Abstract
Objectives: Though prognostic assessments of facial palsy are generally performed using either electroneuronography (ENoG) or nerve excitability test (NET), an accurate prognosis is difficult to obtain within the first 7 days after disease onset. In this report, very early prognostic assessment was attempted using the antidromic facial nerve response (AFNR).
Methods: The subjects consisted of patients with facial paralysis (Bell's palsy, 40; Hunt syndrome, 14). The AFNR was examined chronologically during the first 7 days after disease onset. All of the patients received an intravenous infusion of hydrocortisone, and the Hunt syndrome patients also received aciclovir. Total amplitude of the biphasic AFNR wave (T-amp), the amplitude of the positive wave (P-amp), the amplitude of the negative wave (N-amp), and the ratio of the amplitude of the negative wave to the total amplitude (N/T ratio) were compared statistically using a t test between complete recovery group (House-Brackmann grade I or II) and incomplete recovery group (House-Brackmann grade III or IV).
Results: The T-amp, P-amp, and N-amp were not statistically different between the two groups, although the average values of each parameter were lower in the incomplete recovery group than in the complete recovery group. However, the N/T ratios appeared statistically different between the two groups and this ratio for the complete recovery group was maintained over 0.4 during the first 6 days after disease onset.
Conclusion: The AFNR may be useful for obtaining a prognosis of facial palsy during the initial stage. Further treatment may be necessary when the N/T ratio is less than 0.4.