Absence seizure

Definition

An absence seizure is the term for a type of seizure involving staring spells. This type of seizure is a brief (usually less than 15 seconds) disturbance of brain function due to abnormal electrical activity in the brain.

Causes

Seizures result from overactivity in the brain. Absence seizures occur most often in people under age 20, usually in children ages 6 to 12.

In some cases, the seizures are triggered by flashing lights or when the person breathes faster and more deeply than usual (hyperventilates).

They may occur with other types of seizures, such as generalized tonic-clonic seizures (grand mal seizures), twitches or jerks (myoclonus), or sudden loss of muscle strength (atonic seizures).

Symptoms

Most absence seizures last only a few seconds. They often involve staring episodes. The episodes may:

Unexplained difficulties in school and learning difficulties may be the first sign of absence seizures.

During the seizure, the person may:

The person usually does not fall during the seizure.

Right after the seizure, the person is usually:

Specific symptoms of typical absence seizures may include:

Some absence seizures begin slower and last longer. These are called atypical absence seizures. Symptoms are similar to regular absence seizures, but muscle activity changes may be more noticeable.

Exams and Tests

The doctor will perform a physical exam. This will include a detailed look at the brain and nervous system.

An EEG (electroencephalogram) will be done to check the electrical activity in the brain. People with seizures often have abnormal electrical activity seen on this test. In some cases, the test shows the area in the brain where the seizures start. The brain may appear normal after a seizure or between seizures.

Blood tests may also be ordered to check for other health problems that may be causing the seizures.

Head CT or MRI scan may be done to find the cause and location of the problem in the brain.

Treatment

Treatment for absence seizures includes medicines, changes in lifestyle for adults and children, such as activity and diet, and sometimes surgery. Your doctor can tell you more about these options.


Review Date: 2/27/2018
Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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