Management of Drug-resistant Epilepsy in Infants and Children: a Real-life Study of the Use of the Ketogenic Diet in France and the KetoCal® Range in Its Maintenance

Inclusion Criteria: * Infants from 5 months and children up to 17 years of age (maximum 18 years minus 1 day). * With drug-resistant epilepsy according to ILAE (International League Against Epilepsy) criteria: persistence of epileptic seizures after failure of two appropriate antiepileptic drugs tried consecutively or in well-tolerated combination. * Indication for CR by a physician. * Parents (or legal guardians) able to set up and follow the diet, assessed during a joint doctor-dietician consultation. * Written authorization from one (or both) parents or the child's legal representative to collect personal information about their child. * Affiliation of the infant/child with the social security system. Exclusion Criteria: * Contraindication to ketogenic diet at initial assessment. * Children already on a ketogenic diet. * Parenteral nutrition. * Concurrent prescription of other foodstuffs intended for special medical purposes (DADFMS) such as KetoVie or Keyo. * Protected legal representative (under legal protection, or deprived of liberty by judicial or administrative decision). * Legal representative not covered by a social security scheme. * Legal representative unable to understand study protocol. Ancillary study eligibility criteria : * Patients included in the study. * Continued on the ketogenic diet for at least 2 months. * Having consented to participate in the ancillary study.