Congenital Sensorineural Hearing Loss Research Articles

Testing for genetic and viral etiologies in congenital hearing loss based on a survey of cochlear implant centers: proposed HEARRING group consensus and future directions

Background In cases of congenital sensorineural hearing loss, testing for genetic etiologies and congenital cytomegalovirus (cCMV) infection have become common practice. Aims/Objectives The purpose of this study is to determine which specific testing methodologies should be used and when. Material and methods We surveyed 20 practicing otolaryngologists across eighteen institutions in thirteen countries about their approach to cCMV, GJB2, and wider genetic testing. Results We found 90% of respondents employ all three tests, either in routine or special cases. cCMV testing is widely used, with 95% of respondents incorporating it into their clinical practice. GJB2 testing was employed by 90%. In cases with negative GJB2 test results, a majority of respondents proceeded to wider genetic screening. Test reimbursement was also examined for each test. For cCMV testing, 63.1% reported reimbursement, 68.4% reported reimbursement for GJB2 variant testing and 52.6% reported reimbursement for wider genetic screening. Conclusions and significance A common approach is to perform cCMV and GJB2 testing as the first tests, followed by wider genetic testing. This study offers insight into the prevalence, methodologies, and reimbursement status of these testing methodologies across multiple hearing centers and countries. Current consensus and future directions are described based on the current survey.

Identification of a novel FGF3 variant and a new phenotype in three LAMM syndrome families

Over 700 syndromes associated with hearing loss (HL) have been identified. Labyrinthine aplasia, microtia, and microdontia (LAMM syndrome, OMIM: 610706) is a rare HL syndrome characterized by congenital sensorineural HL, labyrinthine aplasia, type I microtia and microdontia, which is caused by biallelic variants in the FGF3 gene. Using Whole-exome sequencing (WES), we identified a novel missense FGF3 variant (c.137G > C, p. Arg46Pro (NM_005247.4) in three unrelated Uyghur ethnic families. This variant is classified as a variant of uncertain significance according to ACMG guidelines, with the applied criteria of PM3, PM2_Supporting, PP3 and PP4. Patients from the three families revealed variable clinical features. We found a novel phenotype, sparse hair, in one of the proband. Our findings expanded the variant and phenotype spectrum of LAMM syndrome and provided new insights to the diagnose and pathogenesis investigation of the disease.

Glymphatic System Dysfunction in Congenital Sensorineural Hearing Loss: A DTI-ALPS Study

The neural mechanisms underlying congenital sensorineural hearing loss (CSNHL) remain elusive. This study evaluated the function of the glymphatic system in children with CSNHL compared to normal-hearing children using the DTI-ALPS approach, which utilizes diffusion tensor imaging along the perivascular space. Twenty-six children with CSNHL and 30 age- and sex-matched healthy controls (HCs) with normal hearing thresholds were recruited. The DTIALPS index was calculated for each group. We analyzed the discrepancies in the DTI-ALPS index between patients with CSNHL and healthy controls. Additionally, Spearman's correlation analysis was performed to investigate the relationship between the DTI-ALPS index and age in children with CSNHL. Significant differences in the DTI-ALPS index were observed between the two groups. Compared with HCs, the DTI-ALPS index in CSNHL patients was significantly lower (1.49388±0.11441 vs. 1.61402±0.15430, p=0.002). In addition, diffusivity along the z-axis in the association fiber (Dzzassoc) index was significantly higher in the CSNHL group than in the HC group (0.00041±0.00006 vs. 0.00036±0.00004, p=0.003). Furthermore, we discovered a noteworthy downward correlation between the DTI-ALPS index and age in children with CSNHL (rho = -0.544, p=0.005). In this present study, glymphatic system activity in CSNHL children was investigated for the first time using the DTI-ALPS index. A significant decrease in glymphatic system function was detected in CSNHL children, which correlated well with age. The DTI-ALPS index could serve as a valuable biomarker for tracking disease progression and treatment in CSNHL and unraveling the neural mechanisms of early hearing deprivation in children with CSNHL.

Dynamic functional network connectivity in children with profound bilateral congenital sensorineural hearing loss.

