Prospective study of the efficacy of a ketogenic diet in 20 patients with Dravet syndrome

Purpose: We evaluated the efficacy and tolerability of the ketogenic diet (KD) on generalised convulsions and status epilepticus (SE) in patients with Dravet syndrome (DS). Methods: Patients with DS having >= 2 generalised convulsions/month despite drug treatment were included in this study and placed on a KD for 6 months. From 3 months before (baseline) to 6 months after KD initiation, caregivers recorded patients' seizure activity, antiepileptic drug use, and adverse events. The KD efficacy was determined by examining the frequency and duration of seizures at 3 and 6 months vs. baseline. Responders were defined as individuals whose generalised convulsions decreased in frequency by >= 50% vs. baseline. Seizures lasting >= 5 min and SE were specifically evaluated. Patients' cognition was also assessed at 3 and 6 months via questionnaire. Results: Twenty patients continued the KD for at least 3 months. Of the 17 responders identified at month 3, seizures decreased by 50-89% and 90-99% in nine and two patients, respectively; six patients were seizure free. The KD was ineffective in three patients, who discontinued the diet. By month 6, seizures decreased by 50-89% and 90-99% in six and one patient(s), respectively; 10 patients were seizure free. The frequency of other seizure types also improved. During all 6 months, neither generalised convulsions lasting >= 5 min nor SE was detected in the 17 responders. The KD also improved patients' cognition. Conclusion: The KD is a good treatment option for medically intractable epilepsy.