Synaptic ribbon dynamics after noise exposure in the hearing cochlea.

Moderate noise exposure induces cochlear synaptopathy, the loss of afferent ribbon synapses between cochlear hair cells and spiral ganglion neurons, which is associated with functional hearing decline. Prior studies have demonstrated noise-induced changes in the distribution and number of synaptic components, but the dynamic changes that occur after noise exposure have not been directly visualized. Here, we describe a live imaging model using RIBEYE-tagRFP to enable direct observation of pre-synaptic ribbons in mature hearing mouse cochleae after synaptopathic noise exposure. Ribbon number does not change, but noise induces an increase in ribbon volume as well as movement suggesting unanchoring from synaptic tethers. A subgroup of basal ribbons displays concerted motion towards the cochlear nucleus with subsequent migration back to the cell membrane after noise cessation. Understanding the immediate dynamics of synaptic damage after noise exposure may facilitate identification of specific target pathways to treat cochlear synaptopathy.

Differences in Hearing Devices and Speech Therapy Utilization Between Children With Permanent Unilateral Versus Bilateral Hearing Loss.

OBJECTIVES: In this study, we aimed to describe differences in diagnosis and both auditory and speech/language intervention utilization between children with permanent unilateral hearing loss as compared with bilateral hearing loss. DESIGN: A retrospective cohort study was performed of children evaluated in a multidisciplinary hearing loss clinic at a tertiary care pediatric hospital. Children aged 0 to 18 years with either permanent unilateral or bilateral hearing loss were included. RESULTS: One hundred fourteen children with unilateral hearing loss and 268 children with bilateral hearing loss were studied for a total of 382 children. There were no demographic differences between children with permanent unilateral versus bilateral hearing loss. Rates of newborn hearing screening and referred screening results were similar between those with unilateral and bilateral hearing loss. Despite similar rates of referred newborn hearing screening, those with bilateral hearing loss were diagnosed at a younger age (mean 3.6 years, SD 3.8 years) as compared with those with unilateral hearing loss (mean 5.0 years, SD 4.2 years). Children with unilateral hearing loss had similar severity of hearing loss in their poorer hearing ear as compared with children with bilateral hearing loss, yet they were significantly less likely to be fitted with hearing devices (53% versus 78%) or receive speech/language therapy (36% versus 54%) as compared with children with bilateral hearing loss. Multivariate analysis found that bilateral hearing loss and earlier age of hearing loss diagnosis were associated with hearing device use. CONCLUSIONS: Early diagnosis and intervention for childhood hearing loss have a significant impact on a child's educational success and social relationships. However, little is known about differences in diagnosis and resource utilization between children with permanent unilateral hearing loss versus bilateral hearing loss. Children with unilateral hearing loss were diagnosed at a later age and were less likely to utilize hearing devices or speech/language therapy compared with those with bilateral hearing loss, despite having similar severity of hearing loss in the poorer hearing ear. There is a strong body of evidence that children with unilateral hearing loss have improved hearing outcomes with hearing devices, which suggests there is room for improvement in identifying unilateral hearing loss and providing adequate services to optimize educational success. However, speech therapy is generally implemented in response to language delays. Therefore, children with unilateral loss may have lower rates of language delays as compared with those with bilateral hearing loss, thereby explaining differences in speech therapy utilization.

Diagnostic Utility of Parent Ratings on the Behavior Assessment System for Children-Third Edition in Children who are Deaf and Hard of Hearing and Diagnosed with Autism Spectrum Disorder.

Between 1 to 2 of every 1,000 children are born deaf or hard of hearing (DHH) and, of those, 30-50% have additional disabilities, including Autism Spectrum Disorder (ASD). Most measures assessing ASD characteristics rely on some degree of behavioral response to sound (e.g., responding to name, listening response), and may not be appropriate for use with children who are DHH. Further, ASD specific measures do not provide information on a child's functional abilities across developmental domains. We conducted a cross-sectional analysis comparing mean T-scores on a standardized multidimensional measure, the Behavior Assessment System for Children, Third Edition, Parent Rating Scale (BASC-3 PRS), across three groups matched for age and sex: children who are DHH and diagnosed with ASD (DHH + ASD; n = 16); children who are DHH without ASD (DHH-ASD; n = 16); and children who are typically hearing with ASD (H + ASD; n = 16). Analyses revealed statistically significant differences across scales of Attention Problems, Atypicality, Withdrawal, Behavioral Symptoms Index, Social Skills, Leadership, Functional Communication, Activities of Daily Living, Adaptive Skills, Autism Probability Indices, and Developmental Social Disorders. Pairwise comparisons showed DHH + ASD and H + ASD mean T-scores were statistically similar and distinct from DHH-ASD mean T-scores on all these scales except for Withdrawal, Leadership, Functional Communication, and Activities of Daily Living, where pairwise comparisons varied. The findings add to the literature on ASD and DHH children and call for further exploration of the BASC-3 as a tool for both evaluation of ASD and the development of individualized treatment plans in this unique population.

