Background. We aimed to investigate the effectiveness of ketogenic diet (KD) in children with various types of refractory epilepsy.

Methods. A total of 91 children (49 females) aged 3 to 193 months (median, 52 months) with drug resistant epilepsy who received KD treatment for at least 12 months were enrolled in the study. Seizure frequency, adherence to diet, reason for discontinuation of KD, and adverse effects were recorded. Response was defined as ≥50% improvement in seizure frequency compared to baseline. We also searched for influences of different variables on the outcome.

Results. Intent-to-treat analysis revealed an improvement in seizure frequency for ≥50% in 73.6%, 80.2%, 75.8%, 73.6%, and 70.3% of patients at month-1, -3, -6, -9, and month-12, respectively. Overall, 32 (35.2%) patients remained seizure-free at month-12. There was no significant differences between responders and nonresponders in terms of age at onset of epilepsy, age at onset of KD, gender, or etiology. Mild hyperlipidemia was associated with a higher response rate. At the last follow-up (median: 20 months), 38 (41.8%) patients were still maintained on KD. While 15.4% of patients completed the diet with a success in seizure control, remainder discontinued KD due to lack of efficacy (23.1%), non-adharence to diet (11%), intercurrent infection (4.4%), adverse effects (3.3%), and death (1.1%).

Conclusion. Ketogenic diet treatment appears to be effective in about two-thirds of children with various types of drug-resistant epilepsy, including one-third remaining seizure free. Mild hyperlipidemia seems to be associated with a higher response rate. Discontinuation of KD is mostly due to lack of efficacy or nonadherence, and rarely side effects.

Keywords: drug-resistant epilepsy, effectiveness, ketogenic diet, tolerability