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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. Magnan³⁹ 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 place⁴⁰ 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 Debrou⁴¹ 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.

Féré⁴³ 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 Buss⁴⁵ 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 recently⁴⁷ 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 Patella⁴⁸ 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.

CHAPTER VII
STUDY OF THE MOTOR REACTION

THE general characters of the motor reaction constituting the objective manifestation of tic form the subject of previous analysis in the chapter on pathological physiology. It is our present intention to approach them from the semiological point of view.

To give a description of the motor disturbance of universal applicability is evidently to attempt the impossible. The modifications of functional acts are legion, and in the case of tic anomalies of muscular contraction vary not merely with the individual, but in the individual. Each tics after his own fashion; and no two tics are ever exactly interchangeable. As Trousseau was wont to say, "the disease in a sense forms part of the constitution of the person affected."

THE TYPE OF MOTOR REACTION – CLONIC TIC AND TONIC TIC

The motor reaction may be either clonic or tonic in type. Clonic tics are distinguished by more or less abrupt contractions, separated by longer or shorter intervals of relaxation or repose. The duration of a clonic tic convulsion may be exceedingly brief, though perhaps not so brief as the instantaneous "electric" twitches of a spasm, which have the extreme rapidity of pure reflex phenomena. Exception ought to be made for the face, no doubt, seeing that the suddenness of the movements in facial tic is precisely what complicates the diagnosis between it and facial spasm, as we shall see. In the limbs, the variations appear to stand in close relation to the nature of the primary factor, the mental condition of the patient, and the mode of reaction peculiar to him. The quickness with which the reaction occurs increases in proportion to the length of time the tic has existed, although once it has become habitual, any further change is rather in the direction of additional complexity.

Sometimes a relative deliberateness of execution raises suspicions as to the accuracy of the diagnosis. In the case of a child with several tics, one affecting the mouth in particular, Guinon was struck by the slowness of the muscular contractions.

To begin with (he says), the mouth was opened gradually, but as soon at the limit of separation of the maxillæ was reached, it was immediately closed, without remaining even for a moment in the extended position, as one would have expected had there been a tonic contraction of the infrahyoid muscles.

Cases of this kind, however, are not really instances of the tonic variety.

One of us has had the opportunity of observing a young woman afflicted with a curious combination of motor disorders, akin no less to the clonic form of tic than to the gesticulations of chorea and the undulatory movements of athetosis. Their resemblance to the clinical type described by Brissaud under the name of variable chorea is noteworthy, a distinguishing feature, however, being the sluggishness of the muscular contractions, which may well be a reflex of the patient's mental inertness.

Mademoiselle R., a young woman twenty-six years old, is a small and delicate creature with slender limbs and tapering fingers. She is extremely myopic, but her general health is excellent, and there is nothing to suggest that she is suffering from organic disease of the nervous system. Apart from the fact that her parents are rather "nervous," the family history is negative.

Since the age of twelve she has been subject to various tics of the face and head. She wrinkles her forehead and moves her scalp to and fro, and sometimes she turns her head slowly and steadily towards the left side, raising her eyes up and to the left at the same moment. Head and eyes forthwith resume their normal position. The deliberateness of the act is altogether exceptional. If, however, she happens to be wearing her hat – which is remarkable for its size, weight, and unwieldiness – the gesture is repeated in a quick and jerky manner. Any diversion, such as reading, knitting, listening to a conversation, especially if she feels she is not being noticed, will augment the intensity of the movements, which the thought of being observed, or the awakening of her interest, or rest in bed, or sleep, has the effect of abbreviating or checking.

Our earliest step was to confiscate the offending hat, and this had the instantaneous result of diminishing the violence and frequency of the tic, which the subsequent practice of appropriate exercises entirely dispelled.

If now we direct our attention to the psychical aspect of the case, we are struck with the goodness, devotion, and disinterestedness of our patient. Her one concern is for the welfare of others, and she is indifferent to the pleasures of literature, art, games, or even work. All that is required of her she performs with docility, but never with animation. The extent of her passiveness is seen in her childlike acceptance of her parents' wishes. Her temperament is neither gay nor sad, but merely dull. Indolence and maladroitness predominate in all her actions, and reveal themselves in the curious awkwardness and nonchalance that characterise the execution of even the simplest movement. She is essentially of a very unstable nature, but its torpidity is no less obvious than its instability. If there is no abruptness in her acts, it is equally true that she is never still. She cannot maintain any given attitude; she cannot fix her gaze on any particular object. Her restlessness is such that her position is changed from moment to moment, however slowly and imperceptibly. Her eyes are only half opened; as she speaks, her lips are scarcely seen to move.

