Clinical outcomes following cochlear implantation in children with inner ear anomalies

Early cochlear implantation for children with single sided deafness

OBJECTIVES

Single-sided deafness (SSD) can have consequences for a child's language, educational, and social development. A cochlear implant (CI) is the only device which can restore true binaural hearing, yet they are only approved for children with (SSD) over the age of five in the United States. Reports on speech perception outcomes for children implanted at a younger age are limited. The present study aims to examine the effects of age at implantation, duration of deafness, hearing loss etiology, and presence of additional disabilities on device usage and speech perception outcomes.

METHODS

A retrospective chart review was used to examine demographics and speech perception outcomes for 18 children implanted at age five or younger.

RESULTS

Speech perception results were highly variable, with some children deriving significant benefit and others demonstrating no sound awareness through the implant alone. Age at implantation and duration of deafness did not have a clear impact on outcomes. Device usage was low in many children, often those with anatomical abnormalities such as a hypoplastic cochlear nerve. There are challenges to assessing speech perception in young children with SSD, leading to a lack of standardized outcome measures.

CONCLUSIONS

Early CI for children with SSD may improve speech perception, but benefit is not guaranteed. Candidacy evaluation should consider both medical and audiological factors, in addition to the degree of family support and realistic expectations. Caution is especially warranted in children with significant anatomical anomalies.

Effect of Cochlear Implant Electrode Insertion Depth on Speech Perception Outcomes: A Systematic Review

Objective

The suitable electrode array choice is broadly discussed in cochlear implantation surgery. Whether to use a shorter electrode length under the aim of structure preservation versus choosing a longer array to achieve a greater cochlear coverage is a matter of debate. The aim of this review is to identify the impact of the insertion depth of a cochlear implant (CI) electrode array on CI users' speech perception outcomes.

Databases Reviewed

PubMed was searched for English-language articles that were published in a peer-reviewed journal from 1997 to 2022.

Methods

A systematic electronic search of the literature was carried out using PubMed to find relevant literature on the impact of insertion depth on speech perception. The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines of reporting. Studies in both, children and adults with pre- or postlingual hearing loss, implanted with a CI were included in this study. Articles written in languages other than English, literature reviews, meta-analyses, animal studies, histopathological studies, or studies pertaining exclusively to imaging modalities without reporting correlations between insertion depth and speech outcomes were excluded. The risk of bias was determined using the "Risk of Bias in Nonrandomized Studies of Interventions" tool. Articles were extracted by 2 authors independently using predefined search terms. The titles and abstracts were screened manually to identify studies that potentially meet the inclusion criteria. The extracted information included: the study population, type of hearing loss, outcomes reported, devices used, speech perception outcomes, insertion depth (linear insertion depth and/or the angular insertion depth), and correlation between insertion depth and the speech perception outcomes.

Results

A total of 215 relevant studies were assessed for eligibility. Twenty-three studies met the inclusion criteria and were analyzed further. Seven studies found no significant correlation between insertion depth and speech perception outcomes. Fifteen found either a significant positive correlation or a positive effect between insertion depth and speech perception. Only 1 study found a significant negative correlation between insertion depth and speech perception outcomes.

Conclusion

Although most studies reported a positive effect of insertion depth on speech perception outcomes, one-third of the identified studies reported no correlation. Thus, the insertion depth must be considered as a contributing factor to speech perception rather than as a major decisive criterion.

Registration

This review has been registered in PROSPERO, the international prospective register of systematic reviews (CRD42021257547), available at https://www.crd.york.ac.uk/PROSPERO/.

Audiological and Speech Outcomes of Cochlear Implantation in Inner Ear Malformation Compared to the Normal Inner Ear

To compare the overall clinical outcomes of cochlear implantation in children with structural inner ear abnormalities, with results of implantation in children with radiologically 'normal' inner ears. To study the incidence and performance outcomes of cochlear implantation in children with inner ear malformations (IEMs). It is a retrospective case control study of 57 normal and 57 abnormal inner ear patients operated for cochlear implant between Jan 1, 2014 and Aug 1, 2017, by Veria technique. The age range was between 12 months and 15 years. The prevalence of IEMs was 13.8%. Of the 57 cases with IEMs, 33.3% were of enlarged vestibular acqueduct, 7% were of isolated Incomplete Partition type-2, 21.1% cases were of Mondini's dysplasia, 3.5% of Incomplete partition type-1 and 8.8% of cochlear nerve hypoplasia. Most commonly encountered malformation was EVA while IP-1 was the least common malformation. A CSF gusher was experienced in 11 cases. There was a statistically significant difference between the CAP and SIR scores of both IEM and control groups, both at 1 year and at 2 years (1 year CAP score p value < 0.001, 2 year CAP score p value 0.002 and 1 year SIR score, p value < 0.001, 2 year SIR score, p value 0.013). There was progressive improvement in the scores (of both groups) at the 2 year mark, compared to 1 year scores. Cochlear implantation is safe and surgically feasible in children with IEMs. However, the hearing outcome and speech perception outcomes are poor than those of patients with normal anatomy, with an exception seen in enlarged vestibular aqueduct.

Application of UNETR for automatic cochlear segmentation in temporal bone CTs

OBJECTIVE

To investigate the feasibility of a deep learning method based on a UNETR model for fully automatic segmentation of the cochlea in temporal bone CT images.

METHODS

The normal temporal bone CTs of 77 patients were used in 3D U-Net and UNETR model automatic cochlear segmentation. Tests were performed on two types of CT datasets and cochlear deformity datasets.

RESULTS

Through training the UNETR model, when batch_size=1, the Dice coefficient of the normal cochlear test set was 0.92, which was higher than that of the 3D U-Net model; on the GE 256 CT, SE-DS CT and Cochlear Deformity CT dataset tests, the Dice coefficients were 0.91, 0.93, 0 93, respectively.

CONCLUSION

According to the anatomical characteristics of the temporal bone, the use of the UNETR model can achieve fully automatic segmentation of the cochlea and obtain an accuracy close to manual segmentation. This method is feasible and has high accuracy.

