visual migraine aura

Visual migraine aura is a neurological symptom experienced by some migraine sufferers, occurring in about 30% of patients. It typically involves visual disturbances that develop over several minutes and can last up to an hour. These auras have a positive component, such as flashing lights, and a negative component, like a blind spot in vision. This experience generally expands and moves across the visual field. While often followed by a headache, some individuals experience aura without head pain, a condition known as "silent migraine". The underlying cause is believed to be cortical spreading depression, a slow migration of abnormal neural activity across the brain's surface.12