Long-term evolution of neuropsychological competences in encephalopathy with status epilepticus during sleep: a variable prognosis

PurposeThe aim of this study was to evaluate the long-term cognitive outcome in children with continuous spikes and waves during slow wave sleep (CSWS syndrome).MethodsWe reviewed the neuropsychological tests of 25 children diagnosed with CSWS between 1987 and 2010 and with a mean follow-up of 13.5years.Key FindingsCognitive performances worsened during CSWS in virtually all patients. Seven patients (28%) with nonlesional epilepsy had a positive outcome; three patients (12%) showed persistence of motor deficit without involvement of cognitive functions; and seven patients (28%) who presented a long duration of CSWS (mean=28.1 months) had a negative cognitive outcome. In 6 patients (24%) with structural or metabolic disorders before CSWS onset cognitive outcomes did not change; 2 patients (8%) had a negative outcome irrespective of the duration or presence of other neurologic disorders before CSWS onset. Forty-four percent of children with CSWS demonstrated permanent cognitive impairment.SignificanceThe long-term outcome of CSWS syndrome is variable and seems to depend on treatment response, disease duration, and underlying etiology.