Two new studies have found that migraine sufferers who experience visual disturbances called auras may face a higher risk of stroke. One of the studies, presented on Wednesday at the American Stroke Association’s annual meeting, reported that people with migraines with auras may be as much as 2.4 times more likely to have a stroke than are migraine sufferers who do not see auras.
The second paper, also being presented at that meeting, says that women who take the female hormone estrogen may also be at risk, 30 percent more likely to suffer a clot-based stroke than women who do not take estrogen, which is found in birth control pills and hormone replacement therapy.
Dr. Elizabeth Loder, chief of Brigham and Women’s Hospital’s headache and pain division, says the two factors pose a dangerous mix. “Women who have migraines with aura probably want to think more carefully about the potential risk of stroke associated with using estrogen,” she said. However, although the studies found associations between stroke risk, migraines with auras and estrogen therapy, they did not prove cause-and effect.
Dr. Souvik Sen, neurologist at the University of South Carolina School of Medicine, says future research into blood flow patterns in the brains of patients who have migraines with auras is necessary. He says auras are an effect on the blood vessels of the brain caused by a migraine.
Regarding the estrogen connection, Loder says that estrogen increases the likelihood of blood cloths, thus increasing stroke risk.
The researchers analyzed data from the Women’s Health Initiative for more than 82,000 women aged 50 to 79. The study was begun in the early 1990s by the U.S. National Institutes of Health. All participants reported having migraines and about 45 percent also used hormone replacement. The women completed a questionnaire at a follow-up visit three years later that assessed if their migraines had worsened.
The findings suggest that women whose migraines worsen while taking hormone-replacement therapy appear to be at 30 percent higher risk for a clot-based stroke than migraine sufferers who never took hormone-replacement therapy, or had stopped the medication.
Loder says that risks can be minimized for migraine sufferers or women taking estrogen by addressing more important risk factors such as controlling blood pressure, quitting smoking, lowering cholesterol, or treating their diabetes.