Atypical language impairment in two siblings: relationship with electrical status epilepticus during slow wave sleep.

We report the case of a young girl who presented severe learning disabilities in oral and written language related to a continuous spike-waves during slow sleep (CSWS) syndrome. A sleep EEG recording obtained in her younger brother, who presented a clinical pattern suggesting developmental dysphasia, also showed a CSWS syndrome. These two clinical cases underscore the need to look for this syndrome in the siblings of an affected child when learning difficulties appear in a child who previously had normal psychomotor development.