Abstract
In the very acute phase of Bell's palsy and Ramsay Hunt syndrome, the increased amplitudes of electroneuronography (ENoG) on the affected side are rarely observed on the intact side. The normal range of amplitude ratios in ENoG was obtained by testing 10 healthy volunteers and the results showed that the upper limit of the normal range was 129%. For the present study, ENoG was conducted on 42 patients with facial palsy who sought medical attention within 4 days of developing symptoms. In ten (24%) of these patients, the amplitude of ENoG exceeded 129% on the affected side (an abnormally large amplitude) within 4 days of developing symptoms. There was no VII nerve denervation in any patients with abnormally large amplitudes on ENoG, and their prognosis was found to be good. Thus, abnormally large amplitudes on ENoG indicated a favorable prognosis for facial palsy. The results suggest that abnormally large amplitudes on ENoG may predict the prognosis of facial palsy in the early stage of the disease.