Cochlear Implantation Outcomes in Pediatrics with Inner Ear Malformations in a Tertiary Care Hospital in Ahvaz

Cochlear implantation (CI) has been successful in individuals with sensorineural hearing loss (SNHL) over the last few years. This study assessed the auditory and speech performance results of pediatrics with inner ear malformations (IEMs) following cochlear implantation at the Ahvaz cochlear implantation center and compared the outcomes of various malformations. All pediatrics with IEMs undergoing CI were included in the study. This retrospective study was performed on pediatrics with congenital IEMs who underwent cochlear implantation in Ahvaz cochlear implantation center between 2014 and 2019. The Category of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scores are two of the most frequently administered tests. The CAP with ranging from 0 (displays no awareness of environmental sounds) to 7 (can use the telephone with a familiar talker), was used to measure the speech perception performance of the implanted children. Furthermore, SIR consists of five performance categories ranging from "prerecognizable words in spoken language" to "connected speech is intelligible to all listeners". Finally, the study included 22 patients. The evaluation of the CT-Scan revealed three types of inner ear malformation: Incomplete Partition (IP)-I in 2 (9.1%), IP-II in 12 (54.5%), and common cavity in 8 (36.4%) individuals. The results were shown that the median CAP score preoperative was 0.5 (interquartile range (IQR): 0-2) and postoperative was 3.5 (IQR: 3-7). There were statistically significant differences in CAP scores between preoperative and second-year follow-up postoperative (p value = 0.036). The results were shown that the median SIR score preoperative was 1 (IQR: 1-5) and postoperative was 2 (IQR: 1-5). There were statistically significant differences in SIR scores between preoperative and second-year follow-up postoperative (p value = 0.001). Following a thorough preoperative screening, patients with specific IEMs can be candidates for CI and not a contraindication. There were statistically significant differences in CAP and SIR scores between preoperative and second-year follow-up postoperative in the common cavity and IP-II groups.

Speech Perception and Sound Localization Skills in Inner Ear Malformations: Children With Incomplete Partition Type-II

OBJECTIVE

The present study aimed to evaluate binaural auditory skills in bimodal and bilateral pediatric cochlear implant (CI) users with incomplete partition type-II (IP-II) and to reveal the effect of IP-II on performance by comparing the results to pediatric CI users with normal cochlear morphology.

STUDY DESIGN

Cross-sectional study.

SETTING

Tertiary referral center.

METHODS

Forty-one CI users (mean age 8.8 ± 1.9) were grouped as bimodal (BIM-IP) and bilateral (BIL-IP) users with IP-II; bimodal (BIM-N) and bilateral (BIL-N) users with normal cochlear anatomy. Speech perception in noise and sound localization skills were compared under 2 conditions; binaural (bilateral or bimodal) and monaural (first CI alone).

RESULTS

BIM-IP and BIL-IP showed no performance difference in binaural tasks. The BIM-N group showed remarkably poor performance in comparison to the groups of BIL-IP (p = .007), BIM-IP (p < .001), and BIL-N (p = .004) in terms of speech-in-noise skills. In sound localization abilities, similar significant differences were found between the group of BIM-N and the groups of BIL-IP (p = .001), BIM-IP (p < .001), and BIL-N (p = .004). All groups showed statistically significant improvements in binaural condition on both tasks (p < .05).

CONCLUSION

We revealed that bilateral and bimodal pediatric CI users with IP-II benefitted from implantation as much as bilateral users with normal anatomy. Differences in residual hearing between groups may explain the poor performance of bimodal users with normal cochlear morphology. To the best of our knowledge, it is the first study to unveil binaural performance characteristics in children diagnosed with a specific inner ear malformation subgroup.

Impact of Sociodemographic Disparities on Language Outcomes After Cochlear Implantation in a Diverse Pediatric Cohort

OBJECTIVE

We examined how sociodemographic and audiologic factors affect receptive and expressive language outcomes in children with cochlear implantation.

STUDY DESIGN

Retrospective cohort study.

SETTING

A hearing loss (HL) clinic at a tertiary center.

METHODS

Sociodemographic variables, HL characteristics, age at implantation, and receptive language scores (Preschool Language Scale and the Clinical Evaluation of Language Fundamentals) were collected from patients with congenital HL who received their first implant by 4 years old after January 1, 2007. t Tests, linear regression, Mann-Whitney, Cohen's d, and mediation analysis were used for descriptive statistics and hypothesis testing.

RESULTS

Among 79 patients, 42 (53%) were females, 44 (56%) under-represented minorities, and 56 (71%) had public insurance. At least 1 year after implantation, the median receptive language score was 69 (range 50-117). Females (p = .005), having private insurance (p = .00001), having a Cochlear Implant Profile score below 4 (p = .0001), and receiving their implant at or before 12 months of age (p = .0009) were significantly associated with improved receptive language outcomes. Insurance type had a significant effect on receptive language outcomes, independent from age at first implantation (total effect: coef = -13.00, p = .02; direct effect: coef = -12.26, p = .03; indirect effect: coef = -0.75, p = .47). Sociodemographic variables had large effect sizes, with the Cochlear Implant Profile score having the largest effect size (d = 1.3).

CONCLUSION

Sociodemographic factors have a large impact on receptive language outcomes. Public insurance is associated with worse receptive language, not mediated by later age at implantation, suggesting that other factors primarily impact language outcomes in publicly insured children with cochlear implants.

Cochlear implantation in adults and pediatrics with enlarged vestibular aqueduct: a systematic review on the surgical findings and patients' performance

PURPOSE

Cochlear implantation (CI) has been considered a safe and effective management option for patients with severe to profound hearing loss. Patients with enlarged vestibular aqueduct (EVA) could be challenging with some variations in surgical approaches, intraoperative surgical notes, and clinical outcomes. This study aimed to  review the surgical and clinical outcomes of cochlear implantation among patients with EVA.

MATERIALS AND METHODS

A systematic literature search was carried out in five major databases. All original studies reporting cochlear implantation in patients with EVA were included for qualitative data synthesis. The risk of bias was independently assessed through the National Intuitional of Health tool. The review protocol was registered in PROSPERO (reference number: CRD42021225900).

