Seizure and developmental outcomes after hemispherectomy in children and adolescents with intractable epilepsy

The aim of this study is to describe a series of pediatric hemispherectomies, reviewing pathologic substrate, epilepsy characteristics and seizure outcome as well as developmental profiles, before and after surgery, in different domains. Seventeen patients with full pre-surgical work-up, minimum follow-up of 12 months, and at least one post-surgical neuropsychological evaluation were selected. Three had Rasmussen encephalitis (RE), five hemispheric malformations of cortical development (MCD), and nine hemispheric vascular lesions. At latest follow-up, all patients with RE and 66.7 % of those with vascular lesions are in Engel's class I; in the latter group, pre-surgical independent contralateral EEG discharges statistically correlated with a worse seizure outcome. Patients with MCD showed the worst seizure outcome. Pre-surgical language transfer to the right hemisphere was confirmed in a boy with left RE, operated on at 6 years of age. Patients with MCD and vascular lesions already showed severe global developmental delay before surgery, which persists afterwards. A linear correlation was found between earlier age at surgery and better outcome in personal-social, gross motor, and adaptive domains, in the vascular lesions group. The case with highest cognitive improvement had continuous spike and wave during sleep on pre-surgical EEG. Pathologic substrate was the main factor related with seizure outcome. In children with MCD and vascular lesions, although developmental progression is apparent, significant post-surgical improvements are restricted by the severity of pre-surgical neuropsychological disturbances and a slow maturation. Early surgery assessment is recommended to enhance the possibilities for a better quality of life in terms of seizure control, as well as better autonomy and socialization.