Evolution of communication abilities after cochlear implantation in prelingually deaf children

Advances in Evaluation of Electrode Insertion Trauma Induced Residual Hearing loss in Cochlear Implant Recipients and its significance- A Narrative Review

Cochlear implant surgery has revolutionized the management of profound hearing loss, with a growing focus on preserving residual hearing, particularly low-frequency hearing. This review synthesizes existing literature on cochlear implantation techniques, surgical principles, and emerging therapies aimed at reducing post-implantation hearing loss. Methodologically, a comprehensive narrative literature review was conducted, encompassing various study designs and participant demographics. The search strategy involved major biomedical databases, focusing on articles in English. Surgical techniques such as "soft surgery" emphasize minimizing mechanical stress on the cochlea, while advancements in pharmacological agents explore the use of corticosteroids, neurotrophins, and growth factors to enhance hearing preservation. Electrode design and insertion strategies are evolving to minimize trauma and optimize hearing outcomes, including consideration of insertion forces and electrode array designs. Evaluating residual hearing loss involves sophisticated techniques like electrocochleography and radiological imaging. The impact of residual hearing on auditory verbal outcomes is variable, with studies indicating positive correlations with language development, particularly in speech production. Emerging strategies in electrode design, surgical techniques, and drug delivery hold promise for improving outcomes in cochlear implantation. However, challenges such as the lack of standardized guidelines and the need for further clinical trials remain. Future directions include the exploration of nanotechnologies, gene therapies, and stem cells for constructing bionic ears, although ethical and technical hurdles persist. This review underscores the ongoing efforts to enhance cochlear implant functionality and the need for continued research to optimize outcomes for patients with hearing loss.

Measuring speech intelligibility with deaf and hard-of-hearing children: A systematic review

There is great variability in the ways in which the speech intelligibility of d/Deaf and hard-of-hearing (DHH) children who use spoken language as part, or all, of their communication system is measured. This systematic review examined the measures and methods that have been used when examining the speech intelligibility of children who are DHH and the characteristics of these measures and methods. A systematic database search was conducted of CENTRAL; CINAHL; Cochrane; ERIC; Joanna Briggs; Linguistics, Language and Behavior Abstracts; Medline; Scopus; and Web of Science databases, as well as supplemental searches. A total of 204 included studies reported the use of many different measures/methods which measured segmental aspects of speech, with the most common being Allen et al.'s (2001, The reliability of a rating scale for measuring speech intelligibility following pediatric cochlear implantation. Otology and Neurotology, 22(5), 631-633. https://doi.org/10.1097/00129492-200109000-00012) Speech Intelligibility Rating scale. Many studies included insufficient details to determine the measure that was used. Future research should utilize methods/measures with known psychometric validity, provide clear descriptions of the methods/measures used, and consider using more than one measure to account for limitations inherent in different methods of measuring the speech intelligibility of children who are DHH, and consider and discuss the rationale for the measure/method chosen.

Sociodemographic disparities in pediatric cochlear implantation outcomes: A systematic review

OBJECTIVES

To determine the impact of sociodemographic factors on post-operative performance outcomes among PCI recipients across the world.

METHODS

A qualitative systematic review of PubMed, Scopus, Web of Science, and Embase was undertaken for studies analyzing the association of sociodemographic factors with measures of PCI outcomes published before July 18, 2021. Study quality assessment tools from the National Institutes of Health (NIH) were used to assess for risk of bias.

RESULTS

Out of 887 unique abstracts initially retrieved, 45 papers were included in the final qualitative systematic review. Sociodemographic disparities in PCI outcomes from 4702 PCI recipients were studied in 19 countries, with 14 studies conducted in the United States of America, published within the years of 1999 to 2021. Parental education and socioeconomic status (e.g. income) were the most investigated disparities in PCI outcomes with 24 and 17 identified studies, respectively.

CONCLUSION

Socioeconomic status was a consistently reported determinant of PCI outcomes in the USA and elsewhere, and parental education, the most reported disparity, consistently impacted outcomes in countries outside the USA. This study is limited by our inability to perform a meta-analysis given the lack of standardization across measures of sociodemographic variables and assessment measures for PCI outcomes. Future studies should address the literature gap on racial and ethnic disparities among PCI outcomes and use standardized measures for sociodemographic variables and PCI outcomes to facilitate meta-analyses on the topic. Targeting the mechanisms of these disparities may mitigate the impact of the sociodemographic factors on PCI outcomes.

Factors Influencing Pediatric Cochlear Implant Outcomes: Carolina Sibling Study

OBJECTIVE

To determine the correlation between speech perception performance between pediatric sibling pairs with severe to profound sensory hearing loss receiving cochlear implants, and in cases of discordance in performance, determine which variables negatively impacted performance.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

SUBJECTS

Eighty-nine pediatric subjects, 43 sibling groups, under the age of 18 with severe to profound sensory hearing loss who received a cochlear implant with a sibling who also received a cochlear implant.

