Childhood absence epilepsy (CAE), is one of the most frequent pediatric epilepsy syndromes. CAE is an idiopathic generalized epilepsy that occurs in otherwise normal children. The only seizure type at the time of diagnosis is the typical absence seizure. CAE is a well-known pediatric epilepsy syndrome affecting 10–17% of all children with epilepsy. It was previously known as pyknolepsy. The word pyknolepsy originates from the Greek piknoz (picnós), which means recurrent or grouped. The usual age of onset of CAE is between 4 and 10 years, with peak between 5 and 7 years.The typical absence seizure has a sudden onset of altered awareness and ends also abruptly. Electroencephalogram demonstrate characteristic "typical 3Hz spike-wave" generalized rhythmic discharges that begin and end abruptly. Prognosis is generally good with fair rates of response to treatment and with most patients growing out of their absencese. However, learning difficulties and seizure occurrence rates remain higher than the general population even after several years. When typical absence seizures start the age of 8– 9 years old when the absence seizures are infrequent or when the absence seizures are observed in a patient that had experienced a generalized tonic-clonic seizure, a diagnosis of juvenile absence epilepsy should be considered. Signs and symptoms
CAE is characterized by the presence of absence seizures. The absence seizures are usually brief (about 4 to 30 seconds) but occur frequently, usually around a dozen per day but sometimes even hundreds of times per day.
They involve abrupt impairment of consciousness with loss of awareness and responsiveness, behavioral arrest, and arrest of the activity that may vary from complete arrest to continuing the activity with an altered status. Other seizure features include starring, eyelid movement or eye-opening and pallor. Mild automatisms and mild movements at the beginning of the seizures are frequent, but major motor involvement, as atonic falls, early in the course of the disease excludes this diagnosis.The International League Against Epilepsy commission defined absence seizure as “of sudden onset, interruption of ongoing activities, staring, possible upwards version of eyes with few seconds duration, associated with symmetrical 2–4 Hz, mainly 3 Hz spike-wave complexes, normal background activity. Absence seizure was divided into two subgroups (Penry et al. 1975), first with consciousness impairment, and others were associated with the other clinical component, namely clonic, atonic, tonic, autonomic, and with automatisms. Though CAE usually occurs in children with normal neurodevelopment and are sensitive to antiepileptic treatments children with CAE have a risk of academic failure and high rates of attention deficits. Neuropsychological impairment
Neuropsychological impairment in children with CAE is frequent and includes executive dysfunction, attention problems, learning disabilities, and language problems. These problems even persist after seizures are treated. Monitoring with validated cognition scales should be performed. Many existing data illustrate that children with CAE have an average IQ but present subtle cognitive difficulties. In cases with lower IQ, significant social difficulties can be often seen.