Migraine-Related Brain Changes Not Associated with Impaired Cognition

Women with migraines do not appear to experience a decrease in cognitive ability over time compared to those who did not have them, according to a nine-year follow-up study.

The study also showed that women with migraine had a higher chance of having brain alterations that appeared as bright spots on magnetic resonance imaging (MRI) scans. “The fact that there is no evidence of cognitive loss among these women is good news,” said Linda Porter, PhD, pain health science policy advisor in the Office of the Director at the US National Institute of Neurological Disorders and Stroke (NINDS; Bethesda, MD, USA), which provided funding for the study. “We’ve known for a while that women with migraine tend to have these brain changes as seen on MRI. This nine-year study is the first of its kind to provide long-term follow-up looking for associated risk.”

“An important message from the study is that there seems no need for more aggressive treatment or prevention of attacks,” said Mark C. Kruit, MD, PhD, one of the lead investigators, and a neuroradiologist from Leiden University Medical Center (the Netherlands), which led the study. Dr. Kruit and coworkers assessed MRI scans for changes in the brainstem, white matter, and cerebellum that appeared on the scans as bright spots known as hyperintensities. Earlier research has revealed an association between such hyperintensities and increased risk of stroke, cognitive decline, and risk factors for atherosclerotic disease.

The quantity of MRI brain scan findings increased somewhat with time, according to the population-based study that tracked 286 men and women with and without migraines. Men with migraines had no greater incidence of such changes compared with age-and sex-matched controls. Although female participants with migraine in this study were more likely to have hyperintensities, there was no obvious relation to the frequency of migraine attacks, the type of migraine, or how they were treated.

Standardized measures of cognitive abilities such as memory, concentration, and attention did not show significant losses among people with migraine-associated lesions compared to those without migraine. The brain changes that generate the bright spots seen on MRI are unknown. More research is required, according to the investigators, to determine out if these are related to ischemia and ischemic stroke risk, according to the researchers.

The findings, which were published in the November 14, 2012, issue of the Journal of the American Medical Association (JAMA), update observations from a study performed in 2000 showing that women with migraines were more likely than age-matched controls to have scattered areas of white matter alterations on MRI scans. That initial population-based study, known as the Cerebral Abnormalities in Migraine, an Epidemiological Risk Analysis (CAMERA-1), assessed and screened 295 men and women with migraine and compared them with 140 age- and sex-matched control subjects. In that study, individuals who had more frequent migraines also had a higher incidence of changes seen on their MRIs, suggesting that migraine attacks could have a cumulative effect.

In the current study, known as CAMERA-2, researchers tried to pick out differences between men and women, and to find out whether the sort of migraine was linked with an increase in the volume of new white matter changes relative to that seen in the initial study. Researchers reassessed 286 of the original participants. Among them, 114 had migraine with aura, 89 had migraine without aura, and 83 were controls.

Compared with baseline, women with migraines were twice as likely as those without such attacks to have an increase in the volume of diffuse white matter changes. However, this increase was still very small, said one of the study’s investigators, Lenore J. Launer, PhD, chief of the neuroepidemiology section at the US National Institute on Aging (NIA; Bethesda, MD, USA).

The CAMERA-2 study also revealed no link between new brain lesions and migraine frequency. This finding may be because of the fact that structural alterations to the brain occur not with each new migraine attack, but are the consequence of an ongoing process that happens even during periods between attacks, according to Dr. Kruit.

The study participants aged, making it hard to tweak out brain alterations that are specifically attributable to migraine. That is because age, as well as hypertension and diabetes, are also known risk factors for white matter alterations, Dr. Launer clarified. Sixty percent of the control females without migraine showed progression of white matter lesions as compared to 77% of those with migraine.

These findings add to the increasing amount of data that migraine, particularly in women, is progressively related small blood vessel changes, the researchers wrote in their article.

Related Links:
National Institute of Neurological Disorders and Stroke
Leiden University Medical Center