Platelet aggregability in migraine.

Employing optical density methods, platelet aggregation in response to 1.275, 1.7, and 3.4 micrometer adenosine diphosphate was tested in 46 patients with migraine and 46 controls matched by age, sex, and race. The migraine patients demonstrated platelet hyperaggregability when compared with controls, as manifested by a lower threshold for the platelet-release reaction and increased platelet stickiness following aggregation. There was no correlation of platelet hyperaggregability with the severity of migraine or with the occurrence of migraine-associated neurologic symptoms, suggesting that platelet hyperaggregability is a concomitant feature of the migraine syndrome but not dependent on the occurrence of the actual headache. As platelet hyperaggregability may predispose to development of intravascular platelet aggregates or mural thrombi, the hyperaggregability found here may help explain the increased incidence of stroke and heart attack in migraine patients that has been reported elsewhere.