Migraine and risk of ischaemic stroke: a case-control study.

Abstract
OBJECTIVES--To determine whether migraine is a risk factor for ischaemic stroke. DESIGN--A case-control study. SETTING--Two hospitals in Paris. SUBJECTS--212 patients with stroke (137 men and 75 women) and 212 controls matched for sex, age (to within five years), and history of hypertension. MAIN OUTCOME MEASURES--Ischaemic stroke, confirmed by brain computed tomography or magnetic resonance imaging, and history of headache, recorded with structured questionnaire during interview. RESULTS--Prevalence of migraine did not differ between patients with stroke and controls: 18/137 v 17/137 for men (odds ratio 1.1 (95% confidence interval 0.5 to 2.2), p = 0.86); 23/75 v 17/75 for women (odds ratio 1.6 (0.7 to 3.5), p = 0.24); and 41/212 v 34/212 for both sexes (odds ratio 1.3 (0.8 to 2.3), p = 0.33). When subjects were split into two age groups, however, prevalence of migraine was significantly higher among younger women (aged < 45) with stroke compared with their controls (13/20 v 6/20, odds ratio 4.3 (1.2 to 16.3), p = 0.03). Furthermore, the risk of ischaemic stroke was higher among younger women who smoked (7/20 v 1/20, odds ratio 10.2 (1.1 to 93.3)). CONCLUSIONS--Prevalence of migraine was not different between patients with stroke and matched controls except among women aged < 45, when migraine and stroke were significantly associated.