Efficacy of the ketogenic diet in neurometabolic disorders

Introduction: The ketogenic diet (KD) is a high-fat, low-carbohydrate diet, producing a state of chronic ketosis. KD results in significant changes of the energy metabolism. Glucose as fuel source is replaced by fatty-acids and ketones. Especially for the neurons of the brain ketones become the main fuel. Results: Based on the metabolic pathways affected by the KD, the by-pass effect of ketones as alternative fuel is shown for the glucose transporter protein (GLUT1) deficiency, the pyruvate dehydrogenase (PDH) deficiency and complex I deficiency of the respiratory chain. Based on our own experience and a review of the literature a survey is given concerning the efficacy of the KD in the neurometabolic disorders mentioned before. For each of these disorders the effect of the KD on the clinical course (eg. seizures, mental development, survival) as metabolism, especially lactate (tissue monitoring with subcutaneous microdialysis) is demonstrated. A focus will be the presentation of the effects of KD in the complex I deficiency of the respiratory chain. Conclusion: For disorders of the cerebral energy metabolism as GLUT1 deficiency, PDH deficiency and complex I deficiency of the respiratory chain KD is an effective therapy.