Evaluation of the ear ossicles with photon-counting detector CT.

Recently, computed tomography with photon-counting detector (PCD-CT) has been developed to enable high-resolution imaging at a lower radiation dose. PCD-CT employs a photon-counting detector that can measure the number of incident X-ray photons and their energy. The newly released PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Forchheim, Germany) has been in clinical use at our institution since December 2022. The PCD-CT offers several advantages over current state-of-the-art energy-integrating detector CT (EID-CT). The PCD-CT does not require septa to create a detector channel, while EID-CT does. Therefore, downsizing the anode to achieve higher resolution does not affect the dose efficiency of the PCD-CT. CT is an indispensable modality for evaluating ear ossicles. The ear ossicles and joints are clearly depicted by PCD-CT. In particular, the anterior and posterior legs of the stapes, which are sometimes unclear on conventional CT scans, can be clearly visualized. We present cases of congenital anomalies of the ossicular chain, ossicular chain dislocation, tympanosclerosis, and cholesteatoma in which PCD-CT was useful. This short article reports the usefulness of PCD-CT in the 3D visualization of the ear ossicles.

Cochlear Implantation in the Poorer-Hearing Ear Is a Reasonable Choice.

Choosing the optimal side for cochlear implantation (CI) remains a major challenge because of the lack of evidence. We investigated the choice of the surgery side for CI (i.e., the better- or poorer-hearing ear) in patients with asymmetric hearing. Audiological records of 74 adults with a unilateral hearing aid who had undergone surgery at Okayama University Hospital were reviewed. The definition of 'better-hearing ear' was the aided ear, and the unaided ear was considered the poorer-hearing ear. We performed a multiple regression analysis to identify potential predictors of speech recognition performance after unilateral CI in the patients. Fifty-two patients underwent CI in the poorer-hearing ear. The post-Ci bimodal hearing rate was far higher in the poorer-ear group (77.8% vs. 22.2%). A multivariate analysis revealed that prelingual hearing loss and the patient's age at CI significantly affected the speech recognition outcome (beta coefficients: 24.6 and -0.33, 95% confidence intervals [11.75-37.45] and [-0.58 to -0.09], respectively), but the CI surgery side did not (-6.76, [-14.92-1.39]). Unilateral CI in the poorer-hearing ear may therefore be a reasonable choice for adult patients with postlingual severe hearing loss, providing a greater opportunity for postoperative bimodal hearing.

Revision cochlear implant surgery in adults and children is a safe and effective technique: a retrospective single faculty study in Okayama University Hospital, Japan.

BACKGROUND: Cochlear implant (CI) surgery is a safe surgical technique, although some patients require revision CI surgery. AIMS/OBJECTIVES: This study investigated the cause and underlying reason of revision CI surgery as well as hearing outcomes in a single institution. PATIENTS AND METHODS: This retrospective study evaluated patients who underwent CI surgery between April 2006 to March 2022 (n = 351). Sex, aetiology of hearing loss (HL), age and period from initial CI surgery to reimplantation, cause of revision, and related factors were examined. RESULTS: Twelve patients (8 males, 4 females) received CI reimplantation. The revision surgery rate was 2.59% (3.15% children, 1.69% adults); the period from initial surgery to reoperation was 8.60 ± 6.56 years for 9 children with congenital HL and 15.27 ± 5.72 years for 3 adults with progressive HL. Device failure was the most common cause (n = 8), followed by infections (n = 2), advanced facial irritation symptoms (n = 1), and electrode slip-out (n = 1). Mean preoperative and postoperative CI thresholds were 44.0 ± 9.46 dBnHL and 39.19 ± 8.89 dBnHL (p < .068), respectively. CONCLUSION AND SIGNIFICANCE: Caregiver education, surgical technique advances, flap design, and extensive antibiotic use may decrease the revision surgery rate. The lack of post-revision deterioration of the hearing threshold contributed to well-being in patients with CI.

Etiology of hearing loss affects auditory skill development and vocabulary development in pediatric cochlear implantation cases.

