Efficacy and tolerability of olive oil-based ketogenic diet in children with drug-resistant epilepsy: A single center experience from Turkey.

PURPOSE: Ketogenic diet (KD) is an effective non-pharmacological treatment for drug-resistant epilepsy. The aim of this study was to investigate the efficacy, tolerability and complications of olive oil-based KD in epileptic children.

METHOD: In this single-center, prospective study, patients were followed up at 1, 3, 6 and 12 months after KD initiation. Initially, blood ketone levels were measured daily, and as needed thereafter to maintain the levels between 4 and 5 mmol/L. Patient demographics, seizure frequency, serum biochemistry, abdominal ultrasonography and adverse effects were recorded. Efficacy of KD was defined as ≥50% seizure reduction.

RESULTS: A total of 389 patients with drug-resistant epilepsy receiving KD from 2012 to 2016 were included. One hundred patients (25.7%) stopped the diet for different reasons in the first year, and 369, 314, 225 and 160 patients have been receiving KD treatment for 1, 3, 6 and 12 months, respectively. At 1, 3, 6 and 12th months, 65.8% (243/369), 74.7% (235/314), 70.6% (159/225) and 83.1% (133/160) of the patients were responders, respectively. None of the children had an increased seizure-frequency. Hyperlipidemia (50.8%), selenium deficiency (26.9%), constipation (26.2%), sleep disturbances (20.0%), nephrolithiasis (3.0%), hyperuricemia (3.0) and hepatic side effects (2.6%) were the most common complications of KD. Previous adrenocorticotropic hormone (ACTH) use due to epileptic encephalopathy and presence of constipation at baseline or during KD treatment were found the predictors of treatment efficacy.

CONCLUSION: KD is an effective and well-tolerated treatment option for patients with drug-resistant epilepsy. Previous history of ACTH use and constipation during KD treatment are important factors that affect the efficacy of KD treatment.