Silent strokes are symptomless brain injuries caused by a blood clot that disrupts blood flow to the brain. Researchers cautioned that these brain injuries are a risk factor for future strokes.
"I do not believe migraine sufferers should worry, as the risk of ischemic stroke in people with migraine is considered small," the study's lead author, Dr. Teshamae Monteith, said in a news release from the American Heart Association. Monteith is an assistant professor of clinical neurology and chief of the headache division at the University of Miami Miller School of Medicine.
"However, those with migraine and vascular risk factors may want to pay even greater attention to lifestyle changes that can reduce stroke risk, such as exercising and eating a low-fat diet with plenty of fruits and vegetables," noted Monteith.
The study, published online May 15 in the journal Stroke, involved a multi-ethnic group of older people in New York City. Just over 100 of the study participants had a history of migraines and nearly 450 didn't experience migraines.
Of these adults, 41 percent were men with an average age of 71 years. Because Hispanics and blacks are at greater risk for stroke, the researchers noted that roughly 65 percent of the participants were Hispanic.
Using MRI scans, the researchers compared the brains of those with migraine and those without. Even after taking other risk factors for stroke into account, the evidence showed there were twice as many silent strokes among the participants with migraines.
This risk of silent stroke was increased both in people who had migraines with auras (or changes in vision), and those who had migraines without visual symptoms, according to the study.
Although previous research has linked migraine with abnormalities in the small blood vessels in the brain, the current study didn't find an increase in blood vessel changes.
The study authors noted that their findings suggest treating migraines might help lower the risk of stroke.
"We still don't know if treatment for migraines will have an impact on stroke risk reduction, but it may be a good idea to seek treatment from a migraine specialist if your headaches are out of control," said Monteith.
While the current study found an association between migraine and stroke, it wasn't designed to prove that migraines cause stroke. The researchers also pointed out that more studies are needed to confirm their findings.
The U.S. National Library of Medicine has more about migraine.