Unilateral cochlear nerve deficiency in children

Evaluation of Cochlear Implantation in Children With Cochlear Nerve Absence or Deficiency

OBJECTIVE

To identify associations between cochleovestibular anatomy findings and hearing outcomes found in children with imaging evidence of an absent or hypoplastic cochlear nerve treated with cochlear implantation (CI).

STUDY DESIGN

retrospective review.

SETTING

Cochlear implant program at tertiary care center.

METHODS

A retrospective review was performed to identify children with imaging evidence of cochlear nerve absence or deficiency who underwent CI evaluation. High-resolution 3-dimensional T2-weighted magnetic resonance imaging in the oblique sagittal and axial planes were reviewed by a neuroradiologist to identify cochleovestibular anatomy. Hearing was assessed pre and postoperatively with Speech Perception Category scores.

RESULTS

Seven CI recipients were identified (n = 10 ears) who had bilateral severe to profound sensorineural hearing loss with lack of auditory development with binaural hearing aid trial and imaging evidence of cochlear nerve aplasia/hypoplasia. All ears had 2 nerves in the cerebellopontine angle (100%, n = 10), half of the ears had evidence of 2 or less nerves in the internal auditory canal (IAC). All children showed large improvement in speech perception after CI.

CONCLUSION

Our experience with CIs for children with absent or hypoplastic cochlear nerves demonstrates that CI can be a viable option in select patients who satisfy preoperative audiological criteria. Radiological identification of a hypoplastic or aplastic cochlear nerve does not preclude auditory innervation of the cochlea. CI recipients in this subgroup must be counseled on difficulty in predicting postimplantation language and speech outcomes, and cautioned about facial nerve stimulation.

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.

High Prevalence of Cochlear Nerve Deficiency in Pediatric Patients With Cochlear Aperture Stenosis

OBJECTIVE

Cochlear nerve deficiency (CND) is a common radiologic finding among unilateral sensorineural hearing loss (USNHL) patients. It is generally detected with magnetic resonance imaging (MRI), which is associated with higher cost, less availability, and possible need for sedation. Therefore, identifying computed tomography (CT) findings, such as cochlear aperture stenosis (CAS), that can reliably predict CND is valuable. Our study aimed to determine the prevalence of CND in pediatric patients with CT-diagnosed CAS.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary care center.

METHODS

We included pediatric patients diagnosed with CAS on temporal bone CT and with available temporal bone MRI. For each patient, an otolaryngologist and a pediatric neuroradiologist measured the cochlear aperture width on CT to confirm CAS (cochlear aperture < 1.4 mm) and assessed the status of the cochlear nerve on MRI.

RESULTS

Fifty-five patients, representing 65 ears, had CAS on CT measurement. Median cochlear aperture width in CAS ears was 0.70 mm (interquartile range [IQR]: 0.40-1.05 mm) versus 2.00 mm in non-CAS ears (IQR: 1.80-2.30 mm, P < .001). CND was found in 98.5% (n = 64/65) of CAS ears, while a normal cochlear nerve was found in 1.5% (n = 1/65) of CAS ears.

CONCLUSION

CND is highly prevalent among pediatric patients with CAS. This suggests that MRI may not be needed to assess for CND in USNHL patients with CAS, as initial CT may provide sufficient information to determine cochlear implant candidacy. We recommend thoughtful shared decision-making with parents of USNHL patients when determining whether to pursue MRI in the setting of a CAS diagnosis.

Comparing pronunciation challenges in South Korean preschoolers with unilateral single-sided deafness due to cochlear nerve deficiency to a norm-referenced standard

This study aimed to compare the development of pronunciation in South Korean preschoolers with unilateral cochlear nerve deficiency (CND) to that of age-matched preschoolers with normal hearing, a topic that has not been explored previously. In a retrospective analysis, 25 preschoolers with unilateral CND who had undergone a speech evaluation battery, including a pronunciation and vocabulary test, were enrolled. Utilizing the Urimal Test of Articulation and Phonation and customized language ability tests, pronunciation and vocabulary were assessed. The subjects' speech evaluation scores were converted into age-adjusted z-scores using normal controls' data. While vocabulary performance was within normal limits, their average pronunciation z-score was -2.90, significantly lower than both the zero reference point and their vocabulary z-scores. None of the subjects scored above average in pronunciation. Thirteen patients were recommended for articulation therapy, seven were considered as potential candidates for this therapy, and the remaining five were within normal limits. There was no observed correlation between the development of pronunciation and vocabulary. Notably, some subjects' pronunciation scores did not improve, even after serial follow-up during their preschool years. Despite typical vocabulary development, preschoolers with unilateral CND exhibit significant delays in pronunciation. These findings emphasize the necessity for vigilant monitoring of their language development.

Single-Sided Deafness and Hearing Rehabilitation Modalities: Contralateral Routing of Signal Devices, Bone Conduction Devices, and Cochlear Implants

Single sided deafness (SSD) is characterized by significant sensorineural hearing loss, severe or profound, in only one ear. SSD adversely affects various aspects of auditory perception, including causing impairment in sound localization, difficulties with speech comprehension in noisy environments, and decreased spatial awareness, resulting in a significant decline in overall quality of life (QoL). Several treatment options are available for SSD, including cochlear implants (CI), contralateral routing of signal (CROS), and bone conduction devices (BCD). The lack of consensus on outcome domains and measurement tools complicates treatment comparisons and decision-making. This narrative overview aims to summarize the treatment options available for SSD in adult and pediatric populations, discussing their respective advantages and disadvantages. Rerouting devices (CROS and BCD) attenuate the effects of head shadow and improve sound awareness and signal-to-noise ratio in the affected ear; however, they cannot restore binaural hearing. CROS devices, being non-implantable, are the least invasive option. Cochlear implantation is the only strategy that can restore binaural hearing, delivering significant improvements in speech perception, spatial localization, tinnitus control, and overall QoL. Comprehensive preoperative counseling, including a discussion of alternative technologies, implications of no treatment, expectations, and auditory training, is critical to optimizing therapeutic outcomes.

Etiology, Severity, Audiogram Type, and Device Usage in Patients with Unilateral Moderate to Profound Sensorineural Hearing Loss in Japan

BACKGROUND

Few studies have reported on the etiology, severity, or device usage of unilateral sensorineural hearing loss (UHL) compared to bilateral hearing loss. Therefore, this study investigated the characteristics of UHL in adults and children.

METHODS

We performed a survey using questionnaires for secondary and tertiary otolaryngology institutions.

RESULTS

We included 15,981 patients (1549 children and 14,432 adults) from 196 institutions with otolaryngology residency programs and 2844 patients (336 children and 2508 adults) from 27 institutions with board members of the Japan Audiology Society. The latter submitted audiological data. Among children, most diagnoses were made at age 0. Approximately half of them had profound hearing loss, and 37 children (2.2%) used hearing devices. Among adults, the number of cases increased with age, but decreased when people reached their 80s and 90s. More than half of them had moderate hearing loss. Sudden sensorineural hearing loss was the most common cause of UHL of all ages; 4.4% of UHL patients used hearing devices, and most of the device users (98.6%) selected a conventional hearing aid.

