PURPOSE:To evaluate the long-term efficacy/tolerability of the ketogenic diet (KD) in paediatric drug-resistant epilepsies.

METHODS:Data from children who were treated between 1999 and 2008 and had continuous follow-up of at least 6 months after initiation of the KD were analysed retrospectively. Response was defined as>or = 50% seizure reduction. Treatment effects on EEG, developmental outcome and the "outcome-predictive" value of various clinical factors were also assessed.

RESULTS:50 children (22 boys; mean age 4.5 years+/-3.55) were included. Mean follow-up was 3.93+/-2.95. 50% of the patients were responders, 48% of them became seizure free. 50% were non-responders, 20% of them deteriorated. In responders, EEG background activity improved significantly (p=0.014) and a significantly lower rate of epileptic discharges (p=0.009) was seen after 6 months. In addition, neurological examination findings demonstrated significant developmental progress (p=0.038). Favourable treatment outcome was associated with a shorter disease duration (p=0.025) and generalised tonic clonic seizures (p=0.059). No further significant outcome predictors were detected. However, response was 44% in patients with infantile spasms, 62.5% in those with Dravet syndrome and 50% in Lennox-Gastaut-syndrome. Side effects occurred in 28%, but discontinuation of the KD was not required in any case. They most often observed with concomitant topiramate (p=0.001) and valproate (p=0.046).

CONCLUSION:Despite the retrospective nature of the study and the inhomogeneous patient sample, we found good long-term effects of the KD on seizure frequency, EEG and neurological development.

OBJECTIVE:The 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.

METHODS:We 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.

RESULTS:At 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%, and19 (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).

CONCLUSIONS:The 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.