P 256. Use of Ketogenic Diets in patients with Epilepsy and Metabolic Disorders in Germany, Austria, and Switzerland

Objective: Ketogenic diet therapies (KDTs) such as classical ketogenic diet (kKD) and modified Atkins diet (MAD) have been used in the treatment of drug-resistant epilepsy, epilepsy syndromes, and are proven therapy for some rare metabolic disorders (glucose 1 transporter deficiency syndrome (GLUT1 DS) and pyridoxal dehydrogenase (PDH) deficiency. An early introduction of KET in specific syndromes has proven efficiency, especially with regard to the rate of seizure reduction and the influence on the psychomotor development.

Aims: Systematic retrospective data collection based on a questionnaire regarding the use of KDTs in 19 centers in Germany, Austria, and Switzerland (DACH).

Questions: In which diagnoses are KDTs used and how effective are KDTs? Does the form of the applied diet change in the course of the survey? In which forms of epilepsy and epilepsy syndromes are KDT particularly effective?

Methods: The patient data were collected by online survey from November 2012 to October 2015, so that the patients, in whom the KDT were initiated, were recorded retrospectively from the period between November 2011 and October 2014. The following data were determined: type of KDT used, diagnosis of patients, diagnosis of responders (seizure reduction > 50%), average number of anticonvulsants prior to initiation of KDT, and occurrence of adverse reactions.

Results: A total of 463 patients were started on one of the KDTs during the period, of which 56% were on kKD and 44% on MAD. The responder rate in case of the diagnosis of epilepsy/epilepsy syndromes was 46 to 48%. In particular, patients with the following diagnoses were good responder: myoclonoastatic epilepsy (MAE) (89% responder), Dravet’s syndrome (70% responder), and BNS epilepsy (67% responder). In patients with CSWS, 45% were considered responders. Patients with metabolic diseases (GLUT1 DS, PDH deficiency, and mitochondrial complex 1 deficiency) showed a significantly higher responder rates between 62 and 90%.

The mean number of anticonvulsant drugs before starting the KDT was 4.7 (range: 2–9). Most commonly reported adverse events were gastrointestinal symptoms, but patients did not prematurely discontinue KDT because of the side effects but because of noncompliance.

Conclusion: Although in this patient population a kKD have been primarily used, MAD is increasingly used in patients with epilepsy and epileptic syndromes. This form of KDT has shown to be similarly effective for seizure reduction in comparison to a kKD and due to its milder food restriction, MAD is more feasible, especially in older children and adolescents. In case of the diagnosis of a MAE, Dravet’s syndrome, BNS, and CSWS, the KET should be strongly considered and used early in the course of the disease because of their beneficial effect.