Older migraine sufferers may have more silent brain injury

In a new study, people with a history of migraine headaches had double the odds of ischemic silent brain infarction compared to people who said they didn't have migraines. Silent brain infarction is a brain injury likely caused by a blood clot interrupting blood flow to brain tissue. Sometimes called "silent strokes," these injuries are symptomless and are a risk factor for future strokes.

Previous studies indicated migraine could be an important stroke risk factor for younger people.

"I do not believe migraine sufferers should worry, as the risk of ischemic stroke in people with migraine is considered small," said Teshamae Monteith, M.D., lead author of the study and 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."

High blood pressure, another important stroke risk factor, was more common in those with migraine. But the association between migraine and silent brain infarction was also found in participants with normal blood pressure.

Because Hispanics and African-Americans are at increased stroke risk, researchers from the Northern Manhattan Study (NOMAS) -- a collaborative investigation between the University of Miami and Columbia University -- studied a multi-ethnic group of older adults (41 percent men, average age 71) in New York City. About 65 percent of participants were Hispanic. Comparing magnetic resonance imaging results between 104 people with a history of migraine and 442 without, they found:

• A doubling of silent brain infarctions in those with migraine even after adjusting for other stroke risk factors;
• No increase in the volume of white-matter hyperintensities (small blood vessel abnormalities) that have been associated with migraine in other studies;
• Migraines with aura -- changes in vision or other senses preceding the headache -- wasn't common in participants and wasn't necessary for the association with silent cerebral infarctions.

"While the lesions appeared to be ischemic, based on their radiographic description, further research is needed to confirm our findings," Monteith said.

The research raises the question of whether preventive treatment to reduce the severity and number of migraines could reduce the risk of stroke or silent cerebral infarction.

"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," Monteith said.