Cochlear Nerve Deficiency Research Articles

The Effect of Interphase Gap on Neural Response of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency and Children With Normal-Sized Cochlear Nerves.

This study aimed to compare the effects of increasing the interphase gap (IPG) on the neural response of the electrically stimulated cochlear nerve (CN) between children with CN deficiency (CND) and children with normal-sized CNs. Study participants included 30 children with CND and 30 children with normal-sized CNs. All subjects were implanted with a Cochlear Nucleus device with the internal electrode array 24RE[CA] in the test ear. The stimulus was a charge-balanced, cathodic leading, biphasic pulse with a pulse-phase duration of 50 μsec. For each subject, the electrically evoked compound action potential (eCAP) input/output (I/O) function was measured for 6 IPGs (i.e., 7, 14, 21, 28, 35, and 42 μsec) at 3 electrode locations across the electrode array. For each subject and each testing electrode, the highest stimulation used to measure the eCAP I/O function was the maximum comfortable level measured with an IPG of 42 μsec. Dependent variables (DVs) were the maximum eCAP amplitude, the eCAP threshold, and the slope of the eCAP I/O function estimated using both linear and sigmoidal regression functions. For each DV, the size of the IPG effect was defined as the proportional change relative to the result measured for the 7 μsec IPG at the basal electrode location. Generalized linear mixed effect models with subject group, electrode location, and IPG duration as the fixed effects and subject as the random effect were used to compare these DVs and the size of the IPG effect on these DVs. Children with CND showed smaller maximum eCAP amplitudes, higher eCAP thresholds, and smaller slopes of eCAP I/O function estimated using either linear or sigmoidal regression function than children with normal-sized CNs. Increasing the IPG duration resulted in larger maximum eCAP amplitudes, lower eCAP thresholds and larger slopes of eCAP I/O function estimated using sigmoidal regression function at all three electrode locations in both study groups. Compared with children with normal-sized CNs, children with CND showed larger IPG effects on both the maximum eCAP amplitude and the slope of the eCAP I/O function estimated using either linear or sigmoidal regression function, and a smaller IPG effect on the eCAP threshold than those measured in children with normal-sized CNs. Increasing the IPG increases responsiveness of the electrically stimulated CN in both children with CND and children with normal-sized CNs. The maximum eCAP amplitude and the slope of the eCAP I/O function measured in human listeners with poorer CN survival are more sensitive to changes in the IPG. In contrast, the eCAP threshold in listeners with poorer CN survival is less sensitive to increases in the IPG. Further studies are warranted to identify the best parameters of eCAP results for predicting CN survival before this eCAP testing paradigm can be used as a clinical tool for evaluating neural health for individual cochlear implant patients.

Inner-ear malformations as a cause of single-sided deafness.

To determine the prevalence and distribution of inner-ear malformations in congenital single-sided deafness cases, as details of malformation type are crucial for disease prognosis and management. A retrospective study was conducted of 90 patients aged under 16 years with congenital single-sided deafness. Radiological findings were evaluated using computed tomography and magnetic resonance imaging. Inner-ear malformations were identified and cochlear nerve status was determined in affected ears. Out of 90 ears, 42 (46.7 per cent) were found to have inner-ear malformation. Isolated cochlear aperture stenosis was the most common anomaly (n = 18, 20 per cent), followed by isolated cochlear aperture atresia (n = 11, 12.2 per cent) and cochlear hypoplasia (n = 7, 7.8 per cent). Cochlear nerve deficiency was encountered in 41 ears (45.6 per cent). The internal auditory canal was also stenotic in 49 ears (54.4 per cent). Inner-ear malformations, especially cochlear aperture anomalies, are involved in the aetiology of single-sided deafness more than expected. The cause of single-sided deafness differs greatly between congenital and adult-onset cases. All children with single-sided deafness should undergo radiological evaluation, as the prognosis and management, as well as the aetiology, may be significantly influenced by inner-ear malformation type.