RESULTS

A total of 34 studies with 4035 subjects were included. Of them, 853 (21.14%) had EVA and underwent CI. Mondini malformation was the most frequently associated anomaly (n = 78, 11.1%). Unilateral implantation was performed in 258 cases while bilateral in 119 subjects. Postoperative complications included CSF/perilymph gusher (n = 112), CSF oozing (n = 18), and partial electrode insertion (n = 6). Closing the cochleostomy with temporalis fascia, muscle, connective tissue, or fibrin glue was the most frequently reported approach to manage CSF/perilymph gusher (n = 67, 56.7%) while packing was performed in six patients.

CONCLUSION

Patients with EVA demonstrated audiometric and speech performance improvement after CI. However, many patients had intra- or postoperative complications. Further research is needed as the outcomes may be affected by associated temporal bone pathology, the timing of implant, and hearing condition.

Cochlear Implantation in Children with Enlarged Vestibular Aqueduct: A Systematic Review of Surgical Implications and Outcomes

OBJECTIVES

This study investigated age at implantation, improvement in hearing and speech perception outcomes, as well as surgical complications in pediatric cochlear implant recipients with Pendred Syndrome (PS) or non-syndromic enlarged vestibular aqueduct (NSEVA).

DESIGN

A systematic review of the literature between 1984 and 2021 was performed. Two independent reviewers performed abstract and full-text screening using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were: English language, cochlear implant, age at implantation available, age <18 years, PS, Mondini malformation, and enlarged vestibular aqueduct. Full-text analysis was completed using the National Institute of Health assessment tool for case series and case-control studies. Studies were also graded according to the Oxford Centre for Evidence-Based Medicine grading system.

RESULTS

In total, 198 studies were identified and screened, and 55 studies were included for analysis. Audiological outcomes were available in 46 studies, and the four-frequency pure-tone audiogram average improved by 60 to 78 dB HL due to cochlear implantation. Auditory performance and speech intelligibility scores increased by 44%. The overall average implantation age was 60 months. The implantation age was 21 months lower in the studies where individuals were implanted after the year 2000 compared with those implanted before the year 2000. Perilymph gusher/oozing was the most common surgical incident reported, occurring in 187 of 1572 implantations.

CONCLUSIONS

In children with PS/NSEVA, cochlear implantation improves pure-tone average by 60 to 78 dB HL and capacity of auditory performance/speech intelligibility by 44%. The implantation age for these children has decreased during the last two decades but is still somewhat higher than reported for unselected pediatric cochlear implantation. Perilymph gusher/oozing is the most common surgical complication.

Systematic review of cochlear implantation in patients with inner ear malformations

OBJECTIVES

To evaluate the outcomes of cochlear implantation in patients with severe to profound sensorineural hearing loss due to inner ear malformations (IEMs) when compared to patients without IEMs. We discussed audiological outcomes such as open-set testing, closed-set testing, CAP score, and SIR score as well as postoperative outcomes such as cerebrospinal fluid gusher and incomplete insertion rate associated with cochlear implantation in individuals with IEMs.

DATA SOURCES

PubMed, Science Direct, Web of Science, Scopus, and EMBASE databases.

REVIEW METHODS

After screening a total of 222 studies, twelve eligible original articles were included in the review to analyze the speech and hearing outcomes of implanted patients with IEMs. Five reviewers independently screened, selected, and extracted data. The "Tool to Assess Risk of Bias in Cohort Studies" published by the CLARITY group was used to perform quality assessment on eligible studies. Systematic review registration number: CRD42021237489.

RESULTS

IEMs are more likely to be associated with abnormal position of the facial nerve, raising the risk of intraoperative complications. These patients may benefit from cochlear implantation, but audiological outcomes may also be less favorable than in individuals without IEMs. Furthermore, due to the risk of cerebrospinal fluid gusher, incomplete insertion of electrodes, and postoperative facial nerve stimulation, surgeons can employ precautionary measures such as preoperative imaging and proper counseling. Postoperative imaging is suggested to be beneficial in ensuring proper electrode placement.

CONCLUSIONS

Cochlear implants (CIs) have the potential to provide auditory rehabilitation to individuals with IEMs. Precise classification of the malformation, preoperative imaging and anatomical mapping, appropriate electrode selection, intra-operative techniques, and postoperative imaging are recommended in this population.

Internal auditory canal volume in normal and malformed inner ears

Purpose

A narrow bony internal auditory canal (IAC) may be associated with a hypoplastic cochlear nerve and poorer hearing performances after cochlear implantation. However, definitions for a narrow IAC vary widely and commonly, qualitative grading or two-dimensional measures are used to characterize a narrow IAC. We aimed to refine the definition of a narrow IAC by determining IAC volume in both control patients and patients with inner ear malformations (IEMs).

Methods

In this multicentric study, we included high-resolution CT (HRCT) scans of 128 temporal bones (85 with IEMs: cochlear aplasia, n = 11; common cavity, n = 2; cochlear hypoplasia type, n = 19; incomplete partition type I/III, n = 8/8; Mondini malformation, n = 16; enlarged vestibular aqueduct syndrome, n = 19; 45 controls). The IAC diameter was measured in the axial plane and the IAC volume was measured by semi-automatic segmentation and three-dimensional reconstruction.

Results

In controls, the mean IAC diameter was 5.5 mm (SD 1.1 mm) and the mean IAC volume was 175.3 mm3 (SD 52.6 mm3). Statistically significant differences in IAC volumes were found in cochlear aplasia (68.3 mm3, p < 0.0001), IPI (107.4 mm3, p = 0.04), and IPIII (277.5 mm3, p = 0.0004 mm3). Inter-rater reliability was higher in IAC volume than in IAC diameter (intraclass correlation coefficient 0.92 vs. 0.77).

Conclusions

Volumetric measurement of IAC in cases of IEMs reduces measurement variability and may add to classifying IEMs. Since a hypoplastic IAC can be associated with a hypoplastic cochlear nerve and sensorineural hearing loss, radiologic assessment of the IAC is crucial in patients with severe sensorineural hearing loss undergoing cochlear implantation.

