Morphometric Assessment of the Effectiveness of Post-Traumatic Regeneration of Peripheral Nerves Using Single and Repeated Courses of Electrostimulation

Abstract

The effects of electrostimulation (ES) on peripheral nerve regeneration were studied in 41 dogs by transection and microsuturing of the sciatic nerve (SN). The control group consisted of 23 animals, while 18 underwent ES of the spinal cord and SN using a 50-Hz alternating current; 13 animals received one course of 18 sessions 1–2.5 months after surgery (subgroup ES1) and five animals received a first courses at the same times and a second at 6–7.5 months after surgery (subgroup ES2). The mean diameter of myelinated fibers (MF) in subgroup ES1 was significantly greater than in controls at 2.5, 4, 6, and 12 months after surgery, mainly because of increases in axon diameter. At 12 months, subgroup ES2 and to a lesser extent subgroup ES1 showed a marked tendency to recovery of the bimodal distribution of MF diameter. Thus, ES was found to produce effective increases in MF regeneration and differentiation, though it led to relative hypomyelinization of MF.