Therapeutic challenges and clinical characteristics of single-sided deafness in children

IntroductionThe clinical implications of single-sided deafness (SSD) in children has historically been underappreciated by patients and providers alike, despite a large body of literature on the wide-ranging neurocognitive, language, scholastic, and functional impairments that occur. Conventional amplification options are marked by variable results and frequent loss of follow-up. MethodsRetrospective case series for pediatric SSD from 2008 to 2018. Results88 children with congenital SSD were identified. Seventeen (N = 17/88, 23.9%) passed their newborn hearing screen. Median age at first otolaryngology evaluation was 0.65 years (range 0.1–16.9 years). Most common etiologies included cochlear nerve deficiency (N = 39, CND, 44.3%), unknown (N = 30, 35.2%), inner ear malformation (N = 7, 8.0%), and congenital cytomegalovirus (N = 6, 6.8%). 32.5% of patients elected for continued observation only, followed by bone conduction hearing aid (27.7%), contralateral routing of sound aid (20.5%), conventional hearing aid (13.3%), or cochlear implant (6%). Lack of follow-up at ≥1 year was common (39.8%). Of those with device use data (N = 39), 84.7% reported either discontinued or <6 h of daily use. ConclusionsDespite early diagnosis and evaluation, the pediatric SSD cohort is characterized by high rates of loss of follow-up and amplification discontinuation. Cochlear nerve deficiency is commonly seen in congenital SSD. Early specialist referral is critical for habilitation evaluation. Patients and caregivers should be educated on the significant implications of unilateral hearing loss.

Single-sided deafness after sudden hearıng loss: late effect on cochlear nerve size.

Single-sided deafness (SSD) is a condition where an individual has non-functional hearing in one ear and receives no clinical benefit from amplification in that ear, with the contralateral ear possessing normal audiometric function. Cochlear implant presents a good choice in rehabilitation of SSD. The presence of a deficient cochlear nerve (CN) has been linked to poor performance with cochlear implants. CN can be measured by imaging techniques. The objective of this study was to compare CN diameter in patients who had a history of single-sided deafness because of sudden hearing loss. Retrospective study where radiologist was blind designed. 53 SSD patients who had a history of sudden hearing loss and MRI at least 5years after the sudden hearing loss were included in this retrospective study. High-resolution 3-D constructive interference in steady state (CISS)-sequence magnetic resonance (MRI) images was review by the neurotology-experienced blind radiologist. Vertical, horizontal and area measurements of cochlear nerve between the deaf and the normal ear were made. There was no statistically significant difference between the normal ear and deaf ear of the subjects in terms of cochlear nerve vertical diameter, horizontal diameter and area. (respectively, p = 0.250; p = 0.183; p = 0.874) CONCLUSION: The numbers of remaining cochlear neurons and spiral ganglion cells in the implanted deaf ears are critical and evidence was not found for spiral ganglion cell loss in the sudden hearing loss deaf ear with SSD in MRI. In the light of all these findings, implantation would be a good choice for rehabilitation in postlingual SSD regardless of auditory deprivation duration.

Bimodal stimulation in children with inner ear malformation: One side cochlear implant and contralateral auditory brainstem implant.

To determine audiological outcomes of children who use a cochlear implant (CI) in one ear and an auditory brainstem implant (ABI) in the contralateral ear. Retrospective case review. Tertiary referral hospital. Twelve children followed with CI and contralateral auditory brainstem implant (ABI) by Hacettepe University Department of Otorhinolaryngology and Audiology in Turkey. All children were diagnosed with different inner ear malformations with cochlear nerve aplasia/hypoplasia. CI was planned in the ear with better sound detection during behavioural testing with inserted ear phones and with better CN as seen on MRI. Due to the limited auditory and speech progress with the cochlear implant, ABI was performed on the contralateral ear in all subjects. Audiological performance and auditory perception skills of children with cochlear nerve deficiency (CND) who use bimodal electrical stimulation with CI and contralateral ABI. Mean age of the subjects was 84.00±33.94months. Age at CI surgery and ABI surgery was 25.00±10.98months and 41.50±16.14months, respectively. However, hearing thresholds only with CI and only with ABI did not reveal significant difference, and auditory perception scores improved with bimodal stimulation. The MAIS scores were significantly improved from unilateral CI to bimodal stimulation (P=.002). Pattern perception and word recognition scores were significantly higher with the bimodal condition when compared to CI only and ABI only conditions. Children with CND showed better performance with CI and contralateral ABI combined. Depending on the audiological and radiological results, bimodal stimulation should be advised for children with CND.

