To anyone but a neurologist, Patrick Rennich's migraines would seem a curse. With perverse regularity, they strike after he plays sports like soccer or basketball--anything that requires sprinting up and down a field or court. Not long before he's hit with nauseating pain on one side of his head, Rennich experiences something called a visual aura--a neurological disturbance that starts with a slowly expanding blind spot near the center of his left visual field. Soon after, Rennich sees static, like on a television screen. The aura looks "like I'm moving through boiling water." The pattern is so predictable that Rennich, a 28-year-old electrical engineer from Acton, Massachusetts, can say, "If you want me to get a migraine with aura at two in the afternoon, I can give you a migraine with aura at two." That's exactly what neurologist Michael Cutrer wanted. Based at both Boston's Massachusetts General Hospital and Brigham and Women's Hospital, Cutrer had been looking for someone like Rennich for years. The neurologist hoped that a magnetic resonance imaging (MRI) scan of such a patient's brain during the aura would provide clues to what happens inside his skull. Before 1998, no one had done this, and for good reason: Almost no migraine sufferer can summon an aura on command, and few are willing to lie in a claustrophobia-inducing MRI tube to wait for one to occur. Cutrer had come across a few prospects, but none had worked out. One patient promised that raw onion would do the trick, "but we had him lying in there crunching away--and nothing," says Cutrer. Rennich seemed worth a try, so Cutrer asked him and his wife, Jean, to come to the ymca next door to his research lab. The couple played games of free throws, the loser running sprints back and forth across the basketball court, with one modification: "If I lost, I ran," says Rennich. "And if my wife lost, I also ran."
After an hour, Rennich began to notice distortions in his vision and hustled next door to the lab, where he lay prone inside the opaque white tube of the mri machine. Once in, he focused his eyes on an alternating checkerboard pattern projected onto a screen inside the tube. Meanwhile, the mri monitored the activity in Rennich’s cerebral cortex, specifically the sections that control vision. Later, the results would be processed and color coded—red indicating areas of high neural activity, hues of orange and yellow showing lower levels, and white corresponding to the smallest amount. According to the mri results, 38 minutes after Rennich entered the tube, an area of darkness—of no color at all—appeared on the image of his brain, indicating that the neurons in a small region of the cerebral cortex were no longer transmitting visual information. The region grew slowly, “like ripples from a pebble tossed into a pond,” says Cutrer. Rennich’s aura had begun.
A decade ago, Rennich’s doctor would never have examined his brain to find the source of his migraine. In fact, the idea that the brain itself could be causing the problem has been difficult for headache researchers to accept. “Even as little as 15 years ago it would have been almost heresy to suggest it,” says Peter Goadsby, a neurologist at University College London. For one thing, the brain itself feels no sensation, even if jabbed with a probe through an incision in the skull. “Since the brain is insensate, the pain of a headache lies in the periphery, so that is where many assumed the problem was,” says Goadsby. But growing evidence implicates the brain as not just an accessory to pain but as the prime suspect.
