Satoshi Iwasaki

Nationwide epidemiological survey of idiopathic sudden sensorineural hearing loss in Japan

Abstract Objectives: Using a large-scale nationwide survey database, we investigated the epidemiological characteristics for idiopathic SSNHL in Japan. Methods: The subjects for this analysis were patients registered in a Japanese multicentre database between April 2014 and March 2016. A total of 3419 idiopathic SSNHL patients were registered in the database, and the clinical characteristics of the idiopathic SSNHL patients were obtained. Several factors associated with the severity of hearing impairment and prognosis were then investigated. Statistical analysis was performed to clarify the factors associated with the severity of hearing impairment and prognosis. Results: There were significant correlations between the severity of hearing loss and diabetes mellitus, kidney disease, past history of brain infarction, heart disease, age (under 16 years/elderly), and symptoms of vertigo/dizziness. We also analyzed the prognostic factors for idiopathic SSNHL, and found that the severity of hearing loss (Grade 3 or 4), heart disease, aged 65 years or over, time from onset to treatment (over 7 days), and symptoms of vertigo/dizziness were all significantly related to poor prognosis. Conclusion: The present large-scale clinical survey revealed current epidemiological trends for idiopathic sudden sensorineural hearing loss (SSNHL) and various factors associated with the severity of hearing impairment and prognosis.

The effect of initial treatment on hearing prognosis in idiopathic sudden sensorineural hearing loss: a nationwide survey in Japan

Abstract Objective: To investigate the hearing prognosis of idiopathic sudden sensorineural hearing loss (SSNHL) treated with different initial therapies. Methods: Subjects consisted of patients diagnosed with idiopathic SSNHL within 7 days from onset and showing severe hearing loss (≥60u2009dB), who were registered in a Japanese multicenter database between April 2014 and March 2016. Subjects were divided into four groups according to initial therapy: (1) steroids, (2) steroidsu2009+u2009Prostaglandins (PGs), (3) intratympanic steroids (ITS), and (4) no steroids. Hearing outcomes were compared among the groups. Results: In total, 1305 patients were enrolled. The final hearing level and hearing gain of patients treated with steroidsu2009+u2009PGs were significantly higher than those of patients treated with steroids alone or no steroids. The ratio of good prognosis (complete recovery or marked improvement) in patients treated with steroidsu2009+u2009PGs was higher than that in patients treated with steroids alone or no steroids. There was no difference in the prognosis of patients treated with steroids alone or no steroids. Conclusion: A large number of patients with idiopathic SSNHL were registered in a multicenter database. PG use in combination with steroid administration was associated with a good hearing prognosis in patients with severe hearing loss.

POU4F3 mutation screening in Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis identified novel variants associated with autosomal dominant hearing loss

A variant in a transcription factor gene, POU4F3, is responsible for autosomal dominant nonsyndromic hereditary hearing loss, DFNA15. To date, 14 variants, including a whole deletion of POU4F3, have been reported to cause HL in various ethnic groups. In the present study, genetic screening for POU4F3 variants was carried out for a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA15 in the Japanese population. Massively parallel DNA sequencing of 68 target candidate genes was utilized in 2,549 unrelated Japanese HL patients (probands) to identify genomic variations responsible for HL. The detailed clinical features in patients with POU4F3 variants were collected from medical charts and analyzed. Novel 12 POU4F3 likely pathogenic variants (six missense variants, three frameshift variants, and three nonsense variants) were successfully identified in 15 probands (2.5%) among 602 families exhibiting autosomal dominant HL, whereas no variants were detected in the other 1,947 probands with autosomal recessive or inheritance pattern unknown HL. To obtain the audiovestibular configuration of the patients harboring POU4F3 variants, we collected audiograms and vestibular symptoms of the probands and their affected family members. Audiovestibular phenotypes in a total of 24 individuals from the 15 families possessing variants were characterized by progressive HL, with a large variation in the onset age and severity with or without vestibular symptoms observed. Pure-tone audiograms indicated the most prevalent configuration as mid-frequency HL type followed by high-frequency HL type, with asymmetry observed in approximately 20% of affected individuals. Analysis of the relationship between age and pure-tone average suggested that individuals with truncating variants showed earlier onset and slower progression of HL than did those with non-truncating variants. The present study showed that variants in POU4F3 were a common cause of autosomal dominant HL.

