In-Human Demonstration of High-Frequency Reversible Electrical Motor Nerve Block Compared to Selective Neurectomy-A Proof-of-Concept Study.

Abstract

This is an in-human proof-of-concept series of cases that tested the possibility of replicating the effect of selective neurectomy with a high-frequency stimulation-generated nerve conduction block. During the selective tibial neurectomy surgery for spasticity in four participants, the exposed nerve was stimulated at 10 kHz with a commercially available linear 8-contact electrode passed adjacent to the nerve under direct vision. Proximal stimulation was performed using a bipolar probe 1 cm proximal to the blocking electrode. The effect of block and proximal stimulation was recorded using the continuous electromyography (EMG). High-frequency stimulation was stopped to assess reversibility. Subsequently, a neurectomy was performed, and direct stimulation testing was done proximal and distal to the neurectomy site. The effects of neurectomy on EMG were compared to those obtained with a high-frequency stimulation-generated nerve conduction block. In all patients, an onset response was seen, after which a graded partial to complete block was obtained. High-frequency stimulation-generated nerve conduction block was fully reversed shortly after stopping the stimulation. The EMG for proximal stimulation postneurectomy was comparable to that with HF-stimulated block. This demonstration of reversible electrical nerve block is a milestone toward the clinical implementation of high-frequency stimulation-mediated motor block for spasticity.