Hearing-related quality of life assessment of pediatric cochlear implant users with inner ear malformations

OBJECTIVES

To assess the quality of life (QoL) in child and adolescent cochlear implant users with inner ear malformations (IEM) and to compare their outcomes to their cochlear implant using peers with normal inner ear structures.

METHODS

The present sample consisted of 100 children (45 with IEM, 55 without IEM) and 100 adolescents (46 with IEM, 54 without IEM). The following QoL questionnaires were used to assess the hearing-related QoL: The Hearing Environments and Reflection on Quality of Life 26 (HEAR-QL-26 for children between 7 and 12 years of age) and HEAR-QL-28 (for adolescents between 13 and 18 years of age). Both questionnaires were based on a 5-points Likert scale from 0 to 4, with higher scores indicating a better perception of QoL. The scores were converted to percentage values (never = 100, almost never = 75, sometimes = 50, often = 25, almost always = 0).

RESULTS

For the patients with IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 50.4 (SD = 18.9) and 54.5 (SD = 19.6), respectively. For the patients without IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 72.7 (SD = 18.0) and 65.0 (SD = 19.1), respectively. For both child and adolescent subgroups, statistically significant differences were observed between QoL scores from patients with and without IEM (p < 0.001). There were no statistically significant effects of the malformation type on the QoL findings (p ≥ 0.05).

CONCLUSION

Child and adolescent cochlear implant users with IEM had significantly lower scores on validated HEAR-QL versions in comparison to their implanted peers without IEM.

Pediatric cochlear implant fitting parameters in inner ear malformation: Is it same with normal cochlea?

OBJECTIVES

The aim was to evaluate the cochlear implant (CI) mapping parameters of CI users with inner ear malformation (IEM) and to reveal the changes in parameters over time.

METHODS

In total, 118 CI users were included with 127 ears (68-IEM; 59-normal cochlear anatomy) in present retrospective study. The impedance measurements, thresholds levels-THR, most comfortable levels- MCL, pulse width-PW and rate values were analyzed in both IEM and control group at the initial activation, 6th,12th and 24th months postoperatively.

RESULTS

There were statistically significant differences in impedance measurements in several time points. And also, there was a remarkable difference in THR & MCL and PW values between IEM and control groups in all time points (p < 0.05). THR & MCL levels and PW values increased significantly between all time periods in both groups (p < 0,008) and values of parameters in IEM-group were higher than those of control group. When comparing rates, statistically significant difference was observed only at the initial activation in both within (p < 0.001) and between groups (p = 0.03).

CONCLUSION

Pediatric CI users with IEM need individual changes in fitting parameters. More frequent map sessions should be planned as they require more PW, THR and MCL increase over time. The increase rate differs between IEM subgroups depending on the deviation of malformation from the normal cochlear anatomy. This study is the first to in its attempt to reveal the mapping characteristics and long-term changes in pediatric CI users with different IEM subgroups.

Electrically evoked auditory brainstem responses in deaf patients with Mondini malformation during cochlear implantation

PURPOSE

To investigate the auditory pathway functions in deaf patients with Mondini malformation using the electrically evoked auditory brainstem response (EABR) during cochlear implantation (CI).

METHODS

A total of 58 patients with severe to profound sensorineural hearing loss (SNHL) were included in this study. Of these patients, 27 cases had Mondini malformation and 31 control cases had no inner ear malformations (IEMs). Intraoperative EABRs evoked by electrical stimulation at the round window niche (RWN) and round window membrane (RWM) were recorded.

RESULTS

Patients with Mondini malformation showed significantly lower EABR extraction rates than those with no IEMs did. However, for patients who showed EABRs, no significant difference in EABR thresholds, wave III (eIII) latencies, wave V (eV) latencies or eIII-eV latency intervals was found between two groups.

CONCLUSION

The physiological functions of the peripheral auditory system in patients with Mondini malformation may divide into opposite extremes, as revealed by a robust EABR and the absence of the EABR, respectively. The auditory conduction function should be objectively and individually evaluated for patients with Mondini malformation by the EABR.

Comprehensive medical evaluation of pediatric bilateral sensorineural hearing loss

Children with bilateral sensorineural hearing loss (SNHL) should undergo a comprehensive medical evaluation to determine the underlying etiology and help guide treatment and counseling. In this article, we review the indications and rationale for medical evaluation of pediatric bilateral SNHL, including history and physical examination, imaging, genetic testing, specialist referrals, cytomegalovirus (CMV) testing, and other laboratory tests. Workup begins with a history and physical examination, which can provide clues to the etiology of SNHL, particularly with syndromic causes. If SNHL is diagnosed within the first 3 weeks of life, CMV testing should be performed to identify patients that may benefit from antiviral treatment. If SNHL is diagnosed after 3 weeks, testing can be done using dried blood spots samples, if testing capability is available. Genetic testing is oftentimes successful in identifying causes of hearing loss as a result of recent technological advances in testing and an ever-increasing number of identified genes and genetic mutations. Therefore, where available, genetic testing should be performed, ideally with next generation sequencing techniques. Ophthalmological evaluation must be done on all children with SNHL. Imaging (high-resolution computed tomography and/or magnetic resonance imaging) should be performed to assess for anatomic causes of hearing loss and to determine candidacy for cochlear implantation when indicated. Laboratory testing is indicated for certain etiologies, but should not be ordered indiscriminately since the yield overall is low.

New SMS Classification of Cochleovestibular Anomalies: Our Experience with 25 Cases of Type I Anomaly

PURPOSE

To study and analyse the radiological and surgical findings of 25 cochlear implantees with SMS type-I cochleovestibular malformation and to compare their outcomes in terms of hearing and speech gains pre- and post-operatively.

