Chapter XLVIII: Introduction: The object of the following essay is to give, as far as (4)

Prévost[214] has since formulated the following laws for cases of hemiplegia: "I. When the hemiplegic looks toward his lesion and away from his paralyzed side, the lesion is hemispherical. II. If he looks toward his paralyzed side, the latter is situated in the mesencephalon." This statement coincides with the facts reported by Hughlings-Jackson, Charcot, and many other observers. Nothnagel[215] admits that this is the rule, but quotes as an exception to it a case of his own where, with right hemiplegia and head turned to the right, the eyes were turned to the left, the autopsy showing an extensive patch of softening in the left hemisphere which involved the frontal convolutions, the central convolution, and the adjacent white substance. In addition, he cites Bernhardt as giving other exceptional cases which, in his own judgment, "considerably diminishes the diagnostic value of the phenomenon." Landouzy and Coignt[216] have attempted to define still more clearly the diagnostic value of the associated movements of the head and eyes, and, while they admit the correctness of these laws of hemiplegic paralysis, they add that in convulsive {783} cases in which there are symptoms of irritative lesions the above rules are reversed. To explain such cases they lay down the following rules: first, that if the patient looks toward his convulsed side the lesion is situated in the hemisphere of the opposite side; and second, if he looks away from his convulsed side (or toward the lesion) there is an irritant lesion of the mesencephalon.

[Footnote 214: _Thèse de Paris_.]

[Footnote 215: _Topische Diagnostik der Gehirnkrankheiten_, p. 580, 1879.]

[Footnote 216: _Thèse de Paris_, 1878.]

NYSTAGMUS.--This is a term applied to a periodic type of involuntary oscillatory or rotatory movements of the eyeballs. The oscillatory are due to rapid alternate contraction of the straight muscles, while the rotatory indicate either similar actions of the oblique muscles alone or in conjunction with the straight. The oscillatory motions are usually horizontal, but instances of vertical nystagmus occur, as in the case recorded by Soelberg Wells.[217] Nystagmus may be either congenital or acquired; the latter variety being much the more frequent form of the affection. Congenital nystagmus is usually associated either with cataract or imperfect development of the optic nerve and retina. It is a very frequent accompaniment of albinism and pigmentary retinitis. We often see the acquired form arise during the first few months of life, when the child in its effort to see is hindered by corneal or lenticular opacities resulting from ophthalmia neonatorum. One of the most interesting of the acquired forms is that which occurs amongst coal-miners, rendering a considerable number of those thus affected unfit for work. At first the symptoms are that the lights in the mines and the objects on which the patients endeavor to fix their attention begin to dance, this being accompanied by a sensation of dizziness and discomfort. In the first part of the attack they disappear when work is stopped, and the miners come up into the daylight; but if work be persisted in they become permanent and exaggerated. When the nystagmic motions have ceased, they may often be called into activity by placing the patient in a dark room and getting him to direct his eyes to a candle held above the horizontal line of the field of vision. The motions are usually lateral, or in some cases the centre of the cornea describes an ellipse or circle which causes the patient to see a ring of light. It has been observed to occur much more frequently in those working in shafts where there is a good deal of fire-damp; which has caused some writers to assert that the nystagmus has been dependent upon the action of the gas. This view would seem to receive some support from an instance reported by Bright of nystagmus, in a case of suffocation from the fumes of burning coals, which he attributed to cerebral pressure. In these cases it is more probably due to fatigue of the eye and its nerve-centres in the endeavor to see in the dim light and strained position which the miner is often obliged to maintain, which is intensified by the enfeeblement of the nerve-centres due to the action of the gas: these, associated with the diminution of the light caused by the wire gauze of the safety-lamp, would further increase the strain in those obliged to work in the shafts pervaded with fire-damp. The statements of Dransart,[218] founded on the examination of a large number of miners, probably give a correct idea as to the frequency of the affection. He states that among 12,000 workmen employed by one company, there were 30 under treatment for nystagmus, which would give about two and a half patients per thousand. In any form of nystagmus the motions of {784} the eyes usually become more rapid when they are used for near work. According to Nagel,[219] excessive convergence will at times cause a temporary cessation of all nystagmic motion; and he further proved this by putting extra strain on the interni by means of prisms with their base out. The true pathology of the various forms of nystagmus is still imperfectly known. Arlt[220] supposes that there is a rapid repetition of reflex movements in the endeavor to attain distinct vision in those forms which develop on account of corneal and lenticular opacities. He explains this by the supposition that the retinal impression is strengthened by the same retinal areas being rapidly and repeatedly subjected to the action of the rays of light from the same object, while a longer period of fixation would cause retinal fatigue and blur; showing the same principle by reminding us that our perceptive powers for a test object, upon first being brought into view at the periphery of the field of vision, are much stronger when the object is shaken than when it is brought quietly toward the fixation-point. Some forms of the affection, however, are manifestly due to fatigue of the nerve-centres, and have been by some authors placed in the same category as writers' cramp. For its causation we would naturally look for the anatomical changes either in the cortical centres for the eye-muscles or in the nuclei of the third and sixth pairs. Vulpian[221] states that wounds of the medulla in dogs cause nystagmus, and Schiff asserts that wounds of the white substance of the cerebellum near the peduncles give rise to the same phenomenon; while Ferrier has produced it by the influence of electricity on the cerebellum of apes. Cohn[222] records a case of gunshot wound of the right parietal bone (near the angular gyrus) which produced nystagmus. Merkel's case, occurring in a patient with embolism of the artery of the fissure of Sylvius, would also point to lesion near the angular gyrus. Stintzing[223] gives a case where there was thrombosis of the basilar and Sylvian arteries. Oglesby[224] relates two cases where nystagmus came on suddenly with dilatation of the pupils, the autopsies showing a clot which pressed on the medulla. Fienzal[225] also gives a case where there was a tumor in the left peduncle of the brain. It is often seen during epileptic convulsions. According to Raehlmann,[226] the motions of both eyes are under the control of psychic centres which regulate them according to the necessities of vision: for Willbrand[227] it is a sign of weakness of the voluntary cortical centres which fail to regulate the reflex activity of the middle brain and cerebellum. The latter author shows that the extent of the field of vision is increased in the direction of the oscillations in those cases where direct vision is not much impaired, while there is marked contraction of the field in cases where the direct visual acuity is much diminished. He also states that there is contraction of the field in the nystagmus of miners, which is greater during the intervals of the paroxysm than during their occurrence, and, further, that the contraction is greater where the case is one of long standing.