It has been a laborious and protracted task to teach her to sit motionless with her hands in front of her, and no less unremitting effort has been required to make her open her mouth properly, or turn her head naturally from side to side.

In some ways the endless movements of her hands and fingers – she never ceases playing with her dress or her gloves or her handkerchief – are vaguely reminiscent of those of athetosis, and on the left side especially, if they become a little brisker, there is slight hyperextension of the phalanges. She reads aloud in a low, colourless, monotonous tone of voice, without punctuation or accent, articulating the syllables defectively and slurring the ends of the words. At the finish of each paragraph comes a halt, as if from fatigue, and on command a fresh start is made with the same careless indifference. As for the lower extremities, the tale is identical. Mademoiselle R. cannot stand upright. She rests on either one leg or the other. Her left foot is never flat on the ground, but sometimes on the inner border, sometimes on the outer. The faulty attitude is readily enough corrected, though she declares she is ignorant of it. It is a sort of half clonic, half tonic, tic of the foot, whose slowness is on a par with that of all her other acts.

It is because clonic tics are so easily recognised that they are the most familiar, but we must not ignore another variety – viz. the tonic tics, corresponding to the tonic form of convulsion.

Tonic tic is of common occurrence in cases of mental torticollis. In that disease rotation of the head may be sustained for a considerable length of time without interruption, showing the permanent nature of the muscular contraction. Strictly speaking, we are concerned not with a sudden gesture, but with an attitude. Abundant evidence is forthcoming to substantiate its mental origin, and it may therefore be described as an attitude tic. Among other instances of tonic tics may be specified the affection of the masseters known as mental trismus (Raymond and Janet), or that continuous contraction of the orbicularis which keeps the eye half closed, though it may momentarily disappear under the influence of the will – a tonic blinking tic. O. and young J. have already supplied examples of attitude tics, and reference may further be made to another of our patients⁴⁹:

Sometimes the mouth is drawn directly and completely to the left, more usually to the right; at other times simultaneous contraction of the upper and lower lips takes place, constituting a sufficiently faithful reproduction of the grimace made by a child in the attempt to refrain from crying; at other times still, imperfect closure of the lids and upward deviation of the eyes bear a resemblance to children's imitation of a blind man. Displacement of the mouth to the right is the movement of longest duration, and while it persists the patient is capable of stuttering speech, without relaxing her lips. The other tics last but a few seconds, while all vanish if she laughs or opens her mouth wide to exhibit her tongue. They follow each other at irregular intervals, and during the moments of rest the face resumes its normal expression.

Cruchet, as has been already remarked, has criticised the use of the term attitude tic, on the ground that the adoption of an attitude, however vicious it be, need not be the outcome of a convulsion. Doubtless; but it is no less true that a tonic convulsion may "take shape" —e. g. the arc de cercle of hysteria, the phenomena of catatonia and catalepsy, etc. Of course if the word tic is to be synonymous with intermittent twitching, then it is inapplicable in this class of case; but if our connotation of the term be accepted, we must find an expression that will serve to differentiate between tonic and clonic varieties. We are not aware of any particular advantage in describing the condition as a permanent contraction, for the obvious result of a permanent contraction, whether it be clenching of the jaws, occlusion of the eyelids, or rotation of the head, is the production of an attitude, a "position in which the body is kept" (Littré). No other designation could therefore be more appropriate than attitude tic, or could indeed be imagined, seeing that Cruchet himself ranges mental torticollis among the tics, and describes it as "an attitude of defence and of repose."

It may sometimes happen that the manifestations of stereotyped acts consist in the assumption of attitudes, but in spite of their affinity to the tics we deem it preferable to reserve the term "stereotyped attitude" or "akinetic stereotyped act" for cases where the motor reaction is clothed in the form of a normal movement. As it is inaccurate to describe as a tic a repeated gesture whose execution is normal in degree and in rapidity, so the mere immobility of a limb, or the prolonged contraction of a muscle, ought not to be called an attitude tic if the muscular effort does not differ from that which a healthy person would make to preserve the same position. In such circumstances we say that it is a stereotyped gesture or attitude. For the diagnosis of tic it is insufficient to establish the existence of a transient or permanent muscular contraction, and to note the inopportuneness of the movement; the contraction must be abnormal in itself, its abruptness unwonted and its intensity excessive – in short, it must be a convulsion; and finally, its repetition must be continued and exaggerated.

We have felt that some such explanation as the foregoing is required to justify our use of the term tonic or attitude tic, to whose close intimacy and association with the better-known type pathogeny and clinical observation alike bear witness. In any case such terms as myotonus or myoclonus are too comprehensive, in view of our present-day knowledge, to specify the particular motor affection with which we are concerned.