BACKGROUND: Cochlear implantation (CI) is an effective treatment for severe-to-profound hearing loss patients and is currently used as the standard therapeutic option worldwide. However, the outcomes of CI vary among patients. AIMS/OBJECTIVES: This study aimed to clarify the clinical features for each etiological group as well as the effects of etiology on CI outcomes. MATERIALS AND METHODS: We collected clinical information for 308 pediatric cochlear implant cases, including the etiology, hearing thresholds, age at CI, early auditory skill development, total development, monosyllable perception, speech intelligibility and vocabulary development in school age, and compared them for each etiology group. RESULTS: Among the 308 CI children registered for this survey, the most common etiology of hearing loss was genetic causes. The genetic etiology group showed the most favorable development after CI followed by the unknown etiology group, syndromic hearing loss group, congenital CMV infection group, inner ear malformation group, and cochlear nerve deficiency group. CONCLUSIONS AND SIGNIFICANCE: Our results clearly indicated that the etiology of HL affects not only early auditory skill development, but also vocabulary development in school age. The results of the present study will aid in more appropriate CI outcome assessment and in more appropriate intervention or habilitation programs.

Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan.

Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a "typical" phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85-90% of the patients showed a hearing level of 20-39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed "true" auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype-phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype-phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.

Effects of Protective Measures against COVID-19 on Auditory Communication for People with Hearing Loss.

WHO has recommended various measures to combat the COVID-19 pandemic, including mask-wearing and physical distancing. However, these changes impair communication for individuals with hearing loss. We investigated the changes in auditory communication associated with COVID-19 measures in 269 patients (male: 45.7%, female: 54.3%, median age: 54 y.o.). Most patients with hearing loss had difficulty engaging in auditory communication with people wearing masks, especially in noisy surroundings or with physical distanc-ing. These difficulties were noticeable in patients with severe hearing loss. Developing communication support strategies for people with hearing loss is an urgent need while COVID-19 measures are in place.

Immediate changes in transcription factors and synaptic transmission in the cochlea following acoustic trauma: A gene transcriptome study.

Pathologic mechanisms in cochleae immediately following the onset of noise-induced hearing loss (NIHL) remain unclear. In this study, mice were exposed to 120 dB of octave band noise for 2 h to induce NIHL. Three hours after noise exposure, expression levels of the whole mouse genome in cochleae were analyzed by RNA-seq and DNA microarray. Differentially expressed genes (DEGs) exhibiting >2-fold upregulation or downregulation in noise-exposed cochleae compared to controls without noise exposure were identified. RNA-seq and microarray analyses identified 273 DEGs regulated at 3 h post-noise (51 upregulated and 222 downregulated). Bioinformatic analysis revealed that these DEGs were associated with the functional gene pathway "neuroactive ligand-receptor interaction" and included 28 genes encoding receptors for neurotransmitters such as gamma-aminobutyric acid and glutamate. Other DEGs included 25 genes encoding transcription factors. Downregulation of 4 neurotransmitter receptors (Gabra3, Gabra5, Gabrb1, Grm1) and upregulations of 5 transcription factors (Atf3, Dbp, Helt, Maff, Nr1d1) were validated by RT-PCR. The differentially regulated transcription factor Atf3 immunolocalized to supporting cells and hair cells in the organ of Corti at 12-h post-noise. The present data serve as a basis for further studies aimed at developing medical treatments for acute sensorineural hearing loss.

Prevalence and risk factors for delayed-onset hearing loss in early childhood: A population-based observational study in Okayama Prefecture, Japan.

OBJECTIVES: The aim of this study was to retrospectively document prevalence rates of delayed-onset hearing loss (DOHL) under 7 years old after passing the newborn hearing screening (NHS) program using its database in Okayama Prefecture, as well as records from Okayama Kanariya Gakuen (OKG, Auditory Center for Hearing Impaired Children, Okayama Prefecture, Japan). We explored the percentage of children with DOHL among all children who underwent the NHS and surveyed risk factors abstracted from their clinical records. METHODS: We collected data of 1171 children, who first visited OKG from April 2006 to March 2018. DOHL children were defined as bilaterally hearing-impaired children who were diagnosed under 7 years old after passing the NHS at birth. Based on the medical records, we investigated age at diagnosis, hearing levels, and risk factors. As population-based data of 168,104 children, the percentage of DOHL subjects was retrospectively calculated among the total number of children who underwent the NHS in Okayama Prefecture from April 2005 to March 2017. RESULTS: During the period, we identified 96 children with bilateral DOHL, of which 34 children had failed the NHS unilaterally and 62 had passed the NHS bilaterally. Among all children who underwent the NHS in Okayama Prefecture, the prevalence rate of DOHL in unilaterally referred infants was 5.2%, and 0.037% in bilaterally passed children. The prevalence of bilateral DOHL was 0.057% overall. Unilaterally referred children with DOHL were diagnosed at an average of 13.9 months, while bilaterally passed children with DOHL were diagnosed at an average of 42.3 months. Approximately 59.4% of children with DOHL had risk factors, among which family history of hearing loss was the most frequent. CONCLUSION: We propose the first English report of DOHL prevalence in the prefecture population in Japann, which is among the largest community-based population ever reported. The NHS is not a perfect strategy to detect all early-childhood hearing loss; therefore, careful assessment of hearing throughout childhood is recommended, especially in children with risk factors of hearing loss. Further interventional strategies must be established, such as regular hearing screening in high-risk children and assessments of hearing and speech/language development in public communities and nursery schools.

