EEG anomalies, sleep modification and developmental dysphasia
The relation between severe developmental dysphasia and paroxystical anomalies was analyzed in 52 children, mean age 9 years (group I) suffering from developmental dysphasia, compared to a control group of 20 children, mean age 8 years (group II). The children of both groups were selected excluding cases with a prior history of epilepsy or neurological disease, and all had a cerebral MRI in the normal range. In group I, using the Rapin and Allen classification, we distinguished: 14 children with a syntactic-lexical syndrome and 34 children with a syntactic-phonological syndrome. Two children had verbal agnosia and two others verbal dyspraxia. The analysis of repeated standard EEGs showed: normal recordings in all the group II children and paroxystical anomalies in six of the 52 group I children. Night ambulatory sleep recordings showed such anomalies in 18 of the 34 children with a syntactic-phonologic syndrome and in 6 of the 14 children with a syntactic-lexical syndrome, but in only two of the 20 children of the control group. Paroxysmal abnormalities predominated in light sleep (stages I + II) and slow wave sleep (stages III + IV), but were rare in REM sleep. The abnormalities were diffuse or localized over the left frontotemporal area. Children with developmental dysphasia also showed an inconstant nocturnal sleep pattern with a higher incidence of awakenings during sleep significantly different from our group control. The relations between dysphasias, Landau-Kleffner syndrome, paroxystical anomalies, and sleep disorders are discussed and the results of genetic research concerning such population suffering from language disorders analyzed.