Specialty: Pediatric Neurology 

Keywords: infantile spasms, hemispherectomy, epilepsy 

Background: Infantile spasms (IS) is a severe epileptic syndrome associated with poor developmental outcomes. For children unresponsive to anti-seizure medications, hemispherectomy (surgical resection of the diseased brain hemisphere) offers a potential cure but carries substantial risks. Prior studies suggest that surgical outcomes are variable, yet there is insufficient data on which factors predict likelihood of experiencing epilepsy relapse. 

Objective: This study aims to identify predictors of seizure relapse after hemispherectomy in patients with infantile spasms. 

Methods: A retrospective cohort of children with infantile spasms who underwent hemispherectomy was analyzed using a multi-center database. For the sub-cohort of UCLA patients, data on demographics, clinical features, electrophysiology, neuroimaging, and surgery were extracted from electronic medical records and reviewed. Predictors of epilepsy relapse were assessed using multivariable logistic regression. Key covariates included contralateral neuroimaging/EEG abnormalities, duration of epileptic spasms, age at surgery, and etiology of infantile spasms. 

Results: Among 331 children with IS who underwent surgical resection, 94 (28.4%) experienced epilepsy relapse. Logistic regression analysis revealed that presence of contralateral neuroimaging/EEG abnormalities was significantly associated with relapse (OR 3.2, 95% CI 2.1–4.8, p < 0.001). Duration of epileptic spasms was also predictive of relapse, with a 1.5-fold increase in risk for every additional year from infantile spasms onset to first surgery (HR 1.5, 95% CI 1.2–1.8, p < 0.001). Other significant predictors included younger age at surgery (HR 0.8, 95% CI 0.7–0.9, p = 0.002) and structural etiology (OR 2.5, 95% CI 1.5–4.1, p < 0.01). 

Conclusions: Children with neuroimaging abnormalities contralateral to the hemispherectomy side and those with longer durations of epileptic spasms prior to surgery exhibit a significantly higher risk of epilepsy relapse. These findings highlight the importance of early surgical intervention and comprehensive preoperative neuroimaging evaluation, to optimize long-term outcomes in children with refractory infantile spasms.