Word: painful
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Dates: during 2000-2009
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...back as the 1600s, the prominent English physician Thomas Willis suggested that headaches are caused by a rapid increase in the flow of blood to the brain. He theorized that the suddenly bulging blood vessels put pressure on nearby nerves and that these in turn trigger the pain. A variation on Willis' idea became the favored explanation for the cause of migraines. (An important network of blood vessels at the base of the brain bears Willis' name...
...endings deeper into the brain led researchers to the trigeminal nerve, a complex network of nerve fibers that ferries sensory signals from the face, jaws and top of the forehead to the brain. During the course of a migraine, scientists discovered, the trigeminal nerve practically floods the brain with pain signals. The more researchers learn about the trigeminal nerve, the more they believe that it is involved in all types of primary headaches, including tension and cluster headaches. The differences in the headache types seem to stem from what activates the trigeminal nerve and how it responds...
...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--and the more pain...
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...