Migraine and stroke in young women: case-control study. The World Health Organisation Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception.

OBJECTIVE To investigate the association between migraine and ischaemic or haemorrhagic stroke in young women. DESIGN Hospital based case-control study. SETTING Five European centres participating in the World Health Organisation Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception. SUBJECTS 291 women aged 20-44 years with ischaemic, haemorrhagic, or unclassified arterial stroke compared with 736 age and hospital matched controls. INTERVENTION Questionnaire. MAIN OUTCOME MEASURE Self reported history of headaches. RESULTS Adjusted odds ratios associated with a personal history of migraine were 1.78 (95% confidence intervals, 1.14 to 2.77), 3.54 (1.30 to 9.61), and 1.10 (0.63 to 1.94) for all stroke, ischaemic stroke, and haemorrhagic stroke respectively. Odds ratios for ischaemic stroke were similar for classical migraine (with aura) (3.81, 1.26 to 11.5) and simple migraine (without aura) (2.97, 0.66 to 13.5). A family history of migraine, irrespective of personal history, was also associated with increased odds ratios, not only for ischaemic stroke but also haemorrhagic stroke. In migrainous women, coexistent use of oral contraceptives or a history of high blood pressure or smoking had greater than multiplicative effects on the odds ratios for ischaemic stroke associated with migraine alone. Change in the frequency or type of migraine on using oral contraceptives did not predict subsequent stroke. Between 20% and 40% of strokes in women with migraine seemed to develop directly from a migraine attack. CONCLUSIONS Migraine in women of childbearing age significantly increases the risk of ischaemic but not haemorrhagic stroke. The coexistence of oral contraceptive use, high blood pressure, or smoking seems to exert a greater than multiplicative effect on the risk of ischaemic stroke associated with migraine.