An experimental model of peripheral nerve electrical injury in rats.

INTRODUCTION: Although several studies have investigated models of nerve electrical injury, only a few have focused on electrical injury to peripheral nerves, which is a common and intractable problem in clinical practice. Here, we describe an experimental rat model of peripheral nerve electrical injury and its assessment.

METHODS: A total of 120 animals were subjected to short-term corrective electrostimulation (50 Hz, 1-s duration) applied at varying voltages (control, 65, 75, 100, 125, and 150 V) to the exposed left sciatic nerve. Behavioural testing, electrophysiological measurements, and histopathological observation of the sciatic nerve were conducted at 1-, 2-, 4-, and 8-w follow-ups.

RESULTS: No functional defects were noted in the groups that received 65-V stimulation at any time point. Sciatic nerve functional defects were found after 2 w in animals that received 75-V stimulation, but function returned to normal after 4 w. In animals that received 100-V and 125-V stimulation, functional defects were observed at 4 w, but had partially recovered by 8 w. Conversely, animals that received 150-V stimulation did not show recovery after 8 w.

CONCLUSION: We presented a model of peripheral nerve electrical injury that avoided the interference of various external factors, such as current instability, compression of the surrounding tissues, and altered blood supply. The model allowed quantitation and ranking of the nerve injury into four degrees. It facilitated effective evaluation of nerve function impairment and repair after injury. It can be used post-surgically to evaluate peripheral nerve impairment and reconstruction and enables translational interpretation of results, which may improve understanding of the mechanisms underlying the progression of peripheral nerve electrical injury.