Those with fewer-than-monthly migraines had a 45 percent increased risk of having an ischemic stroke (one resulting from constricted blood flow) and a 64 percent increased risk for heart attack, compared to women with no migraines, the Boston team found.
Women who suffered migraines at least weekly had a 49 percent increased risk for heart attack and almost triple the increased risk for stroke, they added.
According to Lipton, repeat migraine attacks may have a direct influence on the risk of stroke. "This is plausible because, during the aura, there are profound changes in the brain which diminish blood flow to the brain," he explained. "Stroke is usually caused by diminished blood flow to the brain."
If this were true, preventing migraines should decrease the risk of stroke, although this hypothesis has not yet been tested.
It's also possible that frequent migraines simply point to an increased risk for stroke, rather than actually causing it, Lipton said.
Either way, there's no reason to panic.
"Even if the relative risk of stroke triples in those with frequent migraine, the absolute risk for most people remains low," Lipton said. "If someone who would otherwise have a stroke risk of 20 per 100,000 has that risk triple due to frequent migraine -- to 60/100,000 -- they are [still] very unlikely to have a stroke."
Find out more about migraines at The National Migraine Association.
SOURCES: Richard B. Lipton, M.D., professor and vice chairman, neurology, professor of epidemiology and director of population health, Montefiore Headache Center, New York C
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