Short- and long-term seizure-free outcomes of dietary treatment in infants according to etiology

Purpose: It is important to determine whether specific etiology is more effective to dietary treatment so that the diet can be started earlier for infants. We evaluated etiology-specific, seizure-free outcomes of dietary treatment in infants <1 year of age. Methods: We conducted a 10-year, retrospective, longitudinal observational study of 115 infants treated with ketogenic diet (KD) or modified Atkins diet (MAD). Results: Most patients (70%) received classical KD; 30% received MAD. During follow-up, 90%, 73%, and 61% of the patients remained on the diet at 3, 6, and 12 months, respectively. Seizure-free outcomes were reported in 50%, 44%, and 50% of the patients at 3, 6, and 12 months, respectively. Long-term seizure-free outcomes over 12 months were reported in 43 (74%) of 58 infants who were seizure-free at 3 months. Etiologies were mostly symptomatic (structural brain abnormalities, genetic, or metabolic) in 83 (72%) of 115 patients. According to underlying etiology, long-term seizure-free outcomes were observed in 14 (33%) of 42 patients with structural brain abnormalities, 7 (33%) of 21 with genetic etiologies, 7 (35%) of 20 with metabolic etiologies, and 15 (47%) of 32 with unknown etiologies. There were no etiology-based differences with respect to long-term seizure-free outcomes (P = 0.63). Conclusion: The high rate of long-term seizure-free outcomes can be predicted based on the seizure freedom at 3 months regardless of etiology. Early dietary treatment is beneficial, even in infants <1 year of age with specific symptomatic etiologies such as genetic, structural brain abnormalities, and metabolic etiology.