The diseases of the nervous system

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UNITED STATES OF AMERICA.

Preface

To add yet another to the vast number of text-books on nervous diseases which already exist, and most of which are admirably written, is a somewhat serious undertaking, and the question whether the want of such a book is really felt can be answered in the affirmative only with some diffidence. If, despite this, the author has ventured to enter the field with writers like Erb, Eulenburg, Strumpell, Seeligmiiller, Mobius, and others, some responsibility must rest upon the shoulders of his publisher, who has more than once assured him that there is still room for another text-book in addition to those already in our libraries. He was influenced, too, by the hope that here and there on certain points the treatment of the subject, by varying from that ordinarily adopted, might while rendering it more easily comprehensible to the beginner make the book none the less reliable as an adviser to those of wider experience. With this end in view, we have considered the manner of dividing the subject matter to be of no small importance, and have therefore chosen to discuss the diseases of the brain, those of the spinal cord, and those of the general nervous system separately, while diseases of the peripheral nerves, cranial as well as spinal, have been fully treated of by themselves. We shall not, as others have done before in treating of the cranial nerves, discuss one here, one there, and the peripheral nerves of the spinal cord partly in one place, partly in another, according as we are dealing with their motor or their sensory disturbances, but shall speak of the former and of the latter in the order that their anatomical position would indicate. In this way we shall be enabled to obtain a comprehensive view of them, which is undoubtedly highly desirable. To please all is impossible. Of course, one reader would wish that one point had been treated in this particular way and in that par- Cm;

IV PREFACE.

ticular place, while another would have fancied something totally different. About this we cherish no fond illusions. A systematic discussion of the sympathetic system, as well as of affections due to specific micro-organisms — e. g., tetanus, lyssa — we have not attempted, partly for other reasons, and partly because the space allotted to us would not allow of it. Further deviations from the usual course — e. g., the attempt to divide the functional neuroses into two classes, and to put tabes not among spinal diseases, but among those affecting the general nervous system — are sure to meet with sharp criticism, and we do not expect that the position we have assumed toward hypnotism and the treatment by suggestion will for the present meet with general acceptation. Every new and strange idea necessarily requires time to win its way and gain for itself a large circle of adherents. We hope it will be our pleasant task to record in a new edition (if such by good chance be called for) the assent of more of our professional brethren to this view. Finally, the list of references which we have inserted at the end of each chapter, thinking it would be of convenience to such of our readers as wish to study fully any particular point, this list, we confess, will not bear too severe a criticism ; naturally, we could not mention every work dealing with the subject ; for such a task neither the knowledge of the author nor the capacity of the book could suffice. Only the most important, and of these only the more recent, works could be quoted.

Only too well aware of his shortcomings, but convinced that he has set down concisely what he has learned from others and observed himself in an extensive hospital as well as private practice— convinced also that the illustrations, for which he has to thank the generosity of the publisher, will do much to enhance the interest of the text — the author bows willingly to the dictum of the old proverb,

Dr. Ludwig Hirt.

Breslau, September, 1889.

INTRODUCTORY NOTE.

The pleasure of introducing to the profession of this country a translation of a standard work is enhanced by the opportunity it affords of acknowledging how great is our debt to those — translators and publishers — who have made current in English the works of Trousseau, Niemeyer, Virchow, Cohnheim, and others. All recognize the necessity of teachers knowing the classical works in all languages, but of equal importance is it that the practitioners in all countries should have easy access by means of translations to the thoughts and experience, the ways and methods, of the masters of our art the world over. No better corrective exists to the vice of Philistinism — that narrow conceit of the special prominence of medicine in any one country — than a wide diffusion in all of the best works of each.

Early in 1890 my attention was called by Dr. Weir Mitchell to the first part of Prof. Hirt's Handbuch der Nervenkrankheiten, which he characterized as an exceptionally well arranged and thorough work on diseases of the nervous system. The completed work seemed in many respects so admirable a text-book that I wrote to Prof. Hirt and asked his permission to have it translated.

