Tics and Their Treatment

by Henry Meige; E. Feindel

If we were to confine ourselves to this description by Sydenham, which so far as typical cases of the disease are concerned is perfectly accurate, differentiation between tic and chorea would not be a matter of any complexity. Unfortunately, however, the varieties of this form of chorea are legion, and in practice one constantly meets with conditions suggesting alike the gesticulations of chorea and the convulsive reactions of tic. Moreover, it has been pointed out by Oddo[177] that the fact of the habitual exaggeration of tic during the very years when chorea is liable to appear is calculated to confuse the issue.

He has attempted, however, to specify certain factors in the differential diagnosis. In the first instance, the form of the movements is of significance: there is no co-ordination in the muscular play of the choreic; it is amorphous, indefinable, and erratic, whereas the gestures of tic are purposive, and may be said to have a shape. One never sees in chorea a succession of similar movements, but though a patient be suffering from several tics, each of them is reproduced always in the same fashion. Unilaterality of distribution is more common in chorea than in tic; in other words, chorea, more or less, follows anatomical lines in the regions it affects, whereas the incidence of tic is physiological.

Both are arhythmic in their manifestation; nevertheless the repetition of tic is noteworthy for its regularity as compared with the changing mode and rate of the other. Noir emphasises the diagnostic value of its frequency, abruptness, and reiteration of identical movements. In a majority of cases the interference of the will is futile as far as chorea is concerned, while the victim to tic is usually capable of restraining his muscular activity at least for a space. The choreic exhibits his movements in public, but the tiqueur seeks the seclusion of his own room. The association of tic with obsessional ideas is frequently encountered, but there is no similar connection between obsessions and chorea. In addition, the myasthenia, pains, and alterations in the reflexes that often characterise chorea are awanting in the other affection.

It cannot be gainsaid, however, that the frequency with which atypical varieties of chorea occur is inimical to a ready diagnosis, and the onerous nature of the task is not lessened by the circumstance that many choreics are the offspring of neuropathic parents and reveal psychical anomalies comparable to those of the subjects of tic.

In a disease such as variable chorea, which has features in common both with tic and with chorea properly so called, the problem of diagnosis is still more complicated, though excellent hints for its solution have been furnished by Brissaud.[178]

However frequently and warmly the theory of the origin of chorea in a neuropathic predisposition was advocated by Charcot, the fact of its usual evolution consecutive to some toxic or infective process is no less certain. Its incidence is greatest in children and the adolescent; it runs a regular course of increase and decrease; and the circumstances which cause the symptoms to vary during this cycle are never sufficiently potent to bring about even transitory suppression of them.

It is true that changes in the intensity of the symptoms seem to confer a remittent character on the affection, but there is nothing at all comparable to the sudden and unexpected waxing and waning of the form of chorea at present under consideration. None of the pathological attributes just mentioned concerns variable chorea, which, in addition, differs from Sydenham's chorea in two points—the multiplicity of the types of movement, and the fact that the patient can voluntarily check his involuntary actions. For these reasons, assimilation of the two clinical varieties is impossible, and the confusion of the two in practice need never occur.

A form of chorea entitled "habit spasm" by Gowers, and "habit chorea" by Weir Mitchell, has been the subject of further study by Sinkler,[179] but in all probability the cases of this description reported are instances of the variable chorea of Brissaud.

B. Huntington's Chorea

In spite of the preponderating etiological significance of heredity and the constancy of psychical imperfections in the chronic chorea of Huntington, its confusion with tic is not at all likely to occur. Difficulties might arise in distinguishing chorea major from variable chorea, however, and here we have the views of Brissaud to help us.