Infantile epileptic spasm syndrome: predictors of short- and long-term outcomes

TL;DR

This study identifies early treatment response and underlying causes as key factors affecting outcomes in children with infantile epileptic spasm syndrome.

Contribution

The study reveals that early treatment response and etiology are strong predictors of seizure and developmental outcomes in IESS.

Findings

Early treatment response at 3 and 6 months predicts favorable seizure and developmental outcomes in IESS.

Genetic and structural etiologies increase the risk of developing epileptic encephalopathy.

Poor early responders are more likely to develop epileptic encephalopathy.

Abstract

Infantile epileptic spasm syndrome (IESS) has significant impact on affected children that affects their future seizure control and neurodevelopmental outcomes. The aim of this study is to identify potential short- and long-term predictors of outcomes in children diagnosed IESS.

This retrospective study evaluated outcomes of seizure control and developmental status in a historical cohort of 60 children with IESS. The predictor variables included: age, treatment regimen, and early treatment response at 14 days, 3 and 6 months on the measured outcomes.

Among the 60 children in the cohort, 75% had identified etiologies: Genetic (40%), Structural (35%), and unknown causes (25%). Treatment interventions included either vigabatrin monotherapy (58.33%) or hormonal therapy with or without vigabatrin (41.67%). Clinical response at 3 and 6 months significantly correlated with good seizure control (p = 0.008 and p = 0.007, respectively) and favorable developmental outcome (p < 0.001) at last follow-up. Logistic regression showed that treatment response at 3 months increased the odds of good seizure control by 7.21 times (95%CI = 1.93–26.91, p = 0.003), after adjusting for age, treatment regimen, and etiology. Genetic and structural etiologies were significantly associated with a higher likelihood of developing epileptic encephalopathy (EE), with odds ratios of 11.79 (95% CI = 2.04–68.06, p = 0.006) for genetic etiology and 10.21 (95% CI = 1.75–59.65, p = 0.010) for structural etiology.

Early treatment response at 3 and 6 months strongly predicts favorable seizure and developmental outcomes in IESS, with poor responders at these time points more likely to develop EE. Genetic and structural etiologies significantly influence EE risk, emphasizing the need for early identification, sustained treatment monitoring, and potential targeted interventions for high-risk subgroups.