THE FACT that neuroleptic drugs can cause dyskinesias other than parkinsonism or acute dystonia has been well documented by more than 50 papers. I reviewed the literature on this subject in 19681; Schmidt and Jarcho, among others, described the most important manifestations of these abnormalities in an issue of the Archives in 1966.2 It suffices to mention here that this type of disorder, also called tardive dyskinesia, is characterized by complex repetitive involuntary motility, localization in the oral region (bucco-lingual syndrome) or in the distal parts of the extremities, rocking of the pelvis and shifting of weight from foot to foot, late onset in the course of drug therapy, persistence for months or years after drug withdrawal, and failure to respond to antiparkinsonian drugs. In addition, cases have been reported in which the syndrome resembles Huntington's chorea, dystonia deformans, choreo-athetosis and various types of tics. The fact