Recommendations for Measuring the Electrically Evoked Compound Action Potential in Children With Cochlear Nerve Deficiency.

This study reports a method for measuring the electrically evoked compound action potential (eCAP) in children with cochlear nerve deficiency (CND). This method was developed based on experience with 50 children with CND who were Cochlear Nucleus cochlear implant users. This method includes three recommended steps conducted with recommended stimulating and recording parameters: initial screen, pulse phase duration optimization, and eCAP threshold determination (i.e., identifying the lowest stimulation level that can evoke an eCAP). Compared with the manufacturer-default parameters, the recommended parameters used in this method yielded a higher success rate for measuring the eCAP in children with CND. The eCAP can be measured successfully in children with CND using recommended parameters. This specific method is suitable for measuring the eCAP in children with CND in clinical settings. However, it is not suitable for intraoperative eCAP recordings due to the extensive testing time required.

Long-Term Outcomes of Cochlear Implantation in Children with Cochlear Nerve Deficiency

Objective: To evaluate long-term auditory outcomes with the continuous use of cochlear implants (CIs) in pediatric patients with cochlear nerve deficiencies (CNDs). Methods: Six children with CNDs who received CIs (mean age: 38.7 months old) were retrospectively evaluated. Audiological performance was assessed with a mean follow-up of 126 months (range 63-161) using unaided and aided pure-tone average (PTA) thresholds, categories of auditory performance-II (CAP-II) scores, and the perception of Japanese monosyllabic words. CI use was evaluated by retrospective chart review. Results: Two of the six patients did not achieve sufficient PTA threshold improvement and discontinued CI use more than 7 years after implantation. The remaining four patients demonstrated improvements in PTA thresholds with CIs, while their speech understanding remained poor with CAP-II scores of 5, even in the best cases. They did not develop open-set speech perception, resulting in continued sign language use. Conclusion: The long-term auditory outcomes of CI use in CND patients are poor, and some patients may discontinue CI use. Continuous support and education in using sign language is highly recommended for children with CNDs undergoing cochlear implantation.

Preoperative dual imaging evaluation of profound sensorineural hearing loss in patients for cochlear implantation

Background: Profound sensorineural hearing loss (SNHL) may be the result of major inner ear structural malformations, and cochlear implantation remains the only viable treatment option. High-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) are indispensable for optimum preoperative implant workup and thus play a vital role in patient selection, pre-implantation counseling, and surgical management. Aim and Objectives: The aim of this study is to evaluate patients with profound SNHL for cochlear implantation preoperatively on both HRCT and MRI and to compare imaging findings in both modalities. Materials and Methods: This longitudinal prospective study was conducted in the Department of Radiology of a tertiary care-based hospital in North India. A total of 45 patients (90 temporal bones) with clinically diagnosed bilateral profound SNHL were included in the study. Patients with a previous history of temporal bone injury were excluded from the study. All cases were evaluated on both 128 slice Philips computed tomography (CT) machine and 1.5 Tesla Siemens Magnetom MRI scanner. Each temporal bone was systematically analyzed for anatomical and structural abnormalities. Results: Both high-resolution CT and MRI played vital roles in the workup of patients with profound SNHL for cochlear implantation and allowed accurate assessment of critical inner ear abnormalities. Cochlear malformations (30%) were responsible for the majority of structural abnormalities in this study with Type II incomplete partition (8.9%) being the most common. Cochlear nerve deficiency was seen in 20 cases (22.2%) and was diagnosed only on MRI. Similarly, early fibrosis and abnormal signal intensity were also detected only on MRI, which were missed on CT. Conclusions: Both high-resolution CT and high magnet MRI complement each other and reduce the chances of missing critical findings, which are crucial for surgical management and planning. Thus, it is advisable to perform dual imaging with both modalities wherever and whenever possible, to offer maximum information to treating surgeon preoperatively.

