The Inca used to treat headaches by drilling a hole in the skull. The French favored cold compresses. Today we use shelffuls of heavily advertised over-the-counter remedies: aspirin, Advil, Tylenol, Aleve. But how much do scientists really know about headaches and what causes them? Quite a bit, as doctors who gathered in New York City last week for a meeting of the American Association for the Study of Headache can attest.
First, some background. Researchers have known since the 1960s that not all headaches are the same, medically speaking. Tension headaches, which are the easiest to treat, are triggered by clenched muscles in the head and neck. Migraines, which generate a throbbing pain that is sometimes preceded by an "aura" and can last 12 to 24 hours, are produced by blood vessels that alternately constrict and expand. Cluster headaches are even worse than migraines--if you can imagine such a thing--and scientists suspect that overactive blood vessels play a role in them too. One of the hallmarks of cluster headaches is that they strike in cycles. A victim, typically a man, may experience three or more a day for several weeks, then nothing for a year.
The meeting in New York didn't produce an all-purpose cure for the headache, but it did mark progress on several fronts:
BETTER SCREENING TESTS One of the things that make the treatment of severe headaches so difficult is that doctors don't know in advance what they are dealing with. Most physicians use trial and error: they prescribe a treatment and if it doesn't work, they try another until they find a remedy. Now scientists at Ohio University are trying to cut through some of that guesswork by fashioning a simple 15-min. screening test that will tell doctors where the pain occurs, how debilitating it is and what other factors (such as stress) may be contributing to it. The hope is that physicians will be able to determine in advance whether their patients will respond better to drugs or to, say, stress-management therapy--and get the treatment right the first time.
BETTER DRUGS Researchers have long known that a brain chemical called serotonin plays an important role in triggering migraine headaches. For reasons that are still unclear, serotonin sometimes floods the blood vessels of the brain, causing them to constrict. The body then overreacts, sending serotonin levels plummeting and forcing the blood vessels to expand to several times their normal size. This cycle of contraction and expansion results in the headache's characteristic throbbing pain. In 1993 Glaxo introduced a drug called Imitrex that allowed doctors for the first time to prescribe something that was specifically designed to interrupt the cycle of pain. Last week Glaxo announced encouraging results for its second-generation migraine medication, a new drug called Amerge that lasts longer than Imitrex and is less likely to trigger unpleasant side effects. The FDA is considering Amerge for approval.