CONCLUSIONS

Hearing aid use is limited in children and adults with UHL in Japan. There could be many candidates with UHL for intervention such as a cochlear implant.

Prevalence of Cochlear Nerve Deficiency and Hearing Device Use in Children With Single-Sided Deafness

OBJECTIVE

This study aimed to assess the prevalence of cochlear nerve deficiency (CND) in a cohort of pediatric patients with single-sided deafness (SSD). A secondary objective was to investigate trends in intervention and hearing device use in these children.

STUDY DESIGN

Case series with chart review.

SETTING

Pediatric tertiary care center.

METHODS

Children ages 0 to 21 years with SSD (N = 190) who underwent computerized tomography (CT) and/or magnetic resonance imaging (MRI) were included. Diagnostic criteria for SSD included unilateral severe-to-profound sensorineural hearing loss with normal hearing sensitivity in the contralateral ear. Diagnostic criteria for CND included neuroradiologist report of an "aplastic or hypoplastic nerve" on MRI or a "stenotic cochlear aperture" on CT.

RESULTS

The prevalence of CND was 42% for children with CT only, 76% for children with MRI only, and 63% for children with both MRI and CT. Of the children with MRI and CT, there was a 90% concordance across imaging modalities. About 36% of children with SSD had hearing devices that routed sound to the normal hearing ear (ie, bone conduction hearing device/contralateral routing of signal), while only 3% received a cochlear implant. Approximately 40% did not have a hearing device. Hearing device wear time averaged 2.9 hours per day and did not differ based on cochlear nerve status.

CONCLUSION

There is a high prevalence of CND in children with SSD. Cochlear nerve status should be confirmed via MRI in children with SSD. The limited implementation and use of hearing devices observed for children with SSD reinforce the need for increased support for early and continuous intervention.

Cochlear nerve dysplasia in unilateral severe to profound congenital sensorineural hearing loss - Prevalence in Australian children and the impact of socioeconomic disadvantage on its management

INTRODUCTION

Congenital unilateral sensorineural hearing loss (cuSNHL) carries potentially significant social, educational, and developmental consequences. Early diagnosis enables investigation, and consideration of options for management and early intervention, helping to mitigate the effects of hearing loss. Cochlear nerve dysplasia (CND) is a prominent cause of cuSNHL and may affect candidacy for cochlear implantation. Socioeconomic disadvantage may impact on a patient's family's capacity to participate in necessary intervention and follow-up.

METHODS

Infants with severe-profound cuSNHL referred to a large Australian quaternary pediatric center between October 2004 and December 2020 were retrospectively included. Audiometric and clinical data, and the presence of hearing loss risk factors were obtained from a prospectively collated database. In Australia MRI scans are provided free-of-charge to citizens and residents. MRI scans were reviewed to determine the status of the nerves within the internal acoustic meatus (IAM grade) along with attendance rates. Travel distance to the hospital was also calculated. Reasons for non-attendance at MRI were obtained from patient medical records and correspondence. Socioeconomic, educational, and occupational indices, and travel distances were obtained using patient residential postcodes with reference to Australian Bureau of Statistics data.

RESULTS

A total of 98 patients were reviewed, 64.3% (n = 63) of whom underwent MRI. The median age at diagnosis was 40 days (IQR 27). The prevalence of CND was 75% (n = 47). Importantly, there was no significant difference in the degree of hearing loss between IAM grades (F(4,57) = 1.029, p = 0.405). Socioeconomic indices were significantly lower in patients not attending MRI investigations compared with patients who did attend. Travel distance was not significantly different between the two groups.

CONCLUSION

CND is a prominent cause of cuSNHL in Australian infants. MRI at a young age allows parent education regarding management options and timely intervention where indicated. Socioeconomic disadvantage significantly impacts on participation in further routine assessment of cuSNHL, potentially limiting management options for these children long term.

Effect of Hearing Device Use on Speech-in-Noise Performance in Children with Severe-to-Profound Unilateral Hearing Loss

OBJECTIVES

Limited evidence exists for the use of rerouting devices in children with severe-to-profound unilateral sensorineural hearing loss. Many laboratory studies to date have evaluated hearing-in-noise performance in specific target-masker spatial configurations within a small group of participants and with only a subset of available hearing devices. In the present study, the efficacy of all major types of nonsurgical devices was evaluated within a larger group of pediatric subjects on a challenging speech-in-noise recognition task.

DESIGN

Children (7-18 years) with unaided severe-to-profound unilateral hearing loss (UHL' n = 36) or bilateral normal hearing (NH, n = 36) participated in the present study. The signal-to-noise ratio (SNR) required for 50% speech understanding (SNR-50) was measured using BKB sentences in the presence of proprietary restaurant noise (R-SPACE BSIN-R) in the R-SPACE Sound System. Subjects listened under 2 target/masker spatial configurations. The target signal was directed toward subjects' NH or hearing-impaired ear (45º azimuth), while the interfering restaurant noise masker was presented from the remaining 7 loudspeakers encircling the subject, spaced every 45º. Head position was fixed during testing. The presentation level of target sentences and masking noise varied over time to estimate the SNR-50 (dB). The following devices were tested in all participants with severe-to-profound UHL: air conduction (AC) contralateral routing of signal (CROS), bone conduction (BC) CROS fitted on a headband with and without the use of remote microphone (RM), and an ear-level RM hearing assistance technology (HAT) system.

RESULTS

As a group, participants with severe-to-profound UHL performed best when the target signal was directed toward their NH ear. Across listening conditions, there was an average 8.5 dB improvement in SNR-50 by simply orienting the NH ear toward the target signal. When unaided, participants with severe-to-profound UHL performed as well as participants with NH when the target signal was directed toward the NH ear. Performance was negatively affected by AC CROS when the target signal was directed toward the NH ear, whereas no statistically significant change in performance was observed when using BC CROS. When the target signal was directed toward participants' hearing-impaired ear, all tested devices improved SNR-50 compared with the unaided condition, with small improvements (1-2 dB) observed with CROS devices and the largest improvement (9 dB) gained with the personal ear-level RM HAT system. No added benefit nor decrement was observed when RM was added to BC CROS using a 50/50 mixing ratio when the target was directed toward the impaired ear.

CONCLUSIONS

In a challenging listening environment with diffuse restaurant noise, SNR-50 was most improved in the study sample when using a personal ear-level RM HAT system. Although tested rerouting devices offered measurable improvement in performance (1-2 dB in SNR-50) when the target was directed to the impaired ear, benefit may be offset by a detriment in performance in the opposing condition. Findings continue to support use of RM HAT for children with severe-to-profound UHL in adverse listening environments, when there is one primary talker of interest, to ensure advantageous SNRs.

