[Platelet aggregation in migraine and other headaches]

In 43 patients with migraine, 20 with Horton's headaches, 13 with trigeminal neuralgia and 50 healthy subjects the circulating platelet aggregates were determined by the method of Wu and Hoak. Moreover, in 23 patients with migraine, 8 with Horton's headache and 21 healthy subjects spontaneous platelet aggregation was determined in platelet-rich plasma with a transmission aggregometer. It was found that the aggregation coefficient was much lower in patients with migraine and Horton's headache than in the control group. In the group with migraine the per cent of spontaneous aggregation in 8 patients differed significantly from the mean value which was similar to that in the control group or in the group with Horton's headache. In the light of these results the authors conclude that significant changes of platelet aggregation occur in migraine and Horton's headache.