Robot-assisted responsive neurostimulator system placement in medically intractable epilepsy: Instrumentation and technique

BACKGROUND: The management of medically refractory epilepsy patients who are not surgical candidates has remained challenging. Closed loop—or responsive—neurostimulation (RNS) is now an established therapy for the treatment of epilepsy with specific indications. The RNS^R system (NeuroPace Inc, Mountainview, California) has recently been shown to be effective in reducing the seizure frequency of partial onset seizures. The electrode design consists of either intracerebral depth electrodes or subdural strip electrodes, and stereotaxis is typically used to guide placement into the EZ. Details on the operative techniques used to place these electrodes have been lacking. OBJECTIVE: To address the advantage of using a robotic-assisted technique to place depth electrodes for RNS^R system placement compared to the typical frame-based or frameless stereotactic systems. METHODS: We retrospectively reviewed our single center, technical operative experience with RNS^R system placement using robotic assistance from 2014 to 2016 via chart review. RESULTS: Twelve patients underwent RNS^R system placement using robotic assistance. Mean operative time was 121 min for a median of 2 depth electrodes with mean deviation from intended target of ∼3 mm in x, y, and z planes. Two patients developed wound infections, 1 of whom was reimplanted. Seizures were reduced by ∼40% at 2 yr, similar to the results seen in the open label portion of the pivotal RNS trial. CONCLUSION: Robotic-assisted stereotaxis can be used to provide a stable and accurate stereotactic platform for insertion of intracerebral RNS electrodes, representing a safe, efficient and accurate procedure.