Halos, auras, flashes of light, pins and needles running down your arms, the sudden scent of sulfur—many symptoms of a migraine have vaguely mystical qualities, and experts remain puzzled by the debilitating headaches' cause. Researchers at Harvard University, however, have come at least one step closer to figuring out why women are twice as likely to suffer from chronic migraines as men. The brain of a female migraineur looks so unlike the brain of a male migraineur, asserts Harvard scientist Nasim Maleki, that we should think of migraines in men and women as "different diseases altogether."
Maleki is known for looking at pain and motor regions in the brain, which are known to be unusually excitable in migraine sufferers. In one notable study published in the journal Brain last year, she and her colleagues exposed male and female migraineurs to painful heat on the backs of their hands while imaging their brains with functional MRI. She found that the women had a greater response in areas of the brain associated with emotional processing, such as the amygdala, than did the men. Furthermore, she found that in these women, the posterior insula and the precuneus—areas of the brain responsible for motor processing, pain perception and visuospatial imagery—were significantly thicker and more connected to each other than in male migraineurs or in those without migraines.
In Maleki's most recent work, presented in June at the International Headache Congress, her team imaged the brains of migraineurs and healthy people between the ages of 20 and 65, and it made a discovery that she characterizes as "very, very weird." In women with chronic migraines, the posterior insula does not seem to thin with age, as it does for everyone else, including male migraineurs and people who do not have migraines. The region starts thick and stays thick.
We don't know yet whether the thickening of the insula is something the brain is doing to protect itself or something that worsens women's migraines, Maleki says. Yet the evidence is mounting that when it comes to migraines, men's and women's brains are structurally and functionally different. For treatment, that knowledge could make a huge impact: not only should researchers be better about testing potential migraine drugs on men and women separately, Maleki says, but they may be able to design new treatments based on these brain differences—giving both sexes a better chance at relief.