[Migraine and stroke]

Both migraine and stroke are common illness. However, each disorder usually occurs in different generation, migraine in younger, while stroke in elder, and seems to have little in common. Migraine has been supposed to be benign, not life-threatening illness occurring throughout the life-time. Whereas, stroke is an acute illness with certain degree of disabilities consequently, even fatal in case. In spite of such differences, some of recent studies suggested migraine as a risk factor of stroke or subclinical brain damage. There seems to be several types of stroke associated with migraine. One is "migrainous infarction", which is defined as one or more migrainous aura symptoms associated with an ischemic brain lesion in appropriate territory demonstrated neuroimaging, in the International Classification of Headache Disorders (ICHD-II). The other is stroke occurring in those who had been suffering from migraine in their younger time. The former is seldom to observe, and the latter is in dispute. Recent elaborate epidemiological studies disclosed the risk of stroke is increase in people with migraine, particularly marked in those with migraine with aura, further increased in those taking oral contraceptives. However, several issues such as strict diagnostic criteria for stroke and migraine, history of medication for migraine treatment, etc. for those studies should be settled. The well organized prospective studies for the issue "migraine as a risk factor of stroke" should be considered necessary.