What are Absence Seizures?

Absence seizures are short, sudden pauses in conscious activity that result from abnormal electrical functioning in the brain. These types of seizures are characteristic of a neurological disorder called epilepsy, and an afflicted individual can potentially have several dozen or hundreds of episodes a day. An absence seizure can last anywhere from a fraction of a second to about 15 seconds, and can lead to a lapse in concentration, unusual muscle movements, and unintentional staring. Most people who have this type of epilepsy are able to effectively manage their symptoms and minimize episodes by taking daily antiepileptic drugs.

Electrical and chemical signals are constantly flowing through the brain in a complex yet highly organized manner. When an absence seizure occurs, brain activity momentarily gets held up, and an individual suddenly stops whatever he or she was doing, such as walking or speaking. The hands, eyelids, lips may move or shake awkwardly, and the person usually cannot help but stare straight ahead. Absence seizures rarely last longer than 15 seconds, and most people have no memory of episodes.

It is often difficult for doctors to pinpoint the exact causes of a person's absence seizures. The disorder is most common in children and adolescents, probably due to the fact that electrical activity in a growing brain is more chaotic as new pathways and connections are made. In fact, most people grow out of their seizure disorders by the time they reach 25. Some studies suggest that this form of epilepsy can be inherited from one or both parents. Absence seizures may also arise as a result of drug abuse, alcohol withdrawal, head trauma, or congenital nervous system defects.

Medical attention is needed for a child or adult who experiences absence seizures. At a hospital, a patient is usually evaluated by a neurologist or epileptologist. The doctor can take a magnetic resonance imaging (MRI) scan of the brain to check for physical abnormalities and an electroencephalogram (EEG) to monitor electrical activity. MRI and EEG results are used to determine the type and severity of the patient's seizure disorder.

Doctors usually treat absence seizures by prescribing antiepileptic medications. Many of the drugs used to treat epilepsy can have negative side effects, such as liver failure or depression. Patients typically are carefully monitored for several weeks after beginning a regimen of a particular medication. As a precaution, a patient who experiences frequent absence seizures may be instructed to avoid potentially dangerous activities, such as driving a car. Most people who take medications and receive regular checkups with neurologists are able to live normal, symptom-free lives.