Task force Guideline of Brazilian Society of Otology - hearing loss in children - Part II - Treatment

OBJECTIVES

To provide an overview of the main evidence-based recommendations for the diagnosis of hearing loss in children and adolescents aged 0-18 years.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on childhood hearing loss were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) treatment of sensorineural hearing loss: individual hearing aids, bilateral cochlear implants, cochlear implants in young children, unilateral hearing loss, and auditory neuropathy spectrum disorder; and (2) treatment of conductive/mixed hearing loss: external/middle ear malformations, ventilation tube insertion, and tympanoplasty in children.

CONCLUSIONS

In children with hearing loss, in addition to speech therapy, Hearing AIDS (HAs) or implantable systems may be indicated. Even in children with profound hearing loss, both the use of HAs and behavioral assessments while using the device are important.

Novel Molecular Genetic Etiology of Asymmetric Hearing Loss: Autosomal-Dominant LMX1A Variants

INTRODUCTION

Sensorineural hearing loss is the most common sensory disorder in humans. Genetic analyses have greatly increased our understanding of the pathogenic mechanisms in play. Thus, characterization of audiologic phenotypes by the genetic etiology may aid elucidation of the etiologies of certain types of inherited hearing loss. Further, delineation of specific audiologic phenotypes based on the genetic etiology aids our understanding of some types of inherited hearing loss in terms of the prediction of clinical course, revelation of genotype-phenotype correlations, and application of appropriate audiologic rehabilitation. Here, we describe the interesting audiologic characteristics of LMX1A -associated deafness, which revealed significant asymmetry between two ears.

METHODS

Among 728 probands of which genomic DNA went through exome sequencing regardless of any specific audiologic phenotypes, probands for which exome sequencing was performed and a causative LMX1A variant was found were all included. Five LMX1A -associated DFNA7 families (approximately 0.7%), the pedigrees of whom indicated autosomal-dominant hearing loss, were identified, and segregation was studied using Sanger sequencing. The affected individuals underwent comprehensive evaluations, including medical history reviews, physical examinations, imaging, and auditory phenotyping. We functionally characterized the novel LMX1A variants via computational structural modeling and luciferase reporter assays.

RESULTS

Among 728 probands of which genomic DNA went through exome sequencing, we identified four novel LMX1A heterozygous variants related to DFNA7 (c.622C>T:p.Arg208*, c.719A>G:p.Gln240Arg, c.721G>A:p.Val241Met, and c.887dup:p.Gln297Thrfs*41) and one harboring a de novo heterozygous missense LMX1A variant (c.595A>G;p.Arg199Gly) previously reported. It is important to note that asymmetric hearing loss was identified in all probands and most affected individuals, although the extent of asymmetry varied. Structural modeling revealed that the two missense variants, p.Gln240Arg and p.Val241Met, affected conserved residues of the homeodomain, thus attenuating LMX1A-DNA interaction. In addition, Arg208*-induced premature termination of translation destroyed the structure of the LMX1A protein, including the DNA-binding homeodomain, and p.Gln297Thrfs*41 led to the loss of the C-terminal helix involved in LIM2 domain interaction. Compared with the wild-type protein, all mutant LMX1A proteins had significantly reduced transactivation efficiency, indicating that the ability to elicit transcription of the downstream target genes of LMX1A was severely compromised. Thus, in line with the American College of Medical Genetics and Genomics guideline specified to genetic hearing loss, the four novel LMX1A variants were identified as "pathogenic" (p.Arg208* and p.Gln297Thrfs*41), "likely pathogenic" (p.Val241Met), and as a "variant of uncertain significance'' (p.Gln240Arg).

CONCLUSION

For the first time, we suggest that LMX1A is one of the candidate genes which, if altered, could be associated with dominantly inherited asymmetric hearing loss. We also expand the genotypic spectrum of disease-causing variants of LMX1A causing DFNA7 by doubling the number of LMX1A variants reported thus far in the literature.

Auditory perception in pediatric cochlear implant users with cochlear nerve hypoplasia

OBJECTIVES

The objectives of this study were to assess auditory perception and speech intelligibility outcomes in children with cochlear nerve (CN) hypoplasia who received cochlear implants (CIs) using Categories of Auditory Performance II (CAP II) and Speech Intelligibility Rating (SIR) scales.

METHODS

In total, 40 children who received CI and who were aged between 3 and 18 years were included in this study. The study group included 20 children with CN hypoplasia at least one ear, while the control group included 20 children with normal cochleas and cochlear nerve structures. All children in the study and control groups who participated were evaluated using the CAP II and the SIR scale. Demographic data were collected.

RESULTS

Significant differences were found between the study and control groups' CAP II and SIR scores (p < 0.001). It was found that CAP II scores were positively correlated with SIR scores in the study (r = 0.743, p < 0.001) and control (r = 0.601, p < 0.001) groups. In the study group, significant negative correlations were found between SIR scores and age at implantation (r = -0.674, p = 0.004) and between CAP II scores and age at implantation (r = 0.751, p = 0.003). In the control group, a significant negative correlation was found between age at implantation and CAP II scores (r = -0.805, p = 0.001). Similarly, a significant negative correlation was found between age at implantation and SIR scores (r = -0.702, p = 0.007).

CONCLUSION

Even for children with severe inner ear malformation and CN hypoplasia, CI is an effective treatment modality for auditory perception and speech production. However, it should be noted that CN hypoplasia affects auditory performance negatively in children with CI.

Assessment of the correlation between residual hearing and audiologic outcomes after cochlear implantation in patients with cochlear nerve deficiency

Objective

This study aimed to assess the correlation between residual hearing and audiologic outcomes after cochlear implant (CI) surgery in patients with cochlear nerve deficiency (CND).

Methods

This retrospective study included 57 patients with CND who underwent CI surgery. Patients were divided into four groups according to hearing level (80–95, 95–110, 110–120, and >120 dB) and three groups according to residual hearing (entire spectrum hearing, partial spectrum hearing, and no spectrum hearing) based on the measured response at each frequency. Auditory performance (categorical auditory performance [CAP], Infant–Toddler Meaningful Auditory Integration Scale [IT‐MAIS]) and speech perception (speech intelligibility rating [SIR] and meaningful use of speech scale [MUSS]) were assessed before and 2 years after the surgery.

Results

Forty‐seven (82.5%) patients had complete or total hearing loss (≥95 dB) and 17 (29.8%) had no spectrum hearing before CI surgery. Twenty‐nine (50.9%) patients did not exhibit residual hearing at 4 kHz. All patients demonstrated an improvement in auditory performance and speech perception: the CAP score in the 80–95 dB group was significantly higher than that in the 110–120 and >120 dB groups, and the entire spectrum hearing group showed significantly higher CAP, SIR, and IT‐MAIS scores than the partial spectrum hearing group and significantly higher CAP, SIR, IT‐MAIS, and MUSS scores than the no spectrum hearing group.

Conclusion

For patients with CND, residual hearing, especially high‐frequency residual hearing, was poor and postoperative audiologic outcomes were significantly associated with the range of residual hearing.

