Abstract
It is difficult to predict the prognosis of sudden hearing loss (SHL). Initial hearing level is commonly considered as a factor affecting the hearing outcome of SHL. The purpose of this study is to investigate the relationship between the initial residual hearing and the hearing outcome in profound SHL patients.
We compared the hearing outcome in 20 patients of total deafness and that in 47 patients of nearly-total deafness (profound SHL without residual hearing at more than three frequencies). In nearly-total deafness patients, we compared the hearing outcome at each of 7 frequencies (125-8kHz) with and without initial residual hearing. We also compared the final hearing level (PTA: pure-tone average) of patients with and without initial residual hearing at each frequency. The outcome in the total deafness patients was poor and the average of mean final PTA was 78dB, although that of nearly-total deafness was varied and the average was 52dB. In 7 frequencies of nearly-total deafness patients, the difference in hearing outcome at the frequency with and without initial residual hearing was largest at 2kHz and smallest at 500Hz.
The mean final PTA with initial residual hearing at 2kHz was 42dB, which was significantly smaller than 63dB, that without initial residual hearing. From these results, we concluded that the initial residual hearing at 2kHz might be a most important indicator predicting the prognosis of profound SHL.
