Tics and Their Treatment :: CHAPTER VI PATHOLOGICAL ANATOMY

CHAPTER VI PATHOLOGICAL ANATOMY

OUR ignorance of the pathological anatomy of tic is profound. Hitherto all the cases labelled tic in which a post-mortem examination has been made have in reality been spasmodic affections differing essentially from the tics as we understand them, according to the ideas of Trousseau, Charcot, and Brissaud. As far as we are aware, not a single sectio of a genuine case of tic is on record where a lesion, of whatever nature or whatever site it be, has been discovered to which the tic might be attributed. Either an autopsy is not obtained, or if it is, no special abnormality is remarked, or else the diagnosis has been erroneous and the changes described have not been those of tic.

It would be premature, of course, to conclude that tic is a disease sine materia. The affirmation is quite unwarranted. As is the case with numbers of neuroses and psychoses, we must for the present rest satisfied to observe symptoms; the mystery of their morbid anatomy will remain unsolved until our methods of investigation attain perfection. Magnan[39] says of "superior degenerates" that clinical observation reveals functional disorders so distinct and so invariable that it is impossible they should not be the outcome of some pathological modification of the organism. It is true he declares in another place[40] that the mentally unstable have all a family likeness, consisting not in identity of well-defined anatomical lesions, but in similarity of functional derangements. As it is, from the motor point of view tic is a functional act, and the governing centre is a functional centre that has become hypertrophied, so to speak, by being educated to excess. This physiological centre must not be confused with the "centre" of current anatomical terminology; it does not exercise an exclusive control over a particular territory—several such may co-exist in a single anatomical area.

Our lack of knowledge concerning the precise localisation of these functional centres is paralleled by our ignorance as to the manner of their involvement.

Noir has prudently observed that the manifestation of co-ordinated tics in cases of widespread cerebral disease, and the frequent occurrence of the most extensive and complex varieties in patients who have suffered from meningeal affections, suggest their cerebral origin. On these points, however, anatomo-pathological information is to seek, and for that matter the direct dependence of such an habitual movement as a co-ordinated tic upon one lesion is scarcely within the bounds of probability. Tic pertains to a psychical rather than to a motor sphere, and is to be regarded as a disease of the will.

With this statement, and with the expression of our hope that subsequent work will aid in the elucidation of the question, we shall close the chapter of the tic's pathological anatomy. It may not prove superfluous, however, to indicate why and how the facts gleaned from pathology and supposed to be in harmony with the clinical picture of tic should be allocated to other morbid entities.

In several cases considered to be tics of the face, cortical lesions have been discovered at the posterior end of the second frontal convolution, in the centre for voluntary and co-ordinated movements of the contra-lateral facial muscles. It has become classical to cite an example described as long ago as 1864 by Debrou[41] under the title "painless facial tic," but a glance at the observation suffices at once to negative its classification as a tic, and to justify the diagnosis of a spasm of a quite peculiar sort.

On February 26, 1862, a porter, aged forty-nine, was suddenly seized with an "attack of the nerves," and at its close lost his speech. When examined at the hospital two days later, he was found to have full use of his limbs, understood perfectly all that was said to him, and evinced great impatience at being unable to respond except in writing or by gesture. He made signs to indicate that his head was paining him, and that he had difficulty in swallowing. In addition, abrupt, forcible, and rapid movements of the facial muscles on the right side were taking place; the angle of the mouth and the outer angle of the palpebral aperture were being dragged on; the external ear was elevated, or moving to and fro; the platysma was twitching visibly and the hyoid bone so acted on as to pull up the larynx spasmodically. The exhibition was an exact replica of the effect produced in animals by intracranial galvanisation of the facial nerve. Moments of absolute repose alternated with periods of spasm of a few seconds' duration, which addressing or handling the patient seemed to aggravate. There was synchronous spasm in the masseter muscles, resulting in elevation of the inferior maxilla. No other region of the body was affected.

On the night of March 2 the attacks of spasm and of pain increased in intensity and frequency, without any other change in their nature. The patient's mind remained unclouded, and as he was still deprived of the faculty of speech, he again indicated in writing the severity of his sufferings. About eleven o'clock at night the situation became more distressing; he began to be profoundly agitated, then passed into a more or less maniacal state, in which his limbs were involved in powerful muscular spasms, his eyes rolled in their sockets, and his respiration commenced to be stertorous, while the violence of his struggles necessitated the intervention of two assistants to control him. An hour or two later, during one of these attacks the end came.

At the autopsy, under the arachnoid and spreading over the left hemisphere at the junction of its anterior and middle thirds, was a large blood-clot, dark, coagulated, and free in the cerebral substance, which it had penetrated for a depth of about one centimetre. It appeared to be of about four or six days' formation, and probably dated from the incipient "attack of the nerves." Painstaking scrutiny of the cerebellum and cranial nerves failed to reveal any further pathological condition.

To tell the truth, we are not averse to wagering that to-day the opinion of the surgeon would be invited on a similar case, where the motor reactions of the so-called tic are manifestly based on a Jacksonian type.