Level of Evidence

4

A Prospective Study of Etiology and Auditory Profiles in Infants with Congenital Unilateral Sensorineural Hearing Loss

Congenital unilateral sensorineural hearing loss (uSNHL) is associated with speech-language delays and academic difficulties. Yet, controversy exists in the choice of diagnosis and intervention methods. A cross-sectional prospective design was used to study hearing loss cause in twenty infants with congenital uSNHL consecutively recruited from a universal neonatal hearing-screening program. All normal-hearing ears showed ≤20 dB nHL auditory brainstem response (ABR) thresholds (ABRthrs). The impaired ear median ABRthr was 55 dB nHL, where 40% had no recordable ABRthr. None of the subjects tested positive for congenital cytomegalovirus (CMV) infection. Fourteen subjects agreed to participate in magnetic resonance imaging (MRI). Malformations were common for all degrees of uSNHL and found in 64% of all scans. Half of the MRIs demonstrated cochlear nerve aplasia or severe hypoplasia and 29% showed inner ear malformations. Impaired ear and normal-hearing ear ABR input/output functions on a group level for subjects with ABRthrs < 90 dB nHL were parallel shifted. A significant difference in interaural acoustic reflex thresholds (ARTs) existed. In congenital uSNHL, MRI is powerful in finding a possible hearing loss cause, while congenital CMV infection may be relatively uncommon. ABRs and ARTs indicated an absence of loudness recruitment, with implications for further research on hearing devices.

Machine Learning-Based Prediction of the Outcomes of Cochlear Implantation in Patients With Cochlear Nerve Deficiency and Normal Cochlea: A 2-Year Follow-Up of 70 Children

Cochlear nerve deficiency (CND) is often associated with variable outcomes of cochlear implantation (CI). We assessed previous investigations aiming to identify the main factors that determine CI outcomes, which would enable us to develop predictive models. Seventy patients with CND and normal cochlea who underwent CI surgery were retrospectively examined. First, using a data-driven approach, we collected demographic information, radiographic measurements, audiological findings, and audition and speech assessments. Next, CI outcomes were evaluated based on the scores obtained after 2 years of CI from the Categories of Auditory Performance index, Speech Intelligibility Rating, Infant/Toddler Meaningful Auditory Integration Scale or Meaningful Auditory Integration Scale, and Meaningful Use of Speech Scale. Then, we measured and averaged the audiological and radiographic characteristics of the patients to form feature vectors, adopting a multivariate feature selection method, called stability selection, to select the features that were consistent within a certain range of model parameters. Stability selection analysis identified two out of six characteristics, namely the vestibulocochlear nerve (VCN) area and the number of nerve bundles, which played an important role in predicting the hearing and speech rehabilitation results of CND patients. Finally, we used a parameter-optimized support vector machine (SVM) as a classifier to study the postoperative hearing and speech rehabilitation of the patients. For hearing rehabilitation, the accuracy rate was 71% for both the SVM classification and the area under the curve (AUC), whereas for speech rehabilitation, the accuracy rate for SVM classification and AUC was 93% and 94%, respectively. Our results identified that a greater number of nerve bundles and a larger VCN area were associated with better CI outcomes. The number of nerve bundles and VCN area can predict CI outcomes in patients with CND. These findings can help surgeons in selecting the side for CI and provide reasonable expectations for the outcomes of CI surgery.

Vestibular and radiological characteristics of children affected by unilateral auditory neuropathy spectrum disorder

OBJECTIVE

Auditory neuropathy spectrum disorders (ANSD) are defined by the association of a preserved outer hair cell function and an impaired auditory nerve neural response, and present mostly bilaterally. Unilateral ANSD are consequently only seldom described, and most frequently as isolated cases. This study aims to describe the audiological, vestibular and radiological characteristics of a population of children with unilateral ANSD.

MATERIAL AND METHODS

We isolated 22 patients with unilateral ANSD, 12 boys and 10 girls from 0 to 95 months, in a database of auditory evoked potentials. We reviewed the audiological, radiological and vestibular assessments. The audiological assessment included tympanometry, otoacoustic emission recording and auditory evoked potential. Otolithic function was assessed by performing cervical vestibular evoked myogenic potential. The canal function was determined by video head impulse test and/or caloric test. The radiological evaluation consisted of an MRI of the internal auditory canal.

RESULTS

Many patients with a type A tympanometry had no response to otoacoustic emission (53,8%), in the presence of a cochlear microphonic potential. Vestibular assessment was performed in 9 of the 22 patients. 4 children had impaired otolithic and/or canal function. MRI evaluation of the inner ear was performed in 18 patients. Aplasia or hypoplasia of the cochlear nerve was found in 17 of them. MRI showed additional vestibular or brainstem abnormalities in 7 of the 18 children. All children with impaired vestibular function had vestibular or brainstem radiological alterations in addition to cochlear branch aplasia or hypoplasia.

CONCLUSIONS

Radiological and vestibular abnormalities are common in children with unilateral ANSD and suggest that a radiological and vestibular assessment is required.

Audiological Features in 63 Patients With Cochlear Nerve Deficiency

OBJECTIVE

We aimed to investigate the clinical features of cochlear nerve deficiency (CND), and in particular, the long-term course of hearing disability and audiogram shapes.

STUDY DESIGN

Retrospective observational nonrandomized group study.

SETTING

Academic medical center.

PATIENTS/INTERVENTIONS

The subjects were 63 children with congenital hearing loss who visited our hospital between 2009 and 2019 and underwent MRI, based on which they were diagnosed with CND. There were 61 cases of unilateral CND and two cases of bilateral CND.

MAIN OUTCOME MEASURES

Imaging tests by MRI and CT and audiometric assessments by pure-tone audiometry and distortion product otoacoustic emission were performed.

RESULTS

Among the cases of CND diagnosed by assessing the cochlear nerve on MRI, approximately 20% of the bony cochlear nerve canals that could be assessed on CT were normal. Of the 61 cases diagnosed with unilateral CND, 55 cases had cochlear nerve aplasia (90.2%), and six had cochlear nerve hypoplasia (9.8%), with a mean hearing ability of 92.2 and 94.6 dB HL, respectively. Thus, the majority of cases had severe-to-profound hearing loss. The overall audiometric patterns were 78.7% flat, 9.8% cookie-bite, and 9.8% high-frequency. Six of 61 cases (9.8%) had a distortion product otoacoustic emission (DPOAE) response based on the affected side, and none of the cases lost the response during follow-up.

CONCLUSIONS

Herein, we report the largest study on CND and performed CND image and audiometric assessments. Accurately in diagnosing CND requires not only CT but also MRI assessment. Hearing loss is often severe to profound; however, various audiometric patterns have been observed. CND includes a small number of cases that respond to DPOAE, indicating that some CND cases are clinically diagnosed with auditory neuropathy spectrum disorder (ANSD). A sustained DPOAE response might help in differentiating CND from other ANSDs. Children with congenital deafness who have passed the newborn hearing screening by DPOAE should be examined by MRI to rule out CND.

