[Typical absence seizure: epidemiological and clinical characteristics and outcome]

To analyze the epidemiological and clinical characteristics and outcome of absence epilepsy in the pediatric age group with the aim of facilitating its diagnosis in clinical practice.

Information on epidemiological and clinical characteristics, complementary investigations, and outcome was collected from the medical records of 51 children with absence epilepsy. The criteria defined by the International League Against Epilepsy (ILAE) were used in the diagnosis.

Fifty-one percent of the patients had simple absence seizures and 49% had complex absence seizures. A total of 70.6% of the patients were school-aged children and the prevalence was greater among girls (72.5%). The mean age at onset was 7.5 +/- 2.7 years. In 80%, there were multiple seizures per day with a mean duration of 12 seconds. School performance was impaired in 19.6%. Ictal electroencephalogram showed generalized 3 Hz spike and slow wave complexes in 84.3%. Hyperventilation was positive in 98%, and intermittent photic stimulation was positive in 15.7%. The seizures were controlled by sodium valproate (mean dosage: 26 mg/kg/day) in 84.3% of the patients. In 43 patients antiepileptic drugs were withdrawn (mean duration: 3.3 +/- 0.6 years) but 3 patients relapsed.

Typical absences are a common type of epilepsy in the pediatric age group and generally begin in school-aged children. Absences may be difficult to detect and can impair learning. Treatment response is excellent. Nevertheless, because absences may be the first manifestation of severe forms of epilepsy syndromes, strict follow-up of these patients is essential.