Facial Nerve Decompression in the Treatment of Peripheral Facial Nerve Palsy

Abstract

The prognosis of the peripheral facial nerve palsy is good on the whole. However, the prognosis is not favorable when nerve degeneration is severe in the early stage and when steroid therapy is delayed. The facial nerve decompression surgery could be applied to those patients with poor prognosis. The authors performed this study to analyze the results of the facial nerve decompression surgery using middle fossa approach and/or combined with transmastoid approach, and to evaluate its usefulness. This retrospective study was undertaken in 9 patients with peripheral facial nerve palsy who received facial nerve decompression surgery between Jan. 2003 and Dec. 2012. The number of patient with Bell's palsy and Herpes zoster oticus was 5 and 4, respectively. The patients comprise 3 men and 6 women, aged between 41 and 65 years (average age: 55.4 years). All patients had HB grade V of facial nerve palsy before surgery, and neural degeneration between 92 and 100% (average: 96.6%) in electroneurography (ENoG). The average time took until operation was 24.8 days (18–33). 7 out of 9 patients improved facial palsy to some extent within 1 week after operation. It took average of 7.3 weeks (1–15) to reach to HB grade III. It took average of 21.3 weeks (10–26) to reach the final degree of facial palsy which is HB grade I in 4 patients, and HB grade II in 5 patients on 1 year of follow-up. There was no relationship in causes of palsy or time to operation from onset of palsy with respect to the final degree of the palsy. 9 patients who have facial nerve palsy but not done surgical decompression are served as negative control. All of them showed facial palsy of H-B grade V. 6 of 9 patients were recovered to HB grade I or II. However, remaining 3 patients showed poor prognosis of facial palsy less than HB grade IV. Average 5 months (3–7 months) are required that improved to H-B grade III. The time taken to reach the final facial palsy status is average 9.12 months (3–24 months)