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Published on: February 23, 2015
Early assessment of nerve degeneration using the antidromic facial nerve response
Hiroaki Nakatani1, Mitsuru Iwai, Masashi Hamada
1Department of Otolaryngology, Kochi Medical School, Nankoku, Kochi, Japan. hnakatan@tcc.pref.tochigi.lg.jp
Conclusion:
The antidromic facial nerve response (AFNR) is recommended as a monitoring method to detect cases resulting in facial nerve degeneration within 1 week after onset in patients with Bell's palsy and Hunt syndrome.
Objectives:
The purpose of this study was to establish criteria for the AFNR to predict the prognosis of Bell's palsy and Hunt syndrome in the early stages, not exceeding 1 week after onset.
Materials And Methods:
54 patients, including 40 with Bell's palsy and 14 with Hunt syndrome, were examined in this study. All patients were tested for the AFNR within 1 week after onset of paralysis and AFNR waveforms were analyzed. Four AFNR parameters, the total (peak-to-peak) amplitude (T-amp), the amplitudes of the positive wave (P-amp) and the negative wave (N-amp), and the N-amp/T-amp (N/T) ratio, were compared with the outcomes of facial paralysis.
Results:
In most patients with poor outcomes, T-amp was <4 microV and N-amp was <2 microV. The mean value of the N/T ratio in patients with a poor outcome fell to <0.4 after the 3rd day from onset, while that in patients with a good outcome was stable between 0.4 and 0.6 during the first week.
