normal atmospheric pressure, that the symptoms come on ; often immediately, and always within half an hour or at most an hour of the return to the surface. The onset is usually preceded by other symptoms, and especially by pains in the ears and in the joints. The latter are very common, and occur after a much slighter degree of exposure than is needed to produce paralysis. They are felt chiefly in the larger joints, and may continue for days and even longer. Yery rarely there is also swelling of the joints. The deafness occasionally observed has been usually bilateral, often persisting in one ear, but passing away in the other. It has even been attended by severe vertigo. The severer degree has been ascribed to haemorrhage into the labyrinth, but no pathological facts are at present available. It is important to note the conditions under which the symptoms come on. ISTot only do those who are unused to such work seem especially liable to suffer, but there are also considerable individual variations in the degree of liability. Paraplegia or hemiplegia may occur, but the former is far more common. The onset of the paralysis is sudden. The legs feel heavy and are found to be weak, and in a few minutes the patient is unable to move them. Sensation is often lost as well as motion, and ia all severe cases the sphincters are affected. The arms are seldom involved. In sHght cases the loss of power is incomplete, and one leg may be more affected than the other. The impairment of sensa- tion is often imperfect or irregular. If the paralysis is incomplete the power may return in the course of a few days, but in severe cases the palsy usually lasts for weeks or even months, and it may be permanent. Death may occur at the end of a week or more, in the same way and from the same causes as in acute myelitis. When the paralysis is hemiplegic it is generally moderate in severity and transient, passing off in a few hours or days. It may be even still more brief, as in the case referred to above, in which a diver, after half an hour's work ninety-six feet below the surface, suddenly felt tingling across his loins, and that his right arm and leg were almost powerless ; in half an hour he had recovered sufficiently to walk home- If cerebral symptoms are more intense, they are generally very severe. with sudden loss of conscioTisness, continuing as deep coma, irregulai I)reathing, and indications of cardiac pavT lysis. Such cases Tisually «nd in death in the course of a few hours. Pathology. — The most probable explanation of these cases ascribes them to the escape from the blood of gases, with which it has become divers' paralysis. 435 charged during the exposure to the high pressure. It is certain that a great excess of gas must be dissolved in the blood during the expo- sure, and that the amount, at least of oxygen and of carbonic acid, contained in the blood when the person emerges from the caisson must be vastly greater than normal. It must, moreover, be greater the longer the exposure, since the absorption of the excess vsdll be a gradual process, taking place through the lungs in respiration, but it will be more rapid as the pressure is greater. These conditions agree with observed facts. After returning to the normal atmospheric pressure, the excess of gas probably passes off gradually by the lungs in most instances ; but if extreme, gas may escape from the blood within the body. The occurrence of this has been proved experimen- tally (Hoppe-Seyler and P. Bert). G-as, so escaping, is no doubt quickly reabsorbed, but must exert a pressure capable of arresting the function of the structures of the nervous system. If abundant, it may conceivably rupture these. Further, the special effect on the nerve-centres may be connected with the position of these within cavities that are practically closed. These conditions, coupled with the extremely circuitous course of the blood from the cord, may explain the incidence of the effects on the nervous system. The few ascertained facts harmonise with this pathology. Such escape of gas has been proved to result from diminution of the atmospheric pressure.* In many cases no visible lesions have been found, and it is obvious that gas, widely effused, may exert dangerous pressure, and yet may be speedily removed, so that no indication may remain of the cause that has completely arrested function. It was once thought that the symptoms were due to local haemor- rhages, but extravasations are seldom met with, even in the results of experiment, and it is certain that they take but a trifling part in the production of symptoms. The only positive pathological observation agrees with the opinions above stated. Ley den f foimd (in a case of characteristic paraplegia) small irregular fissures in the mid-dorsal region, chiefly within the posterior and hinder parts of the lateral column. The fissures were filled with round-cells, but contained no red blood-corpuscles, and from their well-defined edges they were cer- tainly not produced by the infiltration of the cells found within them. The only explanation that is satisfactory, or in any harmony with their features, is that they were produced by the sudden escape of gas, and were afterwards occupied by the round-cells. | The physical firmness of the cord is far less in the dorsal region than in the en- largements ; and probably, as Ley den suggests, this is the reason why the dorsal region suffers structural damage from the escape of gas * Hoppe-Seyler, 'MuUer's Archiv,' 1887; P. Bert, 'Comptes Rend.,' 1871-2. t • Arch. f. Psych.,' ix. Heft 2. J The clinical condition of transient hemiplegia, which has been observed in empyema as occurring during irrigation, and thought by some to be the result of air or gas embolism, may be of similar nature. 436 SPINAL COED. more than otlier parts. It is evident, however, that such escape maj occur in the brain, for instance, even to a fatal degree, and leave no traces unless it occurs so rapidly as to cause laceration of the tissue. The absence of haemorrhage of the ordinary chara.cter may be further explained by the fact that the effused air will resist the effusion of blood. Some other anomalous features, such as the transient cha- racter of the symptoms in some cases, are also explained by the peculiar nature of the lesion, which may exert a wide-spread and considerable influence, and in a short time may have vanished by the reabsorp- tion of the compressing air. Haemorrhage must be regarded as an accidental consequence, and the production of such fissures as were found by Leyden may not be a necessary part of the lesion, even in grave cases The mechanical effects of the gas may be considerable, and arrest the function of the nerve-elements, without the passage of the gas outside the capillary vessels. The fact that the spinal cord suffers more than other organs may be partly due to the plexuses through which the blood can return only slowly to the lungs, where its relief from the surcharge of gas is effected. The same considerations apply to the brain. In both organs the escape of air is more instantly disastrous than elsewhere, and, indeed, may not only occur, but act in a peculiar way, on account of the posi- tion of the organs within chambers that are, to a large degree, closed. The conditions are too complex to permit us to follow them in detail, or analyse fully the mechanisms that determine the effect on the nerve-centres. The escape of the excess of gas in the lungs can only take place gradually, as successive quantities of the surcharged blood pass through the capillaries of the air-cells. If, in consequence of the slowness of the circulation in the cord, any escape of air occurs in its capillaries, the effect of this will be still further to hinder the local circulation, and to favour the further escape of gas. In this way we are able to discern something of the mechanism which determines the special affection of the spinal cord. The less the external support the less will be the resistance to the escape of gas, and the incidence of the lesion on the posterior part of the cord may be, in part at least, determined by the adoption of the recumbent posture when the first symptoms are perceived. At the onset, when the first symptoms are experienced, it is probable that a return to a greater degree of pressure might arrest the develop- ment of the mischief. It is certain that, in all cases of exposure to a high degree of pressure, the transition to the normal pressure should be made gradually. When developed symptoms indicate that a definite lesion of the cord has occurred, the further treatment must be conducted on the same principles as in acute myelitis — the morbid process that has, in fact, been set up. H^MOEEHAGE. 487 H^MOERHAGE INTO THE SPINAL CORD; H^MATOMYELIA. Primary hsemorrliage into the spinal cord, sufficient to cause sym- ptoms, is a very rare disease, and it is even more rare than is suggested by the cases now and then recorded as such. We have ah-eady seen that haemorrhage may accompany myelitis ; a considerable extravasa- tion may occur when the inflammation is only commencing, during the state of congestion, and while the symptoms are slight. Such cases are easily mistaken for primary haemorrhage. The risk of error is not always removed by pathological examination. Inflammation results from haemorrhage, and when indications of myelitis are found about a clot, it may be impossible to say whether these are primary or secondary. It is probable that many cases of secondary myelitic haemorrhage have been regarded and described as primary, and it is possible that a few cases of primary haemorrhage have been regarded as secondary. One writer, Hayem,* goes so far as to deny the occur- rence of primary non-traumatic haemorrhage ; but such an exclusive view is unwarranted. It is certain, however, that the history of primary haemorrhage has been largely written from uncertain data, and will need extensive revision when a sufficient number of exact observations have accumulated. It is probable that the causal influences constitute the surest guide. When haemorrhage occurs under conditions which usually induce myelitis, the extravasation must be regarded as the result of the vascular disturbance of com- mencing inflammation. Etiologt. — The rarity of haemorrhage into the cord is especially great in comparison with the frequency of haemorrhage into the brain. The difference probal^ly depends on the tortuous and long course of the arterial path to the cord, whereby the vessels are preserved from the high pressure which is the chief cause of the degeneration, dilata- tion, and rupture of the cerebral arteries. Miliary aneurisms are not found within the spinal cord. Haemorrhage is far more common in males than in females. It may occur at any age, and has been met with in young children, even so early as seven months,t while some of the subjects have been in advanced life ; but it is most common between twenty and forty, i. e. during the first half of adult life. Many cases occur in young adults apart from injury or obvious exciting cause, and apart also from initial myelitis, which accounts, however, for some of the cases. It has been met with as a conse- quence of a haemorrhagic tendency, as in a case in which it succeeded * ' Des H^morragies intra-rachidienues/ Paris, 1872. + Clifford Allbutt, ' Lancet,' 1870, vol. ii, p. 84. Numerous haemorrhages were observed in the grey matter of the lumbar and cervical enlargements (probably polio-myelitic, but occurring the day after a fall) in a child of four by ChafEey (' Path. Trans.,' 1885). 438 SPINAL CORD. severe epistaxis, to whicli the patient, a young man of twenty- four, was liable.* Of immediate causes, injury is the most frequent, especially falls whicli involve a severe concussion of the spine ; the spinal column may or may not be injured at the same time. Over-exertion and exposure to cold have in rare cases preceded the onset. Chronic alcoholism and sexual excess have been thought to predispose. In one case within my knowledge, an extensive hsemorrhage into the grey substance ai the top of the lumbar enlargement resulted from coitus four times repeated, the symptoms commencing suddenly during the fourth act. Minute extra,vasations are often found after death from diseases which interfere with respiration and cause venous congestion, and they are especially frequent in maladies which at the same time cause func- tional excitement of the cord, as tetanus and all severe convulsions. They cause no symptoms, and are probably produced during the last moments of life. They have been termed " accessory." The diseases of the cord that lead to secondary hsemorrhage are chiefly inflamma- tion, tumours, and cavities in the cord. The last-named condition is especially important. It is probable that hsemorrhage occurs more readily if the spinal cord contains a congenital cavity or fissure, due to an arrest of development, and surrounded by embryonal neuroglial tissue. Hence this condition will be fotmd in disproportionate fre- quency in cases of hsemorrhage. PATHOLOGICA.L Anatomy. — The minute extravasations just men- tioned, as met with after asphyxial and convulsive diseases, are found in both the grey and white substance, but especially in the former. They are usually microscopic, or visible to the naked eye as minute red points, distinguishable from distended vessels only by their slighter resistance to a stream of water. The extravasation may occupy the perivascular sheath, or the cavity in which the vessel lies, or extend between the nerve-elements. The larger non-traumatic haemorrhages, which cause symptoms, always begin in the grey substance, and are often confined to it, extending into the white columns only when large in size. The vessels of the grey substance are more numerous than those of the white, have less external support, and probably undergo more considerable changes in state. The effusion forms a cavity in the cord, sometimes rounded, sometimes irregular in transverse section, and half an inch or more in vertical extent. The cord is enlarged at the seat of the hsemorrhage, and this may be visible externally as a dark swelling the size of a nut or a bean. Very rarely the hsemorrhage tears the layer of cord which limits it, and blood, usually only in small quantity, escapes into the membranes. The tissue adjacent to the clot is usually broken down, stained, and softened, and inflammatory changes may be recognised in it with the microscope, just as in the neighbourhood of hsemor- rhages into the brain. As in the latter, the effused blood slowly * Sinclair, ' Lancet/ 1885, ii, p. 1043. h^moeehagb. 439 undergoes changes in tint, becoming first rusty and then 3'ellow, and ultimately a cyst may remain. Several extravasations may co-exist, usually in the same part of the cord. In contrast to this focal Jisemorrhage there may be an infi.ltration of the grey matter with punctiform extravasations, which may appear, until closely examined, to be a single haemorrhage. The tissue bet"ween these small extra- vasations is broken down. It is probable that this form is always secondary to myelitis, as in the case mentioned in the foot-note on p. 437. In such secondary cases a careful microscopical examination usually reveals indications of inflammation much more extensive than the area affected by the haemorrhage. A growth into which hsemor- rhage occurs is usually a glioma, unaffected parts of which will be found in the neighbourhood of the extravasation. The cavities in the cord into which blood may escape are sometimes of considerable vertical extent. I have known a fissure in the posterior column to be filled with blood through almost the whole length of the cord. This condition thus favours both the occurrence and the extension of haemorrhage. Symptoms. — Slight symptoms, " prodromata," have been obseiwed in some cases, chiefly in the form of trifling sensory disturbance, tingling, &c., in the Hmbs afterwards paralysed. They have existed for a few hours or days, or even for two or three weeks before the onset. It is probable, however, that these have been cases of secondary myelitic haemorrhage, and that there are no premonitory symptoms in primary extravasations. The actual onset is always sudden ; the symptoms attain a considerable degree in the course of a few minutes, but they sometimes increase during one or two hours, when the haemorrhage is from a small vessel and slowly increases in size — probably augmented by the rupture of other vessels which are torn in the tissue lacerated by the blood. Occasionally there has been transient loss of consciousness without any cerebral lesion, probably from the upward influence of the shock. Earely the onset has been by a series of sudden augmentations of the symptoms. Sometimes the symptoms come on during sleep. The suddenness of the onset is the characteristic of the disease. The symptoms which thus develop vary according to the seat and extent of the extravasation. In the majority of cases there is para- plegia, coiuplete motor and sensory paralysis up to the level of the lesion, with loss of power over the sphincters. Pain commonly but not invariably accompanies the sudden palsy ; it may be felt in the spine or in the sacrum, round the trunk, at the front of the thorax, or at the epigastrium, sometimes seeming to pass thence through the trunk to the spine, or it may be felt in the legs. If in the spine it is local, and does not extend through a considerable length of the spine, as in meningeal haemorrhage, and there is not the initial spasm and rigidity which characterise the latter disease. This pain may precede the palsy, even for half an hour or an hour ; it begins suddenly, 440 SPINAL CORD. and is n(> doubt due to tlie first sliglii; extravasation, whicli afterwards increases (when some resistance yields), and effects the compression tliat produces the paralysis. Thus a girl aged fifteen was seized with sudden sharp pain, referred to the sternum at the mammary level, and to the corresponding region of the spine ; this continued for half an hour, when the legs suddenly became powerless and insen- sitive. It is highly probable that when there is such initial medial or bilateral pain the haemorrhage occurs in the central region of llie grey matter, perhaps from one of the commissui*al or anastomotic arteries (see p. 227), and that the pain is due to the irritation of the fibres of the posterior commissure, in which the paths for pain cross the middle line. The spinal column may be tender opposite the affected spot. TJsiially the paralysed muscles are relaxed. Some- times they are the seat of early clonic contractions, or these may come on a few days after the onset. When the hsemorrhage is in the cervical region all the limbs are powerless ; one arm is often affected before the other. The state of reflex action varies according to the seat of the disease ; if it is at first abolished it quickly returns in the legs (unless the hsemorrhage is in the lumbar enlargement), and it soon becomes excessive unless destroyed by secondary myehtis — a not unfrequent consequence. In one case there was a remarkable initial increase of myotatic irritability a few hours after the onset, probably irritative, and quickly giving place to loss.* Vaso-motor and trophic changes in the skin are common and often intense ; there is often vascular dilatation ; bedsores readily form, and cystitis may result. Frequently the secretion of sweat is increased for a time. The temperature is normal at the onset, but it generally rises in the course of a few days from secondary inflammation in the cord. The palsy developed at the onset usually continues for a week or ten days, although the pain may lessen. The symj^toms do not always increase during the stage of inflammation, perhaps because this only involves the structures which are already impaired by pressure ; but if the patient has been brought near to death by the primary haemor- rhage, the secondary inflammation may end hfe. Occasionally, more- over, symptoms of an ascending or descending myehtis may come on, and the former may cause death by its interference with the muscles of respiration. This extension is greatest probably in cases of myelitic hsemorrhage, in which the extravasation is merely an incident in the course of a commencing inflammation, but it seems also to occur in cases of primary hsemorrhage. The slow extension upwards of the symptoms during the first week may be very distinct ; and the occur- rence of descending inflammation may be shown by the loss of reflex action, and by the failure of electric irritability in the muscles, sometimes only in those supplied from the upper part of the lumbar enlargement. The symptoms pass into a chronic stage, improvement being usually slow. Some lasting loss of power remains in most cases, and there ia * Sinclair, loc, cit. H^MOERHAGE. 441 often some permanent muscular wasting on account of the frequency with whicli the haemorrhage is in the cervical or lumbar grey matter. Occasionally there is rapid recovery up to a certain point ; a haemor- rhage of small size may abolish conduction in the white columns by the suddenness with which it compresses them, and the effects of the pressure may quickly pass away, while those remain that are due to the destruction of the grey matter. DiACNOsis. — The diagnosis rests on the actually sudden onset of the symptoms, and on the occurrence of pain, in a limited region, as part of these. The former is evidence of a vascular. lesion (rupture or closure), and the latter shows an acute irritation of the nerve- elements, such as may be produced by their laceration, but not by mere deprivation of blood. It must be remembered, however, that we cannot assume that symptoms which come on during the night's sleep are of sudden onset. Neglect of this consideration sometimes causes a mistake in diagnosis. The mode of onset is a sufficient distinction from all other organic diseases, except haemorrhagic myelitis and meningeal haemorrhage. The former (really a variety of haemorrhage) is distinguished by the existence of slight symptoms before the sudden attack. We are not justified in regarding as primary haemorrhage any case in which premonitory symptoms existed for more than a few minutes, unless such symptoms were so pronounced and sudden in onset that they might have been due to a definite extravasation, afterwards increasing. Initial fever (within the first six hours) always makes myehtis probable, provided there is no other cause for it. The distinction from meningeal haemorrhage has been mentioned in the account of the symptoms, and in the description of that disease. Prognosis. — In all cases in which the symptoms are considerable in degree or wide ia range, the danger to life is great, and remains great until they begin to subside. The prognosis is better when the disease is in the dorsal region than when it is in the enlargements, for the same causes as influence the prognosis ia myelitis. It is better when sensation retiims in the course of a few days, but if the enlargements are affected other sources of danger remain considerable. Early trophic changes also render the prognosis worse, for they show an intensity of degree that may involve grave danger. After the onset is over, the forecast must be guided by the general principles that deter- mine the prognosis in acute myehtis. Treatment. — The treatment of haemorrhage into the subst-ance of the cord is the same as that of haemorrhage into the membranes (p. 339) The measures requisite are few, simple, and all-important. Absolute rest and the prone position are to be secured bef oi-e anything else is thought of. Ice should be applied to the spine over the seat of the haemorrhage. The bowels should be opened freely, and fidl doses of ergot or ergotin may be given : 5ss of the liquid extract or five grains of ergotin may be given by the mouth, or three grains of ergotin 442 SPINAL COED. may be injected iinder tlie stin, and tlie dose may be repeated two oi three times, at intervals of two hours. A few large doses are probably more effectual than smaller doses continued for a longer time, since tbe baemorrliage probably does not go on for long. The after-treat- ment must be that for myelitis. The disease is one of those in which most of the good that can be done by treatment — and in few diseases is the opportunity more urgent— rests with those in whose hands the patient is immediately after the onset. DEGENERATIONS OF THE SPINAL COED. A large and important class of diseases of the spinal cord consists of those in which there is a slow degeneration of the nerve-elements, with an overgrowth of connective tissue, and in which structures are affected that have a common function, while others that have a different function escape even when they are adjacent to the elements that are diseased. Affecting thus functional " systems," they are termed '• system diseases." This term has been used in several senses, more or less special (even based on the developmental relations of the structures), and hence the question whether a given malady is a " system disease " or not, is one to which various answers have been given. The term is here used in its widest and simplest sense, aa meaning an affection of the structures that have a function either the same, or so far allied that they work together as parts of one system, distinguishable as such from other sets of structures. A " system disease " may involve all the structures of the system, or only some or one of them ; its chief distinction is from a random disease that involves structures irrespective of function — merely, for instance, because they are contiguous, or supplied by the same artery. In " system diseases " the primary change is, as a rule, in the nerve-elements, and the overgrowth of interstitial tissue is secondary. The process is analogous to that which occurs in the secondary degeneration of nerve-fibres, in which the first change is certainly in the nerve-elements, the destruction of which is followed by an over- growth of nuclei and supporting tissue, amounting ultimately to a " sclerosis," as it is termed. The process is by some regarded as a chronic parenchymatous inflammation, an inflammation beginning in the proper functional elements of the organ, but it seems undesirable thus to widen and loosen our conception of inflammation ; so far as the process is concerned the question is one of name rather than of nature. Another question of much greater interest is the relation of the two elements in the process, the wasting and the growth, the atrophy of the DEGENERATION. 443 nerve tissue, the hypertroplij of tlie connective tissue. The failure of nutrition in the one causes an increased energy of nutrition in the other. We have seen this relation in the nerve-fibres. The degene- ration of a fibre is attended by an active growth of its nuclei and protoplasm. The nutrition of the two elements, the neural and the adventitial, is evidently connected in the closest manner, but in inverse course. It is important to recognise the fact that the process of growth of the connective-tissue elements is an active manifestation of nutritional energy, which, when once excited, may be to some extent independent of its cause. It may, when very active, pass beyond its proportional limits, and be greater than corresponds to the nerve atrophy that causes it, invading adjacent structures as if an inde- pendent process. It may, when very rapid, have some of the cha- racters of an interstitial inflammation, and even an acute inflamma- tion. Such excess is quite unusual ; as a rule the secondary process is subordinate and proportioned to the primary change. These degenerative diseases fall into certain types so far as the spinal cord is concerned, but they are subject to some variety of combination even there, and to great diversity of association with degenerative changes elsewhere. The affection of the cord is of either the sensory or the motor elements, or both. The type of the former is tabes ; of the latter, either spastic paraplegia or muscular atrophy, Recording as the lower segment of the motor path is affected, or the upper. Other combinations of affection will be better understood when the diseases are described. The degenerative diseases are not numerous, but they are of great importance. They are, degeneration of the anterior cornua and anterior root-fibres, causing muscular atrophy ; degeneration of the posterior columns and posterior root-fibres, causing locomotor ataxy; and degeneration of the pyramidal tracts, causing spastic paraplegia, a disease the exact pathological position of which is not qnite certain. These degenerations may be variously combined, and some combioa- tions need separate description. Their causes are various. In some the nutrition of the nerve- elements fails soon after they have achieved maturity, and this is prone to occur in members of the same family. In other cases, which present a contrast to those just mentioned, and yet are allied, there is a senile degeneration, apparently in consequence of less vital endur- ance in these elements of the nervous system than in the other structures of the body. In such cases the local degeneration merely anticipates the somatic death which it too often induces. In these we must assume a,n inherent deficiency of vital endurance in the struc- tures that fail. A similar assumption seems to be the only explanation for the cases in which degeneration of certain elements of the central nervous system occurs in middle life, between thirty-five and fifty, usually as a result of depressing emotion, or of some influence which lessens the general nutrition. Lastly, we are confronted with a large 444 SPINAL COilD, and varied class of cases, in whicli similar degenerations seem to lesult from toxic agents present in the blood. These may be received from without, or generated within the system, and an especially potent source of such toxins seems to be the development of the organisms of some specific diseases. LOCOMOTOR ATAXY; TABES DOESALTS. The malady thus named is the most common chronic disease of the spinal cord. It consists in a degeneration in the posterior columns of the spinal cord, or the peripheral sensory nerves, or both. According to the current views, it is the expression of impaired nutritional in- fluence of the sensory neurons of the spinal cord, primarily of those related to the afferent muscle-nerves, but often also other afferent nerve- systems, including those from the skin. The nutritional centre is in the posterior ganglia, and the toxin apparently acts first on the extremity of the sensory fibres, and also on those that pass into the cord. The effect is manifested, when considerable, by inco-ordination of movement, peculiar pains, defective sensibility, and loss of the myotatic irritability (muscle-reflex action), of which the knee-jerk is the most convenient manifestation. When slight in degree, the sym- ptoms may be limited to the pains and the loss of the knee-jerk. The name "locomotor ataxy" was given to the disease by Duchenne; "tabes dorsalis," or "wasting of the back," is a term applied by Hippocrates to certain symptoms supposed to be due to venereal excess, and long ago limited in Germany to symptoms believed to depend on atrophy of the spinal cord. It then included all chronic paraplegias, but was further restricted to this disease by Eomberg. It has lately obtained wider use on account of the discovery that inco- ordination may be absent when the disease is slight in degree. The symptoms vary much in different cases. Besides the varieties thus produced, there are two allied affections that ought not to be classed with it. One is the so-called " hereditary ataxy." The other is that in which both weakness and inco-ordination co-exist from the first ; " ataxic paraplegia " it may be called. Each differs from other varieties with sufiicient constancy to merit separate consideration. These forms are not included in the following account. HisTORT. — The inco-ordination of movement and other symptoms of the disease were frequently noted, during the first third of this century, in cases of disease of the spinal cord, but such cases were not distinguished from those with actual loss of power. The inco-ordina- tion was found to be associated with disease of the posterior columns by Stanley* The first really exact account of the disease was pub- * ' Med. Gazette,' Feb., 1840, and ' Med.-Chir. Trans./ vol. xxiii. LOCOMOTOR ATAXY. 445 lished in 1847 by Todd,* who distingtdslied tlie cases with inco-ordina- tion and without weakness, from simple paraplegia, and, apparently not aware of Stanley's observation, he inferred (from the character of the symptoms and his theory that the posterior columns contain fibres connecting segments of the cord at different levels) that the posterior columns would be found diseased; and he verified this inference by finding in two cases disease of these columns. The credit of tlie discovery of the disease belongs, if to anyone, unquestionably to Todd, and few diseases can with greater truth be said to have been "discovered." Four years later (in 1851) Eomberg described the disease and the lesion in the posterior o.olunms, but he failed to exclude loss of power from the syraptoms. Russell Eeynolds, in 1855, gave an accurate description of the symptoms, and, in attributing the ataxy to lauscular anaesthesia, was the first to give what we must now regard as the true explanation of the chief symptom. f A series of cases was described by G-ull in 1856 and 1857. Tiirck fijrst observed with the microscope the wasting of the fibres in the posterior columns. Duchenne in 1858-9 published an independent and very able analysis of the symptoms of the disease, and gave it the name "locomotor ataxy." He obtained for it (with the help of Trousseau's "Lectures") the recognition that previous descriptions had failed to secure, and achieved such a degree of success that the malady is called in France " Duchenne's disease." If any name is attached to it, that of Todd alone can be right. Cattses. — The disease is much more frequent, in this country at least, in urban than rural populations. Inherited influence is to be traced only in a small proportion of the cases, perhaps in not more than 10 per cent. It is usually a general neurotic heredity, manifested by such diseases as insanity, epilepsy, and other degenerative diseases of the nervous system. Instances of this are — father epileptic; father insane ; two sisters insane. But in this small percentage the influence becomes insignificant in the presence of the chief cause, to be mentioned presently, since in many instances its coincidence must be accidental. Direct inheritance of the disease is extremely rare (the special hereditary fonn being always excluded). A boy with distinct symptoms and optic nerve atrophy was the son of a man who pre- sented characteristic indications of the early stage of tabes (Eemak). In most instances of this character the inheritance is not direct, being effected by means of syphilis. The inherited disease is probably the only cause of the juvenile form of tabes. Males suffer far more frequently than f emaJes, the proportion being about ten to one, and this seems to imply some proclivity inherent in • * Cyclopaedia of Anatomy and Physiolog-y,' vol. iii, p. 721. + Reynolds, 'Diagnosis of Diseases of the Brain, &c.,' 1855, "Anaesthesia Mas- cnlaris." Certain words are worth quoting: — "It appears most probable that the centripetal tract of fibres is affected, and that the locality of lesion is very variable ** (p. 165). 446 SPINAL COED. the male sex. A like preponderance of males obtains in a disease tliat has a close alliance with tabes — general paralysis of the insane. It is, however, not certain that the sexual difference may not be connected with the wider dissemination of the chief cause — syphilis — among men, and with some peculiar power of resistance to its influence on the part of women. The middle period of adult life is that in which locomotor ataxy usually commences. No less than half the cases begin between thirty and forty, one quarter between forty and fifty, and rather less than a quarter between twenty and thirty. It rarely begins after fifty, but I have once known it to develop at sixty-six. Under twenty it is still more rare, but cases are met with as early as ten, and even in quite young children, the subjects of the cause next described. Among the individual causes, one overshadows all the rest — ^the influence of syphilis. A very large proportion of the sufferers have had, at some previous time, constitutional syphilis, either distinct secondary symptoms or an indurated sore. The proportion is almost as large in the upper and middle classes as in the lower. Of 175 consecutive cases of the disease in men, seen in private practice (in which the past history can be rehed on with more confidence than in hospital patients), no less than 114 of the cases, or 69 per cent., gave a history of a chancre known to be hard, or of secondary sym- ptoms ; and twenty-two others had had a venereal sore of unknown nature. The percentage of those with a history of syphilis or a hard chancre is 77. In another 13 per cent, there was a history of gonorrhoea, in some cases of repeated attacks ; this involves exposure to the risk of syphilis. Patients with unquestionable secondary syphilis are often ignorant of any primary sore. When a disease is a distinct sequel of syphilis in so large a proportion of cases as 69 per cent., we are justified in assuming a similar relation in at least a majority of the cases in which infection cannot be excluded. Gonorrhoea emphasises the inabihty to exclude syphilis, but in no less than 3 per cent, of the total number of cases was there no exposure to the risk of contracting syphilis in the common way. In the lower classes the pro- portion is higher, and has been estimated at 80 per cent., or even more. The ascertainable facts are certainly below the real facts, as I have pointed out elsewhere.* When a deduction is made for possible accidental coincidence, there remains at least one half of the cases in which numerical coincidence must depend on causal relationship. It is probable, indeed, that, taking all cases, a causal proportion of three quarters would be nearer the truth. In women also antecedent syphilis can often be traced, although rather less frequently than in men. At the same time the facts are even more diflicult to ascertain, since in married women syphilis so often runs a latent course. But in the cases of tabes that succeed syphilis the lesion is not syphilitic in histological character ; it is as degenerative as in the cases in which syphilis can be excluded, and it is not influenced by the treatment for syphilis. Hence * ' Lettsomiau Lectures,' 1889. LOCOMOTOR ATAXY. 447 it must be regarded as a degenerative sequel of syphilis rather than as a true syphilitic disease. It is probably the influence of syphilis that determines the greater incidence on the urban than on the rural popula- tion, and the preponderance of cases in middle life. Inherited syphilis is also capable of causing the disease, and is to be traced (as far as 1 have seen) in all cases in children. After the acquired disease the interval between primary syphilis and the first symptoms of tabes varies from one to twenty years. It is, however, rarely less than three years, and in most cases it is between six and twelve years. In rare cases the first symptoms occur diuring the active stage of syphilis.* It is probable, however, that syphilis is not the only cause of the disease. In a, few cases, less than 10 per cent, of the whole, it can be excluded with confidence. The causes operative in these can be traced also in some of the patients who present a history of syphilis, and in such cases the causation of the malady is probably complex. Hitzig and Buzzard have suggested that a toxin having a similar degenerative action may arise from soft sores. One of these causes, which can sometimes be clearly traced, is injury, such as involves concussion of the spine. The immediate results of the injury, whether slight or grave, transient or lasting, are followed by the symptoms of the degenerative malady. In one case a man fell from a height on to the deck of a ship ; transient paraplegia resulted, but six weeks after the accident the man presented extrem«> ataxy, with good power, and no knee-jerk (Arnold). I have known the symptoms to develop gradually a> few months after a fall from a horse. Exposure to cold and wet has occasionally preceded the onse* so directly that it must be regarded as, at least, an exciting cause. There is a history of syphilis in the majority of cases in which the manifestation of tabes f oUows some immediate cause. In other casps * Although an occasional relation to syphilis had been noted by several preceding observers, Fouvnier was the first {\n 1876) to assert the wide extent of this relation. His statements were received with doubt (because syphilitic patients constituted his field for observation), but they were confirmed from the neurological side by myself (♦ British Med. Journal,' March 1, 1879) and Erb (' Arch, f . klin. Med./ July, 1879) ; while abundant corroboration has been since afforded. Many who at first doubted have been convinced by fresh observations. Facts collected without referen«".e to any point at issue are generally worthless, and freshly collected facts have thrown a new light on the subject. The proportion of cases with previous syphilis neces- sarily varies according to the absolute frequency of syphilis. The difierence in the character of the lesion from that of changes known to be syphilitic was urged as an objection, but such considerations are theoretical, and must yield to facts ; in-.tead of denying that this or that lesion can be produced by a given cause, we may have to widen our view of the operation of that cause. Other degenerations of the nervous system seem also to have a relation to syphilis, as I pointed out some years ago ('Lancet,' Jan. 15, 1881). As will be shown in the section on Pathology, recent discoveries lessen very much the difficulty of comprehending the relation- ship by demonstrating the profound influence on the nervous system of chemical toxins generated by the organisms which we have learned to discern as th^ materies morhi of specific diseases. 448 SPINAL COllD. the disease has succeeded excessive fatigue and over-exertion, and also certain acute diseases, especially (it is said) acute rheumatism and typhoid fever ; it perhaps follows diphtheria in rare cases, but most cases have been examples of the ataxic form of diphtheritic paralysis, ultimately passing away. Alcoholic excess has been noted in some instances, but most recorded instances have been due to peripheral neui'itis, involving chiefly the afferent muscle-nerves. Sexual excess has been supposed by some to be a cause ; but its influence can rarely be detected, and its significance is uncertain, since sexual excitement is undoubtedly sometimes an early symptom of the disease. Secondary Tabes. — Symptoms of locomotor ataxy sometimes succeed other diseases of the spinal cord, and such sequence is especially common in syphilitic subjects. Myelitis and syphilitic gummata may be thus succeeded by tabes. An officer in India, who had had syphilis, having suffered for a day or two from pains in the back, took a bath in snow water, and in a few days his legs were absolutely powerless. He gradually recovered power, but could not co-ordinate the movement: as power returned, lightning pains came on, and a year afterwards he presented the typical condition of locomotor ataxy. Again, a man, twelve years after syphilis, had a severe fall, followed by gradual loss of power, so that at the end of three weeks he could scarcely stand. The legs remained weak for a month, and then im- proved, but ataxy came on ; three months later, power was good, inco- ordination extreme. In many cases, however, the ultimate condition is one of combined weakness and ataxy. Symptoms. — A typical case of developed tabes j)resents certain motor, sensory, and reflex symptoms. There is inco-ordination of movement of the legs, sometimes of the arms also, without loss of power or muscular wasting. There are pains in the affected parts, especially sharp momentary " lightning " pains ; there is some loss of sensation ; there is often loss or diminution of reflex action from the skin, and almost always entire loss of the myotatic irritability that is revealed by the so-caUed " tendon-reflexes," and especially by the knee- jerk; there may be retention or incontinence of urine, constipation, and often loss of sexual power. Of this group of symptoms, two usually precede the others — the pains, and the loss of the knee-jerk. These may exist alone, even for years, before inco-ordination comes on. Thus the symptoms are far wider in range than the name " ataxy " suggests ; and while inco-ordination, if it exists, is the most obtrusive objective symptom, it may never be developed. Hence physicians have extensively fallen back on the older term "tabes dorsahs." But recent expansion of our knowledge, especially the discovery of the extent to which the symptoms may depend on disease of the peri- pheral nerves, shows that even the qualifying " dorsalis '* narrows the term unduly, and " peripheral neuro-tabes " has been added to the terminology of the disease. Besides the symptoms above enumerated, others are occasionallj LOCOMOTOR ATAXY. 449 present. Of these tlie most important are atrophy of the optic nerve (and occasionally of other cranial nerves) ; trophic changes in the sl^in, the bones, and the joints ; peculiar paroxysmal visceral disturbances and occasionally motor paralyses and muscular -wasting. The com- binations of symptoms present in different cases vary much. It will be convenient to consider first the individual symptoms in their various degrees, and then their grouping and sequence. Motor Symptoms. — The characteristic inco-ordination of movement develops gradually. It is usually increased (as Eomberg pointed out ) by closui'e of the eyes, and at first may only exist when the guiding influence of vision is thus withdrawn. Before it causes ataxy of movement it may render difficult the maintenance of equilibrium when the base of support is narrowed by the feet being placed close together, toes and heels ; if then the eyes are closed the patient sways, and tends to fall. The effect of closure of the eyes is greatest when sensation in the soles of the feet is defective, but does not depend on this defect ; it may be marked when sensation on the soles of the feet is perfect. The early defect in co-ordination may be discovered by the patient when he walks in the dark or backwards, or, not un- commonly, when he shuts his eyes in the process of washing the face. In a further degree of inco-ordination there is inability to stand with the feet together, even when the eyes are open, and the patient is only steady when the feet are wide apart. If the feet are bare, the diffi- culty is greater, because muscular action has to replace the rigid base of the boot. The irregidar contraction of the muscles is shown by the conspicuous movement of the tendons on the back of the feet. The patient may oscillate from toes to heels before he comes to rest. As the defect progresses, uncertainty is felt in walking even with full visual guidance, especially on uneven ground, or on a very smooth surface. A slight visible alteration in gait is then appreciable, the feet are not placed on the ground quite as in health, or there is distinct difficulty in maintaining equilibrium when the patient turns quickly, and he has to put a foot down suddenly to keep from falling. As the inco-ordination increases, the change in gait becomes greater, but varies much in its precise characters, according to the muscles that are most affected. Often the feet are raised too high, thrown for- wards too far, brought down too suddenly, and the whole sole comes in contact with the ground at once. Often the foot becomes inverted when it touches the ground. Efforts to correct error in movement have themselves to be corrected. In other cases the defect in main- taining equilibrium is greater than the actual disorder of movement of the legs, and the patient sways about in the manner of one who has cerebellar disease ; this probably depends on a preponderant affection of the muscles of the hip-joint. As the defect progresses, the patient is only able to walk by steady- ing himself with a stick, or by taking hold of the arm of another person or of adjacent objects. At first a very slight degree of this help is VOL. I. 29 450 SPINAL CORD. sufficient ; guidance rather tlian support is needed. Afterwards, however, considerable support is necessary, and ultimately the patient may be unable to stand even with help. "When he attempts to rise, the legs move hurriedly forwards and backwards, and if the upright posture is at last achieved, the legs slip forward, and only strong support saves the patient from a fall. The ataxy is manifest also in other movements of the legs. If the patient, when lying, tries to touch an object with his foot, the leg is moved irregularly, goes beyond the place, and then is brought too far back, and only at last does it come in contact with the object, often with unintended force. This inco-ordination, like that in standing, is much greater if the eyes are closed. The arms may present similar inco-ordination, although they often escape, even when the affection of the legs is extreme ; very rarely the arms suffer before the legs (brachial tabes). In one such case there was loss of sensation to touch, not only in the arms, but on the trunk between the epigastric level and the distribution of the cervical plexus. The commencing defect is revealed by delicate movements, such as writing. When slight, it may be conspicuous if the patient tries, with closed eyes, to touch some object, such as his own nose, or, having abducted his arms, tries to bring the forefingers together. As it increases, all movements become irregular ; it is impossible for the patient to button his coat, or to pick up a small object from the table ; the fingers twist about in the attempt. The grasp is not sustained ; first one finger is felt to relax and then another. If the patient attempts to hold out his hand in a fixed posture, it is seen that the same irregularity obtains ; instead of a uniform balanced contraction the muscles contract and relax involuntarily, and slow unintended movements of the fingers result, sometimes closely resembling those of athetosis. The same spontaneous movements may also be observed in the legs. They cease at once when the muscular effort is relinquished. Occasionally the muscles of the trunk present inco-ordination. Thus one patient could sit steadily on a chair when his eyes were open, but if he closed them would at once fall off. The movements of the head, face, tongue, and eyes escape the characteristic derangement. Even with extreme inco-ordination, the power of the muscles may be unimpaired. Occasionally some group of muscles, as the flexors of the ankle, become weak for a little time and then strong again, just as may the eyeball muscles, as we shall presently see. In some cases motor power in the limbs remains unimpaired to the end ; more often, when the ataxy has become great, some muscular weakness supervenes, with or without wasting of the weak muscles There is a distinct group of cases in which weakness and ataxy come on together, but these are considered separately (" Ataxic Paraplegia ") . Sensory symjdoms are prominent in most cases, — subjective sensa- tions, especially of pain, and loss of sensibiKty. Spontaneous pains are present in some degree in nine tenths of the cases of tabes. The LOCOMOTOR ATAXY. 451 most frequent and characteristic are tlie sudden and lancinating pains called " lightning pains." They occur cMefly in the legs, but may be felt in the trunk, arms, and even in the head and face. They are usually paroxysmal, and apt to come on at night ; attacks of such pains last for some hours or for a day or two, varying in seat, but often felt in the same part throughout an attack, or through many attacks. Sometimes they are felt in a limited area of the skin ; at others they seem more deeply seated ; sometimes they dart down the limb. They may correspond to a nerve-trunk (especially the sciatic), but more frequently have no relation to the nerves. They may be felt near joints, but ai-e seldom referred to them. Although the pains are usually acute and " stabbing," they are sometimes of different cha- racter. They may be compared to bad toothache, even when lasting only a second or two. In one patient the sensation was as if both legs were for a moment on fire. The pains in the trunk sometimes correspond in seat to a zone of hypersesthesia, especially when there is a marked " girdle pain." When the pains are referred to the skin, this often becomes tender after the pains have been felt for a time ; the contact of the bedclothes cannot be borne, and even a breath of air can scarcely be endured. Curiously, this may be the case when there is impaired sensibility to pain, but not to touch. When the pain is iu the face it may closely simulate trigeminal " tic ;" only it is on both Bides, and such symmetrical facial neuralgia is very suggestive of a tabetic origin. When pains continue at one spot for some days, vascular or trophic changes may occur there, — ecchymoses have been observed, and I have known the growth of the hair to be changed where pains had been felt in the scalp ; each hair bent and broke off near the skin, over an area the size of half a crown; after the pains ceased the growth of the hair became normal. A sharp pain may be accompanied by a sudden reflex spasmodic movement of the legs, or by inhibitory weakness. Thus, in one case, a sudden pain would often make the patient fall on his knees. The pains may be so severe as to prevent sleep. Other kinds of severe pain, less brief than the lightning pains, occur in some cases, and are described by various epithets, as " burning," ''tearing," "gnawing." Burning pain in the toes distressed one patient. Much more common, and occurring with other pains, are slighter dull pains like those of rheumatism, for which they are often mistaken, an error that is facilitated by the circumstance that any of the pains of tabes may be influenced by weather, being especially in- creased by damp cold. Indeed, this occurrence on any sudden change in weather is often a marked featxire. It is not uncommon for a patient to describe them as " equivalent " to a barometer. They may also be excited by indigestion. Dull pains sometimes precede the sharp pains, occasionally for years. A painful sense of constriction " girdle-pain," is also common, and may be felt aroiond the trunk or in the legs, groins, &c. ; it is sometimes referred to a considerable area — 452 SPINAL CORD. the patient may feel as if tlie whole trunk were tightly enveloped in a cuirass of metal. Darting pains also may be felt in the trunk and not in the legs. Such a sense of constriction is sometimes referred to the legs, especially to the knees, but sometimes to the feet. One patient described this sensation as if an iron band were around each foot. In the arms and hands the pains are usually sHght in degree, and seldom cause real distress ; they are often felt chiefly in the ulnar region. Visceral pains may also occur, usually paroxysmal, and referred to the stomach, bladder, rectum, &c. Pains are not only the most common, they are often the earliest indication of the disease, and may be the only subjectire symptoms in slight and stationary cases. They bear no proportion to the other symptoms, and are sometimes trifling — occasionally altogether absent. They seem sometimes to occur alone; I have seen several patients ■who suffered lightning pains, characteristic in features, course, and general associations, both with and without the pupil symptoms common in tabes, but with no loss of the knee-jerk. The pains are then usually superficial, and the cases may be termed " cuta- neous neuro-tabes." Ataxy may supervene, with loss of the knee- jerk. Sensations other than pain are also common. They are various in character, described as " tinghng," "pins and needles," "creeping," and very often as if the skin, especially of the soles, were covered by some soft substance. Sensations of cold or of heat are also common ; the feet may feel as if the legs are always in cold water ; a sensation of cold about the testicles is occasionally complained of. Similar cutaneous sensations are also common in the hands. They are espe- cially common in the distribution of the ulnar nerve. Here also there may be impaired sensibility, especially for pain and temperature, when the sensory condition elsewhere in the arm is normal. The Tilnar nerve has also been found insensitive to pressure (Biernacki). Increased sensitiveness to pain may also exist, especially on the soles of the feet, and often accompanies lessened sensibility to touch. A diminution of sensibility is also present in most cases of the developed disease. It may involve all forms of sensibility, but seldom equally; some forms may be impaired and others normal. Either pain or touch may be affected alone ; the most frequent change is loss of sensitiveness to pain. Delay of the perception of painful stimuli is a common early symptom, as will presently be described. A firm touch (i. e. slight pressure) may be felt when a slight touch is unper- ceived. When a touch is felt, the power of locaHsing it may be im- paired. Temperature sensations are rarely affected without other forms of sensibility, but they are often impaired with that of paia when tactile sensibility is normal. On the other hand, there may be extensive loss to pain without any defect of the temperature sense. A prick may then cause only a sensation of heat or burning, and extreme degrees of heat or cold cause pain less readily than normal LOCOMOTOR ATAXY. 