Migraine Auras are transient visual symptoms characterized by geometric shapes (like jagged lines), colors, and movement (like vibrations, waves etc). They usually start as a small disturbance, then enlarge over 10-30 minutes, then resolve. They can occur in any part of the vision. They often are immediately followed by a migraine headache, but they also may occur without a headache.
What causes an Aura?
The cause may be vascular changes in the brain which lead to spontaneous discharge of neurons in the brain. The triggers of migraine — caffeine, red wine, cheeses, sleep loss, hormonal changes, etc — can trigger an Aura. Rarely, they are caused by a Transient Ischemic Attack (TIA or mini-stroke), focal seizure, or a structural problem in the brain like an arteriovenous malformation. Occasionally eye disease, such as a retinal vein occlusion, can cause similar symtoms, so a dilated eye exam is necessary.
What treatments are available?
Treatment is similar to migraine therapy.
Because they are self-limited, often no treatment is required if no headaches follow. Because they are considered a minor risk factor for a stroke, vascular risk factors should be treated.
The North American Neuro-Ophthalmology Society publishes a web site with good patient information on this condition.