The findings may change the way we think about migraines, say study researchers Mark C. Kruit, MD, of Leiden University, Netherlands, and Lenore J. Launer, PhD, chief of the neuroepidemiology section at the U.S. National Institute on Aging.
"This is not just a headache we are talking about," Launer tells WebMD. "These findings could change the basic way of seeing migraine from an episodic disorder to something that is more chronic -- where something happens in your brain as a result of the attacks."
"The findings of this study will change the common perception that migraine only is a 'trivial problem' with only transient symptoms, into [seeing] that migraine may be a chronic-progressive disorder that may cause permanent changes in the brain," Kruit tells WebMD.
The findings, reported in the Jan. 28 issue of The Journal of the American Medical Association, don't spell doom for people with migraines. But they do suggest that people who suffer severe headaches should see a doctor -- and get effective treatment as soon as possible.
Brain Scans Show Lesions
One problem with migraine studies is that they often look only at patients seen in clinics. Yet as many as half of real-world migraine sufferers don't ever see a doctor. To get a sense of real-world migraine, Kruit's team went out and recruited Dutch adults age 20 to 60. Those who seemed to have migraines, based on a screening questionnaire, underwent further testing.
Eventually, the researchers came up with 161 people who had migraine with visual or sensory symptoms known as aura, 131 people who had migraine without aura, and 140 people without migraine. All of these people then underwent a 25-minute brain scan with a highly sensitive MRI device. The scans were able to detect very small lesions in the brain.
Unexpectedly, about 38% of the people without migraines had tiny brain lesions.
"Based on that, one could argue that having only a few incidental small lesions is quite normal," Kruit says. "However, we calculated a total volume of lesions for each subject and determined a level of 'high deep white matter lesions load.' In analyzing this group vs. the rest, we found female migraine patients to be at twofold increased risk. Having a small number of incidental small lesions might be not that abnormal, but larger numbers of larger lesions at a younger age is what makes our finding in migraine-women remarkable and significant."
Women with migraines -- but not men with migraines -- were more likely to have these brain lesions. The more frequent their migraines, and the more they had migraine with aura, the more likely they were to have brain lesions.
"It is not clear why women are at more risk, and why they have more of these lesions," Launer says.
Some of the people in the study had infarcts: areas of dead brain cells. Men and women who had migraine with aura were nearly 14 times more likely to have infarcts in a particular area of the brain -- the cerebellum -- than normal people.
Donald B. Penzien, PhD, director of the head pain center at the University of Mississippi, Jackson, says the findings confirm his clinical impression of migraine.
"This makes sense. It matches up with the clinical symptoms of people with severe migraines," Penzien tells WebMD. "It shows that migraine is a brain disease."
Will Treating Migraine Prevent Brain Damage?
The study doesn't show whether these brain lesions really mean problems for people with migraine. And it didn't look at the question of whether early treatment might help.
"At this moment, the findings do not have a direct consequence for the management of migraine patients," Kruit admits. "Further studies are needed to assess whether the brain lesions have a clinical correlate. If so, preventing accumulation of brain lesions may be an additional goal in managing migraine patients: for instance, by risk factor modification, preventive therapy, or early abortion of migraine attacks."
Launer urges patients to remain calm.
"People don't need to run to their doctors to get an MRI," she says. "As for any health risk, you need to take care of yourself, and if you have migraine headaches, go to the doctor and see what he or she can do for you."