Factors associated with congenital cytomegalovirus infection detected by dried blood spot testing in children with hearing loss.

OBJECTIVE: Congenital cytomegalovirus (cCMV) infection in infants leads to an increased risk of developing sensorineural hearing loss (SNHL), even if they are asymptomatic at birth. There are currently no national guidelines for universal screening for CMV, placing children with cCMV at a high risk for unidentified and untreated HL, which in turn places them at greater risk for lasting impacts on quality of life and cognitive and behavioral abilities. We sought to describe the sociodemographic and hearing loss characteristics of children with HL due to cCMV. DESIGN: We performed a retrospective cohort study of patients 0-18 years of age who completed CMV dried blood spot (DBS) testing in our HL clinic before April 1, 2022. Home ZIP codes were entered into the Healthy Places Index (HPI) database to quantify the health of the community in which the patient lived. Severity of HL was determined by pure tone averages (PTA) of hearing thresholds for frequencies of 500Hz, 1000Hz, 2000Hz, and 4000Hz. Progression was defined as those who referred on newborn hearing screen and then had a >15 dB increase in PTA, and those who passed newborn hearing screen and were found to have HL later in life. Logistic regression was used to compare variables. RESULTS: Of 365 children who received a CMV DBS test, 15 (4%) had a positive test, indicating the presence of cCMV infection, and 350 (96%) had a negative test. 192 (53%) were male, 212 (58%) were URM, 202 (55%) had public insurance, the median number of ICD-10 codes was 2 (range 0-53), and the median HPI percentile score was 71.2 (range: 3.4-99.9). Although CMV DBS testing was ordered for those with suspicion of SNHL, ultimately diagnostic testing found 333 (91%) with SNHL, 4 (1%) with CHL, 13 (4%) with mixed HL, 9 (3%) with auditory neuropathy spectrum disorder, and 5 (4%) with unspecified HL, and 11 (3%) without HL. Of the 353 patients with HL, 126 (36%) had unilateral, 156 (44%) had symmetric bilateral, and 71 (20%) had asymmetric bilateral HL; 183 (52%) had progressive and 138 (39%) had stable HL. In children with SNHL (n = 333), we tested the association of socio-demographic and audiologic factors with cCMV. Those with asymmetric bilateral SNHL (OR 5.19, 95% CI 1.81-14.90) or profound SNHL (>90 dB) in either ear (OR 13.91, 95% CI 3.82-50.67) had higher odds of having cCMV. Those with symmetric bilateral SNHL had lower odds of a positive CMV DBS test result (OR 0.17, 95% CI 0.02-0.76). All sociodemographic variables, medical comorbidities, and other audiologic variables were not associated with CMV DBS test results. CONCLUSION: Congenital CMV infection is associated with asymmetric bilateral and profound SNHL. More research is warranted to determine best practices for universal screening for cCMV to identify these children.

Predictors of successful natural sleep MRI for sensorineural hearing loss in infants.

OBJECTIVES: Cochlear implantation (CI) in children with sensorineural hearing loss (SNHL) before 12 months of age (mo) improves language outcomes. MRI is important to assess CI candidacy. Anesthesia before 3 years old may increase risk of neurocognitive delay. Natural sleep MRI (NS-MRI) is an emerging technique to avoid anesthesia in infants, but relies on successful sleep for adequate imaging. Our multidisciplinary team hypothesized the following predictors of successful NS-MRI for CI evaluation: age, distance travelled, comorbidities, primary language, insurance type, HL characteristics, time and duration of MRI. METHODS: We performed retrospective review of children 0-12mo who attempted NS-MRI. The NS-MRI was successful if imaging was sufficient for definitive clinical management per the managing otolaryngologist. RESULTS: Among 26 patients (29 scans), the median age was 3.2mo (range: 1.2-6.8mo), distance travelled was 16.3 miles (range: 0.9 to 365 miles), 12 (46%) children had medical comorbidities. 8 (31%) had public insurance. 10 (38%) had bilateral HL. 52% (15/29) of scans were successful. Patients with comorbidities had significantly lower odds of successful NS-MRI (OR 0.09; 95% CI 0.01-0.54). Success was not associated with age, distance travelled, insurance type, primary language, HL characteristics, time or duration of MRI on univariable analysis. All 11 children who failed NS-MRI underwent hearing-aid fitting and/or imaging with sedation and CI as clinically indicated before 12mo. CONCLUSION: NS-MRI was successful in 52% of infants, regardless of age, demographics, HL or MRI characteristics. Unsuccessful NS-MRI did not result in delayed intervention. NS-MRI is an effective consideration for a broad range of infants with SNHL.