453 The temperature loss may be partial, — either cold or heat may be •un perceived wbile tbe other is recognised. When touch is slightly impaired, there may be an inability to discriminate differences in the degree of pressure on the skin. Accompanying the diminution or increase of sensitiveness there are sometimes curious changes in the sensation produced. One of these is a delay in the perception of pain, which may amount to several seconds. The greatest delay I have met with amounted to seven seconds, but one of fifteen seconds has been described (Eulenberg). The contact of a point may be felt at once, the pain only after a considerable interval. When felt it may be excessive in degree. Often there is an after-pain, lasting sometimes for a quarter or haK a minute or longer, and the maximum sensation may not be attained until several seconds after the pain is first felt. Thus, in a case in which there was a delay of seven seconds, the maximum sensation was only felt twenty-five seconds after the prick (Obersteiner). Often there is a second or third maximum, a sort of rhythmical recurrence of sensation, quick or deliberate. A delay greater than normal may also attend the sensation of heat, but this is less easy to recognise on account of the time normally required to raise the temperature of the skin. The localising power is sometimes strangely perverted. A touch on the toe may be referred to the back of the foot even when there is no ataxy. A touch or prick on one leg may be referred to the other, sometimes with singular uniformity in position (" allocheiria," p. 14). A prick in one spot may be felt in many places (" polyaes- thesia") on the same, or on both legs. There may also be impair- ment on the face corresponding roughly to divisions of the fifth nerve. Occasionally a patient feels as if the face were covered by a mask, stretching and compressing the skin, a symptom named by Charcot " Hutchinson's mask." The reaction of the sensoiy nerves to elec- tricity may be changed in the same way as that of the motor nerves when they are degenerated ; instead of the earliest sensation, on closure of the circuit, occurring at the kathode, it occurs at the anode (Men- delssohn) . Impairment of sensation is a very variable symptom. It may be absent even when the spontaneous pains are severe. It is most fre- quent, and usually greatest, in the lower part of the legs and feet. It may even be limited to the soles, and usually then ceases at the outer sharp edge of the foot, but extends for an inch or so up the inner side. Touch or pain may be lost on the sole only, and even, strange to say, the form of sensibility that is lost on the sole may alone persist in the legs. Although the sole is usually most affected, sensation may be perfect on the sole when lost elsewhere. One leg is often more affected than the other. The loss may extend to the trunk, and over part or the whole of it. Defective sensibility to touch is sometimes met with around the anus, perinseum, scrotum, &c., and sexual loss is said to be usually issociated with loss of sensibility Ln 454 SPINAL CORD. the glans penis.* The characteristic pain which pressure on the tes- ticles produces is frequently absent. In the upper limbs the impair^ inent of sensation is usually greatest on the hands ; it often commences on the palmar aspect of the fingers, and may be limited to this aspect of the hands, just as it is to the soles of the feet. Sensation may be lost on the trunk and not on the limbs — an important fact, because the anaesthesia may then readily be overlooked. The impair- ment on the trunk frequently ceases when the level of the third rib is reached. On the head, loss of sensation is rare and usually partial. But almost universal defect of sensitiveness to pain over the whole head is sometimes met with. The loss of sensibility is not confined to the skin, but affects the deeper tissues also in many cases. The contraction of the muscles on electrical stimulation may be unfelt, and the muscles may be less sensitive than normal to pressure or forcible extension. It is only from intelligent patients that this can be distinctly ascertained ; but some degree of defect is probably an early change. In a case in which the inco- ordination was much greater in one leg than the other, in the more ataxic leg the muscles were insensitive to traction, which excited a definite sensation on the other side. The muscles may indeed be quite insensitive when cutaneous sensibility is little or not at all impaired. It is probable that the sensibility of the joints, fibrous tissues, and tendons is also involved. The sense of posture may be lost when cutaneous sensibility is intact. The anaesthesia may extend to the viscera when the trunk is involved. In consequence of the loss of sensation, grave injuries to the limbs, such as burns, may be unper- ceived, and visceral disease may be unattended with the customary pain. Pleurisy, for instance, may be absolutely painless. But impairment of sensation is not invariable. There may be no loss even in patients who present considerable inco- ordination, and in those who suffer severe pains, as well as in those who have had none. But it is very rare to have no sensory defect when inco- ordination ia considerable. Reflex action from the skin is usually impaired in proportion to the loss of cutaneous sensibility, and especially to the loss of tactile sensi- biUfcy. It may be normal when pain is unfelt. The plantar reflex is most frequently impaired, and the progress upwards of the disease may be attended by a progressive loss of the gluteal, cremasteric, and abdominal reflexes. On account of the variations met with in health, it is uncertain whether reflex action is ever lessened when there is no impairment of sensation. On the other hand, in the early stage of the disease there is sometimes a considerable and even extreme excess of all cutaneous reflex action. Loss of sexual power is an exceedingly common and often an early symptom of the disease, and may precede any impairment of sensory or reflex functions. As has already been stated, the loss is said as * Brown, ' Lancet,' 1898. LUCOMOTOE ATAXY. 455 a rule to "be accompanied hj loss of sensation in the glans penis. Tet in snch. cases nocturnal emissions may occur, sometimes very frequently. On the other hand, exceptions are met with in which sexual power persists to a late period of the disease, even until after the patient has lost the ability to walk alone. If the condition of cutaneous reflex action is somewhat inconstant, this is not the case with the reflex process on which the myotatic irritability depends. A loss of the knee-jerk, as Westphal first pointed out, is one of the earliest and most constant symptoms of tabes. With it disappear also all other indications of this irritability. In cases with great excess of cutaneous reflex action the knee-jerk is lost as in other cases, and the contrast between the two forms of reflex action is very striking. It is exceedingly rare for the knee-jerk to be obtained in any case of true tabes, but an early case is sometimes met with in which it is not lost, although diminished, and commonly unequal on the two sides. In one or two cases I have found it slight on one side and lost on the other when distinct ataxy was present, and have observed its subsequent disappearance.* In one ca^e, in which the jerk was lost in one leg only, lightning pains were confined to this leg. Yery rarely the knee-jerk persists and is equal, although there are characteristic pains, loss of the iris reflex, and a history of syphilis. The loss often precedes for many years the development of inco- ordination. It is important to remember that a true reflex action may simulate the knee-jerk when it is lost. It is distinguished by the con- spicuous interval between the blow and the movement, by the wide range of this, and by the fact that a similar effect can be produced by a prick on the skin over the patellar tendon. Eye Symptoms. — The functions of the internal muscles of the eye are often affected in tabes. In more than five sixths of the cases f the reflex action of the iris to light is lost ; rarely the action remains perfect throughout. In most cases of reflex loss the contraction m iccommo- dation is preserved, as first noted by Argyll Eobertson, Often also (as Erb has shown) the dilatation that occurs on painful stimulation of the skin of the neck, &c., can no longer be produced. Sometimes the ciliary muscle is also paralysed, causing loss of accommodation. Yery rarely there is loss of accommodation and of the associated contraction of the iris, without loss of the light-reflex. When reflex contraction is not lost it may not be maintained ; the pupil again enlarges ; an actual inverted reaction to light and darkness has been observed. J The pupils are often very small (" spinal myosis "), especially when there is loss of the reflex dilatation from the skin, a loss which seems to be accompanied by atony of the radiating fibres supplied by the sympathetic. The pupils are not always small ; they may be of a * Its return on the paralysed side in a tabetic patient who became liemiplegic, has bpen recorded (Hughlings Jackson and James Taylor, ' Brit. Med. Journ.,' vol. i, 1894). f Berger says 97 per cent. J L'Abundo, ' La Psych iatria,' 1889, vii, p. 286. 456 SPINAL CORD. medium size or still larger, and tlien I have usually found tliat the sldn-reflex can be obtained, although the light-reflex cannot. They are often not perfectly circular, and are frequently unequal. Both eyes are usually affected in the same manner ; occasionally the reflex action is lost in one and only lessened in the other ; this is true also of accommodation ; indeed, almost every possible condition is occasionally met with. On the other hand, the intra-ocular muscles may be unaffected even in advanced cases. According to Berger the ocular te'" ' ui IS often lessened. Paralysis of the external ocular muscles is also common in tabes, and occurs in several forms. (1) Transient weakness lasting a few Fia. 119. — ^Unilateral tabetic ptosis, Fig. 120. — Double tabetic ptosis. days or weeks, and then passing away. (2) Permanent paralysis, complete or incomplete, of a single nerve or part of a nerve. Either form may occur at any stage, but the first is most common in the early, and the second in the later stages of the disease. The transient palsy renders diplopia a common symptom in the early period ; any muscle may be affected, but the external rectus is that which most frequently suffers. Transient ptosis may precede an almost complete external ophthalmoplegia. The persistent palsy may affect one or more muscles ; often the levator is involved, causing what has been termed "tabetic ptosis " (Figs. 119 and 120) . Sometimes the whole third nerve is paralysed. (3) There may be a combined palsy, suggesting a central * Fi om a Salpetriere photograph, for which I am indebted to M. Charcot. LOCOMOTOE ATAXY. 457 origin — as, for instance, loss of tlie movement of convergence asso- ciated with loss of accommodation, alttougli tlie internal recti act in tlie movement towards one side. (4) Many or all the muscles of both eyes may gradually become paralysed — " progressive ophthalmoplegia," internal or external, a condition that is more fully described in the account of ocular palsies in Yol. II. Atrophy of the optic nerve is the most serious ocular complication of tabes. Its frequency is difficult to ascertain, but is certainly less than is often supposed ; it does not occur in more than one case in ten. Atrophy is generally an early symj^tom, usually commencing before inco-ordination is developed, and in a large number of cases ataxy does not supervene ; if it does, the arms are frequently affected before the legs. There seems a tendency for the spinal malady to become stationary when the optic nerve suffers. The disc becomes pale, and its substance shrinks, so that recession begins at its edge instead of at the central " cup," as may readily be perceived by the course of the vessels. The failure of sight usually commences with a peripheral limitation of the field and loss of colour vision, but sometimes central acuity fails early. When this remains good, the peripheral loss may reach a considerable degree before it is suspected by the patient. Earely there is a symmetrical sectorial defect in the fields. The visible pallor of the optic disc is not always proportioned to the failure of sight ; the change in tint depends on wasting of the capil- laries, and this does not always correspond to the wasting of the nerve- fibres. The ultimate tint is grey, or a whitish grey, especially as seen by the direct method. When the disc was very vascular before the atrophy, the grey tint is generally deepest. The vessels are but little narrowed. Occasionally there are slight signs of congestion in the early stage, and then some tissue of gelatinous aspect may develop in the disc, and the vessels may appear somewhat compressed.* The course of the atrophy is usually slowly progressive, and in most oases it ends in total or almost total blindness. It may, however, cease to progress, and even undergo slight improvement. The onset is not always gradual ; sometimes sight fails considerably in the course of a few days, without ophthalmoscopic changes to account for it. I have met with one such case in which double temporal hemianopia indicated disease at the optic chiasma. In such cases the secondary interstitial process probably assumes inflammatory intensity (see p. 443). The atrophy is often more advanced in one eye than in the other, and very rarely one eye only suffers. Flashes of light are occasionally experienced in the course of the atrophy, comparable to the lightning pains in the limbs, but they are not common. Deafness, having the characters of nerve-deafness, is met with in some cases, sudden or gradual in onset, transient or lasting. The persistent deafness has been attributed to an atrophy of the auditory nerve, analogous to that of the optic nerve, but certainly in many * Further details will be found in * Medical Ophthalmoscopy.' 458 SPINAL COED. cases witliout sufficient reason.* Only when tliere is a progressive limitation of the range of hearing, analogous to the peripheral limitation of the field of vision, are we justified in assuming nerve atrophy. I have seen two cases of this kind. In each there was also optic nerve atrophy, and the other symptoms of tabes were distinct.f Attacks of vertigo are frequent in the cases attended by deafness, and seem to depend on the disturbance of the labyrinth or auditory nerve, and to be thus connected only indirectly with the pr.mn.ry disease. But chronic slight vertigo from this cause increases very much the tabetic unsteadiness. Anosmia occasionally occurs, and is probably not infrequent. It is apparently due to an atrophy of the olfactory nerve similar to that of the optic. The functions of the other cranial nerves are not often affected. Pains may be felt in the region of the fifth nerve, and there is occa- sionally loss of sensation in some part of the area supplied by it, on one side or both. Unilateral atrophy of the tongue has been sometimes noted. In the larynx, besides the spasm to be presently described, paralysis of the vocal cords is met with, both as an isolated symptom and also after attacks of spasm have occurred for a long time. Both posterior crico-arytsenoids may be paralysed, and in one case paralysis of one posticus occurred very early in the disease (Eemak). Sphincters. — The functions of the bladder are frequently deranged; there may be either sluggish micturition or a tendency to incontinence, and very often the bladder is not perfectly emptied. These symptoms frequently occur early in the disease, and it may be indeed only for them that the patient seeks medical advice. The retention may become absolute, or there may be overflow incontinence ; there is rarely paralytic incontinence. The imperfect contraction, even when slight, may have serious effects. The residual urine tends to decom- pose, and gradually induces over- distension ; cystitis is apt to occur, and secondary renal disease may develop insidiously, and is a not uncommon cause of death when the difficulty in micturition has been insignificant. Slight intermittent febrile disturbance is a frequent consequence of this bladder incompetence ; it may cease entirely if the catheter is regularly used. The sphincter ani is often also weak, so that a loose stool can be retained with difficulty; but its paralysis rarely reaches a high degree. Constipation is extremely common. * It is very difficult to distinguish an afEection of the nerve from one of the labyrinth independent of the nerve. Even in a case of bilateral deafness coming on in the course of tabes, in which the patient could hear only a loud voice, and deep notea better than high ones, in wliieh atrophy had been diagnosed, Lucae found calcareous masses in eacli of the labyrinths, and the auditory nerves were quite normal. + In one, only notes between E^ and D could be heard. In the other the patient, when first examined, was absolutely deaf to notes above E" and below Gj. A few months later the restriction had confined the range of hearing to the octave in the treble clef between E'^ and E^, even EZ(i being inaudible. Thus the loss occurred: chiefly fiom below upwards. Ultimately no note could h'- licjud. LOCOMOTOR ATAXY. 459 Vaso-motor and trophic disturbances constitute an important group of symptoms, and may reach, a considerable degree without a coinci- dent increase in the other symptoms. Local sweating has been noted, confined, for instance, to the palms and soles, or to one side of the head. The ecchymoses and altered growth of hair, in connection with attacks of pain, have been already mentioned. Pigment may disap- pear from the skin and hair in isolated spots. Herpes of the skin is not uncommon, and usually occurs in association with attacks of pain. A pecuKar association was present in one case; attacks of limited scrotal pain were accompanied by a " rash " on the foreskin. The epidermis of the sole becomes thickened ; blisters readily form beneath it, and may lead to indolent ulcers. The curious affection known as ^-: Fig. 121. — Perforating ulcer of the foot in tabes. (From a SalpStri&re photograph.) " perforating ulcer of the foot " has been found to be almost confined to cases of tabes. Troublesome ulceration of the toes, especially about the nails, is also occasionally met with, and may necessitate amputation. The growth of the nails of the feet, and sometimes of those of the hands, may be changed ; they may be thickened, and the surface furrowed or irregular. The nails may even fall off and be slowly renewed. The teeth sometimes decay quickly, and may drop out. One patient, who had previously lost many of his nails, found that all the teeth of the upper jaw fell out in the course of three days, without any pain or decay. Wasting of the muscles occurs only as a complication in the later stage of the disease. Changes in the nutrition of the joints and bones have attracted much notice since attention was directed to them by the careful investigations of Charcot, whose name is sometimes connected with the condition. They are not very common, but are sufficiently frequent and well marked to place their relation to the disease beyond doubt. The bones may become brittle, and may break readily, in so-called " spontaneous " fractures. The process of union is attended with the formation of a large amount of callus. Sometimes there is also ossi- fication or calcification of the structures adjacent to injured bones, and even of the fibrous tissues independent of the joints, sudx as tlid 460 SPJXAL CORD. intenmiscular and subcutaneous tissues. These may be rapidly in- flamed, and extremely quick swelling may occxir, followed by indura- tion. As the inflammation subsides, there is a remarkable tendency for ossification to occur even in the newly formed inflammatory tissue beneath the skin. Such subcutaneous changes occur most frequently in the foot or thigh, especially near joints, but sometimes in the deeper fibrous tissues between the muscles. In the joints the changes consist of erosion of the cartilage, wasting of the heads of the bones, and ossification of the ligaments ; sometimes irregular bony growths form, and occasionally the head or shaft of a long bone may undergo an extraordinary increase in size by the development of new osseous tissue on the surface. The joint changes may thus assume an atrophic or hypertrophic character, and the movement may be either too free or too limited. Wasting of the head of the femur often renders dislocation of the hip easy. With such changes, and often Fig. 122. — Licomotor ataxy, painless swelling of elbow-joint after a fall on it. One condyle of the humerus and olecranon were found, after death, to have been broken off. Several separate pieces of new bone had formed in the capsule of the distended joint. when they are sUght in degree, there may be great effusion within tlie joints and oedema outside them. The larger joints are those most commonly diseased — ^knee, hip, ankle, elbow, — but the small joints of the fingers have been known to suffer (Westphal). The relative fre- quency with which the chief joints are affected ' is approximately indicated by the following percentage : * — ^knee, 46 ; hip, 20 ; shoulder, 11 ; tarsus, 8 ; elbow, 5 ; ankle, 4. They often occur during the pre-ataxic stage. The lesions are sometimes excited by injury, and the extraordinary changes that may follow traumatic influences, or occur alone, afford a conclusive indication that abnormal trophic in- fluences are at work. Pig. 122 represents the arm of a man who fell and struck his elbow, fracturing the olecranon and condyle. This was followed by extreme painless swelling, and bony masses could be felt, gradually increasing in size. After death the fractures of the bones were found, and masses of new bone had formed in the capsule of the joints. The arthropathic changes occur also, however, without * Obtained by combining the collections of cases of Weizsacker (Bruns' * Beitr, K. kL Chir.,' 1887) and Rotter ('Arch. f. kl. Chir.,' Bd, xxxvi^ LOCOMOTOR ATAXY 461 injury, and are probably due to disease of the nerves, which not only has a direct trophic influence, but also renders the structures insensitive to the injurious effects of prolonged tension or pressure (Rotter). When inco-ordination has developed, the variations in the mus- cular contractions involve varying strain on the ligaments, especially in the case of joints, as the knee, that depend for part of their su23port on — <; i P m %' C b :< '^:' % % -^^. %'~ ;;.|y:.x. Fia. 123. — Locomotor ataxy; retro- flexion of knee-joints. "^ Fia. 124.— Tabetic foot, (From a photo- graph by Mr. Marriott, B.Sc.) the musctdar tendons that pass by them. The knee-joint may thus become so lax that when the patient stands, the joint may become retroflexed, as in Fig. 123. No doubt also this is the result to some extent of the want of tone in the muscles, which has been called by Frenkel hypotonie musculaire. Changes in the tarsal bones and articu- lations may cause the foot to become flat, with a projection inwards or backwards of the tarso-metatarsal articulations, and of the (often enlarged) tarsal bones. The condition has been called the "tabetic club-foot " by Charcot and Fere.* In some cases there is painless loss of teeth, and this may be accom- panied by the presence of troublesome ulceration of the mouth, re- garded by some as analogous to the perforating tdcer of the foot. Visceral symptoms of peculiar character occur in many cases of tabes. t They consist almost entirely of paroxysmal disturbance of function, usually attended with great paia, and have been termed, * The trophic changes in bone and joint have been regarded by some as simple chronic osteo-arthritis, without causal relation to the nerve disease in their subjects, but the evidence is altogether opposed to this view. The arguments that can be adduced in support of it will be found in some of the speeches delivered at a dis- cussion at the Clinical Society, Nov. and Dec, 1885. t The occurrence of attacks of vomiting, sometimes early in the disease, wag pointed out by Topinard, but thought by him to be a mere complication. (Topinard, • De I'ataxie locomotrice,' Paris, 1864, p. 273.) 462 SPINAL CORD. by the Frencli, crises, witli qualifying adjectives according to the seat of tlie symptom. There is a tendency to over-elaborate tliia terminology. The most frequent seat of such disturbance is the stomach, and these attacks are called gastric crises. They consist of paroxysms of severe gastric pain, felt in the epigastrium and often passing through to the back. The pain is accompanied by vomiting, with or without nausea. The vomiting is often incessant, and is first of food, then of clear liquid, which may be very abundant ; ultimately bile is vomited, and sometimes blood, which may be altered in colour ; it has been ascribed to simultaneous vaso-motor disturbance in the mucous membrane. Retardation or irregularity of the action of the heart has sometimes attended such an attack, and rarely pyrexia has been noted. I have known frequent hiccough to accompany the vomiting. Such an attack lasts for some hours or days, and then subsides, to recur in a few weeks. During the intervals the functions of the stomach may be performed in a perfectly normal manner. Although pain and vomiting usually occur together, some patients 'have attacks of pain without vomiting, and in others there is vomiting without pain. It may occur on first rising in the morning, and be relieved by recumbency. Rarely there is nausea alone. A temperate man, in the early stage of tabes, suffered during three years from frequent attacks in which, for several days, he had intense nausea each morning, passing away in the afternoon, and succeeded in the evening by an inordinate craving for food. He never vomited unless he made himself do so, in the vain hope of thus obtaining relief. After two years, attacks of laryngeal spasm were added to the nausea. Occasionally gastric attacks coincide with paroxysms of pain in the trunk. I'he chief intestinal disturbance is constipation, but paroxysmal diarrhoea has been supposed to be of vaso-motor origin, and connected •with the disease (Pierret). Paroxysms of recta] pain (rectal crises) may occur, and may be accompanied by distressing tenesmus, some- times by a sensation as if there were a foreign body in the rectum. In rare cases paroxysms of pain have precisely the character of attacks of renal colic {nephralgic crises), or are felt in the neck of the bladder or along the urethra or at the meatus {vesical or urethral crises). These may be attended by an intense desire to micturate, although the bladder may be empty and only a few drops of urine may be expelled. In one patient such pain was repeated several times an hour, and each attack lasted for several days. Blood may be passed after an attack. Laryngeal crises are, perhaps, after those of the stomach, the most common. They vary much in character. The most common form is a true laryngeal spasm, with noisy inspiration and expiration, cough, and often considerable dyspnoea. The paroxysms may resemble those of whooping-cough or of laryngismus stridulus, and seem to be due to spusin of the adductors. Pressure on the superior laryngeal nerve at LOCOMOTOR ATAXY. 463 its entrance into tlie larynx, or on the trachea, or the introduction of a sound, ■will sometimes induce an attack. The spasm may last for a quarter of an hour or for some hours, but rarely continues so long as the gastric crises. In most if not all these cases of adductor spasm there is permanent weakness of the abductors, which when consider- able constitutes a very grave complication. Whenever there is a history of laryngeal spasm, the respiratory sound should be carefully observed to detect any inspiratory stridor. In one recorded case the spasm spread to the pharynx, making swallowing impossible ; a -violent attack extended to the muscles of respiration, and the patient died asphyxiated. Death from these attacks is, however, rare. Paroxysms of rough cough have been termed ''bronchial crises;" in one case such attacks ceased when the patient began to suffer from gastric crises. Such paroxysmal cough, sometimes ending with a " whoop," is more frequent than definite laryngeal spasm. The definite crises are, how- ever, often early symptoms, and they may continue for many years. I have seen a patient, still in the first stage, who gave a history of gastric crises during the preceding eighteen years. Anginous attacks have also been described. Acceleration of the pulse is common, and cardiac disease, especially aortic, by no means rare. Comparable to these paroxysmal visceral disturbances, although very different in character and more alarming in aspect, are cerebral symptoms ; but these are, fortunately, very rare. They resemble the attacks that are common in general paralysis of the insane, and con- sist of transient apoplectiform seizures, of transient hemiplegia, or of convulsions, general or one-sided. They may occur early in the course of the disease. The alarm they occasion is not without foundation, since death has been known to occur during an attack of apoplectic aspect. Occasionally an actual lesion occurs (probably thrombotic softening), causing persistent hemiplegia, which is probably only coincident with the chronic disease of the nervous system. Paroxysms of vertigo sometimes occur, but their nature is uncertain. They pro- bably frequently depend on derangement of the auditory nerve or labyrinth. Cerebral symptoms may also be superadded, especially ia cases which terminate as general paralysis. Course and Termination. — It is convenient to divide the course of the disease into three stages : — (1) In which there is no alteration in gait, the common indications of the malady being the loss of the knee-jerk and the pains, often associated with loss of the light-reflex of the iris, and unsteadiness on standing with the feet together and eyes shut. (2) That in which there is distinct affection of gait, slight or considerable, but in which the patient is stiU able to walk, alone or with the aid of one or two sticks. . (3) In which walking is possible only with the aid of another person, or it is impossible for the patient to walk or to stand. The first stage is not always present ; inco-ordi- nation may be developed simultaneously with the loss of the knee- jerk, as one of the earliest symptoms. 4G4 SPINAL CORD. The course of the symptoms is extremely Yariable. TBe inco-ordi- nation usually supervenes gradually in tlie course of months, but it sometimes develops very rapidly. I have kaown it to become extreme in the course of a fortnight from its onset, after the first stage had existed for a considerable time. The epithet "progressive,'' given to the malady by Duchenne, expresses a characteristic of a large propor- tion of the cases in which ataxy is developed, and he kaew no other cases of the disease. The inco-ordination, once developed, often increases slowly or rapidly, until it reaches a moderate or a consider- able degree, and the sensory loss shows a like tendency. The local onset of the ataxy seems to be sometimes excited by a peripheral influence, such as injury ; in one case an injury to the left hand was followed by inco-ordination in that limb, afterwards general and cha- racteristic. Still more common is a rapid increase in the symptoms after such a disease as influenza, or in consequence of alcoholic excess. In such cases careful inquiry will generally elicit evidence of preceding symptoms. The pains seldom correspond to the other symptoms in degree or course. They are often very severe in the early period of the disease, and may either lessen or continue unchanged as the loss of sensation develops. Their persistence, even in severe degree, does not show progress in the disease ; once set up, they may continue for years without any increase in the other symptoms, and seem in this to be analogous to neuralgia, being evidence only of functional activity in the altered nerves. The power of recognising the first stage of the disease, which we owe to Westphal's discovery of the loss of the knee-jerk, has enlarged, and in enlarging has to some extent modified, our conception of the general tendency of the disease. It is exceedingly common for the first stage to remain stationary for a long time, for ten, twenty, and eveu, in one case I have known, for twenty-five years, if the duration of the lightning pains may be accepted as proof of its existence. Wl ; en all cases are taken together, and if the patients are subjected to careful treatment, the disease probably shows a progressive tendency in less than one half of the cases. The other symptoms also do not always progress pari passu. Sen- sibility may fail although inco-ordination does not increase. Con- versely, the ataxy may become greater, although sensation remains the same, and even when it shows a distinct improvement. To this we shall return in considering the pathology of the disease. The contrast between the course of different symptoms in some cases is very marked. If optic nerve atrophy develops, the spinal symptoms often remain stationary, and this is also true of visceral crises; I have known gastric crises to cease when inco-ordination came on. In one patient aU the symptoms of tabes passed away, optic nerve atrophy ceased to advance, and even the knee-jerk returned, when the patient became insane. The atrophy of the optic nerves, although generally progressive to blindness, also may become arrested. It may remain LOCOMOTOR ATAXY. 465 limited to o^'' Cy c-, and even when bilateial and very definite, it may cease to increase. The rate of increase in the symptoms of tabes, when this occurs, varies much. Sometimes it is so slow that the ataxy is considerable only at the end of several years. On the other hand, it may be so rapid that in a few months the patient is scarcely able to walk. More commonly the course is variable ; periods in which the disease is almost stationary alternate with others in which the symptoms increase rapidly. The exacerbations may seem spontaneous, or may be dis- tinctly excited by some prejudicial influence— a chill, a fall, or some excess, alcholic or sexual. They are sometimes very acute ; a marked change may occur in the course of a few days, or even in a few hours. Thus I have known a patient to pass, in the course of twenty-four hours, from a condition in which he could walk fairly well to one in which he could scarcely stand. The symptoms suggested that local myelitis had occurred in the degenerating cord. Muscular power may lessen in such a sudden exacerbation, or the increase may be confined to the special symptom of the disease — the ataxy. The conditions thus developed may pass away again, leaving the patient on a little lower level than before, but they often persist without any considerable recovery. There is nothing in the nature of the disease, in most cases, to produce death. The only direct effect of the malady, which has ended life, is laryngeal spasm or paralysis. Even the gastric symptoms, prostrating as they are, are never fatal. Patients who have reached the third stage have lived, bedridden, for twenty years. Death often results from intercurrent maladies, some of which are more dangerous to these sufferers than to others because they may develop painlessly, and attain a serious degree before their existence is suspected. But many patients die from indirect results of the disease. Kidney com- plications are the most common ; they often develop insidiously, and only manifest themselves when life is in peril, as, for instance, by acute febrile symptoms, the exact nature of which may be unsuspected until the urine is examined. I have known a patient, still in the first jStage, die thus after a few days' illness. Whenever obscure pyrexia is met with in diseases of the spinal cord, interference with the function of the kidneys, due to retention of residual urine, should always be suspected and looked for. Bedsores and pyaemia occasionally cause death, although far less frequently than in most other diseases of the spinal cord. Complications. — Occurring, as most cases do, in syphilitic subjects, tabes is sometimes complicated by true syphilitic lesions of the brain or ccrd, generally the later lesions, such as gummata, or sudden palsy from the disease of a cerebral vessel. Acute or subacute myelitis may occur during the course of the disease with characteristic symptoms. Such a complication must not VOL. I. 30 466 SPINAL CORD. be confounded witli the simple acute exacerbation in tlie special symptoms, which, sometimes occurs with remarkable rapidity. Other system diseases of the cord may develop as complications of tabes. The lateral columns may be diseased with the dorsal posterior columns, giving rise to " ataxic paraplegia," but this is a distinct affection, and will be so described. Another occasional complication is muscular atrophy, both the local atrophy already mentioned (espe- cially frequent in the tongue), and general atrophy, such as is met with in the pure spinal form. Thus a gentleman, who had had hemiplegia from syphilitic vascular disease, developed the first stage of tabes — pains, loss of Imee-jerk, loss of the iris-reflex, and slight unsteadiness. He had two courses of mercurial treatment at Aix-la- Chapelle, and at the end of the second, atrophy began in the muscles of the hands, and spread during two years until almost all the muscles of the arms, shoulders, and back became extremely wasted. Local muscular wasting (according to the researches of Dejerine*) is usually the result of degeneration of the peripheral nerves ; it is generally symmetrical. The extensive wasting, as in the case just mentioned, is probably due, as a rule, to degeneration in the anterior cornua of the spinal cord. In rare cases the legs present the symptoms of tabes, while in the arms there is the jerky inco-ordination of disseminated sclerosis, and the co-existence of the two lesions has been demonstrated, but is very rare. Another very important and frequent complication of tabes is general paralysis of the insane. The two diseases have many alHances. It is probable that syphilis is the chief cause of general paralysis, as well as of tabes. E-eflex iridoplegia is common in both diseases. The two maladies are often combined, and the symptoms of one or the other may preponderate. Thus many general paralytics present sym- ptoms of tabes, and its characteristic lesion is found after death. On the other hand, cases of tabes may present slight symptoms of general paralysis, perhaps only slight optimism and mental weakness, which may remain subordinate, or may increase to a pronounced and pre- ponderant degree. It may be difficult to say in which category a case should be placed. It is sometimes said that the disease may com- mence as ataxy, and may change to general paralysis, but a more correct expression of the facts is the co-existence of the two affections, and the dominance of the symptoms of one or the other. Of complications of tabes outside the nervous system, besides the indirect consequences of the malady, valvular heart disease is, perhaps, the most important, and usually develops without any of the usual antecedents, and at an age at which degeneration is unlikely. It is not improbable that the coincidence is really one of cause, the Talvular disease being the result of a syphilitic process. Other * Dejerine, ' Revue de Med.,' 1889. LOCOMOTOR ATAXY. 467 complications are so rare as only to desei-ve notice when a causal con- nection can be traced or reasonably suspected. Coiacident glycosuria has been ascribed to an affection of the medulla oblongata (or may be pro- duced through the cervical spinal cord), but it is extremely rare. But sclerosis of the posterior columns has been shown by Williamson to occur in diabetes.* PATHOLOGiOAii Anatomt. — In most cases the spinal cord presents changes visible to the nakod eye. The poste- rior columns have a grey translucent appearance, which is due to the loss of the nerve-fibres, and to an increase of the connective tissue (" grey degene- ration "). The whole of the posterio- columns may be thus changed, or only parts of them, the distribution of the visible alteration being that of the histological changes revealed by the microscope and presently to be de- scribed. In the hardened cord the difference of tint in the diseased areas is even more distinct than it is in the fresh organ. The posterior columns are also smaller than normal, because the bulk of the connective tissue is less than that of the normal fibres: hence the shape of the cord is slightly changed. Fia. 125. — -Locomotor ataxy involving: the legs only. Sclerosis of the whole posterior columns in the lumhar region, gradually hecoming limited, in the lower dorsal re- gion, to the root-zone and posterior median column. The latter only is affected in the upper half of the cord(aseendino- degenera- tion). There isalso coni^picuous degeneration in the antero-lateral ascending tract. This is rather greater on tlie left side, while the post.-median degeneration is greater on the right, in harmony with the fact that the latter consists of fihres which do not decus- sate. • * Lancet.' 1894. 468 SPINAL COED. In a section of the cord stained with carmine or similar reagent, and examined under the microscope, the affected areas are conspicuous by the deep ' staining of the connective tissue. The position of the excess of this tissue, of the " sclerosis," as it is term.ed, indicates the place in which the nerve-fibres have degenerated. In the most frequent condition, in which the legs only are affected, the sclerosis occupies the whole of the columns in the lumbar region (Fig. 125), but it is often slight in the anterior parts of the postero- external columns, which may even be free from sclerosis ; also in the middle of these columns many more nerve-fibres may be seen than elsewhere. The sclerosis is most dense in the part adjacent to the posterior cornu, through which the posterior root- fibres run, and near the surface of the cord (Fig. 125, d 12). Above the lumbar enlargement the affection of the postero-external columns gradually ceases, but the degeneration is intense in the postero-median columns, and has the distribution of an ascending degeneration, as it in fact is, receding from the commissure in the upper cervical region. (Compare Fig. 125 with Fig. 77, p. 214.) In other cases the external band of sclerosis, adjacent to the cornu, continues separate through the dorsal cord and even through the cervical enlargement (Fig. 126) ; the median degeneration then extends Fio. 12fi, — Tabes with ataxy of the arms as well a " HP]REDITARY ATAXY 519 definitely anaemic cases iron and arsenic are clearly indicated, and they are so probably in all cases. Bone marrow does not seem as yet to have received a trial, but that also in combination with the drugs mentioned would possibly be foxind to have a good effect. Cystitis, bedsores, and contractions must be treated if they arise. The pains may be severe and necessitate morphia, but the need for this may be lessened by injections of cocaine, as recommended in the chapter on Tabes. "HEEEDITART ATAXY" (feiedeeich's disease, heeeditaey ataxic paraplegia). The so-called hereditary ataxy is a form of ataxy, or rather of ataxic paraplegia, depending on combined posterior and lateral sclerosis, which occurs in families, and differs further from the common forms of tabes and of ataxic paraplegia in the early age at which it always commences, and in the presence of certain additional symptom?. It is often termed " Friedreich's disease," because this physician first described the characteristic features of the malady and the lesion in the posterior columns.* The dependence of the disease on a congenital tendency is clearly shown by its usual occtirrence in families. But direct inheritance has been traced in only a few instances. In one, the mother of the family affected, and her mother, both suffered from the disease. That a general neuropathic inheritance is also sometimes effective is shown, by cases in which there is a history of other neurotic diseases, such as insanity or epilepsy, in collaterals or ancestors. Two brothers who were affected had another brother epileptic, and a sister suffered from repeated attacks of chorea. Alcoholism in parents has been supposed to be influential, but the evidence of this is not strong. Consanguinity of parents has existed in some instances, and has doubtless intensified the morbid tendency in these cases. The family tendency of the disease is shown by the affection, in most instances, of brothers and sisters. Thus sixty-five cases were distributed in nineteen families, giving an average of rather more than three to each. The number affected in one generation has varied from two to eight. In the case in which the mother and grandmother * Friedreich's first account was given to a medical society in 1861, and published in 'Virchow's Archiv' (Bde. xxvi and xxvii) in 1863. Fnrthei- cases were published by him in 1876 (ib., Bde. Ixviii and Ixx), and a collection of 57 cases is given by Dr. Everett Smith, ' Boston Med. and Suig. Journal,' Oct. 15th, 1885. See also Ormerod, ' Brain,' Jan., 1888 j Dejerine, ' Med. moderne,' 1890, No. 25, and 'La Sem. Med., 1890, Nois. 11, 12; and especinlly Soca, 'These de Paris,' 1888 (who has collected 165 cases — many, however, doubtful), and Ladame, ' Brain,' 1890, pt. Hi, where a full bibliography will be found; see also Mackie Whyte, * Brain,' 1898. 520 SPINAL CORD. Buffered, an tincle and seven children were also affected, mating ten in one family. Isolated cases have also been recorded, and they seem not to be uncommon. Probably the nature of the affection has not been suspected on account of the isolation. In many of these cases (to judge from personal observations), this feature extends beyond the disease ; the patient is an only child, or the only one of the sex in the family. Thus one patient was the only daughter, and her four brothers were healthy. On the other hand, it is often to be noted that the families in which cases of Friedreich's disease occur are unusually large, as in one family of fifteen, in which three members were affected ; another unaffected, however, transmitting the conditions to two out of four children. The two sexes present nearly equal liability; males slightly pre- ponderate (thirty-five males to thirty females). In some families the two sexes have suffered equally, but in others the disease has shown a marked tendency to affect one sex. Thus in one family of nineteen the two males suffered, and the seventeen females escaped. In another instance, recorded by Musso, a brother and sister (the offspring of a melancholic mother) married healthy individuals ; the brother had three daughters affected out of seven living children ; and of the sister's children three sons were diseased. A curious fact is that three of the brother's and four of the sister's children were born dead. The age at which the first symptoms- are recognised has varied between two and twenty-four years.* The seventh and eighth years of life are those in which disease most often begins ; and next com.es the period of puberty, from twelve to sixteen. In isolated instances the onset is generally later than in the grouped cases. It begins somewhat earlier in males than in females, and often commences about the same period in the same family. Immediate causes can rarely be traced ; preceding acute diseases may have facilitated the onset, but can scarcely have done more. Symptoms. — The first and chief manifestation of the disease is a gradual impairment of co-ordination, first in the legs and afterwards in the arms. Initial j)ains scarcely ever occur, but cramp is occa- sionally complained of. The ataxy is shown by unsteadiness in standing and walking, at first slight, but slowly increasing, imtil the feet have to be placed wide apart in standing, and the patient reels in wallring like one under the influence of alcohol. The feet are not often raised too high, unless when an unusually long step is taken. Closure of the eyes causes a considerable increase in the unsteadiness in most cases ; in some it has but little influence. Children often first * III the family recorded by Everett Smith, the father presented symptoms of ataxic paraplegia at the age of sixty-six, coming on gradually after an attack of rheumatism produced by exposure to cold. In the age of the sufferer this case .stands alone in the history of the disease, and is not included in the figures given. Tiifc case may be a mere coincidftuce, or may show that a latent predisposition may persist through life. ** HEREDITARY ATAXY.** 521 filio-w the affection by the readiness with which they stumble and fall. The impairment of movement in the arms is of a similar character, but usually commences some time after that of the legs. There is irregu- larity in the voluntary movement of the arms and fingers, and the ataxy has often a distinctly jerky character. In most cases the power of the muscles is at first unimpaired ; their nutrition is good, but the myotatic irritability is lost. In most cases the knee-jerk has been found absent as soon as the patient came under observation ; in one case it disappeared after the oth(-r symptoms had set in ; in anothei- it was normal on one side, absent on the other. In several there has been no change long after all the other characteristic symptoms had mani- fested themselves ; very rarely it has been increased, chiefly in untypical cases. As the disease progresses some jerky irregularity develops in the movements of the neck and head, so that the head presents slight unsteady movements, sometimes like an irregular tremor, sometimes closely simulating chorea. Articulation is also impaired ; syllables are €lided; there is a blurred, somewhat explosive utterance, and there may be with this an occasional hesitation. There is no twitching of lips, but occasional jerky movements have been noted in the tongue. The affection of speech is not often an early symptom. It may not be noticed until three, five, or ten years after the onset of the other symptoms. In most cases (but not in all) there is nystagmus when the eyes are moved laterally or upwards. Sometimes the movement is slower than in most forms of nystagmus, and it is rarely present when the eyes are at rest, directed straight forwards. This symptom may come on after those in the hmbs, but careful examination will often reveal it in the early stage. Paralysis of the ocular muscles is very rare ; in one case there was strabismus with double vision,* and slight diplopia sometimes exists for a time and passes away. Optic nerve atrophy never occurs. The pupils are usiially normal, but several cases have been recorded in which there has been loss of the light reflex. Whenever this condition exists evidence of hereditary syphilis should be most carefully sought for, as it is probable that many of the cases in which this loss was met with were cases of true tabes, with some involvement of the lateral columns occurring in young persons, and should not be classed with the disease in question. Sensory symptoms are very variable. Lightning pairs and any severe pains are extremely rare, though in one or two recorded in- stances they have been severe ; but slight dull or rheumatoid pains in the legs are not uncommon. Sensibility has been quite normal in many cases even of severe degree; in others there has been slight anaesthesia in the legs, early in some instances, late in others. In one case there was ■ delay of conduction, such as is met with in tabes ; f rarely sensibility to pain and temperature is impaired. The sense of posture of the limbs has been found normal in several cases in which • Charcot, 'Prog. Med.,' 1887, No. 23. 522 SriNAL CORD. it lias been examined. The electro-sensibility of tbe muscles is said to be sometimes lessened. Increased sensitiveness to pain is occa- sionally met witli. Reflex action from tbe sole is "usually preserved, but may be lost wben there is ansesthesia. The cremaster reflex ia often lost. On account of the age of the patients little is known of the condition of sexual power, but it is certainly often absent. Menstruation xisually becomes irregular and ceases. The sphincters, as a rule, are unaffected. There is no tendency to trophic changes in the skin or joints. Although muscular power is commonly normal at first, and may be normal even when the ataxy is considerable, it usually becomes impaired as the disease progresses, and sometimes weakness comes on, with the ataxy, at the onset of the disease. The loss of power is alwaya greatest in the legs, and may be confined to them. The flexors suffer Yl&. 138. — Showing a condition of marked lateral curvature in Friedreich's ataxy. more than the extensors, and the weakness in the flexors of the ankle may permit some degree of talipes to occur. The loss of power may be ultimately great, although it rarely amounts to absolute paralysis. Slight wasting of the muscles may occur in the later stages of the HEREDITAEY ATAXY 523 disease, attended witli onlv trifling depression of tlie electrical con- tractility ; in two recorded eases, however, a brother and sister, there was great atrophy of mnscles with altered electrical reactions.* Tiateral curvature of the spine, and talipes equinus or equino-varns of the feet (see Figs. 138 and 139.), are common as later results of the Fia. 130. — Showing the characteristic deformity of the feet iu Friedreich's ataxy. muscular weakness, developing under I he influence of posture; and contraction of the flexors of the knees has also resulted. Visceral crises do not occur. Frequency of pulse has been noted, however, in many cases, and curious vaso-motor symptoms (flushing, oedema, sweating, polyuria, and salivation) were present in one of Friedreich's cases. A basic cardiac murmur is of very freqvient occurrence, possibly associated with the anaemia which is frequently present. There is no mental change that can be regarded as part of the disease, although imbecility has co-existed (Power) .f The isolated cases may correspond closely to the type, presenting the same nystagmus, weakness, and unsteadiness ; many of these cases, however, differ somewhat, although sufficiently characteristic in * Dejerjne, 'Med. mod.,' 1890, No. 2.5. t An excellent analysis of the symptoms, &c., is given by Crozier GriflSth (* Trans. Coll. Pliys. Philaddphia,' 1888; and by Ladame ('Brain/ 1890, pt. 52), and Mackie Whyte (' Brain,' 1898). 524 SPINAL COED. tlieir main features to justify their inclusion Speecli more often escapes. I iiave once met with a congenital lisp. In some the sym- ptoms are slight, and have developed late. A difficulty in micturition may precede other symptoms. There are also cases, sporadic and grouped, in which coarse tremor is conspicuous, and the condition might be regarded as one of simple tremor, were it not for the presence or development of other symptoms. For instance, one man had clipping speech "all his life;" between forty and fifty difficulty in writing came on, owing to a peculiar spasmodic tremor in both arms, brought on also in the legs by exertion; at fifty unsteadiness on walking was added. There was a history of a similar affection in several relatives. The rate of progress of the malady varies much, even in different members of the same family. One, in whom the disease commenced last, may be unable to walk, while another who suffered sooner may be stiU in the early stage of the disease. Now and then the disease is stationary for many years. The duration of the malady is corre- spondingly variable. It is always long, even more than thirty years, and in many instances it has not apparently shortened life. On the other hand, death may occur at the end of ten or twelve years. The end has generally come from intercurrent affections, rarely from exhaustion. Acute myelitis has also caused death (Everett Smith). A few years ago, from a consideration of the results of his own observations and those of others, Marie* concluded that there exists a type of disease in many points resembling Friedreich's ataxy, but differing in several important particulars This he called hereditary cerebellar ataxy, and he regarded the symptoms as the result of some congenital defect in the cerebellum. In the ataxy, the articulatory difficulty, the frequent presence of nystagmus, and the fact that the disease might occur in more than one member of the same family, the condition closely resembled Friedreich's disease, but striking differences were manifested in the occasional presence of the Argyll Eobertson pupil, the not unusual occurrence of optic atrophy, and the invariable exaggeration of the knee-jerk. The onset of symptoms also was usually much later in this disease. The remarkable series of cases described by Dr. Sanger Brownf probably belong to this class. They are characterised by the occurrence of a similar condition in many members of the same family throughout several generations, viz. gradually increasing weakness and inco-ordination in the legs, with marked tremors in the head and body, impaired articulation, exag- gerated knee- jerk, occasional ankle-clonus, and frequently optic atrophy. There was no nystagmus and no deformity. Nonne and Menzel have also described similar conditions, but in Nonne's cases the ocular movements were impaired, and there was mental weakness. G-ee.J * ' La Semaine Medicale,' 1893. t 'Brain,' 1892, Summer. J ' St Brtrt.'s Hosp. E,ep.,' voL xxv. HEREDITAET ATAXY. 