Ten-year single-center experience of the ketogenic diet: factors influencing efficacy, tolerability, and compliance
Objectives To evaluate the efficacy, tolerability, and compliance of 3 ketogenic diets, the classical ketogenic diet, medium-chain triglyceride (MCT), and modified Atkins diet. Study design A single-center, retrospective study of 48 children with intractable epilepsy receiving ketogenic diets from 2003 to 2012. Patient demographics, epilepsy history, nutritional management, and side effects were collated. Compliance and tolerability were assessed by recording reasons for diet modification and cessation. The value of potassium citrate supplementation for preventing nephrolithiasis was reviewed. Results Median age at ketogenic diet initiation was 3.8 years (IQR: 2.3-7 years). The majority had intractable epilepsy, and 33 of the 48 children (69%) had epileptic encephalopathies. Three (6%) patients became seizure free, 35 (73%) reported <50%-90% reduction, and 10 (21%) had 0%-50% reduction during a 2-year period. Diet duration or ketogenic diet type did not predict reduction in seizures (P = .381; P = .272). Constipation (n = 31, 65%) was very common. Food refusal (n = 3, 6%) and poor parental compliance (n = 5, 10%) were common reasons cited for cessation. There were lower rates of side effects for modified Atkins diet. Diet cessation was greatest for MCT; however, 3 patients on MCT ceased therapy because adequate seizure control was achieved. Nephrolithiasis was reported in 1 patient before potassium citrate was used and 2 patients noncompliant with potassium citrate supplementation developed hypercalciuria. Conclusion The 3 ketogenic diets were comparably effective in seizure control and generally well-tolerated. Potassium citrate supplementation is an effective prophylactic supplement for the prevention of nephrolithiasis.