Stroke and migraine in the Oxfordshire Community Stroke Project.

A total of 323 cases of first-ever stroke were registered in the first 2 years of the Oxfordshire Community Stroke Project. Of these patients, 244 (76%) had a stroke due to cerebral infarction. There was a past history of migraine headaches in 56 (17%) of the 323 cases of stroke and in 44 (18%) of the 244 cases of cerebral infarction. A past history of migraine headaches was no commoner in patients with stroke due to cerebral infarction than in those with stroke due to intracranial haemorrhage. One hundred and seventy-three (71%) patients with cerebral infarction had at least one risk factor for ischaemic stroke; the frequency of such risk factors was similar in patients with and without a history of migraine. In 7 (3%) of the 244 patients the cerebral infarction was presumed to be "migrainous"; however, only 3 of these 7 (1.2% of the 24) were free of risk factors for ischaemic stroke. If all 7 cases were considered migrainous, the incidence rate of first migrainous cerebral infarction was 3.36 per 100,000 per year (95% confidence limits 0.87-5.86). If only the 3 patients who were free of risk factors were included, the incidence was 1.44 per 100,000 per year (95% confidence limits 0-3.07).