2. Migraine Is the Result of a Hypersensitive Brain
Most physicians—including experts in headache medicine—used to believe that migraine was caused by cranial blood vessels expanding and contracting, Rothrock says. “It was thought that migraine-associated constriction of blood vessels reduced blood flow to the eye or brain, producing aura, and that a compensatory dilation of the blood vessels caused the throbbing, sickening head pain.”
But it turns out that migraine is actually “a genetic condition that, as with epilepsy, produces a hypersensitive brain,” Rothrock says. He notes that researchers at Harvard recently reported evidence indicating that electrical events originating in the brain itself may provoke activation of the receptors for head pain that are located “downstream,” within the meninges that cover the brain.
“It appears that a migraine attack may originate within the visual cortex of the brain,” Rothrock says, “with activity generated at that site serving to promote the trigeminal nerve to release neuropeptides that in turn induce blood vessels located in the meninges to leak pro-inflammatory proteins, which activate and further sensitize head pain receptors, which consequently send a message back to the brain that ‘there’s pain out here.’ This to-and-fro, self-reinforcing process—brain to meninges/meninges to brain—builds and builds until finally it wears itself out, or one administers a therapy that blocks the signaling of head pain.”