Functional magnetic resonance imaging (fMRI) studies have revealed extensive functional reorganization in patients with sensorineural hearing loss (SNHL). However, almost no study focuses on the dynamic functional connectivity after hearing loss. This study aimed to investigate dynamic functional connectivity changes in children with profound bilateral congenital SNHL under the age of 3years. Thirty-two children with profound bilateral congenital SNHL and 24 children with normal hearing were recruited for the present study. Independent component analysis identified 18 independent components composing five resting-state networks. A sliding window approach was used to acquire dynamic functional matrices. Three states were identified using the k-means algorithm. Then, the differences in temporal properties and the variance of network efficiency between groups were compared. The children with SNHL showed longer mean dwell time and decreased functional connectivity between the auditory network and sensorimotor network in state 3 (P < 0.05), which was characterized by relatively stronger functional connectivity between high-order resting-state networks and motion and perception networks. There was no difference in the variance of network efficiency. These results indicated the functional reorganization due to hearing loss. This study also provided new perspectives for understanding the state-dependent connectivity patterns in children with SNHL.

Novel GJB2 mutation c.188delT compound with c.235delC causing non-syndromic hearing loss in a Chinese family: A case report.

Congenital sensorineural hearing loss is a significant global health issue, primarily driven by genetic factors, such as mutations in the GJB2 gene. This report presents a Chinese girl with congenital deafness and a novel mutation of the GJB2 gene. A newborn Chinese girl exhibited signs of congenital deafness. Congenital deafness was confirmed through comprehensive newborn hearing screenings that included otologic, audiologic, and physical examinations. Genetic analysis revealed a compound heterozygous mutation involving c.188delT and c.235delC in the GJB2 gene, indicating a genetic basis for her hearing loss. The patient underwent cochlear implantation, which resulted in stable auditory outcomes. Despite follow-up difficulties, stable auditory outcomes were achieved post-cochlear implantation, highlighting the potential efficacy of this intervention in GJB2-related hearing loss. This case study enriches our understanding of GJB2 mutations and underscores the critical role of genetic testing in diagnosing congenital sensorineural hearing loss. It emphasizes the necessity for early intervention and sustained interdisciplinary care to enhance the quality of life for patients with genetic hearing impairment.

A novel compound heterozygous variant of MYO7A in Usher syndrome type 1

Usher syndrome (USH) is a recessive genetic disorder manifested by congenital sensorineural hearing loss and progressive retinitis pigmentosa, which leads to audiovisual impairment. We report a patient with Usher syndrome type 1 with new compound heterozygous MYO7A variants. A total of four members from the USH family were included. Medical history and retinal examinations were taken and genomic DNA from peripheral blood was extracted in the proband and other members. 381 retinal disease-associated genes were screened using targeted sequence capture array technology and Sanger sequencing was used to confirm the screening results. Scanning laser ophthalmoscope showed bone spicule pigmentary deposits in the mid-peripheral retina and whitish and thin retinal blood vessels especially in the arterioles. Optical coherence tomography showed that the centrality of the macular ellipsoid band disappeared in both eyes, and only remained near the fovea. Visual field examination showed a progressive loss of the visual field in a concentric pattern in both eyes. The electroretinography showed a significant decrease in the amplitudes of a- and b-waves in the scotopic and photopic condition. DNA sequencing identified the compound heterozygous variants including c.1003+1G > A: p. (?) and c.5957_5958del: p.G1987Lfs*50 of MYO7A, with the latter being novel. In this study, we found a novel compound heterozygous variant in MYO7A, which enriched the mutation spectrum and expanded our understanding of the heterogeneity of phenotype and genotype of Usher syndrome type 1.

Evaluation of automatic cochlear dimension measurement using ALPACA: a comparative study

Background Cochlear dimension measurements are critical in diagnosing and managing congenital sensorineural hearing loss. Objectives To evaluate the feasibility and reliability of an automated landmark approach for measuring cochlear dimensions (A-, B- and H-values). Material and Methods Cochlear parameters from 100 patients were measured by MPR, manual three-dimensional and ALPACA. We assessed intra- and inter-observer reliability as well as inter-method reliability. Statistical analyses were conducted to detect differences between the right and left ears, as well as to assess the relevance of the values obtained using ALPACA. Results All A-, B-, and H-values measured by the various methods showed a high intra-observer reliability with intra-class correlation coefficients (ICC) ranging from 0.70 to 0.99, and values gained by ALPACA reaching the highest ICC. Inter-method reliability was at a good level with ICC ranging from 0.51 to 0.86. There were no significant differences between the right and left ears’ measured values. Obvious positive correlations existed among cochlear dimensions measured by ALPACA. Conclusions and Significance The ALPACA method can be used to measure cochlear dimensions. Values obtained by the method demonstrate high reliability and consistency with a significant reduction in intra-observer variability compared to results from conventional MPR and manual 3D measurements.