[Footnote 217: _Lancet_, 1871, p. 662.]

[Footnote 218: _Annales d'Oculistique_, 7, 82, p. 177.]

[Footnote 219: _Graefe u. Saemisch_, vol. vi. p. 226.]

[Footnote 220: _Krankheiten des Auges_, Bd. iii. p. 335.]

[Footnote 221: _Comptes Rendus de la Société de Biologie_, 1861 (quoted by Robin, p. 157).]

[Footnote 222: _Schussvorletzungen des Auges_, p. 19.]

[Footnote 223: _Jahresbericht f. Ophth._, vol. xiv. p. 306.]

[Footnote 224: _Brain_, vol. iii., 1880.]

[Footnote 225: _Trans. Internat. Congress_, at Milan, 1881, p. 126.]

[Footnote 226: "Nystagmus und seine Aetiologie," _A. f. O._, xxiv., 4, p. 237 (1878).]

[Footnote 227: _Klin. Monatsblätter f. Augenheilkunde_, vol. xvii., 1879, pp. 419-438 and 461-480.]

{785} In some rare cases nystagmus may be produced at will. Raehlmann,[228] Lawson,[229] Benson,[230] all report cases of the voluntary type. In one of those given by Lawson the patient (a gentleman in good health) "first made his eyes steady, and then set both into rapid lateral motion--so rapid that the outline of the cornea was completely lost to view." Zehender[231] observed it in a case of a twelve-year-old boy, where he was able to produce it by the instillation of a strong solution of eserine. Charcot states that ordinary nystagmus is a valuable symptom of disseminate sclerosis, and that it is present in about half of these cases, while it is exceptional in locomotor ataxy. "In some patients the look is vague until the eyes are made to fix some object, when the nystagmus develops."

[Footnote 228: _Loc. cit._]

[Footnote 229: _R. L. O. H. Reports_, vol. x. p. 203.]

[Footnote 230: _Ibid._, vol. v. p. 343.]

[Footnote 231: _Klin. Monatsblätter f. Augenheilkunde_, vol. xviii., 1879, p. 127 (note).]

According to Hammond, in disseminate sclerosis, nystagmus may be the only symptom for the period of a year before other symptoms develop. Moos[232] speaks of oscillatory movements of the eyes in Menière's disease, and Schwalbach[233] describes them in a case of purulent catarrh of the middle ear where they could be produced either by syringing or by pressure on the mastoid process.

[Footnote 232: _Arch. f. Augenheilkunde und Ohrenheilkunde_, vii. 2, p. 508.]

[Footnote 233: _Deutsches Zeitschrift f. prakt. Med._, No. 2, 1878.]

Affections of the Fifth Pair.

HERPES FACIALIS.--Herpes facialis frequently appears on the lips and angles of the mouth, and occasionally in the eye and its appendages. When upon the conjunctiva or cornea, it commences as clear watery vesicles, usually in groups, which soon burst and leave open ulcers looking very much like abrasions or scratches of this membrane. They usually occur in successive crops after fevers, especially pneumonia, although at times they may appear without any assignable cause. They are also slow to heal, but are not dangerous to the eyesight, except where they give rise to purulent infiltration leading to hypopyon.

HERPES ZOSTER OPHTHALMICUS.--Herpes zoster ophthalmicus is a far more formidable affection. The eruption, as is well known, follows the distribution of the divisions of the ophthalmic branch of the trigeminus, and when the eyeball is affected the sight is always threatened. Clear watery blisters form on the cornea, which soon burst, the exposed tissue taking on purulent infiltration, while pus is not infrequently deposited in the anterior chamber. These ulcers are slow to heal under the most careful treatment, which, as a rule, consists in washing with disinfecting solutions and applying a bandage, etc. There is almost always iritis, as evidenced by the sluggish pupil and at times by marked synechiæ.

