Ketogenic diet in adolescents and adults with epilepsy

Purpose The ketogenic diet is an alternative treatment for patients with refractory epilepsy. Most studies to date report dietary response in children. There are limited data evaluating the efficacy of the ketogenic diet in adults. This is a report of the long-term outcome in a largely adult population of patients treated with the ketogenic diet for epilepsy. Method Twenty-nine adult and adolescent patients (mean age 32 years, range 11-51) were initiated on the ketogenic diet and followed until diet discontinuation. Clinical response and adverse effects were noted during the duration of the diet. Results Fifty-two percent of patients had a significant reduction in seizure frequency on the ketogenic diet, including 45% with ≥50% reduction in seizure frequency. Thirty-one percent had no improvement, seven percent were unable to successfully initiate the diet, and 10% had a >50% increase in seizure frequency. The diet was continued for a mean of 9 months (range 0.13-35 months), with five patients completing ≥23 months. There was a trend toward better response and better tolerability/longer duration in patients with symptomatic generalized epilepsy. The diet was generally well-tolerated, but undesired weight loss and constipation were the most frequent adverse effects. Conclusion The ketogenic diet can be used safely in the adult and adolescent population, with a response rate similar to those seen in children. Patient with symptomatic generalized epilepsy may be particularly good candidates for this type of dietary treatment.