Background: Electrical stimulation of damaged peripheral nerve may aid regeneration.
Methods: A 10-mm gap was made in rat sciatic nerve by suturing the stumps into silicone rubber tubes. A control group received no stimulation. To determine whether 2 Hz of percutaneous electrical stimulation at 1 mA, 2 mA, or 4 mA augments regeneration between the proximal and distal nerve stumps.
Results: The groups receiving electrical treatment had larger mean values of axon number, endoneurial area, total nerve area, blood vessel number, and blood vessel area compared with the controls. In addition, the group receiving electrical stimulation, especially at 1 mA had significantly shorter latency, larger amplitude, larger area of the evoked muscle action potentials and faster conduction velocity compared with the controls. However, electrical stimulation at 4 mA provoked adverse responses to the function recovery of regenerated nerves in the kinematic gait analysis.
Conclusion: Indeed, the electrical stimulation appears to have a detrimental effect on the regeneration process. It could promote the growth of regenerating nerves; however, excessive direct current could be repulsive to regrowing fibers. This reveals the importance for physical therapists using safe stimulus protocols for rehabilitation purposes.