Oxygen deprivation part of the problem

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."

...a few studies have found that people who get auras with their migraines are at increased risk for vascular problems like heart attack and stroke