The significance of blood serotonin levels in migraine. A critical review.

Available evidence indicates that serotonin located within platelets--or lack of it--does not precipitate migraine attacks, and that intravenously administered serotonin is beneficial in migraine. On this premise, it is not likely that the beneficial effect of intravenously administered serotonin is due to replacement of lost intracellular serotonin. If serotonin is effective in relieving migraine pain, this is probably due to extracellular serotonin acting on the cardiovascular system. In other words, serotonin-induced relief in migraine is probably caused by the pharmacological properties of the amine--it probably acts as a drug and not by replacement. The serotonin changes in migraine are probably not primary, but caused by the disease process. Platelets may nevertheless be of importance in the pathogenesis of migraine, and serotonin may be of even more interest. However, interest in platelet serotonin will probably be diminishing in the future.