In a case recorded by Chipault and A. Chipault,[42] and characterised by brief epileptiform attacks involving the left side of the face, cerebral exploration proved ineffectual, but at the post-mortem a subcortical glioma of the size of a cherry was discovered underneath the posterior end of the second frontal convolution. Is a case of cerebral tumour to be labelled tic?

It is quite exceptional, in fact, for lesions of the cortical facial centres to give rise to muscular movements suggesting facial tic. Take another instance:

An interesting case (says Brissaud), and one that is everywhere quoted, is reported by Schultz, in which an aneurism of the vertebral artery, at the point where the basilar arises, compressed the trunk of the left facial nerve, and occasioned a "tic" of ten years' duration. As a matter of fact, one could not have a better example of spasm pure and simple.

FÉrÉ[43] cites the following incident in support of the contention that encephalic trauma may engender a tic:

A man in falling on his head sustained an injury to the cranial vault over the posterior section of the left parietal bone, at a spot exactly corresponding to the posterior part of the angular gyrus, and immediately became afflicted with a convulsive tic of the zygomatics and orbicularis palpebrarum on the right. Conformably to Ferrier's experimental localisation of the motor centre for the eye muscles and lids in the angular gyrus, irritation of this centre by the cranial injury was the diagnosis made.

The proffered interpretation of the motor phenomena by cortical excitation is entirely justifiable, but no convulsion consecutive to traumatism can ever pass muster as a tic.

A no less frequently quoted experiment of Gilbert, Cadiot, and Roger,[44] supposed to confirm certain results obtained by Nothnagel, is now a standard case in the history of tic hypotheses. The animal in question was a dog affected with spasmodic twitches of the ear, which the successive removal of cortical facial centre, internal capsule, corpora striata, and cerebellum, signally failed to alleviate, and which disappeared only with the destruction of the corresponding nucleus in the pons. Their inability to find any anatomical change determined the experimenters in favour of the view that the trouble was functional, and they described it as a tic.

It would be foolhardy to deny the existence of a lesion on the ground that it was not discovered. Negative findings of this sort are valueless. The sole conclusion to draw from the incident is the all-important rÔle played by the bulbar centres in the production of convulsive movements, which are in such circumstances, of course, nought else than spasms.

Compression of cranial nerves by tumours or aneurisms of the base has been the cause of symptoms imagined to be identical with those of tic. The case of intracranial neoplasm mentioned by Oppenheim, in which irritation of the upper branch of the trigeminal was accompanied by homolateral facial contraction, is wholly comparable to the so-called "tic douloureux."

No less positive is our refusal to accept as tics spasmodic contractions in association with or subsequent to facial palsy or contracture of peripheral or central origin. They are spasms, not tics. Cruchet, for instance, describes indifferently as labial tic or intermittent labial hemispasm clonic elevation or depression of the oral aperture developing in central facial paralysis, especially in children. As example he refers to the case of a child in whom an ictus at the age of three years was followed by a typical spastic hemiplegia on the left side, with athetoido-choreic movements chiefly in the arm.

At first the left side of the face was flaccid and deviated in the other direction, but at the time of examination it presented no unusual feature beyond a continual twitching, a real convulsive tic, of the upper lip.

Now, whatever a facial convulsion of apoplectic origin, secondary to facial palsy and accompanied with spastic hemiplegia and athetosis, may be, it is at all events no tic.

Take one more case, given by Buss[45] as "convulsive tic of the left side of the face."

The patient was an atheromatous subject, with cardiac hypertrophy, bronchitis, and emphysema. When he first came under observation at the hospital, his eyelids, cheek, and buccal commissure were the seat of painless clonic contractions, which a month later were complicated by giddiness, vomiting, inability to stand or walk, lancinating pain over the right side of the face, weakness of the right limbs, and left facial paresis, and had become fugitive and insignificant. Loss of consciousness was followed by flaccidity of all four extremities, hyperpyrexia, and death. The section showed a hÆmorrhage of the dimensions of a pigeon's egg which had destroyed the left half of the pons, and an atheromatous dilatation of the left posterior cerebellar artery, impinging at one spot on the seventh and eighth nerves of the same side. Microscopical examination of their trunks and of the facial area in the pons disclosed no abnormality.

The pathological anatomy of this case indicates its nature unmistakably, and its symptomatology and evolution, moreover, do not bear the remotest resemblance to those of tic.

In the opinion of Debrou,[46] convulsive tic is a functional derangement of a motor nerve, analogous to the neuralgia of a sensory one. To strengthen his argument he relied on such cases as those of Romberg, Schultz, Rosenthal, Oppolzer, where disease of neighbouring structures (enlarged glands, otitis media, caries of the temporal bone, etc.) was the agent in the production of muscular twitches in the domain of the facial. In our view, however, they are simply spasms provoked by irritation on the centrifugal path of a reflex bulbar arc.

The slight contractions occasionally seen both on the paralysed and on the non-paralysed side in the secondary contracture stage of facial palsy—a condition noted by Duchenne of Boulogne, Hitzig, and others, and distinct from fibrillary twitching—are nothing more than spasms, and the same obtains where the palsy is consecutive to affections of the ear.

