The Effect of Electrical Stimulation on Median Nerve Recovery After Repair in Rats.

Purpose: Studies have shown that electrical stimulation (ES) accelerates peripheral nerve recovery after repair. Electrical stimulation of 10 minutes or less improved functional and histological recovery in a murine model of sciatic nerve transection and repair. The primary purpose of our study was to determine if less than 10 minutes of ES can accelerate recovery in rats after median nerve transection and repair. Methods: Twenty-eight male Sprague Dawley rats underwent transection and primary repair of the median nerve proximal to the elbow. Rats were randomized into four groups: three groups received ES of 1, 5, or 10 minutes after nerve repair and one group received no ES. Grip strength was tested for 8 weeks, using previously described methods. These data were compared to a control group of rats with intact median nerves and no ES from our pilot study. After 8 weeks, rats were killed, and the bilateral flexor digitorum superficialis muscles and median nerves were harvested. The axon area proximal and distal to the nerve repair was measured histologically. Results: There was no significant difference in grip strength between the groups that received no ES versus ES of any duration. Axon area was lower distal to the repair site in the control rats without ES. We did not observe a difference in axon area distal to the nerve repair in the treatment groups. Conclusions: ES did not accelerate functional or histological healing of the median nerve after primary repair in rats. Level of evidence: 2B.