Abstracts

Infantile spasms (IS) are a severe epilepsy syndrome presenting usually within the first year of life and may lead to poor neurodevelopmental outcomes without intervention. While high-dose ACTH therapy is the standard of care, the American Academy of Neurology and Child Neurology Society have concluded there is insufficient data to recommend an optimal treatment protocol¹. This study aims to demonstrate that a treat-retreat protocol using high-dose ACTH therapy is both efficacious and safe for achieving cessation of IS without compromising neurodevelopment.

This study was conducted by retrospective chart review of all patients diagnosed with IS and treated with high-dose ACTH 150 U/m² tapered over 10 weeks at Bristol Myers Squibb Children’s Hospital between 2003 and 2019. Patients were included if they met EEG and clinical criteria for IS, and individuals treated at outside institutions were excluded. Underlying etiology, time to treatment, and presence of premorbid epilepsy were recorded. Treatment success was defined as clinical cessation of spasms and normalization or return to baseline of EEG. Patients who did not respond to initial therapy or relapsed were retreated with ACTH or given adjunctive therapy. Data was collected regarding primary and secondary treatment success, adverse outcomes, and developmental outcomes.

The query identified 25 patients who met inclusion criteria. Initial treatment with high-dose ACTH was sufficient for spasms cessation and EEG normalization in 76% of patients. Response rates were similar between patients with cryptogenic IS and those with a known etiology (75% and 78%, respectively). An additional 5 patients achieved remission after retreatment, yielding an overall success rate of 96%, higher than historical success rates of 76%². No relapses occurred in patients with a delay in treatment more than one week after onset of IS. Long-term follow-up (mean of 6.5 years) revealed development of subsequent epilepsy in 24%; only one of these patients received two rounds of therapy. There was one patient of the cohort for whom IS did not resolve. Adverse effects were mild and occurred in 52% including irritability, weight gain, and hypertension; no patients required discontinuation of therapy.

The findings of this study support the use of a high-dose ACTH treat-retreat protocol as an effective first-line strategy for IS, with a 96% overall success rate and manageable side effect profile. Results of retreatment exhibit clear improvement in initial non-responders, and relapse did not impact later remission or developmental recovery.