The burning and pricking pain at the seat of eruption is marked, and there is severe neuralgia in the temple, forehead, and side of the nose. The intensity of the iritis varies considerably in different cases, and, although some terminate favorably, having had but few and slight symptoms, yet the one case reported by Noyes, where it led to cyclitis, followed by shrinking of the eyeball, which ultimately gave rise to {786} sympathetic irritation of the fellow-eye, shows how serious its consequences may be. Permanent opacities of the cornea are not infrequent. The disease is, fortunately, a rare one. It usually comes on either in middle or declining life, although Wadsworth has reported a case in a child four years old. The cornea becomes anæsthetic, both in the ulcers and over the rest of its surface, a long time often elapsing before any of its sensibility is regained. Horner[234] was the first to demonstrate that the corneal ulcers originated in vesicles, and the very great diminution of intraocular pressure in the affected eyeball, and also to show the marked difference in the temperature of the skin of the two sides. The temperature on the affected side is usually one and a half to two degrees higher than on the other side, while the cutaneous sensibility is markedly diminished; as, for instance, the æsthesiometer might give twelve lines on the healthy forehead as against twenty-two lines on the diseased side, and the superciliary ridges and the upper eyelid on the normal side might give respectively nine and five lines as against seventeen and seven lines on the affected side. In the cases which the writer has had an opportunity of studying he has found similar variations in intraocular tension, temperature, and sensibility. Hutchinson[235] thinks that the affection of the nasal branch is always accompanied by inflammation of the eyeball, and says: "Thus far, I have never seen inflammation of the whole side of the nose without witnessing inflammation of the eye;" while Bowman[236] says that he has "not found affections of the eyeball to occur, especially in those cases of ophthalmic zoster in which the eruption followed the course of the nasal branch." Wadsworth[237] gives a case where the entire side of the nose was involved, the eyeball and conjunctivæ not being affected. He suggests that possibly the explanation in these cases is an anomaly of distribution described by Turner, where the side of the nose is supplied by a long, slender infratrochlear branch. Bowman,[238] although realizing that peripheral excitement of sensory nerves may originate in a central or reflected source, and induce tenderness and redness in the parts supplied by them, yet nevertheless holds that ophthalmic zoster is a peripheral disease, having its primary seat in the branches of common sensation, the nerves probably becoming inflamed in the more superficial portions of their trunks, as the eruption succeeding as an extension of vascular excitement to the cutaneous tissue: he thus explains the tenderness of the skin before it reddens and the often lasting alteration of sensibility. In reference to whether the neuritis causing the eruption is an ascending or descending one, the only two careful autopsies that give answer with which the writer is familiar are those of Wyss and of Weidner, where both show extensive changes in the nerve-centres. The latter, made five years after the attack, showed cicatricial shrinking of the ganglion of Gasser and of the root of the nerve between it and the medulla; while that of Wyss, made within two weeks of the outbreak of the affection, showed that the entire ophthalmic branch of the trigeminus was thickened, reddened, softened, and surrounded by extravasation of blood from the entrance of the orbit up to the ganglion of Gasser; while the other branches of the trigeminus were normal in size and {787} appearance. The Gasserian ganglion itself was enlarged and bright red, while that of the other side of the head was yellowish-white. As is well known, zoster in other parts of the body not infrequently affects the two sides simultaneously; and there are recorded cases where it has twice attacked the same locality, but the writer is not familiar with any such facts as regards ophthalmic zoster.

[Footnote 234: _Klinische Monatsblätter f. Augenheilkunde_, 1871, p. 321.]

[Footnote 235: _R. L. O. H. Rep._, 1866, pp. 191-215.]

[Footnote 236: _Ibid._, 1867.]

[Footnote 237: _Trans. of Amer. Oph. Soc._, 1874.]

[Footnote 238: _Loc. cit._]

NEURO-PARALYTIC OPHTHALMIA.--In 1822, Herbert Mayo[239] showed that section of the fifth nerve within the cranium produces insensibility of the eye; and Charles Bell[240] in 1830, while recognizing this fact, maintained that "when that sensibility is destroyed, although the motions of the eyelids remain, they are not made to close the eye, to wash and clear it, and consequently inflammation and destruction of that organ follow." Since that time the subject has been a favorite theme with both clinicians and physiologists, but opinions as to its cause have been a good deal divided. While, perhaps, a majority, with Bell,[241] Snellen,[242] Kondracki,[243] Gudden,[244] Senftleben,[245] and others, hold that the inflammation of the cornea is of traumatic origin, many writers--amongst whom may be mentioned Longet,[246] Graefe,[247] Meissner,[248] Schiff,[249] and Eckhard[250]--assert that it is caused by the impaired action of the trophic fibres of the nerve; and again others, such as Ferrier,[251] Balogh,[252] and Buchmann,[253] maintain that the inflammation is peripheral, consequent upon the drying of parts of the cornea. Clinically, soon after the occurrence of complete palsy of the trigeminus, there is an interstitial punctate keratitis, which makes the cornea so cloudy that the motions of the iris are with difficulty observed, this being accompanied by conjunctival and ciliary injection. The symptoms, especially where the paralysis is incomplete, are often much alleviated by maintenance of careful closure of the lids and repeated washing of the eye, which protects the enfeebled tissue from the action of foreign bodies. Success is not, however, always obtainable, for occasionally, even with the most complete protection of the eye, eventual sloughing of the cornea cannot be prevented. This is not a usually-accepted doctrine, but the writer is convinced[254] of its truth by a case seen within a week of the commencement of the disease, in which the cornea was not yet ulcerated, where the most sedulous care in cleansing the eye and protecting it from external irritants did not prevent the necrosis and perforation of the central part of the cornea. Since then other cases of similar import have been published. Quaglino[255] gives an instance where complete ptosis shielded the eye from all gross insults, but where, nevertheless, a central slough of the cornea formed. Laqueur[256] also found {788} that the cornea sloughed in spite of the most careful protection. In all other cases where the cornea is exposed to air and external irritants, as in lagophthalmos or excessive exophthalmos, the case is quite different, the consequent inflammation being much better borne. While this is a fact more or less familiar to all clinicians, it is nowhere better shown than in the case of Horner,[257] where there was caries of the petrous portion of the temporal bone and complete paralysis of the facial nerve. Two years later the trigeminus was attacked, and then for the first time ulceration occurred in the hitherto sound cornea. Hirschberg[258] describes neuroparalytic keratitis and panophthalmitis consequent upon a neurectomy of the infraorbital nerve, and quotes Langenbeck as relating a similar case after section of the supraorbital nerve.

[Footnote 239: _Anat. and Physiol. Commentaries_, London, 1822, No. 2, p. 5.]

[Footnote 240: _Nervous System of the Human Body_, London, 1830, p. 207.]

[Footnote 241: _Loc. cit._]

[Footnote 242: _Virchow's Archiv_, Bd. xiii. S. 107, 1850.]

[Footnote 243: _Nagel's Jahresbericht_ (Lit. 1873), p. 266.]

[Footnote 244: _Idem._]

[Footnote 245: _Virchow's Archiv_, Bd. lxv. Heft. 1, pp. 69-99.]

[Footnote 246: _Anatomie et Physiologie du Système nerveux_, t. ii. p. 161, Paris, 1842.]

