Some individuals have an aura before a seizure episode. An aura is a distinct perception, either motor, visual, sensory or psychological that is felt at the same time a seizure arises.
Even though an aura might indicate a seizure only seconds before it arises, an aura and seizure might be separated by an hour. Since auras manifest before a seizure, it is considered as warning that one is about to occur.
What are the causes?
An aura is generally a simple partial seizure which are the initial discharges that occur in a seizure, thus it is caused by the root of the seizure initially. The form of aura might provide a clue to the site of the brain where the seizure starts.
In some cases, auras manifest alone and does not progress to anything more. In such instances, the aura was the seizure.
What are the types of auras?
There are various types of auras that can manifest before a seizure. The auras can be categorized as sensory where only a sensation is present and experimental which is more complex.
The auras vary from one individual to another but generally consistent. Some auras are easy to describe while others find it hard to explain.
- Visual – seeing bright flashes of light, tunnel vision or dark spots. If experimental, it includes visual hallucinations, blindness, distorted scenery and illusions.
- Smell or olfactory – certain smells might be present that are often unpleasant
- Somatosensory – tingling sensations, feeling of movement while still or a need to move
- Auditory or hearing – hearing a ringing or buzzing sound but can also be complex such as hearing voices speaking or distorted sounds
- Taste or gustatory – unusual tastes or the presence of taste without eating
- Motor – repeated motions of a limb or weakness
- Abdominal – pressure in the stomach, nausea or stomach upset
- Autonomic – cold shivers and goosebumps
- Psychic – sudden sense of fear, feeling of impending doom or déjà vu experiences
The auras can be measures in seconds. It is rare for one to last longer where they represent partial status epilepticus.