Case Report: Change in Electrocorticogram Detection of RNS with Initiation of Ketogenic Diet (P4.5-020)

Objective: We report a single case of NeuroPace RNS electrocorticogram (ECoG) detection changes observed in conjunction with initiation of the ketogenic diet. The electrographic signals detected by RNS declined gradually then leveled off once the patient reached ketosis. Background: The NeuroPace RNS is a closed-loop implanted neurostimulator, FDA approved for treatment of drug-resistant partial seizures. The neurostimulator utilizes detection algorithms defined as ictal activity by the clinician. Patients, as part of their treatment paradigm, may also employ the ketogenic diet to provide additional anti-convulsant effects. Design/Methods: During the initiation of the ketogenic diet, the detection algorithms remained unchanged. Utilizing the Patient Data Management System (PDMS), over the course of a week as the patient modified the diet towards ketosis, the number of detections and stored ECoGs was observed. Results: Review of stored ECoGs demonstrated a dramatic change in the electrographic signal. The number of detections gradually decreased as the patient reached ketosis and then leveled off while the patient remained in ketosis. Formal seizure calendars were not kept but by report, the diurnal seizures were eliminated and the patient reported fewer nocturnal seizures. Conclusions: The NeuroPace RNS demonstrated a significant reduction in event detections coincident with initiation of the ketogenic diet in a single case. This detection change may represent a significant improvement in seizure frequency or it may suggest a change in ECoG patterns with the initiation of ketosis. Such detection changes may require clinicians to re-evaluate detection settings as patients pursue dietary treatments. Alternatively, RNS detection may allow clinicians to monitor patients on the ketogenic diet using detections and stored ECoGs. Further analysis of patients on the ketogenic diet with the NeuroPace RNS is necessary. Disclosure: Dr. Greenwood has nothing to disclose. Dr. Nune has nothing to disclose. Dr. Lee has nothing to disclose. Dr. Liu has nothing to disclose. Dr. Heck has nothing to disclose.