Abstracts

Rationale: In 2005 we started a team at the National Centre for Epilepsy using the ketogenic diet (KD) in a systematic way, in the treatment of refractory epilepsy. The aim of this study was to investigate if increased experience in the professional team affected the results. Methods: Patients There were 38 patients between 7 months and 14 years old. They had tried 1-16 antiepileptic drugs (mean 8.3). Fifteen children had cerebral palsy. There were 24 children with severe or profound mental retardation (MR), 12 with mild or moderate MR and two without MR. The patients started KD between February 2005 and December 2007. There were 34 patients with generalized or multifocal epilepsy, one had Dravet syndrome one had localized symptomatic epilepsy, one had migrating epilepsy of infancy, and one had GLUT1 deficiency. Introduction of the diet The KD was gradually introduced without fasting until the patient became seizure free or had reached a 4:1 ketogenic ratio. The ketogenic ratio was not increased to 4:1 in some patients due to development of ketoacidosis. Modification of treatment Gradual modification to diet and treatment regimes included earlier treatment of ketoacidosis, better hydration of the patients and a more persistent increase in the ketogenic ratio after ketoacidosis. There was a more thorough communication with the parents concerning side effects and the importance of dietary compliance over time and a more accurate calculation of caloric requirement. Potassium citrate was introduced as nephrolithiasis prophylaxis. Analysis The efficacy of the diet was analysed retrospectively over a 7 months period with binary logistic regression analysis. The relative proportion with >50% seizure reduction was evaluated depending on the number of months that had elapsed since the beginning of the program. Results: Seven patients became seizure free. Eleven had >90% and 15 had > 50% seizure reduction. Regression analysis showed that the relative proportion with more than 50% seizure reduction increase about 20% for each month the diet was used in the clinic (p=0.015.) None of the first 18 patients had > 50% seizure reduction! The group without severe mental retardation had a significant higher effect (p=0.034). There was no significant difference in effect of the diet depending on age. There was a significantly reduction in the frequency of ketoacidosis in patients treated with potassium citrate as nephrolithiasis prophylaxis. Conclusions: This study suggests that improved education, confidence and familiarity with the KD by parents and the professional team lead to better response and compliance. In our study children with less severe or no MR as a sign of less severe cerebral dysfunction responded better to the diet than children with severe or profound MR. Nephrolithiasis prophylaxis with potassium citrate gave a significant reduction of initial ketoacidosis, which made it possible to increase the ketogenic ratio faster. Potassium citrate might also decrease the number of patients who have to stop treatment due to ketoacidosis.