The arrangement of the subjects to which the author refers in the preface, though somewhat novel, is justifiable and entirely satisfactory ; and it is a distinct advance in classification to place tabes dorsalis and dementia paralytica among the diseases of the general nervous system, instead of in the sections on diseases of the cord and diseases of the brain respectively.

The fact which makes the work of value to the teacher, the student, and the practitioner is the graphic description of the anatomy and symptomatology of the different diseases. Where all is so good it is invidious to select, but the chapter on tabes vi INTRODUCTORY NOTE.

is an illustration of our author's lucid and, at the same time, thorough treatment of his subject. The various affections are treated of also from an advanced modern standpoint ; conflicting theories and passing observations are submitted to a wise criticism through which the author's own large and varied experience is very apparent.

An attractive aspect of the work is the excellent character of the illustrations, which, as they are in great part original, will be a pleasing relief to the hackneyed cuts which have for so long passed from book to book in English works.

Pursuing the via media in the important question of treatment, neither displaying the pessimism which too many maladies of the nervous system would seem to justify, nor an optimism so flagrant as to savor of quackery, Prof. Hirt is a safe guide in the highways and byways of neurotherapeutics.

And, lastly, I think the author has been fairly handled by his translators, who, bearing in mind the admonition of Dryden, " not to lackey by the side of his author, but to mount up behind him," have given a clear and interesting rendering of the original.

William Osler.

Baltimore, January, i8gj.

interna hemorrhagica, hematoma duras matris ■> II. — Inflammations of the soft membranes of the brain, leptomeningitis, purulent meningitis .......... 9

Part II

Chap. I. — Diseases of the olfactory nerve 24

II. — Diseases of the optic nerve 28

III. — Diseases of the nerves supplying the ocular muscles . . . .40

IV. — Diseases of the trigeminal nerve ........ 52

V. — Diseases of the facial nerve . 77

VI. — Diseases of the auditory nerve . 94

VII. — Diseases of the glosso-pharyngeal nerve . . . . . . . 105

VIII. — Diseases of the vagus (pneumogastric nerve) 108

IX. — Diseases of the accessory nerve 138

X. — Diseases of the hypoglossal nerve ........ 142

XI. — Simultaneous affection of several cranial nerves — Multiple paralysis of

the cranial nerves 150

Part III

I. The study of cerebral lesions with reference to their seat — Topical diagnosis

— Doctrine of localization ......... 164

Symptoms referable to cortical lesions ....... 166

Symptoms referable to lesions of the white matter of the hemispheres and

to lesions of the basal ganglia ........ 188

(vii)

yiii CONTENTS.

PAGE

II. The study of cerebral lesions with reference to their pathological nature —

Pathological diagnosis . . . . . . . ... .211

Affections of the brain due to disease of the blood-vessels . . . .213

A. Diseases of the cerebral vessels and their consequences . . . 213

1. Cerebral haemorrhage 215

2. Embolism and thrombosis of the cerebral arteries — Encephalo-

3. Endarteritis (syphilitica) 252

4. Dilatation of the arteries of the brain 254

5. The neuroses of the arteries of the brain (anaemia and hyperemia

of the brain) 255

B. Diseases of the cerebral veins and sinuses ...... 258

Inflammatory processes of the brain substance ...... 261

1. Purulent encephalitis — Brain abscess ....... 261

2. Nonsuppurative encephalitis and its consequences (" athetosis ") . 267

A. In adults 267

B. In children — Cerebral palsy of children — Hemiplegia infantilis

spastica — Polio-encephalitis 268

Appendix — Parasites of the brain ........ 303

Congenital diseases — Hydrocephalus — Meningocele — Porencephaly — Absence of certain parts of the brain . . . . . . 305

Diseases of the Spinal Cord 311

Part I

Chap. I. — Inflammations of the dura mater — Pachymeningitis spinalis . . . 313 II. — Inflammations of the soft spinal meninges — Leptomeningitis spinalis . 319 III. — Haemorrhage into the spinal membranes — Meningeal apoplexy — Pachymeningitis interna haemorrhagica ....... 323