Value of Routine Magnetic Resonance Imaging for the Preoperative Assessment of Cochlear Implant Candidates.

BackgroundThe selection of an appropriate imaging technique for assessment before cochlear implantation is critical for precise diagnosis and management. While magnetic resonance imaging (MRI) is used for the diagnosis of several conditions, such as labyrinthitis ossificans, cochlear nerve deficiency, and neoplasms, high-resolution computed tomography (HRCT) provides excellent details of the temporal bone. However, it remains unclear whether routine MRI provides any additional benefits over HRCT.ObjectivesTo assess the added value of MRI as a screening tool for temporal bone abnormalities in cochlear implant candidates through comparisons of its findings with those of HRCT.Materials and methodIt is a retrospective analysis of preoperative HRCT and MR images in a tertiary referral center. A total of 308 patients who underwent MRI and HRCT examinations before cochlear implantation between 2013 and 2015 were included. Preoperative HRCT and MR images were screened for temporal bone abnormalities by a senior neurotologist and a neuroradiologist.ResultsHRCT detected inner ear deformities in 51 of the 308 (16.6%) subjects, whereas MRI revealed abnormalities in only 18 (5.8%) of subjects. HRCT detected the same inner abnormalities in 16 of the 18 (88.9%) subjects diagnosed by MRI, whereas it showed normal results for the remaining two subjects. MRI detected cochlear nerve aplasia/hypoplasia in 13 subjects, 11 of whom had associated inner ear deformities that were detected by HRCT. The MR images of nine subjects showed cochlear fibrosis, which was confirmed by HRCT in all nine subjects.ConclusionIn this study, MRI did not exhibit significant additional benefits over HRCT, and its routine use for the preoperative assessment of CI candidates was not justified. However, MRI is warranted for subjects at an increased risk of cochlear nerve aplasia due to an inner ear deformity or a narrow internal auditory canal. The establishment of criteria that facilitate the performance of MRI only when absolutely needed will reduce healthcare costs, prevent unnecessary exposure to the risks associated with general anesthesia, and shorten delays before cochlear implantation.

Electrically evoked ABR during cochlear implantation and postoperative development of speech and hearing abilities in infants with common cavity deformity as a type of inner ear malformation

Background: The electrically evoked auditory brainstem response (eABR) during cochlear implantation in common cavity (CC) deformity has not been clinically well studied.Aim/Objective: To investigate the eABR wave configuration during cochlear implantation, the postoperative development of hearing, and educational settings in infants with CC deformity.Materials and Methods: Nine infants who were congenitally deaf and found to have CC deformity and suspected cochlear nerve deficiency by temporal bone CT and MRI were studied. All of them underwent sequential and unilateral cochlear implantation and their eABRs were recorded during the surgery. The postoperative development was followed up.Results: eABRs of all the nine infants with CC deformity showed that the mean peak of the evoked wave V (eV) was the same as that in controls at latencies but was twofold higher than that in controls at thresholds and their postoperative hearing thresholds improved markedly.Conclusion and Significance: The brainstem auditory pathways of the infants were considered intact on the basis of the eV peak latencies in the eABRs. The postoperative development of their speech and hearing abilities and their educational settings varied, probably because of the twofold higher thresholds of their eABRs and limited number of auditory neural units.