METHODS

Retrospective analysis of cochlear implanted candidates over a period of 8 year from 3 institutions was undertaken and 25 patients suffering from pre-lingual profound congenital sensori-neural hearing loss along with presence of SMS type I cochleovestibular malformation were studied. Pre-operative radiology, surgical difficulties and complication, and post-operative hearing and speech outcomes upto a period of 2 years, using IT-MAIS scores were noted. Statistical comparison pre- and post-implantation was done using Wilcoxon signed rank test and a p-value of < 0.05 was considered significant.

RESULTS

In 25 cases, we encountered 2 posterior SCC dysplasia, 15 enlarged vestibular aqueducts (LVA), 2 dilated vestibules, 4 superior SCC dysplasia, 2 cases with both posterior and superior SCC dysplasia and of those 1 had a dilated vestibule also. Intra-operatively, CSF leak was observed in 10 patients. Complete electrode insertion and good electrical response (NRT) was detected in all. No facial nerve anomaly was encountered. IT-MAIS scores increased from a pre-operative mean of 4.32 to 34.56 two years post-operatively and this difference was found to be statistically significant.

CONCLUSION

Our experience with SMS Type I malformations show promising and motivating results with less chances of complications, similar to implant candidates with normal anatomy. The outcomes in this group of patients are definitely not affected by any malformations in semicircular canals, vestibule or vestibular aqueduct.

Cochlear Implantation in Pediatric Patients With Enlarged Vestibular Aqueduct: A Systematic Review

OBJECTIVE(S)

To describe cochlear implantation (CI) outcomes, with speech perception, auditory, language, and parent-reported auditory and speech behaviors, in children with an enlarged vestibular aqueduct (EVA) and incomplete partition type 2 (IP-II) and compare to control children without inner ear malformations (IEMs) and to determine cerebrospinal fluid gusher rates and effect on outcomes.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, Embase, Cochrane, and CINAHL databases were searched from inception to February 2020. Studies reporting relevant outcomes in children with EVA or EVA + IP-II and controls without IEMs undergoing CI were included. Mean differences in speech perception, auditory, and language scores between cases and controls were meta-analyzed. Gusher rates were determined by proportion meta-analyses.

RESULTS

Of 214 identified articles, 42 met inclusion criteria, evaluating 775 cases and 2,191 controls. Of -cases, 578 (74.6%) had EVA and 197 (25.4%) had EVA + IP-II. Cases showed a significant improvement in speech perception, auditory and language performance, comparable to controls. Parent-reported auditory and speech production behaviors outcomes were positive among cases and comparable to controls. Pooled gusher proportions in EVA and EVA + IP-II cases were 27.7% (95% CI: 17.6-39.1) and 48.6% (95% CI: 28.6-69.0), respectively, with a proportion difference of 20.9% (95% CI: 11.0-30.1). Gusher occurrence did not impact speech perception or language outcomes.

CONCLUSION

Outcomes in children with EVA or EVA + IP-II undergoing CI are favorable and largely comparable to outcomes in children with hearing loss undergoing CI without IEMs. Intraoperative gusher is more prevalent among children with EVA + IP-II as compared to iEVA. Gusher does not influence speech perception and language development outcomes.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

Correlation of cochlear aperture stenosis with cochlear nerve deficiency in congenital unilateral hearing loss and prognostic relevance for cochlear implantation

The use of neonatal hearing screening has enabled the identification of congenital unilateral sensorineural hearing loss (USNHL) immediately after birth, and today there are several intervention options available to minimize potential adverse effects of this disease, including cochlear implantation. This study aims to analyze the characteristics of the inner ear of a homogeneous group of congenital non-syndromic USNHL to highlight the features of the inner ear, which can help in clinical, surgical, and rehabilitative decision-making. A retrospective chart review was carried out at a tertiary referral center. Systematic diagnostic work-up and rigorous inclusion-exclusion criteria were applied to 126 children with unilateral hearing impairment, leading to a selection of 39 strictly congenital and non-syndromic USNHL cases, undergoing computed tomography (CT) and magnetic resonance (MR) imaging studies. The frequency and type of malformations of the inner ear in USNHL and unaffected contralateral ears were assessed, with an in-depth analysis of the deficiency of the cochlear nerve (CND), the internal auditory canal (IAC) and the cochlear aperture (CA). Inner ear anomalies were found in 18 out of 39 (46%) of the USNHL patients. In 1 subject, the anomalies were bilateral, and the CND resulted in the predominant identified defect (78% of our abnormal case series), frequently associated with CA stenosis. Only 3 out of 14 children with CND presented stenosis of the IAC. CND and CA stenosis (and to a much lesser extent IAC stenosis) are a frequent association within congenital and non-syndromic USNHL that could represent a distinct pathological entity affecting otherwise healthy infants. In the context of a diagnostic work-up, the evaluation with CT and MRI measurements should take place in a shared decision-making setting with thorough counseling. Both imaging techniques have proven useful in differentiating the cases that will most likely benefit from the cochlear implant, from those with potentially poor implant performance.

Evolving Criteria for Adult and Pediatric Cochlear Implantation

The indications for cochlear implantation have gradually expanded as advancements in technology have evolved, resulting in improved audiologic outcomes for both adult and children. There remains a significant underutilization of cochlear implant technology in the United States, and recognition of the potential benefits of cochlear implantation for non-traditional indications is critical for encouraging the evolution of candidacy criteria. Adult cochlear implantation candidacy has progressed from patients with bilateral profound sensorineural hearing loss (SNHL) to include patients with greater degrees of residual hearing, single-sided deafness and asymmetric hearing, and atypical etiologies of hearing loss (eg, vestibular schwannoma, Ménière's disease, and otosclerosis). Indications for pediatric cochlear implantation have similarly evolved from children with bilateral severe to profound SNHL to implanting children at a younger age, including those with residual hearing, asymmetric hearing loss, inner ear malformations, as well as cochlear nerve deficiency. In this editorial, the literature investigating cochlear implantation for nontraditional indications is reviewed with an aim to use the best available evidence to encourage the evolution of candidacy criteria.