Clinical Test Batteries to Diagnose Hearing Loss in Infants and Children: The Cross-Check Principle

Frequency-specific audiometry and tympanometry are widely considered the foundation of the pediatric hearing evaluation. However, additional behavioral and objective measures are needed to cross-check findings and ensure an accurate and timely diagnosis. This is particularly important in the pediatric population, wherein a delay in diagnosis can have a significant impact on language development, learning, and educational outcomes. The following discussion emphasizes the importance of performing a comprehensive test battery in the pediatric audiology clinic through 5 unique case studies.

Congenital Unilateral Hearing Loss: Characteristics and Etiological Analysis in 121 Patients

OBJECTIVE

To describe the characteristics and etiological analysis in patients with congenital unilateral hearing loss.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary referral center.

PATIENTS

Children with permanent congenital unilateral hearing loss born between 2007 and 2018. Patients were referred after universal newborn hearing screening or by a colleague to confirm the diagnosis and perform etiological examinations.

MAIN OUTCOME MEASURES

Hearing loss type, severity, and evolution linked with the results of etiological testing.

RESULTS

In the 121 included children, aural atresia is the leading cause of congenital unilateral hearing loss (32%), followed by structural anomalies (19%) and cCMV (13%), whereas 24% remained idiopathic after etiological work-up. Severity is mainly moderately severe (33% with 56-70 dB hearing loss, majority aural atresia) or profound (31% with > 90 dB hearing loss, predominantly cochlear nerve deficiency). Syndromic features were present in 26%. Although discussed with all parents, only 26% of the children regularly used hearing amplification.

CONCLUSIONS

Congenital conductive unilateral hearing loss is mainly caused by aural atresia, which proportion in congenital unilateral hearing loss proved higher than previously reported. Cochlear nerve deficiency and cCMV are the predominant etiologies of congenital unilateral sensorineural hearing loss. Etiological work-up in affected patients is mandatory as it might impact the approach, and syndromic features should be actively searched for.

Vestibular nerve deficiency and vestibular function in children with unilateral hearing loss caused by cochlear nerve deficiency

BACKGROUND

High-resolution MR imaging enables the visualization of individual nerves in the internal auditory canal (IAC). Cochlear nerve deficiency (CND) is recognized as one of the major causes of sensory neural hearing loss (SNHL), especially in cases of unilateral hearing loss in childhood. Some patients with CND are thought to have accompanying vestibular nerve deficiency (VND). However, there have been few reports focusing on VND and vestibular function in these children.

AIMS

The aim of this study was to evaluate the frequency of VND and vestibular dysfunction in children with unilateral SNHL caused by CND.

MATERIAL AND METHODS

Thirty-eight children with unilateral SNHL, who were diagnosed with CND by 3 T-MRI, were evaluated for VND and underwent caloric testing and cervical vestibular evoked potential (cVEMP).

RESULTS

Fourteen of 38 patients (37%) had VND, and eleven (29%) of the patients [ten of the patients (71%) with VND] had at least one vestibular dysfunction. The patients with VND had significantly worse hearing and an IAC of smaller diameter than did patients without VND.

CONCLUSIONS AND SIGNIFICANCE

We should pay attention to VND as well as vestibular dysfunction in hearing loss patients with CND.

A Porcine Congenital Single-Sided Deafness Model, Its Population Statistics and Degenerative Changes

Objective

To describe and study the population statistics, hearing phenotype, and pathological changes of a porcine congenital single-sided deafness (CSSD) pedigree.

Methods

Click auditory brainstem response (ABR), full-frequency ABR, and distortion product otoacoustic emission (DPOAE) were used to assess the hearing phenotype of the strain. Tympanogram was used to assess the middle ear function since birth. Celloidin embedding-hematoxylin-eosin (CE-HE) stain and scanning electron microscopy (SEM) were used to study the pathological changes of cochlear microstructures. Chi-square analysis was used to analyze the relation between hearing loss and other phenotypes.

Results

The mating mood of CSSD with CSSD was most efficient in breeding-targeted CSSD phenotype (47.62%), and the prevalence of CSSD reached 46.67% till the fifth generation, where 42.22% were bilateral hearing loss (BHL) and 9.00% were normal hearing (NH) individuals. Hearing loss was proved to have no relation with coat color (P = 0.0841 > 0.05) and gender (P = 0.4621 > 0.05) by chi-square analysis. The deaf side of CSSD offspring in the fifth generation had no relation with that of their maternal parent (P = 0.2387 > 0.05). All individuals in this strain exhibited congenital severe to profound sensorineural hearing loss with no malformation and dysfunction of the middle ear. The good hearing ear of CSSD stayed stable over age. The deaf side of CSSD and BHL presented cochlear and saccular degeneration, and the hair cell exhibited malformation since birth and degenerated from the apex to base turn through time. The pathology in BHL cochlea progressed more rapidly than CSSD and till P30, the hair cell had been totally gone. The stria vascularis (SV) was normal since birth and degenerated through time and finally exhibited disorganization of three layers of cells.

Conclusion

This inbred porcine strain exhibited high and stable prevalence of CSSD, which highly resembled human non-syndromic CSSD disease. This porcine model could be used to further explore the etiology of CSSD and serve as an ideal tool for the studies of the effects of single-sided hearing deprivation on neural, cognitive, and behavioral developments and the benefits brought by CI in CSSD individuals.

Pediatric Single-Sided Deafness: A Review of Prevalence, Radiologic Findings, and Cochlear Implant Candidacy

OBJECTIVE

To characterize the prevalence, imaging characteristics, and cochlear implant candidacy of pediatric patients with single-sided deafness (SSD).

METHODS

An audiometric database of patients evaluated at a large tertiary academic medical center was retrospectively queried to identify pediatric patients (<18 years old) with SSD, defined as severe to profound sensorineural hearing loss in one ear and normal hearing in the other. Medical records of identified patients were reviewed to characterize the prevalence, etiology, and cochlear implant candidacy of pediatric patients with SSD.

RESULTS

We reviewed audiometric data obtained from 1993 to 2018 for 52,878 children at our institution. 191 (0.36%) had the diagnosis of SSD. Cochlear nerve deficiency (either hypoplasia or aplasia) diagnosed on MRI and/or CT was the most common etiology of SSD and was present in 22 of 88 (25%) pediatric SSD patients with available imaging data. 70 of 106 (66%) pediatric SSD patients with available imaging had anatomy amenable to cochlear implantation.

CONCLUSIONS

Pediatric SSD is a rare condition and the most common etiology based on radiology is cochlear nerve deficiency. High resolution imaging of the temporal bone is essential to determine cochlear nerve morphology prior to consideration of cochlear implantation.

Cochlear nerve anomalies in paediatric single-sided deafness - prevalence and implications for cochlear implantation strategies

OBJECTIVE

To determine the prevalence of cochlear nerve anomalies on magnetic resonance imaging in patients with unilateral or bilateral sensorineural hearing loss.