Preoperative imaging and electrophysiological evaluation of cochlear implantation in children with cochlear nerve dysplasia

Objective:The aim of this study is to investigate the use of CT, magnetic resonance imaging （MRI）, functional magnetic resonance （fMRI） and electrical evoked auditory brainstem response in children with cochlear nerve deficiency （CND） before cochlear implantation （CI） （electrically evoked auditory brain stem response, EABR） evaluated auditory pathway, auditory cortex function, and cochlear nerve function. Method:Of 6 children with bilateral profound sensorineural hearing loss, bilateral internal auditory meatus stenosis was diagnosed by CT as in 4 cases and unilateral internal auditory meatus stenosis in 1 case. In 3 cases, oblique sagittal MRI reconstruction of the internal auditory meatus showed only facial nerve and vestibular nerve existence. 6 cases were diagnosed as CND by imaging, among which underwent fMRI and EABR in 3 cases, respectively. All the children received unilateral CI and were followed up for at least 1 year after hearing and speech rehabilitation. Result:fMRI was examed in 3 cases with CND. It showed that the right auditory cortex was activated in 1 case after sound given to the left ear but no activation was found in the left cortex when sound given to the right ear. 1 case showed activation in bilateral transverse temporal gyrus while sound was given to the left, right and both ears at 2000Hz. Another case had no activation in both auditory cortex. EABR detection elicited V wave in 2 of 3 cases. 6 children received audiological and speech evaluation 1 month, 6 and 12 months after CI. Among them, the hearing level was improved within 6 months after surgery in 4 cases, and the threshold of sound field was （48.15±6.60） dB HL, MAIS and CAP scores were improved. However, SIR score improvement is limited in 3 cases. The hearing level was improved in 1 case, but speech rehabilitation was poor mainly due to the older age. Conclusion:Preoperative comprehensive application of imaging and electrophysiological evaluation of children with CND can more accurately assess the integrity of the auditory pathway and understand the function of the cochlear nerve. It has important reference significance for whether or not to perform surgery. There was a significant difference in auditory speech rehabilitation after CND in children with CND.

Cochlear Nerve Hypoplasia: Audiological Characteristics in Children and Adults

Background: Cochlear nerve deficiency is a general term used to describe both cochlear nerve hypoplasia (CNH) and cochlear nerve aplasia. Although these two conditions can have similar results on audiological evaluation, CNH yields more variation in audiological tests. Objectives: To describe the audiological characteristics of the CNH cases in our series in relation to radiological findings. Methods: We reviewed the medical charts, audiological findings, and radiological findings on cases with CNH. We included cases with CNH in one ear or both ears. Out of 90 subjects with CNH, we included a total of 40 individuals (21 women and 19 men; 49 ears) in the current study. We reviewed and analyzed the participants’ audiological test results according to the radiological findings. Results: Cases with CNH showed variations according to the cochlear structure. There were 13 normal cochleae, 4 with incomplete partition type I, and 32 with cochlear hypoplasia. The accompanying cochlear apertures also showed variation: 17 were normal, 28 stenotic, and 4 aplastic cochlear apertures. The subjects displayed hearing loss ranging from moderate to profound; furthermore, 4 subjects had no response to sound whatsoever. The degree of hearing loss was not statistically significantly different with regard to the presence or absence of cochlear malformation with CNH (p > 0.005). We observed both sensorineural hearing loss and mixed-type hearing loss among the CNH cases. Conclusions: CNH is the presence of a cochlear nerve that is smaller in diameter than the facial nerve. It can be accompanied with other associated inner ear malformations of different degrees of severity. We observed degrees of hearing loss ranging from moderate to profound.

