Short-term electrical stimulation to promote nerve repair and functional recovery in a rat model

Purpose: To evaluate the effect of duration of electrical stimulation on peripheral nerve regeneration and functional recovery. Based on previous work, we hypothesized that applying 10 minutes of electrical stimulation to a 10-mm rat sciatic nerve defect would significantly improve nerve regeneration and functional recovery compared with the non-electrical stimulation group.

Methods: A silicone tube filled with a collagen gel was used to bridge a 10-mm nerve defect in rats, and either 10 minutes or 60 minutes of electrical stimulation was applied to the nerve during surgery. Controls consisted of a silicone tube with collagen gel and no electrical stimulation or an isograft. We analyzed recovery over a 12-week period, measuring sciatic functional index and extensor postural thrust scores and concluding with histological examination of the nerve.

Results: Functional assessment scores at week 12 increased 24% in the 10-minute group as compared to the no stimulation control group. Electrical stimulation of either 10 or 60 minutes improved the number of nerve fibers over no stimulation. Additionally, the electrical stimulation group's histomorphometric analysis was not different from the isograft group.

Conclusions: Several previous studies have demonstrated the effectiveness of 60-minute stimulations on peripheral nerve regeneration. This study demonstrated that an electrical stimulation of 10 minutes enhanced several functional and histomorphometric outcomes of nerve regeneration and was overall similar to a 60-minute stimulation over 12 weeks.

Clinical relevance: Decreasing the electrical stimulation time from 60 minutes to 10 minutes provided a potential clinically feasible and safe method to enhance nerve regeneration and functional recovery.