Therapeutic effects of the ketogenic diet in children with Lennox-Gastaut syndrome

•The ketogenic diet can effectively control seizures in children with LGS.•The ketogenic diet can improve abnormal EEG background activity and reduce IEDs.•Early improved EEG background is a predictor of clinical outcome in LGS.

ObjectiveThe aim of this study was to evaluate the efficacy of the ketogenic diet (KD) on the clinical and electroencephalographic (EEG) features of Lennox-Gastaut syndrome (LGS) and explore the relationships between EEG changes and clinical efficacy.MethodsWe retrospectively studied 47 patients with LGS who accepted KD therapy between May 2011 and May 2015. Clinical efficacy and EEG features such as background activity, abnormal interictal epileptic discharges (IEDs) and the discharge location were evaluated prior to and at 3 and 6 months after therapy. Responders were defined as ≥50% seizure reduction.ResultsAt 3 months of treatment, 23 patients (48.9%) had ≥50% seizure reduction. Seven patients (14.9%) discontinued treatment between 3 and 6 months because of lack of efficacy or inability to adhere to the diet. At 6 months of treatment, 4 patients (10%) were seizure free, 5 (12.5%) had ≥90% seizure reduction, 12 (30%) had a reduction of 50-89%, and 19 (47.5%) had <50% reduction. Patients with improved EEG background and reduced IEDs had an improved seizure reduction rate compared with patients without change in EEG background or IEDs (p < 0.01).ConclusionsThe results show that the KD is effective in LGS. It can control seizures and improve EEG abnormalities. Early improvement in the EEG background and a reduction in IEDs may be predictors of a patient's response to diet.