Aura (symptom)
| Aura | |
|---|---|
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| Artist's depiction of zig-zag lines appearing as part of a migraine aura phenomenon | |
| Classification and external resources | |
| Specialty | Neurology |
| ICD-10 | G43.1 |
| ICD-9-CM | 346.0 |
An aura is a perceptual disturbance experienced by some with migraines or seizures before either the headache or seizure begins. It often manifests as the perception of a strange light, an unpleasant smell, or confusing thoughts or experiences. Some people experience aura without a subsequent migraine or seizure (see silent migraine). Auras vary by individual experience; some people experience smells, lights, or hallucinations. Less known symptoms of the eye include disturbances, where the eyes roll in the back of the head caused by photosensitivity. A sufferer of this type of aura may experience tearfulness of the eyes and uncontrollable sensations of light followed by reduced symptoms after approximately 20 minutes; it is the rarest type of aura.
When occurring, auras allow people who have epilepsy time to prevent injury to themselves and/or others. The time between the appearance of the aura and the migraine lasts from a few seconds up to an hour. The aura can stay with a migraine sufferer for the duration of the migraine; depending on the type of aura, it can leave the person disoriented and confused. It is not uncommon for migraine sufferers to experience more than one type of aura during the migraine. Most people who have auras have the same type of aura every time.
Auras can also be confused with sudden onset of panic, panic attacks or anxiety attacks creating difficulties in diagnosis. The differential diagnosis of patients who experience symptoms of paresthesias, derealization, dizziness, chest pain, tremors, and palpitations can be quite challenging.
An epileptic aura is the consequence of the activation of functional cortex by abnormal, unilateral, and brief neuronal discharge. In addition to being a warning sign to an upcoming seizure, the nature of an aura can give insight into the localization and lateralization of the seizure or migraine.
Not everyone experiences an aura with a seizure, but the most common auras include motor, somatosensory, visual, and auditory symptoms. The activation in the brain during an aura can spread through multiple regions continuously or discontinuously, on the same side or to both sides.
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