DYSTONIA

HISTORICAL REVIEW During the fourteenth and fifteenth centuries epidemics of dancing occurred. They were apparently hysterical in nature, as far as can he judged from contemporary accounts. The condition finally came to be known as Vitus' dance because some of the victims recovered at the shrine of St. Vitus, in Saverne, France. This term was subsequently applied to all disorders characterized by hypermotility, whether they were neuroses or psychoses or were clearly the result of lesions of the nervous system. Paracelsus attempted an etiologic classification, differentiating imaginativa, the dancing sickness, from lasciva, caused by sexual desire, and chorea due to physical causes. Subsequently the pattern of the abnormal behavior was studied more thoroughly. Horst (1623) reported a case in which the abnormal movements did not resemble dancing but were described as simple movements of the limbs. Sydenham 1 (1685) distinguished for the first time the peculiar involuntary