[Footnote 247: _Arch. f. Ophthalmologie_, Bd. i. Abth. i. S. 306-315.]

[Footnote 248: _Henle und Pfeuffer's Zeitschrift_ (3), xxix. p. 96 (quoted by Soelberg Wells).]

[Footnote 249: _Ibid._, p. 217 (also quoted by Wells).]

[Footnote 250: _Centralblatt f. Med. Wiss._ (cited by Nagel, Literature, 1873).]

[Footnote 251: _Nagel's Jahresbericht_, (Lit. 1876), p. 51.]

[Footnote 252: _Ibid._]

[Footnote 253: _Ibid._, 1883, p. 153.]

[Footnote 254: Norris, "Case of Paralysis of the Trigeminus, followed by Sloughing of the Cornea," _Trans. Amer. Ophth. Soc._, 1871, pp. 138-141.]

[Footnote 255: _Nagel's Jahresbericht_ (Lit. 1874), p. 26.]

[Footnote 256: _Klinische Monatsblätter f. Augenheilkunde_, 1877, p. 228.]

[Footnote 257: _Nagel's Jahresbericht_ (Lit. 1873), p. 267.]

[Footnote 258: _Berliner klinische Wochenschrift_, 1880, S. 169; _Sitzung der Gesell. f. Psych. und Nervenkrankheiten_, 10 März, 1879.]

INJURIES OF THE FIFTH PAIR.--Although daily clinical experience shows us how promptly irritation of the sensitive branches of the trigeminus are followed by symptoms of reflex action in the eye--as, for instance, a cinder in the conjunctiva will cause contraction of the pupil, or a sharp pinch of the temple will at times cause pupillary dilatation--nevertheless, instances of impairment of the eyesight due to injury of the branches of the infraorbital or supraorbital nerves, and to this alone, are of rare occurrence. Sympathetic ophthalmia is the exception in which we too frequently see inflammation of one eye cause severe and often irreparable damage to its fellow. Scattered through ancient and modern surgical works there are many interesting and well-attested cases of impaired vision, some of which should be excluded on account of the want of proper evidence, which is now obtained from testing of the acuity and field of vision and ophthalmoscopic examination. Erichsen[259] cites cases from Hippocrates, Fabricius Hildanus, and La Motte where amaurosis was produced by a wound of the brow. Chelius[260] gives a case from similar injury, while Wardrop[261] narrates three instances--one of wound of forehead, one from a blow on it with a ramrod, and one from an injury by a fragment of shell. The same author calls attention to the fact that amaurosis is more readily caused by wounds and injuries of the supraorbital and infraorbital nerves than from complete division of them. The various neurotomies and neurectomies performed upon the supraorbital branch since his day bear witness to the accuracy of his deduction. The same author quotes Morgagni as saying that Valsalva has seen amaurosis follow a wound of the lower lid which has been inflicted by the spur of a cock. Morgagni relates a similar case where the injury was inflicted by the broken glass from the windows of an upset carriage; and Beer reports a similar case of amaurosis from wound of the cheek. Guthrie[262] remarks that "when the eye becomes amaurotic from a lesion of the first branch of the fifth pair of nerves, the pupil does not become dilated; the iris retains its usual action, although the retina may be insensible and the vision destroyed." More recently, Rondeau[263] {789} gives two cases, one of which caused lachrymation, photophobia, and eventual atrophy of the eye on the affected side, followed, fifteen years later, by loss of the fellow-eye from sympathetic ophthalmia, which had been produced by degenerative changes taking place in the shrunken bulb; and a second, in which a wound of the left brow became painful eight days after the receipt of the injury, and where pains became more severe as the wound cicatrized: in this latter case the left eye became foggy in three weeks, and soon sight was entirely lost, whilst six weeks after the accident there was dull pain in the right eye, with a sensation of cloudiness and a gradual development of photophobia in it. By local bloodletting, which caused the photophobia to rapidly yield, and a derivative and alterant treatment, the patient's right eye was so far improved that fifteen days later he could find his way about with the left eye, and could see to read with the right. Ophthalmoscopic examination showed in the left eye a serous swelling of the retina which entirely obscured the margin of the discs and gave the whole fundus a grayish tint, the veins being much enlarged and very tortuous. The right eye showed similar changes, though less developed.

[Footnote 259: _Loc. cit._, pp. 233-261.]

[Footnote 260: South's translation of Chelius's _System of Surgery_, vol. i. p. 430.]

[Footnote 261: _Morbid Anatomy of the Human Eye_, vol. ii. pp. 180, 181, London, 1818.]

[Footnote 262: Quoted by White-Cooper, _Injuries of the Eyes_, London, 1859, p. 92.]

[Footnote 263: _Des Affections oculaires Reflexes_, Paris, 1866, pp. 53, 54.]

Affections of the Sixth Pair.

The extremely limited distribution of the sixth pair of cranial nerves renders the clinical study of their pathology comparatively simple. The eye supplied by the paralyzed muscle turns inward to an extent corresponding to the degree of loss of power in the paretic muscle plus the energy of its opponent rectus internus. The image of the object fixed by it falls, therefore, to the inner side of the macula lutea, and, being projected outward, causes a double vision, in which the image of the deviated eye appears to be in the temporal field of the affected eye (homonymous diplopia). When the healthy eye is covered and the patient endeavors to fix any near object with the paralyzed eye, it will be found that (as in all other cases of peripheral paralysis affecting any of the extra-ocular muscles) the secondary deviation of the sound eye is considerably greater than the primary deviation of the affected one; this being accounted for by the fact that the amount of consentaneous innervation which is sufficient to cause a small motion in the paretic muscle will produce a marked effect in the sound one.