PART II. Diseases of the Spinal Nerves 327

A. Diseases of the motor and sensory nerves 329

I. Diseases of the cervical nerves 329

Chap. I. — Lesions of the cervical plexus ...... 335

II. — Lesions of the brachial plexus ...... 338

II. Diseases of the dorsal nerves 360

III. Diseases of the lumbar nerves ........ 363

IV. Diseases of the sacral and coccygeal nerves 368

V. Neuritis involving several spinal nerves at the same time — Multiple

neuritis 385

B. Diseases of the trophic and vaso-motor nerves ...... 393

Appendix — Diseases of the muscles — Primary myopathies . . . 406

CONTENTS. ix

Part III. Page

Diseases of the Substance of the Spinal Cord 416

I. Consideration of spinal diseases with reference to their seat — Topical diagnosis 416

1. Lesions of the gray matter — Poliomyelitis ...... 422

Chap. I. — Poliomyelitis anterior acuta — Infantile spinal paralysis . 424 II. — Atrophia muscularis progressiva spinalis — Progressive muscular atrophy . . . . . . . . . 431

11. Lesions of the white matter of the spinal cord — Leucomyelitis . . 435

A. Primary lesions of the white columns 435

B. Secondary lesions of the white columns 439

in. Lesions of the gray and white matter of the spinal cord . . . 440

II. Spinal lesions regarded from their pathological aspect — Pathological diagnosis 451

I. Affections of the spinal cord due to diseases of the blood-vessels . . 451

A. Diseases of the arteries of the spinal cord and their consequences 451

1. Spinal haemorrhage — Hgemorrhagia (or apoplexia) medulla?

spinalis — Hsematomyelia 452

2. Embolism and thrombosis of the spinal arteries and myelo-

malacia 454

3. Endarteritis (syphilitica) 454

4. Dilatation of the spinal arteries . . . . . -455

5. Neuroses of the spinal arteries 455

II. Inflammatory processes in the substance of the spinal cord . . . 458

1. Purulent myelitis— Abscess of the spinal cord .... 458

2. The non-purulent myelitis 458

A. The acute form 458

B. The chronic form ......... 460

Hi. Spinal tumors 460

Appendix — Parasites of the spinal cord 462

IV. Congenital diseases — Hydrorrhachis — Spina bifida .... 463

PART I. Diseases of the General Nervous System without any Recognizable

Anatomical Basis — "Functional Neuroses" 471

First Group. — Neuroses which are wont to run their course without any essential implication of the general organism ....... 473

Chap. I. — Chorea — Chorea Sancti Viti — St. Vitus' dance — Ballismus — Melancholia saltans — Sydenham's disease 473

II. — Tetany — Tetanilla — Tetanus intermittens 484

III. — Paralysis agitans — Shaking palsy — Parkinson's disease — Chorea

procursiva 489 x CONTENTS.

PAGE

Second Group. — Neuroses in which the entire organism is more or less severely

Chap. I. — Neurasthenia — Nervous prostration ...... 497

II. — Hysteria 506

III. — Epilepsy — Falling sickness — Morbus sacer — Morbus comitialis . 532 IV. — Hystero - epilepsy — Major hysteria — Hypnotism — Treatment by

suggestion 561

PART II. Diseases of the General Nervous System with Known Anatomical

Basis 576

Chap. I. — Multiple sclerosis — Disseminated sclerosis — Insular sclerosis — Sclerose

en plaques — Sclerosis cerebro-spinalis disseminata sive multiplex . 576 II. — Tabes dorsalis — Locomotor ataxia — Posterior spinal sclerosis — Leuco-

myelitis posterior chronica 586

III. — Dementia paralytica progressiva — General paralysis of the insane —

General paresis — Softening of the brain 644

IV. — Syphilis of the general nervous system . . . . . . 656

Appendix — Intoxication paralyses 660

LIST OF ILLUSTRATIONS.

