Language Performance and Disruption of Brain Connectivity in Children with Epilepsy

Abstract

Abstract Objective To explore the correlation between brain connectivity and language difficulties in children with epilepsy. We hypothesize that the epileptic cortex (where seizures arise) becomes hyperconnected to left frontal and temporal language regions thus suppressing connectivity between language regions. We expect that connectivity is associated with language performance. Method Right-handed children with Self-Limited Epilepsy with Centrotemporal Spikes (SeLECTS) recruited from a specialty clinic, and typically developing age and sex-matched controls (63 children, 9.3+/−2 years, 37% female) recruited from the community completed a language task (verb generation) and a resting task while undergoing an electroencephalogram. Phonological awareness was measured with the CTOPP-2. Connectivity between four regions – left frontal & temporal language regions and bilateral motor regions (epileptic cortices) – was measured using the weighted Phase Lag Index. We tested for group differences in connectivity in either task and for associations between connectivity and phonological awareness. Results SeLECTS had higher left frontal to left temporal connectivity than controls during verb generation (group difference = 0.07, 95% CI 0.02–0.11, p = 0.003) but not at rest. Right motor to left temporal connectivity was elevated in SeLECTS during verb generation (difference = 0.04, 95% CI 0.01–0.07, p = 0.008) and rest (difference = 0.03, 95% CI 0.01–0.05, p = 0.001). Higher right motor to left temporal (−55.8, 95% CI -81.5 to −30.1, p < 0.0001) connectivity during verb generation was associated with poorer phonological awareness in SeLECTS but not controls. Resting connectivity was not associated with phonological awareness in either group. Conclusions Hyperconnectivity may contribute to language difficulties and electroencephalogram may be a biomarker for phonological awareness in children with epilepsy.