Case-control study of migraine and risk of ischaemic stroke in young women.

OBJECTIVE

To determine whether migraine is a risk factor for ischaemic stroke in young women.

DESIGN

A case-control study.

SETTING

Five hospitals in Paris and suburbs.

SUBJECTS

72 women aged under 45 with ischaemic stroke and 173 controls randomly selected from women hospitalised in the same centres.

MAIN OUTCOME MEASURES

Ischaemic stroke confirmed by cerebral computerised tomography or magnetic resonance imaging; history of headache recorded with structured interview, and diagnosis of migraine assessed by reproducibility study.

RESULTS

Ischaemic stroke was strongly associated with migraine, both migraine without aura (odds ratio 3.0 (95% confidence interval 1.5 to 5.8)) and migraine with aura (odds ratio 6.2 (2.1 to 18.0)). The risk of ischaemic stroke was substantially increased for migrainous women who were using oral contraceptives (odds ratio 13.9) or who were heavy smokers (> or = 20 cigarettes/day) (odds ratio 10.2).

CONCLUSIONS

These results indicate an independent association between migraine and the risk of ischaemic stroke in young women. Although the absolute risk of ischaemic stroke in young women with migraine is low, the reduction of known risk factors for stroke, in particular smoking and use of oral contraceptives, should be considered in this group.