As a general rule it is only one part or segment of the body that is immobilised by a tonic tic, but in regard to the possibility of a general involvement, the following instance[50] may be cited, although we do not think it can be considered decisive:
A man thirty-two years old, who had recovered from a first attack of mental torticollis, underwent a relapse in quite a different form. If when walking with his head perfectly straight he were asked to go round to the right, he instantly appeared to become rooted to the spot and could not turn even his head in the required direction; at the same time he felt a compression of his throat as if he were being strangled, and for a few seconds he experienced acute anguish. A moment later he was all right again, and his action unimpeded.
Without going so far as to classify this incident as a tic, and without venturing to assert the existence of a tic of immobility, one cannot but be struck with its analogy to the attitude tics of which we have been speaking, and to catatonic conditions met with in the insane, of which too the pathogeny presents more than one point of similarity with that of this species of tic.
[In this connection reference may be made to certain conditions occasionally noted among those who tic—viz. a curious tendency to maintain abnormal positions of the limbs or trunks, and difficulty in or impossibility of relaxing various muscles (catatonic aptitudes). Patients are sometimes given to the exaggerated repetition of the ordinary movements of their members (echokinesis), as well as to imitation of the actions of others (echomimia). Such catatonic and echopraxic phenomena[51] are not confined to sufferers from tic, for they are encountered among psychopathic subjects generally, and indicate defect of cortical control—what is called by Brissaud "passive activity." These catatonic aptitudes may be discovered by resort to clinical tests, such as letting the arm fall from the horizontal position.[52]]
INTENSITY OF THE MOTOR REACTION
The muscular contraction varies considerably in intensity, in most cases exceeding that of the corresponding normal movement, and, especially in tonic tics, being often so powerful as to necessitate the exertion of great force to overcome it. Even though one's effort prove unavailing, however, it is only needful to distract the patient's attention to perform any and every passive movement with consummate ease.
In the case of S., any attempt to budge the head from its torticollic position on the left evokes strong muscular resistance; but engage him in conversation or otherwise divert his mind, and the difficulty soon vanishes. By similar means, the resistance awakened by sudden change of the direction of passive rotation will rapidly die down.
Occasionally the muscles brought into play surpass their fellows of the opposite side in size and power, this secondary hypertrophy being the natural sequel of repeated exercise. It was noted by Charcot that in rotatory tics the disused muscles atrophied, whereas the affected muscles hypertrophied, but they may do so only in appearance. The tonus of the muscles at the moment of examination may create differences inappreciable during relaxation. Sometimes one comes across such expressions as "paresis" or even "paralysis" of antagonistic muscles, and "contracture" of those in which the tic is localised. To draw a distinction between slight contracture of the latter and mild paresis of the former is a problem practically always insoluble. Opinion has been ever divided on this point; yet some, in their desire to harmonise the two, take up an eclectic position and do not hesitate to speak[53] of "paralytic contracture," or "mixed contracture, at once active and passive," a terminology by no means calculated to simplify the question, and one the discussion of which we do not care to pursue.
We should like, however, to allude to a matter of clinical observation that we frequently have had occasion to remark. What simulates muscular enfeeblement in the subject of tic is often nothing else than a want of accuracy and adresse in the performance of a given movement. For instance:
S. enjoys robust health; his only trouble is a lack of accurate control over his limbs. His execution of the most elementary movements is incorrect. There is no tremor, no jerkiness, simply a loss of the sense of position. He never knows whether he is holding himself straight, whether his arms are exactly horizontal or his shoulders symmetrical. Often he confuses right and left, and when requested to perform some act on one side, he declares he is tempted to perform it simultaneously on both. The order to fold his arms and rotate the upper part of his body to the right evokes an inconceivable display of contortions. In the attempt to bend his head and body backward, fear of losing his balance causes him to twist and turn about most strangely, and the remark that all this he might avoid by merely putting one foot further back seems to cause him infinite surprise.