Paralysis of the external rectus is quite common, and is either transient or permanent. The former variety is often put down as rheumatic, when it is really a symptom of tabes dorsalis. The permanent paralysis is frequently an accompaniment of the affections of the base of the brain: when these are located in the middle fossa of the skull it is often associated with paralysis of the facial. If hemiplegia be present, the lesion is usually situated farther back toward the exit of the nerve from the pons. Graux[264] and Ferréol have called attention to a form of paresis which results from disease of the nucleus of the sixth pair. In this form, owing to the affection of the filament which the nucleus of the sixth nerve gives to the nucleus of the third nerve, which is distributed to the internal rectus of the other side, the amount of the secondary deviation is much {790} diminished, and there is more or less the appearance of an ordinary concomitant convergent squint (where, as is well known, the excursions of the two eyes are nearly equal). In one case, where the autopsy showed that a small tubercle had been developed at the junction of the medulla and pons, just beneath the surface of the fourth ventricle, there was no other symptom than this conjugate deviation of the eyes. In another case, in which there was hemiplegia (hemiplégie alterne), a tubercle was found higher up in the pons, bulging into the fourth ventricle. In addition to the conjugate deviation of the eyes already mentioned, Graux and Ferréol believe that this central form of paralysis is distinguished by its gradual access, slow development, and persistence. They say that in pure cases of lesion of the nucleus it is characterized by the absence of all other symptoms, and still further assert that in those cases in which it is but partially involved the accompanying symptoms are either complete facial paralysis or alternate hemiplegia.

[Footnote 264: _Thèse de Paris_.]

Affections of the Seventh Pair.

Loss of power in the orbicularis palpebrarum, and consequent lagophthalmos, is frequently encountered as part of paralysis of the facial nerve. Where the paralysis is complete, it prevents closure of the eyelids. Variation in the size of the palpebral fissure is, however, by no means abolished, for, owing to relaxation of the levator palpebrarum, the fissure diminishes when the patient looks down, but is increased by the activity of this muscle when he looks up.

BLEPHAROSPASM.--Spasmodic closure of the lids is frequent in phlyctenular conjunctivitis and in many corneal and conjunctival affections. It is evidently reflex in its origin, and often entirely out of proportion to the amount of conjunctival or corneal disease. A foreign body under the lids will frequently give rise to a similar state of reflex spasm. We also encounter a greater or less degree of twitching of the lids as part of general or local chorea.

Affections of the Twelfth Pair.

BULBAR PARALYSIS, LABIO-GLOSSAL LARYNGEAL PARALYSIS.--Affections of the eye and its appendages are rather exceptional in this form of disease. In one case Galezowski describes unilateral atrophy of the optic nerve, and Dianoux[265] bilateral atrophy in another. In the latter the atrophy came on after partial paralysis of the lips and of the muscles of deglutition, it being preceded by paralysis of the right external rectus. Hallopeau[266] quotes a case from Wachsmuth where there was partial paralysis of the facial which rendered the face immobile and effaced its wrinkles, allowing the lower lid to fall. He cites also a case of Hérard in which there was amblyopia and partial ptosis. He justly remarks that such phenomena indicate an extension of the lesion from the nucleus of the twelfth pair to other parts of the central nervous system. {791} The pupils are sometimes described as contracted, more rarely as dilated. Leeser quotes Leube[267] to the effect that "paralytic myosis, when it occurs in bulbar paralysis, is generally a sign that it is complicated either by progressive muscular atrophy or with sclerosis of the brain and spinal cord."

[Footnote 265: Quoted by Robin, _Troubles oculaires dans les Maladies de l'Encephale_, p. 335.]

[Footnote 266: _Des Paralysies bulbaires_, Paris, 1875, p. 41.]

[Footnote 267: _Deutsches Archiv f. klin. Med._, Bd. viii. pp. 1-19, quoted by Leeser, p. 94.]

Mental Affections.

It is admitted by all observers that affections of the pupillary branch of the third pair, such as mydriasis, myosis, and inequality of the pupils, are of comparatively frequent occurrence among all classes of the insane. There is the widest difference of opinion as to the percentage of cases in which it occurs: thus, Nasse out of 229 cases found 146 (64 per cent.) with difference in the size of the pupils, while Wernicke found 24 per cent. in the Leubus Asylum, and only 13 per cent. in the Breslau Institute. The latter author has attempted to classify the pupillary lesions into three groups:

I. Mydriasis, with loss of accommodation, where the pupil does not react to light nor with increased convergence of the eyes.

II. Where the pupillary difference is slight and the irides less prompt than normal in reaction to light, all difference of the pupils disappearing upon convergence of the eyes.

III. In which the irregularity is still less, the narrower pupil being absolutely insensitive to light, but prompt in responding to convergence, while the more dilated pupil acts promptly in obedience to both light and convergence.

In the first group there is some lesion in the course of the third pair; in the second, some lesion of the sympathetic either in the cilio-spinal centre or in its unknown intracranial distribution; whilst in the third, which is not so readily explained, there is possibly an affection of those fibres which pass from the third pair to the optic nerve. Foerster[268] states that he has frequently seen cases where at different times the same pupil under similar circumstances showed different diameters; also asserting that variation in the relative sizes of the two pupils sometimes occurred within a few days or weeks. He also maintains that in many cases the occurrence of inequality in the pupils precedes and presages the occurrence of insanity; and as a marked example of it he quotes the case of a friend and colleague who observed this phenomenon in himself. This person was well aware of the theories on the subject, and while yet of sound mind jokingly remarked that on account of this inequality of pupils having set in, he thought of taking up his quarters in an insane hospital. A few years later he actually died insane in the Leubus Asylum. Myosis is said to be frequent in states of mental exaltation. Seifert asserts that when it is accompanied by acute mania general paralysis will sooner or later ensue. Griesinger asserts that the same thing occurs in chronic mania. As regards the changes in the optic discs in the insane, we find usually recorded either a low grade of neuritis or of atrophy: according to Leber[269] this atrophy is histologically similar to that occurring in gray degeneration of the nerves. The outer strands are {792} usually those most affected. Indeed, as far as these obscure diseases are at present understood, there is no good reason why any changes should be found in the optic nerves except the congestion which accompanies acute or subacute mental disease and the nerve-degeneration of various grades which might be expected to be found in all worn-out lunatics. Illusions and hallucinations referable to the sense of sight are not uncommon in the insane, and are perhaps due to degenerative changes in the visual centres. In classifying such cases for study of the intraocular changes most writers place them under the following heads--viz.: general paralysis, dementia, mania, and melancholia,[270] the account of the changes in the eye-ground and the proportion of cases in which they occur being found to vary greatly.

