Antidromically evoked facial nerve response in guinea pigs - a long-term follow-up after nerve injury.
CONCLUSIONS
The present animal experiment supported that the antidromically evoked facial nerve response (AFNR) was useful for the early diagnosis of facial palsy and for assessing its recovery course.


OBJECTIVE
Chronological changes of AFNR latencies after nerve damage were investigated to examine whether or not AFNR latency was suitable as a parameter for the assessment of facial nerve function.


METHODS
AFNR were recorded in guinea pigs with and without the total or partial transection of the facial nerve. Chronological changes of AFNR after facial nerve transection were investigated.


RESULTS
48 h after the total transection, the responses almost completely disappeared, and reappeared after 3 weeks. The latencies of the recovered responses were prolonged then but shortened thereafter. Meanwhile, the partial transection did not result in a total loss of AFNR, but in a decrease of the amplitude and prolongation of the latency. One day after the partial transection, the latencies of the responses had already prolonged. From the 3rd to the 7th day, the latencies progressively prolonged, and then shortened by the 14th day.
Tashima
Kazuyuki
K
Department of Otolaryngology, Kochi Medical School, Nankoku, Kochi, Japan.
Takeda
Taizo
T
Nakatani
Hiroaki
H
Hamada
Masashi
M
Kakigi
Akinobu
A
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D005154:Facial Nerve / Q000503:physiopathology*; D005158:Facial Paralysis / Q000503:physiopathology*; D005500:Follow-Up Studies; D006168:Guinea Pigs; D009431:Neural Conduction / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D020196:Trauma, Nervous System / Q000503:physiopathology*