Cognitive outcome of pediatric epilepsy surgery across ages and different types of surgeries: A monocentric 1-year follow-up study in 306 patients of school age

Objective: The neuropsychological outcome of pediatric epilepsy surgery has been reported before, but only few studies compared different major types of surgery in differentially located epilepsies. Methods: Neuropsychological performance of 306 children and adolescents (ages 6-17 years) were assessed before and one year after epilepsy surgery. Individual impairments, changes into and out of impairment, as well as intraindividually meaningful positive or negative changes were examined. Regression analyses addressed the effects of site, side, pathology, type of surgery, seizure outcome, and drug change on the cognitive and behavioral domains. Results: Preoperatively 85% of the patients had cognitive impairments in at least one domain, 71% had behavioral problems. Postoperatively the number of impaired patients dropped considerably: 21-50% of the patients changed from impaired to unimpaired, individually significant gains were registered in 16-42%. Seizure freedom was achieved in 81% of all patients. The number of antiepileptic drugs decreased significantly. Seizure freedom, a younger age at evaluation, a later age at onset, a lower antiepileptic drug load, and less baseline damage predict better cognitive and behavioral outcomes. Gender, pathology, localization, and lateralization had little or no impact. Conclusion: Differentially located and lateralized epilepsies hardly differed in cognition and behavior indicating nonspecific developmental rather than domain specific impairments. Childhood epilepsy surgery is very successful and the functional improvements one year after surgery confirm the general relevance of baseline damage, mental reserve capacities, functional plasticity, the preservation of functional tissues and the functional release due to seizure freedom and drug load reduction.