Young women who have migraine with aura should stop smoking, experts have said

The link between migraines and an increased risk of stroke has been confirmed by a round-up of new studies.

Migraine doubles the chances of a stroke if accompanied by aura (temporary visual or sensory disturbances) and women are at higher risk than men, according to the research, published online in the British Medical Journal (BMJ).

Other factors that heighten the chances of a stroke include being young, a smoker and using contraceptive pills containing the hormone oestrogen.

Experts led by a team from Harvard Medical School in the US said there was no evidence of an increased risk of stroke among people having migraine without aura.

"This increased risk is only apparent in those who have migraine with aura and not in those with migraine without aura, the relative risk being double," they said.

"In addition, the results suggest an approximately two-fold higher risk among women compared with men. Factors that further increased the risk of ischaemic stroke (caused by clots, accounting for 80% of strokes) were age less than 45 years, smoking, and use of oral contraceptives."

The risk was highest among young women with migraine with aura who smoked and used oestrogen-containing contraceptives.

"Young women who have migraine with aura should be strongly advised to stop smoking, and methods of birth control other than oral contraceptives may be considered," the experts said.

Around one in five people generally suffer from migraines, with up to a third of sufferers also having an aura prior to or during a migraine headache. Women are known to be up to four times more likely to suffer migraines than men.

The authors pooled the results of nine previous studies on the link between migraine and stroke to come up with their findings. They also looked at studies on a possible link with cardiovascular disease but found little evidence, although they said more research was needed.