Saint Vitus's Dance, Or Chorea, a disorder of innervation, characterized by an irregular action of the voluntary muscles, occurring usually in young persons from the age of 10 to 20 years, and more frequently in females. Its approach is heralded by languor and lassitude, slight dragging of one of the limbs, a furred tongue, general disorder of the stomach and bowels, occasionally pain in the occipital portion of the head, frequently a sense of awkwardness leading the patient to avoid the presence of strangers, and sudden muscular contortions, apparently involuntary. Gradually the muscles cease to be under the full control of the will; the head shakes upon the occurrence of the slightest excitement, and the patient cannot control its motion except by a violent and painful exercise of volition. If he attempts to carry food or drink to his mouth, the hand approaches part way and then moves off suddenly in another direction. The hands and feet will not keep still; the face is distorted by the spasmodic action of the muscles; the motions of the body in walking are very uncertain, and one leg and the opposite arm will seem paralyzed. The articulation is impeded and painful, the temper variable, and the patient exceedingly sensitive. Occasionally the action is more violent.

If watched or noticed, the spasmodic action is invariably aggravated. The most frequent predisposing causes are the changes which take place at puberty. Among the exciting causes are fright, irritation of the stomach and bowels, improper diet, and disordered menstruation. - Chorea is not usually dangerous or even obstinate, although cases have been known in which the involuntary movements were so violent and continuous as to exhaust the strength of the patient and produce death. As a general rule it is simply a manifestation of functional disturbance of the nervous system, dependent on the changes of approaching puberty; and it usually disappears spontaneously after a few weeks or months, when these changes have become fully established. The most effective treatment is hygienic: exercise in the open air, a healthy mental and bodily occupation, simple and nutritious food, the shower bath, and in some cases tonic medicines.