Migraines Linked to Brain Artery Structure: Blood Flow Incomplete

Migraines can be debilitating for some people, adding stress and pain to their everyday life. For years, researchers have examined what might cause migraines, trying to determine the exact mechanism so that they can better treat these headaches. Now, they may have found a new clue. Scientists have discovered that the network of arteries supplying blood flow to the brain is more likely to be incomplete in people who suffer migraine. These variations in arterial anatomy lead to asymmetries in cerebral blood flow that may contribute to the process that triggers migraines.

Migraine affects an estimated 28 million people in the U.S. Although researchers once thought that migraine was caused by dilation of blood vessels in the head, now they believe it's due to abnormal neuronal signals. Yet this latest study provides another answer. It seems to show that blood vessels play a different role than previously suspected and that structural alternations of the blood supply to the brain may increase a person's susceptibility to changes in cerebral blood flow.

In order to make these findings, the scientists examined 170 patients from three groups. One group had no headaches, one group had migraine with aura and the third group had migraine without aura. The researchers then used magnetic resonance angiography in order to examine blood vessel structure. They then used a noninvasive magnetic resonance imaging method called Arterial spin labeling (ASL) in order to measure changes in cerebral blood flow.

"People with migraine actually have differences in the structure of their blood vessels--this is something you are born with," said Brett Cucchiara, the new study's lead author, in a news release. "These differences seem to be associated with changes in blood flow in the brain, and it's possible that these changes may trigger migraine, which may explain why some people, for instance, notice that dehydration triggers their headaches."

In fact, the scientists noted that the abnormalities in the blood flow they saw were most prominent in the back of the brain. Since this is where the visual cortex is located, it could explain why most common migraine auras consist of visual symptoms-l-ike spots, flashing lights or wavy lines.

The findings could help researchers better understand what triggers migraine. In addition, the research could help scientists develop better treatments for these headaches, which could help patients in the future.

The findings are published in the journal PLOS One.