525 Tooth,* and others have also described a family disease characterised by. symptoms of spastic paraplegia (lateral sclerosis) . Pathological Anatomy.— The lesion in hereditary ataxy is that of ataxic paraplegia and of tabes combined. There is degeneration in the lateral column, often also in the anterior column, such as occurs in ataxic paraplegia , but the sclerosis of the posterior column is more intense than in that disease, and it is also more ex- tensive, especially in tl.e lumbar region It is simi- lar to the degeneration of tabes, and agrees with this also in that the posterior nerve-roots are usually affected, whereas in ataxic paraplegia they almost invariably escape. The distribution of the lesions shows a close cor- respondence in different cases, as will be seen by a comj)arison of the figures here given, which are from three different cases of the disease. The sclerosis Fl&. 140. — Hereditary ataxy ; •section of spinal cord at first lumbar segment. Sclerosis of the whole of the posterior columns except a narrow zone adja- cent to the neck of the horn. Degeneration also of the lateral pyramidal tracts, and, in front of this, sliglit degeneration in the superficial layer of the lateral column. Adjacent to the anterior median fissure there is also a zone of sclerosis of the anterior pyramidal tract, which extends, in this cord, into the lumbar region.f FlO. 141.— Heredi- tary ataxy; dis- tribution of de- generation in the white columns, indicated by the dotted shading. (After Fried- reich.) • • St. Bart.'s Hosp. Eep.,' vol. xxvii. t I am indebted for this section to Dr. Everett Smith, who hag published the case in the ' Boston Med. and Surg. Journal,' Oct. 15th, 1885. The patient was one of three sisters aff'ected with the disease, the brothers being healthy. The father sufl'ered from ataxic paraplegia late in life. In the case from which the drawing is made the inco-ordi nation began in the legs at the age of nineteen, and in the arms goon afterwards, and was quickly followed by loss of power, which gradually increased to almost universal paralysis, with muscular contractures (talipes equino-varus, &c.) and considerable loss of sensation. There were nystagmus, afifection of articulation, and some mental dulness. Death occurred at the age of forty. 626 SPINAL CORD. t'la. 142. — Hereditai^ at.ixy. A, cervical; B, dorsal j C, lumbar regions of the cord. The posterior columns are sclerosed in their whole extent, except in the vicinity of the neck of the horn in the cervical and lumbar regions, the degeneration being rather less intense in the lumbar than in the other parts. In the antero-lateial columns there is an annular zone of sclerosis in the periphery of the cord, widen- ing in the region of the pyramidal traqt. In front of this tract tlie zone is widest in the dorsal region, and trifling in degree in the lumbar. The grey matter is but little affected.* of the posterior coltunna may be complete through- out the cord, with the ex- ception of a narrow band near tlie neck of the cornu, which always remains but little damao-ed. In the lumbar region it is usually intense up to the head of the horn and the posterioi surface of the cord ; occa- sionally, however, it is some- what less intense in this re- gion than it is higher up, extending, nevertheless, into the root-zone. In the cer- vical region the sclerosis may also be general, or it may be greatest in the root- zone and in the posterior median columns. The cer- vical root-zone never ■ es- capes, as it often does in tabes. The degeneration of the lateral columns always in- volves the pyramidal tracts, and is most intense in their position. It is not, how- ever, Umited to them. It usually extends outwards to the periphery of the cord, even where the pyramidal tract does not reach the surface, thus involving the direct cerebellar tract ; and it also extends forwards at the surface, so as to con- stitute a band of annular sclerosis, which varies ia thickness in different parts of the cord and in different cases (rigs. 141, 142). In * For the sections from which the drawing is made I am indebted to Dr. Pitt (who prepared them) and the late Dr. Moxon, under whose care the patient died in Guy's Hospital. The case (full details of which will be found in a recent volume of the * Guy's Hospital Reports ') is one of a series of five cases (four brotherg and « HEEEDITARY ATAXY. 527 the inner part of the anterior column there may be a distinct area of degeneration in the position of the anterior pyramidal tract. This is seen in Fig. 140, in which this tract extends unusually low in the cord, and is distinctly degenerated m the upper part of the lumbar enlargement. Atrophy of the poste- rior vesicular column has been found a. :o- f ciated with that of the direct cerebellar tract. Slight abnormal ap- pearances have been seen in the nerve- cells of the anterior cornua in some cases, but as a rule these are normal, and the grey matter presents no other dis- ease. It is very likely, however, that future observations will reveal the occurrence of changes in the nerve- cells of the posterior horns, such as are met with in tabes. The pia mater over the posterior columns has been found thickened. The posterior nerve-roots usually present some degeneration of their fibres; this may be partial (Fig. 143, b), or may amount to total destruction of the fibres (as at c). The peripheral nerves in the limbs have been found normal.* Some general shrinking and induration of the pons and medulla were found by Friedreich, with atrophy of the cells of the post- pyramidal nucleus and some degeneration of the restiform bodies, but none of the anterior pyramids. Corpora amylacea were present in the hypoglossal nerves. Atrophy of the cerebellum, pons, and olivary bodies was found in one case ; the cells of Purkinje were diminished in numbers, but showed no sign of atrojohy or degeneration. f There was also degeneration of the hypoglossal and facial nuclei. This defective cerebellar development is the condition supposed to sister) which I reported some years a,;o to the Clinical Society (' Clia. Soc Trans./ vol. xiv, 1881, p. 1). * Friedreich, • Virchow's Archiv,' Bd. Ixx, p. 145. t P. Meuzel, 'Arch. f. Psych./ Bd. xxii, H. 1, p. 160. VC Fia. 143. — Hereditary ataxy J degeneration of poste- rior nerve-roots (from the same case as Fig. 142). A, normal interior root, for comparison. B, posterior root, partially desenerated ; a few normal nerve- fibres are seen, but most of the spaces which should contain nerve-filires are empty. C, posterior root, totally degenerated, probably by a more acute pro- cess than that of B, since there is some destruction of the septa and increase of amorphous connective tissue. The products of degeneration are rendered invisible by the mode of preparation. (Compare C with the similar chano^es in a totally degenerated peripheral nerve shown in Pig. 59 B, p. 165.) 528 SPINAL COED. underlie tlie manifestations of tlie condition already alluded to as the hereditary cerebellar ataxy of Marie. In another case * the anatomical condition reyealed the absence of cord degeneration, but the cere- bellum was small, and the cells of Purkinje deficient. In the only one of Sanger Brown's examined, however, there were sclerotic changes in the lateral and posterior columns, but no marked cerebellar changes were present, although the cells of Purkinje are said not to have been over-abundant. A case, similar in clinical conditions, was many years ago described by Eraser and Coats of Glasgow, and in this also there was no cord change, but marked atrophy of the cerebellum, and a de- fective development of the cells of Purkinje. It is of some interest that a condition has been described in cats congenitally ataxic, in which the cerebellum is small, and Purkinje's cells absent, or defective in character and number. Pathology. — The disease apparently occupies a clinical and patho- logical position between the combined sclerosis described as ataxic paraplegia and s^imple tabes, resembling the former in the common affection of the lateral and posterior columns, and the consequent weakness with ataxy — resembling it aTso in the imperfect hmitation of the changes, and in the intensity of those in the middle of the pos- terior columns in the dorsal region ; but it differs from this, and resembles tabes, in the degree of affection of the posterior columns in the lumbar regions, the extension in sHght degree into the root- zones, and the affection of the posterior roots : with these the loss of the knee-jerk and the affection of sensation are apparently connected. The isolated cases, occasionally met with, present the same combina- tion of spinal symptoms. The precise origin of the affection of articulation and of the nystagmus has not yet been traced. The age at which the disease commences, long before the period at which ordinary degenerations occur, and its family grouping, suggest that its ultimate cause is a congenital tendency of develop- ment, by which the affected elements have a briefer period of vital endurance than the other tissues of the organism. Mobius has suggested that there is an actual arrest of develojoment of these structures, but it is evident that their development suffices for perfect function during the early part of life, and that their functional capacity undergoes subsequent failure, which can only be due to a process of structural change. It is possible that we have here, again, a double morbid process, and that a tendency to early degeneration in the nerve-elements is associated with a converse tendency to over- growth of the interstitial tissue, analogous to that which we have in the muscles in pseudo-hypertrophic paralysis (q. v.). In this con- nection it is important to note that in one case the neuroglial over- growth suggested a pure increase of the normal tissue, rather than a result of inflammation ; and the peripheral sensory nerves, although • ' Notme, ' Arch, f . Psych.,' xxii, 1891. " HEREDITARY ATAXY." 529 not degenerated, contained a considerable nnmber of embryonal nerve- fibres hi the fasciculi.* Dejerine would regard the neuroglial increase as the sole element in tbe morbid process ; but the fact last mentioned, as Tvell as the preponderant affection of certain tracts, makes it improbable that this exclusive view is correct. Although we have here only to consider hereditary cerebellar ataxy and similar conditions, in relation to Friedreich's ataxy, it may be stated that in this disease also we probably have to deal with a developmental defect or perversion, as has been indicated in con- sidering the morbid anatomy. And the same may be said of the family form of spastic paralysis. It might already seen as if we had a series to deal with, with Friedreich's ataxy at one end and family spastic paralysis at the other, the intermediate space being occupied by cases like those of Sanger Brown, in which spasticity and ataxy are combined, and in which the underlying anatomical condition as regards the cord is one of sclerosis affecting lateral and posterior tracts fairly equally, while in Friedreich's disease we have to deal with a condition in which the posterior columns suffer most, and in family spastic para- lysis with one in which the lateral columns may be exclusively affected. Diagnosis. — In most cases the inco-ordination is sufficiently pre- dominant to suggest that the disease is a form of ataxy, and the unsteadiness of the head, the affection of articulation, the nystagmus, and the age at onset, suffice for the distinction from ordinary tabes. The common form of ataxic paraplegia bears a close resemblance to this disease, a resemblance that is more than superficial, although the excessive knee-jerk and foot-clonus, almost always present in ataxic paraplegia, are usually absent in hereditary ataxy ; much spasm is always absent, and nystagmus is common. The difference in the state of myotatic irritability is, as we have seen, not absolute; cases of combined lateral and posterior sclerosis occur, of tabetic type, in which the knee-jerk is lost, and in at least one case of hereditary ataxy the knee-jerk has been excessive. The age of onset and family multiplicity may decide the question, but the isolated cases, which are by no means rare, commencing soon after puberty, are not dis- tinguishable from the hereditary disease ; they seem to be analogous to the isolated cases of pseudo-hypertrophic paralysis. A greater diffi- culty is presented by cases of slight tabes in children, the subjects of inherited syphilis, in whom it is not uncommon for some weakness of the legs to co-exist, or speech to be disordered, in consequence of some early lesion of the brain. The loss of the iris-reflex should suggest inherited syphilis, and other indications of this will often decide the nature of the case. Disseminated sclerosis presents inco-ordination, nystagmus, and impaired articulation, but the ataxy of the arms differs in the wide range and violent character of the disordering jerks which characterise this disease ; while simple unsteadiness of the legs is very rare, and * Auscher, ' La Semaine Med.,' 1890, No. 32. VOL. I. 34 530 SPINAL COED. the course of tlie malady is more rapid. The affection of speech differs from that of hereditary ataxy in being simply " staccato," with undue separation of syllables, in the marked cases. In many in- stances, however, the articulatory defect is similar in the two dis- eases. The cases are always isolated. Cerebellar tumour and hereditary ataxy can hardly be confounded, in spite of the fact that the unsteadiness in walking is very similar in the two diseases ; the common affection of the arms in the one, and the conspicuous head symptoms (severe pain, optic neuritis, &c.) of the other, sufficiently distiaguish them. It is very common for the tremor of the head to be at first ascribed to mere " nervousness," and also for the isolated form, in girls, to be regarded as hysterical. The presence of nystagmus should at once decide the question; it is absolute proof of definite disease. Peognosis. — The prognosis in every case is very serious, since the disease, being a developmental affection, is essentially progressive; but life may be prolonged for many years, and in slight cases the malady may interfere comparatively little with the patient's occupation. Thus I have known a man, with very marked symptoms, follow his business as a tradesman for many years. The only guide to individual prognosis is the observed rate of progress, which has little relation to the age at which the symptoms commence. Treatment. — As in other diseases that depend on a congenital tendency, treatment is almost powerless. The measures recommended for ordinary locomotor ataxy (apart from those suggested by the special symptoms of tabes) are those most suitable to the hereditary form. Arsenic, phosphorus, and nitrate of silver deserve a trial ; now and then they seem to check the progress of the disease for a longer or shorter time, but its individual tendency determines its course, almost irrespective of treatment. SIMPLE SENILE PARAPLEQIA. This name seems the most unobjectionable for a condition, some- what rare, which appears hitherto to have been unrecognised.* It is confijied to late life, occurring in those over 40, and especially over 50. Its characteristic is simple weakness of the legs, with some slowness of movement, but without wasting, sensory disturbance, or reflex altera- tion. The knee-jerk is normal, and there is no foot-clonus. The malady develops very gradually and is slowly progressive, although it seems seldom to attain such a degree as to prevent standing. The rearm muscles. The rounded contour of the shoulder becomes changed (Figs. 7, 144, 145), and the head of the humerus can be recognised beneath the acromion. It is not rare for part of the del- toid to suffer and part escape : we have seen (p. 36) that the several portions have different functions and associations, and this probably involves a relation to separate groups of nerve-cells. The wasting of the deltoid is soon followed by that of the other muscles of the upper arm and of the scapula. The triceps usually suffers less and later than the biceps, but sometimes the reverse is the case. The supra- and iafra-spinati are often affected with the deltoid. In exceptional 536 SPINAL CORD. instances tlie deltoid or hand muscles escape, and tliere are casea (perhaps a special group) in which, the upper arm and shoulder muscles waste even to an extreme degree, and the forearm and hand muscles escape entirely. In most cases, the wasting early involves the muscles of the back, and it sometimes begins in them. The middle and lower parts of the trapezius usually suffer first ; the rhomboids and erectors of the spine at a later date. The affection of the trapezius is readily recognised if the patient tries to put the shoulder back CPig. 145) . Thehighest Fig-. 144. — Progressive jiiuscular atrophj. Wasting of the raus- cles of the back and arms ; in the forearm scarcely any muscular tissue can be recog- nised, and in the hand all the muscular pro- minences have van- ished. (Drawn by Dr. H. R. Spencer.) FlG.145.— Progress! ve musciilar at rophy. Wasting of right trapezius complete (the rhomboids remaining), of the left trapezius partial. On each side the tipper part of the trapezius is wasted, and the contour of the neck is cor- respondingly changed. Both deltoids are also atrophied. (Drawn by Dr. Spencer.) part of the trapezius presents a remarkable indisposition to atrophy ; it often remains intact to the last, and then may contrast with the wasting below it, standing out on each side, like a cord passing from the occiput to the shoulder. Hence Duchenne termed this part the ultimum moriens. I have, however, seen several otherwise typical cases, (beginning either in the deltoids or in the hands,) in which the highest parts of the trapezii suffered before the middle parts. The levator anguli scapulae also generally escapes, even when all the OHKONIO MUSCULAE ATROPHY. tmiscles about it are wasted. Tlie serratus, latissimus, and pectoralis major are usually affected later. They may escape wholly or in part ; isolated bundles of the pectora''*s may waste, the intervening parts escap- ing, or either the upper or lower part of the muscle may atrophy alone. According to the affection of the muscles that are attached to the scapula, the position of the bone changes, and it becomes rotated under the influence of the muscles that are unaf- fected and unopposed (Fig. 7, p. 35). The muscles that extend the Fig 146. — Progressive muscular atrophy. Weak- ness of the muscles of the neck. A, habitual posture of the head, inclined backwards. B, posi- tion into which it falls if- the patient attempts to keep it in the normal balance. (Drawn by Dr. Spencer.) head on the spine often suffer in con- siderable degree, and from this there results a difficulty in the carriage of the head (Fig. 146). It is habitually inclined back- wards, so as to balance it on the spine with but little muscular exertion ; if moved forwards, it falls so that the chin touches the chest. It can be brought back into its former position only with diffi- culty ; the patient has to incline the trunk backwards, so as to bring the head nearly into the vertical position, and then, with a sudden contraction of the sterno-mastoids, and a jerk, the head goes back into its former posture. The increased innervation of the weak extensors of the head often causes a synergic over-action of the frontalis muscles, which are normally associated with the extensors (so that the eye- brows are raised when the head is put back to look upwards.) The skin at the back of the neck lies in transverse folds when the neck is extended. The patient may be unable, when lying in bed, to move the headf rom side to side. The sterno-mastoids also are often wasted ; either the sternal or clavicular part may be most affected. In striking con- trast to the general wasting of the neck is the condition of the platysma myoides, which always escapes, and may become hypertrophied in a vain attempt at compensation. The muscles of respiration suffer in the majority of cases, and their impairment constitutes a grave source of danger to life. The inter- costals rarely escape altogether ; the diaphragm is involved in many cases, and respiration is then carried on by the intercostals and superior thoracic muscles. On the other hand, the intercostals may suffer much and the diaphragm remain free; respiration is then purely abdominal, and the walls of the thorax may be almost motionless in breathing, or there may be merely a slight movement of elevation of the upper ribs. The chest becomes flattened in front, and narrow from 638 SPINAL COED. before back, from tlie influence of atmospheric pressure on the ribs, unopposed hj the intercostals. Either the upper or lower intercostals may suffer most. When the diaphragm is paralysed the upper chest muscles often suffer more than the lower, and a compensatory increased movement of the lower ribs carries forward the abdominal wall, and may suggest that the diaphragm is acting when it is not. A careful examination will always prevent the error. The muscles of the abdo- minal wall occasionally waste, but far less frequently than those of the thorax. "Wasting in the legs is much less common than in the arms, and if it occurs is usually slighter in degree ; but occasionally the disease first manifests itself in the legs, and is more intense in them than elsewhere. The glutei, extensors of the knee, and the muscles in the front and on the outer side of the lower leg, are those that are most affected. We shall presently see, however, that the legs are often paralysed when they are not wasted, and sometimes they are the seat of wasting which differs in certain features from that which is the especial characteristic of the disease. The face almost always escapes the general atrophy, and its normal appearance may present a striking contrast to the rest of the body. In some cases, however, the lips are paralysed as part of the bulbar palsy that so often accompanies the spinal disease. A remarkable case in which the face shared the atrophy of the limbs, and the tongue escaped, has been recorded by Langer ;* on the other hand, the tongue has been the first part to suffer, the arms being affected a month later.f Bulbar paralysis, however, often runs its course without muscular wasting in the limbs, and when the latter supervenes it is generally quite subsidiary. The like statement may be made of the converse relation, although it must be remembered that the anterior nerve-cells and those of the bulbar nuclei are analogous structures, and may be similarly and even simultaneously affected. As the wasting progresses, the appearance of the parts in which it is most advanced becomes extremely changed. All trace of muscle may disappear from parts of limbs or even from an entire limb (Fig. 144) ; and there is usually a wasting of the adipose tissue as weU as of the muscle, so that the bone seems to be covered only by fascia and skin. The transverse processes of the vertebrae may be felt in the hollow beside the spine, and the bony prominences about the shoulder may be almost as conspicuous as in a skeleton, so that beneath the acromion there may be a groove, into which the finger can be placed, in consequence of the descent of the head of the hujnerus from the glenoid cavity. The unequal affection of antagonistic muscles leads to various contractions and deformities. In the hand, especially, distortion is apt to occur ; from preponderant paralysis of the interossei and contraction of the long flexor and extensor muscles, * Vienna Medical Society, March 17th, 1882. t Biidsall, ' Journal of Nerv. and Ment. Dis.,' 1887, xiv, p. 256. OEEONIO MUSCULAR ATEOPHT. 539 the ** claw-Hire hand " develops in extreme degree (Figs. 19 and 20, p. 43). If all the muscles of a part are equally and simultaneously affected, no deformity results unless an unsupj^orted part yields to the influence of gravitation (Fig. 144). Lordosis is very common in cases in which the trunk and hip muscles are involved. It is often the indirect result of the weakness of the extensors of the hip- joint. It is produced in the manner described in the account of pseudo- hypertrophic paralysis, in which it is almost constant. The electrical irritability of the wasted miiscles presents changes which vary in character in diiferent cases. When the wasting is slow, there is usually a diminution in both faradic and voltaic irritability, similar in character to each current. But the amount of contraction that can be produced is far less than normal, and progressively lessens. The irritability fails with the muscular nutrition, and when the wasting is great, only a slight contraction can be obtained, even with a strong current. When the wasting is extreme, irritability at last becomes extinct, but. the voltaic irritability of the musciilar fibres persists long after the faradic u'ritability has disappeared. It may be normal in degree, or lowered, but is seldom increased in such cases. The quality of the voltaic irritability may also be normal, but some- times ACC (anodal closure contraction) occurs as readily, or more readily, than KCC. Tetanic contraction, during the passage of the current is produced with undue readiness compared with the closure contractions, and opening contractions are often caused by currents but little stronger than those that cause closure contractions. Thus there may be the qualitative change of the reaction of degeneration without the voltaic increase (see p. 74). When there is the rapid and considerable paralysis described on p. 644, either at the onset or during the course of the disease, the palsy being followed by rapid wasting, there may be quick extinction of faradic, with actual exalta- tion of voltaic irritability, and the reaction of degeneration may be present in all its characteristics. Between these forms every inter- mediate condition may be met with, including the mixed reaction described on p. 32. The mechanical irritability of the muscles is considerably increased ; a tap causes a local contraction of the fibres struck. Moreover, spontaneous flickering contractions of parts of the muscles are very common, now of one bundle, now of another, conspicuous to the eye, although scarcely felt by the patient. This " fibrillation," as it is termed, is not invai-iable, nor is it confined to this disease. It may sometimes be observed in muscles that are not yet invaded by the wasting, but where it is observed, in this disease, atrophy usually follows. In the parts affected by the characteristic wasting, all reflex action is abolished, clearly in consequence of the damage to the motor part of the reflex arc ; the afferent portion of the arc is unaffected, for, as we shall see, there is no loss of sensation. The myotatic irritability 540 SPIIJAL CORD. ("tendon-reflex action") is also lost, and lost early. The knee-jert, for instance, disappears as soon as there is even a slight diminution in the bulk of the thigh muscles, in cases in which the legs are the seat of primary wasting. The muscles are flaccid and toneless — a condition that may be termed " atonic atrophy." To this common rule, however, exceptions are sometimes met with ; there may be from the first rigidity of the affected muscles. When this is the case, the wasting does not go on to the entire destruction of the muscle ; often it is considerable, but not extreme, and it may be trifling. "With this rigidity there is a preservation or even increase of myotatic irritability. We may term this "tonic atrophy." It is generally associated with spastic para- lysis, without wasting, in some other part. For instance, in one case the forearms and hands were the seat of this tonic atrophy, and in the legs there was simple spastic paraplegia . We shall presently consider the pathology of this condition.* Sensory symptoms are always subordinate and usually very slight. They are confined to pain, usually dull and rheiunatoid in character, felt chiefly in the limbs in which the malady is most active. Such pains are common at the onset, as we have already seen, and they may recur from time to time during the course of the disease. Sometimes vague feelings of " numbness " or " deadness " are complained of, but cutaneous sensibility is never impaired. (When anaesthesia accom- panies muscular wasting, both symptoms are due either to chronic meningitis, damaging the nerve-roots, or to disseminated focal myelitis, syringomyelia, or multiple neuritis.) Nor do the muscles lose such sensibility as they normally possess. Perception of posture persists, and the muscles continue sensitive both to pressure and to exten- sion. When the arms are the seat of such atrophy as has been described, the legs, if not also wasted, may be normal, or they may be slightly affected, the thighs thin, and the knee-jerks lost. Often they are the seat of gradual loss of power without wasting, and with an increase of myotatic irritability. The knee-jerk is excessive ; a clonus can readily be obtained, and the reflex over-action of the muscles may ijicrease to actual rigidity and spasm, so that there is the condition of spastic paraplegia described in a preceding chapter. It is rare, however, for the spasm to reach the higher degree of intensity, and for the muscles to present the massive firmness that characterises the simple form of spastic paraplegia. On the other hand, there is often some diminu- tion in the size of the muscles, and thus we have a gradation to the condition of tonic atrophy just described. In this condition, moreover, * It should be noted, however, that, in the muscles that are the seat of toneless wasting, when the atrophy has attained an extreme degree, slight rigidity may develop, accompanied by tenderness of the muscle. It is probable that this rigidity is myopathic, and due to the structural changes in the muscles presently to be described. This condition is rare : the early flaccidity is usually maintained to the last. CHEONIC MUSCULAR ATliOPHY. 541 there is usually only a moderate diminution in electrical excitability, ■which does not go on to extinction. The one condition does not seem to pass into the other ; the state of rigidity and myotatic excess does not give place to muscular relaxation ; atonic atrophy does not succeed the tonic wasting. In very rare cases, of which I have seen a few instances, there is a similar condition in the hands when the shoulders are the seat of simple atonic atrophy. The forearms are then rigid^ moderately wasted, with myotatic excess, while the muscles of the shoulders are extremely wasted and absolutely flaccid. In still more rare cases the whole arms are thus affected, are thin and rigid, and in no part is there atonic atrophy. In one remarkable case of this character, the muscles of the trunk participated in the spasm ; after coughing or yawning, respiration would be checked for a few seconds by general spasm, and whenever the patient was raised from the bed, the arms, legs, back and neck became stiff in tetanoid rigidity, the head being bent backwards. The combinations of the ordinary atonic wasting, and loss of power without wasting and with increased myotatic irritabihty, are exceed- ingly numerous and variable. The most frequent, as ah'eady stated, is flaccid atrophy in the arms and spastic paralysis in the legs ; but I have twice seen atonic atrophy below the knees, with weak but •well-nourished thigh muscles and much increased knee-jerk. The variable combination of these conditions gives rise to differences that are more apparent than real, and may easily be allowed undue weight in classification. Their explanation will be considered presently. The extreme emaciation of the most affected -parts shows that the adipose tissue wastes as well as the muscles. Indeed, the sufferers usually become generally thin, often to an extreme degree. The atrophied limbs are usually cold, and may be livid or pale, but there is no tendency to acute vaso-motor disturbance in the ordinary form of the disease. I have known the skin of the face to become thin and smooth, so that, in one instance, the dark iris could be seen through the closed eyelids, but such a change is quite exceptional. In another patient there was a very remarkable form of local atrophy. Certain areas of muscles underwent wasting, the rest being normal ; the aifec- tion commenced by a livid discoloration of the skin, and the wasting seemed to involve the skin, subcutaneous tissue, and muscle, causing local depressions. Considerable tracts of the trapezii were thus affected, and smaller spots in the arms and legs. The patient was a single woman of thirty-five, and the disease, which did not show a strongly progressive tendency, is probably a special affection, perhaps of the nature of scleroderma. The functions of the sympathetic are not, as a rule, deranged. Dilatation or contraction of one pupil has been frequently observed, chiefly in association with atrophy of the muscles that are supplied from the lower part of the cervical region ; and it no doubt depends on the disease of the spinal cord, and not of the sympathetic itself. 542 SPINAL COED. The reflex action of the iris is usually normal, and optic nerve atrophy never occurs.* Nystagmus is present in rare cases. The visceral functions are usually little disturbed. Sexual power is often lost. The sphincters rarely suffer, even when the wasting is general and extreme; occasionally they are involved, and they may even suffer early. In other cases, in which the legs become weak after the wasting sets in in the arms, the affection of the sphincters may coincide with that of the legs. In the composition of the ui'ine, slight changes have been found, but not constantly. Urea has been increased in some cases, lessened in others. f The quantity of lime has been found to be increased (Fromman), that of kreatin diminished, even to one tenth of the normal (Rosenthal, Langer) . Glycosuria has been observed in association with bulbar symptoms. J The lungs may suffer from the impairment of breathing power, when the intercostals and diaphragm are weakened. Varieties. — The chief varieties of the disease depend on the relative distribution of the three conditions: (1) atonic atrophy, becoming extreme ; (2) muscular weakness with spasm, but without wasting, or with only slight wasting; and (3) tonic atrophy, rarely extreme in degree, with myotatic excess. The commonest condition is to have atonic atrophy in the arms and upper part of the trunk, with simple weakness and spasm in the legs. Atonic atrophy in both arms and legs is less common, and the least common is tonic atrophy alone, in the arms, or universal. The last is, indeed, extremely rare. It is important to note, however, that these conditions may coexist in every degree and combination ; between universal atonic atrophy on the one hand, and universal spastic paralysis without wasting on the other, there is every gradation. The latter does not come into the category now under consideration, but similar cases are met with in which there is atrophy of a few muscles (as, for instance, of the hands only), which complete the series. The varieties due to the different combinations of atrophy and paralysis have been already alluded to. A peculiar form of muscular atrophy has been mentioned, first * I have once met with a remarkable reflex fixation of the eyeballs in a case of advanced progressive muscular atrophy. If the patient, looking to one side, was suddenly told to look at an object on the other side, his head was instantly turned towards the second object, while the eyes remained fixed on the first, by a movement corresponding to that of the head but in the opposite direction, and then, after a few seconds, they were slowly moved towards the second object. The phenomenon continued to the end of the patient's life. As I pointed out in an account of this curious condition (' Brain,* vol. i), it is interesting evidence of a normal reflex mechauiam in the fixation of the eyes ; this was, as it were, isolated by disease, which lessened voluntary control over it. t In a patient who weighed 7 st. 13 lbs., and whose urine varied between 760 and 960 cubic centimetres, 1 found the daily excretion of urea to vary between 10*7 and 15 grammes, the average being 13 grammes. This is just half the normal average for a man of that weight, which would be (according to Parkes) 24 grammes. X Rovighi and Meiotti, 'Riv. Sper.,' 1888, p. 315. CHRONIC MUSUULAE ATEOPHY. 543 conspicuous in the peroneal regions * and spreading thence to other muscles of the leg and to the hands. It is characterised bj occurrence in early life, and often in several members of the same family, and has been termed the " peroneal type " by Dr. H. Tooth, the " neuritic (neurotische) form " of Hoffmann. It is probably not dependent on the spiaal cord, and is considered more fully at a subsequent page. Complications. — Progressive muscular atrophy is occasionally accom- panied by the symptoms of some other degenerative disease of the spinal cord. The paralysis with spasm, already described, can scarcely be regarded as a complication : it is rather part of the disease, and its relation to the other symptoms will be considered when we discuss the pathology of the affection. In rare cases, muscular atroj^hy in the arms is accompanied by the symptoms of locomotor ataxy in the legs. By far the most frequent complication is bulbar paralysis, wealniess of the lips, tongue, pharynx, and often of the laryngeal muscles. It is the expression of a degenerative process in the medulla, similar to that which, in the spinal cord, causes the affection of the limbs. It may come on at any stage of the disease, may precede the spinal symptoms, or only come on when these have attained a con- siderable degree. In characters, the bulbar palsy may resemble perfectly that which occurs in isolated form, and wiU be described among the diseases of the brain. Frequently, however, there is but little paralysis of the tongue, even when swallowing and articulation are much impaired. There may also be slight interference with articu- lation when there is no marked bulbar palsy. A minor complication is the neuralgic pain, which, as already stated, is sometimes trouble- some in the early stage of cases that are due to cold. In several patients I have known headache to be frequent and severe throughout the course of the disease. General paralysis of the insane has been met with as an exceptional complication. f Course. — The malady, in most cases, is steadily progressive, as its name implies, but in the rate of its progress it varies in different cases, and iu the same case at different periods. It may, moreover, become stationary (sometimes as the result of treatment) at any period in its course, and when once actually arrested, it does not usually again become active. Unfortunately, the tendency to cessation is greatest in the later stages of the disease, when there is little except life to be preserved. Sometimes progress ceases at an earlier stage, and chiefly, I think, in those cases in which the atrophy is strictly symmetrical, and develops simultaneously, or almost simultaneously, on the two sides. Thus I have met with several cases in. which there was symmetrical wasting in the two hands, or in certain muscles of the two forearms or of the two upper arms, and in which the atrophy, * Cases, however, have been described more recently in which the upper limbs suffered first or simultaneously (Hoffmann, 'Deutsch. Zeitschr. f. Nervenheilk.,' 1891, i). t Tambroni, 'Riv. Sper. de Fren., &c.,' 1887, xiii, p. 184. 644 SPINAL COED. after attaining a considerable degree in its limited seat, had "become stationary and continued so. Occasionally some symptom (as weak* ness of the sphincters) may pass away, although the atrophy pro- gresses. When the progress at the commencement is rapid, it usually con- tinues rapid, until the disease has attained a wide extent, although the acute local onset mentioned below may be followed by slow extension. When it begins slowly, it is usually slow throughout. Although the disease sometimes commences in the ?8cond arm very soon after its onset, it more commonly makes some progress in its primary seat before beginning on the second side, and the interval that elapses varies with the rate of extension. It often happens that a year intervenes between the affection of the two arms, and I have known, in a very chronic case, the atrophy to slowly progress in one arm for seven years before it showed itself in the other. It is not common for the arms to be reduced to practical helplessness in less than two or three years, but the hands may become useless in as short a time as six months, while in one case the wasting, commencing at the shoulder, had invaded the whole arm in the course of a month. The shortest time in which I have known a patient to reach the last stage of the disease is nine months. With any rate of general progress, the otherwise uniform course of tne disease may be broken by the occurrence of almost sudden palsy in a certain group of muscles. Considerable loss of power, it may be absolute paralysis, comes on in a few days, or even in a few hours. It may occur at the onset of the affection. The extensors of the wrist and fingers are the muscles most commonly thus affected. The weak- ness is usually followed by a well-marked degenerative reaction in the muscles. I have seen several cases which began by such subacute or even acute paralysis of the extensor muscles, first in one arm and soon afterwards in the other ; the initial condition closely resembled the paralysis from lead poisoning, even to the escape of the supinator longus and ext. ossis met. pol. This cause was, however, excluded, and soon the muscles of the shoulder and back presented commencing slow progressive atrophy,' followed by wasting of the interossei until a typical state was reached. In another case, the quick loss of power was confined to the extensors in one arm, which were already weak and slightly wasted, most of the other muscles of the upper limbs having been long atrophied. When there is weakness of the legs without wasting, the onset of this may coincide with the atrophy of the arms, or raay succeed it at any interval. In one case five years elapsed, after the arms began to waste, before the legs became weak. It is very rare for the paraplegic weakness to occur first. The chief danger to life is from pulmonary maladies, rendered grave from the weakness of the muscles of respiration. The common com- plication of bulbar paralysis is another frequent cause of death, either by the interference with swallowing and nutrition, or by the laryngeal CHRONIC MUSCULAE ATROPHY. 545 paralysis. Less commonly, deatli results from bedsores and septicaemia, or from intercurrent maladies. Pathological Anatomy. — The wasting of the muscles is as evident after death as during life. They are reduced in size and pale in colour. Sometimes there is little in the tint of what remains to suggest muscular tissue. Parts of a muscle may he hardly dis- ti.;. U9, Pig. 150. Fibres of Wasted Muscles ik Pbogbessivb Mfsculab Ateopht. Fig. 147. — Narrowed fibres with nearly normal striation; others clear, containing a few fat globules, and a few faint transverse strisB and some longitudinal striation; lar^e globules of fat lie in the interstitial tissue in front of one narrowed fibre. Fig. 148. — Gr.inular degeneration : afibre with normal transverse striation presents also indications of longitudinal striation. Increase of nuclei of interstitial tissue. Fig. 149. — Two normal fibres and one presenting the clear homogeneous aspect, with a few fat globules and some faint striation. Fig. 150. — Several fibres similar to that of the last figure, with globules of fat between them. On the rigrht is a fibre which has undergone complete longitudinal stiiation, the normal strisB having disappeared, so that it resembles the adjacent interstitial fibrous tissue. Other fibres in the same muscle were in intermediate stages of degeneration, some transverse striation co-existing with the longitudinal striation. sponds to the wasting in the parts supplied by them. The posterioT roots are normal. The spinal cord is often softer than natural at the affected part, and the white substance of the lateral columns may be grey and translucent in aspect, especially in the cervical enlargement. Under the microscope morbid changes are seen in the anterior comua. CHRONIC MUSCULAE ATKOPHT. 547 and also in most cases, in tlie antero-lateral white columns. The change in the anterior comua corresponds in its intensity to the origin of the nerves to the most affected parts, and since the latter are usuaUj the arms, the disease is generally most intense in the Fig. 151. ^\ 1^ iWloI^ h \ 1 ' '^ Fig. 152. Pig. 151. — A normal anterior cornu for comparison with the next flgnre. Fig. 152. — Progressive muscular atrophy; anterior cornn, cervical region, rom drawinsrs bv Dr. H. R. Spencer.) ma. 152. — Jrrogressive muscular atrc (From drawings by Dr. H. R. Spencer.) cervical enlargement. In stained sections the grey matter of the horn is less deeply tinted than normal, but in some parts it may stain more deeply, especially in the circumference of the cornu and the processes of grey matter which project into the white column. Occasionally, 548 SPINAL CORD. larger areas hsuve a dense aspect and stain deeply, but the central part of the cornua is generally pale and wasted in aspect. Most of the large nerve-cells have disappeared ; many entirely, while others are re- presented only by small angular bodies. Not a single large cell may be seen in a section which, in a normal cord, would contain a consi- derable number. Frequently, how- ever, a few large cells can still be seen, but most of these have lost their processes and are more glo- bular than normal. The inter- stitial tissue is also changed. The nerve fibrillse waste with the cells, Fio. 153. — Progressive mnscular atrophy; degeneration of the anterior coniua and pyramidal tracts. A, medulla oblongatn, complete degeneration of the anterior pyramids, A P; B, at the upper part of the decussation of the pyramids ; D, the decussation of the degenerated fibres ; A P, the pyramids, still incomplete. C, cervical, JD, dorsal, E, lumbar sections. The degeneration of the anterior cornua 18 complete in C, but in E a few cells remain, for tlie most part without pro- cesses, in C and D tlie degeneration of both anterior and lateral pyramidal tracts is conspicuous; in E the anterior tract has ceased, and the lateral tract extends up to the surface of the cord, from which it is separated in C and D by the undegenerated direct cerebellar tract. In C and D the degeneration extends forwards in front of the lateral pyramidal tract, but gradually ceases. The fibres of the anterior commissure are also degenerated.* • In this case the arms were greatly wasted and fluccid; the legs were para- lysed, rigid, with moderate wasting. The muscles of the back were also atrophied. In the arms the weakness and wasting came on at the same time, in the right arm some time before the left. The shoulder muscles suffered first, but the atrophy quickly spread, and was ulti- mately extreme in the nmscles of the shoulders, forearms, and hands. The dis- ease ran a rapid course j death occurred two years after the gradual onset. CHRONIC MUSCULAR ATEOPHF. 549 and there is an increase of the small, angular, and stellate cells and other connective-tissue ele- ments. The larger vessels are dilated and surrounded by un- duly wide spaces, but there is no considerable distension of the capillaries. The comu as a whole is not usually changed either in size or shape. Similar alterations may be traced through the dorsal region. In the lumbar ■enlargement the grey matter may be normal, even when it is much altered in the cervical region ; but if the legs are wasted there are changes similar to those al- ready described. When the atrophy begins in the legs, the disease may be more intense in the lumbar than in the cervical enlargement ; but more often any degeneration that exists is slighter, and a larger number of normal or slightly changed cells Fig. 154. — Progressive muscular atro- phy. A, medulla oblongata; degene- ration of the anterior pyramids, A p. B, cervical, C, first dorsal, D, first lumbar, E, mid-lumbar sections. The nerve-cells have disappeared from the anterior cornua, except in E, in which a few remain. There is com- plete degeneration of the pyramidal tracts, anterior and lateral. The de- •cussation at the medulla was unequal in this case; of the left pyramid fewerfibres crossed tlian of the riglit, and hence the left anterior pyramidal tract is larger, while the right lateral tract is smaller than normal, and, moreover, has ceased at tlie middle of the lumbar enlargement, to which the left anterior tract extends.* * The patient was a man forty-eight years of age. The disease followed a severe exposure to cold. The wasting "^^^i J I / of the arms was extreme, and they were ^^'V 1 absolutely powerless. The legs were ^^^■^^>^»— -JsJl—— "''^^ much less wasted than the arms, but very weals, the loss of power being out of proportion to the wasting. 550 SPINAL COKU. can be seen. Sometimes certain groups of cells are little affected while others are mucli atrophied. The degeneration may involve to some extent the intermediate grey matter between the cornua, but here it ceases ; the posterior horn is always normal. There is distinct degeneration of the anterior root-fibres passing from the cornu through the anterior column, A few fibres may remain, but whole fasciculi appear to be replaced by fibrous tissue. There is also degeneration of the fibres of the anterior commissure, in consequence of which it stains much more deeply than normal, in the regions in which the grey matter is considerably diseased. In the white columns there is usually considerable, and often almost complete degeneration of the pyramidal tracts, anterior and lateral,* The area of sclerosis, resulting from the degeneration of the two tracts, varies in extent according to the size of the anterior tract, and to the distance which it extends down the cord. In Fig, 154 this is illustrated in an unusual manner, in consequence of an inequality in the decussation of the pyramids at the medulla, fewer fibres of the left pyramid having crossed than of the right, so that the left half of the cord contains more than its proper share of the fibres, and the anterior tract extends into the lumbar region even further than does the lateral tract. Where the direct cerebellar tract exists, this, always unaffected, limits the sclerosis of the lateral tract on the outer side. On the inner side, the " lateral limiting layer " (see p. 221) is usually much less degenerated than the pyramidal tract, and intervenes be- tween the latter and the grey matter ; but this layer suffers in some degree, perhaps by the affection of outlying pyramidal fibres con- tained in it. The sclerosis does not usually cease at the anterior extremity of the pyramidal tract, but extends forward in the " mixed zone" of the lateral column, lessening in intensity, and ceasing usually opposite the outer part of the anterior cornu. It is here most intense close to the grey substance, and ceases before it reaches the surfare of the cord, the antero-lateral ascending tract being unaffected. This sclerosis may be due to the degeneration of the short vertical fibres that pass between adjacent regions of the anterior cornu, and which share the degeneration of the nerve-cells. Occasionally it extends, in slighter degree, into the anterior columns. The posterior columns are always free from definite degeneration, but there may be some general increase of connective tissue throughout the whole cord. The degeneration of the pyramidal tracts is usually * I have not yet met with a single ease of progressive muscular atrophy in which the pyramidal tracts were unaffected. Such cases are extremely rare. One has been published by Stiiimpell ('Zenker's Zeitsch.,' 1887, and 'Neur. Centralbl.,' 1888, p. 139) which was ciiaracterised by the general wasting of the arm, a very slow course, and the absence of leg symptoms. The spinal nerve-cells and motor nerves were degenerated. Other cases have been described by Villiers ('Journ.med.de Bruxelles,' 1897) and by Beevor in a communication to the Neurological Society of London in 1896. CHRONIO MUSCULAR ATROPHY. 551 considerable in degree ; often most of their fibres seem to have perished. If it is incomplete in the cervical region, it may be slight in the lower part of the cord, the degenerated fibres being chiefly those that end in the cervical enlargement and dorsal region. "When the sclerosis is intense it is not confined to the cord ; it can be traced up through the decussation (Fig. 153, b) and through the medulla oblongata, in which, as Figs. 153 and 154 show, the whole of both pyramids may be degene- rated, so that they stain deeply, and no nerve-fibres can be dis- tinguished in them. The degeneration of the pyramids has been found in several cases to extend through the pons and crus to the internal capsule, and even through the white substance to the cortes. Above the capsule, however, the pyramidal fibres are so mingled with others that their degeneration is no longer recognisable by the deeper staining of a definite tract ; but it has been detected by the presence of abundant products of degeneration in the path of the fibres. In the motor cortex the large ganglion-cells have been found fewer than normal and distinctly degenerated, many having lost their processes ; and, in the interstitial tissue, the spider-cells and other connective- tissue elements are increased in number.* But the degeneration of the pyramidal tracts has also been found to cease at the crus f and at the decussation. J In cases in which the symptoms of bulbar paralysis were present during life, the motor nuclei of the medulla have presented changes corresponding to those of the grey matter of the spinal cord, with a similar degeneration of the nerve-cells. In other instances the degeneration of these nuclei has been slight, but in such cases the degeneration of the pyramids has been intense, and doubtless involved the fibres connecting these nuclei with the cortex of the brain. The sympathetic nerves and ganglia, when examined, have been found normal, or have only presented such changes as are common apart from symptoms of disease of the nervous system. Pathology. — The theories, according to which the disease was regarded as primarily one of the muscles or of the sympathetic nerves, have now only an historical interest. The constancy of the changes in the ganglion-cells of the spinal cord, the degeneration of the motor root-fibres, and the analogous effects of acute lesions of the anterior cornua, leave no doubt of the relation of the muscular wasting to the disease of the grey matter, and essentially to that of the ganglion-cells, and the fibres proceeding from them. The slowness of the change causes the impairment of the nutrition of the muscular fibres to pro- ceed pari passu with that of the nerve-elements, and the interference with motor conduction to be proportioned to both. We are thus able to understand the condition of electrical excitability, and its slow * Koschewnikoff, 'Arcliives de Neurologie,' 1883, No. 18; aud ' Ceiitralbl. f. Nerveukr.,' 1885, p. 409 ; Marie, ' Neiir. Ceutialbl.,* 1884, p. 61. t Rovighi and Melotti, loc. cit.; Dornbluth, 'Neur. Centialbl.,' 1889, p. 377. j Moeli, 'Arch. f. Psych.,* x, 718. 552 SPINAL COED, failure, as nerve and muscle degenerate together. It is only wlien tlie slow degeneration is varied by a more acute process of destruction of cells and more rapid degeneration of fibres that the muscular tissue ia for a long time less damaged tban the nerve-fibres, and presents paralysis in excess of the wasting, with a voltaic irritability in excess of the faradic irritability of the nerve-endings (p. 30). Thus the essential lesion of the disease is a slow decay of the lower segment of the motor path, the segment which consists of the ganglion- cells and their prolongations in the axis-cylinders of the nerve-fibres (seep. 213). To this the conspicuous symptom, the muscular wasting, is secondary. It is perhaps better thought of as a degeneration of the whole segment than as simply a lesion of the ganglion-cells, although the latter being the element on which the nutrition of the segment depends, the two views are merely different modes of stating the same fact.