METHODS

A retrospective case series was conducted at a tertiary referral centre. The inclusion criteria were paediatric patients with bilateral or unilateral sensorineural hearing loss, investigated with magnetic resonance imaging. The primary outcome measure was the rate of cochlear nerve hypoplasia or aplasia.

RESULTS

Of the 72 patients with unilateral sensorineural hearing loss, 39 per cent (28 cases) had absent or hypoplastic cochlear nerves on the affected side. Fifteen per cent (11 cases) had other abnormal findings on magnetic resonance imaging. Eighty-four patients had bilateral sensorineural hearing loss, of which cochlear nerve hypoplasia or aplasia was identified only in 5 per cent (four cases). Other abnormal findings were identified in 14 per cent (12 cases).

CONCLUSION

Paediatric patients with unilateral sensorineural hearing loss are more likely to have cochlear nerve anomalies than those patients with bilateral sensorineural hearing loss. This has important implications regarding cochlear implantation for patients with single-sided deafness.

Prediction of the Functional Status of the Cochlear Nerve in Individual Cochlear Implant Users Using Machine Learning and Electrophysiological Measures

OBJECTIVES

This study aimed to create an objective predictive model for assessing the functional status of the cochlear nerve (CN) in individual cochlear implant (CI) users.

DESIGN

Study participants included 23 children with cochlear nerve deficiency (CND), 29 children with normal-sized CNs (NSCNs), and 20 adults with various etiologies of hearing loss. Eight participants were bilateral CI users and were tested in both ears. As a result, a total of 80 ears were tested in this study. All participants used Cochlear Nucleus CIs in their test ears. For each participant, the CN refractory recovery function and input/output (I/O) function were measured using electrophysiological measures of the electrically evoked compound action potential (eCAP) at three electrode sites across the electrode array. Refractory recovery time constants were estimated using statistical modeling with an exponential decay function. Slopes of I/O functions were estimated using linear regression. The eCAP parameters used as input variables in the predictive model were absolute refractory recovery time estimated based on the refractory recovery function, eCAP threshold, slope of the eCAP I/O function, and negative-peak (i.e., N1) latency. The output variable of the predictive model was CN index, an indicator for the functional status of the CN. Predictive models were created by performing linear regression, support vector machine regression, and logistic regression with eCAP parameters from children with CND and the children with NSCNs. One-way analysis of variance with post hoc analysis with Tukey's honest significant difference criterion was used to compare study variables among study groups.

RESULTS

All three machine learning algorithms created two distinct distributions of CN indices for children with CND and children with NSCNs. Variations in CN index when calculated using different machine learning techniques were observed for adult CI users. Regardless of these variations, CN indices calculated using all three techniques in adult CI users were significantly correlated with Consonant-Nucleus-Consonant word and AzBio sentence scores measured in quiet. The five oldest CI users had smaller CN indices than the five youngest CI users in this study.

CONCLUSIONS

The functional status of the CN for individual CI users was estimated by our newly developed analytical models. Model predictions of CN function for individual adult CI users were positively and significantly correlated with speech perception performance. The models presented in this study may be useful for understanding and/or predicting CI outcomes for individual patients.

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

INTRODUCTION

The 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.

METHODS

Retrospective case series for pediatric SSD from 2008 to 2018.

RESULTS

88 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.

CONCLUSIONS

Despite 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.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

[Common clinical causes and audiological manifestations of unilateral hearing loss in children]

Objective:To analyze the common clinical causes and audiological manifestations of unilateral hearing loss in children, and to provide a basis for early prevention and intervention. Method:A retrospective analysis of 20 cases of children diagnosed with unilateral hearing loss was conducted. The medical history was collected, followed by audiological and imaging examinations. Result:The audiological performance of 20 children with unilateral hearing loss: 1 case of conductive deafness, whose hearing curve was flat and showed moderate hearing loss. There were 19 cases of sensorineural deafness, of which 1 case was moderate deafness, 16 cases were severe deafness, and 2 cases were extremely severe deafness. The imaging results showed that there were 1 case with transverse fracture of the temporal bone, 1 case with congenital cholesteatoma, 9 cases with dysplasia of the cochlear nerve, and 4 cases with malformation of the inner ear. The history of the two children was collected and there were clear congenital cytomegalovirus infection and mumps virus infection. The causes of the remaining 3 cases were unknown. Conclusion:Unilateral hearing loss in children is a common clinical diseasewith complex and diverse causes. Carefully analysis should be made to find out the causes and symptomatic treatment to provide a basis for early prevention and intervention of children's hearing.

Comprehensive hearing care network for early identification and intervention in children with congenital and late-onset/acquired hearing loss: 8 years' experience in Miyazaki

OBJECTIVE

In 2010, we established the Miyazaki Comprehensive Hearing Care Network (MCHCN) for early identification and intervention in children with congenital and late-onset/acquired hearing loss with the cooperation of related administrative bodies in Miyazaki prefecture. The central roles of the MCHCN program are played by the Hearing Care Center (HCC) at the University of Miyazaki Hospital established in 2010 to facilitate audiological diagnoses, hearing aid interventions, and educational efforts, as well as linkage with the Department of Otolaryngology for surgical interventions. Herein, we aimed to present the main outcomes of the MCHCN program organized by the HCC at the University of Miyazaki Hospital.

METHODS

The MCHCN consists of two different networks, the Newborn Hearing Screening Network (NHSN) and the Pediatric Hearing Care Network (PHCN). All children suspected of having hearing loss by Newborn Hearing Screening (NHS) are referred to the HCC via the NHSN. In addition, children suspected of late-onset/acquired hearing loss by municipality-led health checkups, pediatricians, public health nurses, and childcare workers are referred to the HCC via the PHCN. Children who were born in Miyazaki prefecture between January 2010 and December 2017 and referred to the HCC for detailed hearing examination were included in this study.

RESULTS

Within the study period, 89,390 infants were born in Miyazaki prefecture, and 84,737 (94.9%) of them underwent NHS. A total of 698 infants and 182 children with suspected hearing loss were referred to the HCC via the NHSN and PHCN, respectively. Of the 880 referrals, 169 were diagnosed with hearing loss, which included 80 children with bilateral hearing loss and 89 children with unilateral hearing loss. Of the 80 children with bilateral hearing loss, 76 began wearing hearing aids and 15 had cochlear implants in the follow-up period. In children with bilateral conductive hearing loss, 4 children with bilateral middle ear anomalies underwent ossiculoplasty, following which two of these children no longer required hearing aids. Imaging assessments performed on 71 of the 89 children with unilateral hearing loss revealed that 20 of the 30 (66%) children who underwent CT exhibited ossicular anomalies and 28 out of the 48 (58%) children who underwent MRI were found to have ipsilateral cochlear nerve hypoplasia. Among the 169 children with hearing loss, no follow-up loss was observed during the period of this study.