Idiopathic sudden sensorineural hearing loss and acute low-tone sensorineural hearing loss: a comparison of the results of a nationwide epidemiological survey in Japan

Abstract Objectives: The aim of this study was to investigate the differences between idiopathic sudden sensorineural hearing loss (SSNHL), and acute low-tone sensorineural hearing loss (ALHL) using the results of a nationwide survey database in Japan and to analyze the variables associated with their clinical features and the severity of hearing impairment, treatment, and prognosis. Methods: Participants were patients registered between April 2014 and March 2016 in a multicenter epidemiological survey database involving 30 university hospitals and medical centers across Japan. Statistical analysis was performed to clarify the factors associated with their clinical characteristics and the severity of hearing impairment, treatment, and prognosis. Results: Idiopathic SSNHL and ALHL differed significantly in terms of male-to-female ratio, age distribution, and time from onset to start of treatment. The treatment methods and hearing prognosis also differed markedly between the two diseases. A majority (92%) of idiopathic SSNHL patients were administered some type of corticosteroid, while half of the ALHL patients received corticosteroids and a diuretic agent. Conclusion: The results suggested that idiopathic SSNHL and ALHL belonged to different categories of inner ear disease.

Long-term results of hearing preservation cochlear implant surgery in patients with residual low frequency hearing

Abstract Conclusion: Differences were found between patients with stable hearing and those with progressive hearing loss in the lower frequencies with respect to the rate of progression in the contralateral ear. It is suggested that the electric acoustic stimulation (EAS) can provide improvement in hearing ability over the long-term if residual hearing might be lost to some extent. Objective: To evaluate the long-term threshold changes in the low frequency hearing of the implanted ear as compared with the non-implanted ear, and the hearing abilities with EAS along with the extent of residual hearing. Methods: Seventeen individuals were enrolled and received the EAS implant with a 24-mm FLEXeas electrode array. Hearing thresholds and speech perception were measured pre- and post-operatively for 1–5 years. Post-operative hearing preservation (HP) rates were calculated using the preservation numerical scale. Results: The average linear regression coefficient for the decline in hearing preservation score was −6.9 for the implanted ear and the patients were subsequently categorized into two groups: those with better than average, stable hearing; and those with worse than average, progressive hearing loss. EAS showed better results than electric stimulation alone, in spite of an absence of speech perception with acoustic stimulation.

Epidemiological survey of acute low-tone sensorineural hearing loss

Abstract Objectives: A nationwide epidemiological survey involving 23 hospitals in Japan was conducted and the predictive values of demographic data were examined statistically. Methods: A total of 642 patients from 23 hospitals, including 20 university hospitals, in Japan were enrolled in the study. Age ranged from 8 to 87 years, and all were diagnosed with acute low-tone sensorineural hearing loss (ALHL) between 1994 and 2016. Demographic data for the patients, such as symptoms, gender, mean age, and distribution of ALHL grading, were collected and analyzed in relation to prognosis using Student’s t-test, χ2 test and logistic regression. Results: Female gender (pu2009<u2009.013), younger age (pu2009<u2009.001), low-grade hearing loss (pu2009<u2009.001), and shorter interval between onset and initial visit (pu2009<u2009.004) were significantly predictive of a good prognosis. The prognosis for definite ALHL was significantly better than that for probable ALHL (pu2009<u2009.007). Conclusions: The severity of initial hearing loss, interval between onset and initial visit and age were important prognostic indicators for ALHL, while female gender was an important prognostic indicator peculiar to ALHL.

The effects of cochlear implantation in Japanese single-sided deafness patients: five case reports

Abstract Conclusion Cochlear implantation (CI) for Japanese single-sided deafness patients resulted in improved speech perception, increased sound localization accuracy, and reduced tinnitus handicap. Objectives This study reports results for five adult SSD cases with CI, focusing on the benefits they obtained in terms of speech recognition, sound localization, and tinnitus handicap. Methods Five Japanese patients meeting the eligibility criteria were included in this study. All patients were implanted with a fully inserted MED-EL Concerto FLEX28® implant (MED-EL, Innsbruck, Austria). Speech perception outcomes in noise, as well as sound localization and tinnitus disturbance, were assessed pre-surgically and at 1, 3, 6, and 12 months after CI activation. Results The Japanese monosyllable test score in noise improved gradually after implantation. In some cases, speech perception ability appeared unstable, particularly in the first 1–6 months after implantation. The sound localization ability showed marked improvement in all cases, with the disturbance to daily life caused by tinnitus also decreasing in all cases from the early post-operative period.