Systematic review of cochlear implantation in CHARGE syndrome

Objective: CHARGE syndrome presents with a collection of congenital anomalies affecting multiple organs. Ear and temporal bone anomalies, including hearing loss are highly prevalent.We present an aid to management of this challenging condition and report the strategies and outcomes of cochlear implantation.Methods: Systematic review of Medline, EMBASE, Web of Science, CENTRAL and clinicaltrials.gov was performed up to 21/10/2018The review and meta-analysis of studies were performed according to the PRISMA statement.Patient demographics, comorbidity, anatomical factors, details of cochlear implantation and audiological outcome were extracted and summarized. Anatomical and surgical factors were evaluated by meta-analysis. Audiological outcomes reported were too heterogeneous for meta-analysis.All statistics were calculated with SPSS v23.0 (IBM, New York, USA).Results: Thirty-one studies reported 165 cochlear implants in 156 patients with CHARGE syndrome. Temporal bone and facial nerve anomalies were common.Discussion: The assessment and management of patients with CHARGE syndrome undergoing cochlear implantation is challenging. Outcomes may be affected by cochlear nerve deficiency, inner ear anomalies, and developmental delay. Surgery is almost invariably complicated by abnormal anatomy, and increased incidence of complications.Conclusion: A careful, case-by-case assessment of an individual's requirements within a multi-disciplinary setup is essential for achieving the best possible outcome.

TEMPORAL BONE IMAGING IN UNILATERAL SEVERE TO PROFOUND SNHL.

Background: The effect of unilateral sensor ineural hearing loss (UHL) on the quality of life is well documented. Studies found a direct link between UHL and educational and social delays. Radiological studies aimed to detect the associated anomalies of the earen countered a wide variation in the rates of incidence. Aim of the work: Our study aims to detect and give an estimate about the rate of incidence of different anomalies. Patients and methods: A review of the medical records of Audiology department in Eldemerdash hospital between 2014 to 2017 was done. Only cases with severe to profound USNHL diagnosed before age of 12 years were included. Clinical examination, full audiological assessment, MRI and CT temporal bone were done for all cases and results were reviewed for each patient. Results: 50 cases were included (8 cases with severe USNHL and 42 cases with profound USNHL). The mean age of diagnosis was 7.6 years.Only16 cases (32%) had risk factors known to contribute to SNHL. The most common abnormality found was cochlear nerve (CN)deficiency in 22 cases (44%).Bilateral findings were present in 4 cases (8%). Conclusion: Radiological evaluation is not only for detection of the cause but also allows proper counselling and exploring the possible options of rehabilitation.

Imaging findings in pediatric single-sided deafness and asymmetric hearing loss.

To examine the imaging findings on computer tomography (CT) and magnetic resonance imaging (MRI) in pediatric single-sided deafness (SSD) and asymmetric hearing loss (ASH). The medical records of 189 pediatric patients with SSD and ASH were retrospectively reviewed, and imaging findings were compared. SSD was defined as unilateral profound hearing loss and contralateral normal hearing ear. In the ASH group, ASHw was defined as the worse hearing ear with profound hearing loss, while ASHb was defined as the better hearing ear with mild-moderate hearing loss. There were 170 patients with SSD and 19 patients with ASH. In the SSD group, 83 patients (48.8%) had imaging findings associated with hearing loss. In the ASH group, such imaging findings were found in six (31.6%) of the ASHw and in five (26.3%) of the ASHb ears. The most common finding in the SSD group was cochlear nerve deficiency (50.6%), followed by cochlear dysplasia (39.8%) and enlarged vestibular aqueduct (26.5%). In the ASH groups, cochlear dysplasia was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears, and enlarged vestibular aqueduct was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears. Imaging studies identified the etiology in half of the cases of SSD and in one-third of ASH patients. Our findings strongly support the use of imaging studies in the evaluation of pediatric SSD and ASH. 4 Laryngoscope, 130:1007-1010, 2020.

