Stephen Silberstein, MD: What do we know about what causes migraine? It used to be believed that migraine was the disorder of blood vessels in neurotic women: the aura they constricted, the headache they dilated. But that makes about as much sense as saying that epilepsy is due to when you shake your arm a lot with a seizure and the blood vessels dilate. Migraine is a disorder of the brain. It’s sensitive to light, to sound, to odors. They’re all in the brain. And somehow or other, this problem results in the activation of the trigeminal vascular system, which surrounds the brain and produces the signs and symptoms of migraine headache.

I would like to talk a bit about the genetics of migraine. It’s extraordinarily complicated. One variety of migraine, which is rare, is called hemiplegic migraine. Even familial hemiplegic migraine that runs in a family has a minimum of 5 different genes that cause it. But with the everyday garden-variety of migraine, the answer is not so simple. We can look at a bunch of DNA and try to figure out which gene goes to which patient, but that doesn’t tell us how these patients have migraine. Do you know what’s interesting? There’s a study about the world’s tallest man, and they tried to figure out why, of all people, he is tall. And it turns out that each gene added a little bit to the height and altogether made him tall. And the chance of that happening is about 1 in 100 million. Maybe that’s what migraine is. Each gene is adding a little bit to the picture and together they give us migraine.

Most patients have episodic migraine. Some patients develop chronic migraine. That is migraine that occurs greater than 15 or more days a month. What are the risk factors? Getting banged in the head, taking too much acute medication, overuse of caffeine, stressful life events, not getting sleep, or being overweight. These are all risk factors for the development of chronic migraine.