Differences between acoustic trauma and other types of acute noise-induced hearing loss in terms of treatment and hearing prognosis

Abstract Objectives: To evaluate the differences between acoustic trauma (AT) and other types of acute noise-induced hearing loss (ANIHL), we performed a literature search and case reviews. Methods: The literature search based on online databases was completed in September 2016. Articles on ANIHL and steroid treatment for human subjects were reviewed. The source sounds and treatment sequelae of our accumulated cases were also reviewed. Hearing loss caused by gun-shots and explosions was categorized into the AT group, while hearing loss caused by concerts and other noises was categorized into the ANIHL group. Results: Systemic steroid treatment did not appear to be effective, at least in the AT group, based on both the literature and our case reviews. However, effective recovery after treatment including steroids was observed in the ANIHL group. The difference in hearing recovery between the AT and ANIHL groups was statistically significant (pu2009=u2009.030), although differences in age, days from the onset to treatment and pretreatment hearing levels were not significant. Conclusions: Hearing recovery from AT is very poor, whereas, ANIHL is recoverable to some extent. Therefore, it is essential to differentiate between these two groups for accurate prediction of the hearing prognosis and evaluation of treatment effects.

Association between impaired IL-10 production following exposure to Staphylococcus aureus enterotoxin B and disease severity in eosinophilic chronic rhinosinusitis

BACKGROUNDnIL-10 is a major anti-inflammatory cytokine that prevents inflammation-mediated tissue damage. We characterized the production of IL-10 by sinonasal tissue cells following exposure to Staphylococcus aureus enterotoxin B (SEB), which elicits cellular responses and is associated with the pathogenesis of eosinophilic chronic rhinosinusitis (ECRS).nnnMETHODSnDispersed nasal polyp (NP) cells and uncinate tissue (UT) cells were prepared from patients with CRS with and without NP, respectively. Cells were incubated with SEB, and then the levels of IL-10 in the cell supernatants were determined. The effect of neutralizing IL-10 on SEB-induced IL-5, IL-13, IFN-γ, and IL-17A production was examined. Expression of IL-10 in NPs was also determined.nnnRESULTSnIL-10 was expressed in infiltrating inflammatory cells in NPs. NP cells, especially non-adherent NP cells, produced substantial amounts of IL-10 in response to SEB. Although baseline production of IL-10 was significantly higher in NP cells than UT cells, the degree of IL-10 response to SEB was not significantly different between the cell types. The degree of IL-10 production was negatively correlated with the degree of eosinophilia both in tissues and peripheral blood whereas positively correlated with the 1-s forced expiratory volume/forced vital capacity ratio. Patients with severe ECRS displayed a significant decrease in IL-10 production compared with those with non-ECRS. IL-10 neutralization significantly augmented SEB-induced IL-13 and IFN-γ production by NP cells.nnnCONCLUSIONSnImpaired IL-10 production in response to SEB in NP may exacerbate the pathophysiology of ECRS including eosinophilia and lower airway obstruction.

Language-specific strategy for programming hearing aids — A double-blind randomized controlled crossover study

OBJECTIVEnVoice-aligned compression (VAC) is a method used in Oticons hearing aids to provide more comfortable hearing without sacrificing speech discrimination. The complex, non-linear compression curve for the VAC strategy is designed based on the frequency profile of certain spoken Western languages. We hypothesized that hearing aids could be further customized for Japanese-speaking users by modifying the compression curve using the frequency profile of spoken Japanese.nnnMETHODSnA double-blind randomized controlled crossover study was performed to determine whether or not Oticons modified amplification strategy (VAC-J) provides subjectively preferable hearing aids for Japanese-speaking hearing aid users compared to the same companys original amplification strategy (VAC). The participants were randomized to two groups. The VAC-first group received a pair of hearing aids programmed using the VAC strategy and wore them for three weeks, and then received a pair of hearing aids programmed using VAC-J strategy and wore them for three weeks. The VAC-J-first group underwent the same study, but they received hearing aids in the reverse sequence. A Speech, Spatial and Qualities (SSQ) questionnaire was administered before beginning to use the hearing aids, at the end of using the first pair of hearing aids, and at the end of using the second pair of hearing aids.nnnRESULTSnTwenty-five participants that met the inclusion/exclusion criteria from January 1 to October 31, 2016, were randomized to two groups. Twenty-two participants completed the study. There were no statistically significant differences in the increment of SSQ scores between the participants when using the VAC- or the VAC-J-programmed hearing aids. However, participants preferred the VAC-J strategy to the VAC strategy at the end of the study, and this difference was statistically significant.nnnCONCLUSIONnJapanese-speaking hearing aid users preferred using hearing aids that were fitted with the VAC-J strategy. Our results show that the VAC strategy can be adjusted to the frequency profile of different languages and that participants expressed their subjective preference more clearly than was reflected in the SSQ scores. A similar language-specific strategy may improve users satisfaction while using hearing devices, and this concept may be extended to implantable hearing devices.nnnCLINICAL RESEARCH REGISTRATION NUMBERnR000023191.