What is Absence Epilepsy?

Absence epilepsy is a seizure disorder characterized by the occurrence of so-called “absence seizures,” where the patient stares into space for several seconds and is unaware of his or her surroundings. In around half of people with absence epilepsy, these are the only kinds of seizures experienced. Other patients can develop other types of seizures, including tonic-clonic seizures, also known as grand mal seizures. There are treatments available for absence epilepsy and other seizure disorders.

Onset of absence epilepsy usually occurs in childhood or adolescence. It can be difficult to identify in patients who only experience absence seizures; children may be mistakenly labeled as inattentive or spacey by people who do not realize that they are actually having generalized seizures, for example. Typical absence seizures last for a very short period of time and can sometimes easily be mistaken for daydreaming.

The signs of an absence seizure vary from patient to patient. Some people simply stare off into space. Others will engage in purposeless movements and may have twitches or tics. Some patients walk around aimlessly. In all cases, the patient does not respond to stimuli and will forget the seizure as soon as it is over. Because the seizures are so short, most patients don't experience a sense of lost time that might tip them off to the fact that something is wrong.

People can experience numerous seizures a day; absence epilepsy is also known as pyknolepsy, after the Greek word for “cluster,” as a reflection of the fact that the seizures tend to bunch together. The seizures can become dangerous. There is a risk that someone could fall or become injured during an absence seizure, especially if it occurs while operating heavy machinery.

Diagnosis of absence epilepsy requires a thorough examination by a neurologist. The doctor can evaluate the patient and conduct an interview to check for signs of things that could be causing the seizures, such as a head injury or an environmental exposure. An electroencephalogram can reveal characteristic wave patterns in the brain that indicate the presence of a seizure disorder.

Medications are available to treat absence epilepsy and may be recommended if a patient is also experiencing other kinds of seizures. Patients who are not interested in taking medication, or who have seizures that do not respond to medications, may find it helpful to alert coworkers, teachers, friends, and family to the fact that they have a seizure disorder.