Objective
To establish whether daily mechanical stimulation improves functional recovery of whisking after facial nerve transection injury/ repair in the rodent.
Methods
Forty rats underwent facial nerve transection injury/ repair, and subsequent quantitative facial movement testing. Animals were randomized into two experimental groups (n=20 each). Both groups received daily 5-minute manual stimulation of their whiskers, with one group undergoing whisker protraction and the other whisker retraction. Rats were tested on postoperative weeks 1, 4-8, and 15 using a validated, quantitative whisking kinematics apparatus. Whisks were counted and analyzed for whisking amplitude, velocity and acceleration.
Results
Animals receiving manual stimulation by passive protraction of their whiskers demonstrated significantly improved functional recovery at multiple time points during the 15 weeks compared with historical controls (p<.05, one-tailed t-test). Recovery was similar in the protraction and retraction groups, trending towards better whisking recovery in the protraction group.
Conclusions
The present report demonstrates that daily mechanical whisker stimulation significantly improves recovery of whisking after facial nerve transection/ repair in animals undergoing either protraction or retraction. This finding supports the role of early soft tissue manipulation after facial nerve repair, and may have clinical implications for the postoperative management of patients following facial nerve manipulations.