Evaluation of functional recovery of recurrent laryngeal nerve using transoral laryngeal bipolar electromyography: a rat model.
OBJECTIVE
We developed a standardized method of minimally invasive transoral laryngeal (ToL) bipolar electromyography (EMG) for evaluation of recurrent laryngeal nerve (RLN) recovery after a controlled crush injury in a rat model.


METHODS
Ten 200- to 250-g Sprague-Dawley rats underwent a controlled crush injury to the left RLN performed with 60 seconds of use of a calibrated aneurysm clamp with a closing force of 0.61 N. Serial ToL bipolar EMG was performed on adductor muscles and the posterior criocoarytenoid muscle during spontaneous vocal fold motion under anesthesia. Each animal underwent ToL EMG immediately after surgery and 1, 3, and 6 weeks after surgery.


RESULTS
The EMG signals showed normal motor unit potentials and recruitment patterns 3 weeks after crush injury. Endoscopic evaluation of vocal fold mobility yielded consistently normal findings 6 weeks after crush injury.


CONCLUSIONS
We have developed a standardized method of crush injury to the rat RLN model and a minimally invasive transoral bipolar spontaneous EMG technique to serially evaluate and follow nerve injury and recovery in rats. This model is intended to simulate intraoperative RLN injury, to elucidate the electrophysiological events that occur during nerve recovery, and to form the basis for studying agents to enhance such recovery.
Tessema
Belachew
B
Department of Otolaryngology, New York Eye and Ear Infirmary, New York, NY 10003, USA.
Pitman
Michael J
MJ
Roark
Rick M
RM
Berzofsky
Craig
C
Sharma
Sansar
S
Schaefer
Steven D
SD
D000818:Animals; D004576:Electromyography / Q000379:methods; D007049:Iatrogenic Disease; D007431:Intraoperative Complications; D009055:Mouth; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D014826:Vocal Cord Paralysis / Q000209:etiology / Q000628:therapy*