1. Cross-section through the cerebral cortex and its membranes .... 4

2. Anterior and middle portions of the base of the brain . . . . .24

3. Diagram showing the course of the optic fibres in the chiasm . . .28

4. Diagram showing the origin of the optic nerve (after Wernicke) . . . 30

5. Field of vision of the left and right eye (after Forster) 35

6. Field of vision of the left and right eye in left-sided hemianopia (after Gow-

ers) 36

7. Cross-section through the region of the ant. corpora quadrigemina . . .40

8. Diagrammatic longitudinal section through the pons with the nuclei of the

ocular nerves (after Gowers) ......... 41

9. Cross-section through the region of the tegmentum (after Schwalbe) . . 42

10. Cross-section through the pons (after Schwalbe) . . .' . . -43

11. Nuclei of the trigeminal nerve (after Schwalbe) ...... 53

12. Cross-section through the medulla oblongata (after Schwalbe) . . .54

13. Distribution of the sensory cutaneous nerves on the head . . . -74

14. Diagram showing the course of the facial fibres in the pons (after Schwalbe) . 78

15. Diagram showing the decussation of the fibres going to the extremities, and

of those going to the face, in the pons and medulla oblongata . . .84

16. Erb's diagram for facial paralysis ......... 88

17. Some of the so-called " motor points " on the face and neck . . . .92

18. Diagrammatic section through the medulla oblongata in the region of the

19. Cross-section through the medulla oblongata (after Schwalbe) . . . 109

20. Bilateral paralysis of the recurrent laryngeal 115

21. Recurrent laryngeal paralysis .......... 115

22. Paralysis of the recurrent laryngeal on the left side . . . . . 115

23. Paralysis of both posterior crico-arytenoids . . . , . . .115

24. Paralysis of the right post, crico-arytenoid . . . . . . .115

25. Paralysis of both internal thyro-arytenoids ....... 115

26. Paralysis of both internal thyro-arytenoids . . . . . . .115

27. Cross-section through the cervical cord ........ 138

28. Superficial origin of the cranial nerves ........ 143

29. Base of the skull with the emerging cranial nerves (after Henle) . . . 144

30. Cortical centres of the left hemisphere (after Gowers) ..... 145

31. Cross-section through the medulla oblongata (after Wernicke) . . . 145

32. Hemiatrophia linguae 146

33. Hemiatrophia linguae ........... 147

34. Pharyngeal and laryngeal electrode with arrangement for making and break-

ing the current (after Erb) 152

(xi)

x ii LIST OF ILLUSTRATIONS.

35. Facial expressions in progressive bulbar paralysis (after Leyden, Eichhorst) . 156

36. Cross-section through the upper portion of the medulla oblongata . . .158

37. The posterior (dorsal) aspect of the medulla oblongata 159

38. Right hemisphere (after Exner) 167

39. Left hemisphere (after Exner) 168

40. Convolutions and fissures of the lateral aspect of the brain (after Ecker) . 169

41. Convolutions and fissures at the base of the brain (diagrammatically after Ecker) 170

42. Convolutions and fissures of the median aspect of the brain .... 171

43. Convolutions of the island of Reil (J. R.) made visible by removing the oper-

culum 172

44. Topographical relations between the exterior of the skull and the surface of

the brain (after Ecker) 173

45. Wernicke's schema for the cortical mechanism of speech .... 176

46. 47. Lichtheim's schema illustrating the seven different forms of aphasia. . 179

48. Diagram showing the direct system of fibres (Flechsig, Mendel) . . .183

49. Course of the fibres from the internal capsule to the crus cerebri (diagram-

matic after Wernicke and Edinger) 189

50. Horizontal section through the hemispheres ....... 190

51. View of the ventricles on horizontal section (after Edinger) .... 191

52. Horizontal section through the brain, about a finger's breadth below that

represented in Fig. 51 (Edinger) ........ 192

53. Base of the brain (with the first portion of the spinal cord) .... 193 54-57. So-called " frontal sections " through the brain (after Edinger) . 194, 195 58. Points at which the Pitres-Nothnagel's sections are made .... 196 59-64. Pitres-Nothnagel's sections 197-199