Progression of hearing loss and choice of hearing aids by patients in their 60s, 70s, and 80s and older: experience in the Japanese super-aged era.

Background: Demographic data of patients with sensorineural hearing loss (SNHL) in super-aged societies are still limited.Aims/objectives: To report audiometric statistics of SNHL and hearing aid (HA) use in patients in their 60s, 70s, and 80s and older during the super-aged era.Material and methods: Medical charts and audiograms of 2064 older patients with SNHL who visited a Japanese University Hospital in 2007-2018 were retrospectively reviewed. Among 270 patients referred to the HA service unit (HASU), the percentage of final decisions to continue using HAs was calculated.Results: The average pure tone thresholds on initial visit to the clinic were 56.9, 60.6, 69.4, and 82.4 dB HL in patients in their 60s, 70s, 80s, and 90s, respectively. The rates of progression were 0.25, 0.87, 1.19, and 1.37 dB/year in patients in their 50s, 60s, 70s, and 80s, respectively. The percentage of patients in HASU who chose to use HAs did not differ among the 60s (59.3%), 70s (51.2%), and 80s and older (58.2%).Conclusions and significance: The clinical picture of patients with SNHL in their 70s and 80s differs because progression accelerates exponentially through these ages. HAs can be recommended to older adult patients in all the age groups.

Impact of reading and writing skills on academic achievement among school-aged hearing-impaired children.

OBJECTIVES: Reading and writing skills are important for hearing-impaired children since these skills help them to develop their language skills, but the prevalence of reading/writing difficulties and its effects on language development aspects among them are unclear. In this study, we identified language development features and demographic factors of Japanese hearing-impaired children diagnosed as having reading/writing difficulties. METHODS: We analyzed data from a total of 546 sever-to-profound pre-school and elementary school hearing-impaired children for this study. Children with reading/writing difficulties (Group A) were defined as children obtaining low scores (-1.5 SD compared to others in the same grade) in the Screening Test of Reading and Writing for Japanese Primary School Children (STRAW), and we compared other language development features (communication ability, vocabulary, syntax and academic achievement) and demographic factors to those of hearing-impaired children with normal reading and writing skills (Group B). We assessed language development domains as outcomes using the Assessment of Language Development for Japanese Children (ALADJIN) package, and analyzed the results stratified by age groups (5-6, 7-8, 9-10, and 11-12 years) using multiple regression analyses. RESULTS: The prevalence of reading/writing difficulties was 20.1% among the participants. Almost all point estimates in each language development domain showed better odds ratios (OR) except Criterion Referenced Test -II (CRT-II) mathematics in 11- to 12-year-olds in fully-adjusted models. Among 9- to 10-year-olds, the ORs (95% confidence interval) for fair academic achievement measured by CRT-II were 2.60 (1.09-6.20) for Japanese and 3.02 (1.29-7.11) for mathematics in Group B, even after adjusting for possible confounding factors. CONCLUSIONS: Reading and writing are important for language development of hearing-impaired children, especially for academic achievement during the middle phase of elementary school. Screening for reading/writing difficulties is important for appropriate intervention and to prevent language and academic delays among hearing-impaired children.

OTOF mutation analysis with massively parallel DNA sequencing in 2,265 Japanese sensorineural hearing loss patients.