A large-scale screening identified in USH2A gene the P3272L founder pathogenic variant explaining familial Usher syndrome in Sardinia, Italy

BackgroundUsher syndrome (USH) encompasses a group of disorders characterized by congenital sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP). We described the clinical findings, natural history, and molecular analyses of USH patients identified during a large-scale screening to identify quantitative traits related to ocular disorders in the SardiNIA project cohort.MethodsWe identified 3 USH-affected families out of a cohort of 6,148 healthy subjects. 9 subjects presented a pathological phenotype, with SNHL and RP. All patients and their family members underwent a complete ophthalmic examination including best-corrected visual acuity, slit-lamp biomicroscopy, fundoscopy, fundus autofluorescence, spectral-domain optical coherence tomography, and electrophysiological testing. Audiological evaluation was performed with a clinical audiometer. Genotyping was performed using several arrays integrated with whole genome sequence data providing approximately 22 million markers equally distributed for each subject analyzed. Molecular diagnostics focused on analysis of the following candidate genes: MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, GPR98, DFNB31, CLRN1, and PDZD7.ResultsA single missense causal variant in USH2A gene was identified in homozygous status in all patients and in heterozygous status in unaffected parents. The presence of multiple homozygous patients with the same phenotypic severity of the syndromic form suggests that the Sardinian USH phenotype is the result of a founder effect on a specific pathogenic variant related haplotype. The frequency of heterozygotes in general Sardinian population is 1.89. Additionally, to provide new insights into the structure of usherin and the pathological mechanisms caused by small pathogenic in-frame variants, like p.Pro3272Leu, molecular dynamics simulations of native and mutant protein–protein and protein–ligand complexes were performed that predicted a destabilization of the protein with a decrease in the free energy change.ConclusionsOur results suggest that our approach is effective for the genetic diagnosis of USH. Based on the heterozygous frequency, targeted screening of this variant in the general population and in families at risk or with familial USH can be suggested. This can lead to more accurate molecular diagnosis, better genetic counseling, and improved molecular epidemiology data that are critical for future intervention plans.Trial registrationWe did not perform any health-related interventions for the participants.

Long-Term Outcomes of Cochlear Implantation in Usher Syndrome.

