Background: To investigate the relationship with prognosis, various neurotological examinations evaluating all four nerves within the internal auditory canal were performed in patients with Bell's palsy. Methods: A total of 69 consecutive patients with Bell's palsy were included. They were treated uniformly with steroid and an antiviral agent and underwent neurotological examinations consisting of electronystagmography, pure-tone audiometry (PTA), electroneurography (ENoG), caloric test, rotatory chair test and cervical vestibular evoked myogenic potentials (cVEMP). According to the final recovery state, patients were divided into two groups: a complete recovery group and an incomplete recovery group. The incidence of abnormal findings in each test was compared between the two groups. Results: Fifty-six patients recovered completely and 13 patients recovered incompletely. No association was observed between the rate of ipsilesional PTA threshold and the rate of abnormal caloric test, function tests and recovery state. However, the initial state of facial palsy, ENoG and the rate of abnormal cVEMP were significantly correlated with the rate of recovery. Conclusion: The results indicate that Bell's palsy may be more comparable to mononeuritis multiplex and that cVEMP could be a useful tool for predicting the prognosis of Bell's palsy.
