Abstract
Prochlorperazine (Compazine, Stemetil) and chlorpromazine (Thorazine, Largactil) frequently produce tremor and rigidity. Less well known are the severe tonic spasms of the muscles of the head and neck which can result from these phenothiazine derivatives. This paper directs attention to these spasms and their similarity with “extrapyramidal seizures” and oculogyric crises.