[Footnote 268: _G. u. S._, vol. vii. p. 227.]

[Footnote 269: _A. f. O._, xiv., 2, p. 203.]

[Footnote 270: Noyes, "Ophthalmoscopic Examination of Sixty Insane Patients in the State Asylum at Utica," pp. 6 (extra copy from _Amer. Journ. of Insanity_, Jan., 1872).]

GENERAL PARALYSIS.--Almost all agree that in this form of the disease we frequently have gray degeneration of the optic nerve, with pupillary symptoms which strongly resemble those found in tabes dorsalis, in some instances the autopsy showing the same location of spinal changes which characterizes the changes seen in locomotor ataxia.

DEMENTIA.--In chronic dementia Albutt found either hyperæmic or atrophic changes in the disc in 23 out of 38 cases. Noyes[271] found hyperæmia in 18 cases, and infiltration of the optic nerve and retina in 12. Jehn and Klein were unable to find changes in the discs of any of the cases which they examined.

[Footnote 271: _Idem._]

MANIA.--Albutt found the discs hyperæmic except in one case examined during a paroxysm, in which they were pale. Out of 20 cases of acute mania, Noyes[272] found 14 which showed hyperæmia of the discs; the discs of the remaining 6 were either anæmic or normal, these latter cases all being of short duration (less than three months); the 6 cases of chronic mania had eye-grounds which showed no lesion, while the other 3 exhibited hyperæmic or inflammatory changes.

[Footnote 272: _Loc. cit._]

MELANCHOLIA.--In Noyes's examination 4 out of 5 cases had healthy eye-ground, and 1 moderate hyperæmia and striation. Jehn found hyperæmia in every one of 40 cases examined, 2 of these having decided neuritis, which he supposed to be due to meningeal change.

Spinal Cord.

INJURIES TO THE SPINE.--Physiologists have frequently shown that pupillary and other eye-symptoms may be produced by experimental injury to the spinal cord of animals, which would lead us to naturally expect analogous results in man in cases of spinal fracture and injury. This subject has received great attention in England, where spinal injury from railway accidents appears unusually frequent. Albutt[273] tells us that it is tolerably certain that disturbance of the optic nerve and its neighborhood is seen to follow disturbance of the spine with sufficient frequency and uniformity to establish the probability of a causal relation between the two events. Erichsen,[274] who has collected his large clinical experience {793} into a book on _Concussion of the Spine_, after citing Plutarch to show how Alexander the Great was in danger of losing his eyesight from the blow of a heavy stone on the back of the neck, gives 53 cases (not tabulated with this view by the author), of which 49 were apparently undoubted cases of spinal injuries: of these, 13 (36 per cent.) showed decided eye-symptoms. Erichsen says: "My experience accords fully with that of Albutt. I found that in the vast majority of cases of spinal concussion unattended by fracture or dislocation of the vertebral column there occurred within a few weeks distinct evidence of impairment of vision." As enumerated by this author, these symptoms consist of difficulty of seeing in dim light, blurring and running together of the letters, and at times (in the early stages) slight diplopia. Later, there is photophobia, with contraction of the brow, which gives a peculiar frown, and at times an injection of the conjunctiva; these symptoms often being accompanied by muscæ volitantes and photopsia. He agrees with Albutt in attributing these to an ascending meningitis, while Wharton Jones considers that the eye symptoms are better accounted for by the action of the cilio-spinal centre and the sympathetic filaments springing from the dorsal and cervical cord. Wharton Jones[275] lays stress upon the undue retention of after-images and upon the small amount of comfort which a positive (convex) glass gives the patients, and "to the pain extending from the bottom of the orbit to the occiput, which is always a symptom belonging to deep-seated disturbance in the circulation of the optic apparatus." Rondeau[276] gives an interesting example of severe affection of the eyesight from apparently slight injury to the spine. The patient, seventeen years old, fell on the staircase, striking the neck and shoulders. There was complete loss of sight. Light-perception returned in a month, and four years after he could distinguish large objects in front of him, but vision remained stationary at that point. Albutt informs us that the percentage of visual affections is greater in proportion to the height of the seat of the injury in the spine.

[Footnote 273: _Use of the Ophthalmoscope_, London, 1871.]

[Footnote 274: _Concussion of the Spine_, by John Eric Erichsen, London, 1875.]

[Footnote 275: _Failure of Sight after Railway and Other Injuries of the Spine and Head_, London, 1869.]

[Footnote 276: _Affections oculaires Reflexes_, Paris, 1866.]