* But the disease is rarely limited to the lower segment of the motor path. The cases mentioned in the note on p. 550 are an example of such rare limitation — an " exception that proves the rule."t We have seen that the pyramidal tracts are commonly degenerated, and it is probable that the degeneration often extends throughout their entire extent, and involves the motor cells of the cortex.J Thus the upper segment is often degenerated as well as the lower segment. In the presence of that complete degeneration of the lower segment which causes the atonic atrophy of the muscles, the degeneration of the upper segment can cause no symptoms. The loss of power that it would produce is also caused by the degeneration of the lower segment, and the latter abolishes the myotatic irritability, excess of which is the characteristic indication of disease of the upper segment. Hence the degeneration of the upper segment of the motor path for the muscles that present the atonic atrophy cannot as a rule be recog- nised during life, for it cannot produce its characteristic symptoms. What is the relation between the degeneration of the two segments, between the lateral sclerosis and the affection of the ganglion-cells ? We cannot assume (as some have been inclined to do) that the affection of the upper segment is secondary to that of the lower, because a * In a few anomalous cases, degeneration of the motor cells of the cord has been met with when no degeneration could be detected in the peripheral mixed nerves (see Kronthal, 'Neur. Centralbl.,' 1891, p. 133). The interpretation of these cases is at present uncertain. Possibly complete disappearance of some fibres left the rest apparently normal, although the skill of the investigators renders this explana- tion difficult to accept. Many more observations, however, are needed to justify a modification of current views. t Moreover the fact that these cases may not be primarily spinal must be borne in mind. X At the same time we have seen (p. 255) that the nutritional stability of nerve- fibres is less in their lower than in their upper parts, and that their isolated degene- ration may be greatest in the lower parts. That tliis may sometimes also be the case in these pyramidal fibres is suggested by the fact already stated that the degeneration may extend no higher than the decussation of the crura cerebri. CHRONIC MUSCULAR ATROPHY. 553 primary lesion of the grey matter, sucli as occurs in polio-myelitis, does not cause ascending degeneration of the related pyramidal fibres. Moreover, even a complete interruption of the pyramidal tracts is followed by no degeneration of their upper parts. Hence the iatense degeneration met with in progressive muscular atrophy cannot be regarded as secondary. Neither, when there is atonic atrophy, can we consider the affection of the upper segment to be the primary lesion, and to be the cause of that in the lower. In the seat of slight atrophy there are, as a rtde, no indications of the preceding degeneration of the upper segment, which would certainly exist if this lesion were 1 he primary change. Moreover degeneration of the upper segment d()es not necessarily cause any degeneration of the lower. It is a matter of €very-day observation that intense degeneration of the termination of the upper segment may occur, from dorsal myelitis, for instance, with- out any considerable wasting of the legs, and such degeneration has never been known to excite the complete degeneration of the lower segment which causes atonic atrophy. Hence the only adequate explanation of the facts is that the degeneration of the upper and lower segments is simultaneous, or if not simultaneous, at least so far independent that neither is the cause or consequence of the other ; both are the results of the same tendency to degeneration of the motor path.* Atonic muscular atrophy is thus, at least in many ■cases, the visible expression of a tendency to decay of the whole motor path from the cortex of the brain to the muscles. The weakness of some parts, as the legs, with excessive myotatic irritabihty, often going on to spasm, is explained by the degeneration of the pyramidal fibres for the legs, the lower segment being unaffected. It is easy to understand that the affection of the upper segment, and escape of the lower, or the affection of both, may vary much in relative extent, and give rise to ^he multiform varieties already mentioned. In such a case the nerve-cells for the part thus paralysed are normal. This weakness of the legs usually succeeds the wasting in the arms, and in most cases in which spastic paraplegia is followed by atrophy in the arms, the latter have not shared the spastic palsy. When this condition is associated with sUght wasting of the legs, without con- siderable change in electrical irritability, the condition exists that we have more than once considered, in which we must assume that the motor nerve-cells of the cord, while structurally intact, undergo sKght •changes in nutrition. In this condition there are many nerve-cells of nonnal appearance in the grey matter ; the alterations in nutrition are too slight to cause changes in aspect, or if there are such changes we have not yet learned to detect them. They are perhaps results of the degenerative changes in the termination of the upper segment ; when such degeneration is secondary to a focal lesion of the cord or brain, the changes in nutrition of the cells seldom attain such a degree as to * See case published by Mott Brain,' 1895. 554 SPINAL COliD. arrest tlie myotatic irritability, or to cause wasting such as attends the destruction of these cells. In some cases, however, the muscular wasting may be great, although the increase of myotatic irritability persists. In these cases, as w© have seen, there is considerable rigidity of the muscles throughout the whole course of their wasting, the condition that we have termed "tonic atrophy," In such a condition it is common to find that many nerve-cells have disappeared or are very small, but others remain normal or slightly changed in aspect. Apparently, in addition to the degeneration of the upper segment and to the nutritional changes just mentioned, we have then a considerable degeneration of many, but not destruction of all, the elements of the lower segment. We cannot regard this as simply secondary to the degeneration of the upper segment, for the reasons already given. It must be the expression of a distinct pathological tendency similar to that which elsewhere causes the atonic atrophy and total wasting, but slighter in extent and later in time — insufficient to prevent the less affected cells from causing rigidity under the influence of the degeneratioa of the upper segment. It is doubtful whether the tonic atrophy ever goes on to atonic atrophy. Theoretically conceivable, it is certain that if it ever occurs it is extremely rare. Nor does it seem that atonic atrophy ever gives place to tonic atrophy with excessive myotatic irritability. The rigidity of tonic atrophy is due to the degeneration of the upper segment, but the effect is not produced if the lower segment is already the seat of such extensive degenerative changes as abolish myotatic irritability. The pyramidal fibres for the parts that are the seat of atonic atrophy are constantly found degenerated, although the muscles have been flaccid to the last. In the rare cases (mentioned on p. 540) in which muscles with atonic atrophy become rigid towards the end of the process, it is probable, as the tenderness suggests, that the rigidity is idiopathic, due to the changes in the muscles, and is not dependent on the ceotral nervous system. It may be the result of the increase in the interstitial connective tissue, and the longitudinal division and fibrillation by which the muscular fasciculi come to resemble bundles of connective-tissue fibres. It is also possible that similar idiopathic muscular changes may ultimately, in tonic atrophy, maintain and increase the rigidity that is primarily dependent upon the spinal cord. It has been mentioned that the cases in which the legs present the simple palsy and spasm, or the tonic atrophy, which indicate degeneration of the pyramida.1 tracts, have been separated by Charcot, and termed " amyotrophic lateral sclerosis," the separation being based on the assumption that in such cases the primary lesion is the degene- ration of the pyramidal tracts, and that the affection of the grey matter is secondary or " deuteropathic," even where the atrophy is atonic. We have seen also that this assumption is unwarranted so far as the atonic atrophy is concerned. It is probable that the pyramidal CHRONIC MUSCULAR ATROPHY. 556 tracts are degenerated, if not constantly, at any rate in such a very large propoi-tion of the cases of progressive muscular atrophy, that Charcot's distinction is, in effect, giving a new name to an old disease, and that the sequence is not that indicated by the name. "Whether there are indications of lateral sclerosis or not depends on the circumstance whether the degeneration of the pyramidal fibres is or is not more extensive than the complete degeneration of the nerve-cells that causes atonic atrophy. If the latter is universal the pyramidal tracts may be totally degenerated, and yet there may be none of the characteristic indications of such degeneration. On the other hand, both arms and legs may be the seat of the spastic paralysis that indicates pyramidal degeneration, and atonic atrophy may be limited to a few muscles of the hands. Between these we have every grada- tion, in degree and distribution, of atonic atrophy, spastic paralysis, and tonic wasting. The process in the grey matter has been regarded by some as a chronic inflammation. The occasional rapid increase in the symptoms may be thought to be justification for this view ; but the process in genera] is at the degenerative extremity of the series of nerve lesions. The principle involved in this question has been already discussed, and we have seen that, whatever be the nature of the primary process, we must recognise secondary tissue changes of independent energy, and that a distinct process of inflammation may occasionally form part of these (see p. 443). The significance of the occurrence of inflamma- tion may therefore easily be overrated, so far as concerns the question of the process, and the tissue-elements in which the disease begins. Diagnosis. — The simultaneous and gradual onset of weakaess and wasting, the slow but progressive increase and extension of the symptoms, render the diagnosis of the developed malady simple and easy. At the onset, when only a single muscle or group of muscles is affected, the question arises whether the atrophy is local or is the commencement of a wider affection. Local atrophy is said sometimes to occur from great over-use of a muscle, especially one of the small muscles of the hand ; but such a cause is extremely rare, and only to be suspected on the clearest indications. As a rule, the local atrophy from which the affection has to be dis- tinguished is that due to disease of the nerves. The wasting from disease of single nerves or at a plexus (as the brachial) is sufficiently distinguished by its limitation, coupled with its rapid onset and associated sensory symptoms. Much more difficult is the distinction of some forms of multiple neuritis. The difficulty presents itself chiefly in two forms : t^l) when the spinal affection begins as sub- acute atrophic palsy (see p. 544); (2) when neuritis affects chiefly motor branches, as in the arms in lead poisoning, or in the legs in alcoholism, &c. In the first case it is necessary to wait for signs of slower wasting in other parts than those first affected before a diagnosis can be made. In the second, a careful search will generaUj 556 SriNAL CORD. reveal other symptoms of neuritis, and a known canse is usually obtrusive. In pachymeningitis of the cervical region, with considerable damage to the nerve-roots, the wasting in the arms may resemble that of progressive muscular atrophy, and there is often weakness with rigidity in the legs ; but the wasting is less chronic in onset, and is always accompanied by distinctive sensory symptoms, — by acute pains, and usually by anaesthesia, irregular in distribution. The same dis- tinctions suffice for the diagnosis in diseases of the ne; ve-roots of the Cauda equina, as by a tumour. This may cause slow wasting in the legs, but there is always severe pain and loss of sensibility. Chronic disseminated myelitis may cause wide-spread muscular atrophy, but is distinguished by the presence of symptoms of irregular damage to other structures in the cord. The diagnosis from syringomyelia will be considered in the account of that disease. Erom primary muscular atrophy, " idiopathic atrophy," a variety of " muscular dystrophy," as it has been termed, the diagnosis is some- times easy, sometimes very difficult. It is easy in the pseudo-hyper- trophic form, and often also in the atrophic variety (the cases in whieh n.0 muscles are large), on account of its characteristic distribution, its course, the age at which it begins, and the tendency to affect many members of a family, and males more than females — features that will be presently described. Whenever several cases of muscular atrophy occur in a family, or during childhood or youth, the probability is great that they are idiopathic and not spinal. Indeed, the idiopathic form is to be suspected whenever muscular atrophy begins under twenty, unless there are distinctive spinal symptoms. But cases are sometimes met with in which idiopathic atrophy begins in adult life, and the distinction of such cases may be very difficult, and will be better understood after a perusal of the account of that disease. Peognosis. — The progressive character of the malady renders the prognosis, in every case, grave and uncertain. The chief guide is the observed tendency of the morbid process, both the fact of its actual advance and the energy it manifests. At the same time there is a possibility of arrest, greater in middle life than in old age. Some in- crease of atrophy in the parts already affected may occur for a short time after the process in the cord has ceased to spread — the muscular wasting going on until it corresponds to the changes in the nerves that have already taken place. The prospect of arrest seems to be greater in the cases in which the wasting is strictly symmetrical and nearly simultaneous on the two sides than in those in which it is irregular, and attacks the second side when it has attained a marked degree in the first. Spontaneous cessation unfortunately seldom tends to occur imtil an advanced stage is reached ; but, as the result of treatment, arrest may take place at any stage. The danger to life is chiefly pi'o- portioned to the interference with the muscles of respiration, and to the indications of implication of the medulla. Bulbar symptoms CHRONIC MUSCULAR ATROPHY. 557 increase the gravity of tlie prognosis, especially when definite weak- ness can be recognised. Slight vague difl&culty in articulation may remain stationary for years, and does not necessarily render the prognosis worse, especially if the atrophy elsewhere does not increase rapidly. If the malady ceases to advance, the prospect of any recovery depends on the rate at which the disease has progressed. Recent rapid loss of power may be to some extent recovered from, especially when the muscles present the degenerative reaction. Wasting that has existed for six months will probably persist unchanged. In a typical chronic case there is little hope of any actual recovery of tissue or power. The effects depend on a slow destruction of nerve-elements, the renewal of which seems to be impossible. Treatment. — The first important element is to secure favorable con- ditions of life, and to maintain the general health in as perfect a state as possible. Fresh air and gentle exercise are important, but all fatiguing exertion should be avoided, and likewise all mental strain. When the patient becomes helpless, great care is necessary. Bedsores in this disease mean inattention, and may always be avoided. Only one method of treatment has, in my own experience, shown itself capable of arresting the disease, not indeed in aU, but in more than half the cases in which it has been employed.* It is the admin- istration of strychnia by hypodermic injection. In seven almost con- secutive cases, in middle life, this treatment has been followed by arrest within a month of its commencement, and the arrest has been permanent in all the cases but one. In the senile cases the treatment has failed, but in most of them the disease was in an advanced stage, and the lumbar cord had begun to suffer. In some of the cases in which the result was prompt and distinct, strychnia given by the mouth had failed. It is conceivable that the different result is due to the fact that the agent is brought into more rapid contact with the nerve-elements, perhaps in purer form. Its action may possess greater momentum, as it were, and may thus exert an influence on the nutrition of the nerve-elements much more considerable than when it is slowly absorbed from the alimentary canal. One injection daily has been given, at any convenient place. The nitrate is the most convenient salt, one fiftieth of a grain at first, quickly increased to one twentieth or one fifteenth. The injections need to be continued for months. When the malady is apparently arrested, it is well to intermit the injections for one week in three or four. Other nervine tonics seldom exert a distinct influence, but those that are useful in other degenera- tive diseases, as tabes, such as arsenic, may be given by the mouth at the same time as the injections are employed. In a malady so grave * At first I regarded the apparent result with doubt, but careful and repeated observations have made it impossible to consider the arrest of the disease as other than the direct effect of the treatment. It may be asked. Why should not a larger dose by the mouth be equally effective P It does not seem to be, is the only answer that can be given. 558 SPINAL CORD. it is desirable to neglect nothing that may possibly exert a beneficial influence. Local treatment of the muscles has very little influence on the wasting, as may, indeed, be expected from its nature. The most sedulous and skilful use of electricity, voltaic or faradic, fails, as a rule, to produce alone any effect on the course of the disease. If the malady is progressing at the same rate in each arm, and the muscles of one arm are regularly treated with electricity, while those in the other arm are left alone, no difference can be detected in the rate of wasting on the two sides. It is possible, nevertheless, that electricity some- times does a little good. In cases in which a rapid loss of power has occurred, and weakness is out of proportion to the wasting, some re- covery is possible, and there is no doubt that the excitability of the muscular tissue is maintained for a longer time by galvanism, although the bulk of the muscle may not be influenced. In other cases all that can be said is that the influence of electricity, properly applied, is in the right direction. Moreover the disease is one of those in which patients find it hard to believe that electricity cannot help them, and the probability is that their conviction will be fostered by some medical adviser. It is one of the diseases in which unjustifiable assertions are too often made that early electrical treatment would have been suc- cessful. It may be weU, therefore, if only to satisfy the patient that nothing has been left untried, that a careful course of electrical treatment should be adopted. Faradism may be used if the muscles are sensitive to it, but i£ they present any greater irritability to voltaism it is better to use this. It is immaterial whether the appli- cation be confined to the muscles or whether one electrode be placed over the affected part of the spinal cord. The latter method has no disadvantages, but my own observations have failed to confirm the confident statements sometimes made regarding its superiority. It is very important that the current strength employed should be moderate. Strong applications often cause much subsequent paia, and even increased disability, and should be carefully avoided. I have known a rapid increase of weakness follow a strong application in a way that convinced the patient, at least, that the two were connected. Rubbing and massage of the muscles have been frequently employed, and of this treatment also it may be said that its influence is in the rio-ht direction, although usually inappreciable so far as the muscular atrophy is concerned. Combined with passive movement, the influence of rubbing in preventing and diminishing deformities is more distinct. No special bath treatment is of service. When the disease occurs in the subjects of syphilis, specific treatment invariably fails, and I have even known the progress of the disease to be distinctly accelerated by an energetic course of treatment both with iodide and with mercury. It is important that all treatment should be pursued in moderation, and that its effects shoxdd be carefully watched. AETHEITIO MUSCOLAE ATEOPHT. 659 Aetheitic Muscttlae Ateopht. Articular inflammation is almost invariably attended "witli rapid wasting of the muscles that move the joint. This occurs equally, whatever be the cause of the inflammation, and whether this is spontaneous or traumatic. It attends chronic as well as acute inflam- mations, and occurs in animals if joint inflammation is produced in them.* The muscles that waste are chiefly those which extend the affected joint. The atrophy is well seen in the muscles in front of the thigh when the knee is inflamed. If the ankle is affected, the calf muscles chiefly waste ; if the hip, the glutei ; if the wrist, the extensor muscles of the forearm ; the triceps when the elbow is affected ; the deltoid when the shoulder- joint is inflamed. In rheumatoid arthritis of the finger- joints such wasting is usually very conspicuous in the interossei, and especially in the abductor indicis. The atrophy, however, sometimes involves the flexors as well as the extensors, and rarely muscles of the limb that are near but do not move the affected joint. In very rare cases all the muscles of a limb have presented some wasting. Cases in which the atrophy is unusual in distribution, and especially when it is on the distal side of the affected joint, must be regarded with some suspicion, because inflammation may have spread from the joint to a nerve, and distant wasting may have been thus produced. It is said that there is sometimes, at the onset, a considerable weakening of the muscle, interfering with movement more than can be accounted for by the pain in the joint which movement causes, and that such initial palsy is transient (Yaltat, Duchenne). But the pain, by its inhibitory influence, usually obscures such palsy, which is indeed con- fessedly rare. The atrophy, on the other hand, may be regarded as almost con- stant. If the onset of the joint affection is acute, the wasting occurs rapidly; in a week or ten days a difference in the circumference of the limb may be detected by measurement. However long the affected muscle may be, the wasting involves the whole length of it, and not merely the part in the neighbourhood of the diseased joint. The degree varies ; usually moderate, and sometimes slight, it is occa- sionally considerable, so that the femur may be readily felt when the quadriceps femoris is the seat of the wasting ; or the head of the humerus may be distinct, and the acromion prominent, if the deltoid is affected. Although the whole length of the affected muscle is always involved, if the muscle is a wide and compound one some parts may suffer chiefly. Thus in the thigh all parts of the extensor • Valtafc, 'Archives generales,* 1877, tome xxx. pp. 159 and 321. The subject has been discussed by Vulpian (•Le9ons sur I'App. Vaso-moteur,' 1875, t. ii) and by Paget (' Lancet,* 1873, vol. ii, p. 727, in a lecture republished in • Clinical Lectures and Essa^ s,' 1875, p. 208). 560 SPINAL COED. may waste equally, or the rectus or vastus internus may suffer more tlian the other parts. Tho wasting increases during two or three weeks, then becomes stationary, but continues as long as the joint disease lasts. When the joint has recovered, the muscles in most 3ases slowly regain their normal size. Occasionally, especially when the arthritis has lasted a long time, the wasting may continue for months or years after the joint disease is at an end. The electrical irritability of the atrophied muscles may be normal, but is often slightly lowered, equally to faradism and voltaism. The change is trifling, to be recognised only by comparison with the other side. There is generally a distinct and sometimes a considerable local increase in myotatic irritability; the knee-jerk is excessive if the thigh muscles are affected, and a rectus- clonus can sometimes be obtained. A foot-clonus may be elicited when the ankle-joint is affected. Occasionally the increased irritability extends beyond the region of atrophy, so that, for instance, a foot-clonus may be obtained when the knee-joint and thigh muscles are affected, although there is no wasting below the knee. As an example of this, which illustrates also the occasional persistence of the atrophy, may be mentioned the case of a young man who jumped over a hoarding and twisted his left leg in doing so. He felt immediately severe pain in the knee, the joint quickly swelled, and became the seat of an acute inflammation which lasted for several weeks, and then slowly subsided. During the inflammation the thigh wasted. I saw him two years after the onset, and there was still considerable wasting, involving the whole of the extensor of the knee. The minimum circumference of the left thigh above the knee was three quarters of an inch less than that of the right, although there was no difference between the two legs below the knee. There was a slight diminution in f aradic and voltaic irritability in the affected muscles. The knee-jerk was much more considerable on the left than on the right side, and there was well-marked foot- clonus in the left leg, but none in the right. A year and a half later the symptoms were unchanged. Very rarely some contracture occurs in the opponents of the atrophied muscles. Sensory symptoms are as a rule absent, but there may be slight tingling in the skin during the acute stage ; it is said that areas of anaesthesia sometimes develop, but probably in such cases, inflammation has extended to a nerve iu the vicinity of the joiat. Pathologt. — Few facts have been ascertained regarding the con- dition in man. In one case, carefully investigated, the only change was iu the muscles, and consisted merely in a narrowing of the fibres, one half of which were below the normal average, while no less than 84 per cent, fell short of a standard which, in health, only 21 per cent, failed to reach.* A few presented longitudinal striation (as in Fig. 150), and some of noi-mal width were unduly tortuous; other- wise their aspect was normal. The sheath nuclei were proliferated in * Darkschewitsch, ' Neur. Cent.,' 1891, p. 353. AETHRITIC MUSCULAR ATEOPHT. • 561 places, and apart from this change tlie intermediate substance pre- sented local increase in quaatity, especially where the fibres were narrower than normal. This observation agrees with those that have been made on animals, in which the condition has been produced, and in them, moreover, the motor nerves have been fotmd normal (Yaltat).* Indications of inflammation have been fonnd in the joint nerves.t as might, indeed, be expected, whatever the mechanism of the atrophy. Visible changes in the spinal cord have never been discovered, but this does not exclude nutritional changes. We may, therefore, exclude from the possible causes, all forms of motor neuritis, both simultaneous, due to the cause of the joint inflammation, and consecutive, communicated to the adjacent nerve from the joint. The latter (a secondary extension of inflammation to the nerve) would manifestly not explain the affection of the whole of a muscle on the proximal side of the affected joint — as, for instance, atrophy of the whole extensor in arthritis of the knee — although the extension does occur, and must be recognised as an occasional event. ij: We must also recognise the possibility of a simul- taneous neuritis, with acute changes in the nerve-fibres, manifested by the reaction of degeneration in the muscles. The event is, how- ever, exceptional. It is certainly separable and to be separated from the common arthritic atrophy ; but it is not easy to keep apart the two varieties of neuritis — the simultaneous and the consecutive — when a case is seen only long after the onset, because a neuritis that arises by extension may travel along the nerve and present an ulti- mate distribution quite different from that which it possessed at the onset. For ordinary arthritic atrophies we must seek some other explana- tion. The nature of their cause long ago suggested to Paget a " reflex influence " on the muscles as the probable mechanism, and Yulpian and Charcot have suggested a similar hypothesis, assuming a derange- ment of the nutrition and influence of the motor cells of the cord, to be determined by the morbid impulses from the joint nerves, and to determine the alterations in the muscles. The theory receives impor- tant support from the fact that the wasting of the muscles is pre- vented by previous division of the posterior spinal roots (Eaymond), which amounts, indeed, to an indirect demonstration of the fact that % reflex process § underlies the phenomena. It' is doubtful whether we can go much further than this. By preceding hemisection of the cord it is increased on the side of the operation ; but the conditions • Valtat, 'De I'Atropliie Muse, &c.,' Paris, 1877. See also Deroche, *]Stude cliu. et exp.,' Paris, 1890. t See Duplay and Cazin, 'Arch, gen.,' January, 1891. X E.g. to the ulnar, in rheumatoid arthritis of the hand (Bury, *Med. Chron.,* 1888, p. 182). See on this subject A. E. Garrod, *Med.-Chir. Trans.,' Ixxi, 265 ; also Pitres and Vaillard, ' Rev. de Med.,' 1887, No. 6. § R:iymond, * Kev. de Med.,' 1890, 374. VOL. I. 36 562 SPINAL COED. are here more complex, and tlie demonstration of tlie reflex relation less simple, than in the result of division of the roots. The increased knee-jerk, &c., that attend the wasting, and the curious fact that arthritis may set up a degeneration of the spinal cord, apparently beginning in the termination of the pyramidal fibres (see p. 493), should be kept in mind. They are certainly significant, and suggest that the influence from the joint nerves acts on the " con- trolhng structure " of the muscle-reflex centre (see p. 240) ; but more facts are needed before a valid hypothesis can be framed. Diagnosis. — The moderate degree of the wasting, with correspond- ing change in electrical reactions, coupled with the wide extent of the alteration, embracing the whole of the muscles involved, constitute a distinctive characteristic — distinctive, at least, when taken in con- nection with the preceding joint affection which is the cause of the atrophy. A primary neuritis, causing secondary arthritic adhesions, has its own features — ^their wider range, so far as function is concerned, and especially their limitation to nerve distribution. Hardly any other malady is likely to be confused with it, except some graver disease, while still in an early sta'--^ ; but such an affection can only be dis- tinguished by waiting until the nature of the malady has had time to show itself. Peognosis. — When the inflammation of the joint is brief in dura- tion, recovery of the muscles may be anticipated with confidence. In children, even after prolonged joint disease, the muscles usually regain their normal bulk. In adults the wasting often lasts for a long time after the joint is well, and a cautious prognosis shoidd be given if the arthritis has lasted long. Even if sHght wasting is persistent, normal power is usually recovered ; but, as the case mentioned above shows, the symptoms sometimes continue for years. The prognosis should be especially cautious where there is a marked increase in myotatic irritability, or if the atrophy shows a disposition to involve other muscles of the limb than those concerned in moving the affected joint. Treatment. — The chief treatment is local, — electrical stimulation of the muscles, and gentle rubbing. It is doubtful whether drugs have any influence on the condition, but small doses of strychnia may be given, or added to whatever agent is given for the joint affection. As long as the joint is inflamed, treatment rarely causes any increase in the bulk of the muscle. It is of great importance to secure the early recovery of the joint, and to avoid aU influences that cause pain in it, since, as we have seen, it is apparently through the sensory nerves that the joint affection exerts its injurious influence. When the arthritis has ended, the muscles usually recover slowly without assistance, but it is probable that the local treatment accelerates the process. The form of electricity is of little consequence; either faradism or voltaism may be employed, but snould only be used in suf&cient strength to cause gentle contraction. The muscles act MUSCULAR DYSTROPHIES. 563 readily to faradism, and a mild faradic current is, as a rule, tlie best to employ. All painful stimulation of the sensory nerves should be avoided. MUSCTJLAB AtEOPHY PROM OvEE-r*!!!. Muscles that are much used sometimes waste. The effect is seen most frequently in the small muscles of the hand, especially in persons of weakly constitution, who use these muscles unduly. Thus a young lady devoted many hoiurs a day to " illuminating," during several years, and then some muscles of the thenar emiuenco began to waste, and became considerably atrophied. Such wasting is scarcely ever met with in the larger muscles, but has been observed in the biceps, consecutive to hypertrophy, in Sheffield smiths (Frank- Smith;. The electric irritability is gradually lowered in this local wasting, equally to both currents, as it is in progressive muscular atrophy. We do not know whether this wasting from over- use is purely local, or whether the related ganglion-cells of the spinal cord fail first, and the muscular wasting is secondary to their atrophy. Gull said many years ago, " it is as reasonable to infer a lesion of the grey matter from overwork as of the muscles."* The wasting often persists when the over-use of the muscles is discontinued. Hyper- trophy from over-use does not usually give place to atrophy. These two facts are somewhat in favour of the view that the lesion is primarily of the nerve-cells. The wasting in these cases shows no tendency to extension beyond its original limits. The treatment is, first, the cessation from the excessive exertion of the muscles; secondly, the improvement of the general health, and the adminis- tration of nerve tonics, especially of strychnine ; and thirdly, the gentle electrical stimulation of the muscles by either faradism or voltaism. THE MUSCULAR DTSTROPHIES. Idiopathic atrophy, which is primarily muscular, although it is not one of the diseases of the nervous system, is commonly described with them, because it frequently presents so close a resemblance to the spinal atrophy just described as to be distinguished with some diffi- culty. Moreover, even the varieties that do not present this close resemblance were for a time, and indeed until lately, believed to be of central nature, to depend on the spinal cord, and to be rightly included among its diseases. Hence the custom of thus describing them has become established, and has now to be followed, although we know that it is based on a mistaken theory. At the same time, not only • ' Guy's Hosp. Reports,' 1862, p. 246. b(^i SPINAL CORD. has tlie raethod the advantage of convenience, but it has also some measure of scientific justification. The muscles are more closely allied to the nerves than to any other structures, as regards both physiological properties and pathological susceptibility, and it ia doubtful whether any other association would better befit these diseases. The idiopathic myopathies have received much attention during the last few years, and many new facts have been ascertained with regard to the different varieties and their relations to each other. The treatise by Erb* has had the effect of giving unity and cohesion to w^hat was formerly a collection of disconnected types, and has con- clusively demonstrated the essential identity of the different varieties hitherto described. The so-called pseudo-hypertrophic variety of muscular affection has been recognised under this name ever since its graphic description by Duchenne.f The features of this were muscular weakaess associated with enlargement of muscles, sometimes a few, sometimes many. He also described in the same work 'I another form of paralysis which he supposed to be similar in its etiology to the progressive muscular atrophy of adults, and which he named " atrophic musculaire progressive de I'enfance." This was characterised by wasting of the muscles of the face as well as of the limbs, and also by its tendency to affect more than one member of a family. Leyden in 1875 § proposed to separate the hereditary forms of muscular atrophy from those of the Aran-Duchenne type. He pointed out that the hereditary form tends to commence in early life, to affect several members of the same family, especially the males, and he directed attention to the resemblance between the hereditary form and the pseudo-hypertrophic of Duchenne. In 1879 || Gowers in a clinical lecture gave a full description, from numerous clinical observations, of pseudo-hy3)ertrophic paralysis, and also set out all that was known of its pathological anatomy, and in this lecture clearly recognised that hypertrophy and atrophy may be combined in different proportions, and that there are cases that connect the two extremes — in some enlargement of many muscles, in others wasting in all. Such a view affords a glimpse of the group which Erb ^ afterwards clearly outlined under the name of the " juvenile form of progressive muscular atrophy." Prom a consideration of the characters and histories of these cases Erb concluded that the three varieties — ^the juvenile form, the here- ditary form of Leyden, and pseudo-hypertrophic paralysis — were all varieties of one condition, for which he proposed the designation * * Dystrophia mascnlaris progressiva,' Leipzig, 1891. + ' Electrisation localis^,' 3rd edit., p. 595. X Ibid., p. 518. § ' Klinik der Ruck. Krank.,* ii, p. 525. || ' Lancet,' 1879. % « Deutsch. Arch. f. klin. Med./ Bd. xxxiv, 8. 467. MUSCULAE DYSTfiOPHIES. 565 *' dystrophia muscularis progressiva." The next important step in tlie development of our knowledge took j)lace in 18P5, when Landouzy and Dejerine published* an exhaustive paper on what they named " Myopathic Atrophique." It dealt with observations of an exceed- ingly intevest:jig group, the essential characteristics of which were wide-spread muscular atrophy commencing in the face, and without hypertrophy. These cases were really identical with tho-e described by Duchenne as "atrophie musculaire progressive de I'enfance," but the later observers completed the description by the discovery from post-mortem examination that it did not depend upon, nor was it associated with, changes in the spinal cord, but that it was a muscular affection without detectable nervous lesions. They regarded their cases as constituting a distinct and separate variety of myopathy, relying upon the commencement in the face and the absence of hypertrophy, and they refused to recognise the essential identity of their cases with those of Erb, in spite of the fact that in one of their quoted cases the face was not affected, and considerable enlargement of the calves, if it was not present at the time, had been a few years before. The latest and most important contribution to the elucidation of this disease is the work of Erb already alluded to.f In this he subjects to close examination numerous clinical records of cases of the different varieties already referred to, and makes it clear by the observation of cases of different types among members of the same family, by the description of cases which form distinct connecting links between the different varieties, and by the observation of the histo- logical conditions in the affected muscles, that all four varieties — pseudo-hypertrophic paralysis, the juvenile form of Erb, the Lan- douzY-Dejerine type, — identical with the atrophie musculaire pro- gressive de I'enfance of Duchenne — are but branches of a parent stem, and essentially the same disease. He proposes a division into two main groups, viz. (1) children, (2) adults ; and in the former he would distinguish two varieties, the hypertrophic and the atrophic. In the hypertrophic he would further distinguish those with pseudo- hypertrophy and those with true hypertrophy, and in the atrophic variety those with, and those without involvement of the face. Such a division is of course an arbitrary one, for even between the two chief varieties no hard and fast line can be drawn ; and the same is true in a greater degree of the minor divisions. It has, therefore, seemed best to describe the disease on the same lines as have been followed in previous editions of this book, with a due recognition of the fact that any particular case met with may partake of the characters of simple atrophy and also of pseudo-hypertrophic atrophy, and indeed may at one time be regarded as belonging to one group, and at another to the other. All the diseases of this class seem to depend on a defective tendency in * ' Rev. de Medecine,' 1855. f • Dystrophia musnularis progressiva,' Leipzig, 1891. 566 SPINAL COED. tlie development of tlie germinal tissue wMcli forms muscles ; tliej are essentially congenital diseases. Although they are, in most cases, merely potential maladies at the time of birth, and sometimes for years afterwards — even occasionally during a considerable part of life, — the morbid tendency does sometimes attain actual development in the earlier years. But we know nothing, or almost nothing, at present, of any other cause than this developmental tendency; we know nothing of these diseases as acquired maladies, the result of influences acting on a healthy and normal organism. Another fact of their general pathology is analogous to that which we have already considered in connection with developmental diseases of the central nervous system. It depends on the double constitution of muscular as of nervous organs, on the presence of interstitial con- nective tissue between the contractile elements, and on the relation of both to trophic tendencies. An overgrowth of the interstitial tissue may concur with wasting of the fibres, and this overgrowth may be abnormal in its features. Hence Erb has chosen the term, abeady referred to, " muscular dystrophy," as a more precise designation for the class — a term which is likely to obtain general acceptance. The important fact to recognise is that there may be either a simple defect in the growth of the fibres, ultimately leading to their disappearance, or there may be, with this, an overgrowth of the connective tissue, either a simple hyperplasia, or a perverted growthin which f at-ceUs form. These cells increase its bulk, but are ultimately removed. The muscular fibres also sometimes present hypertrophic enlargement, but simple wasting is the most common change. The symptoms by which these changes are manifested vary accord- ing to the nature and seat of the alteration. In all cases muscular power fails as the contractile fibres waste. The chief difference in aspect, however, depends on the seat of the affection and the effect of the interstitial changes, and especially on the frequent enlargement of muscles from the formation of fat in the fibrous tissue. This produces the semblance of hypertrophy that has led to the name "pseudo- hypertrophic -paralysis " being applied to the cases in which it is present. The amount of enlargement varies much ] the fibrous tissue alone may cause none, but it is sometimes great and wide-spread in the cases in which fat is formed. In all, however, a primary shrinking of the muscles, often preceded by a true enlargement of the fibres, is due to the wasting of their proper substance, the result mainly of a defective tendency of vital endurance or growth, and only in a slight degree to the influence of the interstitial tissue when this is increased in quantity. Thus certain varieties are constituted by the external manifestation of the muscular changes. Even in the class in which pseudo-hyper- trophy occurs there may be no change, or only diminution in the size of the muscles, but with increased firmness, as the accompaniment of the lessened power. When there is enlargement, this may or may PSEUDO-HYPERTROl'HIC MUSCULAR PARALYSIS. 567 not correspond in time to the loss of power, since the mnscnlar fibres may waste cither during interstitial growth, or after this tissue has undergone the atrophy which ultimately supervenes. Thus we may have two classes of cases belonging to this type, one with enlargement of muscles, few or many, the other with only wasting of muscles, the two corresponding in position and in the general course and relations of the affection. In another form there is never an interstitial growth of fat, and probably no considerable increase of fibrous tissue ; simple atrophy of the fibres is its pathological characteristic, while primary shrinking of the muscles is its external manifestation. The shoulder muscles are prone to suffer most, and in some cases there is a peculiar affection of the face. These cases are also more variable in the time of life at which the symptoms begin. But these varieties, as we have already state i, are connected by cases which to some extent combine the various features. Such combined forms forbid the separation of the types, which, nevertheless, frequently maintain so distinct a coui'se in many members of a family, even through several generations, that we are compelled to recognise their distinctness, although we cannot divide them altogether. The essential element in the disease has been spoken of as a " quali- tative" defect, which entails an imperfect development, manifested sooner or later by the defective vitality of the proper elements of the tissue. Bat there is reason to believe that the defect is not always merely qiia,litative. In some cases the defect in certain muscles is so absolute at so early a period as to make it almost certain that these muscles or parts of muscles are congenitally absent, and that the germinal effect is thus quantitative as well as qualitative. The muscles in which this apparent failure is observed vary in the several forms, and will be mentioned in the account of these. The peculiar form of atrophy, which differs from the others in the early affection of the muscles supplied by the peroneal nerve, is separately described, and its features are not included in these remarks. PSETJDO-HTPERTKOPHIC MtJSCTJIiAR PaRALTSIS (LiPOMATOUS MusctTLAE Atrophy, &c.). The affection thus designated usually manifests itself during the later developmental period of childhood, and clearly depends on a morbid developmental tendency, which is often present in several members of the same family. It is characterised by a progressive change in the size and diminution in the power of many muscles. The apparent cause of the change has been already mentioned. Isolated cases, which can now be recognised as examples of this disease, were recorded in England in 1830 (Sir Charles Bell) and in 568 SPINAL COED. 1847 .(Partridge), and in Italy in 1838. A series of cases was described by Meryon in 1852, and Oppenheim in 1855, but enlarge- ment of the muscles was not conspicuous in these.* Several remarkable examples had already come under the notice of Duchenne, who was busy exploring the field of muscular paralysis with the aid of " localised electi-isation." He recognised its novel features, and pub- lished an account of it in 1861, under the name by which it has since been generally known. Etiologt. — Our knowledge of the causes of the disease is limited to a few general facts. Males furnish the majority of the cases ; they suffer at least four, and perhaps seven times as frequently as females. In the latter, moreover, the malady is slighter in degree, later in development, and less frequently causes death. The disease occurs rather less commonly in isolated cases than in family groups. The number in a family has varied from two to eight. As many as eight brothers suffered and died in the family described by Meryon, while all the daughters escaped. In a family known to the writer, four sons have suffered and none of the daughters ; in another instance two daughters are affected and no sons. Thus there may be a tendency in a family to the affection of one sex, and not the other ; but, on the other hand, children of both sexes may suffer in the same family. In many instances in which several members of o»e generation are affected, no antecedent cases can be traced in the family ; the malady, while congenital, is not hereditary. In other families antecedent cases can be traced, and these are invariably on the mother's side. The disease is thus transmitted by women who are not them- selves its subjects. In a case in which four brothers suffered, the mother's brother and sister were likewise affected. Again, a brother and sister were diseased, one daughter of a second sister, and three daughters of a third sister. In another instance a boy suffered, and his sister, unaffected, had two sons diseased and a daughter free, of whose children two sons were the subjects of the malady. Thus the congenital tendency is exclusively due to the maternal element in the embryo. This is also shown by a fact many times observed, that the children of the same woman, by different husbands, STiffer in the same way. Indirect hereditary tendencies, such as are indicated by the occur- rence of diseases of the nervous system, can be traced so rarely that it is doubtful if they have any influence. Neither the age of ♦ Nevertheless Merlon's cases ('Med.-Chir. Trans.,* 1852) certainly belonged to this variety. Conclusive proof of the fact is afforded by cases in collaterals which have come under the writer's observation in near and distant branches of the same family. Other evidence of the fact is described in a 'Clinical Lecture on Pseudo- hypertrophic Paralysis * (London, Churchill, 1879). The chief literature is referred to in that lecture; the numerous papers that have appeared since have added chiefly to our knowledge of the characters of the allied forms of idiopathic atrophy, &e., and the relations of these to the pseudo-hypertrophic variety, and are referred to on a later page. PSEUDO-HTFERTROPHIO MUSCULAR PARALYSIS. 569 parents, nor their intemperance, appears influential, and their con- sangtdnitj becomes effective only when raised in energy by repetition. Thus, in a family known to me, the intermarriages during five genera- tions were very numerous, and of eight children in the present family five are albinos, and two of these are the subjects of pseudo-hyper- trophic paralysis. In another family of eight, whose parents were double first cousins, six children suffered from muscular dystrophy^ different forms being represented in different members of the family. The disease always manifests itself during the period of development, sometimes in the early stage of growth, at the close of infancy, often only during mid-childhood, rarely not until growth is nearly ended. In a third of the cases the first symptoms are noted when the child first attempts to walk, which is usually a little later than in healthy children ; very rarely indeed the child has never walked. In about another third the child seems well until it is four, five, or six years old, and then impairment of power attracts attention. In three quarters of the cases the disease manifests itself before the tenth year. Rarely the patient is conscious of no symptoms until after puberty, at the age of eighteen or twenty ; but in such apparently late onset there has been enlargement of muscles long before power became impaired, and the disease began much earlier than it seemed to do. One patient, for instance, in whom weakness was only noticed when she was twenty, had been often " chaffed," when a yoTing girl at school, on account of her " tea-kettle calves." Neither social state nor general constitutional condition seems to influence the occurrence of the disease, but its manifestation has sometimes been apparently accelerated by influences that disturb the general health ; it has been first noticed, for instance, during convalescence from some general illness. Symptoms. — Impairment of power usually attracts attention before any change is observed in the size of the muscles, or if these are noticed to be large, it is with feelings of parental pride rather than with suspicion, in spite of the fact that the children often walk clumsily, fall with ease, and rise with difficulty. The act of going upstairs is especially difficult to them ; the child has to take hold of the banisters and pull himself up. The muscles may at first present nothing unusual, especially in slight cases, or if the child is fat, as is frequently the case. But at the age of five or six years an unnatural enlargement of certain muscles is usually conspicuous, especially when there is a contrast between these and other muscles which are small. If enlargement is almost universal, it is ubually great and conspicuous. The enlarged muscles usually for a time become still larger in comparison with the others, but afterwards they cease to increase and ultimately become smaller, first relatively and then absolutely. This change occiurs earlier in some muscles than in others, and it may result in a condition of distinct atrophy. 570 SPINAL COED. Among muscles that are most frequently large, those of the calf take the first place. They sometimes attain a remarkable size. I have measured a calf 14| inches in circumference in a boy of twelve. The muscles in front of the lower leg are less frequently enlarged, but sometimes project beyond the edge of the tibia. The extensors of the Fia. 155. Fio. 1 Sfi. Fig. 157. Figs. 155 and 156. — Two brothers^ aged four and seven, suffering from pseudo-hypertrophic paralysis. Fia. 157. — Partial enlargement of rectus, the vasti being small. knee are often big ; occasionally the rectus or vastus internus is alone increased in size (the rectus in Fig. 157), and the other parts may be normal or small ; less frequently all parts are small. The flexors of the knee commonly escape. The glutei are frequently conspicuously large ; the flexors of the hip are, of course, inaccessible to observation, but they are usually feeble, and no doubt diseased; there is generally enlargement of the lumbar muscles, and disease of a peculiar and important character in those of the shoulder. Of all the muscles of the body, next to those of the calf, no one is enlarged more frequently or in greater relative degree than the infra- spinatus. It often stands out so conspicuously that its edge is apt to be mistaken for that of the scapula (Figs. 158 and 159). The supraspinatus is sometimes also prominent, but its condition is usually concealed by the trapezius, which is little involved. The deltoid is also frequently large; the serratus rarely. The pectoralis is never enlarged, but, on the other hand, its lower half is wasted or absent PSEUDO-HYPERTROPHIC MUSCULAR PARALYSIS. 571 in a large proportion of the cases, and with this the latissimus dorsi, which has the same action in depressing the raised arm (see p. 37). The teres major may share the wasting of the latissimus. The other muscles of the arm suffer in diminishing degree and fre- quency from above downwards. The triceps and biceps are sometimes enlarged, the former more frequently than the latter, but occasionally only in one part. Both these muscles are sometimes wasted. The forearm muscles suffer in only a small minority of the cases, and the intrinsic muscles of the hand usually escape altogether. This usual escape of the intrinsic muscles of the hand affords a very marked contrast to spinal muscular atrophy, in which they suffer early; Fi(.. 