Safe and effective use of the ketogenic diet in children with epilepsy and mitochondrial respiratory chain complex defects

PURPOSE: To evaluate the clinical efficacy and safety of the ketogenic diet (KD) for patients with intractable childhood epilepsy and mitochondrial respiratory chain (RC) complex defects. METHODS: A retrospective analysis evaluated outcomes in 14 children with intractable epilepsy and RC complex defects who were treated with the classic KD involving a 4:1 lipid to nonlipid ratio (% by weight), but without an initial fast and fluid restriction. Outcome measures included seizure frequency, electroencephalography (EEG) findings, the number of antiepileptic drugs, and adverse reactions. RESULTS: Of the 14 patients, 9 had Complex I defects, 1 had a Complex II defect, 3 had Complex IV defects, and 1 had combined Complex I and IV defects. Two patients with Complex IV defects showed clinical progress compatible with the Leigh disease. The epileptic diagnoses were as follows: 5 patients were diagnosed with infantile spasms, 4 with the Lennox-Gastaut syndrome, 1 with the Landau-Kleffner syndrome, 1 with nonspecific generalized seizure disorder, and 3 with partial seizure disorder. The study found that 7 patients became seizure-free after commencing the KD, three of whom successfully completed the diet without relapse. One patient with a greater than 90% seizure reduction, and 2 patients with seizure reductions between 50% and 90%, remained on the diet. Four patients, including two diagnosed with the Leigh disease, did not show any favorable responses to the diet or ceased the diet due to complications. CONCLUSIONS: The KD was a safe and effective therapy for seizures in children with intractable epilepsy and RC complex defects.