Word: braine
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...much is happening all at once during a migraine that it has been hard to pinpoint what sets off the trigeminal nerve. Some scientists are focusing on a wave of electrical activity that spreads across the brain just before a migraine and triggers the aura--the shimmering light show experienced by 1 in 5 migraine patients. Others wonder wheth-er there is some kind of migraine generator buried deep within the brain stem. Even when researchers think they know the order in which different parts of the brain turn on during an attack, they can't always be sure...
What seems clear, however, is that the brain of a migraineur (as sufferers are called) is primed to overreact to all sorts of stimuli that most people can easily tolerate. "The brain receives input from a wide variety of triggers--stress, hormones, falling barometric pressure, food, drink, sleep disturbances," says Dr.David Buchholz, a neurologist at the Johns Hopkins University School of Medicine in Baltimore, Md. "Each of us has hisown stack of triggers and his own personal threshold at which the migraine mechanism activates. The higher the trigger level climbs above the threshold, the more fully activated the migraine system...
...this view, people who are prone to migraine have a low threshold for activating the trigeminal nerve. Those who suffer only an occasional tension-type headache have a much higher threshold. Persistent treatment of acute attacks and prevention of additional ones may reset the brain's threshold point at a higher level...
Researchers are exploring the possibility that migraine sufferers are not just hypersensitive to various triggers but that their brains have lost some of their natural ability to suppress pain signals. To find out more, scientists are studying a part of the brain called the periaqueductal gray matter, which, says Dr. Welch in Kansas City, "switches off the pain response so that you can focus on the fight to survive. It's the reason why if you have a cut that you don't remember getting, it doesn't start to hurt until you actually look...
Each time a migraine occurs, Welch and others have found, the periaqueductal gray matter fills with oxygen, which triggers chemical reactions that deposit iron in that section of the brain. As the iron builds up, the brain's ability to block out pain decreases. That may explain why many migraineurs become more sensitive to pain with each episode...