15^. Pheiulo-liyinrtrophic paralysis. Ab>eiice of latissimus dorsi, enlargement of infiaspii:atus. (From a photograph.) Fig. 159. — Wasting of latissimns dorsi and serratus ; enlarge- ment of infraspinatus, supra- spinatus, and fleUoid ; atrophy of biceps and triceps. (By Dr. H. R. Spencer, irom a photo- graph.) hut no rule is free from exception, and although the escape of the hands in the idiopathic affections is almost constant, it is not quite invariable ; slight (or commencing) impHcation of the intrinsic muscles has been met with in very rare instances that were otherwise typical,* * E.g. Sachs, 'New York Neurol. Soc.,* Oct. 2nd, 1888; Baumler, ' Sudwest. Neurol. Verjamml.,' Freiburg, 1888. I have once met with wasting of the extensors of both phalanges of one thumb, and enlargement of the abd. indicis has been observed (Taylor, Clin, Soc, April 24th, 1891), and fatty growth in the thenar muscles (Berger, 'Arch. f. Psych.,' Bd. xiv). 572 SPINAL CORD. and quite distinct from tlie "peroneal type" to be presently men- tioned. The muscles of tlie neck are very seldom affected, but I bave noted, in a few cases, wasting of tbe clavicular part of tbe sterno-mastoid. Those of the face do not suffer except in extremely rare cases intermediate between this and the third type (see also Westphal, * Charite Annalen,' 1887, xii, p. 477), but in the .patient shown in Fig. 162 there was considerable enlargement of the masseters. The tongue has been increased in size in a few instances. The other muscles supplied by the cranial nerves always escape. The diseased muscles are weak, but the impairment of power is to some extent irrespective of the change in size. The muscles that are abnormally small are generally weaker than those that are abnormally large ; and in the latter the weak- ness increases with the wasting. In the legs the greatest weakness is in muscles that are inaccessible to ex- amination — the flexors of the hips ; next in order of weakness come the FlO. 160.— Modeof obtaining extension of hips in pseudo-hypertrophic paralysis. F, ful- crum of the lever formed by the femur. P, mean position at which the power is applied by contraction of the quadriceps femoris. W, position of weight in the ordinary mode of rising, w, the place to which part of the weight is transferred by putting hands on knees. Pia. 161.— Mode of rising from the ground in pseudo-hypertrophic paralysis. extensors of the knee and the extensors of the hip. The muscles below the knee usually retain considerable power for a long time, and the extensors of the ankle fail before the flexors. In the upper limbs the depressors of the arm are usually alone weakened during the early period of the disease, but subsequently the shoulder muscles suffer. PSEdDO-HYPKRTROPHIC MUSCULAR PARALYSIS. 573 then the triceps and the biceps, while the muscles that move the hand commonly retain good power to the last. The distribution of weakness in the legs causes certain peculiai defects of movement which are very characteristic, and some are even all but pathognomonic of the disease. The difficulty in going upstairs is especially due to the weakness of the extensors of the knee and hip. The defect of the extensors of the hip causes the gait to have a peculiar oscillating character, in which the body is so inclined as to bring the centre of gravity over each foot, on which the patient suc- cessively throws his weight, because the weak gluteus medius cannot counteract the inclination towards the leg that is off the ground unless the balance is exact. The greatest defect, however, is in the power of rising from the floor, and the most characteristic peculiarity is the m.ode in which this is achieved, if it be still possible, and no objects are near by which the patient can aid himself. He commonly has not sufficient power to extend the knees when the weight of the trunk is on the upper extremity of the femur, which is then a lever in which the power, applied between the fulcrum and the weight, acts at least advantage. He therefore places his hands on his knees, as in Fig. 160 ; and his arms thus bring much of the weight of the upper part of the trunk on the femur close to the fulcrum, between this and the power, which can then act at greater advantage. Moreover the mere weight of the head which is in front of the arms tends to aid the extension. This, indeed, may effect the extension of the knee without the aid of the extensor muscles, as any one may ascertain by observing the mobility of the patella in this attitude. When the knees are extended the power of the extensors of the hip may be sufficient to raise the body into the upright position, or the patient may aid them by an upward push with the hand as he takes it off. If, however, these extensors are weak, the hands are often moved higher and higher up the thighs, grasping alternately, and thus pushing up the trunk. To get thus the requisite support, the knees must not be quite extended ; and if their extensors have no power the device cannot be employed, and the patient is altogether unable to rise. In many cases, especially when extension of the hip is easy, the patient achieves the extension of the knees in another way; he puts the hands on the ground, stretches out the legs behind him far apart, and then, the chief weight of the trunk resting on the hands, by keeping the toes on the ground and pushing the body backwards, he manages to get the knees extended, until the trunk is supported by the hands and feet, all placed as widely apart as possible (Fig. 161, 2). Next the hands are moved alternately along the ground backwards, so as to bring a larger portion of the weight of the trunk over the legs. Then one hand is placed upon the knee (Fig. 161, 3), and a push with this, and with the other hand on the ground, is sufficient to enable the extensors of the hip to bring the trunk into the upright position. The shortening and contraction of certain muscles lead to another 574 SPINAL COED. group of symptoms — distortions due to permanent alteration in the position of joints. Some of these are produced, as are distortions in other forms of muscular weakness, by shortening of the less affected opponents of the weaker muscles. Thus the knee-joints become fixed by the contraction of the flexors, and the elbow by the contraction of the biceps when the triceps has lost all power. These contractions only occur late, and are usually facilitated by the habitual flexion of the knee- and elbow-joints. But the deformity at the ankle-joint, which results from contraction of the calf muscles, commences earlier, before their opponents are weak, and is the residt of shortening of the muscles. As a consequence of it, the patient cannot get the heels well u pon the ground, and the foot cannot be flext ^. passively beyond a right angle. The gradual increase of the contraction results in considerable " talipes equinus ; " and as power lessens, the patient is able to walk less, and the consequent loss of the extension involved in the act permits a rapid increase in the contrac- tion. Tiie feet, as Fig. 162 shows, soon assume a pos- ture of extreme extension, the dorsum being in a line with the front of the leg, or forming with it a convex curve. A subluxation of the ankle-joint takes place, and the articular Burface of the astragalus, its anterior extremity, and that of the OS calcis, form three prominences under the skin. When this reversal of the ankle occurs, the tibialis anti- cus can no longer act as a flexor. Another deformity, which is due chiefly to muscular weak- ness, is curvature of the spine. An antero-posterior curve, with the concavity backwards, is an early symptom of the disease, and it may become extreme, the upper part of the trunk being carried so far back that a vertical line from the scapula falls an inch or more behind the sacrum. It is due not to the weakness of the trunk muscles, but to that of the extensors of the hip, in consequence of which the pelvis is inclined forwards, carrying with it the lower lumbar vertebrae ; hence the upper part of the trunk has to be held far back to keep the centre of gravity of the body over the feet. The proof of this mechanism is that when the patient sits, and the pelvis is supported on the ischial tuberosities, Flo. 162. — Late stage of pseudo-hjperlro- phic paralysis; a boy fourteen years old, with muscular contraction and wasting, and lateral curvature of the spine. PSEUDO-HYPEfiTROPHIO MUSCULAR PAKALTSIS. 575 the lordosis disappears. It is, indeed, replaced by an opposite curve, in which the back becomes convex, clearly due to the weakness of its extensor muscles. This curve may become very great, as in the case shown in Fig. 163. The weakness of the spinal muscles also permits the occurrence of lateral curvature (Fig. 102), influenced, in its direc- tion, by the habitual posture and the preponderance of weakness on one side or the other. Pig. 163.— Lad aged fifteen ; late stage ; wasting of thighs; inahility to sit upright in consequente of the weakness of the spinal musclea. The electric irritability of the muscles is only altered when distinct weakness or wasting has set in, when it is lowered alike to f aradism and voltaism. There is never any trace of degenerative reaction. The knee-jerk may be at first normal, but as the extensors of the knee become feeble, it is always lessened and gradually disappears. It is never excessive, and in all advanced cases it is lost. Sensation is unaffected, and so also are the sphincters in the vast majority of cases Very rarely there has been, towards the end, a slight difficulty in the retension or expulsion of urine, to be regarded, perhaps, rather as a complication than as an effect of the disease. All other functions of the nervous system are commonly normal, including those of the sym- pathetic. The mental development of the subjects of this disease is generally beyond that of other children of the same age, doubtless on account of the indirect influence of a malady which withdraws them from active amusements ; mental defect is a pure complication. The rate of progress of the disease and its duration vary much. After some years, often between ten and fourteen, the power of standing becomes lost in consequence of the increasing weakness and the con- traction of the calf muscles. When the patient ceases to walk the muscular disease makes more rapid progress, deformities become greater, and the patient may become almost helpless, except in the hands, and jet live on for several years. Death is sometimes due to 676 SPINAL CORD. some intercurrent malady, as an acute specific disease; but generally tlie lessened respiratory power causes some chest affection to develop, or one tliat should be trifling, to become grave. Life is thus ended by acute pneumonia or bronchitis, or by chronic lung disease — a form of pneumonic phthisis or broncho-pneumonia, which develops gradually, with little febrile disturbance. There is never sufficient paralysis of the respiratory muscles to cause death directly. The duration of the stage of helplessness depends very much on the care which the patient can obtain. In the cases in which muscular power remains good until after puberty, the progress of the disease is generally slow. The patient may reach the age of thirty before power is much impaired. It is possi- ble that, in some cases, the disease never attains a considerable degree. More frequently, however, after slight symptoms have lasted for some years, a rapid increase occurs, and very few patients reach the age of forty. The course of the disease is slower in girls than in boys, and females furnish a relatively large proportion of the late cases. Varieties. — The chief varieties of the disease depend on the age at which it commences, and on the condition of the muscles, whether they are large or small. In rare cases a single muscle may be large, and tbe rest small, as in Fig. 164, in which only the vasti were increased in size. Or everywhere and f roxa the first the muscles are smaller than nor- mal, and they progressively waste. Such cases are not uncommon ; in the first group of cases described (by Meryon), enlargement of muscles was inconspicuous. Many cases in which all muscles are small belong properly to the form considered in the next section. But it must be remembered that there are intermediate cases which form links between the two chief types. The cases described by Meryon must be regarded as examples of the pseud o-hypertrophic form (see p. 568), but they present many points of resem- blance to the " simple atrophy " described further on. Complications. — Congenital mental weakness, due apparently to defective development of the brain, sometimes complicates pseudo-hypertrophic paralysis. In rare cases there have been indica- tions of some other morbid condition of the central nervous system^ such as epilepsy. It is uncertain in what hght the slight occasional affection of the bladder is to be regarded, whether as an invasion of the vesical muscles or as a central complication. Yigoroux has recorded a case in which the symptoms of pseudo-hypertrophic paralysis were combined with the peculiar rigidity of Thomsen's disease. Of course the subjects of the disease are liable, like other children, to various Fig. 164.— Enlarge- ment of the vasti and not of the rectus. In this case all other muscles were below normal size. PSEUDO-HYPEKTROPHIC MUSCULAR PARALYSIS. 577 affections of the nervous system ; I have seen both chorea and polio- myelitis as merely accidental complications. Pathological Anatomy. — It is rare at the time of death for any muscles to be actually larger than natural. Sometimes, however, they are enlarged, and the fibres themselves have been found hypertrophied, just as they have been in excised parts. There has also been found a great increase in the nuclei, atrophy of the fibres, vacuolation, and division of fibres. Most of those that are affected are below the normal size. They are pale and yellowish in colour, and often, to the naked eye, resemble perfectly masses of adipose tissue. The resemblance is not merely one of aspect. As seen under the micro- scope, it may be difficult for the observer to realise that he is not looking at a fatty tumour. Nothing may be at first visible but fat- cells, precisely like those of adipose tissue. Among the cells, however, are tracts of nucleated fibrous tissue, and a closer examination of these shows that the tracts contain also muscular fibres (Fig. 165), most of Fl9. 166. — GastrocneTnins muscle; muscular fibres, irregularly nar- rowed and in part degenerated, lie among tracts of nucleated fibrous tissue, separated by adipose tissue. them much narrower than normal. They are also irregular in width ; a broad fibre, for instance (as in the figure), suddenly becoming narrow. The fibres for the most part preserve their transverse striation, but where they are narrowest this may have in part disappeared, either by granular degeneration, or, more commonly, by a simple fading of the strisB. In the narrowed fibres the strise are sometimes farther apart than normal. In other parts broad fibres may be seen, normal or VOL. I. 37 578 SPINAL COED. nearly normal in aspect (Fig. 166), coursing among tlie fat-cells, and accompanied by a smaller amount of fibrous tissue. Fibres occasion- ally present fatty degeneration, a longitudinal striation or fissuring, vitreous ("waxy") degeneration, or vacuolation, but tliese are rare. Some empty sarcolemma sbeatlis may be seen where tlie narrowing of the fibres is greatest. In muscles that still preserve some red tint the amount of fat is less, and there is often a relatively larger amount of interstitial fibrous tissue. Yery rarely, in some part of a muscle there has been only wasting of the fibres, without the interstitial change, present elsewhere (Singer, in the triceps). Fia. 166. — Gastroonemina muscle; two nearly normal muscular fibres, accompanied by fibrous tissue, surrouuded by fat-cells. In some of these the interstitial tissue may be almost entirely fibrous, a few fat-cells only being visible here and there. In such muscles it is common to find the fibres more damaged than in those in which the growth is partly fatty. It is chiefly in the latter that many normal fibres are seen. Muscular fibres larger than normal are sometimes found after death. Such fibres have been seen in frag- ments removed during life by excision, or by a " harpoon- trocar." It has been stated that the increased size was perhaps due to a vital contraction under the mechanical stimulus involved in the extraction. Sometimes, however, the enlargement has been unquestionable (see note, "Muscular Hypertrophy"). The motor nerves, when examined, have been found normal. The ■condition of the sensory muscle-nerves (which terminate in the interstitial tissue in which the primary morbid process occurs) has not been ascertained in any instance. The spinal cord has been found perfectly normal in most cases in which it has been examined. In a ^ew there have been slight and irregular degenerative changes, as in one examined by Lockhart Clarke and myself ;* but the anterior grey • *Med.-Chir. Trans.,' vol. Ivii, p. 247. In this case the cervical and dorsal regions were normal, with the exception of here and there slight accumulationg, at PSEUDO-HTPEETEOPHIC MUSCULAE PAEALTSIS, 579 matter was unaffected, and the changes were probably merely asso- ciated, and not the canse of the symptoms. Haemorrhages have been occasionally found. Probably they have occurred late in life in the degenerated tissue. The neuroglial cells have been found increased in number, and the fibres of the white substance have been found irregu- larly changed, in a few cases, without any constancy in the seat of the alteration. PATHOLoaT. — The common integrity of the anterior grey matter of the cord, and especially of the motor nerve-cells, seems conclusive evidence that the disease of the muscles is not due to a primary lesion of the spinal cord. The slight irregular changes occasionally found are probably consecutive to the long inaction of the cord and deformity of the spine. Pseudo-hypertrophic paralysis is not, therefore, as was at first thought, merely a form of spinal musctdar atrophy with a special muscular change. The significance of the pathological anatomy is that the malady is a primary disease of the muscles, consisting in an altered condition of the muscular fibres, leading, it may be, to enlargement and subsequently to wasting and associated overgrowth of the connective tissue, in which fat may or may not be deposited. The indication of the conditions under which the disease occurs is that it is congenital, the result of a perverted tendency of growth, inherent in the embryo, and derived from the germ from which the embryo proceeds. In this connection it is instructive to note that there is one form of congenital tumour, the structure of which is almost exactly the same as that of the muscles in pseudo-hypertrophic paralysis. Fig. 167 might be a fragment of a muscle in this disease, but it is a section of a myolipoma, the congenital character of which is emphasised by the fact that it was attached to the conus meduUaris of the spiaal cord of a patient whose muscles were healthy. (The tumour is shown also in Fig. 174.) It must have been due to the misplacement of some of the embryonal elements from which muscular tissue is developed, and it shows that, from such elements, the struc- tural condition found in pseudo-hypertrophic paralysis may arise. The points of chief importance in the general pathology of the disease have been mentioned in the introductory remarks. The difficult ques- tion of the precise mechanism by which the muscular fibres suffer must be regarded as an open one. We may assume a defective vitality in them, but the conspicuous lesion is the growth of connective tissue, and by this the fibres are doubtless damaged, whether fatty tissue is formed or not. Indeed, the fibres seem to suffer more when there is the bottom of the fissures, of products of degeneration, probably derived from the perivascular erosion common at all ages. At the last dorsal segment, however, there was an area of granular disintegration in the intermediate grey substance on each side, in front of the posterior vesicular tract. This pwrt was unduly translucent for half a centimetre in vertical extent, and in the middle of this area the disintegration bad produced an actual cavity, across which the fibres for the cerebellar tract ran unchanged. 580 SPINAL CORD. only fibrous tissue than when there is the fatty deposit, although it is chiefly the fat that causes the enlargement of the muscles. There seems to be a tendency to the formation of fat in the early stage of tbe disease, and to its removal in the later stage, since in the former the ■^2277 Fia. 167. — Section of a myolipoma which was attached to the spinal cord ot a man suffering from lociomotor ataxy, for comparison with Figs. 165 and 166. muscles may often be observed to increase in size, and in the latter they become smaller, partly from some removal of fat and partly from the increasing atrophy of the muscular fibres. It is then that the greatest impairment of power occurs. In the cases in which the muscles are small from the first, the tendency to the deposit of fat seems slight, and the condition is an almost pure muscular sclerosis. The late shortening which occurs seems to be due to the contraction of the interstitial fibrous tissue, and it often coincides with the shrinkage from the removal of some of the fat, and the atrophy of the muscular fibres. . If it be true that the latissimus dorsi and lower half of the pectoralis are sometimes congenitally absent in pseudo-hypertrophic paralysis, the fact is quite consistent with the explanation of the nature of the disease given above. These two muscles stand perhaps lowest, in functional importance, among the muscles of the body, being used chiefly for the rare depression of the arm against a resistance (see p. 37). It is readily intelligible that a defect in the embryonal tissue of the muscular system should be quantitative as well as qualitative. The loss of the knee-jerk is sufficiently explained by the lesion of the muscles. According to the theory that the irritability on which the jerk depends is due to a muscle-reflex action, the loss is readily intelligible, since the afferent influence is due to the stimulation, by tension, of the sensory muscle-nerves, and these end (or begin) in the interstitial tissue, which is the seat of the primary morbid process in pseudo-hyperteophk; musculae paralysis. 581 this disease. But the wasting of the muscular fibres must also be capable of abolishing the knee-jerk when the atrophy reaches a considerable degree, and it is also possible that the motor nerve- endings share this structural damage. On any theory of the nature of the knee-jerk, this will explain its loss. It is only when the muscular changes have attained a considerable degree that the loss occurs. The fact therefore does not, in itself, suggest any lesion of the spinal cord. If the malady is thus one of a morbid developmental tendency, it is not surprising that a tendency to analogous developmental diseases should be sometimes present in the nervous system, and that thus imbecility and epilepsy on the one hand, or albinism on the other, should be occasionally associated with the disease. Diagnosis. — The diagnosis of the disease is usually easy if its characters are known. The peculiarity of gait and the mode of rising from the floor, the age of the patient, and the progressive character of the impairment, are in themselves sufficient to suggest the affection, and examination reveals enlargement and often contraction of the caK muscles, and a change in the size of others, which confirm the diagnosis. The mode of rising is not absolutely pathognomonic, and it has misled even good observers ; it is occasionally acquired in other diseases in which there is a gradual weakening of the extensors of the hip and knee. It is met with equally in the simple idiopathic atrophy, but is so rare from any other cause as to be of very great diagnostic suggestiveness. Of the condition of the muscles, that which is most characteristic is the combination of enlargement of the infraspinatus with a wasting of the latissimus and lower part of the pectoralis. I pointed out some years ago * that this condition, which is seldom absent, is of very high diagnostic importance, and subsequent observations have fully confirmed the opinion, Next in importance is the enlargement of the calf muscles, especially in combination with contracture that cannot be overcome. In general, the enlargement and diminution of neighbouriag muscles is very significant, but it must be remembered that they may be gravely diseased, and yet of normal size,. or from the first smaller than normal. In such cases they are often hard, and the distribution of the affection is the same as that of the double change in typical cases. Such cases illustrate the relation of this form to the simple atrophy described in the next section. The disease with which confusion is most common is the so-caUed "congenital spastic paraplegia" (p. 495). Both diseases affect children ; in both there are weakness of the legs and contraction of the calf muscles, and in both the muscles are frequently large. The chief distinctions have been already mentioned. The most important are the preservation and excess of the knee-jerk in spastic paraplegia, the tendency to spasm of the legs — the facts that the contracture is active and can be overcome, that the patient does not rise from the ground * * Pseudo-hypertrophic Muscular Paralysis,* London, 1879. 582 SPINAL COKD. in the way peculiar to pseudo-typertropMc paralysis, — and the oppo- site tendency of the two diseases. Congenital dislocation of both hips sometimes presents a superficial resemblance. Spinal muscular atrophy is only likely to be confused with the simple atrophy. Between the two forms of idiopathic atrophy the distinction is scarcely one of diagnosis proper ; it is rather a question of the category in which a case should be placed. The most important distinction is the freedom of the caK muscles from enlargement in the atrophic form. The face is not affected in pseudo-hypertrophy as it often is in idiopathic atrophy, except only in some intermediate instances. If more than one member of a family is affected, some of the sufferers will usually present characteristic symptoms of the special form, for it is remarkable with what constancy the two types generally remain distinct (see p. 567). Pkognosis. — In the case of any child with pseudo-hypertrophio paralysis, the prognosis is most grave. It is almost certain that each year will bring increasing disability, and that the patient will not reach adult life. It is only when the disease develops late, and the symptoms do not become considerable until after twenty years of age, that there is a possibility that the disease may not attain its ultimate degree, but even in such cases this hope is seldom realised. In any case, and at any age, it is unhkely that the patient will live more than seven years after the power of standing is lost. But even in this con- dition arrest seems to take place in the progress of the disease. One patient is known to the writer who presents a typical picture of the pseudo-hypertrophic type, who is now over forty, and has never been able to run. He has remained stationary certainly during the last eight years, probably longer. Treatment. — As a congenital developmental malady, pseudo-hyper- trophic paralysis is one of those diseases in which medicine is neces- sarily powerless to cope with the essential elements of the process. As may be therefore expected, no drug has been found to exert an influence on the course of the affection, although such nervine tonics as phosphorus and arsenic have been thought sometimes to retard for a time the progress of the weakness. The stimulation of the muscles by electricity has been employed and advocated, but, howeTOr sedulously employed, no distinct result follows the use of either faradism or voltaism. It must be remembered, moreover, that electricity is a very feeble agent in stimulating the growth of muscular fibres, compared with the physiological stimulus of voluntary effort. Muscular exercise may reasonably be looked to in order to make up, in some degree, what is lacking in this disease, and does seem to have some influence in retarding the failure of power. It may perhaps induce further growth, or greater power in the muscular fibres that have not yet suffered, or actually supplement the defective trophic energy. When muscular exercise is stopped, there is certainly a quicker failure of strength. Hence it is desirable that the patient should carry out SIMPLE IDIOPATHIO MUSCULAR ATROPHY. 588 carefully planned gymnastic exercises, so arranged as to call into action tne muscles that most need help. These, thoroughly per- severed in, have seemed, more than any other means, to retard the disease. Although they have not in any case arrested it, the trouble that is necessary to arrange the method is certainly well spent. Eubbing and massage improve the circulation, and help, especially when combined with passive movements, to lessen the tendency to muscular contraction and consequent deformities. The influence of muscular exercise renders it very important to maintain locomotion as long as possible. The ability to stand and walk is generally lost, through the contraction of the calf muscles, some time before the muscular weakness would take the patient off his feet. In such cases tenotomy may restore the power of walking for some years, and when the contracture returns, its removal has, a second time, enabled walking to be resumed. The operation is thus distinctly beneficial, and should be performed as soon as the actual need for it arises, and division of the tendon is far better than any imperfect substitute. During the later stages of the disease great care is required to preserve the patient from catarrh, which helps to excite the pulmonary mischief that so often ends life. Similar care is also needed during any intercurrent malady which the patient may contract. Simple Idiopathic Muscular Atrophy.* The cases in which there is no muscular enlargement, in which wasting is manifest from the first in the size of the muscles, are much more rare than the pseudo-hypertrophic disease. They belong to several types, more or less distinct, of which the most common is that to which Erb has given the name of " juvenile," and of which most instances are probably the pseudo-hypertrophic disease without mus- cular enlargement; others are more special, since the lower limb muscles have suffered but little. A more striking variety is that which is characterised by the affection of the muscles of the face in addition to those of the shoulder girdles — the " facio-scapulo-humeral type " of * The most important writings on the subject (besides those specially quoted) are those of Duchenne in 'Electrisation localise' (p. 60of Poore's translation, published by the New Sydenham Society); Barsickow, 'Inaug. Dissert.,' Halle, 1872 j Leyden, * Klin. d. Ruckenm. Krank.,' Bd. ii, p. 525 ; Mobius, " Hered. Nervenk.," Volkmann'a • Klin. Vortrage,' No. 171 ; Landonzy and Dejerine, ' Revue de Med.,' 1885, pp. 81 and 251 ; Marie and Guinon (a series of cases observed at the Salpetriere), lb., 1885 ; Sachs, 'New York Med. Journ.,' Dec. 15tb, 1888; Hitzig, 'Berlin, klin. Wochen- 8chr.,* 1888 ; Singer, * Zeitsch. f. Heilk..' Bd. viii. Especially valuable are the papers by Erb, 'Deut. Archiv f. klin. Med.,' Bd. xxxiv, 1884, and 'Neurol. Centralbl.,' July Ist, 1886, with numerous later writings. Bibliographical references, &e., will be found also in Tooth's * Thesis on the Peroneal Type,' and in my Lecture on Pgeudo-hypertrophic Paralysis (1879), and in Sachs' article (loc. cit.). 684 SPINAL COl?D. Landotizy and Dejerine. In a tliird variety the affection begins in the legs, and is peculiarly slow in course. Some other types may ultimately be differentiated, but it is important to re(;ognise the fact that even those that we can now distinguish, as the most pronounced in their features, do not keep entirely distinct. They are connected, . . w " " : " / Fia. 168. — Simple idiopathic muscular atiophy. From photogiaphs kindly lent by Dr. J. H. Crocker. Particulars of these cases and many similar are given in an excellent tiiesis on this disease by Dr. Crocker. by intermediate forms, not only with each other, but even with the pseudo-hypertrophic disease, as already mentioned.* But these are ■unusual ; as a rule the two latter types remain distinct in the families in which they occur, and this is the justification for their separate description. In those families in which simple muscular atrophy occurs, however numerous the cases, however different the distribu- tion of the disease, and however various the ages at which it begins, cases rarely present the distinctive characters of pseudo-hypertrophic paralysis. There is less constant separation between the simple " juvenile " and the facial forms. Although they often keep distinct, the affec- tion of the face has been absent in a few cases in a family in which it • JB. g. case described and collected by Marie and Guinon (loc. cit.), connecting the pseudo-hypertrophic form with both the juvenile and the facial. SIMPLE IDIOPATUIO MUSODLAR ATROPHY. 585 was the first part to be affected in most sufferers. Thus a man with simple atrophy, beginning at fourteen in the shoulder and thigh muscles, whose face was unaffected, had a daughter who began to suffer at eleven, and in whom the face, scapular, and arm muscles were involved.* The peculiar " peroneal type " is not included in this outline, and the statements here made do not ajDply to it. Causes. — We are able to trace no cause beyond the congenital tendency, already considered, shown by the occurrence of many cases in the same family, and in more than one generation. In one remark- able series recorded by Barsickow, twenty-four cases were distributed through five generations, and the disease was also traced through five generations in a group described by Landouzy and Dejerine It is very rare for the disease to be confined to one generation, far more rare than for pseudo-hypertrophic paralysis to be so confined. But, as in the case of most congenital hereditary diseases, cases that are apparently isolated are occasionally met with. Such isolated cases are rare — more so, probably, than in the pseudo-hypertrophic form; al- though wider observation may show that they are more frequent than we now suspect. In the families of the patients shown in Figs. 169-172 no example of analogous disease could be heard of. Both sexes suffer ; in a few families, females chiefly ; in others, males ; in most, both have been affected. The age at which the disease first manifests itseK is extremely variable. It may begin as early as two t or three,;}: and as late as sixty years. But the onset is seldom during childhood; in the majority of cases the disease shows itself between fifteen and thirty-five ; that is, during the later period of growth and the early period of adult life. Even in the same family, the variations maybe extreme; in that described by Barsickow tbe date of the onset of seventeen cases was known, and was as follows : — in one at 12 ; in four between 15 and 20 ; in seven between 20 and 30 ; in three between 30 and 40 ; in two after 40. A woman aged fifty-two began to suffer at 30, but her son at 3 years of age.§ Sex has no influence on the date of onset, nor, as a rule, can any relation be traced between the date and the place at which the wasting begins. When the wasting begins in the face, the disease more frequently commences in childhood than when the first symptoms are in the limbs, but in some instances the atrophy has commenced in the face late in life, and this in the same family in which other sufferers have been young. Thus in the sexual I'roclivity, and in the date of onset, there is a marked difference between this form and pseudo-hypertrophy, the latter showing a stronger tendency to affect males, and to manifest itself in childhood. The " juvenile " form, as a rule, presents less difference. * Troisier and Guinon, 'Rev. de Med.,' 1889, p. 48. See also Singer, *Zeit. f Heilk.,' viii, p. 229. t Kreske, * Munch, med. Wochenschr.,' 1886. J Landouzy and Dejerine, loc. cit. § Ibid. 586 SPINAL CORD. As a rule, no direct exciting' cause can be traced. In a few instances tlie onset has succeeded some other morbid process, such, as chlorosis, acute disease, or rheumatic affections due to exposure to cold ; and the depression of general health resulting from these may have determined the time of onset, but is not likely to have done more. In other in- dividuals of the same families the disease has developed without the aid of any exciting influence. Symptoms. — The onset is always gradual. Weakness and wasting come on together, and are noticed simultaneously, unless the com- mencing atrophy is concealed by subcutaneous fat. The atrophy generally begins in the upper arm and shoulder muscles, having, in the most common " juvenile " form, a similar distribution in these parts to that of pseudo-hypertrophic paralysis. In the facial form, however, this part usually suffers first, as in the lad figured on p. 589. In rare cases the wasting not only begins in the legs, but remains limited or almost limited to them. In the part first affected the dis- ease slowly increases, and thence it usually spreads. The onset may be symmetrical on the two sides, or one side may suffer some time before the other. Of the arm muscles, the weakness and wasting are noticed first in the biceps and triceps, and with these the supinator longus often suffers. But examination generally shows that the lower part of the pectoraHs and latissimus dorsi are greatly wasted, a loss of which the patient may be little aware, on account of the relative unimportance of these muscles. Sometimes the upper part of the pectoralis, and even the pectoralis minor, are also affected. The tendency to atrophy of the lower part of the pectoralis and latissimus is a character which, as already stated, is common to this disease and pseudo-hypertrophic paralysis, but not invariable in either. The deltoids are rarely in- volved ; in many cases they are normal ; sometimes they have been thought to be unduly large ; in a few instances they have been wasted. The serratus magnus is often affected (Fig. 172), but may escape, even in a severe case. The supraspinatus and infraspinatus may also suffer, but are often normal, or even enlarged; the trapezius and rhomboids have been affected in many cases ; sometimes much atro- phied, especially in the " juvenile" form. The forearm muscles generally escape, with the exception of the supinator longus. Occasionally there has been some weakness of the long extensors or flexors of the fingers, with or without slight visible wasting. In the case mentioned on the next page the extensors of the phalanges of the thumb were involved on the left, and the radial extensor of the wrist on the right side. Earely the forearm muscles have been much atrophied. In several instances there has been some atrophy of the small muscles of the hands, the thenar and interosseal muscles, or the interossei only, as in the case of Landouzy and Dejerine ; but in the majority the integrity of these muscles is a marke-d feature of the disease and a contrast to the spinal form. SIMPLE IDIOPATHIC MUSCULAB ATEOPHT. 587 The affection of the face is peculiar. There is commonly a failure of the zygomatic muscles, and, in consequence, a loss of the naso-labial furrow, and a curious alteration in the smile ; instead of the angles of the mouth being drawn outwards and upwards, they are moved upwards by the elevators of the upper lip and angle of the mouth. The orbicularis oris is also affected, and, in consequence, the lips arehabitually separated, the lower lip projects, the patient cannot "pout" or whistle, and the articulation of labials is imperfect. The face has a dull expression, and the aspect ' is very pecuUar ; it has been termed, by Landouzy and Dejerine, the " myopathic face." In one case, observed by them, the face was unequally involved on the two sides. Earely (as in Fig. 171) the frontales have been involved, and the orbicularis palpebrarum has been weak, and the eyes cannot be completely closed. Weakness of the eyeUds was supposed to be the cause of distinct exophthalmos present in one woman.* In the case described by Kreske, inability to close the eyes was noted at three, and at ten the paralysis of the face was absolute. Wasting of the muscles may be indistinct, because the contour of the face is only to a slight degree influenced by the substance of the muscles The projecting lower lip may, indeed, appear to be thicker than normal. In many cases the buccinators have been affected, in some instances they have been normal, and then have drawn out the angles of the mouth in smiling. The tongue has been always un- affected, and so also have the pharynx, larynx, muscles of mastication, and the eyeball muscles. f The muscles of the spine have sometimes been normal, sometimes they have been considerably atrophied.^ The intercostals are often • Landouzy and Dejerine. t In a singular case under my care some years ago, an affection of the facial ■muscles, similar to that of idiopathic muscular atrophy, was associated with paralysis of ocular muscles. The patient was a girl twenty-seven years of nge ; there were no indications of syphilis, nnr could any history of muscular atrophy in the family be ascertained. The ocular palsy commenced gradually at twenty-four, and increased until the movemeitts of both eyes upwards, of the left eye inwards, and tlie right out- wards, were lost, and all other movements were weakmed. Thu eyelids drooped sligh I ly ; the intei ii:il ocular muscles were normal. The affection of the face followed tliat of the eyes; the zygomatic muscles were powerless, so that the smile consisted only in elevation of the upper lip; the orbicularis was weak. The palate, pharynx, and iHiynx were normal. The arms became feeble, and the flexors of the hips almost powerless. There was no visible change in the nutrition or electrical irrita- bility of the muscles; the knee-jerk was normal. If the case was central, as it appt^art'd to be, the peculiar affection of the lips and zygomatics is not confined to idi(ipnthic muscular atrophy. If the disease was muscular, the eyeball muscles do not invariably escape. With this case may be noted one recorded by Oppenheim ('Charite Aniialen,' xiii) as the "juvenile" form, with derangement of the lateral movement of the eyi's, nystagmus, and some laryngeal palsy. The shoulder and thigh muscles .suffered chiefly, but below the knee, the peronei — a noteworthy aberration from the type. J Atrophy began in the back muscles at forty-four in a case recorded by Musio 588 SPINAL CORD. affected in the later stages, but rarely in extreme degree. .The diaphragm also sometimes suffers. The abdominal muscles have bjen involved in only a few instances. In the legs the muscles most commonly affected are the flexors of the hip, the extensors of the knee, and less frequently the glutei. The muscles below the knee have escaped in many cases ; when they have suffered, the atrophy has often been general, ^^'hen the peroneal and anterior tibial muscle- have been specially affected, as in the case shown in Fig. 172, the case has generally b^en of the peculiar "j^eroneal" type to be presently mentioned, although it is possible that some instances of the kind are on the borders of the group now under con- sideration. The electric irritability of the affected muscles is usually lessened in proportion to the wasting, and equally to both currents. Indeed, the diminution seems sometimes out of proportion to the wasting, and great when the atrophy is slight. There is no trace of degenerative reaction, and there is not even the longer persistence of voltaic than of f aradic irritability which occurs in the more chronic cases of spinal atrophy. Fibrillation is almost always absent, but not quite in- variably ; hence its absence cannot be made distinctive, stiU less its presence. Myotatic irritability is lessened or lost ; it is never increased. Some shortening of muscles has been occasionally noted, frequently in the calf muscles, rarely in the biceps. All other functions of the nervous system are unaffected. Sensi- bility is normal. In a few cases transient rheumatoid pains have accompanied a rapid development of the disease in the arms, but in the vast majority of cases the disease is painless. The sphincters are unaffected, and there is no tendency to trophic or vaso-motor dis- turbance. As the muscular atrophy progresses, the form of the affected parts becomes changed just as in spinal atrophy. Deformities may also occur, chiefly from the shortening of less affected muscles, but these rarely reach the considerable degree common in other forms of muscular wasting. Lordosis occurs in the upright posture, and is probably due to the same mechanism as in pseudo-hypertrophic paralysis, ceasing, as in that disease, when the patient sits (compare Figs. 169 and 172). When the muscles of the lower leg are involved talipes may develop. The course and duration of the disease are exceedingly variable. The atrophy may remain limited to the part in which it begins. The face alone ha « been affected in some members of a family, although in other members the limbs subsequently suffered. In cases in which the wasting spreads, years may intervene before the extension takes place. In one case, for instance, the right arm became affected at {' Riv. Clin.,' June, 1887), and twelve years later hud involved also the legs. The pritient's mother, two brothers, sister, and maternal uncle suffered in the same way at the same age. SIMPLE IDIOPATHIC MUSCULAR ATROPHY. 589 nineteen, the left at twenty-five, and tlie legs at thirty. In another the arms began to waste at thirty-five, power of standing was only lost at fifty-five, and the patient lived till seventy-five. Even when the malady I'ra. 1fi9. Fro, 170. Fro. 171 Figs. 169 to 171. — Idiopathic muscular atrophy affecting the face. Fig. I(i9 shows the wasting of the deltoid upper arm muscles and supinator lontrus (while the forearm muscles are not wasted), and the rotation of the scapula from the loss of the trapezius and rhomboids. Fig. 170 shows the habitual appearance of the face, and Fig. 171 the greatest possible movement of tlie facial muscles in closing the eyes and smiling, and also the wasting of the deltoids and pectorals. The general distribution of the atrophy and projec- tion of the scapnlse are seen in Fiir. 172.* • The patient was a lad sixteen years of age. The following is an abstract of the notes of his case. In his family no history of any similar affection can be ascertained. There is conclusive evidence that he had a hard chancre at the age of three, followed by secondary symptoms. The muscular wasting began gradually during childhood; even when very young there was little movement in the face, and that ceased at the age of six or seven. Walking became difficult about three years ago. The face is almost motionless: an effort to smile causes only a just perceptible movement of the left cheek, the amount of which is fairly indicated by the difference between Pigs. 170 and 171. It is accompanied by a distinct movement of the ears. The lips are full and can be brought together, but not shortened. The eyelids cannot be made to meet, even with a strong effort, being then | inch apart. Forehead absolutely motionless. Eyeballs prominent, movements normal. Masseters, tongue, pharynx, and larynx unaffected. In the neck the sterno-mastoids are very small and feeble, the cmo-hyoids large and strong. The following muscles seem quite gone^ 590 SPINAL OORD. Pra. T begins in childhood its progress is sometimes very slow. Thus in one case the affection of the face was first noticed at five, at twelve the arms began to suffer, and a few years later the flexors of the hip became weak, but the patient was still able to walk at the age of forty. The disease may increase until deve- lopment is over and then remain stationary, as in a case in which, at forty-four, there had been no change since the age of twenty. The patient's daughter was more severely affected.* On the other hand, the progress of the disease may be more rapid and uni- form, and the atrophy may reach its widest distribution in eight or ten years. In most cases, even of severe type, the wasting docs not become universal, but remains limited to the muscles mentioned above, but occasionally hardly any muscles of the body may escape. The duration of the disease varies from ten to fifty years. Death has never occurred as the direct result of the malady. In the cases of most severe degree and rapid course the patient has usually died from phthisis, pro- bably related to the deficient breathing power, just as in the sufferers from pseudo-hypertro- phic paralysis. In most cases, however, death has been due to other maladies, and has not been in any degree the consequence of the muscular disease. Pathological Anatomy. — In general, the condition of the mus- cular fibres resembles that met with in pseudo-hypertrophic para- lysis, the increase of interstitial tissue being wanting except in those trapezius (except, perhaps, a little of the middle part of the right), rhomboids, deltoid, peotorales, latissimus dorsi, serrati, biceps, bracliialis, triceps, supinator longus. The lev. ang. scapulse, supra- and infra-spinatus are unaffected; the latter is large, but probably only hypertrophied from over-use. The supinator longus is fei hie on the left, powerless on the right side. The extensors of the phalanges of the thumb are lost on the left side, and the extensor carpi radialis on the right. All the other forearm and hand muscles appear to be unaflfected. The erectors of the spine are small and feeble; intercostals strong, diaphragm powerless, abdomin;il muscles weak. In the legs the glutei and flexors of the knees seem normal, the flexors of I he hips weak, extensors of the knees small and feeble, muscles of the lower leg rather small and feeble, but only the peronei are powerless, right-angled contracture of ankle-joint with tendency to varus. Knee-jerk absent. Circumference (in inches) of upper arms (middle), R. 5-^, L. 5|-; of forearm (maximum), each 8; of tliighs (minimum 2J inches above patella), fl. 10^, L. 9^; calves (maximum), R. lOf, L. 11. Electric irritability much lowered in all aff'ected muscles to each current; in most, no contraction can be obtained. Sensation, the sphincters, and the viscernl functions are unaffected. • Landouzy and Dejerine, loc. cit. SIMPLE IDIOPATHIC MUSCULAR ATROPHY. 591 cases that really belong to this form, but in wliicli the characteristic enlargement is absent, because no fat-cells are deyeloped in the tissue. A multiplication of nuclei is, however, sometimes seen. The chief change is sometimes a simple narrowing of the fibres, "vith an ultimate disappearance of the transverse striation. Degenerative changes are frequently met with, indistinct striation or granular, fatty, or " waxy " transformation being seen here and there, alike in narrowed or enlarged fibres, and in those that retain their normal calibre ; occa- sionally fibres present longitudinal striation, fissuring, or vacuolation ; but in other cases, or in some muscles (especially in the "juvenile" form), a remarkable increase has been found in the size of fibres in excised fragments,* even of muscles that are below the normal size. It seems to show definite pathological enlargement. The statements made regarding the spinal cord in the pseudo- hypertrophic form are strictly applicable also to this variety. It is normal as a rule, to which exceptions are so rare that they can have no relation to the malady, save that of secondary indirect consequences. The nerves also are normal, if the cases are eliminated in which the symptoms indicate the peroneal form. Thus the facts ascertained regarding this type do not suggest any special addition to the general conclusions intimated in the introduc- tory paragraphs. The affection appears to be the result of a primary developmental tendency, involving the muscular tissue only, and cannot be regarded as a secondary result of the interstitial changes, except in a trifling, occasional, and unimportant degree. Still less is it a consequence of changes in the spinal cord. If it is in any measure the result of failure in the nutrition of the terminal structures of the nerve-fibres (by which the nervous and muscular tissues are connected, and which is perhaps to be regarded as intermediate between the two) , the fact has yet to be demonstrated, and its significance ascertained. Diagnosis. — The two most important diagnostic indications are the affection of more than one member of the same family, and the onset of the disease before adult life is reached. The former is practically conclusive ; and the latter should always suggest the probable idiopathic nature of the case. In isolated cases the diagnostic difficulty is much greater, and no indication is actually conclusive, except, perhaps, the affection of the face. Commencement during childhood is also of great weight. It is most unlikely that progressive muscular atrophy, begiuning under ten, is of spinal origin, but I have known such atrophy, certainly spinal, to commence at the age of fourteen.f The peculiar affection of the zygomatic muscles is very characteristic, but we cannot yet say that it is pathognomonic (see note on p. 587), and the affection of the lips must be carefully distinguished from that due to the bulbar palsy so commonly associated with spinal atrophy. Of * See especially Schulze, ' Ueber deu mit Hypertrophie verbundenen Maskel* fichwund.' Wiesbaden, 1886, and Hitzig, loc. cit. t See, however, p. 597. 592 SPINAL CORD. tlie distribution of the -wasting, that of the latissimus and lower half of the pectorahs, and the escape of the hand muscles are the most im- portant characteristics, although they are not by themselves con- clusire, since they are sometimes met with in spinal atrophy. But the most important distinctions between spinal and idiopathic atrophy, whenever they are available, depend upon the symptoms of a lesion of the cord, or of the bulbar nuclei. Especially significant is the excess of the knee-jerk which results from lateral sclerosis, a conclusive indication of spinal disease, rendering the spinal origin of the atrophy all but certain. The distinction from the pseudo-hyper- trophic form has been already considered ; that from the peroneal type will be presently mentioned. Prognosis. — The extreme variations in the course of the disease render the prognosis in any individual case both uncertain and difficult to formulate. Speaking generally, chronicity favours arrest, and the later the symptoms appear the slower will be their progress. The prognosis is distinctly less grave in the simple atrophy than in the "juvenile " atrophic variety of the pseudo-hypertrophic disease, and in a considerable number of cases, perhaps one half, the malady has not appeared to shorten life. Even in cases that begin during youth it is therefore possible that the patient may reach old age. It seems also to be better in the cases that do not involve the facial muscles. Teeatmbnt. — It is not yet clear that idiopathic muscular atrophy can be influenced by treatment in any considerable degree. Most published records of cases are almost silent on the subject, and the disease is so rare that few individuals have an opportunity of forming an opinion. It might be assumed that the essential cause of the disease, a congenital tendency, withdraws it from the range of thera- peutics, but the course of the malady is very different from that of some other diseases which own a similar cause. The extreme variations in the date of onset, the fact that the disease may not be manifested until late in life, and the long period that may intervene between its onset and extension, all suggest that other influences co-operate with the congenital tendency in determining the development of the malady. It is quite possible, therefore, that the first inference from the history of the disease may not be altogether correct, although it must be admitted that we have not as yet any evidence that the disease is susceptible of influence from drugs. Electrical treatment and mass- age have been thought to do good and even to produce arrest (Erb), but the variable tendency of the malady renders the evidence of arrest insufficient. If voluntary exercise is practicable, this is a far more efficient stimulus to muscular growth than any electrical application, and it is probable that such exercise, carefully persevered in, may do something to prevent the occurrence of the malady in those pre- disposed to it, and even to retard its progress in those who are already attacked. In this connection it is noteworthy that very few of the sufferers have been engaged in occupations that involve active PERONEAL TYPE OP AMYOTROPHY. 593 mnscular exertion. Over-exertion should, however, be carefully avoided. Tlie general health should be attended to, and any defect removed as speedily as possible, both in those who suffer and in those who are related to sufferers, since, as we have seen, depressing influences may apparently excite the development of the disease, and it is therefore reasonable to suppose that they may accelerate its course, and lessen any tendency there may be for the morbid process to become stationary. The Pbeoneaii Type of Famtlt Amtoteopht. {Neuritic Muscular Atrophy.') The name " peroneal type " has become current as the most con- venient designation for the variety of muscular atrophy, occurring in early life, to which it was applied by Dr. Howard Tooth in a Thesis published in 1886.