Migraine attacks may add to risk of strokes

That head-splitting migraine attack that knocks you off your feet may also put you at risk of permanent changes in the brain, an analysis of 19 medical studies found.

The potential for increased abnormalities in the signalcarrying white matter of the brain appears strongest among those who suffer headache warning symptoms, such as flashes of light, blind spots and tingling, according to the analysis published online on Wednesday in the journal Neurology. Those "migraine with aura" sufferers were about 1.7 times as likely to have such anomalies than were the non-migraine population, the analysis found.

But the significance of these white-matter blips and other tissue changes remains elusive, and there is some question about whether the neurological variances from the norm mark a migraine-prone brain or the ravages of the attacks, researchers said.

At best, doctors have concluded that what they see on patients' magnetic resonance imagery amounts to a "benign imaging correlate" of migraine. They're there, they are associated with migraine, and that's where the hard evidence stops.

"Part of the message I hope to communicate here is: If you have migraine with aura and you have white-matter lesions, they're probably not a cause of concern," said study coauthor Dr Richard B. Lipton, a neurologist who heads the Montefiore Headache Centre in the Bronx, New York.

Migraine headaches affect 10 to 15 per cent of the population, and about a third of those experience aura symptoms, according to the study. The symptoms can cause substantial impairment and hardship, including lost work hours and high medical costs.