Literature reports in Japan dealing with the effects of medical treatments for sudden sensorineural deafness (SSD) published between 1989 and 2006 were reviewed. The review revealed that over the 18-year period, there have been no remarkable improvements in the results of medical treatments for SSD. The total number of patients included in the review was 9282. The reported results of medical treatments are as follows, cure 33.2%, remarkable recovery 25.9%, recovery 22.4%, and no change 18.5%. The relation between the number of patients examined in each of the reports and the obtained cure rates were also investigated. The differences in the obtained cure rates became larger as the total number of patients examined decreased. In the reports in which more than 200 patients were examined, the obtained cure rates were almost the same (around 30%). There were no differences in the medical treatments adopted among the papers. These findings suggest that the differences in the reported cure rates for SSD are not likely to be related to the medical treatments and are more likely to be due to sponteneous resolution. Before starting medical treatment for SSD, adequate information about SSD should be given to the patients; it should be emphasized that there are no clinical treatments yet that are adequately effective for SSD.
We report the change over the last 30 years of the age at which infants with hearing loss begin to wear hearing aids. The subjects were 393 infants fitted with hearing aids at the Ibaraki Medical Center. We divided the period between 1979 and 2008 into five six-year blocks (I: 1979-1984, II: 1985-1990, III: 1991-1996, IV: 1997-2002, V: 2003-2008), and investigated the distribution in the time-blocks of the age at which infants with hearing loss began to wear hearing aids. The results were stratified into two groups; infants with mild-moderate hearing loss (average hearing level<70dB) and infants with severe hearing loss group (average hearing level≥70dB). The following results were obtained. 1) Mild-to-moderate hearing loss group: During period I (1979-1984), the number of infants under 4 years of age wearing hearing aids was only 15%. Thereafter, the number of infants wearing hearing aids at a young age increased progressively, until the number of infants under 4 years of age and under 2 years of age wearing hearing aids increased to 87%, and 55% during period V (2003-2008). 2) Severe hearing loss group: There was little change in the age distribution from period I (1979-1984) to period IV (1997-2002). During period V (2003-2008), however , the number of infants under 1 year of age wearing hearing aids increased rapidly to 48%.
Auditory brain-stem response (ABR) and auditory steady-state response (ASSR) were examined in 60 of 450 infants in the neonatal intensive care unit (NICU) of our university hospital. The relationships between the results of evaluation of the ABR/ASSR and the risk factors for hearing loss (gestational age, birth weight, APGAR score, hyperbilirubinemia, severe respiratory disorder, chromosomal abnormalities, and cranial malformation) were evaluated. The thresholds of ASSR and wave V of ABR were well-correlated. Forty-two cases were diagnosed as having normal hearing in the first examination and 18 cases required a second examination. Finally, 11 (2.4% of infants in NICU) cases were diagnosed as showing hearing impairment, including four cases of otitis media with effusion, one case of unilateral hearing loss, and six cases of bilateral moderate to severe hearing loss. Five of the six infants with bilateral hearing loss had three or more risk factors. The second examination revealed that seven of the 18 cases had normal hearing level. Six of the seven cases underwent the first examination less than one month of the revised age. In conclusion, although the percentage of cases with hearing impairment among infants in the NICU is high, the first auditory examination should be performed at more than one month of the revised age.
We examined the relationship between the speech discrimination score and the percentage of correct answers to individual monosyllabic words in 144 ears. The subjects were classified into three groups by the speech discrimination score. The percentage of correct answers in each group were plotted as a function of that in the subject population overall, and these graphs were compared with one another. The Decrease in the percentage of correct answers were not observed equally for all the words, but for particular words for which the percentage of correct answers was low in the subject population overall. There are monosyllabic words for which the percentage of correct answers was high in the low speech discrimination score group. On the other hand, there were also monosyllabic words for which the percentage of correct answers was low in the high speech discrimination score group. The results of this study suggest that the relationship between the speech discrimination score and the percentage of correct answers should be taken into account while undertaking auditory training.
Auditory neuropathy, renamed by consensus at a recent international conference as auditory neuropathy spectrum disorder (ANSD), is a specific form of hearing loss defined by normal otoacoustic emissions, but severely abnormal or completely absent auditory brainstem responses. We investigated the distribution of auditory steady-state response (ASSR) thresholds in 9 infants and young children with ANSD. The large variability of ASSR thresholds indicated the heterogeneous nature of this disorder. Correlation values showed a significant positive relationship (p<0.05) between ASSR and conditioned orientation response audiometry (COR) thresholds at 500-4000Hz. To estimate the functional gains obtained from the use of hearing aids, we examined the dB difference between unaided and aided thresholds of ASSR and COR. The average functional gains estimated by the ASSR thresholds were up to 15 dB at 500-4000Hz, which were slightly lower than those estimated by the COR thresholds. ASSR testing is considered to be useful for hearing aid validation when behavioral test methods are inconclusive. ASSR may be useful for the estimation of residual auditory capacities and hearing aid benefits in infants and very young children with ANSD.