* This was the means of calling general attention to the form, of which, however, an account had been published shortly before by Charcot and Marie,t and many cases had been pre- viously described, in most instances without recognition of their special character. J The cases of this form present certain resemblances to the idiopathic atrophies just described — resemblances sufficiently important to have led to the description of these cases in association with the primary myopathies, embracing, as they do, the age of the sufferers, the occurrence of the disease in members of the same family, its gradual onset, and its very slow but progressive course. Yet this position must be regarded as provisional only, and probably erroneous. The distribution of the wasting involves a constant difference from the idiopathic musc\ilar affections, and some of the cases, otherwise inseparable from the rest, present features that indicate neuritis. The condition may have, as an antecedent, an acute specific disease — a circum- stance that has the same significance. The facts ascertained con- cerning this form must, therefore, be carefully excluded from our generalisation regarding idiopathic atrophy. In this disease, males suffer about twice as frequently as females. It generally begins in the second half of childhood, and very seldom after twenty, although cases have been described beginning as late as forty. It is occasionally hereditary, and still more frequently collaterals suffer, several brothers and sisters being affected. The wasting is first apparent in the extensor longus hallucis, or extensor communis digitorum, or in the peronei muscles. According to Tooth it very often begins in the latter, and occasionally m the gastrocnemius, but it is probable that it occurs simultaneously or ev^en earlier in the * * The Peroneal Type of Progressive Muscular Atrophy,' London, Lewis, 1886. t • Revue de Med.,' 1886, p. 97. J By Friedreich, Eichliorst, Oppenheimer, Ormerod, and others. A table of thirty collected cases (some doubtful) is given by Tooth. VOL. I. 38 594 SPINAL COED small muscles of tlie foot, where it readily escapes observation. Such early atrophy ia the feet has, iadeed, been actually found in some cases that came under observation at an early stage.* The calf muscles suffer subsequently, and still later those of the thigh, especially the vastus internus. The unequal affection of the muscles of the leg causes the early development of club-foot, which, especially in children, becomes a characteristic symptom.f The arms are only invaded, in most cases, some years after the legs, so slow is the course of the disease. The intrinsic muscles of the hands (thenar, hypothenar, and interosseal muscles) are first attacked, and subsequently those of the forearm : sometimes the extensors and sometimes the flexors suffer first and most ; while the supinator longus remains normal, and so do the muscles of the shoulder, neck, and back. The affection, however, does not necessarily commence in the lower limbs, and the face may be affected (Hoffmann). The atrophy is often symmetrical, but occa- sionally the muscles on one side waste first a,nd most. The claw-like deformity of the fingers may result from the affection of the intrinsic muscles of the hand. This is so rare in early life from any other cause that its significance is considerable, and almost distinctive when combined with the deformity of the feet just mentioned. The ca,se shown in Fig. 173 was probably an example of this type. J Fia. 173. — Advanced muscular atrophy, probably of the "peroneal type." (Drawn by Dr. Spencer, from a photograph.) The affected muscles (especially in the hand) occasionally present slight fibrillation. Their electric irritability is diminished sooner, and • Hoffmann, 'Arch. f. Psych.,' xx, p. 660 j Joffroy, ' Gaz. Hebd.,' 1886, No. 18. t See Sachs, • Brain,' Winter part, 1889. J lb was given in the first edition as an example of simple atrophy. The patient was a man aged twenty-seven at the time of his death (in University College Hospital). No history of any analogous case in his family could be ascertained. The affection began at the age of fourteen, when his feet began to turn in so that he walked on the outer side of the foot, and soon he noticed graduiil wasting of the legs, which slowly progressed, and about the age of twenty-four the arms also began to suffer. "When first seen, a few months before his death, the muscular atrophy was universal, and the subcutaneous fat had also disappeared. Even the hands were greatly wasted; there was a hollow in the position of the thenar eminence, just as in progressive muscular atrophy, and the interosseal muscles were also greatly wasted. There was slight fibrillation. The intercostals were paralysed. The wasting of the legs was extreme; the maximum circumference of the calf wai PERONEAL TYPE OF AMYOTROPHY. 595 in greater degree, than in tlie ordinary idiopathic atrophy .while a stiU greater difference is presented by the fact that f aradic irritability may early become extinct, and that there may be a distinct reaction of degeneration. In connection with this should be noted the important fact that cutaneous sensibility, though often nonnal, is sometimes impaired or lost, especially over the region in which the atrophy is greatest, or upon the soles of the feet. Pains occur in some cases, and so also do spontaneous spasmodic contractions, especially in the muscles of the thigh. The muscle-reflex action is lessened or lost in the affected regions, but there may be extensive atrophy below the knees, without loss of the knee-jerk, if the thigh muscles are pre- served. Cutaneous reflex action presents considerable variations, aaid is preserved more often than would be expected. Yaso-motor dis- turbance sometimes occurs (Sachs). The nature of these cases has still to be demonstrated. Their very slow course, the time of life at which they begin, and the affection of several members of the same family, are features analogous to the idiopathic atrophy ; but a marked contrast to this is presented by the tendency of the malady to succeed an acute specific disease, measles, and this also may appear as a family tendency. This feature re- sembles the causation of multiple neuritis, and the electrical reaction of degeneration is conclusive proof of preponderant changes in the motor nerves, while anaesthesia demonstrates that, in some cases, the sensory fibres are also affected. In such cases a peripheral neuritis, motor or total, of extremely chronic course and peculiar origin, must be recognised as the only possible lesion, and it was actually found, in one case by Friedreich, and in another by Gombault. Dubreiulh* also, in a case which he examined, found that there were inflammatory changes in the nerves, the spinal cord being normal. If this is the cause of the symptoms in some instances, the question arises whether it is not the lesion in all the cases of this peroneal type. Such a lesion is conceivable; the degenerative form of neuritis presents every degree of chronicity, and may be limited to the motor fibres and to certain muscles. This pathology was advocated as the probable one by Tooth, who pointed out that it would also enable us to understand the occurrence of fibrillation, which is extremely rare in the idiopathic atrophies. It is, indeed, asserted by Hoffmann that not only are the peripheral nerve-fibres the seat of a primary degene- ration, but that this change ascends the nerves to the anterior and posterior roots, and involves, in a secondary manner, the elements of only seven inches; the feet were everted, the sole hollowed, and the toes flexed. The patient died from diarrhoea. The muscles were foaud to be small and pale. The chief microscopical change was intense granular and fatty degeneration of the fibres. A very few normal fibres were seen in some muscles. There was no increase ot interstitial tissue. Microscopical examination revealed no morbid changes in the spinal cord. The nerves, unfortunately, were not examined. * • Rev. de Med.,' 1890; *Neur. Cent.,* 1891. 696 SPINAL CORD. the spiual cord, especially the fibres of the posterior median columna (which continue the path from the muscles) and the motor cells of the anterior cornua. But we do not know how far the premature failure of nutrition is a secondary process, transmitted from below, . or how far it is the result of a defect in vital energy, shared by the central as well as the peripheral nerve-elements. I'he intimate relation between the motor nerves and the nniscular fibres should also be kept in view in this connection. There may be a morbid tendency in the nerves similar to that of the muscles, including a liability to early slow degeneration, analogous to that which the muscles present, and equally prone to occur in several members of a family. iut it is desirable that the neuritic nature of the affection shoula oe placed on a broader basis of ascertained fact before it is -liliowed expression in the name given to the disease. It should also be remembered as possible that the atrophy may be idiopathic in some cases, while in others it may be secondary to such a neuritis as above mentioned. There is nothing difficult, or even anomalous, in the conception of a congenital tendency to premature failure of nutrition in the peripheral nerve-fibres, like that which, in the posterior column and other fibres, seems to underlie " hereditary ataxy," or which, on the other hand, in the muscles is the apparent cause of idiopathic atrophy. Further, if the lesion is really neuritic, we can understand that an acute specific disease like measles should occa- sionally be its excitant, although its occurrence in famihes shows that a congenital tendency must be called into activity by the virus, and the cases must be distinguished from those in which a pure neuritis is in- duced by the influence of the poison of the specific disease. An acute specific disease, the virus of which is known to be capable of inducing the degeneration of " parenchymatous " neuritis, may readily excite this state in each of several members of the same family if a congenital tendency to it exists in them. It may readily evoke that which it could, even alone, produce. According to this theory, a tendency to nerve degeneration, acting alone, may lead to the early failure of nutrition of the nerves, while the wasting of the muscular fibres may be either a consequence or a concomitant, in part or altogether. Thus the muscles may atrophy because the nerves have degenerated, or because they also have a tendency to atrophy, or from both causes combined. Nerve and muscle may alike share the congenital imper- fection in some cases, while in others its primary incidence is on the nerves alone, the muscles suffering in consequence of the changes in the nerves. The congenital association may sometimes be even more extensive, and a tendency to the early failure of structures in the central nervous system may be conjoined, giving rise to cases of com- plex aspect and character. It is especially important to note, in this connection, the occurrence of cases that occupy an intermediate position, and combine the characters of this and the myopathic types. Such combined cases are MUSCULAR ATEOPHY. 597 usually partial only, but sucli partial cases, when combined, ultimately cover the whole intermediate ground. For instance, the condition of the legs in the " peroneal type " has co-existed with that of the arms in the "juvenile form" in several recorded cases.* Thus the possibility must be recognised that the cases of this type vaiy, even more than their characters suggest, in the degree in which the morbid tendency acts upon nerve or muscle, or both, as well as the degree in which its activity is spontaneous or induced. Hence the cases may here be only partly out of place — some, perhaps, not at aU ; and their position, as forms of " neuritis," might be equally open to exception. The progressive character of the cases of this type is commonly pro- nounced ; and, even if slow, it renders the prognosis gloomy, and the scope for treatment small. So far as anything can be done, it is by the measures already mentioned in the account of the treatment of the maladies to which the cases approximate, the primary diseases of the nerves on the one hand, and of the muscles on the other. Family Poem op MusctriiAE Atrophy in Childeeit with Spinai. Lesion. The above seems to be the most suitable title for a series of cases described in recent years by Werdnig f and Hoffmann J in Grermany, and Bruce and John Thomson § in this country. The condition is marked by the occurrence of similar atrophy in more than one member of the family, although in Bruce and Thomson's case the condition was an isolated one. It is characterised by the onset of weakness, especially in the hip and back muscles, about the age of from seven to twelve months, in children previously healthy. The weakness gradually impairs and finally abolishes the power of walking, and similar weakness usually attacks the upper limbs as well as the legs, and even the small muscles of the hand may be affected. The condition is one of marked atrophy without sensory impairment, although in one case there was a curious insensibility to the pains of faradic stimulation of the affected muscles. In many of the muscles the reaction of degeneration may be present, and occasionally bulbar symptoms are superadded. 1'he condition culminates in one of extreme helplessness, with marked wasting of muscles without any fibrillary twitching, although death did not take place in some cases until the age of six was attained. No hypertrophy has been noted in any case. * JE.g. by Hoffmann, 'Berlin, klin. Wochenschr.,' 1887, No. 22; and Eisenlohr, *Neur. Centralbl.,' 1889, p. 565. t 'Arch. f. Psych ,' 1891 and 1894. X • Deutsch. Ztsch. fiir Nervenheilk.,' 1893 and 1897, § 'Edin. Hosp. Reports,' 1893. 598 SPINAL CORD. The conditions found after death were marked atrophy of nmscular fibres, although occasionally some fibres were hypertrophied. Atrophy also of nerves and anterior roots was found, and wasting of the cells in the anterior horns. The latter was distinct, and this, with the absence of any hypertrophy at any time (although one child had been noted as very fat which afterwards became much wasted), marks off the cases distinctly from those of pure muscular dystrophy. The type possibly, like the peroneal, forms a connecting link between cases of spinal pro- gressive muscular atrophy and those of true myopathy without any spinal lesion. The presence of definite changes in the cells of the anterior horn and the anterior nerve-roots connects the cases with the former, while a connection with the latter is formed by the simple wasting vrith occasional hypertrophy of isolated muscular fibres, and by the occurrence of the disease in more than one member of a family. Diagnosis. — The age at which the disease occurs, the absence of fibrillary twitching, and the early suppression of the reflexes, as well as the frequent occurrence of more than one case in the same family, will suflEciently distinguish these cases from ordinary progressive muscular atrophy. On the other hand, the absence of any hyper- trophy, the affection of the small muscles of the hand, and the occasional presence of bulbar symptoms will mark them off from cases of true muscular dystrophy. In every case which comes under notice hypertrophy in some muscles, especially the infraspinati, should be carefully looked for, as it may turn out that the cases are more closely connected with myopathic cases than is as yet apparent from the evidence. Pbognosis. — This seems to be extremely bad ; the cases go on from bad to worse, the weakness becomes greater, the atrophy more pro- nounced, until death occurs. But, as has been stated above, this has not unfrequently been delayed as late as the sixth year. Treatment. — The nature of such cases, indicating as they do an inherited tendency to early death in the muscular fibres and their correlated nervous structures, precludes the hope of successful treat- ment. The administration of strychnia hypodermically is indicated, although the age of the patient renders extreme care necessary in the choice of doses. It is also possible that galvanism, combined with massage and passive exercise, might have a beneficial effect. And, of course, care must be taken to ensure wholesome and judicious feeding and satisfactory hygienic conditions. Periodic Family Paralysis. Under this name Goldflam * has described a condition of which examples had been previously published by Westphal, Cousot, and Schachnovdtsch. It is characterised by recurrent paralysis commencing • Berlin Congress, 1890; 'Neur. Cent.,' 1890, p. 638. MUSCULAR HYPERTROPHY. 599 usually in the legs, involving also the arms, and passing off in the reverse order after a period varying from twenty-four hours to three days. During the attack of paralysis the patient is sleepy, but there is no impairment of consciousness, sensibility is retained, and the paralysis is flaccid, with diminished knee-jerks and loss of plantar reflexes. Speech and swallowing are not interfered with. In Gold- flam's case there was great diminution of faradic irritability in the upper limbs, and complete loss in the lower limbs. After the attack had passed off the nerves in both arms and legs reacted normally. Eleven members of the family suffered from similar attacks of paralysis. They began between fiiteen and twenty, and increased in number as age advanced, although the individual attacks did not last so long. In the patient whose case is particularly described there were only two attacks in the first year, but after three years they occurred every fortnight. The condition as regards etiology is obscure. Groldflam's opinion is that it is the result of auto-intoxication — a view which is favoured by the fact that m his patient obstinate constipation persisted during each attack of paralysis. Apparently the disease does not in any way tend to shorten Hfe, but treatment is of little if any effect. Mttsculab Htpeeteopht. The occurrence of a true hypertrophy of muscles, as a condition of disease, is exceedingly rare. In most cases in which the muscles are enlarged, the increase in size is due to a growth of interstitial tissue, fatty or fibrous, such as has been described in the chapter on pseudo- hypertrophic paralysis. We have seen that muscular fibres larger than normal have been described in that disease, and also in some cases of simple atrophy. When this increase in size has been met with only in excised fragments, it is possible that the condition may have been due to a vital contraction excited by the process of excision, and such evidence of hypertrophy is certainly inadequate ;* only when. * Since the above was written, the doubt there expressed has been confirmed by an observation made for me by Dr. H. R. Spencer. A fragment of the gastrocnemius of an amputated leg was excised immediately after the amputation, and the fibres were compared with those of the muscle twenty-one hours later. In order to ascertain more definitely whether a vital contraction persisted as an apparent increase in size, a part of the excised fragment was separated and faradised. The average size of the fibres in the muscle was i^^ inch, in the fragment excised g-i-g- inch, in the fragment faradised -^^j- inch. Since the division of the nerve during the amputation may have caused some contraction, it is possible that the dilference in size produced by excision may be even greater than these figures represent. [I leave the above note unchanged because, since it appeared in the first edition, the observation and doubt have been fully confirmed by various observers, e.g. by Oppenheim and Siemerling, 'Med. Centralbl.,' 1889, No. 39.] It is inte- resting, however, to note that enlarged muscular fibres have been found in the atrophied muscles in infantile pnralysis. 600 SPINAL CORD. it is found after death, can its occurrence be regarded as beyond ques- tion. ISTeTertheless true liypertropliy of fibres is a change tbat may be expected to be occasionally met with in cases that are due to a con- genital tendency, and its presence, even in muscles that are the seat of atrophy, need, therefore, excite no surprise. It was met with by Bruck in a remarkable case of general muscular enlargement in an idiotic child, in whom it apparently developed after birth. The affec- tion first showed itself in the tongue, but the muscles presented spasmodic contractions, and the case, like most of the kind, was evidently anomalous in its features. Muscular hypertrophy has been found in the singular malady described in the next section (Thomsen's disease). It has also been met with, in very rare instances, as a wide-spread or partial condition, usually associated, strange to say, with either diminished power or with a morbid readiness of fatigue.* The muscles most frequently affected have been those of the shoulder and upper arm, or of the thigh and calf, on one side or on both. It has also been observed in the glutei, spinal muscles, and trapezii. The causes are obscure, but it has been ascribed to over-exertion. The diameter of the fibres has been increased to double the normal, a maximum of -^-^ inch having been met with (Eulenberg) , whereas the normal maximum may be taken as -^^ inch. An increase of the nuclei has been observed, without any overgrowth of the interstitial tissue. The condition is manifested by an increase in the size of the muscles, which are also firm. The circumference of the limb is greater than normal, and when the change is unilateral the difference between the limbs of the two sides may be very striking. The maximum circumfer- ence of the calf has been as much as seventeen inches. The muscles are soon exhausted, and have been weak in some cases, while in others there has been abnormal strength for brief exertion. The electrical, mechanical, and myotatic irritability of the muscles has usually been found unaltered. The disease may be suspected if a marked increase in size in an adult is accompanied by impaired power of sustained exertion, if the muscles are firm, and the patient does not manifest other indications of pseudo- hypertrophic paralysis. The diagnosis can, however, only be made with certainty by the microscopical examination of an excised fragment, and even then subject to the reservation mentioned on the previous page. The meagre facts regarding the course of the disease suggest that it usually persists without getting either better or worse. Treat- ment appears to have but little influence upon it. A smgular case has been reported by Eulenberg,t which differs in * Auerbach, ' Virchow's Archiv,* Bd. liii, pp. 234 aud 397; Berger, 'Deut. Archiv f. klin. Med.,' Bd. ix, 1872, p. 363 ; Friedreich, *l7eber Prog. Muskelatrophie,&c.,' 1873; Eulenberg, ' Real-Eiicyclopadie,' Bd. ix, p. 354. A very aimilar case is described by Pal, ' Wien. klia. Woehenschr.,' 1889, No. 10. t ' Deutsch. med. Woehenschrift,' 1885, No. 12. thomsbn's disease. 601 many particulars from the form of disease above described, and illustrates the complex relations of enlargement of the muscular fibres and its connection with degenerative processes. A man aged thirty- six presented an enormous enlargement of the muscles of the left leg, which were soft and flabby and weak, with lowered irritability. The condition had slowly developed after a fall on the back at ten, which caused imperfect paraplegia, motor and sensory. A year later, during pleurisy, he had thrombosis of the left femoral vein. In an excised fragment of the gastrocnemius the muscular fibres were large, the maximum being -^-^ of an inch ; they presented fatty and vitreous degeneration, and fat was seen between the fasciculi. The muscles of the other leg were somewhat wasted, but the fibres were also enlarged and degenerated. It would appear as though the condition had resulted from a traumatic lesion of the spinal cord, and had been intensified in the left leg by the influence of the thrombosis and resulting vascular disturbance. THOMSBN'S DISEASE; MYOTONIA CONGENITA. The malady thus designated may be considered here, notwith- standing the obscurity of its nature, because it agrees with the diseases last described, in that the symptoms are muscular, and that the disease seems often congenital and occurs in families. It has been named after the physician whose description gained for it general notice, and who is himseK its subject, but it had been previously described by Leyden, and hinted at, long ago, by Sir Charles Bell.* It is not always congenital, and " Transient Myotone " would be a more exact name. The disease is characterised by a peculiar rigidity of the muscles, which comes on when they are first put in action after a period of rest. The rigidity is transient, and when it has passed off, it does not return * Bell's * Nervous System,' Case 184, p. 436. The objections to cognominal nomenclature of disease are certainly i-educed to a minimum when the first describer of a rare disease is also its subject. The most important papers on the disease are those of Leyden, ' Klinik der Ruckenmarkskr.,' 1874, Bd, i, p. 128 ; Thomsen, 'Arch. f. Psyehiatrie,' Bd. vi, 1876, p. 702, also ' Centralbl. f . Nervenkr.,' 1885, p. 193 ; Bernhardt, 'Virchow's Archiv,' Bd. Ixxv, 1879, p. 516, and 'Centralblatt f. Nervenkr.,* 1885, p. 122; Ballet and Marie, 'Arch, de Neur.,' 1883, No. 13; Mobius, • Schmidt's Jahrb.,' Bd. cxcviii, 1883 ; Ringer and Sainsbury, ' Lancet,* 18S4, pp. 767, 816, and 860 ; Erb, ' Die Thomsen'sche Krankheit,' Leipzig, 1886, also *Deut. Archiv f. klin. Med.,' 1890, xlv, p. 529; Self ert, ib., xlvii; Marie, in ' Eucycl. des Sc. Med.,' 1886 ; Hale White, * Brain,' April, 1886, and ' Guy's Hosp. Rt'p.,' vol. xlvi (a very valuable paper, with bibliography) ; Jacoby, Journ. of Neur. and Ment. Dis.,' 1887, xiv, p. 23 j Jolly, • Siidwest. Neurol^* Baden, June, 1890; Buzzard, ' Lancet,' 1887. G02 SPINAL COED. as long as exertion is continued. Tlie malady is often hereditary, and usually affects several members of the same family. In that of Thomsen, cases can be traced through five generations. It appears to be more common in Scandinavia and Germany than in France or England, but it is a rare disease ; * and although a considerable number of clinical cases have now been recorded, there has been no post-mortem examination. There is little to attract attention in the slighter forms, and the rarity of these may Tiltimately be found to be less than at present appears. Both sexes suffer. In most cases the symptoms have been first noted in childhood, between four and ten years of age, sometimes even in the cradle. They increase during the period of muscular development, and then remain stationary. A few patients have seemed free until about the period of puberty, but even in such in- stances it is probable that the tendency was congenital in origin, since the cases occurred in families, other members of which suffered earlier. But in a few cases symptoms apparently identical with those of the congenital disease have come on in early manhood after some exciting cause — in one case a lightning stroke, in another a sudden, alarm. t Severe and prolonged exertion during two years preceded the onset of very characteristic symptoms in a man of twenty-five, without heredity. J In such cases the disease has been apparently acquired. The characteristic symptom is tonic spasm of the muscles when they are put in action after a period of rest. As soon as the patient attempts to move, the muscles become rigid. The rigidity may make movement impossible while it lasts, or may merely lessen the possible range of movement. After a few minutes, or less, the spasm passes away, to be renewed, but in slighter degree, by a fresh attempt. If the movements are continued, the spasm soon becomes trifling, and does not retiirn until after a period of rest. The longer the rest, the more troublesome is the spasm. The subject can walk for hours without fatigue when it has passed off. The rigidity is sometimes lessened by alcohol and increased by attention and by fear of it ; the more the sufferer tries to overcome the stiffness, the less is he able to do so. It is also worse in cold and damp weather. In a severe case, a slight impulse will make the person fall, and it may then be impossible for him for some minutes to rise from the ground. The arms are usually less affected than the legs, but in some cases the rigidity fixes the fingers for a short time on an attempt to use the hand. The muscles of the face are usually free ; mastication may, however, be iaterfered with by the spasm in the muscles of the jaw. Earely, the * In England cases have been observed by Buzzard, Herschell, Hale White, Benham, Chapman, and others. t Engel, ' Phil. Med. Times,' 1883, p. 412 ; Scbonfeld, * Berlin, med. Wochenschr.,* 1883, No. 27. X Moyer, ' Med. News,' 1890. thomsen's disease. 603 tongue or farv* has been affected ; still more rarely the muscles of the eyeball, interf *^ring with its movement and retarding the descent of the upper lid.* Most voluntary muscles, indeed, seem liable to suffer, even the musoles of the larynx and pharynx ; those concerned in the processes of respiration, defaecation, micturition, and coitus have also been involv loped, and a cavity due to imperfect con- ^ traction of the canal. The change is Pia. 183.-Central canal in ^^^ confined to the posterior half of normal cords. It has the rorm or '' -"^ a transverse slit in A, a vertical the cord, and usually to the postenor slit in C (from the conus medul- columns, which, as we have seen, are laris), while in B it is circular. » i i j. xx i t. In each it is lined by columnar formed last. It may, however, be pre- epithelium and surrounded by sent in one or both posterior horns, in cellular elements, rounded, or ^j^gj^ cavities also may be formed. The angular trom compression, . . i i ";• mingled with granules. In D, persistent embryonal tissue may be evi- wbich is from the same spinal dently increased by a process of various TntlT. ^;c!;;irbf.°l'Bsol degrees of growth, and the cavity enlarged nuclear tissue. by distension. Further, when the persis- tent tissue is considerable in quantity it may break down, and thus give rise to a new cavity, or enlarge that which has developed from the primitive canal. Thus the cavity may be distinct from the canal, and in some cases the abnormal tissue around it is very small in amount, and reduced even to a mere wall. It may also be separate, because it is the hinder part of the embryonal canal, cut off by coalescence of the walls. SYKINGOMYELTA. 631 These conditions are shown very well in the adjoining figures, after Leyden (Figs. 184, 185). In the first, at a, the cavity presents nearly the shape which it has at one period of development, before the formation of the posterior columns is completed, and without Fig. 184. — Syrln/ ^--^ ^ differences, but the resemblance is suffi- ciently close, and the origin of the differ- ences is sufficiently clear, to make it prac- tically certain, as already mentioned, that the two forms are really the same, and that the form met with in adults is the congenital condition, persisting until later life. Of the characters which this form has in common with the congenital disease, the most important are the position of the cavi- ties and the presence of tissue in their vicinity of embryonal or gHomatous nature. The differences depend on an apparent /^ \ increase of this tissue by a process oi / t growth, on the greater damage to the other |, J parts of the cord by the distension of the \( cavity, and on the extent to which the for- ^«- U mation of new cavities or enlargement of Fn*. 185. — Synngomyelia, old ones takes place by a process of disin- from a child nge.l two and a tegration of the newly formed or persistent hiiltyears, with internal liy- .^ "^ -^ _ drocephalus and absence of tissue. The damage to the cord produced cerebellum. (After Leydeii, by distension of the cavity involves most IxTiig^'A! B.^cervical^e- *^® ^^^^®^ ^'^^ ^^^^ resisting parts. The gion ; gelatinous (embryo- grey substance, therefore, suffers in greatest Qal) tissue in the posterior degree ; the white columns to an extent eolumns encloses a medial , . cavity, lined in places with that depends m part on the precise posi- cylindrical epithelium, and tion of the cavities, as presently to be de- l:t'tt'?:S:„7''S! -rfted. me kte aI.o present, ia many lower dorsal j in each poste- cases, the complicating changes of second- rior column IS a mass of ^^^ degeneration, ascending or descending, similar gelatinous substance •' , ° . —.. nn,^ i j ji (which, by a mistake, is as shown m Eig. 186, due to the com- shMwn in C as an open pression of certain tracts at some specially cavity). In D, lumbar „f|:„„x n . region, this tissue occupies ^-nectea spot. only the position of the pos- As the simplest condition, we maj terior median columns. -^^^^ ^ dilatation of the Central canal surrounded by gliomatous tissue disposed as in congenital cases. This tissue is often more abundant, and forms a more distinct SYEINGOMYELIA. 633 mass, lower down the cord, below the cavity. A good example of tliis condition in slight degree is presented b\ the cord, the seat of chronic myelitis, represented at Fig. 109, p. 385. In the cervical region (a) there is a large central canal, bounded by a thick layer of gliomatous tissue. In the inner part of this tissue, limiting the cavity, is a sinuous membrane, fibrous in structure. The origin of this membrane is not easy to explain, but it is often found in cavities of this character, and is evidence of the similar nature of those that differ much in other respects. In the lumbar region (b) the tissue, which bounds the cavity ia the other section, forms a large round mass in the posi- tion of the canal, obliterating it. When a central cavity ap- pears not to be the canal itself, but to be situated behind, it is then apparently often due to a persistence of the fore-part of t^s posterior portion of the canal, after the posterior com- FlG. 186. — Syringomyelia, from a case of tumours of the pons and Cauda equina, with some diffuse ^^ '^ Bcleiosis in the dorsal region of *%v' the cord. A, B, and C are sections "^^ ' of the cervical enlargement. The -il--'' 'Z' large cavity iu A is perhaps the •%;^-^- dilated canal, since it is lined in W/ £• front with epithelium, but in front of it, in the posterior commissure, is a group of nuclei like an obliterated canal. The zone of tissue around the cyst is composed of interlacing fihres and nuclei, and processes extend from it into the posterior columns both in front and behind. In B the cavity is smaller and the wall thicker, while in C the tissue about it forms a considerable mass, and a second small cavity has formed in the middle line, apparently by the brenking down of the tissue. In the dorsal region (D) there was merely an unusually large accumulation of nuclei in the position of the canal, which, in the lumbar region, bad the normal aspect (E)." The cord presents degeneration of the right pyramidal tract (descending from the tnmour in the pons), and of the post. med. cols, and ant. lat. ascending tract, pro- bably ascending from the sclerosis. 634 SPINAL COED. missure has been formed. In Fig. 186, for instance, we have a central cavity, but in the commissure in front of this is a mass of nuclei having the usual aspect of an obliterated canal.* The cavity is surrounded by a zone of tissue, which in a and b sends off a fringe of processes, especially backwards. This tissue is increased in the lower part of the cervical region (c) . In b a small cavity is formed between the tissue and the grey matter by breaking down, and in c another exists in the middle line behind the growth, probably due to deficient closure of the original fissure, and increased by a destructive process, Still lower, the commissure resumes its normal appearance, but the collection of nuclei in the position of the canal is unusually large (d). In the lumbar region the canal is patent (e). The degeneration of the posterior median column and of the lateral columns is secondary. We have seen that in the congenital cases we must recognise a process of growth of the persistent embryonal tissue to account for some of the conditions met with, and a like process is suggested by the central mass in Fig. 109, b. Hence it is not surprising that in. many cases the growth should attain the dimensions, and assume the characters, of a positive tumour. In most cases the tumour has been central in position, and has had the structure of a glioma. It has occupied a large part of the area of the cord at a certain level.f In the chapter on the tumours of the cord it has been pointed out that sarcomata also may grow from the tissue around the central canal, as in the case shown in Fig. 181. Hence it is not surprising that the condition of syringomyelia, even if this is congenital in origin, should be frequently associated with definite tumours. The growths have often been multiple, apparently the result of a wide-spread tendency, and perhaps connected with a wide-spread persistence of embryonal tissue, of which remarkable instances are sometimes met with. In the case shown in Fig. 186 there was a tumour of the pons and also one of the cauda equina. The nature of the growths is uncertain, but they were probably either sarcoma or glioma. The same tendency to morbid growths is illustrated also by Fig. 187, which is similar in many respects to that just considered. In this case also there was a tumour of the pons and one of the cauda equina, and there was also a central growth in the dorsal region, occupying the greater part of the area of * This is the probable interpretation. At the same time it is possible that the auclei have not this significance, and that it is really the central canal. It is often more ditficult than might be imagined to say whether a cavity does or does not represent the central canal. The presence or absence of an epithelial lining has generally been taken as a criterion, but it is doubtful whether this has any signifi- cance. Around the whole of the original cavity the inner layer of cells is arranged as an epithelium, and if any part of it persists it is probable that epithelium will persist also. Moreover the epithelium often disappi ars from the wall of the dilated central canal itself; always where it is enlarged by breaking down of tissue. f As in an interesting case described and figured by Riesinger, 'Virchow'a Archiv,' Bil. xcviii. SYRINGOMYELIA. 635 ^ the cord, to wliich the ascending degenerations were secondary. In a there is a large central cavity which is probably not the ceutr.J canal, since, as in the last figure, the position of this is marked by the oval group of nuclei in the anterior part of the grey commissure. The zone of tissue which bounds it is i narrow, but a few processes are given off behind. In b, first dorsal, this tissue forms a compact mass, and the pro- cesses are numerous and very similar to those in the last figure. In c the commissure is reduced almost to normal conditions. In this cord we have also an instance of the fact that cavities may occur in other parts, very similar in their general characters to those that occur in the central region. In b a large cavity occupies the intermediate grey matter and posterior cornu on the right side, with some morbid tissue bounding it on the medial side. In c the cavity is smaller Fig. 187. — Syringomyelia, from a case in which there were tumours in the dorsal region of tlie cord, the camla equina, and the pons Varolii. A, mid-cervical region. A large oval cavity lies behind the grey commissure, surrounded by a narrow wall, chiefly composed of fine fibres, but with a wavy membrane on the inner surface. In front of the posterior commissure, an oval group of nuclei has the aspect of an obliterated central canal. A few short processes extend from the wall of the cavity into the posterior columns. There is secondary ascendino: degeneration of the post. med. cols., right direct pyramidal tract, and ascending antero-lateral tract in all the sections. B, first dorsal. Behind the posterior commissure is a growth consisting of small cells, round and fusiform, the latter with round nuclei. It contains many vessels with thickened walls. A fringe of fine processes extends trom it into tlie posterior columns. An irregular cavity occupies, on the right side, tlie posterior half of the grey matter, which is reduced to a narrow layer around the cyst. This is lined by a delicate nucleated membrane, outside which is a thicker membrane, lying in folds, the section of which is thus sinuous. Out- side this again is a small-celled growth similar to that behind the commissure. In C, a little lower, this cavity is smaller, the sinuosities of the wall greater, and the growth outside it more abundant. (Still lower the area was entirely occupied by the growth.) In the posterior commissure there is only a quantity of loose nucleated tissue in the situation of the growth.* * For the opportunity of drawing these sections I am indebted to Dr. Dreschfeld, A full account of the case has been published by Dr. Harris in 'Brain,* Jan., 1886. The large growths were sarcomata. 636 SPINAL CORD. and the tissue around it is more abundant, but easily distinguish- able from the grey substance, while a little lower down the cavity disappeared and the tissue formed a compact rounded mass. The cavity is lined by a delicate layer of cellular mem- brane; outside this is a fibrous membrane, lying in folds which appear as sinuosities in the section. The existence of thia membrane shows that the cavity is not simply formed by the breaking down of the tissue. The tissue is quite similar in structure to that which is behind the commissure in b.* The posterior cornu is not an uncommon seat of cavities, which may extend through the whole length of the horn. An example of this is shown in Fig. 188. Haemorrhage had occurred into the cervical region of the cord (a), which was enlarged and distended with blood, so that the precise character of the cavity in this region was indis- tinguishable ; the blood also filled the cavity through the * In connection with the tumour of the Cauda equina in these two cases, it may be mentioned that the same coincidence has been observed in other instances. There was a tumour in that situation, for instance, in the case de- scribed by Riesinger, who rightly re- garding the condition as congenital in origin, suggests that the tumour may be connected witli the fact that \j '^' the embryonal cord occupied the entire ^ ~ ■ length of the canal. Fio. 188. — Sections of a spinal cord in which a cavity existed throughout its length. HsBmonhage in the cervical region was the immediate cause of death. The extra- vasation had there distended the cord (A), and had bnrst into the cavity, which was filled with blood. A smaller cavity existed in the right cornu, in the upper dorsal region (B). In most parts the inner surface was slisrlitly irregular, as if pro- duced by breaking down of the tissue, but near the position of the central canal a sinuous membrane existed in places, without, however, any epithelial covering. SYRINGOMYELIA. 637 entire lengtli of the cord. In the upper dorsal region (b) there are two canities, one in each posterior cornu, but that on the right ceased a little lower down, while the other extended to the lumbar region, as shown in the figure, reaching almost to the surface of the cord. The upper and inner extremity of this cavity is in the position of the central canal, no other trace of which exists. There is some abnormal tissue in the neighbourhood of the commissure, and also in c, where irregular tracts pass transversely from the median septum into the fore-part of the posterior columns. The presence of this tissue, and the relation to the central canal, suggest a congenital origin. During the reduction in size of the canal, in the development of the cord, the cavity presents at one period short lateral processes, and we can therefore understand how a still earlier arrest of develop- ment may lead to the persistence of a lateral process on one side or both, sui'rounded by residual embryonal tissue, and that the cavity should afterwards extend in this tissue or in the grey matter by a process of growth and disintegration, such as probably had occurred in Fig. 188, D. A comparison of d and e suggests that the two cavities were imited in the middle line in the upper part of the cord, where the haemorrhage took place. In the conditions we have hitherto considered, definite limited regions of the cord have been involved through a considerable vertical extent. The changes are sometimes, however, much more diffuse in their dis- tribution, as is shown by the remarkable lesions represented in Fig. 189. In this cord, which is that of an adult, we have a combination of the same two conditions of abnormal tissue and cavities. Scattered through the nerve- sub stance are tracts of a peculiar tissue, represented by the darlver shading of the figure, and in many regions thus affected there are cavities, for the most part fissure-like, as if the cord had been split here and there. At first sight the appearance suggests an active and recent morbid process ; nevertheless I think that the congenital origin of the condition is beyond doubt. It will be observed that the morbid changes, as in the otter forms of syringomyelia, are chiefly m the posterior half of the cord ; small areas of disease in the anterior columns, in the sections b and f, are the only exceptions. The minute structure of the abnormal tissue was exactly like that of the normal gelatinous layer beneath the pia mater. Besides the conspicuous areas figured, it could be traced here and there, in small tracts, through the whole of the posterior columns and the hinder parts of the lateral columns, and also in the posterior horns, in the grey matter of which it could be readily distinguished. The relation of the cavities to this substance is distinct ; where they extend beyond it, this is apparently the result of the distension of the cavities and an actual fissuring of the cord, along the lines of connective tissue, by the pressure of the contained liquid. The medial cavity in c is doubtless due to defective closure of the original fissure between the posterior columns. In the lumbar region the nerve-fibres are absent from the front of the posterior 638 KPINAL COKD. columns, where a coarse network of this residual tissue encloses empty spaces. The damage to the grey matter may entail alterations in the related nerves, and even, in cases of long duration, in those connected with the posterior roots. In the peripheral nerve-fibres of the skin and muscles, changes of the ordinary chronic degenerative character were found by Dejerine in cases in which sensation was altered or the muscles wasted. Thus these various forms of syringomyelia, in spite of their varia- tions in seat and form and general aspect, when closely studied, seem all to be connected with gliomatous tissue ; and that the morbid state takes its origin in abnormal conditions during the development of the cord is practically certain from their seat and features. This lesson is clearly taught by the facts shown by the cases here illustrated. It is probable, therefore, that this conclusion is also true of cavities of similar character and position in which no gliomatous tissue can be recognised ; and most of the hypotheses regarding the origin of such cavities from processes of simple myelitis and the like have no suffi- cient foundation. But we are still ignorant of the mechanism by which the defect in the process of development is brought about. It has been extensively ascribed to an inflammation of the embryonal neuroglia at an early stage of development, but of this there is no real evidence. It is, moreover, no explanation to assume a primary intra-uterine hyperplasia of the embryonal tissue. It is, indeed, possible that more than one morbid process during the early stage of development may cause the condition, and that closure of the canal below may have consequences during development which it has not at a later period. But it is important to recognise the fact that there is a gradation between the chief varieties, and that some are associated with developmental defects ia the brain, to which they can only be related as the common expression of a defect in the develop- mental tendency of the germinal tissue ; and what must be true of some forms is probably true of most. This may seem only to push the difficulty into the region of the inexplicable, but it is only placing the origin of the malady where we are compelled to refer the causa- tion of so many congenital diseases, which, after aU, bear but a small proportion to the physiological characteristics that spring from the same source. From these considerations it is probable that cases of syringomyelia are divisible into two classes : (1) those in which there is a congenital anomaly which may afterwards take on a process of overgrowth as distinguished from development, characterised clinically by very gradual onset of symptoms lasting, it may be, throughout several years ; (2) those in which there is actual central new growth, frequently with cavity formation ; and it may be associated with new growths elsewhere — glioma, sarcoma, syphiloma, — in which the course is a much more rapidly fatal one. The symptoms of the disease have followed some illness, mental SYEINGOMYELIA, 689 bTiocTs: or anxiety, and traumatic influ- ences, but it is probable that in no case bave these done more than excite the manifestations of pre-existing dis- ease, or induce local changes in the morbid state. The possible influence of injury has certainly been over- estimated, since in some of the cases in which it seemed effective the malady was unquestionably congenital, and the traumatic influence only terminated its latent stage.* Syimptoms. — The manifestations of syringomyelia depend on the secon- dary processes of distension and growth, and the damage thus produced to the functional elements of the cord.f * Among the chief papers in which the sub- ject will be found discussed are those of Scliultze (see below) ; Hellich, * Arch. Boheme d. Med.,* 1890, iii. No. 4; Kronthal, ' Neur. Centralb.,' 1888, p. 333 J Oppenheim, ' Charite Annalen/ 1886, p. 409; Hoffmann and Schlesinger, loc cit. t They have been fully described by Schultze, •Zeitschrift f. klin. Med.,* 1888, p. 525; and * Verb. Cong. Inn. Med.,' 188o ; and by Allen Starr, 'Am. Journ. Med. Science,' 1888, vol. xcv. ^. \ ) / V Fig-. 189. — Cavities in the spinal cord. A, mid- cervical, presenting merely some increase of Connective tissue in the left lateral column. In B there are several cavities having the aspect of distended fissures, the largest in the middle line of the posterior columns and the right posterior cornu; smaller ones in the lateral columns. Adjacent to each is a quan- tity of dense tissue, which had a peculiar and uniform structure. It consisted of a very fine network of fibres with minute nuclear bodies in the interstices. No larger cells were observed. Throughout the posterior and lateral columns this tissue could be seen, here and there, thickening the neuroglia, where no conspicuous masses were formed. It could also be traced in the posterior cornu, and was readily distinguished from the spongy sub- stance by its slighter staining. Tlie distri- liution of this tissue is shown in the other sections by the darker shading. In C the fissure in the middle line is narrow. In E and P the anterior part of the posterior columns contained a coarse network of this tissue, and no nerve-fibres. The central can^l w;is obliterated, but the group of nuclei that marked its position eoold bt traced tiiroughouc the cord. 640 SPINAL CORD. Hence the state is sometimes discovered after death, when it has given rise to no symptoms, and its existence has not been suspected during life. In young children, indeed, it appears never to cause any definite symptoms, while the disturbance of function is variable in occurrence and degree — much more so than in character. The central position of the disease entails considerable uniformity in the distri- bution of its local consequences, and hence also in the derangement of function that results from simple increase in the lesion either by dis- tension or growth. Hence the symptoms ai*e often such that they have considerable diagnostic importance, although in a minority of cases they are less uniform in character, probably because the disease is unsymmetrical, or irregular in position or extension, whether the symptoms are due to the distension of a cavity, or to this combined with adjacent growth of tissue. It then often causes symptoms indis- tinguishable from those of a tumoiir of neoplastic nature. Moreover the precise level at which the chief morbid process takes place leads to a corresponding variation in the position, and therefore in the general aspect, of the symptoms it produces. The fact that the lesion is almost always greater at the cervical region causes the arms to be the most common seat of its manifestations, while the occasional inva- sion of the fourth ventricle by the associated growth, and the occur- rence of coincident secondary changes in this part, explain the involve- ment of some of the cranial nerves that has been met with in a few instances. The symptoms are usually of slow development, increasing gradually in the course of years. Their main features are twofold, of which one is clearly and certainly intelligible, while the explanation of the other is a matter of hypothesis, although also not difficult to under- stand, at least in part, if the opinions expressed in the chapter on the functions of the cord are correct. The two leading features are loss of sensibility, chiefly to pain and temperature, and muscular atrophy, resembling in characters that met with in the " progressive " spinal form. Of the two, the sensory loss is the earlier and more constant. The muscular atrophy is a necessary consequence of the damage to the anterior cornua from the compression they endure, when and where the central cavity or adjacent growth attains such a size as to damage them seriously, and they may be reduced to a mere zone between the cavity and the outer ring of white substance. The de- struction of the motor nerve-cells involves the degeneration of the nerves and the wasting of the muscles. The loss of sensation is intelligible if the path of painful impressions is by the posterior comiaissure.* The enlargement of the central canal and disease in its vicinity can hardly fail to damage early and much the fibres that cross at the level of the chief lesion, and constitute the path from posterior roots not very far below. The course of thermal sensations • See p. 224 as to a tract in the grey commissure described by Ciagliuski ('Neur. Ceut./ 1896). STEINGOMYBLIA. 