Along with Alzheimer's disease, alcohol abuse and schizophrenia, migraine headaches are among the world's most debilitating medical disorders, according to the World Health Organization.
It may begin as a dull ache behind the eyes, or a shooting pain. It becomes more intense, causing nausea and vomiting, and a desire to crawl into a hole and pull it in after you. It's a migraine. According to Dr. Fred Sheftell, director of the New England Center for Headache, migraine sufferers are not imagining how bad it is - a migraine is a physical ailment based in the brain.
"I think we know more about what causes it than we did before," he said. "I think we know now that migraine is a disorder, which rests in the brain. It involves a variety of chemical messengers that we call neurotransmitters. I like to describe migraine as a cascade of events, a chain of events that starts in the higher centers in the brain, the cortex, winds its way down to the other brain structures and also involves changes in blood vessel activity on the surface of the brain."
For a long time it was believed that migraine was caused by dilation of blood vessels in the brain. Researchers now know that this is not always the case. Their latest findings show that migraine pain can also be generated within the brain, independent of blood vessel activity. Dr. Sheftell says many factors can trigger migraine, including hormones.
"The prevalence of migraine is greater in women than men, worldwide, across all countries, at about three to one," he said. "One of the major triggers for women is their menstrual cycle. The vast majority of women with migraine will have at least one of their severe attacks around their menses. The reason for this has to do with fluctuations in estrogen levels."
Other triggers for migraine may involve diet. Probably the most common is alcohol, especially red wine. Changes in weather, seasons, or time zones also may cause migraine. Dr. Walter Stewart of Johns Hopkins University says some migraine sufferers have what's known as chronic daily headache.
"That is a form of headache where, for the most part, migraine sufferers go from less frequent headaches to headaches that occur every day or nearly every day," he said. "It's almost as though a switch has been turned on and that pain experience is on every day. That is quite disabling."
Dr. Stewart, an epidemiologist, estimates that two to four percent of the population has chronic daily headaches and many can't hold a job or function in society because their pain is so disabling.
"The chronic daily headache experience can come and go," he said. "The phases occur for long stretches, months at a time, or years. They pose for us one of the greatest challenges in medical care. As that condition persists it certainly does wear them down psychologically. Over time, if it is not managed, they acquire other kinds of problems, psychiatric problems that would go with any sort of chronic pain condition."
The best remedy now available is a class of drugs called triptan, which block pain messages to the brain. Triptan can quickly end migraine attacks that otherwise may last up to two or three days. And Dr. Sheftell of the New England Center for Headache, says there are other promising approaches.
"Anti-epileptic compounds have recently been used more and more in treating migraine because part of migraine involves extraordinary excitability of the brain," he said. "There has been some recent work with botulin, which is a muscle paralyzer that shows some promise with migraine, as well."
Beside the strictly scientific research into the nature of migraine, patient advocacy groups also play an important role in helping migraine sufferers cope with their pain. Dr. Sheftell chairs the World Headache Alliance, which brings together representatives of these groups from more than thirty countries.
"Our job there is to increase the profile of migraine as being a serious and potentially disabling neurological disorder and to disseminate information to patients about what is available for treatment," he said.
The ultimate goal of researchers like Fred Sheftell and Walter Stewart is to relieve the painful burden of migraine in the millions people around the world who suffer from this common affliction.