Epilepsy and neurodevelopmental disorders of language

Neurodevelopmental disorders of language are increasingly appreciated as part of the phenotype of childhood-onset epilepsy. Here I review studies of the prevalence and prognosis of language impairment in new-onset childhood epilepsy and provide an update of new genetic discoveries that shed light on molecular pathways common to epilepsy and language impairment.

Three recent papers describe the cognitive and language phenotype of children with new-onset epilepsy and their discrepancy with controls over a 2-3-year period of follow-up. A new study examines the question of pleiotropic effects acting on both electro-encephalographic (EEG) abnormalities and speech sound disorder in rolandic epilepsy families - another study questions the rationale for EEG recording in patients with specific language impairment (SLI) - whereas two studies examine the effect of anti-epileptic drug treatment on speech and language. Two MRI studies indicate the neural basis for language impairment in epilepsy. Three new copy number variant hotspots are reported linking epilepsy and speech or language impairment; and the links between two known genes for developmental verbal dyspraxia, FOXP2 and SRPX2, begin to be elucidated.

Comprehensive neuropsychological and speech pathology assessment need to be factored into the initial evaluation and continued monitoring of children with new-onset epilepsy. EEG recording remains of unknown utility in children with SLI or speech sound disorder (SSD) who do not have epilepsy. Some anti-epileptic drugs may worsen SSD. As the molecular pathways for speech continue to be elucidated, future genetic imaging studies will show how genetic variants map onto to altered structural and connectivity patterns, which could be used as biomarkers for interventions.