Transcutaneous and Direct Electrical Stimulation of Mouse Sciatic Nerve Accelerates Functional Recovery After Nerve Transection and Immediate Repair.

Abstract

Electrical stimulation can accelerate peripheral nerve regeneration after injury and repair. Clinically, direct electrical stimulation (DES) may involve longer operating times, increasing risks of perioperative complications. Transcutaneous electrical stimulation (TCES) is a noninvasive alternative. In this study, we investigate how transcutaneous and DES compare for accelerating functional nerve recovery in a mouse sciatic nerve model. Twenty-eight mice were divided into sham (n = 4), axotomy (n = 8), DES (n = 8), and TCES (n = 8) groups. After sciatic nerve transection and repair, the proximal nerve was subjected to DES or TCES at 20 Hz for 1 hour. Sciatic functional index was measured before the injury, and at weeks 1, 2, 4, 6, 8, 10, and 12 by walking-track analysis. Electrophysiological measures were taken at week 12. Kinematic studies showed significant improvement from the 8th week to the 12th week for both electrical stimulation groups compared with the axotomy group (P < 0.05), with no difference between the electrical stimulation groups. At the 12th week, both DES and TCES groups had significantly faster average conduction velocity than the axotomy group. Functional recovery was significantly better from 8 weeks onward in mice receiving either DES or TCES stimulation when compared with axotomy and repair alone. Transcutaneous electrical stimulation is a minimally invasive alternative treatment for accelerating functional recovery after peripheral nerve injury.