Researchers Make Headway in Migraine Relief : * Health: While new therapies emerge, neuroscientists also gain a better understanding of the precise mechanisms of racking pain as well as what triggers it.
It’s a finding that will set trend watchers to scratching their heads. According to a new study by the National Center for Health Statistics (NCHS), the incidence of migraine headaches rose an astonishing 60% in the 1980s--from 26 out of 1,000 adults surveyed at the beginning of the decade to 41 at the end.
Why the boom? Medical researchers speculate that the reasons range from air pollution to economic stress to the growing willingness of Americans to admit they have the ailment. Whatever the reason, it now seems that along with personal computers, MTV and biking shorts, the much-maligned ‘80s will also be remembered for headaches.
Whether even more Americans will endure such agonies in the ‘90s is unknown. But new therapies are emerging. One drug, sumatriptan, not yet available in the United States, was recently shown in clinical trials to ease and even prevent migraines and cluster headaches, so named because they strike repeatedly, in groups. In the meantime, neuroscientists have come closer to understanding the precise mechanisms of racking pain as well as what triggers it.
A sign of growth in headache research surfaced last summer at the International Headache Congress in Washington. Among the many findings presented was a survey of 136 patients at the University of Minnesota’s headache clinic indicating only 30% with chronic headaches were fully satisfied with their treatment; 45% said their medication didn’t work; and about one out of three patients were miffed that physicians didn’t know enough about their condition.
Headaches in all their maddening forms are the most common health complaint, striking 90% of the population at least once a year and prompting perhaps as many as 80 million doctor visits. There are three principal types of headache: migraine, cluster and tension.
Migraines may affect considerably more people than previously suspected--even more than the NCHS research showed. In a survey of 23,000 Americans, researchers from Johns Hopkins University and the Albert Einstein College of Medicine in New York City found that 18% of the women and 6% of the men said they had migraine attacks. If the survey results can be extrapolated, that adds up to 18 million people who get migraines nationwide.
Just as migraines afflict a wide range of people, they strike in a number of ways. Some are preceded by an aura, with such spectacular effects as flashes of light, blind spots and tunnel vision. The throbbing pain, usually on one side of the head, lasts an average of 12 hours and is often accompanied by nausea and dizziness.
The underlying cause of migraines hasn’t been so easy to pinpoint. Researchers have long had to be satisfied with the theory that migraines and other headaches are brought on by dilated blood vessels in the head. A cause of that dilation has recently been traced to a part of the brainstem normally rich in the neurotransmitter serotonin. When serotonin is in short supply or the nerve receptors that respond to it malfunction, the new thinking goes, blood vessels dilate and other pain reactions cascade. Some researchers have even proposed that a genetic abnormality in serotonin transmission may be at the root of both migraine and tension headaches.
That idea gets support from recent studies of sumatriptan, which mimics serotonin by stimulating certain nerve receptors. A Dutch study of 511 subjects given sumatriptan injections during a migraine attack found that 60% to 70% got complete relief within two hours.
Sumatriptan has advantages over other painkillers. For decades, drugs related to the fungus extract ergotamine have been standard emergency-room migraine treatment. One such drug, dihydroergotamine (DHE), eases or stops pain in 75% to 80% of patients, but it has side effects such as nausea. Sumatriptan, which isn’t nauseating, awaits approval by the Food and Drug Administration.
The most excruciating type of headache is the cluster headache, which strikes in a series of brief, intense bursts. Its victims number about 1 million, mostly men. Typically the pain bores into one side of the head, often behind an eye, for anywhere from 15 minutes to two hours, up to eight times a day.
A standard remedy for cluster pain is pure oxygen. A patient inhales the gas from a pressurized canister--in the emergency room or, in some cases, at home--and in about 80% of cases the pain subsides within minutes, evidently because the oxygen constricts blood vessels in the head.
Because cluster attacks are brief, a drug must work quickly to be effective. Here again, sumatriptan shows promise. A clinical study of its effects on cluster pain led by researchers at Soder Hospital in Stockholm, Sweden, found that 29 out of 39 patients injected with sumatriptan felt relief within 15 minutes. DHE also has its supporters. According to a new study of 54 patients at the Germantown Hospital and Medical Center in Philadelphia, a DHE injection not only halted the attack in every patient but also prevented another attack for six months in 80% of cases.
The tension headache, which troubles practically everyone from time to time, was once thought to originate merely from tense facial and neck muscles. In fact, stress is the major culprit.
Familiar remedies hold. For mild, infrequent tension headaches, physicians still say the combination of an over-the-counter pain reliever (aspirin, acetaminophen or ibuprofen) and relaxation is the way to wait out the storm.
Though the precise causes of headaches remain unknown, the treatments that have been developed in recent years now promise some relief for the great majority of those afflicted.
