Intensity and frequency of movement, duration and deformity of attitude, all alike may vary in the same individual at differing times. Solitude, tranquillity, and repose favour the diminution and even the entire disappearance of spasmodic movements which fatigue, anxiety, and emotion are prone to exaggerate. An instructive case in point is one of van Gehuchten's,[96] the subject being a labourer twenty-five years old, in whom a tic of the right arm and right sternomastoid of seven years' continuance disappeared whenever the patient was by himself, to burst out afresh as soon as he was conscious of being observed. Distraction is a valuable sedative. A patient of ours used to pass the day in twisting his head round with ever-increasing violence, while at night, amid the smiling gaiety of the theatre, hours slipped by without his betraying the least suspicion of his malady. Occupation, on the other hand, may provoke the condition. Duchenne has a reference to a case where rotation of the head to the right commenced whenever the subject started to read, and ceased only with the laying down of the book. In one of our cases the head kept turning whenever and as long as the two hands were simultaneously engaged in some pursuit. If one hand was disengaged, there was no torticollis. As a general rule, excitement invites or increases movement, whereas sleep frustrates it, and after a good night's rest several minutes or even an hour or two may elapse ere the convulsions reassert themselves. Acute pain is rarely met with in the disease we are considering, but sensations of discomfort, of tension, of strain in the muscles, form a common subject of complaint. By way of example may be cited the case of one of our patients: L. is eighteen years old, and has been suffering from torticollis for the last six weeks. The chief movement is abrupt rotation and very slight inclination of the head to the right, and the muscles principally concerned are the left sternomastoid and the right splenius. The head is sunk between the shoulders, of which the right one is elevated synchronously with the rotation, and remains so as long as the latter persists. The displacement is effected by a moderately brisk muscular contraction that rotates the head to the right on its vertical axis, and succeeding contractions only serve to accentuate the deviation or to maintain it when the head is beginning to revert to its original position. There are none of those upward or downward oscillations, those hesitating, tentative little jerks that some patients make before assuming a fixed torticollis attitude. In L.'s case the duration of the wryneck is exceedingly variable; sometimes the head returns spontaneously to its place, and deviates afresh immediately after, but its periodicity changes with the days, and even with the minutes.