Migraines may be doing more than causing people skull-splitting pain. Scientists have found evidence that the headaches may also be acting like tiny transient strokes, leaving parts of the brain starved for oxygen and altering the brain in significant ways.
A paper describing the work by neuroscientists at the University of Rochester Medical Center appeared online April 29 in Nature Neuroscience.
The scientists say the work makes it crucial for migraine sufferers to do everything they can to prevent their headaches. While avoiding severe pain has long been a motivating factor, the scientists say the risk of brain damage makes it imperative to prevent the headaches, by avoiding a person?s triggers for the headaches and by using medications prescribed by doctors to prevent them.
?Normally, the focus of migraine treatment is to reduce the pain. We?re saying that migraines may be causing brain damage, and that the focus should be on prevention, which will stop not only the pain but also minimize potential damage,? said Maiken Nedergaard, M.D., Ph.D., the neuroscientist who led the research team. She is a professor in the Department of Neurosurgery and a member of the Center for Aging and Developmental Biology and worked closely with Takahiro Takano, Ph.D., research assistant professor, who is first author of the paper.
By combining two recently developed imaging technologies, Nedergaard?s team was able to get an unprecedented look at the events that happen in the brain of a mouse as a migraine unfolds. The team uncovered a complex, unexpected tale of supply and demand regarding blood flow and oxygen.
In short, the team found that the brain develops a voracious demand for energy as the organ attempts to restore the delicate chemical balance that is lost in the initial throes of a phenomenon known as cortical spreading depression, which is thought to underlie many migraines.
Even though the brain?s arteries expand dramatically and make a great deal more oxygen-rich blood available to meet the demand for energy, some parts of the brain still wind up experiencing severe oxygen shortage, or hypoxia. This causes parts of brain cells? sophisticated signaling structures to disintegrate, similar to what occurs when a person has a mini-stroke, or after a severe injury, or when blood flow to the brain is completely stopped, such as during a heart attack.
?In mice, the damage from these episodes looks exactly like the damage that occurs to the brain from repeated TIAs, or transient ischemic attacks,? said Takano. ?It?s long been known that patients having a migraine attack are functionally impaired from the pain. It?s also been shown recently that with repeated migraines, a person?s cognitive abilities decrease. But actually doing damage to the brain ? that is a surprise.?