An observational study on outcome of hemispherotomy in children with refractory epilepsy.

Introduction: The current study aimed to evaluate the clinical characteristics and outcome of hemispherotomy in children with refractory hemispherical epilepsy.

Methods: Retrospective analysis of data in twenty one children aged ≤12 years who underwent hemispherotomy and had at least two years post surgery follow-up was performed. Sixteen children underwent Delalande's vertical para-sagittal hemispherotomy (VPH), while lateral peri-insular functional hemispherotomy was performed in the rest.

Results & Discussion: The average age of onset for epilepsy in the study population was 2.9 ± 2.4 years; the average duration of epilepsy was 4.0 ± 2.9 years. The mean age at surgery of the study population was 6.8 ± 2.8 years. Six (28.5%) children were girls. Gliosis due to presumed childhood infarct was most common etiology, observed in 13 (62.0%) of the children, followed by Rasmussen's encephalitis in six (28.5%). There was no significant difference between the surgery groups for the reported acute post operative seizures (APOS) (20.0% vs. 25.0%; p = 1.000). At last follow up 90.5% patients were seizure free; there was no difference between the groups for seizure freedom (60.0% vs. 87.5%; p = 0.228). When analyzed for outcome between the etiologies, seizure freedom was similar for gliosis due to infarct (76.9%), Rassmussens encephalitis (83.3%) and malformations of cortical development (MCD) (100.0%). Moreover, improved quality of life in epilepsy (QOLIE) scores was observed in 80.0% of the lateral peri-insular functional hemispherotomy group and 87.5% children in VPH group at the last follow-up.

Conclusion: Gliosis due to presumed childhood infarct was the leading cause of medically refractory epilepsy caused by hemispheric lesions in the current study. Encouragingly, hemispherotomy offers seizure freedom (in 90.5% patients) and improvement in QOLIE scores at two years follow up.