Juvenile absence epilepsy is a genetically determined generalized epilepsy syndrome with a peak onset at 9 to 13 years of age. It manifests with severe and frequent absence seizures. The majority of patients also have generalized tonic-clonic seizures, and a few also have sporadic myoclonic jerks. EEG shows classical generalized 3 Hz spike-and-slow-wave discharges. Response to appropriate pharmacological treatment is usually excellent, but relapses are common on drug withdrawal. Appropriate antiseizure treatments include sodium valproate, ethosuximide, lamotrigine, and possibly levetiracetam. Other antiseizure medications, such as carbamazepine, eslicarbazepine, lacosamide, oxcarbazepine, phenytoin, tiagabine, and vigabatrin, are contraindicated. In this article, the author details clinical, electroencephalographic, genetic, and management aspects of juvenile absence epilepsy and emphasizes how its differential diagnosis compares with other focal and generalized epileptic syndromes.
| || |
• Juvenile absence epilepsy is a genetically determined generalized epilepsy characterized by (a) typical absence seizures occurring frequently with significant impairment of consciousness and (b) generalized tonic-clonic seizures. Myoclonic jerks may also occur; these are mild and with no particular circadian distribution.
| || |
• The differential diagnosis includes other syndromes manifesting with absence seizures, such as childhood absence epilepsy, juvenile myoclonic epilepsy, generalized epilepsy with phantom absences, and absence seizures associated with glucose transporter 1 (GLUT-1) deficiency syndrome.
| || |
• Most of the available evidence is inconclusive regarding the evolution and prognosis of juvenile absence epilepsy. The prevailing view is that most patients with juvenile absence epilepsy usually respond well to appropriate pharmacological treatment, but this may need to be lifelong.
Historical note and terminology
The first description of juvenile absence epilepsy was probably by Janz and Christian in 1957, when they categorized patients with non-pyknoleptic absences (36). Doose and associates found that peak age at onset in children with absence seizures congregated into 3 groups: children 4 to 8 years of age with childhood absence epilepsy (female preponderance); children younger than 4 years of age; and children 10 to 12 years of age (no sex differences) and with cycloleptic (in cycling clusters) or spanioleptic (spanios=rare) absences and frequently generalized tonic-clonic seizures (15).
The Commission on Classification and Terminology of the International League Against Epilepsy (ILAE) proposed in 1981 that typical absences of “idiopathic” generalized epilepsies be differentiated from atypical absences of symptomatic generalized epilepsies (10). However, all epilepsies with typical absence seizures remained for a long time clustered in the group of "petit mal" and were considered a form of "centrencephalic epilepsy." In 1989, the ILAE Commission proposed to distinguish 3 syndromes of “idiopathic” generalized epilepsy: childhood absence epilepsy, juvenile absence epilepsy, and juvenile myoclonic epilepsy (11). Subsequently, the ILAE Task Force proposed that juvenile absence epilepsy be classified as a syndrome of adolescence (20; 06) under the category of “genetic generalized epilepsies” along with childhood absence epilepsy, juvenile myoclonic epilepsy, and generalized tonic-clonic seizures alone (57).