TABES DORSALIS.--That affections of the eye are common in this grave malady is admitted by all writers, but as to their frequency and nature at the different stages of the disease, there is wide diversity of opinion: this is probably in part due to the fact that from the chronic nature of the disease, which extends usually over a period of several years, it is rare that the case remains from beginning to end under care of the same observer. The symptoms are of three varieties--viz. firstly, transient paralyses of the external muscles of the eye; secondly, changes in the iris and ciliary body; and, thirdly, affections of the optic nerve. The first-named symptoms are frequent in the early stages of the disease. Sometimes they affect the external muscles supplied by the third pair, and at others the rectus externus. Their transient character and frequency, while admitted by all observers, have as yet received no adequate explanation, it being indeed difficult to see why transient affections of the motor nerves should be so common in a disease which has its seat in the posterior sensory columns of the spinal cord, and which presents such formidable and irreparable lesions. The pupillary symptoms are, as a rule, those of myosis, sometimes mydriasis, and at times the so-called Argyll-Robertson {794} symptom (viz. a moderate myosis, with diminished reaction to light, but prompt response to convergence and accommodation). The last symptom is by no means present in all cases and at all stages of the complaint; but where it exists there is a remarkable resistance to the action of mydriatics. Trousseau was probably the first to call attention to this state of affairs. The writer has repeatedly seen cases where a strong solution of sulphate of atropia failed to produce any more than one-third of the usual dilatation produced by the same amount of the drug. Trousseau and Duchenne have both observed that during attacks of violent pain the pupils of ataxic patients will sometimes undergo temporary dilatation. Atrophy of the optic nerve (either partial or complete) is a frequent, and often an early, symptom of tabes dorsalis, and even may precede by many years the development of spinal symptoms. Foerster relates a case where complete optic atrophy preceded the development of all other symptoms by a period of three years, he having seen a number of other instances when atrophy preceded the other symptoms for a less period. Charcot records a case where the interval was ten years, and states that sooner or later locomotor ataxia develops in the majority of cases of optic atrophy in his wards in the Salpêtrière. Gowers gives two interesting cases, in one of which blindness came on fifteen years before the development of the other symptoms, the interval in the second being twenty years. Buzzard[277] also has recorded an observation where blindness and lightning pains manifested themselves fifteen years before the development of the other ataxic symptoms. If we were to estimate the frequency of optic atrophy as a symptom of early development of tabes dorsalis by the cases seen at ophthalmic hospitals, we should probably much overrate its proportion, inasmuch as those cases in which atrophy is a more marked and early symptom alone resort to such places. Leber found that 13 (26 per cent.) out of 87 cases at his clinic had spinal symptoms, while Gowers gives 20 per cent. as a relation existing between degeneration of the optic nerves and tabes. The latter author thinks that the ratio should really be stated as 15 per cent., because 5 per cent. was due to cases which had been sent to him for examination by his colleagues. Nettleship classifies 76 cases of optic atrophy as follows: 38 as presenting undoubted symptoms of locomotor ataxia; 11 as showing mixed spinal and cerebral symptoms (as in general paralysis of the insane); 9 with other forms of spinal degeneration without brain lesions, these associated with reflex iridoplegia without other symptoms of spinal or cerebral disease; and 15 only in which there was no manifest disorder of other parts of the nervous system. In the earlier stages of degeneration of the optic nerve in tabes dorsalis the discs are usually of a dull reddish-gray tint, and, while they are still capillary superficially, their deeper layers next to the lamina cribrosa have a decidedly diminished blood-circulation, and appear of a marked and more neutral gray color. The surface of the discs often looks more or less fluffy, there being enough haze of the retinal fibres to veil, and at times to hide, the scleral ring. Later, the superficial capillarity disappears and the discs assume a pallid, filled-in aspect, being surrounded by a scleral ring which is everywhere too broad: at this stage the main stems of the retinal arteries and veins exhibit no marked change in calibre, but later on we find them {795} shrinking, and the surface of the disc becomes excavated, the nerve itself often assuming a greenish tint. The earlier stages of such degenerations often exist for a long time, and are demonstrable by the ophthalmoscope before the sight is sufficiently impaired to prevent the patient from executing any ordinary work; this being dependent upon the facts that at first there is only a concentric diminution of the field for form and colors, while central vision remains for a long time unaffected. According to Foerster, this contraction of the field commences at the outer part. In advanced cases there are often irregular sector-like defects. This state of affairs makes it probable that while the number of cases in which total blindness precedes the development of tabetic symptoms is probably rated much too high, from the natural gathering of such cases at ophthalmic hospitals, yet, nevertheless, the frequency of incomplete gray degeneration of the optic nerves in the early stages of the complaint is probably, as a rule, much underrated.

[Footnote 277: _Brain_, ii. 1878, p. 168.]

Foerster has most justly called attention to the remarkable mental cheerfulness of persons laboring under this malady, and states that he has frequently seen cases where the patients would insist that they were improving, while examination of the acuity and of the field of vision showed steady failure of the eyesight. The writer's personal experience has on several occasions substantiated this statement. According to Cyon,[278] tabes presents three varieties: First, tabes dorsalis. This variety commences with paralyses of the eye-muscles and amblyopia. The pupils are not contracted. The amblyopia progresses. Cramp-like disturbances of innervation are always present, with a want of co-ordination of movements and anæsthesia of the upper extremities, while mental disturbances are often demonstrable. Second, tabes cervicalis. Myosis, with intense boring pains in the extremities and impotence, are its chief characteristics. Ataxia is rare, and disturbances of vision develop only late in the course of the disease. Third, a class which he considers the true form of tabes dorsalis, in which there are marked anæsthesia, formication, bladder and rectal symptoms, associated with motor disturbances which often end in paralysis. In such cases there are no eye symptoms except occasional dilatation of the pupil. The same writer has collected 203 cases reported by various authors, and gives the following tables as showing the relative frequency of eye symptoms:

Amblyopia . . . . . . . . . . . . . . . . . . . . . . . . 33 times.
Paralysis of eye-muscles . . . . . . . . . . . . . . . . 30 "
Mydriasis . . . . . . . . . . . . . . . . . . . . . . . . 3 "
Myosis . . . . . . . . . . . . . . . . . . . . . . . . . 9 "
--
75

Amaurosis with affections of eye-muscles . . . . . . . . 16 times.
Amaurosis with mydriasis . . . . . . . . . . . . . . . . 8 "
" " myosis . . . . . . . . . . . . . . . . . . 1 "
Affections of the eye-muscles with mydriasis . . . . . . 4 "
Amaurosis with mydriasis and affection of the eye-muscles 2 "

