Migraines Leave Trail of Scars
Scans show brain lesions that point to cell death, but effect is unclear
TUESDAY, Jan. 27, 2004 (HealthDayNews) -- Migraine headaches can leave telltale scars in the brain that point to cell death from a possible lack of blood, new research shows.
Scientists in America and the Netherlands found that migraine patients were more likely than people not prone to the headaches to have evidence of infarctions, or dead spots, in the cerebellum, a brain region that controls motor function and some cognition. People with more frequent migraines were many times more likely to have scarring than those with occasional headaches.
The scarring, detected by magnetic resonance imaging (MRI) scans, doesn't seem tied to any functional problems. Performance on neurological tests were the same in people with and without the lesions.
"We couldn't pick up any functional problems that may be associated with the lesions," says study co-author Lenore Launer, a brain researcher at the National Institute on Aging. "That's not to say there aren't any. Our tests were not specifically designed to pick up problems in the cerebellum."
Some research has connected migraines with strokes in young women, Launer says, but the exact meaning of the scars in the cerebellum isn't clear.
"For the first time, we actually show that there are some structural brain changes that are associated with migraine. It's not just a headache, it's a more serious disorder," she says.
Other experts agree that the finding, reported in the Jan. 28 issue of the Journal of the American Medical Association, should prompt scientists to reconsider how they view migraine headaches. Rather than simply periodic attacks, migraines may in some cases be a progressive ailment that causes accumulating brain damage.
"It's pretty clear that migraine sufferer have more brain lesions" than people without the attacks, says Dr. Richard Lipton, a headache expert at Albert Einstein College of Medicine in New York City. "That strengthens the view that migraine is a neurologic disease, a disease of the brain."
More than 28 million Americans suffer migraine headaches. Women are three times more likely than men to experience the attacks, which can last anywhere from a half hour to several days.
About 15 percent of migraines are preceded by flashes of light, blind spots or tingling limbs, signs collectively called "aura". They may also be accompanied by nausea and vomiting. They may strike only one side of the head or both.
What causes migraines isn't clear, although genetics plays a strong part, Lipton says. People who suffer the headaches say they can be triggered by stress, certain foods, such as chocolate and wine, and a variety of other stimuli, Launer says.
Launer's group performed MRIs on 161 Dutch migraine patients whose headaches were accompanied by aura, and 134 without the sensory signs. They also studied 140 men and women free of headaches.
Scans revealed that brain infarctions were no more prevalent, in general, between migraine sufferers and the other volunteers, appearing in 8 percent and 5 percent of people, respectively -- a statistically insignificant difference.
However, when they looked at the cerebellum, the researchers saw striking differences. Migraine patients were about seven times more likely have signs of infarcts than migraine-free volunteers. Among migraine patients with aura, the odds of infarct were nearly 14 times higher than in people with no history of the headaches.
In patients who suffered at least one migraine a month, the odds of lesions were nine times greater, while the combination of frequent migraines and aura carried nearly a 16-fold increased risk of brain scarring.
Launer says the infarcts in the cerebellum could be caused by suppressed blood flow to the region during a migraine, "or there may be some clotting that gets thrown off in that area" during an attack.
However, she adds, the infarct isn't what sparks the headaches, but may be caused by them. Only long-term studies that track migraines and brain lesions will be able to tell for sure, she says.
Lipton says migraine patients shouldn't add brain damage to their list of worries, since the neurological exams of people with the scarring look normal. Instead, he says, the study's message should be that "early and aggressive treatment of migraines really might be the way to go."