DEVELOPMENTAL AND/OR EPILEPTIC ENCEPHALOPATHY WITH SPIKE-WAVE ACTIVATION IN SLEEP (DEE-SWAS, EE-SWAS)

OVERVIEW

Developmental and/or epileptic encephalopathy with spike-wave activation in sleep (DEE-SWAS, EE-SWAS) is a spectrum of conditions with varied degree of cognitive, language, behavioral, and motor regression associated with marked spike-wave activation in sleep. The regression is seen within weeks of the EEG pattern. This syndrome encompasses the previous syndromes epileptic encephalopathy with continuous spike-wave in sleep and atypical childhood epilepsy with centrotemporal spikes (also previously known as pseudo-Lennox syndrome and atypical benign partial epilepsy). Landau–Kleffner syndrome is a specific subtype of EE-SWAS, where regression affects mainly language, with an acquired auditory agnosia.

NOTE EE-SWAS is used when prior development is normal whereas DEE-SWAS is used when there is pre-existing neurodevelopmental impairment before the regression occurs.

NOTE This syndrome and self-limited epilepsy with centrotemporal spikes may be considered on a spectrum, an individual child may transition from one to another over time.

Clinical context

This syndrome is characterized by seizure onset 2-12 years of age (peak 4-5 years). Both sexes are affected. Antecedent and birth history, head size and neurological examination and developmental history may be normal or may reflect the etiology (e.g. structural brain abnormality). Around 1-2 years after seizure onset there is cognitive, behavioural, psychiatric and/or motor regression or plateauing. All cognitive domains are affected including language and communication, temporo-spatial orientation, attention and social interaction. The impairments are typically severe and although some improvement occurs with time, residual deficits remain. Seizures and the EEG pattern of spike-wave activation in sleep abates typically around puberty.