What causes migraine auras?
Migraine auras seem to be caused by a wave of electrical nerve impulses (excitation) travelling slowly across part of your brain. This is followed by a long period of underactivity in this area. If you have auras, this underactivity results in reduced action in the part of your body controlled by that section of your brain. The back of your brain, which controls your eyes, is most often affected. This explains why your eyes see only part of what they are looking at. When the areas of your brain that are affected are the ones that control how your body feels, you may feel numb in one part of your body.
