Epilepsy and language development: the continuous spike-waves during slow sleep syndrome
Continuous spike-waves during slow sleep syndrome (CSWSS) is a rare epileptic syndrome occurring in children, which is characterized by the association of epilepsy, neuropsychological disorders, and abnormal paroxysmal electroencephalographic (EEG) discharges activated by sleep. Language can be affected but, to date, language disorders and their long-term outcome have been documented only rarely. Description of language impairment in patients with the CSWSS. We performed a detailed language testing in 10 right-handed children and adolescents with the CSWSS. Their pragmatic performance was compared to that of a control population of 36 children aged 6-10 years. Patients with CSWSS had lower scores in tests measuring their lexical, morphosyntactic, and pragmatic skills compared to controls. Comprehension remains unaffected. In addition, language impairment was found to be just as severe in patients in remission as those still in an active phase. We found severe language impairments in lexical and syntactic skills. The language profile is different from that observed in the Landau-Kleffner syndrome. Moreover patients in remission and those in an active phase of the CSWSS have the same language impairment profiles. This confirms the poor long-term neuropsychological prognosis. Our results raise points about the relationship between epileptic activity and language development. This pilot study underscores the need to assess language, and especially pragmatic skills, and to study long-term outcome in such childhood epileptic syndromes.