Assessment of the Clinical Benefit of Imaging in Children With Unilateral Sensorineural Hearing Loss

Imaging used to determine the cause of unilateral sensorineural hearing loss (USNHL) in children is often justified by the high likelihood of detecting abnormalities, which implies that these abnormalities are associated with hearing loss and that imaging has a positive contribution to patient outcome or well-being by providing information on the prognosis, hereditary factors, or cause of hearing loss. To evaluate the diagnostic yield of computed tomography (CT) and magnetic resonance imaging (MRI) in children with isolated unexplained USNHL and investigate the clinical relevance of these findings. Cochrane Library, Embase, PubMed, and Web of Science databases were searched for articles published from 1978 to 2017 on studies of children with USNHL who underwent CT and/or MRI of the temporal bone. Two authors (F.G.R. and E.N.B.P.) independently extracted information on population characteristics, imaging modality, and the prevalence of abnormalities and assessed the studies for risk of bias. Eligibility criteria included studies with 20 or more patients with USNHL who had CT and/or MRI scans, a population younger than 18 years, and those published in English. The pooled prevalence with 95% CI of inner ear abnormalities grouped according to finding and imaging modality. Of 1562 studies, 18 were included with a total of 1504 participants included in the analysis. Fifteen studies were consecutive case studies and 3 were retrospective cohort studies. The pooled diagnostic yield for pathophysiologic relevant findings in patients with unexplained USNHL was 37% for CT (95% CI, 25%-48%) and 35% for MRI (95% CI, 22%-49%). Cochleovestibular abnormalities were found with a pooled frequency of 19% for CT (95% CI, 14%-25%) and 16% for MRI (95% CI, 7%-25%). Cochlear nerve deficiency and associated cochlear aperture stenosis had a pooled frequency of 16% for MRI (95% CI, 3%-29%) and 44% for CT (95% CI, 36%-53%), respectively. Enlarged vestibular aqueduct (EVA) was detected with a pooled frequency of 7% for CT and 12% for MRI in children with USNHL. Imaging provided insight into the cause of hearing loss in a pooled frequency of about 35% to 37% in children with isolated unexplained USNHL. However, none of these findings had therapeutic consequences, and imaging provided information on prognosis and hereditary factors only in a small proportion of children, namely those with EVA. Thus, there is currently no convincing evidence supporting a strong recommendation for imaging in children who present with USNHL. The advantages of imaging should be carefully balanced against the drawbacks during shared decision making.

Hearing Loss in Pediatric Septo-Optic Dysplasia.

To identify and characterize hearing loss (HL) in children with septo-optic dysplasia (SOD). Otologic and audiometric data for patients less than 18 years of age identified as having SOD who were seen in the Children's Healthcare of Atlanta-Scottish Rite Hospital clinic between 2013 and 2017 were collected and reviewed through a HIPAA-compliant medical record search. Relevant literature was also reviewed with the assistance of Medline. Sixty-four patients with SOD were identified, and 7 of those patients (10.9%) were diagnosed with hearing loss. Type of hearing loss was sensorineural (SNHL) in 5 patients (63%), mixed (MHL) in 1(14%), and conductive (CHL) in 1(14%). Bilateral loss presented in 60% (3/5) of SNHL patients, while the rest demonstrated unilateral loss. Unilateral findings included cochlear nerve deficiency (1) and atresia/microtia (1). Tympanostomy tubes were required in 57% (4/7) of SOD children with hearing loss. Amplification was successfully implemented in 86% (6/7). Hearing loss was found in nearly 11% of SOD children, and SNHL was identified as (63%) the predominant form of loss. To our knowledge, this is the first retrospective review of hearing loss in a pediatric SOD cohort and the first to report of cochlear nerve deficiency and atresia/microtia in this population. Based on these findings, early identification of hearing loss with imaging when appropriate and treatment of otitis in this population is recommended.

A Predictive Model for Cochlear Implant Outcome in Children with Cochlear Nerve Deficiency

