Migraine attacks and increased platelet aggregability induced by oral contraceptives.

A case where common and complicated migraine attacks appeared during the course of oral contraception is reported. The attacks of complicated migraine also continued to appear after the contraceptives were stopped. Increased platelet aggregability was found at the time when the complicated migraine attacks were frequent and, therefore, treatment with dipyridamole and aspirin was given. At the time when a gradual reduction of the platelet aggregability was observed, a decrease in the frequency, and eventual disappearance of the complicated migraine attacks was simultaneously seen. Causal relationship between increased platelet aggregability and complicated migraine attacks is suggested.