A sudden migraine attack in a research subject undergoing brainscan has led to a serendipitous proof of a theory of the origin of the throbbing headache. Known as the "spreading depression" theory, it ascribes the excruciating pain to reduced blood supply throughout the brain and not just to the site of pain, as commonly believed.
Scientists at the University of California, Los Angeles, noticed in the subject a 30 per cent drop in blood supply at the site of the headache. The decrease in blood flow then spread across the surface of the brain. They believe the results could lead to new treatments for migraine.