Involuntary movements in patients taking oral contraceptives.

Involuntary movements developed in five women taking oral contraceptives. In one, the sudden onset of a unilateral disturbance suggested a cerebral thrombosis; this case is considered to be a further example of the increased risk of cerebrovascular disease associated with oral contraception. The four other patients suffered a relapse of Sydenham's chorea between one and four months after starting an oral contraceptive regimen. Possibly an underlying vascular mechanism was responsible for these relapses.