Usher syndrome (USH), characterized by bilateral sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP), prompts increased reliance on hearing due to progressive visual deterioration. It can be categorized into three subtypes: USH type 1 (USH1), characterized by severe to profound congenital SNHL, childhood-onset RP, and vestibular areflexia; USH type 2 (USH2), presenting with moderate to severe progressive SNHL and RP onset in the second decade, with or without vestibular dysfunction; and USH type 3 (USH3), featuring variable progressive SNHL beginning in childhood, variable RP onset, and diverse vestibular function. Previous studies evaluating cochlear implant (CI) outcomes in individuals with USH used varying or short follow-up durations, while others did not evaluate outcomes for each subtype separately. This study evaluates long-term CI performance in subjects with USH, at both short-term and long-term, considering each subtype separately. This retrospective, observational cohort study identified 36 CI recipients (53 ears) who were categorized into four different groups: early-implanted USH1 (first CI at ≤7 years of age), late-implanted USH1 (first CI at ≥8 years of age), USH2 and USH3. Phoneme scores at 65 dB SPL with CI were evaluated at 1 year, ≥2 years (mid-term), and ≥5 years postimplantation (long-term). Each subtype was analyzed separately due to the significant variability in phenotype observed among the three subtypes. Early-implanted USH1-subjects (N = 23 ears) achieved excellent long-term phoneme scores (100% [interquartile ranges {IQR} = 95 to 100]), with younger age at implantation significantly correlating with better CI outcomes. Simultaneously implanted subjects had significantly better outcomes than sequentially implanted subjects ( p = 0.028). Late-implanted USH1 subjects (N = 3 ears) used CI solely for sound detection and showed a mean phoneme discrimination score of 12% (IQR = 0 to 12), while still expressing satisfaction with ambient sound detection. In the USH2 group (N = 23 ears), a long-term mean phoneme score of 85% (IQR = 81 to 95) was found. Better outcomes were associated with younger age at implantation and higher preimplantation speech perception scores. USH3-subjects (N = 7 ears) achieved a mean postimplantation phoneme score of 71% (IQR = 45 to 91). This study is currently one of the largest and most comprehensive studies evaluating CI outcomes in individuals with USH, demonstrating that overall, individuals with USH benefit from CI at both short- and long-term follow-up. Due to the considerable variability in phenotype observed among the three subtypes, each subtype was analyzed separately, resulting in smaller sample sizes. For USH1 subjects, optimal CI outcomes are expected with early simultaneous bilateral implantation. Late implantation in USH1 provides signaling function, but achieved speech recognition is insufficient for oral communication. In USH2 and USH3, favorable CI outcomes are expected, especially if individuals exhibit sufficient speech recognition with hearing aids and receive ample auditory stimulation preimplantation. Early implantation is recommended for USH2, given the progressive nature of hearing loss and concomitant severe visual impairment. In comparison with USH2, predicting outcomes in USH3 remains challenging due to the variability found. Counseling for USH2 and USH3 should highlight early implantation benefits and encourage hearing aid use.

The Role of Computed Tomography in the Diagnosis of Congenital Sensorineural Hearing Loss.

Introduction One of the paths in the investigation of congenital sensorineural hearing loss (CSNHL) is to try to characterize its etiology through the inner ear evaluation using high resolution computer tomography (CT) scans. With minor malformation, it is not always possible for a simple visual inspection to recognize if the structure in the inner ear is normal or not. Objective To verify if measurements of the inner ear are predictive of sensorineural hearing loss (SNHL) and suggest cutoff points of size limits. Methods Retrospective cross-sectional study of inner ear CT scan measurements of 214 patients, 50 with congenital SNHL (CSNHL) and 164 acquired SNHL (ASNHL) (control group). Results In the CSNHL group, central bony island (CBI) were 0.48 mm smaller ( p < 0.001), cochlear nerve aperture was (CNA) 0.10 mm smaller ( p < 0.001), and cochlea height was (CH) 0.15 mm smaller ( p < 0.001). Vestibular aqueduct (VA) and cochlea width (CW) were similar between groups (0.70 vs 0.72, p = 0.19, and 7.20 vs 7.15 p = 0.23). The predictive cutoff points for CSNHL were CBI = 3.6 mm, CAN = 1.4 mm, CH = 3.4 mm, CW = 7.0 mm, and VA = 0.9 mm. Conclusion Congenital sensorineural hearing loss determined a decrease in CBI, opening of the cochlear nerve (OCN), and CW. Thus, these measures, at the cutoff points indicated, should make us aware of the diagnosis of congenital hearing loss.

Cerebral cortex functional reorganization in preschool children with congenital sensorineural hearing loss: a resting-state fMRI study.

