Though migraines are known for causing frequent episodes of debilitating head and neck pain, most researchers have considered the condition to be a benign disorder, void of long-term consequences.
But now, new research has revealed that migraines may actually have a long-lasting impact on the brain’s overall structure, especially if they are coupled with an aura. And while some of these changes are considered harmless, others can lead to serious medical issues – such as increased risk for stroke.
In a new study published in the online issue of Neurology, researchers from the University of Copenhagen in Denmark and the Montefiore Headache Center in the Bronx, N.Y., conducted a meta-analysis of previous studies examining migraines through magnetic resonance imaging (MRI).
“This time, a meta-analysis is good, because a lot of studies on migraines are too small to be definitive, and the results are contradictory,” Dr. Richard Lipton, lead neurologist at the Montefiore Headache Center and co-author of the study, told FoxNews.com. “I expected to find some effects, but was particularly struck. We looked at three types of structural brain changes, and we found changes in all three that were statistically significant for people with migraine with aura.”
Migraine is a chronic neurological disorder characterized by bouts of intense throbbing or pulsing sensations in the head, often accompanied by symptoms of nausea and sensitivity to light or sound. Prior to migraine attacks, some patients suffer from what is known as an aura – a set of focal neurologic symptoms that can include seeing spots or zigzags of light, tingly feelings or numbness, and motor weakness in the extremities.
Lipton and study author Dr. Messoud Ashina, of the University of Copenhagen, reviewed six population-based studies and 13 clinic-based studies, analyzing the brain scans of people with migraines, people with migraines with aura, and people with no history of migraines. Overall they found that people who experience migraines or migraines with aura had an increased risk of white matter brain lesions, infract-like abnormalities and brain volume changes seen on MRI scans, compared to those who did not have migraines.
According to Lipton, the changes were much more pronounced in the patients who suffered from migraines with aura, who were 68 percent more likely to have white matter brain lesions. People who had migraines with no aura were only 34 percent more likely to have these kinds of lesions when compared to control subjects.
Lipton explained that white matter contains the brain’s axons – long nerve processes that link one brain region to the other. White matter lesions represent disruptions in these connections, though he said these kinds of changes shouldn’t worry patients.
“People with migraine often get MRIs, which are usually looking for some cause of migraine other than headache,” Lipton said. “But when reports come back with white matter lesions, that’s kind of scary for people. But it shouldn’t be, because as far as we know, the white matter lesions are not associated with any bad outcomes.”
Though white matter lesions are not considered particularly harmful brain changes, Lipton said the infarct-like abnormalities may actually pose a serious health risk. These changes indicate a disruption of blood flow in the brain, which can raise an individual’s risk for stroke. The risk for infarct-like abnormalities increased by 44 percent for people who suffered from migraine with aura, compared to those without aura.
“Our meta-analysis showed that the risk of these infarct-like lesions increased with how long you’ve had migraine and how many attacks you’ve had,” Lipton said. “So there’s a possibility that if you reduce migraines with aura, you might be able to reduce your risk of stroke… So try to avoid factors that trigger headaches and use medications that are preventative of migraines.”
The third and final brain change seen in the review was volume loss in the brain’s grey matter, the part of the brain where the bodies of the nerve cells sit. This shrinkage can be associated with certain kinds of memory loss, but Lipton said this isn’t necessarily a permanent side-effect for all migraine sufferers.
“One of the really fascinating things is that when migraine is well controlled, the shrinkage reverses,” Lipton said. “It’s not that the migraine is killing nerve cells, it seems that migraine is resulting in shrinkage of nerve cells. So if frequent migraine stops, the nerve cells can grow back and replace the volume lost. That creates another argument for reducing migraine frequency and severity with behavioral therapy.”
Migraine affects about 10 to 15 percent of the general population, and about a third of those patients suffer from the additional aura. Lipton hopes that his research will encourage the millions of individuals with this painful condition to seek treatment, as migraines may be more than just painful headaches.
“It’s a problem that causes pain and temporary interference with function, and it could have long-term consequences,” Lipton said. “So if you treat migraine better today, it will help you this week, and next month, and it may protect you in the long-term by protecting you from serious vascular problems.”