Electrical neurostimulation for chronic pain: on selective relay of sensory neural activities in myelinated nerve fibers

TL;DR

This study presents a simulation model to understand how electrical neurostimulation interacts with sensory neural activities in myelinated fibers, aiming to improve chronic pain treatment strategies.

Contribution

A simple simulation test bed for electrical neurostimulation of myelinated nerve fibers with sensory activity, addressing limitations of previous pain transmission models.

Findings

Interactions mainly due to action potential collisions and refractory periods.

Reliability of sensory activity decreases with higher stimulation frequencies.

Model provides insights into pain transmission modulation by neurostimulation.

Abstract

Chronic pain affects about 100 million adults in the US. Despite their great need, neuropharmacology and neurostimulation therapies for chronic pain have been associated with suboptimal efficacy and limited long-term success, as their mechanisms of action are unclear. Yet current computational models of pain transmission suffer from several limitations. In particular, dorsal column models do not include the fundamental underlying sensory activity traveling in these nerve fibers. We developed a (simple) simulation test bed of electrical neurostimulation of myelinated nerve fibers with underlying sensory activity. This paper reports our findings so far. Interactions between stimulation-evoked and underlying activities are mainly due to collisions of action potentials and losses of excitability due to the refractory period following an action potential. In addition, intuitively, the reliability of sensory activity decreases as the stimulation frequency increases. This first step opens the door to a better understanding of pain transmission and its modulation by neurostimulation therapies.