Aura Before an Epileptic Seizure

Auras are now called "focal aware seizures"

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Some people have an aura before they have a seizure—a sensation that may alert them to what's about to happen. An epileptic aura is a distinct perception—either visual, motor, sensory, or psychological—that you feel around the time a seizure occurs. Although an aura may signal a seizure only seconds before it occurs, an aura and a seizure may be separated by as much as an hour. Since auras occur prior to a seizure, they may be considered a form of a warning sign that a seizure is about to occur.

Auras are different than prodromal symptoms, which can occur hours and even days prior to a seizure, and often include emotional symptoms such as mood changes, irritability, and difficulty concentrating. Unlike prodromal symptoms, an aura is actually part of the seizure—the beginning of seizure activity.

The Cause of Auras

An aura is actually a simple partial or focal seizure, the first discharges that take place in a seizure, so the causes are essentially the cause of the seizure in the first place. The type of aura can give clues, however, to the region of the brain in which the seizure begins. 

Sometimes auras occur alone and do not proceed on to anything more. In these cases, the aura was the seizure. In fact, the International League Against Epilepsy changed the term "aura" to "focal aware seizure." This indicates that the person having it is aware, as well as that it is, indeed, its own seizure.

Types of Auras

There are several different types of auras that may occur prior to a seizure or by themselves as the seizure itself. These can also be broken down into sensory auras, in which only a sensation is present, and experiential auras which are more complex. For example, a hearing-related aura may be sensory alone, such as hearing a ringing or buzzing, or it can be experiential, such as hearing sounds and voices.

Auras vary considerably from person to person but are usually consistent—almost the same from seizure to seizure—for the person experiencing it. Some auras are easy for people to describe, such as zig-zag lines, while others are much more difficult to explain, such as a feeling of being separated from the body. Types of auras include:

  • Vision (visual): Visual auras can be simple, such as seeing bright flashes of light, dark spots, or tunnel vision, or they can be complex or experiential, such as blindness, visual hallucinations, illusions, and distorted scenery like macropsia, where everything surrounding you seems larger than normal.
  • Smell (olfactory): Certain smells may be experienced with an aura, often unpleasant.
  • Hearing (auditory): Like visual auras, hearing auras can be simple, such as hearing a ringing or buzzing, or complex (experiential), like hearing distorted sounds or voices speaking.
  • Somatosensory: These auras involve sensation and can be quite varied, including tingling sensations, a feeling of moving even while you're sitting still, or a need to move.
  • Taste (gustatory): Abnormal tastes or tastes that are present without eating food may occur, such as metallic tastes and more.
  • Abdominal: Nausea or a feeling of stomach pressure or upset is a fairly common aura with temporal lobe seizures.
  • Motor: Repeated movements of a limb or weakness may occur.
  • Autonomic: Auras such as cold shivers and goosebumps may occur as autonomic auras.
  • Psychic: These auras can be very dramatic and may include a sudden sense of fear, a sense of impending doom, deja vu experiences (the feeling that what's currently happening happened in the past), and the like. 

Types of Seizures in Which Auras May Occur

Auras are not experienced with all types of seizures. They occur frequently with partial seizures, either simple or complex, and in partial seizures with secondary generalization.

Since simple and complex partial seizures are the most common forms of seizures, auras are quite common. These seizures, in contrast to generalized "grand mal" seizures, include electrical discharge that involves one area of the brain. Auras occur in 80 percent of people with complex partial seizures (temporal lobe epilepsy).

Auras prior to generalized seizures are likely more common than previously thought. In a recent study, researchers asked open-ended questions of those who had generalized seizures. Roughly a fourth of people answered these questions, which essentially asked, "Have you had an aura?" When asking closed-ended questions, for example, asking specific questions about aura symptoms, that number increased to 64 percent of people with generalized seizures who had experienced an aura.

Importance of Auras

While auras can be helpful in warning you that you're about to have a seizure and you need to be in a safe place, they can also help healthcare providers pinpoint the area of the brain where the seizure is originating.

Types of Auras and Seizure Location in the Brain

Auras often point to the location of a seizure based on the type of symptoms. Examples of these include:

  • Occipital lobe seizures with an aura of visual changes on the other side (contralateral side)
  • "Automatisms," such as lip smacking with temporal lobe seizures
  • Somatosensory auras (touch and sensation) with seizures involving the somatosensory cortex of the brain, and motor (movement) auras involving the motor cortex (parietal lobe)
  • Psychic and head rolling auras with frontal lobe seizures

Auras as a Warning for Seizures

Since auras occur prior to a seizure, it's thought that they may play a protective role allowing people to get to a safe place before the rest of their seizure occurs. The concern over driving has been studied to some degree with some studies suggesting that people who have consistent auras should be able to drive more safely than those who do not have auras. In fact, in 1994 the American Academy of Neurology made a recommendation that people who have these consistent (and also prolonged) seizures should not have to be banned from driving as long as those who do not have auras. Unfortunately, it was recently found that people with uncontrolled seizures who experienced auras did not have fewer car accidents than those who didn't experience the warning of an aura.

Auras Without Seizures

As noted above, when an aura precedes a seizure, it's usually considered to be part of the seizure—the beginning of seizure activity. So when an aura occurs without a seizure, a seizure still occurred; the aura was the seizure, a simple partial seizure, or, as it's now called, a focal aware seizure. 

Aura Duration

Auras can usually be measured in seconds. In some very rare instances, they can last longer, in which case they actually represent partial status epilepticus.

Coping With Epilepsy

If you experience auras with epilepsy, you're not alone. Not only do auras occur in the majority of people with the most common form of seizures, but statistics tell us that epilepsy is very common. In other words, even though you may see a lot of pink ribbons out there, seizure disorders are more common than breast cancer. Epilepsy can be hereditary, so you may have family members who know what you're going through, but there's also a large online community of people coping with the disease that you can access 24/7.

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