1. Evaluate the indications and patient selection criteria for Neuropace  Responsive NeuroStimulator (RNS)

 2. Describe patient outcomes with RNS

We retrospectively reviewed all patients implanted with the RNS device for intractable epilepsy between 4/07 and 9/18. We collected lead placement data, response in seizure reduction to stimulation and adverse events related to the stimulator.

40 patients were implanted between 4/07 and 9/18 (31 post approval); 39 are being currently followed. Mesial temporal placement was most common (n=22, 3 unilateral), followed by neocortical (14) and mesial temporal plus other areas (3). Median follow-up has been 26.9 months (range: 0-124 months). 25 (64%) have had stimulation enabled for >6 months. Three (12%) reported seizure freedom, 68% had 50% seizure reduction and 40% had >90% reduction.  Median seizure reduction was 60% for mesial temporal placement (n=15), 94% for neocortical (n=5), and 92% for mesial temporal plus other locations (n=3). Ten had RNS and concurrent cortical resection; Of 3 patients with cortical resection and RNS placement, seizure reduction was 87-100%. Adverse events: lead fracture (1) post-operative complication (1) SUDEP (1) and psychological event (1).

RNS placement was safe and effective with only 7% developing adverse events. Two-thirds of patients responded with at least a fifty percent reduction in seizures and mesial temporal lobes were the most common region for placement of electrodes.