CONCLUSION

The MCHCN that was organized at the initiative of the HCC at the University of Miyazaki Hospital has enabled the provision of comprehensive and continuous support, ranging from diagnosis to intervention, not only for children with suspected hearing loss referred based on their NHS results but also for those who pass the screening. Via this system, children with late-onset/acquired hearing loss can be identified early and can receive medical interventions tailored to the cause of their hearing loss while simultaneously avoiding a loss to follow-up.

Research Insights on Neural Effects of Auditory Deprivation and Restoration in Unilateral Hearing Loss: A Systematic Review

Neuroplasticity following bilateral deafness and auditory restoration has been repeatedly investigated. In clinical practice, however, a significant number of patients present a severe-to-profound unilateral hearing loss (UHL). To date, less is known about the neuroplasticity following monaural hearing deprivation and auditory input restoration. This article provides an overview of the current research insights on the impact of UHL on the brain and the effect of auditory input restoration with a cochlear implant (CI). An exhaustive systematic review of the literature was performed selecting 38 studies that apply different neural analyses techniques. The main results show that the hearing ear becomes functionally dominant after monaural deprivation, reshaping the lateralization of the neural network for auditory processing, a process that can be considered to influence auditory restoration. Furthermore, animal models predict that the onset time of UHL impacts auditory restoration. Hence, the results seem to advocate for early restoration of UHL, although further research is required to disambiguate the effects of duration and onset of UHL on auditory restoration and on structural neuroplasticity following UHL deprivation and restoration. Ongoing developments on CI devices compatible with Magnetic Resonance Imaging (MRI) examinations will provide a unique opportunity to investigate structural and functional neuroplasticity following CI restoration more directly.

Cochlear Implantation in Children with Single-Sided Deafness

OBJECTIVE

To describe our experience with children undergoing unilateral cochlear implantation (CI) for treatment of single-sided deafness (SSD).

STUDY DESIGN

Retrospective case series.

METHODS

A retrospective case review from a tertiary referral center involving 14 pediatric patients (<18 years) with SSD who underwent unilateral CI. Speech perception testing in quiet and noise in the CI-only and bimodal conditions with at least 1 year of device use and device usage from data logs represent the main outcome measures.

RESULTS

The mean age at CI was 5.0 years (median 4.4, range 1.0-11.8 years). The mean duration of deafness was 3.0 years (median 2.4, range 0.6-7.0 years). Mean follow-up was 3.4 years. Speech perception testing with a minimum of 1 year post-CI was available in eight patients. The mean word recognition scores (WRS) in the CI-only condition was 56%; a significant improvement from baseline. Testing in background noise with spatially separated speech and noise revealed that patients scored as well or better with the CI-on versus CI-off in all conditions and in no cases was interference from the CI noted. Data logs were reviewed for device usage which revealed an average use of 6.5 hr/d.

CONCLUSION

Cochlear implantation is a viable treatment option for pediatric SSD in this self-selected cohort. Open-set speech and improvement in background noise can be achieved. Careful patient selection and thorough counseling on expectations is paramount to achieving successful outcomes.

LEVEL OF EVIDENCE

IV Laryngoscope, 131:E271-E277, 2021.

Perda auditiva unilateral e assimétrica na infância

RESUMO Objetivo Descrever a perda auditiva sensorioneural unilateral e bilateral assimétrica em crianças quanto às características etiológicas, audiológicas e demográficas. Método Estudo retrospectivo transversal, desenvolvido na Seção de Implante Coclear do Hospital de Reabilitação de Anomalias Craniofaciais, por meio da análise de prontuários. Resultados Foram analisados os dados de 1152 pacientes, sendo 424 (37%) adolescentes, adultos ou idosos e 728 (63%) crianças, dentre as quais, 691 (95%) apresentavam perda auditiva bilateral simétrica e 37 (5%) perda auditiva sensorioneural unilateral (n=10) ou bilateral assimétrica (n=27). A idade média ao diagnóstico na perda auditiva sensorioneural unilateral foi de 33,58±21,69 meses e na bilateral assimétrica de 33,12±21,69 meses, com prevalência de 1,4% e 3,7%, respectivamente. O indicador de risco para a deficiência auditiva de maior ocorrência para ambos os grupos foi o de antecedente familiar. A maioria dos familiares das crianças com perda auditiva sensorioneural unilateral apresentaram a classificação socioeconômica baixa superior (50%), enquanto que as crianças com perda auditiva sensorioneural bilateral assimétrica se subdividiram igualmente em baixa superior (37%) e média inferior (37%). Conclusão Houve uma maior prevalência da perda auditiva sensorioneural bilateral assimétrica em relação à unilateral, bem como do indicador de risco de hereditariedade, com predomínio do grau profundo na pior orelha e preponderância do sexo feminino, em ambos os grupos. Apesar de a triagem auditiva neonatal propiciar a identificação precoce da perda auditiva sensorioneural unilateral, a idade no diagnóstico audiológico ainda se encontra acima do recomendado. Adicionalmente, a maioria dos familiares das crianças apresentou nível de rendimento baixo.

Early diagnosis and treatment of unilateral or asymmetrical hearing loss in children: CODEPEH recommendations

The aim of this document is to improve the management and the treatment of unilateral or asymmetrical hearing loss in children. One in one thousand newborn infants has unilateral hearing loss and this prevalence increases with age, due to cases of acquired and delayed-onset hearing loss. Although the impact on the development and learning processes of children of these kinds of hearing loss have usually been minimized, if they are not treated they will impact on language and speech development, as well as overall development, affecting the quality of life of the child and his/her family. The outcomes of the review are expressed as recommendations aimed at clinical diagnosis and therapeutic improvement for unilateral or asymmetrical hearing loss.

Clinical Value of Measurement of Internal Auditory Canal in Pediatric Cochlear Implantation

OBJECTIVES

The aims of this study were to clarify the clinical value of the bony cochlear nerve canal (BCNC) and internal auditory canal (IAC) in children with bilateral sensorineural hearing loss (b-SNHL) and to reveal the correlation between these parameters and outcomes after cochlear implantation (CI).

METHODS

Ninety-four ears with b-SNHL that received CI and 100 ears with normal hearing were enrolled. Parameters of IAC and pre- and post-CI categories of auditory performance scores were analyzed.

RESULTS

The width of the BCNC and the width, height, and length of the IAC were shorter in the b-SNHL group. BCNC and IAC width were associated with b-SNHL. The calculated cutoff values for BCNC and IAC width were 2.055 mm in the BCNC and 4.245 mm in the IAC, setting the sensitivity to 90%. Patients with narrow BCNCs and IACs had significantly worse post-CI auditory performance.

CONCLUSIONS

BCNC and IAC widths were narrower in children with b-SNHL than in normal-hearing children. Narrow BCNC and IAC width had a negative impact on post-CI outcomes. The proposed cutoff values for BCNC and IAC width were meaningful when predicting the auditory outcome after CI, especially considering both.

Assessment of the Clinical Benefit of Imaging in Children With Unilateral Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

IMPORTANCE

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.

OBJECTIVES

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.

EVIDENCE REVIEW

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.

