[Research of relationship between endoneurial fluid pressure and electroneurography of the facial nerve].
OBJECTIVE
The relationship between endoneurial fluid pressure (EFP) and electroneurography (ENoG) of the facial nerve was studied in order to evaluate the ENoG as the basis of pathophysiology of the decompression of the facial nerve.


METHODS
The values of ENoG were recorded by an instrument of physiology on the normal and crushed facial nerves of guinea pigs. Endoneurial fluid pressures were measured by a servo-nulling micropipette system at the same time. After the EFP were measured, the facial nerves were removed and fixed properly for examination under the light and electron microscope in order to determine the differences from various periods after injury.


RESULTS
EFP in the facial nerve was changed significantly during the period of three days to three weeks later after crushed injury, and the percentage of degenerated facial nerve fibre was the same. There was positive correlation between ENoG and EFP. After crushed injury 2 and 3 weeks, the coefficient was 0.88 and 0.51, respectively. It could be found that extensive edema in endoneurial and perivascular spaces of the facial nerve occurred in early stage of injury, but numerous Schwann cells proliferation appeared in the later period.


CONCLUSIONS
The change of ENoG could reflect the value of EFP relatively within three weeks after crushed injury. It was suggested that ENoG could be useful in evaluating the pathogenesis underlying facial palsy. And it could be provided a basis indication for decompression of the facial nerve.
Chen
Bing
B
Department of Otorhinolaryngology, Eye Ear Nose & Throat Hospital of Fudan University, Shanghai 200031, China. bchen@citiz.net
Wang
De-hui
DH
Wang
Zheng-min
ZM
D000818:Animals; D004594:Electrophysiology; D005154:Facial Nerve / Q000503:physiopathology*; D020220:Facial Nerve Injuries / Q000473:pathology / Q000503:physiopathology*; D005158:Facial Paralysis / Q000503:physiopathology; D005260:Female; D006168:Guinea Pigs; D008297:Male; D008365:Manometry; D009462:Neurology / Q000379:methods; D011312:Pressure; D011897:Random Allocation