Migraines afflict three times as many women as men; by some estimates, a quarter of all women suffer the headache and visual disorders that characterize the condition. New research shows that the cause may be a distinct pattern of neural activity that can be more readily induced in women.
Female brains have a lower threshold for a phenomenon called cortical spreading depression (CSD), concludes a study by Andrew Charles, Kevin Brennan and colleagues at the University of California, Los Angeles. Charles notes that “depression” is a misnomer: CSD was first identified as a decrease in electrical activity, but subsequent research showed it to result from an initial burst of intense activity across the cortex. Inducing this wave of activity is a standard means of studying migraine in rodents.
Reporting in the June Annals of Neurology, the investigators found that, in mice, CSD could be triggered by lower levels of stimulation in females than in males—suggesting that this phenomenon explains the greater prevalence of migraine in women.
The central role of CSD, and its value as therapeutic target, is confirmed in the September issue of the Journal of Headache Pain. Charles and colleagues treated 54 migraine patients, both men and women, with memantine—a drug that works by blocking CSD and is approved by the Food and Drug Administration for treating Alzheimer’s disease. In a follow-up questionnaire, more than half of the patients reported that their headaches were half as frequent and of much less severity. Almost all of the patients had tried other medications without success.
“Our laboratory observations have translated smoothly into a promising new treatment,” Charles concludes, adding that the preliminary finding will need to be confirmed by a formal clinical trial now in preparation.