The OTOF gene (Locus: DFNB9), encoding otoferlin, is reported to be one of the major causes of non-syndromic recessive sensorineural hearing loss, and is also reported to be the most common cause of non-syndromic recessive auditory neuropathy spectrum disorder (ANSD). In the present study, we performed OTOF mutation analysis using massively parallel DNA sequencing (MPS). The purpose of this study was to reveal the frequency and precise genetic and clinical background of OTOF-related hearing loss in a large hearing loss population. A total of 2,265 Japanese sensorineural hearing loss (SNHL) patients compatible with autosomal recessive inheritance (including sporadic cases) from 53 otorhinolaryngology departments nationwide participated in this study. The mutation analysis of 68 genes, including the OTOF gene, reported to cause non-syndromic hearing loss was performed using MPS. Thirty-nine out of the 2,265 patients (1.72%) carried homozygous or compound heterozygous mutations in the OTOF gene. It is assumed that the frequency of hearing loss associated with OTOF mutations is about 1.72% of autosomal recessive or sporadic SNHL cases. Hearing level information was available for 32 of 39 patients with biallelic OTOF mutations; 24 of them (75.0%) showed profound hearing loss, 7 (21.9%) showed severe hearing loss and 1 (3.1%) showed mild hearing loss. The hearing level of patients with biallelic OTOF mutations in this study was mostly severe to profound, which is consistent with the results of past reports. Eleven of the 39 patients with biallelic OTOF mutations had been diagnosed with ANSD. The genetic diagnosis of OTOF mutations has significant benefits in terms of clinical decision-making. Patients with OTOF mutations would be good candidates for cochlear implantation; therefore, the detection of OTOF mutations is quite beneficial for patients, especially for those with ANSD.

Targeted PCR Array Analysis of Genes in Innate Immunity and Glucocorticoid Signaling Pathways in Mice Cochleae Following Acoustic Trauma.

AIM: To comprehensively analyze cochlear gene expressions related to innate immunity and glucocorticoid signaling at onset of acute noise-induced hearing loss (NIHL). BACKGROUND: Recent studies suggested innate immunity is involved in the cochlear pathology of NIHL. Glucocorticoids may modulate immune actions in cochleae. METHODS: Mice were exposed to 120 dB-octave band noise for 2 hours. Twelve hours later, a targeted PCR array analyzed cochlear expressions of 84 key genes in inflammation and immune pathways and 84 genes in the glucocorticoid signaling pathway. Real-time RT-PCR was used to analyze expression of two immune-related genes, Ccl12 and Glycam1, in noise-exposed cochleae with or without dexamethasone. RESULT: In inflammatory and immune gene pathways, 31.0% (26/84 genes) were significantly upregulated (>2-fold change) or downregulated (<0.5-fold change) (p < 0.05) in noise-exposed cochleae compared with controls. Sixteen of these differentially expressed genes (DEGs) encoded chemokines. DEGs included Ccl12, Ccl2, Ccl4, Ccl7, Cxcl1, Cxcl10, and Ptgs2 (upregulated genes), and Ccr7, Cxcr2, Kng1, Ltb, and Tnfsf14 (downregulated genes). In the glucocorticoid signaling pathway, 92.9% (78/84 genes) were unchanged in noise-exposed cochleae without dexamethasone administration. Cochlear expressions of Ccl12 and Glycam1 were significantly upregulated by noise and downregulated by dexamethasone. CONCLUSION: The targeted PCR array demonstrated that several dozen genes involved in innate immunity are actively regulated in cochleae with NIHL. The glucocorticoid signaling pathway was not endogenously regulated at 12 hours post-noise trauma. Systemic dexamethasone downregulated Ccl12 and Glycam1, which are upregulated in noise-exposed cochleae. These data may provide a basis for genomic medicine treatment of acute sensorineural hearing loss.

WFS1 mutation screening in a large series of Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis.

A heterozygous mutation in the Wolfram syndrome type 1 gene (WFS1) causes autosomal dominant nonsyndromic hereditary hearing loss, DFNA6/14/38, or Wolfram-like syndrome. To date, more than 40 different mutations have been reported to be responsible for DFNA6/14/38. In the present study, WFS1 variants were screened in a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA6/14/38 and Wolfram-like syndrome. Massively parallel DNA sequencing of 68 target genes was performed in 2,549 unrelated Japanese HL patients to identify genomic variations responsible for HL. The detailed clinical features in patients with WFS1 variants were collected from medical charts and analyzed. We successfully identified 13 WFS1 variants in 19 probands: eight of the 13 variants were previously reported mutations, including three mutations (p.A684V, p.K836N, and p.E864K) known to cause Wolfram-like syndrome, and five were novel mutations. Variants were detected in 15 probands (2.5%) in 602 families with presumably autosomal dominant or mitochondrial HL, and in four probands (0.7%) in 559 sporadic cases; however, no variants were detected in the other 1,388 probands with autosomal recessive or unknown family history. Among the 30 individuals possessing variants, marked variations were observed in the onset of HL as well as in the presence of progressive HL and tinnitus. Vestibular symptoms, which had been rarely reported, were present in 7 out of 30 (23%) of the affected individuals. The most prevalent audiometric configuration was low-frequency type; however, some individuals had high-frequency HL. Haplotype analysis in three mutations (p.A716T, p.K836T, and p.E864K) suggested that the mutations occurred at these mutation hot spots. The present study provided new insights into the audiovestibular phenotypes in patients with WFS1 mutations.

