Impact of etiology and lead time to treatment with first-line agents on outcome of infantile epileptic spasms syndrome-A retrospective cohort from LMIC

OBJECTIVE: To analyse the etiological spectrum, safety and effectiveness of first-line agents and developmental outcomes of children with Infantile Epileptic Spasms Syndrome (IESS) managed at a tertiary-care hospital in South India, focusing on the influence of lead time to treatment. METHODS: This retrospective cohort study included 65 children diagnosed with IESS between 2020 and 2025. Lead time to treatment was categorized as ≤1 week, 1-2, 3-8, and >8 weeks. First-line therapies included high-dose oral corticosteroids, vigabatrin, or sequential therapy. Treatment response was assessed at one and three months and developmental outcomes at follow-up. RESULTS: The median age at onset of spasms was 6 months (IQR 5,8) and the median treatment lag 4 weeks (IQR 1,12) with only 26% treated within the first week. Structural-acquired etiologies predominated (36/65; 55.3%), commonly periventricular leukomalacia (24.6%) and neonatal hypoglycaemic brain injury (13.8%). Spasm cessation occurred in 62% at one month and was sustained in 55.4% at three months, with a relapse rate of 15.4%. High-dose oral corticosteroids achieved a significantly higher one-month response than vigabatrin or sequential therapy (p = 0.006). Earlier treatment showed numerically better responses without statistical significance. Adverse effects occurred in 48%, most commonly irritability (64.5%) and weight gain (22.5%). At a mean follow-up of 19.4 months, approximately one-third of children achieved normal or borderline developmental outcomes. CONCLUSION: Structural-acquired etiologies predominated, and lead time did not significantly influence treatment response. Our findings support that high-dose oral corticosteroids appear to be an effective, practical, and reasonably safe first-line therapy for IESS in resource-limited settings.