PLATELET SEROTONIN PATHWAY IN MENSTRUAL MIGRAINE

In order to understand the possible 5-hydroxytryptamine (5HT) anomalie s in migraine, particularly in the period before the headache attack, we compared the levels of 5HT, its stable metabolite 5-hydroxyindoleac etic acid (5HIAA) and platelet monoaminoxidase (MAO) activity in patie nts with menstrual migraine with those of healthy female controls. In every subject, blood samples were drawn during both follicular and lat e luteal phases of the menstrual cycle. In controls, platelet 5HT leve ls remained stable, whereas 5HIAA levels and MAO activity were higher in the luteal than in the follicular phase, suggesting an increased ca tabolism of 5HT which occurs physiologically just before menses. In me nstrual migraine 5HIAA levels and MAO activity showed similar changes with higher values in the luteal than in the follicular phase. The lut eal phase values were significantly higher than those of controls. Als o, and in contrast to controls, 5HT levels decreased in the luteal pha se. These data suggest that 5HT availability is reduced in menstrual m igraine, possibly due to an increased catabolism and/or to a reduced s ynthesis, and hence predisposes patients to migraine attacks.