What Are the Symptoms?
Aura symptoms usually develop over a period of 5 to 20 minutes and resolve in less than an hour. Most common symptoms are visual symptoms, experienced by 99% of affected people, but any symptom may occur:
Bright, dynamic visual symptoms
- Photopsia - unformed flashes of light
- Teichopsia - a slowly-expanding area of visual loss with a shimmering, jagged border
- Scotoma - partial loss of sight or a “blind spot” that is often crescent-shaped
- Visual distortion
- Hemianopsia - blindness over half the field of vision
Visual symptoms are typically bright and shimmering — even a blind spot may have such a border.
- Neurosensory symptoms, such as numbness, tingling, or pins and needles that begin in the fingers, then spread up the arm
- Mild weakness in the limbs
- Rare total amnesia, with memory intact after the attack
- Speech disturbances
What Causes It?
Aura symptoms are thought to occur when a wave of abnormal electrical activity spreads through the brain, causing certain neural areas to become temporarily silent. If this abnormal wave affects occipital brain areas, visual aura symptoms may occur without a headache.
How Is It Diagnosed?
Migraine without headache can resemble other serious conditions, so it is important to have a physician rule out potential causes such as transient ischemic attack (TIA) or retinal disease.
A typical visual aura grows and moves across the field of vision. On the other hand, TIA symptoms are usually briefer, do not move and spread across the visual field, and generally result in the dimming of vision. Retinal diseases tend to cause symptoms in one eye only that may linger for an extended time.
How Is It Treated?
An isolated aura migraine, without headache, typically does not require acute treatment, as symptoms tend to resolve fairly quickly. Some treatments may be given to shorten more prolonged aura symptoms, including isoproterenol, an inhaled beta agonist, or rapid-acting nonsteroidal anti-inflammatory drugs (NSAIDs) like naproxen or meclofenamate.
Is It Preventable?
A good first step to preventing silent migraine as well as other forms of migraine is to track migraine triggers (foods, beverages, medications, smoking, and so on) in a journal, and capture when migraines occur, how long they last, and any activity underway when they appear. It’s then important to avoid documented migraine triggers. Getting regular exercise, practicing stress management, and following a regular healthy sleep schedule may also help.