Outcomes of Gene Panel Testing for Sensorineural Hearing Loss in a Diverse Patient Cohort.

Importance: A genetic diagnosis can help elucidate the prognosis of hearing loss, thus significantly affecting management. Previous studies on diagnostic yield of hearing loss genetic tests have been based on largely homogenous study populations. Objectives: To examine the diagnostic yield of genetic testing in a diverse population of children, accounting for sociodemographic and patient characteristics, and assess whether these diagnoses are associated with subsequent changes in clinical management. Design, Setting, and Participants: This retrospective cohort study included 2075 patients seen at the Children's Communications Clinic, of whom 517 completed hearing loss gene panel testing between January 1, 2015, and November 1, 2021, at the University of California, San Francisco Benioff Children's Hospital system. From those 517 patients, 426 children with at least 2 audiograms were identified and analyzed. Data were gathered from November 2021 to January 2022 and analyzed from January to February 2022. Main Outcomes and Measures: The measures of interest were sociodemographic characteristics (age at testing, gender, race and ethnicity, primary language, and insurance type), hearing loss characteristics, and medical variables. The outcome was genetic testing results. Variables were compared with univariate and multivariable logistic regression. Results: Of the 2075 patients seen at the Children's Communications Clinic, 517 (median [range] age, 8 [0-31] years; 264 [51.1%] male; 351 [67.9%] from an underrepresented minority [URM] group) underwent a hearing loss panel genetic test between January 1, 2015, and November 1, 2021. Among those 517 patients, 426 children (median [range] age, 8 [0-18] years; 221 [51.9%] male; 304 [71.4%] from an URM group) with 2 or more audiograms were included in a subsequent analysis. On multivariable logistic regression, age at testing (odds ratio [OR], 0.87; 95% CI, 0.78-0.97), URM group status (OR, 0.29; 95% CI, 0.13-0.66), comorbidities (OR, 0.27; 95% CI, 0.14-0.53), late-identified hearing loss (passed newborn hearing screen; OR, 0.27; 95% CI, 0.08-0.86), and unilateral hearing loss (OR, 0.04; 95% CI, 0.005-0.33) were the only factors associated with genetic diagnosis. No association was found between genetic diagnosis yield and other sociodemographic variables or hearing loss characteristics. Patients in URM and non-URM groups had statistically similar clinical features. A total of 32 of 109 children (29.4%) who received a genetic diagnosis received diagnoses that significantly affected prognosis because of identification of syndromic or progressive sensorineural hearing loss or auditory neuropathy spectrum disorder relating to otoferlin. Conclusions and Relevance: This cohort study's findings suggest that genetic testing may be broadly useful in improving clinical management of children with hearing loss. More research is warranted to discover and characterize diagnostic genes for those who have been historically underrepresented in research and medicine.

Racial and ethnic disparities in genetic testing for hearing loss: a systematic review and synthesis.

Racial/ethnic disparities in the diagnostic efficacy of genetic testing for hearing loss have been described. These disparities may relate to differences in variant classification between different racial/ethnic groups, which may, in turn, derive from disparate representation of these groups in the published literature. We sought to quantify racial/ethnic disparities in the published literature on the human genetics of hearing loss. We conducted a search of PubMed for articles describing single-gene, multiple-gene, or whole-exome sequencing for individuals with sensorineural hearing loss. Data on the included subjects, including race/ethnicity and/or region of origin, a number of subjects tested, and method of testing, were extracted. 1355 populations representing 311,092 subjects from 1165 studies were included. Overall, subjects of European and Asian ancestry were equivalently represented, but those of Latino American, African, and indigenous North American ancestry were significantly underrepresented; over 96% of all subjects in the published literature were European or Asian. Within populations, the majority of subjects derived from a small subset of countries. The observed disparity was greater for multiple-gene and whole-exome sequencing than for single-gene sequencing. These findings illustrate the large disparity in the published literature on the genetics of hearing loss, and demonstrate the need for increased representation of Latino American, African, and indigenous North American populations.