Audiological Performance in Children with Inner Ear Malformations Before and After Cochlear Implantation: A Cohort Study of 274 Patients

BACKGROUND AND OBJECTIVE

Inner ear malformations (IEMs) are common in children with hearing loss. The different types of IEMs form a unique subgroup of cochlear implant (CI) candidates. We aimed to evaluate the auditory perception outcomes of CI in children with different types of IEMs and compare them with CI users without IEMs.

METHODS

The study included 274 CI users with and without IEMs as two groups (n = 137, each). Both groups' chronological age at implantation and duration of CI usage was matched (± 8 months). All subjects were evaluated pre-operatively and post-operatively by the Ling's sound test and the auditory perception test battery, which includes the Meaningful Auditory Integration Scale (MAIS), closed-set Pattern Perception Test (PPT) and open-set Sentence Recognition Test (SRT). Besides, children with IEMs were assessed for language development.

RESULTS

Progress in the IEMs' group differed according to the type of ear anomaly. CI users with enlarged vestibular aqueduct had the highest scores, while users with common cavity had the lowest. Children with IEMs performed well on the closed-set test while having difficulty with the open-set test.

CONCLUSION

Cochlear implantation outcomes are favourable in IEMs' patients with a cochlear nerve visible on magnetic resonance imaging. Our results indicate that it is critical to take the anatomical differences into account during follow-up and rehabilitation programmes. Each CI user should be evaluated according to his or her individual needs.

Evaluation of Subtotal Petrosectomy Technique in Difficult Cases of Cochlear Implantation

OBJECTIVES

To assess the validity of the subtotal petrosectomy (STP) technique in problematic cases of cochlear implant (CI) surgery, and review indications, outcomes, and related controversies.

STUDY DESIGN

This is a retrospective review of data from a private quaternary referral center of otology and skull base surgery.

PATIENTS AND METHODS

A review of patients who underwent CI with STP (STP-CI) as the leading approach was performed. Demographics, indications, surgical details, and main outcomes were evaluated. The surgeries performed were usually single-stage procedures encompassing a comprehensive mastoidectomy, blind sac closure of the external auditory canal (EAC), and mastoid obliteration with autologous fat.

RESULTS

A total of 107 cases were included. Mean follow-up was 7.1 years (range 1-13 years). The most frequent indication for STP-CI was chronic otitis media with/without cholesteatoma (32.7%), followed by open mastoid cavity (26.1%), and cochlear ossification (17.7%). Other difficult conditions where STP facilitates successful implantation include inner-ear malformations, temporal-bone trauma, unfavorable anatomic conditions, and revision surgery. A planned staged procedure was performed in 3 cases. The rate of major complications was 5.6% (n = 6). Three patients developed postauricular wound dehiscence which eventually resulted in device extrusion. No cases of recurrent/entrapped cholesteatoma, EAC breakdown, or meningitis were encountered. This is the largest single-center series of STP-CI reported in the literature.

CONCLUSIONS

When CI is intended in technically challenging cases or associated with a high risk of complications, STP is effective and reliable. Safe implantation and excellent long-term outcomes can be achieved provided surgical steps are properly followed. Single-stage procedures can be performed in most cases, even when there is active middle-ear disease.

Impact of cochlear abnormalities on hearing outcomes for children with cochlear implants

OBJECTIVE

Evaluate the impact of cochlear anomalies on hearing outcomes for pediatric patients with cochlear implants.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Charts were retrospectively reviewed for cases where pediatric cochlear implant surgery was performed between 2002 and 2018 at a single, tertiary care institution. Patients were divided into groups based on the presence or absence of radiological cochlear abnormalities, which were further classified as low or high risk anomalies. Hearing outcomes were evaluated by measuring pure tone averages and word recognition scores preoperatively, 3 and 12 months postoperatively, in addition to the most recent test results.

RESULTS

There were 154 ears implanted in our cohort of 100 patients. 107 ears had normal cochlear anatomy, 31 had low risk, and 16 had high risk abnormalities. The most common modality of preoperative imaging was CT scan. Postoperative mean pure tone average (PTA) was significantly higher in patients with inner ear anomalies compared to those with normal anatomy. No significant difference in PTA was noted between low versus high risk patients. <50% of patients had word recognition scores available within the first year following surgery.

CONCLUSION

Abnormalities of the inner ear significantly influenced hearing outcomes over time following cochlear implant surgery when compared to pediatric patients with normal anatomy. Obtaining hearing testing can be difficult in very young children and therefore future studies are warranted to further investigate the impact that cochlear abnormalities may have on hearing outcomes following cochlear implant surgery.

Diagnostic Value of 3D Segmentation in Understanding the Anatomy of Human Inner Ear Including Malformation Types

OBJECTIVE

To understand the anatomical and dimensional variations of the human inner ear using 3-dimensional (3D) segmentation within the Middle East population.

DESIGN

Retrospective study.

SETTING

King Abdullah Ear Specialist Center (KAESC) Riyadh, Saudi Arabia.

PARTICIPANT

Forty computed tomography (CT) images of patients with sensorineural hearing loss who underwent cochlear implant (CI) were taken for analysis.

MAIN OUTCOME MEASURES

Three-dimensional images showing the anatomical variations of the inner ear including various pathological conditions, cochlear parameters including basal turn diameter ("A" value), "B" value which is perpendicular to "A" value, cochlear height, length, and width of the internal auditory canal (IAC), intercochlear spacing, and electrode angular insertion depth (AID).

RESULTS

Out of 40 CT image data sets, 12 had normal inner-ear anatomy (NA), 4 with enlarged vestibular aqueduct syndrome (EVAS), 8 with only 2 turns of the cochlea (2TL), 7 with incomplete partition (IP) type II, 5 with cochlear hypoplasia, 1 with common cavity, and 3 with abnormal IAC. Taking the NA, EVAS, 2TL, and the IP type II cases altogether, age of the patient had no correlation with the "A" value; however, the "A" value had a linear correlation with the "B" value. The age of the patient had an increasing logarithmic correlation with the IAC length and the intercochlear spacing. The "A" value did not have any meaningful correlation with the cochlear height. Three data sets showed asymmetric inner-ear malformation types on either side of the ears. All these 40 cases were implanted with various CI electrode array variants and the corresponding postoperative plain film X-ray images showing the electrode AID are given separately in figures.

