Risk of ischaemic stroke in people with migraine: systematic review and meta-analysis of observational studies.
OBJECTIVE
To explore the association between migraine and risk of ischaemic stroke.


METHODS
Systematic review and meta-analysis.


METHODS
Observational studies published between 1966 and June 2004 (identified through Medline and Embase) that examined the association between migraine and risk of ischaemic stroke.


RESULTS
14 studies (11 case-control studies and 3 cohort studies) were identified. These studies suggest that the risk of stroke is increased in people with migraine (relative risk 2.16, 95% confidence interval 1.89 to 2.48). This increase in risk was consistent in people who had migraine with aura (relative risk 2.27, 1.61 to 3.19) and migraine without aura (relative risk 1.83, 1.06 to 3.15), as well as in those taking oral contraceptives (relative risk 8.72, 5.05 to 15.05).


CONCLUSIONS
Data from observational studies suggest that migraine may be a risk factor in developing stroke. More studies are needed to explore the mechanism of this potential association. In addition, the risk of migraine among users of oral contraceptives must be further investigated.
Etminan
Mahyar
M
Division of Epidemiology, Royal Victoria and Vancouver Hospitals, Canada. Mahyar.etminan@mail.mcgill.ca
Takkouche
Bahi
B
Isorna
Francisco Caamaño
FC
Samii
Ali
A
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000209:etiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000009:adverse effects; D003430:Cross-Sectional Studies; D006801:Humans; D008875:Middle Aged; D008881:Migraine Disorders / Q000150:complications*; D012044:Regression Analysis; D012307:Risk Factors
D003276:Contraceptives, Oral