The outcome of cochlear implantation (CI) in patients with cochlear nerve deficiency (CND) is variable, resulting in a wide range of speech perception performance, from degrees of environmental sound perception to conversation without lip-reading. Twenty-five cochlear implantees with CND were enrolled retrospectively to determine the factors correlated with CI outcome in patients with CND and to develop a predictive model for CI outcome. CI outcome was evaluated using the Categories of Auditory Performance (CAP) score at 2 years after CI. Patients with negative auditory brainstem response (ABR) showed a significantly lower CAP score than those with positive ABR (2.5 ± 1.7, 4.8 ± 0.7; p = 0.001). The area ratio of vestibulocochlear nerve (VCN) to facial nerve (FN) at the cerebellopontine angle on magnetic resonance images was positively correlated with CI outcome (p < 0.001). With multiple regression analysis, a predictive equation accounting for 66% of variance of CAP score at 2 years after CI was {bf{deduced}}:{bf{CAP}},{bf{score}}{boldsymbol{=}}{bf{0.7}}{boldsymbol{+}}{bf{1.9}}{boldsymbol{ast }}{boldsymbol{(}}{bf{ABR}}{boldsymbol{)}}{boldsymbol{+}}{bf{1.2}}{boldsymbol{ast }}(frac{{boldsymbol{V}}{boldsymbol{C}}{boldsymbol{N}}}{{boldsymbol{F}}{boldsymbol{N}}}). We found that preoperative ABR and area ratio of VCN to FN at the cerebellopontine angle could predict CI outcome in patients with CND. Preoperative counselling based on our predictive model might be helpful to determine treatment modality for auditory rehabilitation and which ear to implant.

Appropriate Imaging Modality for the Etiologic Diagnosis of Congenital Single-Sided Deafness in Children.

We aimed to compare the diagnostic yield between temporal bone computed tomography (TBCT) and internal auditory canal MRI (IAC MRI) for the etiologic diagnosis of children with congenital single-sided deafness (SSD) and the evaluation of cochlear implant (CI) candidacy. In the original cohort, 24 subjects with congenital SSD were enrolled and underwent both TBCT and IAC MRI. We recruited an additional 22 consecutive infants with congenital SSD (the supplementary cohort) and evaluated in particular the cochlear nerve (CN) integrity using IAC MRI. Cochlear nerve deficiency (CND) was classified as ‘absent’, ‘small’, and ‘indeterminate’ via mutual comparison between optical and parameters based on the MRI results. The most common etiologies were CND in the original cohort (19 out of 24). Notably, accurate evaluations of CN status (‘small CN’ = 2, ‘indeterminate CN’ = 2), inner ear malformations, and brain abnormalities were possible only with MRI. The ‘indeterminate CN’ tended to be more frequently detected in SSD ears than in unaffected ears. MRI appeared to be more accurate than TBCT in a meticulous differentiation of CN, which is crucial for the selection of appropriate CI candidacy among congenital SSD children. Additionally, we introduced the novel concept of ‘indeterminate CN’, of which the causal relationship with SSD awaits confirmation.

Prevalence and etiology of sensorineural hearing loss in children with down syndrome: A cross-sectional study

BackgroundThe prevalence and causes of sensorineural hearing loss (SNHL) in children with Down syndrome (DS) are poorly delineated. ObjectiveTo describe the prevalence, severity, laterality and underlying etiology of SNHL in a cohort of children with DS. MethodsA cross-sectional study was performed among all children with DS followed at the multidisciplinary Downteam of the Antwerp University Hospital. Patients' characteristics, risk factors for hearing loss, audiometric data and results of an etiological work-up were collected. ResultsAmong 291 patients in follow-up, 138 patients (47.4%) presented with hearing loss. In the majority this was caused by middle ear effusion and only 13 patients (4.5%) had sensorineural hearing loss, 7 boys and 6 girls with a mean age of 14.4 ± 7.4 years. Hearing loss was bilateral in 8 cases. Hearing loss severity was graded as mild in 38.5%, moderate in 30.8% and profound in 30.8% of the patients. An etiological work-up was completed in 9 children. Four patients presented with single sided deafness due to cochlear nerve deficiency. One patient had a genetic cause and in 2 patients the hearing loss was attributed to excessive noise exposure. The etiology of hearing loss was unknown in 6 patients. ConclusionSensorineural hearing loss is uncommon in children with DS with a prevalence of 4.5%. Etiological work-up may allow identifying a specific underlying cause. Cochlear nerve deficiency was found in 4 children with DS and single sided deafness.