Childhood absence epilepsy (CAE)

This is a common epilepsy syndrome starting in early childhood. These seizures can happen in many different epilepsy syndromes occurring in childhood and adolescence. This information refers specifically to the syndrome of childhood absence epilepsy.

Symptoms

The seizures of childhood absence epilepsy usually start between the ages of four to nine years of age, and happen slightly more often in girls than boys. They can also happen many times a day, from 20 up to several hundreds.

A typical absence seizure consists of a sudden loss of awareness. The child will suddenly stop their activities and stare blankly into space. They will be unresponsive to voice. The seizure is sometimes associated with repetitive, purposeless movements of the mouth or eyes (called automatisms). This can include eyelid flickering or fluttering and lip smacking.

A seizure usually last between five and 20 seconds and usually stops as suddenly as it starts, with the child resuming their normal activities.

Absence seizures tend to happen more commonly when the child is bored, sitting quietly or when they are tired or unwell. Conversely, they happen less often when the child is engaged with an activity that they enjoy.

Children with CAE usually develop normally, although uncontrolled absence seizures may impact on the child’s ability to learn at school. Sometimes a child’s concentration or memory is said to be very poor before the diagnosis of the childhood absence epilepsy is made.

Diagnosis

The diagnosis is usually suggested by the history. The doctor may ask the child to hyperventilate (over-breathe) for three to four minutes while counting out loud. This will trigger an absence seizure in over 90 per cent of children with typical CAE, and is important in making the diagnosis.

An electroencephalogram (EEG) test is useful in confirming the diagnosis. The EEG may also be used to monitor response to treatment. No other tests such as a brain scan are required in typical CAE.

Treatment

CAE usually responds very well to treatment. The drugs of choice are sodium valproate (Epilim), ethosuximide (Zarontin) and lamotrigine (Lamictal). Occasionally a combination of two of these medications may be required to control absences.

Prognosis (Outlook)

The outlook of typical CAE is excellent, with the majority of children becoming seizure free as they pass through puberty.

About 70 per cent of children with CAE will have their absence seizures completely controlled with one or two antiepileptic drugs.

Approximately 10 per cent of children will develop other seizure types in adolescence, usually generalised tonic-clonic seizures. However these seizures are infrequent and tend to respond to treatment.

Some children with CAE may also develop other seizure types such as myoclonic seizures (sudden, brief jerks). When looked at in more detail these children will almost certainly not have CAE but instead have a different epilepsy syndrome such as juvenile absence epilepsy or juvenile myoclonic epilepsy.

Because this page is written by an epilepsy healthcare professional and not by Epilepsy Action, it falls outside the requirements of the Information Standard.