He remarks[279] that the number of reported cases of mydriasis is probably excessive, and says that dilatation has been improperly noted, as, for instance, where one pupil is normal and the other contracted. As regards the frequency of the Argyll-Robertson symptoms, Vincent[280] found it {796} present in 40 cases out of 51, in which there were 7 cases of amaurosis with immobile pupils, 5 being marked exceptions to the rule. Out of 51 cases of tabes, the same author found myosis in 27. The statements of Vincent (as will be seen) differ materially from those of Cyon. Erb[281] found that in 56 cases, there were only 7 in which the optic nerves were affected (12½ per cent.), while in 17 there were affections of the eye-muscles (30-3/10 per cent.). He considers myosis a frequent symptom, but thinks that the stage at which it develops is not yet determined. The anatomical cause of the want of sensitiveness of the pupils to light, while they retain their movements of convergence and accommodation, has not been well made out. Vincent[282] attributes it to a paralysis of the excito-motor filaments which supply the iris, and which he locates at the upper portion of the spine; while Wernicke thinks it due to degeneration of the filaments which go from the third pair to the optic nerve. Hughlings-Jackson[283] tells us that the pupils which fail to react to light often act but slightly with convergence, and in a note gives two cases of absolutely immobile pupils where the accommodation was nearly normal for the age. In fact, much remains to be accomplished in the study of the innervation of the iris and ciliary muscle in tabes. The proportion of cases in which cycloplegia occurs, and what relation it bears in point of time and frequency to the presence of iridoplegia, are far from being well made out. Jackson also insists that tabes does not necessarily follow in all cases of long-standing optic atrophy. On a basis of 72 cases Gowers says that some formal ophthalmoplegia interna was present in 92 per cent. He groups these cases into three stages: No. 1, where there is loss of knee-jerks, lightning pains, difficulty of standing with toes out and heels together, there being a want of ataxic gait; 2, where there is an ataxic gait, but the patient can still walk by the aid of a stick; 3, where the patient cannot walk without the assistance of another person. In 23 of his cases in the first stage (84 per cent.) symptoms of palsy of some of the intraocular muscles were found; in the second stage, 29 cases (93 per cent.); in the third stage, 18 cases (100 per cent.). Erb has called attention to the fact that reflex dilatation of the pupil from sharp stimulation of the skin of the temple is usually absent where we have the Argyll-Robertson pupil. Gowers admits that this is the rule, but has seen several cases where, although there was no attempt at myosis on exposure to light, yet there was marked dilatation on stimulating the skin.

[Footnote 278: _Tabes Dorsalis_ Berlin, 1866, p. 43.]

[Footnote 279: _Loc. cit._, p. 71.]

[Footnote 280: _Thèse de Paris_, cited by Robin, p. 20.]

[Footnote 281: _Nagel's Jahresbericht der Ophthalmologie_, 1872, p. 150.]

[Footnote 282: _Thèse de Paris_.]

[Footnote 283: _Transactions of the Ophthalmological Society of the United Kingdom_, vol. i. pp. 139-154.]

Unclassified Nerve Diseases.

DIABETES.[283]

[Footnote 283: This affection has been placed here for convenience of classification, and because there is a form of the disease which is of neurotic origin.]

DIABETES MELLITUS.--This disease, which affects so profoundly all tissues of the body, necessarily manifests its influence on the tissues of the eyes. It frequently impairs the nutrition of the vitreous and causes the formation of cataract. The presence of grape-sugar is readily detected in such lenses by chemical examination. Mitchell and other {797} experimenters have produced cataract in frogs by placing them in a solution of sugar. In such instances the lens tissue is said to become transparent when the animal is removed from its sugar bath and placed for a time in water; therefore, it is probable that the cataract has been developed by the simple abstraction of water. Diabetic cataracts are often extracted successfully, and the wound usually heals well; but we occasionally have intraocular hemorrhage during the course of healing. At times the nutrition of the patients is so impaired that a slight accident is dangerous, such as happened in a patient of the writer, where the striking of the hand against an iron bedstead caused gangrene and death. Nettleship[285] has recorded an analogous case, where accidental injury during convalescence caused death from gangrene. At times marked retinitis and hemorrhages with clear media have been encountered; thus, Jaeger in 1855 gave us an admirable picture of such a case, in which there was retinal swelling so great as to hide the outlines of the nerve, it being accompanied by numerous hemorrhages and yellow splotches. In his description of the case he also states that there was a marked central scotoma (a denser inside of a lighter one) in the field, while the periphery of the retina was so little affected that the patient could still decipher large letters (No. 18 of Jaeger's test-types). We might perhaps think that the scotomata are accidental and due to the location of the retinal changes in the given case, but later researches seem to show that we may have them in diabetes without retinal changes, Nettleship and Edmunds describing two such cases. In one of these cases there seems to be some doubt whether it was not a tobacco amblyopia which had been developed in a diabetic subject; but in the other case there was no such complication. The retinal changes which have been recorded in some cases have much resembled those due to albuminuria, but these alterations in the eye-ground have been seen in a number of cases where no albumen in the urine could be obtained.

[Footnote 285: _Transactions of the Ophthalmological Society of the United Kingdom_.]

Diabetes also may, by impairing the nutrition, diminish the power of accommodation in the young and cause a rapid increase of presbyopia in old persons (Graefe, Nagel, Foerster). Horner[286] proved that a hypermetropia of 1/14 in a patient of fifty-five years of age rapidly diminished to H. = 1/48, and the amount of presbyopia remained unaltered, while the general health had improved and the quantity of sugar had diminished. He attributes this rapid increase and subsequent diminution of the hypermetropia to a change in the amount of the fluid contents of the eye. Were this reporter any less careful an observer, one might be inclined to suspect swelling of the lens; but he specially mentions that there was no trace of cataract formation.

[Footnote 286: _Klin. Monatsbl. f. Augenheilkunde_, 1873, p. 490.]

EPILEPSY.