How cortical functional reorganization occurs after hearing loss in preschool children with congenital sensorineural hearing loss (CSNHL) is poorly understood. Therefore, we used resting-state functional MRI (rs-fMRI) to explore the characteristics of cortical reorganization in these patents. Sixty-three preschool children with CSNHL and 32 healthy controls (HCs) were recruited, and the Categories of Auditory Performance (CAP) scores were determined at the 6-month follow-up after cochlear implantation (CI). First, rs-fMRI data were preprocessed, and amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were calculated. Second, whole-brain functional connectivity (FC) analysis was performed using bilateral primary auditory cortex as seed points. Finally, Spearman correlation analysis was performed between the differential ALFF, ReHo and FC values and the CAP score. ALFF analysis showed that preschool children with CSNHL had lower ALFF values in the bilateral prefrontal cortex and superior temporal gyrus than HCs, but higher ALFF values in the bilateral thalamus and calcarine gyrus. And correlation analysis showed that some abnormal brain regions were weak negatively correlated with CAP score (p < 0.05). The ReHo values in the bilateral superior temporal gyrus, part of the prefrontal cortex and left insular gyrus were lower, whereas ReHo values in the bilateral thalamus, right caudate nucleus and right precentral gyrus were higher, in children with CSNHL than HCs. However, there was no correlation between ReHo values and the CAP scores (p < 0.05). Using primary auditory cortex (PAC) as seed-based FC further analysis revealed enhanced FC in the visual cortex, proprioceptive cortex and motor cortex. And there were weak negative correlations between the FC values in the bilateral superior temporal gyrus, occipital lobe, left postcentral gyrus and right thalamus were weakly negatively correlated and the CAP score (p < 0.05). After auditory deprivation in preschool children with CSNHL, the local functions of auditory cortex, visual cortex, prefrontal cortex and somatic motor cortex are changed, and the prefrontal cortex plays a regulatory role in this process. There is functional reorganization or compensation between children's hearing and these areas, which may not be conducive to auditory language recovery after CI in deaf children.

Barriers to Meeting National Early Hearing Detection and Intervention Guidelines in a Diverse Patient Cohort.

To determine our audiology clinics status in meeting the Joint Committee on Infant Hearing recommended 1-3-6 benchmarks for identification and intervention for congenital sensorineural hearing loss and identify those factors contributing to delay in identification and intervention. This is a retrospective case series. Children with sensorineural hearing loss who underwent auditory brainstem response (ABR) testing, hearing aid evaluation, or cochlear implant mapping at our tertiary pediatric medical center between January 2018 and December 2021 were included. Simple and multiple linear regression analyses were used to identify social, demographic, and health factors associated with primary outcomes, defined as age at hearing loss identification, age at intervention (here defined as amplification start), and interval between identification and intervention. Of 132 patients included, mean age was 2.4 years, 48% were male, and 51% were Hispanic. There was significant association between each Hispanic ethnicity (p = 0.005, p = 0.04, respectively), insurance type (p = 0.02, p = 0.001, respectively), and later age at identification and intervention. In multivariable analyses, Hispanic ethnicity was significantly associated with both delays in identification and intervention (p = 0.03 and p = 0.03, respectively), and public insurance was associated with delays in intervention (p = 0.01). In addition, the total number of ABRs was significantly associated with both older age of identification and intervention (p < 0.001, p < 0.001, respectively). Mediator analysis demonstrated that the effect of ethnicity on age at identification is mediated by the total number of ABRs performed. A significant association between total number of ABRs and age at identification and intervention for children with hearing loss exists. Hispanic ethnicity was associated with delays in meeting milestones, further mediated by the number of ABRs, providing a potential avenue for intervention in addressing this disparity.

THE BENEFITS OF EARLY COCHLEAR IMPLANTATION FOR SPEECH DEVELOPMENT IN CHILDREN WITH USHER SYNDROME: LITERATURE REVIEW

IntroductionUsher syndrome (USH) is a rare autosomal recessive genetic disorder characterized by sensorineural hearing loss (SNHL), vision loss (retinitis pigmentosa), and occasional balance impairment. Depending on the severity and onset of hearing loss and coexisting vestibular dysfunction, USH is divided into three clinical types – USH1, USH2, USH3 – as well as atypical USH which combines features of all these three. The purpose of this review is to present the impact of cochlear implantation on speech development in children diagnosed with all types of Usher syndrome.Material and methodsAll relevant publications published in from 2013 to 2023 were retrieved from PubMed based on the keywords &lt;i&gt;Usher syndrome&lt;/i&gt;, &lt;i&gt;Usher syndrome diagnostics&lt;/i&gt;, &lt;i&gt;Usher syndrome hearing loss&lt;/i&gt;, &lt;i&gt;Usher syndrome cochlear&lt;/i&gt;, and &lt;i&gt;Usher syndrome speech&lt;/i&gt;. Exactly 67 papers were selected.ResultsBilateral cochlear implantation in children with Usher syndrome is beneficial for audiological and verbal development provided that hearing loss is detected early and implantation done promptly. In USH1 the preferred age is before 3 in the case of severe to profound congenital SNHL; in USH2 and USH3 the optimal time for implantation is hampered by the difficulty of estimating when hearing loss occurred and its rate of progression. After bilateral cochlear implantation, studies showed improvements in the categories of auditory performance (CAP), speech intelligibility rate (SIR), meaningful auditory integration scale (MAIS), meaningful use of speech scale (MUSS), and speech reception score (SRS), together with good development of speech perception and verbal communication.ConclusionsEarly diagnosis (before the onset of vision loss) and early bilateral cochlear implantation in children who have suffered severe to profound SNHL due to Usher syndrome reduces disability and maximizes auditory–oral communication skills, significantly increasing their quality of life.

