About 28 million Americans suffer from migraine headaches, yet millions go without treatment. They may not realize that the pain they experience is from a migraine and not some other headache, or their doctor may not recognize the symptoms. As a result, while one-fifth of sufferers are candidates for medicines that can cut frequent attacks in half, less than one million actually get preventative therapy. It now appears that even those who do get therapy may not be getting the most effective kind. New studies show that migraines are not caused by abnormally dilated blood vessels, but by a unique disorder of brain cells.
Migraine sufferers have abnormally excitable neurons in the brain.
New imaging devices show that when a migraine is triggered, these neurons fire electrical impulses that ripple across the brain, then down into the brainstem where they activate the pain centers. Blood flow to the brain surges until the wave passes, then the flow drops sharply. Blood vessels become inflamed by the rapid changes in blood flow, and this inflamation combined with the brainstem activation are the causes of migraine pain. The over-excitable neurons can be triggered in the laboratory. When scientists used a powerful magnet to stimulate the neurons, people disposed to migraines showed the familiar pattern of neuron firings.