Electrical stimulation facilitates rat facial nerve recovery from a crush injury

Abstract

Objective: To study the effect of electrical stimulation on accelerating facial nerve functional recovery from a crush injury in the rat model.

Study design: Experimental.

Method: The main trunk of the right facial nerve was crushed just distal to the stylomastoid foramen, causing right-sided facial paralysis in 17 Sprague-Dawley rats. An electrode apparatus was implanted in all rats. Nine rats underwent electrical stimulation and eight were sham stimulated until complete facial nerve recovery. Facial nerve function was assessed daily by grading eyeblink reflex, vibrissae orientation, and vibrissae movement.

Results: An electrical stimulation model of the rat facial nerve following axotomy was established. The semi-eyeblink returned significantly earlier (3.71 + 0.97 vs 9.57 + 1.86 days post axotomy) in stimulated rats (P = 0.008). Stimulated rats also recovered all functions earlier, and showed less variability in recovery time.

Conclusion: Electrical stimulation initiates and accelerates facial nerve recovery in the rat model as it significantly reduces recovery time for the semi-eyeblink reflex, a marker of early recovery. It also hastens recovery of other functions.