Purpose: ACTH is currently the standard first-line therapy for new-onset infantile spasms, but it has significant side effects. We hypothesized the ketogenic diet (KD), previously reported as beneficial for intractable infantile spasms, would have similar efficacy, but better tolerability than ACTH when used first-line.
Methods: We conducted a retrospective chart review of all infants started on the KD (n = 13) and high-dose ACTH (n = 20) for new-onset infantile spasms at our institution since 1996.
Results: Infants were spasm-free in 8 of 13 (62%) infants treated with the KD within 1 month, compared to 18 of 20 (90%) treated initially with ACTH, p = 0.06. When effective, median time to spasm freedom was similar between ACTH and the KD (4.0 vs. 6.5 days, p = 0.18). Those treated with ACTH were more likely to have a normal EEG at 1 month (53% vs. 9%, p = 0.02), however, use of the KD led to EEG normalization within 2–5 months in all eight who became spasm-free. In the five children in whom the KD was unsuccessful, four became spasm-free subsequently with ACTH or topiramate immediately. Side effects (31% vs. 80%, p = 0.006) and relapse rate after initial success (12.5% vs. 33%, p = 0.23) were lower with the KD.
Discussion: In this retrospective study, the KD stopped spasms in nearly two-thirds of cases, and had fewer side effects and relapses than ACTH. ACTH normalized the EEG more rapidly, however. Further prospective study of the KD as, with a 2-week time limit if unsuccesful, first-line therapy for infantile spasms is warranted.