641 is Btfll qmte tmTmown ; the only fact we have — the frequency with which such sensibility and that to pain are involved together — points to contiguity of path, and prevents surprise at the special affection of this form of sensibility in syringomyelia. Tactile sensations are lost only in rare cases ; our ignorance of their path prevents us from ex- plaining the fact, but we know, from other facts of disease, that it is distinct from that for pain. Moreover, the occasional localisation of the morbid process in the posterior columns, and even cornua, may explain the involvement of all forms of sensibility, and also its occa- sional restriction in area, since it may be due to direct interference with the posterior root-fibres after they have entered the cord. In many cases the affection of sensation of pain and temperature is equal ; in others the latter is lost to a greater degree and extent than the former. Its loss is often the earliest symptom, as the scars of burns may show. The loss to heat and cold may not correspond. Thermal or painful hypersesthesia has preceded the loss, as with other forms of sensation when destroyed by processes that slowly damage the fibres, and irritate before they interrupt. Perversion of sensation has been noted, heat being felt as cold, and vice versa. Spontaneous sensations are common, doubtless from the irritation of the fibres in the early stage, or of their upper portions when they are inter- rupted — feelings of heat or cold, and in some cases pains, various in character, sometimes paroxysmal like neuralgia, or sharp and brief like those of tabes, and occasionally referred to the joints, or felt chiefly in some part adjacent to the seat of the other symptoms. Pain in the spine may be complained of, and is, perhaps, a direct effect of the disease. Cramps also and shooting pains sometimes occur. Often the malady causes no suffering. The loss of sensation is usually sharply limited, and the arms or upper half of the trunk are its common seat. It is usually found in the same part as the mus- cular wasting, but is more extensive, especially below the seat of atrophy. Thus, when the muscles of the shoulders and upper arms only are wasted, the sensory loss may be in the forearms and hands. This we should expect from the fact that the crossing of the sensory path is some distance above its entrance into the cord, while the motor roots arise from nerve-cells mostly near their level of exit. Exceptions may be due to the affection of the root-fibres, as explained above. Further, the fact that the distension and damage always extend through a considerable vertical area of the cord makes the relation Vf the two sets of symptoms more extensive and less regular than if the disease were limited to a small region. The " muscular sense " is said to have been generally normal when tested. Occasionally there has been unsteadiness on standing with the eyes closed. The motor symptoms usually come on after the sensory loss, long after in slight cases, and consist in muscular weakness and wasting in the upper limbs ; while, if the legs suffer, it is generally from simple VOL. I. 41 642 SPINAL CORD. spastic paralysis, such as would result from, and is no doubt due to, compression of tlie pyramidal tracts by the disease in the upper part of the cord. It is rarely complete. The unsteadiness of move- ment above mentioned we may connect with the tendency of the lesion to involve the posterior columns, and so probably to inter- fere with the path from the muscles to the cerebellum. Earely there is atrophy of the legs similar to that of the arms, and in such cases the disease extends into the lumbar enlargement. Eeflex action in the legs varies according to their state ; it may be normal or increased : the knee-jerks are often augmented, with rectus- and foot-clonus, or, in the cases last mentioned, myotatic irritability may be lost — very rarely on one side only. A curious tremor of the limbs has been noted in some cases. The muscular atrophy in the arms begins in and. chiefly afEects certain parts, according to the position of the greatest damage to the grey matter of the cord. It may be in the hand and region of the alnar nerve, or in the muscles supplied by the musculo-sjjiral and radial nerves, or in the shoulder and upper arm muscles.* It is a slow wasting, with gradual lowering of the electrical irritability, as in progressive muscular atrophy, although, as in that disease, some groups of muscles may present indications of the reaction of degene- ration in the early stage of their affection. Fibrillation is common. As the wasting and weakness increase in the part first affected, they spread to others, to the rest of the limb, and to the adjacent parts of the trunk. Weakness of the trunk muscles often leads to lateral curvature of the spine ; and the convexity, owing to posture, is usually to the left. The occurrence of similar symptoms in the legs is ex- tremely rare. Both sides usually suffer together ; a unilateral affec- tion has indeed been observed, but is altogether exceptional. The sphincters may escape or be involved. Trophic disturbances in the extremities affected with sensory loss are not uncommon. The skin may become thin and glossy, or thick and homy. Acute changes may occur — eczema, herpes, or bullae ; whitlows; deep, obstinate ulceration, and even gangrene. More frequent, however, is simple vaso-motor disturbance, coldness and lividity of the extremities, or redness with swelling and heat, and sometimes a tough oedema, which may be local like a tumour, and afterwards pass away. The nails share the trophic changes in the hands, becoming grooved, fissured, and cracked ; they may even drop off. The secretion of sweat is lessened in the part, as was well marked in one unilateral case,t or it naay be increased. The action of pilo- • Blocq thinks that spastic paraplegia is chiefly met with in the CHses in which the atrophy begins in the region of the ulnar nerve, and tabetic symptoms in the legs when it begins in the radial area ; but the data for the generalisation need to be Tnore extensive. t Allen Starr, 'Am. Journ. Med. Sc.,' May, 1888; Rumpf , • Neur. Cent.,' 1889, p. 257. SYiilNGOMYELIA. 643 carpine lias been fotincl to be delayed, altbotigb ultimately increased (Gri-asset). The bones may become thickened or brittle, and joint changes (Charcot's joint), like those of tabes, sometimes occTir.* It is not common for the symptoms to extend into the region of the cranial nerves, although in occasional cases various disturbances of function have occurred, presumably due to the extension of the changes into the medulla and pons, and chiefly met with vfhen there is upward extension of the associated growth, already mentioned. Thus there have been paralysis of one vocal cord, or of both, of the tongue, the palate, and of the face, difficulty in swallowing, disorder of respiration and of the heart's action. Taste and smell may be affected, and there may be sensory impairment in the face. Certain disorders may occur in the eyes, probably due to disease of the path of the sympa- thetic in the cord, or to that of the fourth ventricle. Thus the pupils are often imequal, the smaller being on the side of the more severe cord symptoms, on which the fibres for the radiating muscle of the iris are likely to be damaged. Narrowing of the palpebral fissure and slight ptosis have been also noted. Nystagmus is not rare.f The course of syringomyelia is, as a rule, slow, and measured by years, although an apparent exception is presented by the cases in which it is associated with spreading overgrowth of the adjacent gliomatous tissue, or in which acute destructive processes occur in this and spread to its vicinity. In such cases a considerable development of the disease may be attained before symptoms are produced, and these may rapidly reach a considerable degree, and cause death in a few months or even less. In most cases death is the result of exhaustion, of the impairment of the functions of the medulla, or, more com- monly, of some complication — bedsores, cystitis, and the like. Diagnosis. — The resemblance of the disease to more common maladies led to its confusion with them during life, until the careful observations of the last few years have established features by which its existence can often be at least surmised. The most im- portant characteristic is the combination of muscular atrophy with gtUl earlier sensory loss, involving temperature and pain far more than tactile sensibility. But the occasional implication of all forms of sensation must be kept in mind, and also the fact that in slight and slow or anomalous cases the sensory symptoms may long predomi- nate, and for a time exist alone. The position of these symptoms (in the arms), and their frequent combination with spastic palsy in the legs, is a further characteristic — not, however, unequivocal. Cervical pachymeningitis causes symptoms which, in general * Nissin, *Arch. f. klin. Chir.,' Bd. xlr; * Neur. Centralb.,' 1893, p. 100; Sokoloff, * Deutsch. Ztschr. f. Chir.,' Bd. xxxiv; *Neur. Centralb.,' 1893, p. 101; Galloway, ' Lancet,' 1891, vol. i. t Contraction of the fields of vision, especially for colours, has h'en observed, but ■ not easy to explain (Dejerine and Turland), 644 SPINAL COKD. character and in distribution, alike in tlie arms and fhe lerjs, very closely resemble those of syringomyelia ; but the affectioii runs a more rapid course, the anaesthesia involves all forms of sensibility, and has not a greater but a less estent than the muscular ■wasting ; the two correspond more closely in their seat ; pain is a far more prominent symptom, and the reaction of degeneration is common in the wasting muscles. Tumours of the spinal cord only cause symptoms of like character, and especially of similar symmetry, when they are central in situation, and the diagnosis may then be very difficult and even impossible. But the resemblance is often more than superficial, for such growths generally arise from residual gliomatous tissue, and are such as are frequently associated with syringomyelia. It is chiefly from the more rapid development of symptoms, and their more speedy extension, that such a growth can be suspected; and only the presence of slighter chronic preceding symptoms of the character above described would justify the expecta- tion that a cavity is associated with the growth. Progressive muscular atrophy is sufficiently distinguished by the absence of impairment of sensation, and in peripheral neuritis the pains, mode of onset, and degenerative reaction in the muscles should preclude any danger of mistake. In " Morvan's disease," to be pre- sently described, the symptoms may bear a close resemblance to those of syringomyelia, and it is probable that they are due to a similar condition of the spinal cord, so that it is to be recognised merely as a variety of syringomyelia. As a rule, however, the early loss of tactile sensibility, and the greater prominence of trophic disturbance in the tissues, especially the painless whitlows, enable the diagnosis to be made. There is only one acute affection of the cord that enters into the diagnostic problem, and that is spinal haemorrhage. It has been mentioned in the account of this condition that the haemorrhage is sometimes into a pre-existing cavity — as in the case shown in Fig. 188. The presence of a cavity into which the blood has been effused may be suspected if the haemorrhage has been preceded by any symptoms suggestive of syringomyelia, inquiry for which should always be made ; or if a rapid extension occurs through a consider- able vertical extent of the cord, distinctly abolishing its central mnctions. The malady, however, varies much in seat and characters, as is evident from even a cursory glance at the illustrations given above; the symptoms, of necessity, vary with the lesion. The diagnosis may be difficult and even impossible in such cases, especially in the early stages and slighter forms, when irritation and pain predominate, and even neuralgia may be simulated. It may be necessary to wait for time to show the course of the symptoms. Their progressive increase, in spite of variations, should always be taken into account; it fre- quently is the first feature that suggests the nature of such a disease, contrasting, as it does, with the tendency of inflammatory affections ANALGIC PANAEITIUM, 645 to arrest and improvement. A peculiar difficulty is presented by the cases, not few, in which the first symptoms follow some influence — an illness, a blow, or even mental disturbance — that seems to be their cause, and suggests disease of very diif erent nature. Often then, also, it is only by waiting and watching that a right opinion can be formed. When bulbar symptoms come on rapidly, the nature of the case can only be inferred from previous spinal symptoms. The Prognosis and Treatment of syringomyelia are subjects on which, lanfortunately, its nature permits little to be said. If its existence can be recognised the malady is generally advanced, and its observed rate of progress is the only ground on which a forecast can be based. When the central functions of the cord are considerably impaired, and the symptoms are steadily increasing, it is rare for life to be prolonged for more than one or two years, and the subacute onset of considerable paralysis may herald a course that leads to death in a few months. On the other hand, a stationary condition may last for many years. Treatment can do nothing for the morbid state, nor is it likely that the progress of spinal surgery can afford the means of relief.* The severity of some of the individual symptoms may, however, be lessened by appropriate measures ; especially trophic changes may be diminished by care and early treatment, bedsores may be prevented, cystitis guarded against, and if any acute para- lysis occurs, the possibility of some recovery may suggest the main- tenance of the irritability of the muscles by electricity, which cannot be expected to influence the slower atroj^hy. Fain may need the customary sedatives ; but early pain, especially with the hypersesthesia that depends on the intensification of the nerve-impulses at the irritated part, may be much lessened by the administration of cocaine, used as in tabes. Sudden pain in the spine may indicate commencing haemorrhage, and should lead to the adoption of the posture and other measures appropriate to that grave aiSection. AkaIiQIO PANABirnrM; Moevan's Biseabb. By the term Morvan's Disease is generally known an affection that was called Panaritium Analgicum, or " Painless Whitlows," by the physician of Brittany, Morvan, who, in 1883, first described it.f Observations on it are stiU. few,:j: but, judging from two fatal cases, § it • In one case under my care the spinal canal was opened and the cavity drained, but without improvement. t 'Gaz. Hebd.,' 1883, Nos. 35—44. J The chief writings are those of Louazel, * La Maladie de Morvan, Paris, 1890; Jeffrey and Achard, 'Arch, de Med. exp./ 1890 j Charcot, 'Prog. Med.,' 1890, No8. 11 and 12 ; Hackel, ' Miinch. med. Wochenschr.,' 1889. § Gombault, quoted by Charcot; Jeffrey and Achard, 'Arch, de Med. exp.,' 1891. 646 SPINAL COED. appears to consist in a combination of a condition of syringomyelia, or of the associated gliomatosis, with a peripheral neuritis in the extre- mities. The symptoms make the constancy of the neuritis probable ; we must wait to learn how far the morbid state of the cord is constant, and whether the changes in the nerves take origin in developmental conditions. It is quite possible that they may share the condition of arrested development, entailing a liability to later morbid changes, especially in view of the analogous conditions observed in the case mentioned on p. 629.* At the same time it is possible that the symptoms of this affection may be due to local neuritis of varied nature, and we must be cautious in inferring from them that the pathological state is the same in origin in all cases. In some instances the malady has been apparently set up by an injury. The affection has been met with in both sexes, but more frequently in males, and has generally commenced during the first half of adult life, betweea twenty and forty. When local injury has preceded the symptoms it has sometimes been at a considerable interval (Hackel), and it has been unilateral whenthe latter have been bilateral, so that its relation to them is uncertain. The characteristic symptoms are in the upper extremities ; only in rare cases do the feet suffer at a late period. Neuralgic pains may occur first, but the definite symptoms consist of weakness and muscular wasting in the hands and forearms, loss of all forms of sensation, and especially a peculiar trophic change — whitlows on the fingers, with recurring deep ulcerations in various parts of the digits ; those near the extremity of the fingers may only heal with the loss of some of the terminal phalanges. The loss of sensibility involves all forms, and usually precedes the occurrence of the whitlows, so that these are painless, a peculiarity which constitutes the most salient feature of the disease, and suggested, in the first instance, its special character. Occasionally the trophic disturbance precedes the anaesthesia, and the whitlows and ulcers are then painful. The latter are deep, a;nd often resemble the perforating ulcers of tabes ; cracks in the skin accompany them, and the nails shrivel and split. Vaso-motor derangements, lividity and pallor, often precede and accompany the disturbance of nutrition. The progress of the affection is very slow, and extends over many years ; one hand is usually affected some time before the other. The electrical irritability of the nerves of the part has been found normal in the early stage, and slowly vanishing as the malady pro- gressed. Although the trophic changes are limited, as a rule, to the hands, and the muscular wasting does not extend above the forearms, the loss of sensation is occasionally more extensive, involving the whole arms, parts of the trunk, and even the face. An affection of * In a case recorded by Jolly (' Charite Ann.,' xvi, 1891) there was also a coa» genital anomaly of the fingers, a web of skin between the third and fourth fingen of each hand. SPINA BIFIDA. 647 tLe shoulder-joint has been observed.* The feet are occasionally, though rarely, the seat of anaesthetic ulceration ; the legs have also been found weak, with excessive knee-jerk and foot-clonus (Hackel). In the autopsy that was made by Grombault neuritis was found in both arms, and also a diffuse overgrowth of connective tissue in the posterior part of the grey matter of the cord and the posterior columns. This growth involved also the coats of the vessels, which were in places so thickened as to obliterate their cavity. Neuritis has also been invariably found in the extremities of the fingers when these have dropped off. The features of the malady are so peculiar that, if they are known, the nature of a case cannot well be mistaken. Anaesthetic leprosy presents the closest resemblance, but in this the peculiar ulcerations are absent, and pigmentary alterations occur in the skin ; while in Raynaud's disease there is not the peculiar loss of sensibility, nor an equal tendency to whitlows, and vaso-motor disturbance is a more conspicuous feature. In the peculiar malady known as "sclero- dactyla " (a form of scleroderma that affects the fingers and face) there is no loss of sensibility or tendency to destruction of the finger ends. Simple syringomyelia is distinguished by the common absence of the whitlows, by the subordination, in time and degree, of the trophic changes to the other symptoms, and by the common preserva- tion of tactile sensibility. But the distinction is probably not an absolute one. In Morvan's disease there is peripheral neuritis as well as syringomyelia, and to this is due its special features, and especially the early and intense trophic disturbance.f Spina Bifida. Spina Bifida, or split spine, depends on a defect in the closure of the vertebral arches, which usually leads to the protrusion of the membranes as a sac, forming an external tumour, into which the lower part of the spinal cord often extends, normal or variously altered in conformation, sometimes even reduced to a neural lining of part of the wall. Rarely there is no external prominence — a form known as " spina bifida occulta." J The condition is most common in the lumbar region of the spine ; sometimes is present at more than one place, very rarely in the whole length of the vertebral column. It is met with in about one child out of every thousand born (Chaussier). The • Morvan, ' Gaz. Hebd,,' 1887, No. 34. f The absence of any fundamental difference between this malady and syringo- myelia has been pointed out by Bernhardt (' Verb. Vereins inn. Med.,' Berlin, January 19tli, 1891) and Jolly (loc. cit.). But the additional element of neuritis must not be ignored. J The best accounts of spina bifida are in the " Report of the Committee of the Clinical Society" ('Transactions,' 1885), and Bland Sutton's "Lectures on EvoIutioB in Pathology" ('Lancet,' February 25th, 1888). 648 SPINAL CORD. disease is one of chiefly surgical interest, and therefore only an outline of the more important facts is here given. The spinal cord, whether normal or not, generally reaches lower than usual in the vertebral canal, as it does at the early period of development, when the morbid state is produced, — becoming adherent at its lower extremity and remaining so. In many cases the central canal of the cord is enlarged above, and the lower part of the cord may also be similarly distended. The precise condition presents many variations, which can be, in part at least, understood by what is known of the process of development, a subject that has been very ably discussed by Bland Sutton. The essential element in spina bifida, the defect in the vertebral arches, depends on a deficiency in that ingrowth of the mesoblast from each side which should enclose the embryonal spinal cord, and fonn bone, after the superficial epiblastic layers have united to form the epidermis. A similar ingrowth of mesoblast forms the corium, muscle, &c. This apparently takes place in excess in spina bifida occulta, and leads to a curious condition, usually present — an excessive growth of hair over and about the affected part, which is generally the lumbo-sacral region. On the other hand, in many cases in which there is a tumour, this superficial mesoblastic ingrowth seems to be deficient, as well as that for the vertebral arches, so that at the upper part of the tumour there is an area in which there is no proper skin, but a peculiar shiny membrane destitute of hair. It is probably this superficial mesoblastic deficiency that permits the protrusion, and formation of an external tumour. In spina bifida occulta the defect in the arches can be felt on palpation, either in the lumbar or sacral region, and the spinal cord extends lower than normal, as in the ordinary form. The latter, in which there is an external tumour, presents three chief varieties. Fig. 190. — Spina bifida: sections of a spinal cord, from a case the symptoms and history of which I was unnble to ascertain. In A, cervical region, tlie only abnor- mality is a large cruciform ceniral canal and an unusually thick grey commissure. This continues through the dorsal region, at tlie lowest part of whicli there is a great change. In B, the canal is larger, and the necks of the posterior horns (and posterior vesicular columns) are united by much commissural tissue; in this, many vertical fibres could be seen, and others running from before backwards in the middle line. In C, an extension of the canal backwards has taken place, and it is bounded by a sinuous niembriine; The outer part of the grey substance is atro- phied. In D, the cavity has extended into each posterior horn, almost up to the surface of the cord, in part by a breaking down of tissue, because the membi-ane limiting the enlarged canal remains undestroyed. In E, still at the junction of the dor-al and lumbar regions, the cavity has receded from the left horn. In P, the division of the cord has taken place, not in the direction of the cavity in the horn (which is filled up), but in the middle line, at or close to the median septum. In G, a wider separation of the posterior columns has taken place, and a cavity has formed on the right side, which extends into the horn, and almost cuts ofi" the posterior column. In H, the cord is spread out and formed part of the wall of the sac. The posterior nerve-roots (jp r) mark the position at which the posterior horn comes to the surface. The grey matter is in many parts atrophied and translucent, and, in H, contains many large vessels. The septal lobulation on the surface of the c^rd is greater than normal. SPINA BIFIDA. Fig. 190. 649 650 SPINAL CORD. according as the sac contains only the spinal membranes (meningocele), the spinal cord as weU as the membranes (meningomyelocele), or the latter distended by enlargement of the central cavity (syringo- myelocele). These are the chief classes; they do not, indeed, exhaust the rarer forms, but to take fidl cognizance of these would entail a very complex list of varieties.* Of the several forms, that without an external tumour has been least frequently met with, although it is probable that a knowledge of the significance of the growth of hair in the lumbar region would lead to the detection of this state in many cases in which it is now undiscovered. Putting this form aside, simple meningocele and syringomyelocele are both rare ; the common form is meningo- myelocele, in wliich the cord, altered or intact, extends within the sac. The Clinical Society's Committee found that this was the condition in 62 per cent, of the cases in which there was an external tumour. The lower part of the spinal cord is generally adherent to the posterior wall of the sac, where its traction often causes a depression on the surface, always at the membranous area, which, as already mentioned, is generally to be observed in the upper portion. The cord may again become free, and extend downwards in the cavity, or it may be flattened, expanded, and lost in the wall, of which its tissue really forms an inner layer. In this layer there is no distinction of grey and white substance. In either case the lower nerves arise in the wall, and pass, first in this, and then forwards, across the cavity, to their fora- mina of exit. The arachnoid always extends into the sac, and the fluid is that contained within the subarachnoid space; sometimes there is an external opening from which the fluid flows. As a rule, the central canal of the cord is not continuous with the sac ; and it may be closed, even in the condition of syringomyelocele, in which the canal is dilated. In other cases the canal opens into the cavity, sometimes by only a small aperture, even when the lower part of the cord expands into the wall, and the nerves course along the w;all in a layer continuous with the arachnoid and superficial to the membrane that represents the cord -tissue from which they arise. As stated, ordinary syringomyelia may exist in the upper part of the cord. The extension of the cord in the wall of the sac probably indicates a developmental defect similar to that of the bony canal ; in the lumbar region the primitive canal has failed to close, so that the cord is open posteriorly, and the two posterior columns may even be far apart, or the cord may even be applied, in the form of a thick or thin lamina, to the wall of the sac. An instructive although rare example of the involvement of the cord in the developmental effect is shown in Fig. 190, which illus- trates also the manner in which the latter may involve in some degree the whole cord. In the cervical region the grey commissure is unusually large, and the canal is cruciform, a shape which it presents * Several otlier varieties are euumerated by Lilnud Sutton (loc. eit.). SPINA BIFIDA. 651 at one period of development, and which is here persistent. This condition obtains throughout the dorsal region until, in the lower part, the tissue behind the commissure is so abundant as to unite the necks of the posterior horns Below this the canal enlarges into a condition of syringomyelia, surrounded by the abnormal tissue which, as we have seen, is commonly associated with such enlargement ; the canal is limited, moreover, by the sinuous membrane that is so often met with (see p. 633). The cavity extends also into the posterior horns, clearly by a process of disintegration, since in d the membrane lining the enlarged canal persists, and marks the limit of the canal and the extent of the simple disintegration. The progressive separation of the posterior columns is shown in f, g, and h. In the lowest part of the cord, the development of the posterior columns has been appa- rently hindered, as will be observed if q be compared with f. In the former there are also some fissures in the grey substance, formed apparently by disintegration. The grey substance of the cord is con- spicuously wasted in the lumbar region, thin and translucent. In rare cases there has been no proper development of the cord. It was represented by a mere nerve-like string in a child, who also had hydrocephalus, but lived five weeks. Another child of the same parents had a similar condition.* Symptoms. — If the cord is intact, symptoms may be absent. In the cases in which there is an external opening, and a constant escape of cerebro- spinal fluid, the child usually dies in a few weeks. In other cases the defective development of the lower part of the cord, or its distension in syringomyelocele, is manifested by an absence of function, amounting to complete paraplegia in severe cases, which also seldom live. Some cases, however, survive, with paralysis and wasting of the legs, and often absence of power over the sphincters. In slighter forms the paralysis and wasting have been partial, either existing from the first, or supervening at some later period, probably from the occurrence of damage to the nerve-roots or cord-tissue by in- creased tension, or by inflammation; of the latter abundant traces may be found after death, and various external influences may readily set it up. Some children, whose legs have appeared natural, have never been able to stand ; possibly the defect in the posterior columns has given rise to a sort of congenital tabes. Even in the slighter forms, including spina bifida occulta, paralysis and atrophy have come on after some years, and even after adult life has been reached. Indeed, in the unsuspected forms without a tumour, there may be special danger of injury to the unprotected structures, and damage to the nerve-roots. The muscular paralysis and atrophy have been usually below the knees, and the muscles least prone to suffer are the tibiales antici. Hence talipes varus tends to occur. These muscles may alone persist, probably from the higber position of origin of their nerves (Eemak). Another pecxdiarity of these cases is the tendency * S. Wolfe, ' Phil. Kep.,' June 2nd, 1888. 652 SPINAL COED. to perforating ulcer in tlie feet, wMcli lias several times necessitated amputation. Chronic changes in the tarsal and metatarsal bonea have also been met with, somevs^hat like those of tabetic arthro- pathy.* The ulcers suggest neuritis, vrhich was found in one case ; and, in this and others, the arteries have presented thickening of the muscular coat, even leading to their closure. These symptoms may be greater on, or confined to, one side, and on this the knee-jerk has been lessened.f These points of resemblance to tabes may also be due to the greater degree of exposure to damage of the posterior roots, as well as to neuritis, perhaps descending. The treatment of spina bifida is purely surgical. That of the con- sequences just described is the same as for similar states in other diseases. TEAUMATIO LESION'S OF THE SPINAL CORD. Injuries to the cord fall within the province of the surgeon, but some account of them is needed because the subjects often afterwards come under medical observation, and because the cases present every gradation to the maladies that have been described in the preceding pages. Causes. — In fractures and dislocations of the sjDine, the cord gene- rally suffers compression or laceration, as already described in the chapter on injuj-ies of the vertebral column. The cord may also be directly wounded by stabs and gunshot injuries, in which it may be divided completely or partially. Such injuries furnish a considerable proportion of the cases of unilateral lesion of the cord. In gunshot wounds the cord more often suffers from displaced fragments of bone than from the ball itseK. Par more common than direct injury is damage to the cord by con- cussion of the spine, either local or general. Gunshot wounds occa- sionally furnish examples of local concussion ; a bullet may strike the spinal column and lodge in its vicinity, with the effect of causing immediate paraplegia, as complete as if the cord were divided, and yet it may be found that the spinal column has not been injured, and the cord is merely softened at the spot. Other causes of concussion are the fall of heavy bodies on the back, such as a beam of timber or a * In one case Sutton found the compact tissue very scanty, and the bones filled with semi-fluid fat; a deep ulcer reached a carious spot. t Di'tails of cases by Fischer, v. Recklinghausen, Brunna, and others, are quoted by Bland Suttoa (loe. cit.). See also Delafosse, 'These de Paris,' 1874; Eemak, 'Berlin, kl. WochenschiiCt,' 1885, TKAUMATIO LESIONS. 653 sack of com, a blow on the back from some blnnt weapon, a fall upon the back, either on a flat surface or on some projecting object. Less frequently the cord suffers from a general concussion of the body, in which the spinal column is not specially involved. The cervical region is occasionally damaged in falls on the head. Eailway accidents are frequent causes of concussion of the spinal cord; the back may be struck with violence when the body is thrown from one side of the carriage to the other. Another common cause is a fall • from a horse upon the back, or a fall downstairs, in which the spinal column is bumped against the edges of the steps. A violent bending of the spine may also injure the cord directly, especially in the more mobile cervical portion, where the region of the fourth and fifth vertebrae is especially apt thus to suffer (Thorburn).* The jar of the spine caused by a jump from a height may even be effective. Occa- sionally effects very similar to those which are produced by a blow on the spine are caused by a sudden contraction of the spinal muscles in some violent effort, a " rick of the back," as it is popularly termed. It is possible that, in such cases, the primary damage is sometimes to the vertebral ligaments and articulations, and that the cord suffers secondarily. The symptoms may only come on a few hours after the injury in such cases, as if effused blood compressed the cord, or the tension upon it and slight damage set up a graver inflammation. Thus a soldier, in a drunken quarrel, was extended by four comrades, two pulling on his feet and two on his arms, while a fifth sat on his back. No immediate effect followed, but the next morning there was complete paralysis of both arms and legs, which very slowly passed away. PATHOiiOGT. — The anatomical lesions in cases in which the vertebral column is not injured vary much in different cases. Haemorrhage is often found, sometimes outside the dura mater, sometimes on the inner surface of the membrane, in the pia mater, in the substance of the cord itseK, very rarely into the central canal, f Occasionally the substance of the cord has been found lacerated when the vertebral column has not been injured. In many cases there is local softenino-, commonly yellow in tint, sometimes mingled with red, often involvino- the whole thickness of the cord, and occasionally extending, as central softening, through a considerable vertical extent. Under the micro- scope the usual products of inflammation are seen, sometimes with hsematoidin crystals. Such softening may occur rapidly in severe local concussion, and be found complete a few weeks, or even a few days, after the injury. J On the other hand, in some cases of complete • ' Brain,* January, 1887. t As in a case reported by Chucan and Wickham, • Prog. Med.,' 1887. Probably it is only when the canal is previously dilated that this occurs, as it may, without serious injury to the nerve-tissue. J Edmunds, ' Brain,' vol. vii, p. 103; Obersteiuer, *Wien. med. Jahrb.,* Bd. iii, 1879 J Lochner, ' Bayer. Aerztlich. lat.-Bl.,' 1857, No. 42; Fromiiller, ♦ Memorabilien,* 654 SPINAL CORD. paralysis, no lesion of the cord has been found, either with the nated eje or the microscope, a few days after the injury.* In other instances, in which the cord is examined some weeks ui months after the accident, the signs of chronic myelitis are found, in scattered foci or more diffuse tracts, in the white columns or grey substance. The nerve- fibres are wasted, and the connective-tissue elements are increased in quantity, and in the early stages there may be a leucocytal infiltration about the vessels, dilatation of the capillaries, and minute extravasa- tions, although none may have been visible to the naked eye. In the anterior cornua the motor nerve-cells may be damaged, sometimes swollen and vacuolated, or shrunken, and the anterior root-fibres may be degenerated. The grey matter is especially apt to suffer when the enlargements are injured; in the dorsal region the change may be confined to the white columns. Ill-defined cavities may exist in old cases, where the nerve-elements have perished. The usual ascending and descending degenerations may be found above and below the most damaged parts. Occasionally there are indications of meningitis, diffuse or disseminated, and sometimes confined to the dura mater. Symptoms. — The effects, immediate and remote, of injuries of the spinal cord extend over almost the whole range of symptoms of cord disease, and their variations in character and course are almost infinite. It is therefore neither practicable nor necessary to do more, in this place, than to describe their general characters. According to the difference in coiirse, we may divide them into three classes. (1) Those in which the injury causes immediate and severe paralysis, due to instant damage to the spinal cord, the consequence of its laceration, compression, or concussion. (2) Those in which there are at first either no symptoms or only trifling disturbance of function, but in which grave symptoms come on a few days or weeks after the injury. (3) Those in which there are no early symptoms, or only slight and transient disturbance, but at the end of one or several months symptoms gradually come on, often such as indicate disease of some definite system or structure of the cord, degenerative in nature. (1) The first class, in which the injury causes instant and considerable disturbance of function, includes the cases in which the cord is directly injured, and also some in which there is no visible sign of damage if the patient dies within a few days. In the former class there is often a manifest lesion of the spine, and the cases are, at least at first, purely surgical in their practical relations. In the latter the mechanical influence has apparently abolished the function of the nerve-elements. If such patients live longer, either quick recovery 1870, No. 12. In the last, described further on, softening was found tbirty*two hours after the injury. • Fischer, * Deut. Zeitschr. f. Chirurg.,* 1883, Bd. xix. TRAUMATIC LESIONS, 655 ensues, or local softening from disintegration of the fibres that are most damaged. It is an interesting fact that concussion may thus derange function. The absolute integrity of structure on early micro- scopical examination shows that the result is not dxie to any minute vascular lesion. The effect has been compared by Eeynolds, not inaptly, to the demagnetisation of iron by a blow. Doubtless the influence is exerted on the molecular nutrition of the nerve-elements, and the possibility of recovery, or the subsequent structural dis- integration, depends upon the degree of nutritional damage.* The symptoms, in these cases of severe and immediate effect, are generally those of complete impairment of function. When the injury is direct and partial, such as a hemisection by an incised wound, or a partial bruise of the cord by a spicidum of bone being driven against it (as in the case mentioned at p. 236), the effect may be a partial (e. g. one-sided) derangement of function ; but in most other cases there is abolition of all the conducting functions at the level of the injury. There is complete paraplegia, motor and sensory, with loss of power over the sphincters. The symptoms are thus those of a total transverse lesion at the affected level (see p. 269). When the cervical region is injured, the arms are necessarily affected according to its seat. Such cases often illustrate very clearly the relation of arm-function to the cord.f The fibres for the sympathetic are often implicated, especially those for the iris, causing inequality of the pupils. Eeflex action below, abolished at first by shock, usually soon returns and becomes excessive, but remains absent if the lumbar enlargement is damaged, or is invaded by haemorrhage ; it may be again lost by the downward extension of secondary inflammation, which is equally effective when partial (in the posterior columns or grey matter) as when total, and is more difiicult to detect in the former case.J Loss of consciousness is occasionally produced by an injury which does not directly involve the head, as in the case mentioned on p. 656 ; vomiting is very common at the outset. The cases of direct injury often run a severe and rapid course ; and when the secondary inflam- mation spreads downwards, or the lower part of the cord is injured (as • These conclusions have been recently formulated more definitely, but without essential extension, by Schmaus, partly from experiments on rabbits ('Miincb. med. Wochensch.,' 1890). + See especially Thorburn, * Brain,' January, 1887. J This is the explanation of most cases of injury above fihe lumbar enlargement, with permanent loss of myotatic irritability, or of all reflex action, as in those described by Bowlby ('Lancet,' 1890, i, 1071). Such descending infla^iimation must not be contused with the descending degeneration in the pyramidal tracts which entails myotatic excess. The very rare exceptions mentioned on p. 264, in which Buch loss exists with no lesion to explain it, may be associated with the fact that myotatic irritability is sometimes lost in cases of cerebellar tumour. But the fact that superficial reflex action in the legs is never lost unless the lower part of the cord is diseased, is one of the most certain in patliology. Proof of such descending inflammation it given in the chapter on tumours (p. 617, note). 656 SPINAL CORD. is frequently the case), the tendency to trophic changes in the sMn, and to the occurrence of cystitis and pyelo-nephritis, is very great. (Edema of vaso-motor origin, and effusion into joints, may be pre- sent in the early stage. If the cord has been directly injured in its whole thickness, survival beyond a fortnight is rare. When it is damaged indirectly, with secondary softening — in what may be termed concussion myelitis — death occurs less rapidly, but many patients die a.t the end of four or six weeks, while in those who survive the first two months slow recovery often occurs. Even in such cases death sometimes occurs very quickly, but it is possible that there is then a laceration of the cord. A man, whose case has been recorded by Fromiiller, was struck on the back, at the level of the third dorsal, by a heavy beam, and had loss of motion and sensation up to the level of the nipples. The palsy of the muscles of respiration increased, and he died from asphyxia at the end of thirty-two hours. At the spot struck the cord was reduced to a pulp for 2^ cm., without any haemorrhage. The following case illustrates the occasional loss of consciousness when there is no evidence of any cerebral lesion. A heavy weight fell upon a man's back ; he was unconscious for two days, and at the end of that time the legs were completely paralysed, and continued so for three months, with retention of urine. Then improvement com- menced, in the left leg before the right, and in the latter some spasm developed. At the end of six months he could walk across the room on crutches. Improvement continued, but at the end of two years his condition became stationary, and when I saw him, six years after the accident, he could only walk haK a mile ; the right leg was still weak in all parts, and a foot-clonus was present in each leg, greater in the right than in the left. In cases in which the lowest part of the back receives the force of the blow, as when a severe fall ends in the sitting posture, and the sacral region is strack, the nerves of the cauda equina seem often to be specially damaged, and the posterior roots in greater degree than the anterior. The effect is to cause loss of sensibihty in the legs, varying in extent and seat according to the part injured, in some instances specially great about the anus, in others extending over almost the whole of the legs, in others again it is chiefly in the sciatic area ; all forms of sensation are usually involved. It is generally accompanied by some muscular paralysis and rapid atrophy, with the reaction of degeneration, especially in the muscles below the knees. Rarely no muscular paralysis exists; but there is loss of power over the sphincters in most cases. Reflex action is lost, and trophic changes are readily produced, both on the feet and over the sacrum. The sensory loss is often permanent, the injury to the nerve-roots being apparently too severe to permit recovery. As the case just mentioned shows, when the earlier effects of the injury are survived and improve- ment sets in, it is remarkable how long this may continue, and how TRAUMATIC LESIONS. 657 considerable a degree of recoyerj may be ultimately attained, it may be in the course of three or four years. (2) In cases of the second class initial symptoms are absent or slight. After the accident the sufferer may not imagine himself injured, and may be able to walk some distance without inconyenience. In other instances there is tingliag ia the legs, or in all the limbs, immediately after the concussion, sometimes with some weakness of the limbs, more often with a feeling of stiffness. In the course of a few days grayer symptoms come on, usually attended with spinal pain and tenderness, sometimes with some stiffness of the back, and often with pyrexia. Tingling in the limbs increases or deyelops, and is accom- panied by weakness, which often goes on to complete paralysis in the course of one to four weeks. The symptoms vary in their character and distribution, according to the position of the morbid process and its extent. In some cases, in which the dorsal region is most affected, the symptoms are those of simple paraplegia, usually with spasm, and sometimes with early contraction of the muscles. In other cases, in which the grey matter of the enlargements suffers, there is scattered muscular atrophy in the limbs, often with indications of the degene- ratiye reaction. Tremor in the limbs is conspicuous in some instances. A girdle-pain in the trunk, or sense of constriction in the limbs, is very common. The sphincters generally suffer, and the tendency to trophic changes is usually strong. The character and course of the symptoms is that of a subacute myelitis, and the meagre facts of morbid anatomy leave little doubt that this is the common lesion. Thus a lady was severely shaken in a railway collision. She seemed immediately after the accident to have suffered no injury, but in a few days paraplegia developed, and from its consequences she died six weeks after the accident. Throughout the dorsal region of the cord I found indications of subacute myelitis, chiefly in the white columns, varying in its extent in different regions, but most distinct in the pyramidal tracts.* Complete motor and sensory palsy, up to the level of the umbilicus, developed in the course of a week, after a fall downstairs in which the back struck successive steps. Yet the patient was able to walk immediately afterwards. The symptoms in these cases are sometimes unilateral. A man, driving Tinder a low archway, leaned back to save his head, and his spine was pressed suddenly against the sharp edge of the seat-back. He felt but little immediate effect, but in the course of two or three days complete motor palsy of the left leg came on, accompanied by hyperses- thesia, but without any loss of sensation either in that leg or in the other. Power slowly returned at the end of three months, and was in time perfect. In some cases of this kind the symptoms are due * In the face of such a case as this, it is superfluous to discuss the question raised by some writers whether or not the cord can sufEer concussion. Moreover it is certain that such an effect as was extreme in this case^ may and must often occur in slighter degree. VOL. I. 42 658 SPINAL CORD. not to direct damage to tlie cord, but to its compression by inflam- matory products outside it, tlie result of injury to the vertebral column. A clergyman was thrown from his horse, and there was immediately sufficient weakness of the legs to prevent him from walking; this subsequently increased, so that at the end of a fort- night the right leg was completely paralysed, while the left retained considerable power. There was a girdle-pain at the level of the umbilicus, and a bedsore formed, but he slowly improved, and regained the power of standing at the end of eight months. Such symptoms may come on weeks after the concussion, especially when the effects of this are so slight as to be disregarded, and the patient leads his usual life. When the damage involves the grey matter, the extent of the muscular wasting varies greatly. It seldom affects both arms and legs, but it is usually irregular in distribution, sometimes wide- spread, sometimes limited. Thus a young man fell from a horse and pitched on the head. He was stunned, and on recovering consciousness about two hours later felt " pins and needles " in both hands and pain in the back, followed by swelling of the neck and difficulty in moving it. The tingling ceased, but was followed by a sense of oppression about the shoulders, and persistent pain in the cervical region of the spme. When I saw him, two months later, there was some weakness of the right arm and wasting of the two outer interossei, and of that part of the long extensor which acts on the two outer fingers, with loss of faradic and preservation of voltaic irritability. Sensory symptoms are prominent in some cases of this class. Besides the pain in the spine, to be presently mentioned, pains are often felt in the legs, various in character ; still more frequent are spontaneous sensations of tingling, "pins and needles," and the feelings of defective sensibility described as "numbness." Various forms of hypersesthesia are also common, with or without such subjec- tive sensations. This may exist in any part, in the soles, feet, thighs, or not infrequently about the genitals. In the latter region, and about the anus, a sense of coldness is often complained of. In these regions there may be a distinct defect of sensibility, but this is slighter and less frequent than in the cases of the first class. Some degree of anaesthesia to touch may be associated with increased sensitiveness to stronger impressions. These sensory disorders may exist alone or be accompanied by motor weakness. Slight unsteadiness or definite inco-ordination is present in some cases, usually resembling that met with in ataxic paraplegia. In cases which survive the acute stage there is usually slow improve- ment, which is often ultimately very great. In many cases recovery is incomplete, but improvement goes on for years, as it does in the cases of considerable damage to the cord already mentioned ; the ultimate degree attained is commonly much greater than in cases of corresponding character and severity due to other causes than injury. TRAUMATTO LK SIGNS, 659 Some jjei'nictiient symptoms are left, chiefly wT'eii the initial deiixnge- ment of f anction has been severe, and has lasted for some time. (3) In the cases of the third class, chronic symptoms slowly follow an injury at an interval usually of some months, and the cases have the aspect less of a traumatic lesion of the cord than of a primary cord disease, the relation of which to the injury is rather an inference from the sequence, coupled with the absence of other causes, than an obtrusive fact, as in the cases of the first and second classes. The sym- ptoms are usually those of a definite system disease of the cord, less frequently those of a disseminated chronic myelitis of irregular distri- bution, still more rarely those of chronic focal myelitis. Primary spastic paraplegia, ataxic paraplegia, insular sclerosis, locomotor ataxy, and progressive muscular atrophy are the diseases which most frequently thus result. The fact that an injury is occasionally the cause of these maladies has been already mentioned in the account of their etiology, and the symptoms of such cases so far resemble those that are due to other causes that it is not necessary here to add anything to their his- tory as already given.* We must assume that the shock to the nerve- elements causes a slow perversion of nutrition, which is only mani- fested by disturbance of function when it has gradually attained a certain degree. Occasionally other causes co-operate, capable of producing degeneration. Previous syphilis, or neurotic inheritance, can sometimes be traced, and it is a reasonable assumption that the predisposition thus arising may assist in rendering the traumatic influence efficient, or in augmenting its effects. Intermediate cases connect this class with the last, cases in which we must assume, from indications of chronic inflammation, that definite injury was produced at one or more spots. An instance of this, and also of focal myelitis, was presented by a man with permanent spastic paraplegia and an intense girdle-pain at the level of the umbilicus. These symptoms commenced three months after a jump from a table, and shght unsteadiness, with pains in the legs, connected the jump and the paralysis. The several consequences of injury, which we have considered as oc- curring in separate form, are not only connected by intermediate cases, but are also sometimes distinctly combined. Thus an actual and immediate lesion of the cord may be associated with an early and severe increase in the symptoms from the development of subacute myelitis in other parts. The traumatic inflammation, at the spot damaged, often attains an intense degree, and runs a severe course, in consequence of the influence which may give rise to such inflammation, apart from a positive lesion ; and, in both cases, the damage to the cord may be perpetuated by a degenerative tendency It is very common, for instance, for an iajury to the cord, in those who have had * A case may, however, be mentioned in which typical tabes followed slow ly a fall on the back, recorded by Barbour (' Journ. of Nervous and Mental Discuses,* March, 1891, Case IV). 660 SPINAL COrtD. BypHlis, to cause acute symptoms wMcb. subside, but not perfectly ; and the residual disturbance of function may persist, and even increase in tlie course of years, in consequence of the influence of the previous sypbilis in rendering the nerve-elements prone to degenerate. Again^ it has been pointed out that the gouty diathesis is an unquestionable cause of myelitis, and often of the grave relapsing and spreading dis- seminated variety. A concussion of the cord, which causes only slight symptoms, may excite the occurrence of this form of myelitis in persons thus predisposed ; the symptoms of the later inflammation may come on months after the injury (the effects of which ha/e generally not quite passed away), and are sometimes excited by some over-exertion, or slight fresh concussion which would have had no effect on a healthy individual. I have known the symptoms of insular sclerosis, cerebral and spinal, to quickly follow traumatic paraplegia. One other symptom remains to be considered, which is common to all forms of traumatic lesion of the cord, and is often severe and per- sistent when other symptoms are slight — spinal pain. It may con- tinue for years after other symptoms have ceased, and probably depends on a neuralgic state of the nerves of the membranes or of those of the vertebral column ; often, probably, the pain depends on the nerves of the joints and ligaments of the spine. It is essentially a traumatic spinal neuralgia. The pain may be felt at one or more spots ; when severe, it often extends through a considerable length of the spine, and sometimes passes up to the occiput. It is occasionally referred to the sacrum, and may there have the character of a sense of weight or more vague discomfort. The pain is associated with tenderness of the spine, usually deep-seated, chiefly developed at the injured part, but sometimes present also at other spots. It may gradually assume the features of a true neuralgia, may occur in paroxysms, and be iaduced by mental and other influences which do not act directly on the spine, as well as by exertion, posture, and other agencies that may immediately influence the affected structures. This condition is often called " spinal irritation." The cause of traumatic lesions of the cord often acts also on the braia. A cerebral lesion may occur from the violence which affects the cord ; the cerebral symptoms then co-exist with those of the spinal lesion, and may mask the latter during the early stage. More common, however, is functional disturbance of the brain, the result, partly, perhaps, of the physical concussion, but chiefly of the mental shock which a serious accident necessarily causes. The resulting condition is favorable to the development and persistence of subjective sensory symptoms. Attention, maintaiaed by concern, has a powerful in- tensifying influence on all forms of nerve-pain, and certainly aids in keeping up the pain in the back, and even the tenderness which follows injuries to the spine. So marked is the influence of " nervous- ness" on the subjective symptoms, that it has been even maintained that in a large number of cases of concussion of the spine the THAUMATIO LESIONS. 6G1 symptoms are of hysterical origin.