Cognitive phenotypes in childhood idiopathic epilepsies

•Cognition is variably affected in the idiopathic childhood epilepsies.•This variability was quantitated by identifying discrete cognitive phenotypes.•Identified phenotypes ranged from cognitively intact (44%) to very impaired (12%).•The cognitive phenotypes had no association with epilepsy syndrome.•They were associated with brain structure, parent IQ, and developmental history.

ObjectiveThe objective of this study was to identify cognitive phenotypes in children with new-onset focal and generalized idiopathic epilepsies and determine their relationship with epilepsy syndrome, brain structure, neurodevelopmental history, and family characteristics.MethodsOne hundred thirty-eight children with new-onset epilepsy and 95 controls (age: 8-18) underwent neuropsychological, clinical, and quantitative MR evaluations. Control participants' neuropsychological data were subjected to confirmatory factor analysis and then resultant factor scores were applied to participants with epilepsy and subjected to latent class analysis. Identified cognitive phenotypes were examined in relation to epilepsy syndrome, quantitative neuroimaging, and familial and neurodevelopmental variables.ResultsConfirmatory factor analysis identified five cognitive factors (verbal, perceptual, speed, attention, executive), and latent class analysis identified three clusters of participants with epilepsy: 1) average and similar to controls, 2) mild impairment across multiple cognitive domains, and 3) impairment across all domains with severe attentional impairment, representing 44%, 44%, and 12% of the epilepsy sample, respectively. Cognitive phenotype membership was not associated with epilepsy syndrome but was associated with increasing abnormalities in brain structure, parental IQ, and features of early developmental history.SignificanceCognitive phenotypes are present in idiopathic childhood epilepsies that are unassociated with traditional epilepsy syndromes but are associated with measures of brain structure, family history, and neurodevelopmental features.