Congenital Unilateral Hearing Loss from Cochlear Nerve Canal Stenosis

A 2-month-old baby girl presented with a failed neonatal otoacoustic emission (OAE) hearing screening in the left ear. Combined Auditory Brainstem Response/Auditory Steady-State Response (ABR/ASSR) testing confirmed the presence of a unilateral left moderate to severe hearing loss. No Joint Committee on Infant Hearing (JCIH) risk factors for early childhood hearing loss1 were identified. She subsequently underwent computed tomography (CT) of the temporal bones to determine the presence of any inner ear malformation. No abnormalities of the internal auditory canal, cochlea, semicircular canals and ossicles were noted by the radiologist, and the study was officially reported as a “normal temporal bone CT scan.” Independent review of the CT imaging revealed the presence of a visually apparent disparity in the width of the cochlear nerve canals. (Figure 1) Measurement of the cochlear nerve canal width in the axial plane parallel to the infraorbitomeatal line2 using the length measurement tool in the DICOM imaging software (RadiAnt DICOM Viewer, Version 2024.1, Medixant) indicated a cochlear nerve canal width of 2.18 mm on the right and 1.02 mm on the left. (Figure 2) Applying the suggested cutoff point of 1.2 mm as described by Lin et al.,2 we identified the presence of left cochlear nerve canal stenosis as the etiology of the congenital unilateral hearing loss. The cochlear nerve canal, which has also been referred to as the bony canal for the cochlear nerve (BCNC), cochlear aperture, and cochlear fosette, is the bony transition point between the internal auditory canal and the cochlear modiolus. A relationship between a hypoplastic cochlear nerve canal and congenital sensorineural hearing loss was first suggested by Fatterpekar et al. in 2000.3 Subsequent studies confirmed the association between cochlear nerve canal stenosis and sensorineural hearing loss that ranges from near-normal to profound, with a statistically significant relationship between the degree of hearing loss and the degree of stenosis.4 Various cutoff points to define stenosis of the cochlear nerve canal have been identified in the medical literature. These cutoff points range from 1.2 mm to 1.7 mm when the canal width is measured in the axial plane.2 This particular case demonstrated clear-cut evidence of cochlear nerve canal stenosis, as it satisfied the smallest cutoff criteria (&lt; 1.2 mm) seen in the medical literature. The identification of cochlear nerve canal stenosis as the cause of congenital sensorineural hearing loss is important not only from a diagnostic point, but also from a prognostic perspective. Cochlear nerve deficiency has been noted to be highly prevalent among pediatric patients with cochlear nerve canal stenosis,5 and this has significant negative implications in relation to rehabilitation with external hearing devices and cochlear implants.

Comparison of Depth of Mastoid Antrum on High Resolution Computed Tomography and Per Operatively in Cases Undergoing Mastoidectomy.