Relationship between pure-tone audiogram findings and speech perception among older Japanese persons.

OBJECTIVE: To clarify how the pure-tone threshold (PTT) on the PTA predicts speech perception (SP) in elderly Japanese persons. METHODS: Data on PTT and SP were cross-sectionally analyzed in Japanese persons (656 ears in 353 patients, aged ≥65 years). Correlations of SP and average PTT in all tested frequencies were evaluated by Pearson's correlation coefficient and simple linear regression. After adjusting for sex, laterality of ears, and age, the relationship of average and frequency-specific PTT with impaired SP ≤50% was estimated by logistic regression models. RESULTS: SP correlated well (r = -0.699) with the average PTT of all tested frequencies. On the other hand, the correlation between patient age and SP was weak, especially among ≤85-year-old persons (r = -0.092). Linear regression showed that the average PTT corresponding to SP of 50% was 76.4 dB nHL. Odds ratios for impaired SP were highest for PTT at 2000 Hz. Odds ratios were higher for middle (500, 1000, 2000 Hz) and high frequencies (4000, 8000 Hz) than low frequencies (125, 250 Hz). CONCLUSION: The PTT on the pure-tone audiogram (PTA) is a good predictor of SP by speech audiometry among older persons, which could provide clinically important information for hearing aid fitting and cochlear implantation.

Cochlear Transcriptome Following Acoustic Trauma and Dexamethasone Administration Identified by a Combination of RNA-seq and DNA Microarray.

AIM: To elucidate molecular mechanisms of noise-induced hearing loss (NIHL) and glucocorticoid therapy in the cochlea. BACKGROUND: Glucocorticoids are used to treat many forms of acute sensorineural hearing loss, but their molecular action in the cochlea remains poorly understood. METHODS: Dexamethasone was administered intraperitoneally immediately following acoustic overstimulation at 120 dB SPL for 2 hours to mice. The whole cochlear transcriptome was analyzed 12 and 24 hours following noise trauma and dexamethasone administration by both next-generation sequencing (RNA-seq) and DNA microarray. Differentially expressed genes (DEGs) with more than 2-fold changes after noise trauma and dexamethasone administration were identified. The functions of these DEGs were analyzed by David Bioinformatics Resources and a literature search. RESULTS: Twelve hours after acoustic overstimulation, immune-related gene pathways such as "chemokine signaling activity," "cytokine-cytokine receptor interaction," and "cell adhesion molecules (CAMs) in the immune system" were significantly changed compared with the baseline level without noise. These DEGs were involved in immune and defense responses in the cochlea. Dexamethasone was administered to this NIHL model, and it modulated gene pathways of "cytokine-cytokine receptor interaction" and "cell adhesion molecules (CAMs) in the immune system" at 12 hours, compared with saline-injected control. Dexamethasone-dependent DEGs were also involved in immune and defense responses. A literature search showed that 10 other genes associated with hearing functions were regulated by dexamethasone both at 12 and 24 hours post-administration. CONCLUSION: Dexamethasone modulates the immune reaction in the traumatized cochlea following acoustic overstimulation. Dexamethasone may also regulate cochlear functions other than immunity.

Genetic Counseling of a Hearing-impaired Patient with Multiple Genetic Mutations.

