Part 3 (1/2)

Its etymology has not much information to furnish. The probability is that the word was originally onomatopic, and conveyed the idea of repet.i.tion, as in tick-tack. _Zucken_, _ziehen_, _zugen_, _tucken_, _ticken_, _tick_, in the dialects of German, _tug_, _tick_, in English, _ticchio_ in Italian, _tico_ in Spanish, are all derivatives of the same root. It matters little, in fact, since the term is in general use and acceptable for its shortness and convenience. In popular language every one knows what is meant by a tic: it is a meaningless movement of face or limbs, ”an habitual and unpleasant gesture,” as the Encyclopaedias used to say. But the definition lacks precision.

A glance at the history of the word will reveal through what vicissitudes it has pa.s.sed. We need but remind the reader of its exhaustive treatment in the Dictionaries, and refer him for an elaborate bibliography to a recent work by R. Cruchet,[1] to which we shall have occasion to return.

There is no justification for regarding the risus _sardonicus_ of the ancients as a tic. All that we can say is that the phrase apparently stood for a complex of facial ”nervous movements,” whether accompanied by pains and paralyses or not. Nor can the _rictus caninus_ or the _tortura oris_ have been other than spasms or oontractures of the face.

Previous to its introduction as a technical term, the word _tique_, _ticq_, _tic_, was in current use in France, and applied in the first place to animals. In 1655 Jean Jourdin described the _tique_ of horses.

In eighteenth-century literature tic appears in the sense of a ”recurring, distasteful act”--as expressed by the _Encyclopaedia_--especially in individuals revealing certain eccentricities of mind or character. This old-time opinion is worth remembering, particularly in view of latter-day theories.

Once adopted by the eighteenth-century physicians, the application of the word was extended in various directions. Andre (1756) was the first to mention _tic douloureux_ of the face, an affection excluded to-day by common consent from the category of true tics. Simple, painless convulsive tic, spreading from face to arms, and to the body as a whole, was differentiated by Pujol in 1785-7. During the earlier half of the nineteenth century no solid progress was achieved by the work of Graves, Francois (of Louvain), Romberg, Niemeyer, Valleix, or Axenfeld. It is to the clinical genius of Trousseau that we owe the rediscovery of tic, the careful observation of its objective manifestations, and the recognition of accompanying mental peculiarities.

In spite of the fact that he considered it a sort of incomplete ch.o.r.ea, and cla.s.sed it[2] nosologically with saltatory and rotatory ch.o.r.eas and with occupation neuroses, Trousseau's original account remains a model of clinical accuracy:

Non-dolorous tic consists of abrupt momentary muscular contractions more or less limited as a general rule, involving preferably the face, but affecting also neck, trunk, and limbs. Their exhibition is a matter of everyday experience. In one case it may be a blinking of the eyelids, a spasmodic twitch of cheek, nose, or lip; in another, it is a toss of the head, a sudden, transient, yet ever-recurring contortion of the neck; in a third, it is a shrug of the shoulder, a convulsive movement of diaphragm or abdominal muscles,--in fine, the term embodies an infinite variety of bizarre actions that defy a.n.a.lysis.

These tics are not infrequently a.s.sociated with a highly characteristic cry or e.j.a.c.u.l.a.t.i.o.n--a sort of laryngeal or diaphragmatic ch.o.r.ea--which may of itself const.i.tute the condition; or there may be a more elaborate symptom in the form of a curious impulse to repeat the same word or the same exclamation. Sometimes the patient is driven to utter aloud what he would fain conceal.

The advantage of this description is its applicability to every type of tic, trifling or serious, local or general, from the simplest ocular tic to the disease of Gilles de la Tourette. Polymorphism is one of the tic's distinguis.h.i.+ng features.

Apart from his studies in objective localisation, Trousseau, as we have seen, recognised that the tic subject was mentally abnormal, but the credit of demonstrating the pathogenic significance of the psychical factor is Charcot's. Tic, he declared,[3] was physical only in appearance; under another aspect it was a mental disease, a sort of hereditary aberration.

Advance along the lines thus laid down has been the work more especially of Magnan and his pupils, of Gilles de la Tourette, Letulle, and Guinon.

