Migraine thrombocytopenia, and serotonin metabolism.

Among 296 patients with thrombocytopenia, 14 had frequent migraine-like headaches, 6 of them having definite migraine. Only 1 of the 6 patients had had migraine before the onset of the blood disorder, and all 6 had migraine attacks during periods of bruising tendency and low platelet count. Control of thrombocytopenia with splenectomy or steroids was accompanied by dramatic improvement in migraine. It is suggested that migraine attacks are caused by abnormal platelet activity and abnormal serotonin metabolism. It is suggested that the immediate factor producing the abnormal platelet activity in our patients was immunological and that other cases of migraine may have an immunological cause.