Timing of Applying Electrical Stimulation Is an Important Factor Deciding the Success Rate and Maturity of Regenerating Rat Sciatic Nerves

Abstract

Background. The timing of electrical stimulation (ES) after peripheral nerve transection may enhance axonal regeneration and functional recovery. Objective. The authors examined whether percutaneous ES at 1 mA and 2 Hz affects regeneration between the proximal and distal nerve stumps. Methods. Four groups of adult rats were subjected to sciatic nerve section followed by repair using silicone rubber conduits across a 10-mm gap. All groups received ES for 15 minutes every other day for 2 weeks. Stimulation was initiated on day 1 following the nerve repair for group A, day 8 for group B, and day 15 for group C. The control group D received no ES. Results. At 6 weeks after surgery in groups B and C, histological evaluations showed a significantly higher number of regenerated myelinated fibers in the sciatic nerve, and the electrophysiological results showed higher levels of reinnervation with relatively larger mean values of amplitudes, durations, and areas of compound muscle action potentials compared with A and D. Conclusion. A short delay in the onset of ES may improve the recovery of a severe peripheral nerve injury, which should be considered as a way of augmenting rehabilitative approaches.