CONCLUSIONS

Three-dimensional segmentation of the inner ear from the temporal bone CT is a valuable clinical and training tool for surgeons and radiologists especially in difficult cases which will certainly help to understand the overall anatomical and dimensional variations.

Role of Targeted Next Generation Sequencing in the Etiological Work-Up of Congenitally Deaf Children

OBJECTIVES

The purpose of this study is to report the results of a comprehensive etiological work-up for congenitally deaf children including targeted next generation sequencing.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Fifty children with congenital, bilateral profound hearing loss (HL) (>90 dBnHL).

INTERVENTIONS

Etiological work-up included testing for pathogenic variants in GJB2, a phenotype driven genetic analysis, screening for congenital infections and imaging. When no etiology could be found, comprehensive genetic testing was performed using a HL gene panel including 45 syndromic and 96 non-syndromic HL genes.

RESULTS

Eleven patients carried bi-allelic pathogenic variants in GJB2. Phenotype driven genetic analysis identified two homozygous KCNQ1 patients (Jervell and Lange Nielsen syndrome) and one heterozygous CHD7 patient (CHARGE syndrome). One patient was diagnosed with achondroplasia and one had a clinical diagnosis of Waardenburg syndrome. A deafness gene panel evaluated 16 patients. In 12 out of 16, we identified a pathogenic (n = 12) or likely pathogenic (n = 2) variant and one variant of unknown significance (VUS). A definite diagnosis of non-syndromic or syndromic HL was made in 18 and seven patients, respectively. Non-genetic causes were congenital cytomegalovirus infection (n = 11), anatomic abnormalities (n = 2), neurological/metabolic/polymalformative conditions (n = 3), meningitis (n = 1), and auditory neuropathy (n = 1).

CONCLUSIONS

A definite genetic cause was found in 25 (50%) of congenital, bilaterally deaf children. Our data show that implementation of a gene panel improves the diagnostic yield for etiological work-up of congenital profound HL to 86%. Identification of the etiology of congenital HL may contribute to predicting outcomes of cochlear implantation.

Hearing Restoration in Cochlear Nerve Deficiency: the Choice Between Cochlear Implant or Auditory Brainstem Implant, a Meta-analysis

OBJECTIVE

To answer the dilemma clinician's face when deciding between cochlear implant (CI) and auditory brainstem implant (ABI) treatment options in patients with cochlear nerve deficiency (CND).

STUDY DESIGN

Case study supplemented with literature review and meta-analysis.

SETTING

Tertiary referral center.

PATIENT(S)

Child with CHARGE syndrome and congenital deafness.

INTERVENTION(S)

ABI as there was no benefit after bilateral cochlear implantation.

MAIN OUTCOME MEASURES

Speech and language development, quality of life.

RESULTS

In one ear the cochleovestibular nerve was present on magnetic resonance imaging (MRI) without preoperative ABR responses. In the contra lateral ear the nerve could not be identified, despite present ABR responses. Nevertheless, there was no positive outcome with CI. The patient had improved speech and language and quality of life with ABI. Of the 108 patients with CND and CI identified in the literature review, 25% attained open-set speech perception, 34% attained closed-set speech perception, and 41% detected sounds or less. The appearance of the cochlear nerve on MRI was a useful predictor of success, with cochlear nerve aplasia on MRI associated with a smaller chance of a positive outcome post cochlear implantation compared with patients with cochlear nerve hypoplasia.

CONCLUSION

Although patients with (apparent) cochlear nerve aplasia are less likely to benefit from CI, CI before ABI is supported as some patients attain closed or open-set levels of speech perception after cochlear implantation.

Application of multiplanar reconstruction of spiral CT in the diagnosis and treatment of enlarged vestibular aqueducts

Background: Multiplanar reconstruction (MPR) of High Resolution Computed Tomography (HRCT) makes it possible to achieve a clear view of inner ear structures. However, no agreement was reached on the standard measurement of inner ear. Objectives: To establish standard inner ear measurements for building criteria for cochlear structure evaluation. Material and Methods: HRCT scanning of the temporal bones of 82 cases with normal inner ear structures and 104 cases with an EVA and bilaterally sensorineural hearing loss (SNHL) was performed. Three standard cochlear plane and one vestibular plane were reconstructed by MPR. Results: Normative data of inner ear was measured and formulated. The most common malformation found in cases with EVA was incomplete partition type II (IP-II; 90.4%). The IP-II group had significantly greater modiolar height, cochlear aperture width, vestibular area, and vestibule width than did the control group. Different degrees of IP-II modiolar defects were observed using MPR. Conclusions and Significance: Standard cochlear plane can help us to evaluate the cochlear structure. The MPR standard measurement of inner ear is clinically valuable for the diagnosis and cochlear implant of EVA.

Outcome of Cochlear Implantation in Children With Narrow Bony Cochlear Nerve Canal

OBJECTIVE

To investigate the diameter of the bony cochlear nerve canal (BCNC) as a prognostic indicator of cochlear implantation (CI) in children.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Two hundred ninety two prelingual deaf children (323 ears) who received CI before the age of 5 years.

INTERVENTIONS

CI in pediatric patients.

MAIN OUTCOME AND MEASURES

Postoperative auditory performance was analyzed according to the diameter of the BCNC using the Mann-Whitney U test. Using the images of temporal bone computed tomography, patients were grouped according to the diameter of the BCNC: narrow (<1.4 mm, Group 1), normal (Group 2), and other anomalies (Group 3).

RESULTS

Group 1 (10.5%) showed a less significant degree of improvement in category of audiological performance (CAP) score than Groups 2 (57.3%) and 3 (32.2%). Scores obtained from both the open-set monosyllabic words and sentence tests were lower in Group 1 than Groups 2 and 3. Of the patients with narrow BCNC, the CAP score of patient with complete stenosis of BCNC (<0.2 mm) was lower than that of patients with BCNC between 0.2 and 0.8 mm, also 0.8 and 1.4 mm.