65. Diagrammatic cross-section through the anterior corpora quadrigemina (after

Edinger) , 2co

66. Longitudinal section through the region of the corpora quadrigemina of a

human foetus twenty-eight weeks old (after Edinger) .... 201

67. Diagrammatic horizontal section through the decussation of the superior pe-

duncles of the cerebellum (after Edinger) 202

68. Sagittal section through pons and medulla oblongata (after Mendel) . . 203

69. Cross-section through the region of the ant. corpora quadrigemina . . 204

70. Diagram showing the decussation of the fibres going to the extremities, and

of those going to the face, in the pons and medulla oblongata . . . 205

71. The cerebellum seen from behind 206

72. Cerebellum seen from in front 207

73. The connections of the cerebellum 207

74. The anterior (lower) surface of the medulla oblongata 208

75. The posterior (dorsal) aspect of the medulla oblongata 209

76. Diagram showing the circle of Willis 212

77. The cortical distribution of the middle cerebral artery (after Charcot) . . 213

78. Frontal section through the cerebral hemispheres, one centimetre behind the

79. Cerebral artery from an apoplectic focus (after Cornil and Ranvier) . . 216

80. Miliary aneurism of a small artery of the lenticular nucleus (after Marchand) . 216

81. The large head electrode (covered with sponge) of Erb 242

82. Porencephaly 267

83. Hemiatrophy of the left side of the body, front 274

84. Hemiatrophy of the left side of the body, back 275

85. Hemiatrophy of the left side of the body from traumatism, front . . . 276

LIST OF ILLUSTRATIONS.

Xlll

86. Hemiatrophy of the left side of the body from traumatism, back . . . 277

87. Atrophy of the left upper and lower extremity 278

88. Atrophy of paralyzed side .......... 279

89. Atrophy of paralyzed side ; contracture of wrist ...... 280

90. Atrophy of paralyzed side ; contracture of ankle 282

91. Atrophy of paralyzed side ; contracture of ankle 283

92. Convulsive movements of the extremities ....... 285

93. Glioma telangiectaticum (after Ziegler) 28S

94. Papillary carcinoma in the third ventricle (after Ziegler) .... 289

95. Cysticercus racemosus (after Marchand) . ....... 304

96. Cross-section through the vertebral column and the spinal cord (diagram-

matical) (after Eichhorst) 313

97. Cross-section through the middle of the cervical enlargement in pachymenin-

gitis cervicalis hypertrophica (after Charcot) . . . . . .314

98. Position of the hand in pachymeningitis cervicalis hypertrophica (Charcot) . 316

99. Diagrammatic outline of the cervical and brachial plexuses (after Schwalbe) . 330

100. The superficial branches of the cervical plexus (after Hirschfeld and Le-

veille) 331

101. Deep dissection of the axilla, showing the brachial plexus (after Hirschfeld

102. Cutaneous nerves of the shoulder and of the upper arm (after Hirschfeld and

Leveille) 333

103. Cutaneous nerves of the forearm and of the palm of the hand (after Hirsch-

feld and Leveille) 333

104. Case of right-sided serratus paralysis in a man thirty-five years of age (after

Eichhorst) 339

105. The same case with the arms raised ........ 340

106. Position of the head in spasm of the splenitis capitis on the right side . . 341

107. Musculo-spiral paralysis ........... 342

108. Motor points of the musculo-spiral nerve and the muscles supplied by it . 345

109. no. The distribution of the cutaneous nerves of the arm and hand (after in. Distribution of the sensory nerves on the back of the fingers (Krause) . . 347

