[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.

CONCLUSION

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.