Efficacy of the ketogenic diet in Lennox-Gastaut syndrome: A retrospective review of one institution's experience and summary of the literature

Aim To determine the efficacy of the ketogenic diet for children with Lennox-Gastaut syndrome (LGS) at our institution and in the literature. Method The records of children with LGS initiated on the ketogenic diet at our institution from 1994 to 2010 were reviewed. Inclusion criteria included the presence of ≤2.5Hz spike-and-wave complexes on electroencephalogram, multiple seizure types including tonic, atonic, or atypical absence, developmental delay, and age under 1year. We additionally reviewed the literature for cases of LGS treated with the ketogenic diet and their outcomes. Results Seventy-one children (41 males, 30 females, median age 3y 6mo, range 18mo-18y), with LGS were initiated on the ketogenic diet. Using an intent-to-treat analysis, after 6months, 36 (51%) achieved more than 50% seizure reduction, 16 (23%) experienced more than 90% seizure reduction, and 1 (1%) achieved seizure freedom. Results were similar after 12months. Age, sex, side effects, valproate use, and history of infantile spasms were not predictive of more than 90% seizure reduction. In the literature, 88 of 189 (47%) children with LGS had more than 50% seizure reduction after 3 to 36months of ketogenic diet treatment. Interpretation The ketogenic diet is efficacious in the treatment of LGS, with approximately one-half of children responding at 12months.