CONCLUSIONS

The improvement in auditory performance was limited in children with narrow BCNC and the narrower the BCNC, the more severe the limitation. However, gradual improvement can be expected and even children with narrow BCNC may be candidates for early CI and rehabilitation.

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.

Speech development in young children with Mondini dysplasia who had undergone cochlear implantation

OBJECTIVE

The purpose of this study was to investigate the development of speech skills in young children with Mondini dysplasia and age-matched deaf children with radiologically normal inner ears over a period of 5 years after cochlear implantation (CI).

METHODS

In total, 700 congenitally severely to profoundly deaf children (281 girls and 419 boys) participated in this study. All of the participants had undergone unilateral CI surgery before 36 months of age. The participants were categorized into two groups based on the absence or presence of Mondini dysplasia in the implanted ear, as assessed via high-resolution, thin-slice computerized tomography or magnetic resonance imaging: group A comprised 592 children with radiologically normal inner ears and group B comprised 108 children with Mondini dysplasia. The Meaningful Use of Speech Scale (MUSS) and Speech Intelligibility Rating (SIR) were used to evaluate the speech performance of all young children at various time points: pre-surgery and at 1, 3, 6, 12, 24, 36, 48, and 60 months after switch-on programming.

RESULTS

The mean scores of SIR and MUSS in children from both group A and group B showed significant improvements over time. No significant differences were found in the mean scores of SIR between the two groups at any time interval during the 5-year follow-up. The mean score of MUSS was significantly different between group A and group B at 12, 24, and 36 months after implantation, whereas no obvious differences were noted pre-surgery, and at 1, 3, 6, 48, and 60 months post-operation.

CONCLUSIONS

Young children with Mondini dysplasia develop their speech skills at a fast rate and achieve similar speech acquisition compared to age-matched children with radiologically normal inner ears 5 years post-operation. Therefore, CI is an effective intervention method for young children with Mondini dysplasia.

Spatial and temporal inhibition of FGFR2b ligands reveals continuous requirements and novel targets in mouse inner ear morphogenesis

Morphogenesis of the inner ear epithelium requires coordinated deployment of several signaling pathways, and disruptions cause abnormalities of hearing and/or balance. The FGFR2b ligands FGF3 and FGF10 are expressed throughout otic development and are required individually for normal morphogenesis, but their prior and redundant roles in otic placode induction complicates investigation of subsequent combinatorial functions in morphogenesis. To interrogate these roles and identify new effectors of FGF3 and FGF10 signaling at the earliest stages of otic morphogenesis, we used conditional gene ablation after otic placode induction, and temporal inhibition of signaling with a secreted, dominant-negative FGFR2b ectodomain. We show that both ligands are required continuously after otocyst formation for maintenance of otic neuroblasts and for patterning and proliferation of the epithelium, leading to normal morphogenesis of both the cochlear and vestibular domains. Furthermore, the first genome-wide identification of proximal targets of FGFR2b signaling in the early otocyst reveals novel candidate genes for inner ear development and function.

Morphology and cochlear implantation in enlarged vestibular aqueduct

PURPOSE

The purpose of this work is to explore audiometry following cochlear implantation (CI) in patients with enlarged vestibular aqueduct (EVA) and to investigate the effects of inner ear morphological variation on post CI audiometry.

METHODS

This was a retrospective review of both natural and cochlear-implant-aided audiometry results, using all available measurements in a mixed-effects model accounting for longitudinal change and the grouping structure of ears. Patients who visited our tertiary academic medical center between 2000 and 2016 were identified as having EVA according to Cincinnati criteria on radiological examination; patients eligible for CI were then selected for analysis.

RESULTS

Multivariable modeling showed a statistically significant hearing improvement in ears with EVA undergoing CI with regards to pure tone average (-64.0 dB, p < 0.0001), speech reception threshold (-57.90 dB, p < 0.0001), and word score (34.8%, p > 0.0001). Vestibular aqueduct midpoint size and the presence of incomplete partition type II (IP II) did not have significant independent associations with audiometric findings. However, multivariable modeling revealed a statistically significant interaction between IP II and CI such that IP II ears demonstrated a decrease in WS improvement of 30.2% (p = 0.0059) compared to non-IP II ears receiving CI.

CONCLUSION

There is a statistically significant audiometric benefit to ears with EVA receiving CI. Morphology, specifically the presence of IP II, may hinder CI benefit in terms of word score however this finding needs clinical validation. This data improves personalization of surgical counseling and planning for patients with EVA considering CI.

Rare case of bilateral aural atresia and cochlear dysplasia: when cochlear implantation is not the answer

OBJECTIVE AND IMPORTANCE

Reports of patients with concurrent middle and inner ear anomalies are rare. These patients present a surgical challenge for cochlear implantation. The surgical risk must be weighed against the predicted benefit of the patient's hearing outcome and subsequent development of speech and language as well as their quality of life.

CLINICAL PRESENTATION

Thirteen-year-old boy presented to the Otology clinic for auditory rehabilitation options. He has mild developmental delay, is non-verbal and communicates via American Sign Language. He was born with bilateral aural atresia and never wore amplification. On exam he has grade 1 microtia and complete ear canal atresia bilaterally. His behavioural hearing test shows profound sensorineural hearing loss of both ears. The computed tomography scan shows bilateral underdeveloped and completely opacified mastoid and middle ear, complete bony atresia of the ear canals, and an under-partitioned cochlea with poorly defined modiolus, among other abnormalities. The patient and his family were counselled on the available options as well as the need for any further studies.

INTERVENTION

Counselling of patient and family.

CONCLUSION

While there have been reports in the literature of performing cochlear implantations in patients with a concurrent atresia and cochlear dysplasia, these were patients whose degree of inner ear anomalies was relatively minor and their prognosis of a good audiological outcome was favourable. The presented case is that of a patient for whom the surgical approach to the cochlea alone would be difficult. More importantly, his quality of life would not significantly improve in light of the predicted limited hearing and language development outcomes, given the severity of his inner ear abnormalities, limited communication abilities, prolonged period of deafness and developmental delays.