To compare the depth of mastoid antrum on High Resolution Computed Tomography and per operatively in cases undergoing mastoidectomy. This prospective observational study was done in a tertiary care Army Hospital with 35 patients meriting cortical mastoidectomy surgery. The patients underwent HRCT of temporal bone as a routine pre-operative work up, where depth of mastoid antrum was measured from dome of lateral semicircular canal to outer cortex of temporal bone. Depth was also recorded per-operatively with the help of measuring scale. Measurements were correlated and data was analysed statistically. There were 12 male patients and 23 females. 6 patients were < 3years of age and 29 above. Study included 29 cases of Chronic Otitis Media and 6 of Bilateral Congenital Sensorineural Hearing Loss. Mean depth of mastoid antrum was 1.625cm ± 0.228 on HRCT, and 1.651cm ± 0.245 per-operatively. Depths of mastoid antrum on HRCT and per operatively amongst paediatrics as well as adult cases were comparable, but were more than the standard depth of 1cm in 5 (82.3%) paediatrics cases and ˃1.5cm in 24 (82.9%) adult patients. In absence of Koerner's Septum, mean HRCT depth was 1.60cm ± SD 0.23 and per operatively was 1.63cm ± SD 0.21; whereas in its presence mean HRCT depth was 1.84cm ± SD 0.069 and per-operatively was 1.85cm ± SD 0.42. Significant difference in depth was noted between adults and children, and between the cases with or without Koerner's Septum. However, difference in depth was not significant when compared between different genders, laterality of disease or disease pathology.

Serial case report: Radiological images of congenital sensorineural hearing loss patients with and without hypoplasia of the vestibulocochlear nerve

Background: Congenital Sensorineural Hearing Loss (SNHL) is a hearing loss caused by damage to the inner ear (cochlea), vestibulocochlear cranial nerve (N.VIII), or the innervation pathway from the inner ear to the brain that is acquired from birth. If hearing loss occurs from birth or before the period of speech development is not detected. Thus, this case report compares two patients with congenital sensorineural hearing loss with and without vestibulocochlear nerve hypoplasia. Case Description: The first case was a 4-year-old girl with the main complaint of not hearing and responding to calls since the age of 1.5 years. Temporal CT scan and MRI results did not show existing organ and structural abnormalities, so suspected retro-cochlear auditory neuropathy. Patients undergo the installation of a cochlear implant in the left ear with good results. Case second, a 3-year-old girl with Down Syndrome who has not been able to speak since birth. CT scan results showed left and right basal cochlea 1.5 turns and bilateral jugular notch dehiscence, while MRI results showed vestibulocochlear nerve hypoplasia, narrowing of the IAC opening width 1.5 turns cochlea. If this happens, a cochlear implant cannot be done because abnormality finding is a contraindication operation. Conclusion: CT-scan and MRI examination are necessary to evaluate the structures and organs in the outer, middle and inner ear because the presence or absence of structural abnormalities found in the patient will significantly impact further management.

Early-stage use of hearing aids preserves auditory cortical structure in children with sensorineural hearing loss.

Hearing is critical to spoken language, cognitive, and social development. Little is known about how early auditory experiences impact the brain structure of children with bilateral sensorineural hearing loss. This study examined the influence of hearing aid use and residual hearing on the auditory cortex of children with severe to profound congenital sensorineural hearing loss. We evaluated cortical preservation in 103 young pediatric cochlear implant candidates (55 females and 48 males) by comparing their multivoxel pattern similarity of auditory cortical structure with that of 78 age-matched children with typical hearing. The results demonstrated that early-stage hearing aid use preserved the auditory cortex of children with bilateral congenital sensorineural hearing loss. Children with less residual hearing experienced a more pronounced advantage from hearing aid use. However, this beneficial effect gradually diminished after 17months of hearing aid use. These findings support timely fitting of hearing aids in conjunction with early implantation to take advantage of neural preservation to maximize auditory and spoken language development.