* Well-marked symptoms of hysteria are sometimes manifested by these patients. But, on the other hand, it is necessary to avoid the danger of over-estimating the effect of mental influence, and of regarding, as entirely due to this, symptoms which are real, and are merely intensified by attention. The danger is especially great in cases of railway injuries, concerning which an unbiassed judgment is not easy to secure, and in which, when objective symptoms are absent, it is easy to minimise suffering, and. attribute too much to the mental condition. The sinister influence of litigation on the intellect may be traced very widely.f I believe that it is rare for symptoms to be purely mental. It is often asserted by those employed for railway companies that subjective symptoms quickly subside when the sufferer's " claims " are settled, but it should be remembered that mental anxiety is a potent cause of diseases of the nervous system, and must be strongly opposed to recovery from genuine disorders. The occurrence of improvement when suspense is at an end is thus no proof in itself of the nature of the case, and its significance has been unquestionably over-estimated ; moreover, in a great many individuals whom I have had an opportunity of observing long after they had received their "damages" (as the expression curiously runs) this subsidence had not occurred, and even the " sove- reign balm " of substantial compensation has appeared to do very Httie for the relief of the sufferer. These opinions have been formed from a study of cases other than those that involve litigation, in which no elements existed to bias the judgment, and from a comparison of these with many " railway" cases observed apart from forensic proceedings. Those who desire to learn what can be said on the subject of " railway spines," as they have come to be termed, when viewed from the opposite sides, will find abundant material for consideration in the writings of Erichsen (' On Concussion of the Spine,' London, 1875) and Clevenger (' Spinal Concussion, or Erichsen's Disease,' Philadelphia, 1889) on the one side, and of Page (' Injuries of the Spine and Spinal Cord,' London, 2nd ed., 1885) on the other. Scattered papers by J. J. Putnam, Walton, Spitzka, Buzzard, and others, more or less instructive, will be found epitomised in Clevenger's work, where indeed is collected the pith of almost all that has been written on the subject. Diagnosis. — The chief points in the diagnosis of traumatic lesions of the cord have been already incidentally considered. Immediate symptoms may be due to laceration, haemorrhage, or to simple con- cussion, and the diagnosis between these is not always possible at first. If there are immediate symptoms of a partial lesion, these • J. J. Putnam, ' Boston Med. and Surgical Journal/ 1883, Sept. 6th. t Not many years ago it was customary for the " experts" who gMve evidence on behalf of railway companies to deny that the spinal cord could he injured if the legs were unwasted. Although the opinion dare not now be expressed, its significance is not without analogies at the present day. 632 SPINAL COED. indicate direct injur f, wliile tlie rapid snlDsidence of tlie disturbance of function render? simple concussion probable, and excludes any considerable direct injury. The later development of paralysis in- dicates myelitis, w Jess tbere is evidence of considerable irritation of tbe nerve-roots at a ''ertain level, vrliicli suggests inflammation outside the cord, and perhar s even outside the dnra mater. The greatest diagnostic difficulty is p.esented by the cases just mentioned, in which the sjTnptoms ar; subjective, and anxious attention has been long given to the local ''Jiscomfort. The chief elements in the diagnosis of these cases have ^/een, however, already indicated. It is important to search for, and tr give due weight to, any symptoms beyond the simple spinal pain. SI -ght " tingling " or " creeping " sensations may be of cerebral and " fu'ictional" origin, but apersistent sensation of " pins and needles" rarely 's of that nature. A definite sense of constriction is also stronjT.y suggestive of organic disease, and so is a well-marked differ' 3nce in the power of the muscles on the two sides. The latter is of V^st significance if the excess is slight, general, and on the riq^it side — of much greater significance if the diminution is partial, p^id. affects only certain groups of muscles, such as the flexors of the 'jip and knee, or the peronei. Any impainnent of power over the bladder or rectum is of great diagnostic importance ; loss of sexual power, on the other hand, is of little value, since this function is readily depressed by mental anxiety and preoccupation. A slight change in reflex action is most significant when it is partial. A foot- clonus or rectus-clonus is strong presumptive evidence of organic mischief. A slight excess of the knee-jerk is of little value ; although it probably always indicates some changes in the nutrition of the spinal cord, it does not indicate structural disease. In all cases it should be remembered that the absence of any common symptom is of far slighter significance, as evidence of integrity of the cord, than is the presence of that symptom as evidence of disease. It may seem superfluous to insist on a consideration so elementary, but it is still possible, as experience jDroves, for a medical witness to assert in a cou.rt of law that a claimant's spinal cord cannot have been injured because some symptom is absent, the presence of which would be important. Peognosis. — Immediately after an accident a cautious prognosis should be given, even if the symptoms are slight, on account of the possibility that grave disturbance may develop in the course of a few days. In developed cases the prognosis must in general be guided by the same considerations as those which determine our estimation of the probable course of symptoms of similar character and severity due to spontaneous myelitis. To this there are, however, two general exceptions. First, the danger of death, if any exists, is greater in traumatic cases than in others, as long as the symptoms are increasing. Secondly, if there is no danger to life, or such danger has passed, the prospect of improvement is distinctly greater than in a case of similar TEAUMATIO LESIONS. 6G3 features "but of non-traumatic origin. If the symptoms are sliglit or moderate in degree approximate recovery may be anticipated, although Blight symptoms often endure for a very long time. Indeed, in many cases recovery, although approximate, is not perfect. The patient is never quite as strong, never becomes quite as capable of exertion, as before the injury. A cautious prognosis should also be given whenever there is the late and gradual onset or increase of symptoms that suggests a degenerative process. Such degeneration presents far less tendency to arrest or subsidence than do the earlier lesions. As a rule the sooner symptoms occur the better is the prospect of ultimate improvement or recovery, provided they are not so severe as to be incompatible with life. Treatment. — The early treatment of these cases, and much of the later treatment of those in which the spinal column is injured, is purely surgical. The points of medical character alone need special mention, and many of these have been anticipated in the preceding pages. In all cases in which spinal symptoms are present im- mediately after an injury, however slight those symptoms may be, absolute rest should be insisted on for some days or weeks, according to the severity of the early symptoms. This is necessary on account of the secondary inflammation, which, as we have seen, so often occurs. The treatment of developed symptoms must be conducted on the same general principles as in cases of myelitis; the details need not be here repeated. If there is muscular wasting, it is important that the nutrition of the muscles should be maintained by electrical stimula- tion, since a very considerable amount of ultimate recovery may be anticipated, and it is important to keep the muscular tissue as far as possible in a condition to respond to the nerve-power when this returns. If there is reason to believe that there is inflammation of the membranes, or inflammatory effusion outside the cord, com- pressing it, mercury may be given, but this condition is probably much more rare than might be anticipated. The infliience of mercury on inflammation of the substance of the cord is doubtful. The chief element in treatment is patiently to permit time to do its work, and the tissues to slowly regain such integrity of structure and function as is possible; meanwhile preserving the patient from all influences likely to interfere with the process or to set up other mischief, such as cystitis or bedsores, which would entail fresh danger. There is, however, one therapeutic measure that is of unquestionable value in the treatment of the later stages, especially of the cases in which the recurring symptoms suggest a relapsing myelitis as the sequel of injury ; and that is the repeated application of a mild "actual cautery" on each side of the spine opposite the affected region. Several applications should be made, with or without an anaesthetic. It is not desirable to lessen the pain by cocaine, because this is likely to interfere with the influence of the proceeding, the beneficial character 664 SPINAL jCORD. of whicli is -andoubted.* The degenerative sequelse of injuries to tlie cord need tlie same treatment as the similar degenerations that occur apart from traumatic influences. Whenever there is evidence of dis- placement of the bones, or reason to suspect that the cord is compressed by fractured fragments, or even by products of secondary inflammation outside it, the propriety of trephining the spine needs to be considered. The problem is chiefly surgical, but the fact that it will probably not be necessary to open the dura mater increases the desirability of giving the patient this chance of relief. If needed, the sooner the measure is adopted, when improvement has ceased, the better. The treatment of the neuralgic condition of spinal pain and tender- ness, which so often succeeds injury, is frequently difficult. Counter- irritation is often useful, either by the actual cautery, blisters, iodine, or repeated sinapisms. Of sedatives, Indian hemp is most effective, next to morphia, which should be used as seldom as possible. Hypo- dermic injections of cocaine may be tried. When all active mischief is over, and the pain has become purely neuralgic, it is often neces- sary to encourage the patient to neglect it in some degree, and to exert himself in spite of it, while avoiding whatever increases it in considerable degree and for a considerable time. At the same time extreme care should be observed by all persons who possess the constitutional states above mentioned, predisposing them to myelitis, &c. This is especially necessary when any symptoms persist, and often difficult to secure, except by uncompromising insistence, in those who have been accustomed to a life of active exertion. FUNCTIONAL AND NUTRITIONAL DISEASES. Functional Diseases. Very little is known, though much is heard, of functional diseases of the spinal cord. It is, indeed, open to doubt whether there are any morbid states which can accurately be thus designated; as was pointed out in the Introduction, most morbid states thus described are either due to disturbance of cerebral functions, or are the result of changes in the nutrition of the elements of the cord. The deranged function may be an expression of altered nutrition, as it is of altered structure, but such cases can only be termed " functional " by a loose misuse of words. We have an example of the transference of our conceptions of functional derangements from the brain to the cord, in the fact that hysterical paraplegia is often regarded as a functional affection of the cord because the symptoms have the same distribution as those of organic diseases of the cord ; but a little consideration • For first directing my attention to the fact, and the evidence supporting it in these cases, I am indebted to Dr. John Anderson. FUNCTIONAL DISEASES. 665 will stow that, in a case of purely liysterical paraplegia, the morbid functional condition is cerebral ; the brain-centres which act on the legs are at fault, but the condition of the functions of the cord itself may be absolutely normal. The spinal motor centres are in a state of inactivity because the related cerebral centres are inactive, but this is no more a diseased condition of the cord than is its corresponding functional state during physiological rest. Hysterical paraplegia will be described, with other palsies of like origin, in the chapter on hysteria — a malady for which the term " functional " is often employed in various ways, as a convenient euphemism. At the same time, it must be remembered that there is no sharp line of demarcation between functional derangement and nutritional changes. As already mentioned, no functional state can exist without leaving behind it some corresponding change in the finer molecular nutrition of the structures ; and if functional derangemeni of lower structures results from that of higher cerebral centres, and is maintained for long, the change in nutrition that results may be considerable, and may be so definite as to persist even after its cause has ceased to act. Moreover the general enfeeblement of defective nutrition of the nerve-elements is a potent cause of this functional disturbance, and at once facilitates and augments such effects. The process may be observed in many cases not only of hysteria, but also of other derangements of the cerebral functions, and it is seen also in lower centres as an effect of pain. Isolated disturbance of functional centres in the cord does, however, sometimes occur. It is seen in the conditions of inhibition which are designated "reflex paralysis." Such palsies were once thought to be common and persistent, but it has been proved that many, and it is probable that all, cases of considerable and prolonged palsy, formerly thought to be of reflex origin, are due to organic disease, either primary in the cord or secondary to an ascending inflammation of nerves. But transient paralysis sometimes occurs, which cannot be otherwise explained than as an inhibition of a spinal centre, due to peripheral irritation. Such, for instance, is the curious inability to pass urine which sometimes follows an operation on the anus, — the division of a fistula, for instance, or the removal of haemorrhoids. The inability may continue absolute for several days. Transient weakness of one ai*m is said sometimes to follow an operation for empyema (Lepine), but the fact that the weakness may be attended by choreoid movements in both arm and leg of one side (Weil) makes it probable that the influence is exerted on a cerebral rather than on a spinal centre.* Considerable paraplegia was thought to be sometimes a reflex effect of disease of the bladder, or of a calculus or other organic disease in the kidney, but it is probable that such cases are always of organic nature. Ascending neuritis, reaching the cord, * Paralysis and wasting of serrati magni and infra-spinati muscles have, how- ever, followed double empyema (Cayley, 'Clin. See. Trans.,' 1898, vol. xxxi). 666 SPINAL COHD. has also been proved to be tlie cause of lasting symptoms in many «ases supposed to be of reflex origin. In one important class of cases in wMcli functional disturbance of the cord is purely secondary to a morbid state of the brain, organic or not, as has been already men- tioned, the expression in the limbs of all deranged functions of the brain is through the spinal cord ; but such disturbance of the cord is purely secondary, and ceases when the cerebral centres resume their normal state ; or, if it is continued longer, this is merely for a brief space of time, until the disturbed structures can regain their normal state. Thus, iii idiopathic epilepsy, the convulsion is produced through the agency of the spinal structures, and their over-action may leave them so exhausted that the reflex functions are for a short time abolished. But such conditions cannot be regarded as coming into the category of functional disease of the cord. The nearest approach to such disease is presented by certain forms of spasmodic disorder, such as transient fixed spasm, catalepsy, and certain forms of tonic spasm, which depend proximately on spinal centres ; and by some varieties of neuralgic and other painful affec- tions or dysaesthesise, in which the sensory elements of the cord are deranged in action. But we can seldom feel sure that the symptoms in the former class are dependent on a primary derangement of the cord ; more often they are clearly secondary to disturbance of cerebral centres, which may indeed co-exist, and the cases are better described among the general functional affections of the nervous system ; while those of the second class have features and alliances which make it more convenient to describe them among the forms of neuralgia. In another series of cases, derangement of the motor functions of the spinal cord is secondary to pain, generally that which has such a seat that it is increased by movement ; sometimes pain that is not related to movement, but is so intense as to act, by mere severity, on related structures. It may be in the spine itself, in the trunk, or in the limbs. Over-action of the motor centres and spasm may be the result, or the centres may be inhibited, causing a pseudo-paralysis, which may be real, but often blends with a voluntary indisposition to move the parts, lest pain be produced. Spasm is generally brief, and the reflex result of some sudden pain, as is often seen in the case of the " lightning pains " of tabes. When more prolonged contracture resixlts, as in cases m which hysterical contractTire follows some painful affection of a limb, the co-ox3eration of cerebral centres cannot be excluded. The inhibitory influence is strikingly seen in the immobility of one half of the thorax in pleurodynia ; and in brachial neuritis the effect may render it impossible to say whether or not there is real motor weakness. Some forms of spasm may perhaps be due to primary disorder of the spinal centres, such as the peculiar cramp in the hands, coming on during sleep, that is described in Vol. II as " nocturnal tetany," and the startings of the Hmbs on going to sleep ; but, for the most part, these spasmodic a,ffections are either FUiNCTlONAL DISEASES. 667 eecondary to morbid states of tlie cerebral motor centres, or form part of diseases of wider range in connection with whicb they are described. Other cases which may be regarded as functional are those in which symptoms, commonly subjective in character, result from some morbid blood-state. The conditions which most frequently have this effect are gout and diabetes. Occasionally there is defi- nite failure of power, lasting for a few days or weeks, without objective symptoms, and passing away. But the most common symptoms from this cause are sensory and subjective, — feehngs of tingling and formication in the legs, dull aching, and sometimes actual pain ; this is usually transient, but occasionally continues for some days or weeks, various in position, but in gouty cases often felt in the heels. Such symptoms due to morbid blood-states occur chiefly during the second half of life. Those of gouty origin, like other symptoms of the same class, are especially common in persons wha inherit a tendency to gout, but have not suffered from attacks of definite arthritis. In the diagnosis of functional disorders the first element is the ex- clasion of any sign of positive disease, and the second is the discovery of some morbid state capable of giving rise to the functional derange- ment, or of associated symptoms unequivocally functional in character. The first of these is that of primary and paramount importance, which, ahke in practice and reasoning, should precede the others. The various points involved in the diagnosis of hysterical affections are described in the chapter on that disease in Vol. II ; one only need be mentioned here — ^the importance which attaches to the state of myotatic irritability in the legs, and the great difficulty in ascertaining- it presented by many of these cases. Permanent excess shows that there is more than functional derangement; although it does not exclude the latter, it indicates changes in nutrition, and will be re- turned to presently. The cases in which the knee-jerk is apparently- absent present a special difficulty. It is never really absent in func- tional disorder (except when the centres are exhausted by violent convulsion), any more than it is in health. Failure to obtain it is due to the inabiHty of the patient to relax the muscles, which may render attempt after attempt futile, tmtil, in some fortunate moment, relaxation is secured and a characteristic jerk is obtained. The expedients that facilitate the attempt have been already mentioned (p. 21), and the subject has been sufficiently discussed in the account of the diagnosis of tabes. The treatment of functional disorders is that of the morbid states to which they are due, or of which they form part, and does not need special description. That of the symptoms due to toxic influences is necessarily the removal of the condition which causes them, but they may be to some extent relieved by sedatives, of which bromide of potassium, cocaine, Indian hemp, cimicifuga, and small (7 or 10 gr.) doses of chloralamide are the most effective. €68 SPINAL CORD. NXJTEITIONAL DISEASES. Among the cases often classed as functional diseases of the spinal cord are some in which objective symptoms of deranged function, slight in degree but definite in character, persist for months, years, or for life. They commence chiefly in those in the early and middle period of adult life, and are more common in women than in men. Such symptoms are inability to walk more than a short distance without fatigue, impaired nutrition of the legs, slight increase of myotatic irritability, often associated with pain in the back, aching in the legs (sometimes amounting to actual pain), and various spontaneous sensa- tions of tingling, " pins and needles," formication, and the like. There is often aching in the legs at night, especially when the patient lies on the back, and hence probably due to passive accumulation of blood in the spinal vessels. Such symptoms occur especially in those of neTurotic disposition, who often present other signs of the nervous weakness that it is now fashionable to term " neurasthenia." In many cases, if the history of such symptoms is traced, they will be found to date from some definite exciting cause, from an attack of acute illness, such as typhoid fever or acute rheumatism, from pregnancy, a fall, over- exertion, and the like, or to have come on during a period of general or nerve weakness, anaemia, anxiety, &c. Enfeeblement of the nervous system often results, and the impaired nutrition of the cord may be only part of a similar general state. A slight increase in myotatic irritability is exceedingly common, enough to permit the knee-jerk to be obtained by tapping the depressed patella ; but there is rarely a distinct clonus, at most only two or three jerks, quickly ceasing. We cannot conceive that symptoms so persistent can depend on any mere functional derangement ; it is probable that they depend upon changes in the finer nutrition of the nerve-elements, too slight to be detected by the microscope, but causing a corresponding and persistent alteration of function. We have seen that the termination of the upper segment of the motor path is probably that structure of the cord which has least nutritional stability, and is therefore most susceptible of nutritional derangement. Its degeneration is the apparent cause of persistent excess of myotatic irritability, and hence we can understand the frequency with which there is such an excess in these cases. There are probably gradations between such conditions and actual striictural disease in which minute examination reveals visible alteration; and there are certainly gradations between the symptoms above described, and those in which the derangement of function is so considerable and special that the case must be regarded as one in which actual disease exists, of one or other of the types described in the preceding pages. We have already had occasion to consider these nutritional changes as probably underlying the con- dition of arthritic muscular atrophy, and we have seen that the altera- NUTKITIUNAL DISEASES. 669 tions in spinal nutrition in tliat disease are apparently tie result of the impressions on tlie periplieral nerres. In women such a con- dition is often associated with uterine or ovarian pain, and with sacral pain apparently of uterine origin. It is possible that the condition we have been considering is sometimes secondary to such uterine pain, which acts in a manner somewhat analogous to that in which joint inflammation acts, and that this is the explanation of many of the cases in which a reflex disturbance of the functions of the cord has been supposed to be of uterine origin. The condition is also often associated with spinal pain and tenderness, which may have a similar influence. In the diagnosis of these nutritional affections of the spinal cord it is important to remember that they may be closely simulated by analogous changes in the peripheral nerves, constituting the slighter degrees and forms of polyneuritis. The chief points in the distinction have been described in the account of that disease. It is in the parenchymatous forms, and especially in the sensory varieties, that the danger of confusion is apt to arise. Symmetry in the distribution of the subjective sensations, or positive anaesthesia, and their localisation in the extremities, are the most important features of neuritic change. Connected with this distinction is another, of not less importance. Nutritional changes, equally with the simpler functional derangement, may be the result and expression of the action of some toxic blood- state, and aU that has been said ia connection with mere alteration in function applies also to the class now under consideration. Toxic influences cannot, indeed, act for long without leading to changes in nutrition, which may speedily attain a degree that amounts to visible structural disease. A search for such an agency should never be neglected in any case in which the symptoms have not followed an adequate cause, and do not form part of a general state of the same nature. But it must be remembered that the peripheral nerves are, as a rule, more susceptible to toxic influences than is the spinal cord, and this fact gives additional weight to any indications that it is from these that the symptoms proceed. Lastly, symptoms suggestive of mere changes in the finer nutrition of the nerve- elements are fre- quently the earliest indications of organic disease of one or another of the types already described, and in aU recent and progressive cases their general character and aspect must be carefully considered, and compared with the known features of the various organic diseases. The cases with such slight but persistent symptoms as have been just described vary much in their features, and may present all sorts of slight symptoms, in the utmost diversity of degree and combina- tion. To consider them in detail would be to describe an indefinite series of individual cases, no two 'of which are identical. The precise degree and manner in which the nerve-elements suffer may, it is evident, be almost infinitely various. Their corresponding manifesta- <370 SPINAL COED, tions present features, combiaations, and gradations tliat entirely baffle an attempt to designate tliem, or even to perceive definite types about wliicli they can be grouped. Tliese are some of the cases of disease "nliich exemplify the failure of types in practical work, the error involved in the attempt to give names, and the paramount importance, in the process of diagnosis, of considering what morbid condition the symptoms indicate, and of dealing with each case as a new problem, sui generis, whether or not it is ultimately found to be one of a familiar series. This method, moreover, conducts the practitioner at once to the morbid processes that need treatment, and should determine the character of his efforts to alter that which is at fault. It is unfortunately not common for the indications of nutritional disturbance of the cord, when they have been long established, to pass away altogether, although some degree of improvement can often be secui'ed; and in many cases, especially in those of brief duration, approximate restoration to a normal state may take place. The treatment necessarily varies according to the precise con- dition that exists, and the causes on which it depends. The removal of these as far as possible, and of any influence likely to depress the nervous system, must be the first consideration. It should be remem- bered that no part of the nervous system is unaffected by mental depression, and that impairment of the general health may render im- possible recovery from local disease. From these general principles the details of the treatment of individual cases, too vaiious to be here described, may readily be deduced. Therapeutic measures that are thus reasoned out and determined on by the indications of the special case are far more likely to be successful than those that are simply taken from a description of treatment. The only points that need special mention are, first, the importance of securing mental tranquillity by producing the conviction, when possible, that no grave disease exists or is impending, and with it the disregard of those slighter sensations of discomfort that become more aggressive and disabliag the more they are noticed. At the same time it is important that the patient should avoid aU over-exertion, all risk of falls or chills, and should be espe- cially careful in regard to sexual intercourse, which often has a pecToliar effect in augmentiag the symptoms ; and in the unmarried, perfect continence should be enjoined. Often, indeed, in the case of men, the mental preoccupation causes an apparent failure of sexual desire, which itself is a source of concern — generally groundless. Reassurance on this poiat frequently helps to secure the desii-ed mental state. Equally important is it to disabuse the sufferer's mind of the idea that seminal loss is weakening — an error widely prevalent ; the truth being that any depressiug influence comes only from the associated nervous action. But it is important to lessen undue frequency of nocturnal emissions, and for this nothing is so effective as Milton's remedy, large doses of the APPENDIX, 671 tinct. ferri percUor. (^\^s.x or xxx) tliree times a day, couiiled witt the avoidance of lying on the back. The relief of disabling pain, by the measTires described in the chapter on neuralgia, and by the treatment of any local morbid state, is indispensable. Eest from -work, the improvement of the general health, and the administration of nervine tonics, such as arsenic, phosphorus, quinine, strychnia, and the like, are the chief other points in treatment. A course of massage, or of gentle faradisation of the muscles, is also often useful. APPENDIX.* THE MUSCLE-SPINDLE. In 1862 Kolliker first described the muscle- spindle, and in the following year Kuhne added considerably to the description given by Holliker. Both these investigators considered that the muscle- spindle was a stage in the development of muscle and nerve, and although in the following years a considerable number of investigators on the Bubject published their researches, it was not till 1888 that Kerschner argued the sensory nature of the muscle- spindle. In 1893 Euffini described an annulo-spiral nerve termination within the spindle, but it remained for Sherrington in 1894 to prove by experiment that the nerve supplying the spindle passed up in the posterior root and definitely to settle the sensory nature of the muscle-spindle. Distribution. — Muscle- spindles have been found in nearly all skeletal muscles of the body, excepting the eye muscles and the diaphragm. They are abundant in the small muscles of the hand and in the arm muscles, and are more numerous in the belly of the muscle than near the tendon. In relation to this statement it is well to recognise that the musculo-tendon organs are foimd to be numerous in the region of the tendon. The muscle-spindle is present at all ages from the fourth month of fcetal life onwards. Size. — The size of the muscle-spindle varies considerably, not only in the same muscle but also with regard to the length of the muscle, and the age of the subject, being longer in the adult than in the child, * The following- account of the muscle-spindle has been kindly written by Dr. P. E. Batten, whose able and industrious researches on the subject render this ezprea* sion of Lia views most valuable. 672 APPENDIX, and in the larger muscles. Its average length is from 2 to 4 mm. (rg- to tV of ^^ inch), but it may measure as much as 12 mm. (j inch). The average breadth at the equatorial region is from '15 to •4 mm. No reliable estimate of the number of muscle-spindles within the muscles has yet been made, but seventy-nine have been found in ODe biceps. Varieties in the muscle- spindle exist. Thus, they are not always single, but may be compound, by the junction of two or more, so that the pole of one spindle enters into the equatorial region of another. Again, it is not uncommon to find spindles joined at their poles ; as many as three have been found in a row. Eufl^i distinguishes three classes of spindles according to the complexity of their nerve termina- tions. The muscle-spindle lies parallel to the muscle-fibre of the muscles in which it exists, and not unfrequently parallel to a nerve. It may lie wholly in muscle tissue, or partly in muscle tissue and partly in the connective tissue round the muscle bundles, or whoUy in the connec- tive tissue. Description. — The nomenclature adopted in the following description is that suggested by Sherrington, and the diagrams given will show the parts alluded to. The muscle-spindle is of the shape which its name implies. It is formed bj a capsule enclosing two or more fine Fia. 191. MliS.CLE SpwdIH EOUATORIAI. RecioH Pole oasnn^ (ANNULOrgPtRftU^ IkRitajtyrfrowij PCSTEENOINS f ^f«■ KOTOS.') mnscle-fibres. The capsule resembles the Henle sheath of a nerve, and at the equatorial region of the spindle consists of eight or more laminae, while at the poles it diminishes to a single lamina, and is lost on the flheath of the muscle-fibre. The muscle-fibres which enter the spindle are of smaller size than the normal fibres composing the muscle, the intra-fusal fibres measuring about '02 mm., while the extra-fusal fibres measure about •06 mm. As a rule, two or three of these fine fibres enter the pole of a spindle ; as they pass towards the equatorial region they undergo division, so that at this region of the spindle there may be eight or ten APPENDIX. 673 fine fibres, some of ttem measnriiig only '008 mm. At a certain point in the equatorial region some of the muscle-fibres lose their trans- verse striation and nuclei appear in the substance of the muscle- fibre. These nuclei gradually increase in number till they completely fill the fibre, then after a short distance they become less numerous, and the muscle-fibre again resumes its striation. At the equatorial region the muscle-fibres do not fill the whole spindle, but lie to one side. As they pass to the distal end of the spindle they become joiaed again and pass out of the spindle as two or three fibres. It will be seen from the above description that a transverse section of the spindle may at a given point in the equatorial region seem to contain no Pio. 192. — Normal spindle of child in transverse section. Magnified 260 diameters. 1. Section near the pole. The areas marked with veitical lines are muscle-fibres in transverse section. 2. Nerve entering into spindle. Many of the dark bodies in contact with the muscle-tibres are nerve-fibres. 3. Nearer the equatorial region the sheath has acquired considerable thickness. 4. At the equatorial region the muscle-fibres have undergone consider* able modification, and are no longer recognisable as such. 6. The spindle near the opposite pole ; the muscle-fibres have resumed their natnral appearance. 6. At the distal pole of the spindle. VOL. I. 43 674 APPENDIX. nmscle-fibres, tlie structures of such having been so profoundly modified (Fig. 192, 4). Nerve-supply. — The nerve-supply of the spindle is always large — as a rule at least two nerves pass to it, one at the equatorial region and another at the distal or proximal end. It is, however, by no means uncommon to find spindles with four or five nerves. The nerve passing to the equatorial region always contains a nerve-fibre of large size measuring about '008 mm. This nerve on entering the spindle loses first its Henle sheath, which fuses with the sheath of the spindle, and next, after entering its medullary sheath, it then divides into two and forms the annulo- spiral nerve termination of Euffini, winding round the muscle-fibres at the point where the nuclei are situated in the muscle-fibre. From the nerve that enters the equatorial region other fibres pass towards the poles of the spindle and lie between its muscle- fibres ; the mode of termination of these fibres is imcertain in man, but probably corresponds to the secondary ending described by Euffini. The nerves which enter the poles of the spindle are nearly always composed of fine nerve-fibres having a diameter of '004 mm. ; they likewise pass between the muscle-fibres of the spiadle and pass towards the equatorial region. The question whether the muscle-spindle contains a motor nerve termination is one that has not yet been determined, for the third form of nerve ending described by Euffini and named the " plate ending" is said by him not to be motor. Owing to the number of nei"ve-fibres within the spindle there is a plexiform arrangement of nerves between the muscle-fibres and the sheath of the spindle, but so far as can be ascertained they do not intercommunicate to form a true plexus. These nerves are myehnated. Blood-vessels. — The muscle-spindle is supplied by arteries and veins, which most frequently enter the spindle near its equatorial region. TJnd&i' certain pathological conditions the muscle-spindle, owing to its apparent immunity from change, stands out in striking contrast to the surroundiag muscle tissue. In all wasting diseases, and especially in phthisis, the muscle-spindle forms a very marked feature in sections of the muscle, but no change has been demonstrated in the structure of the spindle. It is for the same reason more striking in the muscles of a child than those of an adult. In infantile paralysis, although all the surrounding muscle tissue may have been atrophied or have undergone fatty degeneration, yet the muscle-spindle is normally preserved and supphed by a perfectly normal nerve. Similarly in progressive muscular atrophy exactly the same condi- tion can be demonstrated, although in these cases the atrophy of the surroundiag muscle may not be so extensive. In the myopathies the muscle- spindle forms a very striking appear- ance, as is shown by the description given of them in pubHshed cases of this disease. They remain, however, perfectly normal both with APPENDIX. 675 regard to their nerve-supply and the character of their muscle- fibres. In peripheral neuritie certain changes have been described within tli:^ mnscle-spindle both as regards the muscle- fibres and also as regards the nerves; in other cases, however, they have been shown to be perfectly normal. In tabes dorsalia, although the external form of the spindle and the nerves passing to it have been found to be normal, certain changes have been described in the intra-fusal muscle-fibres. The evidence, however, on this point is insufficient at the present time to justify us in regarding the changes described as constant in this disease. Beferencea. — Shkbbington, 'Journal of Physiology,' voL xvii, p. 237, 1895 1 Ru?7iNi, 'Joarnal of Physiology/ toL zziU* p, 190^ 1898} Bahbn, 'Biain,' toLzz,p.138,1897. INDEX. A Abdominal reflex, 20 Abductor minimi digiti, 62 — pollicis, 44, 52 Abscess of spinal cord, 377 Accessory hsematoinyelia, 488 Action, antergic, 10 — reflex, 19 — synergic, of muscles, 10 Acute anterior polio-myelitis, 396 — ascending paralysis, 371, 427 — atropbic paralysis, 396 — myelitis, 344 Adductor brevis, 47 — longus, 47 — magnus, 47 — poUicis, 52 Adductors of tbigh, 47» 232 ^sthesiometer, 14 Afferent tract crossed, 223 Albinism and pseudo-bypertropbio para- lysis, 569 Alcoholic ataxia, 168, 159 {see Pseudo- tabes) — meningitis, chronic, 824 — neuritis, 150 — pseud o-tabes, 159, 173, 175, 372, 481 Alcoholism in myelitis, 347, 380 Alimentary canal, nerve-centres for, 247 AUocbeiria, 14, 453 — in tabes, 453 Amyloid bodie>, ;U8, 527 Amyotrophic liiunil sclerosis, 581 {see Progressive muscular atrophy) Anemia of spinal cord, 839, 340, 513 Anaesthesia, 13 — dolorosa, 260, 393 Analgesia, 15 Analgic panai-itinm, 645 Anastomotic artery, 227 Anatomical diagnosis in cord disease, 253 Anatomy of spinal cord, 200 Aneurism, erosion of vertebrae by, 305 Angioglioma, 609 Angiosarcoma, 609 Angular curvature, 287, 290, 291 Ankle-clonus, 22 Annular myelitis, chronic, 882 — sclerosis, 382 Anode, 73 Antergic contraction, 10 Anterior central artery, 227 — column, 201 — cornua, anatomy of, 204 — crural nerve, diseases of, 115 — neuritis of, 134 — ground-fibres, 223 — lateral arteries, 227 — median arteries, 226 — — • fissure, 201 — polio-myelitis, 395 — pyramidal tracts, 207, 209 — radicular arteries, 227 — root-fibres, 207, 224 — spinal artery, 226 vein, 227 Antero-lateral column, 201 — tract, ascending, 201, 208, 222, 470 — — degeneration in tabes, 470 — — descending, 215, 223 Arachnitis, 809 Argyll Kobertson pupil, 455 Arm, combined palsies of nerves of, •— diseases of nerves of, 110 — motor points, 38, 39 — muscles, 84 Arteries of spinal cord, 226 — 228 Arthritic muscular atrophy, 559 Arthritis, vertebral, 307 Articulations of spine, diseases of, 807 Ascending neuritis, 82, 85 — paralysis, acute, 371, 427 Ataxic paraplegia, 503 — 511 678 INDEX. Ataxy, 258 — cerebellar hereditary, 524 — hereditary (Friedreich), 519 — in multiple neuritis, 153, 159 (see Pseudo-tabes) — in tabes, 449 — of movement, 10 Athetosis, double, 496 Atrophic spinal paralysis, acute, 396 — subacute and chronic, 424 Atrophy, atonic muscular, 540 — idiopathic muscular, 564 — muscular, from over-use, 563 family form of, with spinal lesion, 597 peroneal form, 593 — of auditory nerve, 457 — of optic nerve, 457, 503 — progressive muscular, 531 — pseudo-hypertrophic, 564, 567 Axis-cylinder, compound character of, 55, 62 — process, 65 Axites, 56 Axon, 55, 204 B Bedsores, changes in nerves near, 68, 83 Bending of spine, violent, 586, 591 Beri-beri, 186 Biceps cruris, 47 — muscle, 39 Bladder, centre for, 245 (see Sphincters) — condition of, in pseudo-hypertrophic paralysis, 575 — ulceration of, in myelitis, 362 Blood-supply of cord, 226 Bones in infantile palsy, 404i — in syringomyelia, 643 — nutrition of, 245 Brachial neuritis, 119 — plexus, diseases of, 98 Brachialis anticug musr>le, 83 Bronchial crises, 482 Brown-Sequard, experiments oa sensation, 234 Burdach's column, 200, 219 Caisson disease, 433 Calf muscles, centres for, 232 C^fUus, effects of, on nerves, 101 Quput cornu posterioris, 206, 225 Carcinoma of cord, 608 Caries of spine and tumour, 803 — — disease of cord in, 286 syphilitic, 305 Cauda equina, tumour of, 216, 610 — and syringomyelia, 636 Cautery, actual, in traumatic lesions, 664 Cavities in cord, 629 Cell-body, structure of, 59 Cells of anterior horn, 204 — unipolar, 57 Cellulif ugal dendrites, 58 CelluHpetal dendrites, 58 Central canal, 224 Cerebellar ataxy, hereditary, 524 — tract, direct or dorsal, 207, 209, 220 ventral, 208, 222 («e« An tero-lateral ascending) — tumour and tabes, 483 Cerebro-spinal motor segment, 213 Cervical enlargement, localisation in, 231 — muscles, centres for, 231 — vertebrae, fracture of, 283 Charcot's joint disease, 266, 459, 643, 652 Cheyne-Stokes breathing, 318 Chronic atrophic paralysis, 531 — meningitis, 322 — myelitis, 378 — polio-myelitis, 424 — spinal muscular atrophy, 5S1 Circulation in cord, 226 Circumflex nerve, disease of, 103 Clarke's column, 206, 221 •— — in tabes, 471 Clasp-knife rigidity, 265, 493 Classification of nervous diseases, 1, 8 Claw-like hand, 43, 109, 639 Clonus, foot, 11, 12, 22 — spurious, 501 Coarse disease, 1 Cold, exposure to, in cord disease, 277 Collaterals, 55 Column, antero-lateral ascending, 201, 208, 222, 470 — — descending, 215, 223 — of Burdach, 200, 219 — of Clarke, 206, 221 — of GoU, 200 — of Gowers, 201, 208, 222, 470 (««• Antero-lateral ascending) — of Tiirck, 210 — posterior, 215 INDEX. 679 Column, posterior vesicular, 206 — postero-external, 200, 219 — postero-median, 200, 207 Combination of symptoms in cord disease, 269 Comma-shaped degeneration, 216, 219 Commissural artery, 226 Commissures of cord, 201, 223, 224 Compression, effects of, on nerves, 80 — myelitis, 276 — of cord, 390 Concussion myelitis, 652 Conduction in cord, 228, 233 Congenital paramyotone, 605 — spastic paraplegia, 495 — tabes and spina bifida, 651 Congestion, 2 Contraction, fibrillary, 8, 257, 539 — idio-muscular, 8 — in pseudo-hypertrophic paralysis, 574 — myotatic, 26 Contracture, 12, 256 — after facial palsy, 77 Contra-lateral muscles, 84 Convulsions in cord disease, 269 Co-ordination of movement, 11, 242 Cord, 274 — abscess of, 377 — affection, symptoms of, 253 — anatomy, 199 •— blood-supply of, 226 — cavities and fissures in, 629 — degenerations of, 442 — diseases of, 199 — embolism of, 377 — functions, 228 ■^ grey substance of, 203 — in peripheral neuritis, 168, l76 — inflammation of, 343 — membranes of, 199 — softening of, 275, 276 — tumours of, 607 Cornu-commissural tract, 220 Corpora amylacea, 348, 527 Cramp, 17 Cremasteric reflex, 20, 232 Crises in tabes, 462 Crossed afferent tract, 223 — pyramidal tracts, 209 •— sensation, 272 Cross-legged progression, 496 Croreus muscle, 47 Crutch palsy, 105 Cuiieate nucleus, 219 Curvature, angular, 287, 290, 291 — of spine, lateral, 307 — in Friedreich's disease, 523 7— in idiopathic muscular atrophy, 688 — in infantile paralysis, 408 — in pseudo-hypertrophic paralysis, 575 — in progressive muscular atrophy, 538 — in syringomyelia, 642 — lateral, 307 Cutaneous reflexes, 20 — sensibility, representation of, in cord, 238 Cysticerci of cord, 609 Cysts in cord tumours, 614 D Deafness in tabes, 457 Decussation of sensory fibres in cord, 234^ 235 Deep reflexes, 19, 20, 238 Deformities from infantile palsy, 405 Degeneration, 4 — bilateral, in cord, 211 — comma-shaped,' of cord, 216, 219 — fatty, of muscle, 546 — granular, 546 — in cord, 217 — in myelitis, 355 — irritative character of, 68 — reaction of, in muscle, 31, 32 in sensory nerves, 405 — retrograde, 215 (foot-note) — secondary, of nerves, 65 — Wallerian, 65 Degenerations of cord, 274 ascending, 208, 215 descending, 208, 210 — vitreous, of muscle, 70, 546 Degenerative neuritis, 32 — reaction, 32 Deiter's cells, 201, 351 Delay of sensation in tabes, 452 Deltoid muscle and centre, 36, 231 Dendrite, 55 — celluli petal, 58 Dendron, 55 Descending antero-lateral tract, 216 — degenerations, 208, 210, 223 Deuteropathic progressive muscular atrophy, 532 630 INDEX. Development of cord, 629 Diabetes, sclerosis in, 513 Diagnosis, pathological, 274 Diaphragm, action of, 33 — centre for, 231 — inflammation of, 97 — paralysis of, 33, 99, 537 DilVuse niyelitis, 344 Diphtheria and cord disease, 278 Diphtheritic neuritis and tabes, 483 Diiect cerebellar tract, 207, 209, 220 — pyramidal tract, 207, 209 Disease, nature of, 278 — nutritional, 2, 664, 668 — organic, 2 — seat of indications of, 278 — structural, 2 Dislocation of spine, 281 Disseminated myelitis, 351, 353, 865, 370 — neuritis, 84 — sclerosis, 275 Diver's paralysis, 453 Dorsal reflex, 20 — vertebrae, fracture of, 286 Duchenne's disease, 445 Dura mater, haematoma of, 323, 327 tumours of, 308, 607 Dynamometer, 9 Dyssesthesia, 15 Dyslexia, 341 Dystropliies, muscular, 563 Dystrophy, muscular, 563 E Echinocoeci, 543 Elbow extensors, centre for, 231 — flexors, centre for, 231 Electrical irritability, 29 — 31 — — in functional disease, 32 — reaction, changes in, 75 in progressive muscular atrophy, 539 — treatment in infantile paralysis, 422 Elephantiasis neuromatodes, 93 Embolism of cord, 377 Embryonal tissue and syringomyelia, 629, 632 and tumours, 613, 634 in nerves in Friedreich's disease, 629 — — persistence of, biJy Emphysema, subcutaneous, in myelitiflt 362 Empyema, paralysis from, 665 Encephalomyelitis, disseminated, 344^ 365 Enchondroma of cord, 608 Endemic neuritis, 185 Epidemic meningitis, cerebro^spinal, 822 partial, 320 Epigastric reflex, 20 Erb's paralysis, 112, 407, 565 Erosion of spine by aneurism, 305 Essential paralysis of children, 895 (set Infantile paralysis) Excentric pain, 260 Excitation, 61 Exophthalmos in pseado • hypertrophie paralysis, 587 Exostoses, vertebral, 304 Exposure in cord disease, 277 Extensor quadriceps, 47 Extensors, nerve-centres for, 232 — of ankle, 50, 52 — of elbow, 231 — of fingers, 40, 232 — of foot, 51 — of knee, 47, 232 — of thumb, 42—44 — of toes, 50, 52 — of wrist, 40, 231 External meningitis, 309 — ophthalmoplegia, 457 — popliteal nerve, disease of, 117 Extra-dural tumours of cord, 607 Extra-meningeal hsemorrhage, 320 Eye symptoms in tabes, 457 Eyeballs, trophic changes in, 28 Pace in idiopathic muscular atrophy, 587 — in neuritis, 161 — in progressive muscular atrophy, 538 Facial nerves in leprous neuritis, 193 — type of muscular atrophy, 665, 587 False neuroma, 90 Paradism, 29. 75 — in infantile palsy, 422 Fasciculi of nerve-fibres, 63 Patty degeneration of muscle, 646 Fibres, grey, 63 — non-meduUated, 63 — regreneration of, in cord, 356 INDEX. 681 Pibrilbtion of muscle, 8, 257, 539 Fibrils, cellulif iigal, 58 — primitive, 55, 56, 62 Fibromata in nerves, 90 Fifth nerve, degeneration of, in tabes, 451, 453, 474 Fingers, extensors of, 40, 232 — flexors of, 41, 232 Fissures in cord, 629 Flat-foot, 50 Fiexibilitas cerea, 27 Flexors, nerve-centre for, 232 — of elbow, 231 — of fingers, 41, 232 — of foot, 52 — of knee, 232 — of wrist, 40, 232 — long, of fingers, 52 — short, of fingers, 52 — long, of thumb, 44 ■ — short, of tliunab, 44 of little toe, 52 Foot muscles, 48. 232 — — nerve- centres for, 232 — phenomenon, 22 Foot-clonus, 12, 22 — nerve-centres for, 232 Forearm, muscles moving the, 87 Fracture of spine, 282 Fractures, spontaneous, of bone, 459 Friedreich's disease, 519 Functional disease, 1, 276, 664 Functions, mutual relations of, 249 172 ^— tubercular, 147 — varieties of, 82, 144 — - vocal cords in, 156 Neuro-fibroraa, 93 Neuroglia, development of, 629 — structure of, 57, 201 Neurokeratin, 62, 202 Neuroma, 90 — amputation, 93, 95 — amyelinic, 90 — false, 90 — multiple, 92, 609 — myelinic, 90 »— of nerve-roots, 544 — plexiform, 91, 93, 94, 96 Neuromatodes elepbantiasii, 9S Neuromyositis, 134 Neuron, 55 — cerebro-spinal, 218 Neuron, spino-muscular, 213 Neuropathic disposition in cord disease, 277 Neuropilema, 54 Neurotabes, 175, 448 (see Pseudo*tabeg) Nodes of Ranvier, 62 Nuclei, internodal, 63 Nucleus cuneatus, 219 — function of, 59 — gracilis, 216, 219 — post-pyramidal, 219 Nutrition, changes in, 127, 277 — influence on, of cord, 244 Nutritional disease, 1 of cord, 2, 664, 668 Nutritive changes in muscles, 70 in skin, 28 Nystagmus in ataxic paraplegia, 506 — in Friedreich's disease, 521 — in multiple neuritis, 157 — in progressive muscular atrophy, 542 — in spastic paraplegia, 495 — in syringomyelia, 643 Obstetrical paralysis, 118 Obturator internus, 46 — nerve paralysis, 116 Ocular symptoms in tabes, 456 (Edema, vaso-motor, 618 Operation for tumour, 626 Ophthalmoplegia, 457 Opponens pollicis, 44 Optic atrophy, 457 — — in ataxic paraplegia, 506 — ^ in family spastic paralysis, 508 Optic neuritis in chlorosis, 341 — — in multiple neuritis, 163 — — in myelitis, 362 Organic disease of cord, 1 Organismal neuritis, 146 Organisms in beri-beri, 186 — in myelitis, 346, 347 Oval field of Flechsig, 218 Overflow incontinence, 246, 361 Over*nse, muscular atrophy from, 668 Pachymeningitis, 174, 309, 666 — and progressive mnscolar atrophy, 656 — cervical hypertrophic, 326, 623 — cervical, and syringomyelia, 644 INDEX. 687 Pachymeningitis, chronic, 322 — external, 309 — internal hremorrhagic, 309 Pain, conduction of, in cord, 236 — in cord diseases, 260, 393 tumours, 393, 615 — sensibility to, 15, 236 in syringomyelia, 641 Pains, excentric radiating, 260 Palmar fascia, contraction of, 41 Palsy, Erb's type of, 112, 565 — infantile, 396 Paradoxical muscular contraction, 27 Paraesthesia, 15 Paralysis and paresis, 9 — acute ascending, 371, 427 — agitans, tremor in, 12 — atrophic spinal, 395, 424 — essential, of children, 396 — from lessened pressure, 453 — infantile, 396 — — electricity in, 421 — — neuritis in, 400, 414 — of muscles, 33 — periodic, 598 — pseudo-hypertrophic, 564, 567 Paramyotone, ataxic, 606 — congenital, 605 Paraplegia, 253 — ataxic, 503 and meningitis, 331 — chlorotic, 341 — congenital spastic, 495 — dolorosa, 261, 301 — hereditary spastic, 503 — primary spastic, 489 — -^ — and ataxic, 499 — — ^ family form, 503 — — — infantile form, 496 — simple senile, 530 Parasitic tumours of cord, 608, 609 Parenchymatous inflammation, 4, 274 — myelitis, 366 — neuritis, 82, 84 Paresis, 9 Pathological diagnosis of cord disease, 274 Pathology and etiology of cord disease, 274 Pectineus muscle, 47 Pectoralis major, 37 Pellagra, 511 Pelvic outflow, 248 Perimeningitis, 309 Perineuritis, 82, 83 Perineurium, 63 Periodic paralysis, 598 Peripachymeningitis, 309 Peripheral arteries of cord, 227 — nerves in tabes, 473, 480 — neuritis, 138 {see Neuritis). Peroneal nerve, paralysis of, 117 — type of atrophy, 534, 593 — — combined with idiopathic, 597 Peroneus longus muscle, 50, 232 — brevis muscle, 52 Phrenic nerve, diseases of, 33, 96, 97 Phthisis and peripheral neuritis, 169 Plantar nerves, diseases of, 117 reflex, 20 Plexiform neuroma, 91, 93, 94, 96 Plexus, lumbar, 114, 116 — sacral, 114, 116 Polio-myelitis, 396 — chronic and subacute, 343, 386, 424 PolysBsthesia, 14, 453 Polymyositis, acute, 185 Polyneuritis, 82, 138, 173 — septicsemic, 146, 148 — tubercuhir, 147 Popliteal nerves, diseases of, 117 Popliteus muscle, 48 Post-pyramidal nucleus, 219 Posterior central artery, 227 — column, function of, 215 — cornual artery, 227 — ground fibres, 207 — intermediate septum, 200 — lateral arteries, 227 — medial artery, 227 — median column, 200 — — septum, 200 — nerve-roots in Tabes, 472 — pyramid of medulla, 219 — radicular artery, 227 — root fibres, 207, 225 zone, 200 — spinal vein, 227 — thoracic nerve, 101 — vesicular tract in tabes, 206, 471 Postero-external column, 200, 215, 219 Postero-mediau column, 200, 207, 215 Posture, adaptation to, 241 — loss of sense of, 18, 237, 259, 454 Pott's disease, 286 Power, measurement of, 9 688 INDEX. Pressure myelitis, 276, 853, 391 ■^ sense of, 14 Priapism, 263 Primary hsBmatomyelia, 437 ^ lateral sclerosis, 489 ^ — and general paralysis, 497 — — and hysteria, 501 — — — infantile, 495 — spastic paraplegia, 489 ^ — - — family form, 503 — — — infantile, 495 Primitive can-il of cord, 629 — fibrils, 55, 56, 62 — sheath, 62 Progressive muscular atrophy, 531 — _ and pachymeningitis, 556 _ — and syringomyelia, 556 — .» — and tabes, 466 Pronators, 40 — nerve centres for, 232 Protopathic progressive muscular atrophy, 632 Protoplasmic processes, 56 Pseudo-hypertrophic paralysis, 564, 667 __ ^ mode of rising in, 572 — — varieties of, 576 — tabes, 159, 173, 175, 372, 481 Psoas muscle, 46, 232 Ptosis in tabes, 456 Pulse in tabes, 462 Pupil in cord disease, 266 — in myelitis, 362 Pyramidal fibres, 207, 209, 210, 255 __ _ mode of ending in cord, 212 — tracts in progressive muscular atrophy, 550 Pyrexia in cord disease, 263 Pyriformis muscle, 46 Q Qnadrafcus femoris muscle, 46 Quadriceps, 47 — centre for, 232 Qualitative changes in irritability, 73 Quantitative changes in irritability, 73 Eachialgia, 260 Badiating pains, 260 Radicular neuritis, 119, 303 Railway spine, 661 Bamoa y Cajal, 53 Ranvier, nodes of, 62 Reaction, normal, 73 — of degeneration, 31, 32, 71 — — in infantile palsy, 403 — — mixed form, 32, 393 Rectal crises, 462 Rectum, centre lor, 245 Rectus femoris, 47 Redecussation in cord, 211 Red softening of cord, 348 Reflex action, 19, 238, 240, 262, 263 — < — cutaneous, 19 ^ — in nerve injury, 79 — ^ muscular, 20 — — two kinds of, in cord, 238 — arc, 19, 239 — centre, 19, 239 — paralysis, 665 — spasm, 264 Reflexes, deep, 20 — superficial, 19 latent period of, 24 Regeneration of fibres in cord, 358 — of nerves, 69 Regressive period in infantile palsy, 408 Reinforcement, 21 Representation of movements in cord, 230 Resistance in nerve phenomena, 54 Resisting power, deficiency in, 6 Reticular formation, lateral, 202 — — posterior, 203 Rheumatic neuritis, 82, 137, 145 Rheumatism of dorsal muscles, 320 Rhomboids, 35 Rigidity, clasp-knife, 265, 493 — in cord diseases, 256 — in progressive muscular atrophy, 641 Rolando, grey substance of, 206 Romberg's symptom, 449 Root pains, 260 — symptoms in compression, 393 — zone, 200 Boot-fibres, cause of, 224 Roots, anterior, 224 — distribution of, 225 — posterior, 225 S Sacral plexns, diseases of, 114, 116 Sartorius muscle, 232 Scapular muscles, 34, 231 I>"DEX. 689 ScTimidt, incision of, 63 Pcliultze, Max, observation of, 55 Schwann, white substance of, 62 — sheath of, 62 Sciatica, 123 Sciatic nerve, disease of, 116 Sclero