112. Motor points of the median nerve and the muscles supplied by it . . . 348

113. Motor points of the ulnar nerve and the muscles supplied by it 349

114. Motor points of the ulnar nerve ........'. 350

115. Claw-hand (after Duchenne) 351

116. Motor points of the musculocutaneous nerve and the muscles supplied

by it 351

117. Motor points of the brachial plexus ; Erb's supraclavicular point . . . 352 118-121. The manner in which a child whose erectores spinse are paralyzed gets

up from the ground (after Gowers) ........ 363

122. Diagrammatic outline of the lumbar and sacral plexuses .... 364

123, 124. Areas of distribution of the cutaneous nerves of the lower extremity

(after Henle) 365

125. Branches of the lumbar plexus (after Hirschfeld and Leveille) . . . 366

126. Deep nerves of anterior and inner part of the thigh (after Hirschfeld and

127. Cutaneous nerves of the leg and foot (after Hirschfeld and Leveille) . . 378

128. Distribution of the branches of the external popliteal nerve (after Hirschfeld

and Leveille) 378

XIV LIST OF ILLUSTRATIONS.

129. Motor points for the nerves and muscles of the anterior surface of the leg . 379

130. Motor points for the sciatic nerve and the muscles supplied by it . . . 380

131. Case of peripheral neuritis of the sciatic nerve, with shortening and atrophy

of the affected extremity 381

132. Case of peripheral neuritis of the sciatic nerve, with shortening and atrophy

of the affected extremity 382

133. 134. Contracture in the quadratus lumborum ....... 383

I35i T 36- Panarthritis with secondary multiple neuritis 388, 389

137. Case of myxoedema (after Charcot) ......... 399

138. Hemiatrophia facialis ........... 402

139,140. Cases of acromegaly (after P. Marie) 404,405

141. Erb's juvenile muscular atrophy (after Marie and Guinon) .... 408

142. Progressive atrophic myopathy (after Marie and Guinon) .... 410

143. Pseudo-hypertrophy of the muscles of the legs, with atrophy of the muscles

of the back (after Duchenne) 411

144. Absence of the forearms 412

145. The relations of the origin of the nerves to the bodies of the vertebras and

the spinous processes (after Gowers) 417

146. Scheme of the conducting paths in the spinal cord at the level of fifth dorsal

nerve (after Flechsig) 418

147. Cross-section through the spinal cord at different levels (after Quain) . .418

148. Reflex arc 419

149. Transverse section from the cervical portion of the spinal cord (after

Charcot) 424

150. 151. Progressive muscular atrophy (after Eichhorst) ..... 432

152. Ascending and descending degeneration in the spinal cord (after Gowers) . 440

153. Secondary ascending and descending degeneration in a transverse affection

of the upper dorsal cord (after Striimpell). ...... 440

!54) 155- Complete interruption of conduction of the spinal cord during life (after

Eichhorst) 447

156. Schema of the course of the nerve fibres in the spinal cord (after Brown-

Sequard) 450

157,158. Specimens of handwriting of patient with paralysis agitans . . 490,491

159. Position of hands and fingers in paralysis agitans (after Eichhorst) . . . 492

160. Position of the body in paralysis agitans ........ 493

161. Specimen of handwriting in a case of multiple sclerosis 577

162. Cross-section through the cervical enlargement of the spinal cord in a case of

multiple sclerosis (after Bramwell) 583

163. Hemiatrophy of the tongue in an otherwise perfectly healthy child . . 594

164. Specimen of handwriting in a case of tremor in tabes 599

165. Two cases of tabes (after Westphal) ........ 604

166. A case of Charcot's joint in a tabetic ........ 608

167. Erosion of the head of the humerus in tabes dorsalis (after Charcot) . .611

168. Normal humerus (after Charcot) 61 r

169. Skeleton of a tabetic foot (after Charcot) 612

170. Plantar flexion of the toes in the course of tabes ...... 614

171. Section through the cervical cord in a case of commencing tabes (after

Striimpell) 626

172. Section through the lumbar cord in tabes (after Striimpell) .... 626

173. Section through the cervical cord in a case of advanced tabes (after Striim-

pell) 626

LIST OF ILLUSTRATIONS.

