What is it?
Some people who get migraines also experience a variety of mostly visual sensations that come before or accompany the pain of a migraine attack — a condition called migraine with aura.
Most often, a migraine with aura is characterized by visual disturbances such as flashes of light, zigzagging patterns or even blind spots. However, a migraine with aura may also be accompanied by other sensations, such as numbness or tingling in parts of your body and speech problems.
Pain relievers and prescription medications can treat a migraine with aura. But, preventive medications and self-care measures, including avoiding migraine triggers, may help you prevent a migraine with aura.
Symptoms
Visual disturbances are the most common feature of migraine aura. Signs and symptoms may include:
- Shimmering spots or stars
- Zigzag lines that gradually float across your field of vision
- Loss of vision
- Blind spots (scotomas)
- Flashes of light
These types of visual disturbances tend to start in the center of your visual field and move outward, or spread.
Other types of sensations may accompany your visual disturbances, including:
- Feelings of numbness, typically felt as tingling in an extremity or on your face
- Confusion
- Difficulty with speech or language
A migraine aura usually occurs within an hour before head pain begins and generally lasts from 10 to 30 minutes before disappearing. Rarely, aura may occur with no headache.
Along with the aura, other signs and symptoms of migraine with aura include:
- Severe head pain, often one-sided
- Sensitivity to light
- Nausea and vomiting
- Painful skin (cutaneous allodynia) — as many as two out of three people with migraine also experience painful skin sensations during normal activities, such as brushing hair, wearing contacts or wearing tight clothes
Causes
The cause of a migraine with aura isn't clearly understood. However, it's believed that a visual aura is like an electrical or chemical wave that moves across the part of your brain that processes visual signals (visual cortex). As the wave spreads, it may cause these visual hallucinations.
A number of factors may trigger migraine, including:
- Stress
- Hormonal changes
- Sensory stimuli — such as bright lights or unusual smells
- Fatigue
- Changes in the environment
- Head trauma
- Hunger
- Certain medications
- Certain foods, especially those with preservatives
Risk factors
The following factors may increase your risk of migraine with or without aura:
- Family history. Migraines are more common in people with a family history of migraines.
- Sex. Women are three times as likely to have migraines as men are.
- Hormonal changes in women. Migraine may worsen or change during menstruation, pregnancy or menopause. Migraine may also worsen if you take birth control pills or hormone replacement therapy.
Complications
People who have migraine with aura are at a slightly higher risk of stroke. Women with migraines have an even higher risk of stroke if they smoke, take birth control pills or have high blood pressure.
Although the link between stroke and migraine isn't clearly understood, it could be connected to changes in the blood vessels or blood flow in your brain.
Diagnosis
If you have typical migraines or a family history of migraine with aura, your doctor will likely diagnose the condition on the basis of your medical history and a physical exam.
But if your headaches are severe or sudden, your aura isn't followed by head pain, or the visual disturbances affect only one eye, your doctor may recommend certain tests to rule out more serious conditions, such as transient ischemic attack — a temporary decrease in blood supply to part of your brain — that could be causing your symptoms.
Your doctor may recommend:
- An eye (ophthalmologic) examination. During this exam, your doctor will use an instrument the size of a small flashlight (ophthalmoscope) to project a beam of light into your eye to examine the back of your eyeball (fundoscopy).
- Computerized tomography (CT). This X-ray technique produces detailed images of your internal organs, including your brain.
- Magnetic resonance imaging (MRI). This diagnostic imaging procedure produces images of your internal organs, including your brain.
Your doctor may also refer you to a doctor who specializes in nervous system disorders (neurologist) to rule out brain conditions that could be causing your symptoms.
References
http://www.webmd.com/migraines-headaches/what-is-a-migraine-with-aura
http://www.migraine.ie/health-professionals-and-migraine/the-migraine-attack/migraine-aura/
http://my.clevelandclinic.org/health/diseases_conditions/hic_Migraine_Headaches
http://www.thelancet.com/journals/laneur/article/PIIS1474442209701358/abstract
https://americanmigrainefoundation.org/living-with-migraines/types-of-headachemigraine/migraine-and-aura/