Drugs and platelet activation in migraine and transient ischemic attacks.

In order to study the role of platelets in migraine and cerebrovascular disease, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) plasma levels, indices of in vivo platelet activation, were assayed in two groups of patients suffering from migraine (common/classic and classic/complicated migraine, respectively) and in one group suffering from transitory ischemic attacks (TIAs). Plasma determinations were carried out in the absence of treatment and during the administration of aspirin (50 mg/daily) and flunarizine (10 mg/daily). Platelet activation was found in patients suffering from TIA; patients affected by classic and complicated migraine showed a high incidence of activation, in comparison with common migraine sufferers, also in headache-free periods. Administration of aspirin (ASA) was more effective than flunarizine in inducing a decrease in beta-TG and PF4 plasma levels in migraineurs. Aspirin, however, did not affect platelet activation in subjects suffering from ischemic attack even though we did not observe any relapse after one year of treatment. The different effect of ASA in TIAs and migraine indicates that the platelet activation in TIA patients is due not only to cyclo-oxygenase pathway but also to other in vivo pathways.