Long-term developmental outcome after early hemispherotomy for hemimegalencephaly in infants with epileptic encephalopathy

Abstract

This study aimed to identify the effect of early hemispherotomy on development in a consecutive series of 12 infants with hemimegalencephaly (HME) demonstrating epileptic encephalopathy. Mean age at onset was 20.4days (range, 1–140), mean age at surgery was 4.3months (range, 2–9), and mean follow-up time was 78.8months (range, 36–121). Eleven patients had a history of early infantile epileptic encephalopathy. Vertical parasagittal hemispherotomy was performed without mortality or severe morbidities. At follow-up, seizure freedom was obtained in 8 patients (66.7%), who showed significantly higher postoperative developmental quotient (DQ) (mean, 31.3; range, 7–61) than those with seizures (mean, 5.5; range, 3–8) (p=0.02). Within the seizure-free group, postoperative DQ correlated with preoperative seizure duration (r=−0.811, p=0.01). Our results showed that shorter seizure duration during early infancy could provide better postoperative DQ in infants with HME and epileptic encephalopathy.