Migraines With Aura Magnify Stroke Risk
Women With Frequent Attacks Face Biggest Risk
Nov. 20, 2002 -- Women who suffer from a migraine with aura are up to 10 times more likely to suffer a stroke, according to a new study.
Auras affect about 15% of the estimated 28 million Americans who suffer from migraine headaches, according to the National Headache Foundation. Auras usually precede the impending headache by up to an hour and may come in the form of vision problems, such as bright or flashing dots, blind spots, or distorted vision, or other sensory disturbances.
Although previous research has already linked migraine to an increased risk of stroke, researchers say this is one of the first studies to look at whether the type of migraine, age of onset, and attack frequency affect the risk of stroke among women.
The findings appear in the December issue of the Journal of Neurology, Neurosurgery and Psychiatry.
The researchers compared 86 women who had a stroke caused by a blockage of the blood supply to the brain to more than 200 women who were admitted to the hospital for other reasons. These clot-related strokes -- called ischemic strokes -- account for more than 80% of all strokes.
They found that the risk of stroke was four times higher in women who had migraines for more than 12 years. But the risk was even higher among women who had migraines with auras.
Women whose first migraine was accompanied by aura were eight times more likely to suffer a stroke. And the risk was 10 times higher among women who continued to have migraines with aura more than once a month.
The age at which the women began having migraines did not seem to affect stroke risk.
Although the heightened risk associated with migraine is significant, lead researcher Michael Donaghy, MD, stresses that strokes are still very rare among women in this age group -- about 15 strokes per 100,000 women. Donaghy is with the department of clinical neurology at Radcliffe Infirmary in Oxford, U.K.
Even so, experts say this study provides yet another reason for migraine sufferers to get proper treatment in order to prevent and reduce the frequency of the attacks.
"From this study it appears that those with more frequent migraines with aura have more medical complications, such as stroke," says Merle Diamond, MD, associate director of the Diamond Headache Clinic in Chicago.
If patients have frequent migraines with aura, Diamond says they should make every effort to reduce all other risk factors for stroke, such as quitting smoking and keeping their blood pressure and cholesterol under control.
Diamond says migraine patients should also let their doctor know if their type or frequency of migraine changes, because it could be an early warning sign for stroke.
"Forewarned is forearmed," says Diamond. She says these findings should have an impact on the how doctors counsel their patients about treatment decisions in order to reduce potential risks.
For example, the use of oral contraceptives is thought to slightly increase the overall risk of stroke in women with migraine, and women who suffer frequent migraine with aura should discuss birth control options with their health care provider.
"It's important that we allow these patients to use only low-dose oral contraceptives," says Diamond.
The researchers point out that no additional risk of stoke associated with oral contraceptive use was found in the study. But more research is needed to determine the true association among oral contraceptives, migraines, and stroke.
"This issue is to look at the overall risk factors, and people with frequent migraine with aura may want to stay away from things that might increase their risk."