People who don't have migraines often think not only of a headache being part of a migraine, but also of the migraine aura. Many people think a migraine can't occur without an aura. Sadly, even some doctors believe this misconception.
The aura is the second potential phase of a migraine attack. (You can read more about the phases and their potential symptoms in Anatomy of a migraine.) The aura phase is experienced by a minority of migraineurs, only about 20 to 25%, and most people who experience aura, don't experience it with every migraine attack. Most migraineurs who are diagnosed with migraine with aura (MWA) are also diagnosed with migraine without aura (MWOA). Most people think about visual symptoms when they think about aura, but there can also be aura symptoms that are not visual.
To better understand migraine aura, let's take a look at some of the potential symptoms:
- Scotoma, an area of decreased or lost vision. Some people describe scotoma as being like having tiny blank spots in their vision. Some say it looks like tiny snowflakes.
- Wavy lines. Some have described their vision being similar to how things appear on a hot day through the heat rising from the pavement of streets.
- Phosphenes: brief flashes of light that streak across the visual field.
- Blurry vision.
- Unilateral blindness. This occurs only in retinal migraine.
- Aphasia: loss or impairment of the power to use or comprehend words.
- Auditory hallucinations: hearing sounds that aren't really there.
- Olfactory hallucinations: smelling odors that aren't really there.
- Allodynia: hypersensitivity to feel and touch.
- Paresthesia: often described as numbness or as a prickly, stinging, or burning feeling.
- Decrease in or loss of hearing.
- Reduced sensation.
- Motor weakness. This must be distinguished from numbness or tingling and is a symptom of hemiplegic migraine only.
- Hemiplegia (unilateral paralysis). This also is a symptom of hemiplegic migraine only.
A rare aura:
Alice in Wonderland Syndrome is a rare form if migraine aura. The most distinctive symptom of "Alice in Wonderland" syndrome is this type of metamorphosia, a distortion of body image and perspective, which migraineurs know is not real. "Alice in Wonderland" syndrome can occur at any age, but is more commonly experienced by children. You can read more about this in Alice in Wonderland Syndrome - The Basics.
Summary and comments:
Migraine aura can present with a wide range of symptoms that can affect not only vision, but other senses as well. In most cases, the symptoms are short-lived and resolve by the end of the aura or the end of the headache phase. In some cases, especially with hemiplegic migraine, some neurological symptoms can persist for months, but this is not common.
Migraine aura symptoms can be confusing and sometimes frightening. Some of these symptoms can be especially frightening because they can also be cause by other issues including stroke.
If you experience aura symptoms (or other symptoms) that are new for you, please be sure to contact your doctor to confirm that they are part of your migraine and not from stroke or another medical issue. This is critical for your safety.
Evans, Randolph W. & Rolak, Loren A. (2004) Expert Opinion. Headache, The Journal of Head and Face Pain 44 (6), 624-625. doi: 10.1111/j.1526-4610.2004.446013.x
Evans, Randolph W.; Mathew, Ninan T. "Handbook of Headache," Second Edition. Lippincott Williams & Wilkins. 2005.
Young, William B., M.D.; Silberstein, Stephen D., M.D. "Migraine and Other Headaches." American Academy of Neurology Press. 2004.
Robert, Teri. "Living Well with Migraine Disease and Headaches." HarperCollins. 2005.