MAIN OUTCOMES AND MEASURES

The pooled prevalence with 95% CI of inner ear abnormalities grouped according to finding and imaging modality.

FINDINGS

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.

CONCLUSIONS AND RELEVANCE

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.

Responsiveness of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency

OBJECTIVES

This study aimed to (1) investigate the responsiveness of the cochlear nerve (CN) to a single biphasic-electrical pulse in implanted children with cochlear nerve deficiency (CND) and (2) compare their results with those measured in implanted children with normal-size CNs.

DESIGN

Participants included 23 children with CND (CND1 to CND23) and 18 children with normal-size CNs (S1 to S18). All subjects except for CND1 used Cochlear Nucleus cochlear implants with contour electrode arrays in their test ears. CND1 was implanted with a Cochlear Nucleus Freedom cochlear implant with a straight electrode array in the test ear. For each subject, the CN input/output (I/O) function and the refractory recovery function were measured using electrophysiological measures of the electrically evoked compound action potential (eCAP) at multiple electrode sites across the electrode array. Dependent variables included eCAP threshold, the maximum eCAP amplitude, slope of the I/O function, and time-constants of the refractory recovery function. Slopes of I/O functions were estimated using statistical modeling with a sigmoidal function. Recovery time-constants, including measures of the absolute refractory period and the relative refractory period, were estimated using statistical modeling with an exponential decay function. Generalized linear mixed-effect models were used to evaluate the effects of electrode site on the dependent variables measured in children with CND and to compare results of these dependent variables between subject groups.

RESULTS

The eCAP was recorded at all test electrodes in children with normal-size CNs. In contrast, the eCAP could not be recorded at any electrode site in 4 children with CND. For all other children with CND, the percentage of electrodes with measurable eCAPs decreased as the stimulating site moved in a basal-to-apical direction. For children with CND, the stimulating site had a significant effect on the slope of the I/O functions and the relative refractory period but showed no significant effect on eCAP threshold and the maximum eCAP amplitude. Children with CND had significantly higher eCAP thresholds, smaller maximum eCAP amplitudes, flatter slopes of I/O functions, and longer absolute refractory periods than children with normal-size CNs. There was no significant difference in the relative refractory period measured in these two subject groups.

CONCLUSIONS

In children with CND, the functional status of the CN varied along the length of the cochlea. Compared with children with normal-size CNs, children with CND showed reduced CN responsiveness to electrical stimuli. The prolonged CN absolute refractory period in children with CND might account for, at least partially, the observed benefit of using relatively slow pulse rate in these patients.

Hearing Loss in Pediatric Septo-Optic Dysplasia

OBJECTIVE

To identify and characterize hearing loss (HL) in children with septo-optic dysplasia (SOD).

METHODS

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.

RESULTS

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).

CONCLUSIONS

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 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\bf{deduced}}:{\bf{CAP}}\,{\bf{score}}{\boldsymbol{=}}{\bf{0.7}}{\boldsymbol{+}}{\bf{1.9}}{\boldsymbol{\ast }}{\boldsymbol{(}}{\bf{ABR}}{\boldsymbol{)}}{\boldsymbol{+}}{\bf{1.2}}{\boldsymbol{\ast }}(\frac{{\boldsymbol{V}}{\boldsymbol{C}}{\boldsymbol{N}}}{{\boldsymbol{F}}{\boldsymbol{N}}})$$\end{document}deduced:CAPscore=0.7+1.9∗(ABR)+1.2∗(VCNFN). 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.

Unilateral congenital hearing loss in children: Challenges and potentials

The estimated incidence of sensorineural hearing impairment (>40 dB HL) at birth is 1.86 per 1000 newborns in developed countries and 30-40% of these are unilateral. Profound sensorineural unilateral hearing impairment or single sided deafness (SSD) can be treated with a cochlear implant. However, this treatment is costly and invasive and unnecessary in the eyes of many. Very young children with SSD often do not exhibit language and cognitive delays and it is hard to imagine that neurocognitive skills will present difficulties with one good ear. In the current paper we review the most recent evidence on the consequences of unilateral hearing impairment for auditory and neurocognitive factors. While data of both adults and children are discussed, we focus on developmental factors, congenital deafness and a window of opportunity for intervention. We discuss which etiologies qualify for a cochlear implant and present our multi-center prospective study on cochlear implants in infants with one deaf ear. The large, state-of-the art body of research allows for evidence-based decisions regarding management of unilateral hearing loss in children.

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.

Hearing Loss and Failed Newborn Hearing Screen

Hearing loss is the most common congenital defect. With early diagnosis and intervention, we are able to improve speech and language outcomes in this population. In this article, we discuss the implications of the newborn hearing screen, as well as diagnostic interventions, management, and intervention, and the increasing role of congenital cytomegalovirus screening.

Children with unilateral cochlear nerve canal stenosis have bilateral cochleovestibular anomalies

OBJECTIVES/HYPOTHESIS

To investigate the cochleovestibular apparatus bilaterally in children with isolated unilateral bony cochlear nerve canal (bCNC) stenosis.

STUDY DESIGN

Retrospective review.

METHODS

Imaging studies of children with unilateral bCNC stenosis (<1.0 mm) on computed tomography imaging (N = 36) were compared with controls imaged due to trauma without temporal bone injury (N = 32). Twenty-six measurements were obtained in each ear, assessing the bony internal auditory canal (IAC), cochlea, and vestibular end-organs, and were analyzed using one-way analysis of variance for intersubject comparisons and paired t tests for intrasubject comparisons with a Bonferroni adjustment for multiple comparisons (P = .0006).

RESULTS

Patients with bCNC stenosis had a smaller IAC (P < .000) and cochlea (P < .000) on the stenotic side as compared with controls. Although the vestibular end-organ was also smaller in bCNC ears, this difference was not significant. The contralateral ear also had a smaller bCNC (P < .000) and cochlea (P < .000) as compared with controls, although to a lesser degree than the stenotic side.

CONCLUSIONS

Children with unilateral bCNC stenosis have abnormal biometry of both the cochlea and the vestibular end-organ in the affected and the normal contralateral ear as compared with controls.

LEVEL OF EVIDENCE

3b Laryngoscope, 129:2403-2408, 2019.

Limiting asymmetric hearing improves benefits of bilateral hearing in children using cochlear implants

Neurodevelopmental changes occur with asymmetric hearing loss, limiting binaural/spatial hearing and putting children at risk for social and educational challenges. These deficits may be mitigated by providing bilateral hearing in children through auditory prostheses. Effects on speech perception and spatial hearing were measured in a large cohort of >450 children who were deaf and used bilateral cochlear implants or bimodal devices (one cochlear implant and a contralateral hearing aid). Results revealed an advantage of bilateral over unilateral device use but this advantage decreased as hearing in the two ears became increasingly asymmetric. Delayed implantation of an ear with severe to profound deafness allowed asymmetric hearing, creating aural preference for the better hearing ear. These findings indicate that bilateral input with the most appropriate device for each ear should be provided early and without delay during development.