Evidence of enhanced platelet aggregation and platelet sensitivity in migraine patients.

In fourteen untreated migraine patients with a mean age of 40 years platelet sensitivity to 5HT, EN and ADP was investigated during the prodromal phase (three patients), 12-48 h after headache (three patients) and during the headache-free period (eight patients). Platelet sensitivity was tested using an optical density method and was calculated by the percentage of disaggregation (%DA) occurring 3 min after the peak aggregation. Platelet release reaction was assessed using beta-thromboglobulin (beta-TG) as an indicator. Platelet sensitivity to low concentrations of 5HT, EN and ADP (0.3 X 10(-9) M/ml) was most marked during the headache and prodromal phases. The least platelet sensitivity in migraineurs was detected during the headache-free interval, but was still higher than in the control group. beta-TG levels were increased during the headache phase indicating platelet release reaction. A general hyperaggregability of platelets in migraineurs has been demonstrated and in addition a varying sensibility of platelets to low concentrations of 5HT, EN and ADP has been established.