A meritorious contribution to the elucidation of the question is the thesis of Julien Noir, written under the inspiration of Bourneville and published in 1893. The still more recent labours of Brissaud, Pitres, and Gra.s.set in France, and of others elsewhere, have added materially to our knowledge.

Confining ourselves for the present to the discussion of the latest interpretations put on the word tic, we may be allowed the remark that if the influence of Magnan's teaching has been instrumental in making our idea of tic conform more to the results of observation, nevertheless his view is not without its dangers.

In the opinion of Magnan and his pupils, Saury and Legrain[4] in particular, the tics do not form a morbid ent.i.ty; they are nought else than episodic syndromes of what Morel called ”hereditary insanity,” that is to say, of what is usually designated nowadays ”mental degeneration.”

Now, if by degeneration be meant a more or less p.r.o.nounced hereditary psychopathic or neuropathic tendency which betrays itself by actual physical or psychical stigmata, then tic patients are unquestionably degenerates. If degeneration unveils itself in multifarious psychical or physical anomalies, the subjects of the tic are undoubtedly degenerates.

If a degenerate may suffer from one or other variety of aboulia, or phobia, or obsession, the man with tic is a degenerate too.

Thus understood, the epithet may be applied to all individuals affected with tic. In fact, they _must_ be degenerates, if the word is to be employed in its most comprehensive sense. But the explanation is insufficient, inasmuch as the converse does not hold good; all degenerates do not tic.

We may be safe in maintaining, then, that tic is only one of the manifold expressions of mental degeneration, but we are not much enlightened thereby. Obsessions and manias similarly are indications of mental deterioration, yet the fact conveys very scanty information as to their real nature. Physical anomalies--ectrodactyly, for instance--betoken physical degeneration, no doubt; but are inquiries to cease with this categorical a.s.sertion? Such certainly was not the idea of those observers whose is the praise for having demonstrated the common parentage of the heterogeneous manifestations of degeneration.

Synthesis cannot exclude the work of a.n.a.lysis, and in practice there is scarcely a case to which this doctrine is not pertinent.

Every physical and every mental anomaly is the fruit of degeneration; every individual who is a departure from the normal is a degenerate, superior or inferior as the case may be. As instances of the latter we may specify the dwarf and the weak-willed; of the former, the giant and the exuberant. This sane and comprehensive conception of the subject must command universal acceptance as a synthetic dogma, but it cannot supplant the description and interpretation of individual facts. However legitimate be our representation of tic as a sign of degeneration, it is obviously inadequate if we rest content with styling its subject a degenerate.

Unfortunately the inclination too often is to be satisfied with the term, and to imagine that therewith discussion terminates. Still more unfortunately, in concentrating their attention on the mental aspect of the disease, some have altogether lost sight of one of its fundamental elements, viz. the motor reaction, and have conceived the possibility of its occurrence without any _tic_ at all. Cruchet actually postulates the existence of an exclusively psychical tic, with no external manifestation.

To these questions, however, we shall return. The present introductory sketch is intended merely to demonstrate the ease with which ambiguity arises, and the desirability of its removal. We are fully conscious of the value of the work of Magnan and his school in emphasising a phase of the subject the exposition of which can only result in gain.

The investigation of the motor phenomena of tic is no less encircled with perplexities. Not only are the troubles of motility boundless in their diversity and correspondingly difficult to cla.s.sify, but they also bear so close a resemblance to a whole series of muscular affections that one is tempted to describe a special symptomatology for each individual case.

For several years there has been, more especially outside of France, a manifest tendency to aggregate all convulsions of ill-determined type into one great cla.s.s, under the name ”myoclonus”; and into this chaotic farrago, it is to be feared, will tumble a crowd of conditions which should be studiously differentiated: the tics, electric and fibrillary ch.o.r.eas, paramyoclonus multiplex, etc., etc.

In the present state of our knowledge, according to Raymond,[5] we must be guided by the lessons of clinical experience, which teach us, first, that the varying modalities of myoclonus develop from the parent stock of hereditary or acquired degeneration; and, secondly, that transitional forms which do not fall into any of the received categories are of common occurrence.