483 Radiographic Changes in the Auditory Pathway to Predict Outcomes of Children with Hearing Loss

OBJECTIVES/GOALS: Early diagnosis of congenital sensorineural hearing loss (SNHL) is of paramount importance in preventing speech and language impairment.Diffusion tensor imaging (DTI) MRI can identify brain microstructural changes that may potentially contribute towards prognosticating rehabilitation. METHODS/STUDY POPULATION: We retrospectively reviewed pediatric patients with SNHL who obtained DTI MRI between 2011 and 2019, identifying 16 pediatric patients (age &lt;18 years) with at least moderate asymmetric/bilateral SNHL., and gender-matched controlswithout neurological, developmental, or MRI-based brain macrostructural abnormalities. The following brainstem regions and tracts of the auditory pathway were assessed: superior olivary nucleus (SON), inferior colliculus (IC), ipsilateral tracts between the inferior colliculus and superior olivary nucleus (IC-SON). Diffusion values for bilateral regions and tracts were generated, then averaged to calculate a mean value for fractional anisotropy (FA) and mean diffusivity (MD) for each subject. RESULTS/ANTICIPATED RESULTS: Significant differences were identified in FA values of the SON between the SNHL cohort and controls (0.377±0.056 vs 0.422±0.052; p=0.009). No other FA or MD values were significantly different. In children £5 years, MD was significantly decreased in the SNHL cohort compared to controls in the IC (0.918±0.051 vs 1.120±0.142; p&lt;0.001). In children &gt;5 years, there were no significant differences in MD (1.124±0.198 vs 0.997±0.103; p = 0.119). There were no significant differences in MD or FA in the white matter fibers of the IC-SON tract [applewebdata%3A//720AAF0C-C4CF-459C-A42A-6BAA56C4E4CA#_msocom_2]. DISCUSSION/SIGNIFICANCE: This is the first study to assess microstructural changes in brainstem auditory pathway regions among children with SNHL. Longitudinal studies are warranted to assess the predictive value of DTI imaging for long-term outcomes and prognosticating intervention.

Cochlear Implantation in Children with Single-Sided Deafness: Preoperative Assessment and Device Use

Objectives: To characterize the first cohort of cochlear implanted pediatric patients with single-sided deafness (SSD) at Aarhus University Hospital, Denmark. Data includes etiology, age at implantation, balance testing, and language assessment prior to implantation as well as data log of Cochlear Implant usage. Methods: Clinical data from 34 children with SSD (21 females (62%) and 13 males (38%)), implanted with Cochlear Implant (CI) during 2018-2023, was analyzed. Results: Acquired prenatal and postnatal sensory disorders toxoplasmosis, rubella, cytomegalovirus and herpes simplex (TORCH) risk factors were associated with sensorineural hearing loss (SNHL) in 19 cases (56%). Congenital Cytomegalovirus (cCMV) DNA was diagnosed in 17 samples (50%). The cause of the SNHL remained unknown for 11 (32.4%) children. In 6 (66.7%) of the cases with unknown etiology, CT scan showed inner ear malformations (IEM). The mean (SD) age for implantation was 4.2 ± 3.5 years. For the children with congenital SNHL, the mean (SD) age for implantation was 2.6 ± 1.6 years. For the children with acquired SNHL, the mean (SD) age for implantation was 6.9 ± 4.3 years. Data log showed that children with SSD and CI wore their processor 6.2 ± 3.73 (1 SD) h/day. Conclusions: Further work is needed in order to assess how etiology, age at implantation, and device use affect outcome. Understanding of the long-term outcomes associated with CI in children with SSD can contribute to more thorough counselling on outcome expectations and the best auditory rehabilitation.

Cochlear Implantation in Inner Ear Malformations

Introduction: Cochlear Implantation (CI) has proven to be an effective treatment for severe bilateral Sensorineural Hearing Loss (SNHL). Inner ear malformation is a rare anomaly and occurs in approximately 20% of cases with congenital SNHL. There are particular challenges in the implantation of malformed cochleae, such as in cases of facial nerve anomalies, Cerebrospinal Fluid (CSF) leaks or facial stimulation, and the outcomes may differ depending on the severity of the malformation. The aim of this study was to assess the impact of Inner Ear Malformations (IEMs) on surgical complications and outcomes of cochlear implantation. Methods: Between 2018 and 2022, 9 patients with inner ear malformations were implanted in our department and completed at least 1 year of follow-up. The age range was between 2 years and 4 months and 5 years (average, 3.36 yr). Auditory performance, receptive and expressive language skills, and production and use of speech were evaluated preoperatively and at least 1 year after implantation. Results: In the study group, the most common malformation was an isolated Enlarged Vestibular Aqueduct (EVA) (55,5%). Overall, the patients with IEMs showed significant improvement in auditory-verbal skills. In general, the patients who had normal cochleae scored significantly better compared to patients with IEMs. Conclusion: Based on these findings, cochlear implantation is surgically feasible in patients with common cavity, IP types I and II, and EVA. The surgeon should be ready to make modifications in the surgical approach because of the abnormal course of the facial nerve and be ready to produce special precautions to cerebrospinal fluid gusher. Patients with EVA were the best performers in terms of auditory-verbal skills.