The authors have no funding, financial relationships, or conflicts of interest to disclose.
Facial synkinesis after experimental compression of the facial nerve comparing intratemporal and extratemporal lesions†
Article first published online: 18 MAR 2010
Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 120, Issue 5, pages 1022–1027, May 2010
How to Cite
Yamada, H., Hato, N., Murakami, S., Honda, N., Wakisaka, H., Takahashi, H. and Gyo, K. (2010), Facial synkinesis after experimental compression of the facial nerve comparing intratemporal and extratemporal lesions. The Laryngoscope, 120: 1022–1027. doi: 10.1002/lary.20840
- Issue published online: 21 APR 2010
- Article first published online: 18 MAR 2010
- Manuscript Accepted: 2 DEC 2009
- Manuscript Received: 10 NOV 2009
- facial nerve;
- facial nucleus;
- fluorescent retrograde tracer;
- Level of Evidence: 2a.
The anatomical configuration of the facial nerve differs greatly between the intratemporal and extratemporal portions. The purpose of this study was to investigate the incidence of facial synkinesis and misdirection on clamping the facial nerve at the intratemporal or extratemporal portion of the facial nerve in guinea pigs.
In 16 guinea pigs, the facial nerve was clamped with microsurgical needle forceps at either the extratemporal (group A) or intratemporal (group B) segment. Facial nerve function was evaluated 1 week postoperatively using electroneurography (ENoG), and the incidence of facial synkinesis was evaluated 15 weeks postoperatively using an evoked blink reflex test. Fifteen weeks postoperatively, two retrograde fluorescent tracers (Dil [1-1′-dioctodecyl-3,3,3′,3′-tetramethyl-indocarbocyanine perchlorate] and True Blue) were injected into the facial muscles to observe reorganization of the facial nucleus.
No significant difference in the ENoG threshold was observed between groups A and B. In group A, none of the animals developed facial synkinesis and the somatotopic organization of the facial nucleus was not disturbed. In contrast, synkinesis occurred and the somatotopic organization was disturbed in group B.
A lack of funicular structure within the intratemporal facial nerve increases the possibility of misdirected regenerating axons and synkinesis. Laryngoscope, 2010