Abstracts

Rationale: ACTH is the standard first-line therapy for new-onset infantile spasms, but it has significant side effects. We hypothesized the ketogenic diet (KD) would have similar efficacy for this condition, but better tolerability.Methods: We conducted a retrospective, case-cohort study of all infants started on either KD (n=13) or ACTH (n=20) for new-onset infantile spasms at our institution since 1996. Infants started on KD were fasted 24-48 hours, calories gradually increased, and outcomes evaluated after 1 month. After that point, the KD was typically continued only if the child was spasm-free. ACTH was given intramuscularly initially at 150 units/m2/day followed by weekly tapering doses over one month.Results: ACTH was more likely than KD to result in a spasm-free outcome (18/20 (90%) vs. 8/13 (62%), p=0.06) and normal EEG (53% vs. 10%, p=0.04) at 1 month. Outcomes for both ACTH and KD were similar at 3-6 months. When effective, ACTH had a slightly shorter median time to spasm freedom (4.0 vs. 6.5 days, p=0.18). Side effects (23% vs. 80%, p=0.002) and relapse rate after initial success (12.5% vs. 33%, p=0.23) were lower with the KD. In the 5 children in whom the KD was unsuccessful, 4 became spasm-free subsequently with ACTH or topiramate; both of the two children who did not initially respond to ACTH became spasm-free with topiramate.Conclusions: ACTH was more likely than KD to result in spasm-freedom and EEG normalization after one month. However, the KD was effective in nearly two-thirds of cases within 2 weeks, and had fewer side effects and relapses than ACTH. Further prospective study of the KD for this novel indication is warranted.