XV

174. Suspension apparatus used in the treatment of tabes ..... 636

175. Specimen of handwriting of a patient (hat-maker) with a mercurial tremor . 666

176. Specimen of handwriting illustrating the tremor produced in a case by the

combined action of alcohol and mercury (V. Finkenstein, 4, 86) . . 667

177. Specimen of handwriting illustrating alcoholic tremor 668

178. Specimen of handwriting illustrating tremor senilis 669

DISEASES OF THE BRAIN AND ITS MENINGES, INCLUDING THE CRANIAL NERVES.

The study of brain diseases, we must confess, has not made the strides that might have been expected after the numerous and varied researches that the last decades have seen. For this our present very imperfect knowledge of the anatomy, and still more our doubts as to the physiological functions of the different parts of the brain must be held largely responsible. The structure as well as the physiological functions of the human brain are, up to the present time, so little understood that we are far from having any sure basis upon which to lay the foundations of a cerebral pathology. No small progress has been made from an anatomical standpoint through Selling's method of serial sections, a method which Meynert, Henle, Wernicke, and others have not been slow to use, in their admirable researches, to which important additions have been made by the embryological studies of Flechsig, and by the method of " arrested development " used by Gudden and his pupils (atrophy method; Degenerationsmethode, Schwalbe); but with all this we have only here and there single stones which we have not as yet been able to combine for the construction of a harmonious whole. Brilliant from a physiological standpoint as was the discovery of Fritsch and Hitzig (1870) of the electrical irritability of the cortex, and of the existence of motor regions therein, unexpected as were the results which the experimental method of Munk brought to light, extraordinary and interesting as are the conclusions based upon the clinical and post-mortem observations of Charcot and his school — all these, wide-reaching and admirable as they were, are far

2 DISEASES OF THE BRAIN.

from having given us a full understanding of the functions of the different parts of the brain, and an explanation of the disturbances to which they are subject. Constant and untiring work is still needed, and the best results are promised from the intelligent combination of clinical observation with pathological research. The pathology of the brain can not be better advanced than by the patient clinical observation of cases during life and a careful autopsy after death. In institutions where not only the fullest opportunities are afforded for clinical observation and for the systematic conduct of post-mortem examinations of the brain, but where also the best men are found to supervise the work, in these will cerebral pathology make the greatest strides.

We shall divide our description of cerebral diseases into three parts. In the first we shall take up the diseases of the meninges, in the second those of the cranial nerves, while the third will embrace the diseases of the brain in the stricter sense, i. e., those of the white and gray matter of the hemispheres and of the central ganglia.

PART I.

DISEASES OF THE MENINGES OF THE BRAIN.

The meninges are relatively more frequently affected by disease than the brain substance itself, and quite a considerable number of the cases which we commonly call diseases of the brain are really to be classed as affections of the meninges. Since these diseases can develop under the most varied conditions, and can be primary as well as secondary, they are of great practical importance, and we must try to distinguish most carefully between the different forms which they assume.

A clear understanding of the pathological processes in these diseases will be facilitated by some remarks upon the anatomy of the meninges.

The outermost, tough, fibro-tendinous membrane, called the dura mater, forms at the same time the inner periosteum of the cranial bones. It has an outer, rough, and an inner, smooth surface. For the nerves as they emerge from the skull this membrane supplies sheath-like coverings, among which that of the optic (vagina optici) is the most conspicuous. The dura consists of two layers, which at certain places separate, forming spaces (sinus durse matris). The cerebral layer sends two leaf-like processes into the cavity of the skull — one vertical, constituting the so-called falx cerebri (processus falciformis major), which extends from the crista galli to the internal occipital protuberance, and the so-called falx cerebelli, which penetrates between the two hemispheres of the cerebellum (processus falciformis minor) ; another horizontal, the so-called tentorium cerebelli, which is pushed in between the lower surface of the occipital lobes of the cerebrum and the upper surface of the cerebellum. Both together are called the processus cruciatus durse matris. The blood-supply of the dura is derived from branches of the meningeal arteries. That it possesses its own nerves is doubted by some (among them Luschka), confirmed by others (Ruedinger, Alexander). It is most probable, however, that it is the trigeminus which chiefly provides for the innervation of the dura.