Chipault and le Fur recently[47] communicated to the Academy of Medicine a case of intermittent attacks of acute pain in the right hypochondriac region, associated with violent contractions of the muscles of the right abdominal wall, which they described as a tic comparable to tic douloureux of the face. It was seen at the subsequent operation that the eighth, ninth, and tenth posterior spinal roots on the right side were surrounded in their passage through the meninges by a patch of matted and cicatricial arachnoiditis, dissection of which was instrumental in effecting immediate relief.

One could not desire a more typical example of reflex spasm, the area of irritation in this case being situated at a point on the centripetal arc close to the medullary centre.

We may be allowed to quote a last case from Cruchet:

A little phthisical girl, four and a half years old, began to complain of headache, and in the course of the next day became delirious. Three days later the delirium gave place to generalised convulsive seizures affecting chiefly the arms, and more pronounced on the left side. Simultaneously a tic of the right side of the face was observed, distinguished by raising of the upper lip and closure of the palpebral aperture. Sleep brought no modification in its train. Up to this stage a very feeble degree of contracture of the jaw muscles had been noted, but this speedily became accentuated to such an extent that nasal feeding had to be adopted. Some hours previous to the child's death the tic disappeared, only occasional slight convulsive twitches of the right arm remaining. Consciousness was maintained to the last minute.

At the autopsy the characteristic appearances of tuberculous meningitis were found: the base of the brain at the anterior perforated spot and origin of the sylvian artery was covered with gelatinous purulent patches, the colour of prune juice, which extended backwards to the pons; one in particular had enveloped the basilar trunk and sent out a prolongation on the right side, which surrounded the sixth, seventh, and eighth nerves at their point of emergence.

For our part, we cannot apply the word tic to the convulsive phenomena of tuberculous meningitis. If localised spasms occurring in the course of a grave illness, associated with fever, headache, and delirium, with contractures and generalised convulsions, and if the spasmodic manifestations of rapidly fatal pyrexias, are all to be denominated tics, then the term has no longer any significance, and it would be wiser to give it at once its quietus.

We are well enough aware that Cruchet believes there is a "convulsive tic symptom"; in other words, certain symptoms in such and such a disease appear in the guise of convulsive tic, "a movement or combination of movements representing in a clonic fashion a physiological act." Nevertheless, we are not convinced that the convulsive movements of Cruchet's patients exhibit the sequence of "regulated physiological acts."

He further draws an analogy between the foregoing case and the partial convulsions of toxÆmias, cerebral tumours, etc., "transient convulsions supervening in the course of acute or chronic affections, and readily recognisable." In exceptional circumstances they may "assume the form of convulsive tic." In strict truth the form may be the same, but examination of the patient will soon demonstrate that the two are alike merely in appearance, and compel the reconsideration of an immature diagnosis.

Our position is that tic is more than a symptom—it is a symptom-complex. Cruchet's definition of convulsive tic just quoted is by itself insufficient; the additional and indispensable factor is the characteristic mental defect, of which so illuminating an exposition was given by Charcot.

Finally, the knowledge derived from the pathological investigation of myoclonus and polyclonus does not of necessity throw light on the morbid anatomy of tic.

In the case of an epileptic who suffered from myoclonus in his last years, ischÆmic degenerations were found by Rossi and Gonzales disseminated throughout the brain, especially in the rolandic area, but any inference to hold good for the tics would be premature.

The term polyclonus has been employed by Murri to designate a succession of clonic contractions of the limbs, due to the existence of punctiform hÆmorrhages or areas of softening scattered throughout the rolandic cortex. The character of the motor reaction in these cases, however, bears no resemblance either to tic or to chorea, although the fact of the relation between diffuse cortical lesions and convulsive movements is calculated to enhance the difficulties of diagnosis.

Vincenzo Patella[48] has recently called attention to a case of polyclonus in which the disappearance of the symptoms during sleep suggested their purely functional origin, but histological examination of the rolandic grey matter at a subsequent period revealed the presence of numerous foci of degeneration. We are as yet, however, far from grasping the real meaning of such symptoms, which, moreover, from the clinical standpoint, cannot always be assimilated to those of the tics. Conclusive anatomical information is therefore still being awaited.

The functional nature of the movements we have had under discussion is unfortunately an obstacle in the way of our early knowledge of their pathology. As long as we remain ignorant of the actual cause of the neuroses and psychoses, so long will the pathological anatomy of tic continue a sealed book. All that has been written on this topic hitherto really concerns spasm and other convulsive affections secondary to irritation of nerve centres or conductors. If we may venture to express an opinion, it is that we should not be surprised if post-mortem examination rest constantly negative. As a matter of fact, we do not favour the view that the phenomena depend on an acquired lesion; rather are we inclined to believe that they represent some congenital anomaly, some arrest or defect in the development of cortical association paths or subcortical anastomoses, minute teratological malformations that our medical knowledge is still unhappily powerless to appreciate.

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