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 Organisatio
n Collaborative Study of Cardiovascular Disease and Steroid Hormone Contrac
eption.
Subjects 291 women aged 20-44 years with ischaemic, haemorrhagic, or unclas
sified 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), a
nd 1.10 (0.63 to 1.94) for all stroke, ischaemic stroke, and haemorrhagic s
troke respectively. Odds ratios for ischaemic stroke were similar for class
ical 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, coe
xistent use of oral contraceptives or a history of high blood pressure or s
moking had greater than multiplicative effects on the odds ratios for ischa
emic 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 d
irectly from a migraine attack.
Conclusions Migraine in women of childbearing age significantly increases t
he risk of ischaemic but not haemorrhagic stroke. The coexistence of oral c
ontraceptive use, high blood pressure, or smoking seems to exert a greater
than multiplicative effect on the risk of ischaemic stroke associated with
migraine.