Since April 2012, genetic testing for congenital hearing loss is covered by the public health insurance in Japan. Recent (since August 2015) developments in next-generation sequencing technology have enabled the detection of 154 mutations in 19 genes. Genetic testing provides valuable information on hearing phenotype, prognosis, and prediction of associated symptoms. We report a hearing-impaired patient in whom multiple genetic mutations were detected. This patient carries two missense mutations in GJB2 (p.G45E, p.Y136X), as well as a mitochondrial mutation (7445A>G). Since the number of genes detectable by genetic testing has increased, the diagnosis of hearing loss can be made with greater accuracy. However, it is often difficult to clinically understand and interpret the genotype information, especially when multiple gene variants are detected in one patient or family. Genetic counseling plays an important part in the intervention for or follow-up of such patients. Genotypic and phenotypic information of other family members is necessary, so that both the patient and the family can understand and accept the results of genetic testing.

Subjective hearing-related quality-of-life is a major factor in the decision to continue using hearing aids among older persons.

CONCLUSION: Audiological parameters alone do not determine the choice to use hearing aids (HA). Subjective hearing-related QoL is a major factor that determines whether or not an older person will continue to wear HA. OBJECTIVE: This study aimed to identify which audiological parameters and quality-of-life (QoL) measures determine whether or not older persons will continue wearing HA. METHODS: Charts of 157 patients aged ≥65 years who attended the HA service unit at the Otolaryngology Department were retrospectively reviewed. After HA fitting and a trial, the patients were divided into groups, depending upon whether or not they wanted to continue wearing the HA (users, 58.2%; non-users, 41.8%) and then audiological parameters were compared between them. At least 4 months after the HA fitting, the self-reported QoL questionnaire, Hearing Handicap Inventory for the Elderly (HHIE), was mailed to all 157 patients and HHIE scores were compared between HA users and non-users. RESULT: Speech discrimination score and dynamic range did not significantly differ between HA users and non-users. A difference in the average hearing threshold was marginally significant. The response rate to the HHIE was 65.2%. Total HHIE and emotional scores were higher (more impaired) among HA users than non-users.

Pediatric central auditory processing disorder showing elevated threshold on pure tone audiogram.

Central auditory processing disorder (CAPD) is a condition in which dysfunction in the central auditory system causes difficulty in listening to conversations, particularly under noisy conditions, despite normal peripheral auditory function. Central auditory testing is generally performed in patients with normal hearing on the pure tone audiogram (PTA). This report shows that diagnosis of CAPD is possible even in the presence of an elevated threshold on the PTA, provided that the normal function of the peripheral auditory pathway was verified by distortion product otoacoustic emission (DPOAE), auditory brainstem response (ABR), and auditory steady state response (ASSR). Three pediatric cases (9- and 10-year-old girls and an 8-year-old boy) of CAPD with elevated thresholds on PTAs are presented. The chief complaint was difficulty in listening to conversations. PTA showed elevated thresholds, but the responses and thresholds for DPOAE, ABR, and ASSR were normal, showing that peripheral auditory function was normal. Significant findings of central auditory testing such as dichotic speech tests, time compression of speech signals, and binaural interaction tests confirmed the diagnosis of CAPD. These threshold shifts in PTA may provide a new concept of a clinical symptom due to central auditory dysfunction in CAPD.

Characteristics of audiogram configuration in multiple-system atrophy C and cortical cerebellar atrophy.

CONCLUSION: The prevalence of low-tone hearing loss (LTHL) is significantly high in spinocerebellar degeneration (SCD) with cerebellar predominance, including multiple-system atrophy C (MSA-C) and cortical cerebellar atrophy (CCA). OBJECTIVE: This study aimed to test the hypothesis that SCD with cerebellar predominance, MSA-C and CCA may cause auditory symptoms. METHODS: The shape and threshold of pure-tone audiograms were evaluated for MSA-C (n = 47; mean (± SD) age, 61.6 ± 8.9 years), CCA (n = 16; 62.8 ± 9.5 years), and age-matched controls (n = 169; 62.5 ± 10.7 years). To differentiate specific hearing loss for MSA-C and CCA from presbycusis, the shape of audiograms was examined based on previously established audiological criteria. RESULTS: When audiogram shape was defined according to audiological criteria, the odds ratio for LTHL in SCD compared to controls was 2.492 (95% confidence interval (CI) = 1.208-5.139; p < 0.05, Pearson's Chi-square test) in MSA-C and 2.194 (95% CI = 0.709-6.795) in CCA. When the selection of audiogram shape according to these criteria was verified by three certified audiologists, odds ratios for LTHL in MSA-C and CCA were 3.243 (95% CI = 1.320-7.969) and 3.692 (95% CI = 1.052-12.957), respectively, significantly higher than in controls.