Читать книгу Tics and Their Treatment - Feindel Eugène - Страница 9

We have seen how various purposive, co-ordinated movements may, by dint of education and voluntary repetition, become automatic and be automatically repeated should occasion arise. Imagine some such act recurring involuntarily without any apparent reason and for no apparent object; what does such an anomaly signify?

Take, for instance, the case of a young girl who inclines her head on her shoulder to relieve the pain of a dental abscess. The act is called forth by a real exciting cause; the muscular response is voluntary, deliberate, undeniably cortical in origin: the patient wills to appease the pain by pressing and warming her cheek. Should the abscess persist, the movement will be repeated less and less voluntarily, more and more automatically; but as the why and the wherefore still remain, there is nothing pathological about it.

With the healing of the abscess, however, and the consequent relief of the pain, the girl still inclines her head on her shoulder from time to time, albeit cause and purpose have ceased to operate. Her primarily volitional, co-ordinate, systematic, motor reaction is now automatic, inopportune, and meaningless: it is a tic.

Charcot11 has given us an excellent description of the process:

However complex and bizarre may appear the convulsive phenomena known as tics, they are not always as irregular, inco-ordinate, and contradictory as superficial examination might lead one to believe. On the contrary, they are, as a general rule, systematised; in a given case they recur always in an identical manner, reproducing, and simultaneously exaggerating, complex, automatic, purposive movements which are essentially physiological; they are in a sense the caricatures of ordinary acts and gestures. The tic is not in itself absurd; it appears so only because it occurs inappositely, without obvious motive. Source of irritation is absent, yet the patient scratches himself; he blinks, but no foreign body is to be detected in his eye.

Mere repetition does not, cannot, evolve a tic in every case. Not all who would may tic; psychical predisposition in the shape of volitional enfeeblement is a sine qua non.

Of the rôle played by mental insufficiency in the genesis of tic we shall have much to say later. The point we are desirous of emphasising now is that the first manifestations of tic have their origin in, and are dependent on, cortical activity, at least in a majority of cases.

Notwithstanding painstaking investigation, determination of the initial cause may no doubt be difficult in some instances, owing to the patient's ignorance or forgetfulness; for that matter, the observer may not know how to set about his task. Prolonged interrogation, however, and due consideration of the patient's environment, will generally enable him to reconstruct the pathogeny of the condition.

It has been our practice for some years now to examine with especial care into the mode of onset, and to scrutinise the reasons for the particular localisation, of any given tic; and we have been able, in practically every case, to rediscover the exciting cause, and consequently to explain the form taken by the tic in its earliest manifestations as a voluntary response to the stimulus. Time may have distorted the original movement, but a little patient analysis will facilitate its recognition even in the caricature made of it by the tic.

A few concrete instances will help us better to understand the nature of this psycho-physiological mechanism.

An individual is wearing a collar too small for him, and its frayed edge chafes his skin; the neck is at once abruptly inclined away from the irritating point – a simple spinal reflex movement of defence. Now that he is warned by the sensation of pain, he wishes to avoid it, which he does by bending his head to the opposite side. The act is similar to the preceding, but of a totally different nature; it is voluntary, not involuntary; cortical, not bulbo-spinal.

Next day the collar is replaced by another of ampler proportions. There is no further irritation of the skin, and accordingly no occasion for deviation of the head. Memory of the disagreeable sensation may perhaps incite him to verify the disappearance of the irritation by a few movements of the head, and in the normal individual the matter ends there. Even should the idea of repeating the gesture, now become meaningless, occur to him, he banishes it by an effort of the will.

With the candidate for tic things pass in quite a different fashion. Uncalled for though it be, he performs the brusque movement of yesterday perhaps with a view to satisfying himself that the pain is non-existent, but he is not thus satisfied. He does not limit his experiments to one or two attempts. He repeats it frequently and complacently. The original source of irritation is gone; the movement intended at first to relieve it persists. Soon the whole trouble is forgotten, but the reiterated gesture becomes habitual and automatic; it may have been rational yesterday, but to-day it is superfluous, if not actually prejudicial; it is a tic. In its evolution the cortex has had a part, and the very untimeliness of this cortical intervention indicates a certain disorder of psychical function.

Or again: a speck gets under my eyelid, and I wink – a spasmodic act independent of the cortex. The speck is removed, but the conjunctiva remains a little tender, and I wink again – still only a spasm. All trace of irritation vanishes, yet the blinking persists: it is degenerating into a tic.

Wherein consists the rôle played by the cortex in the production of such phenomena? It intervenes to order the repetition of the gesture provoked involuntarily, in the first instance, by peripheral excitation; and though one may not always be able later to discover evidence of this, one must at the least recognise the fact that the mere inopportune persistence of the movement bears witness to psychical imperfection.

It has been remarked by Guinon that patients suffering from tics of blinking attribute them to the presence of foreign bodies; he declares, however, that "if they bear a superficial resemblance to simple tic, they differ widely in essential characters and from the point of view of prognosis. They are really involuntary movements of reflex origin, occasioned by abnormal sensations, usually of pain." He cites as a typical instance the "tic douloureux" of the face.

