Predictors of language skills in the long term after pediatric epilepsy surgery

The objective of this study was to evaluate language skills in a heterogeneous cohort of patients who underwent or were considered for epilepsy surgery in childhood 4-11years earlier. The few existing studies that have evaluated cognitive function in the long term after surgery have examined intelligence and memory.

Participants were 97 patients, of whom 61 underwent surgery. They completed standardized tests of picture naming, vocabulary, letter fluency, semantic fluency and intelligence at baseline and, on average, 7years later.

Among all patient groups, scores across language tasks were similar at baseline and follow-up. Language skills were largely independent of surgical status but were associated with seizure control. Seizure freedom and/or a longer proportion of life without seizures were associated with higher scores across all language tasks at follow-up. However, few patients showed meaningful improvements or deterioration at the individual level. Older age at epilepsy onset, higher IQ, and higher baseline scores were associated with higher follow-up scores on all language tasks. Localization and lateralization of epileptogenic foci and language lateralization were associated with higher scores on some language tasks at follow-up. Most of these variables were also predictive of change in scores over time on some of the language tasks.

Language skills largely remained similar at baseline and follow-up. Seizure freedom was associated with a modest advantage at the group level, and no significant change at the individual level, suggesting an abnormal neural substrate or epileptic activity prior to seizure control may hinder the long-term capacity for improvement, even in the absence of seizure activity.