Daily facial stimulation to improve recovery after facial nerve repair in rats.
OBJECTIVE
To establish whether daily mechanical stimulation improves functional recovery of whisking after facial nerve transection injury and repair in rats.


METHODS
Forty rats underwent facial nerve transection injury and repair and subsequent quantitative facial movement testing. Animals were randomized into 2 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 through 8, and 15 via 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 < .005; 1-tailed t test). Recovery was similar in the protraction and retraction groups, trending toward better whisking recovery in the protraction group.


CONCLUSIONS
Daily mechanical whisker stimulation via either protraction or retraction significantly improves recovery of whisking after facial nerve transection and repair. 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 after facial nerve manipulations.
Lindsay
Robin W
RW
Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02114, USA. robin_lindsay@meei.harvard.edu
Heaton
James T
JT
Edwards
Colin
C
Smitson
Christopher
C
Vakharia
Kalpesh
K
Hadlock
Tessa A
TA
D000818:Animals; D020220:Facial Nerve Injuries / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D006234:Handling, Psychological; D009416:Nerve Regeneration / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D014738:Vibrissae / Q000502:physiology*