The description is strictly accurate provided the pain continue; such acts are not tics, they are spasms. On the other hand, the perpetuation of the movement in the absence of all exciting cause and pain constitutes it a tic. In this way a spasm may be the forerunner of a tic, and in many cases no doubt a purely spasmodic motor reaction may determine the form and localisation which the latter will adopt; but, as we have said, its first manifestation is usually a voluntary act of definite causation, and directed to the accomplishment of a definite object.

The candidate for tic is mentally unstable. Indifferent perhaps to acute suffering, he may become entirely preoccupied by some trifling sensation of pain or by some source of petty annoyance, to rid himself of which he will resort to all sorts of tricks and assume all sorts of odd attitudes – tic germs quick to develop in suitable soil.

In many motor reactions of the class we are now considering the main object is the avoidance of some abnormal sensation, suppression of which, however, brings no relief to the patient's mind. He dreads its reappearance; he must assure himself of its absence. He taxes his ingenuity in the attempt to rediscover the sensation, and multiplies his gestures and attitudes until once again he experiences it. The satisfaction he felt originally in shunning the pain or the discomfort is paralleled by the satisfaction he now knows in its rediscovery. In each instance the motor phenomena are voluntary and co-ordinated, but their excessive repetition betrays unstable mental equilibrium.

Instructive examples of this pathogenic process are furnished by the history of O., and by the case of a young patient J., from which we extract the following:

In 1896, during the holidays, a tic, secondary to some slight nasal ulceration, made its appearance. The child learned the trick of wrinkling its nose and of puckering its upper lip, sometimes attempting by various facial grimaces to lessen the irritation due to the little nasal sore, sometimes, on the contrary, finding delight in deliberately seeking the unusual sensation. The sniffing soon became involuntary, and for the next two months, long after the ulceration was healed, this nasal tic continued.

Then another cause came into operation, occasioning a new gesture and entailing a new tic. Cracking of the labial mucous membrane during winter led to incessant licking and nibbling at the roughened surface. With the first excoriation the patient proceeded to moisten his lips with his tongue, whence fresh cracks, followed by the renewal of nibbling and licking movements.

In March, 1899, after a severe attack of influenza accompanied by fever and pains in the joints, he began to complain of stiffness and a sort of cracking in the neck, disagreeable rather than painful. To avoid this, or to reproduce it – as one sometimes amuses oneself by "cracking one's joints" – he quickly learned to make all sorts of bizarre head movements, and so a tic of the neck started which lasted several months.

Noir has directed attention to a tic of frequent occurrence among amaurotic idiots, consisting in rapid to-and-fro movements of the finger before the eyes. The explanation seems to be that their blindness is not absolute enough to prevent some faint appreciation of light by retinal stimulation, and the effect of the luminous impression is enhanced by the alternation of light and shade sensations produced by the waving of the fingers in front of the eyes. The tic is neither more nor less than a search after this effect.

Another case in point is reported by Dubois12:

The patient is a young woman twenty years old who has acquired the habit of beating her right elbow against her chest fifteen or twenty times a minute, until it happens to impinge with rather greater violence on a whalebone in her corset; this is accompanied by a slight guttural cry. It would appear the sole satisfaction in her tic is in the attainment of this object, since it is succeeded by temporary cessation of the movements. Their constant repetition has caused an insignificant erosion of the skin over a limited area on the elbow, and it is only when this particular spot is touched that the ejaculation is uttered and the tic arrested. If the elbow be at rest, the head is inclined from left to right several times a minute.

Evidently, then, in the subjects of tic the impulse to seek a sensation is of very common occurrence, as is also the impulse to repeat to excess a functional act. It is precisely this exaggerated and inopportune multiplication of movement that is pathological.

The mother of one of Noir's patients was always tempted to repeat any simple purposive movement that she had made a moment before, even though the reason for the act no longer existed.

The imperiousness of these impulses, and the peculiar relief attendant on submission to them, accentuate the closeness of the resemblance between tic and obsession, to which reference will be made later; but it is necessary at this early stage to indicate the bearing of these psychical phenomena on the pathogeny and diagnosis of tic.

Many of the conditions with which we are dealing are characterised in addition by an emotional element. Dupré13 believes an emotional shook is the exciting cause of tic, as it sometimes is of obsessions.

Apropos of this view, we may quote again from the history of the young patient J.:

During his holidays he improved sufficiently to enable him to resume his classes, but another attack of influenza in the beginning of 1900 was the occasion of a relapse. He began to complain of overpowering fatigue; became depressed and morbidly anxious about his future; had attacks of hysterical sobbing; suffered great mental anguish, accompanied by flushing and profuse perspiration; in short, he fell into a veritable state of mal obsédant.

At the same time, the slightest pain or annoyance was a pretext for his tics to exhibit themselves with redoubled vigour. Even the mere idea of his tics, the fear of them, incited him further in the same direction. He seems then to have set himself to invent new movements, and forgetting forthwith that he himself was their creator, became alarmed at them as sure signs of the aggravation of his disease.

Analogous details will be found in all cases which have been studied as well from the mental as from the physical side. For our part, we consider a tic cannot be a tic unless it be associated with a certain degree of mental instability and imperfection, indubitable evidence of which is furnished by a psychical abnormality of constant occurrence in this malady – viz. anomalies of volition.