INTERVENTION

Cochlear implantation.

MAIN OUTCOME MEASURES

Speech perception scores, consonant-nucleus- consonant score.

RESULTS

A statistically significant correlation was found between speech perception performance of pediatric siblings. Depth of insertion is positively correlated with better speech perception in siblings with discordant results. There was no significant relationship with either electrode type, unilateral/bilateral status, or age of implantation.

CONCLUSION

Pediatric siblings have a high correlation in speech perception outcomes following cochlear implantation, suggesting family environment plays a strong role. In circumstances in which outcomes between siblings are substantially different, greater depth of implant insertion is correlated with better consonant-nucleus- consonant word scores.

Language evaluation in children with pre-lingual hearing loss and cochlear implant

Introduction

The cochlear implant is an effective device for children with severe and/or profound prelingual hearing loss, since it provides considerable improvement in oral language acquisition through the auditory pathway. The use of a cochlear implant contributes to the development of auditory perception, favoring the acquisition of the linguistic processes related to communication skills, which might have a positive effect on other areas of development.

Objective

The aim of this study was to verify the performance of children using cochlear implants for expressive and receptive oral language.

Methods

This was a prospective cross-sectional study that used the following tests: Child language test in the phonology, vocabulary, fluency and pragmatics areas, and the Peabody picture vocabulary test. Thirty children participated in this study, of both genders, aged between 36 and 72 months, with severe and/or profound bilateral sensorineural hearing loss, without other impairments and users of unilateral cochlear implant with full electrode insertion for a minimum of 12 months.

Results

The longer duration of the cochlear implant use, the younger age at surgery and the better performance in the auditory perception of speech influenced the performance in expressive and receptive oral language. Even though when compared to the normative language acquisition process, the results showed that these children had patterns of linguistic skills that are below their chronological age; the results indicate that these children are developing expressive and receptive oral language skills, and this is the outcome that should be taken into account in this study.

Conclusion

The longer duration of the cochlear implant use, the younger age at surgery and the better performance in the auditory perception of speech influenced the performance in expressive and receptive oral language skills, but not in all the studied semantic categories.

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.

Effects of residual hearing on cochlear implant outcomes in children: A systematic-review

OBJECTIVES

to investigate if preoperative residual hearing in prelingually deafened children can interfere on cochlear implant indication and outcomes.

METHODS

a systematic-review was conducted in five international databases up to November-2016, to locate articles that evaluated cochlear implantation in children with some degree of preoperative residual hearing. Outcomes were auditory, language and cognition performances after cochlear implant. The quality of the studies was assessed and classified according to the Oxford Levels of Evidence table - 2011. Risk of biases were also described.

RESULTS

From the 30 articles reviewed, two types of questions were identified: (a) what are the benefits of cochlear implantation in children with residual hearing? (b) is the preoperative residual hearing a predictor of cochlear implant outcome? Studies ranged from 04 to 188 subjects, evaluating populations between 1.8 and 10.3 years old. The definition of residual hearing varied between studies. The majority of articles (n = 22) evaluated speech perception as the outcome and 14 also assessed language and speech production.

CONCLUSION

There is evidence that cochlear implant is beneficial to children with residual hearing. Preoperative residual hearing seems to be valuable to predict speech perception outcomes after cochlear implantation, even though the mechanism of how it happens is not clear. More extensive researches must be conducted in order to make recommendations and to set prognosis for cochlear implants based on children preoperative residual hearing.

Cochlear implantation outcomes in children with common cavity deformity; a retrospective study

Objective

A common cavity deformity (CCD) is a deformed inner ear in which the cochlea and vestibule are confluent forming a common rudimentary cystic cavity that results in profound hearing loss. There are few studies paying attention to common cavity. Our group is engrossed in observing the improvement of auditory and verbal abilities in children who have received cochlear implantation (CI), and comparing these targets between children with common cavity and normal inner ear structure.

Material and methods

A retrospective study was conducted in 12 patients with profound hearing loss that were divided into a common cavity group and a control group, six in each group matched in sex, age and time of implantation, based on inner ear structure. Categories of Auditory Performance (CAP) and speech intelligibility rating (SIR) scores and aided hearing thresholds were collected and compared between the two groups. All patients wore CI for more than 1 year at the Cochlear Center of Anhui Medical University from 2011 to 2015.

Results

Postoperative CAP and SIR scores were higher than before operation in both groups (p < 0.05), although the scores were lower in the CCD group than in the control group (p < 0.05). The aided threshold was also lower in the control group than in the CCD group (p < 0.05).

Conclusion

Even though audiological improvement in children with CCD was not as good as in those without CCD, CI provides benefits in auditory perception and communication skills in these children.

Barriers to early cochlear implantation

OBJECTIVE

Identify variables associated with paediatric access to cochlear implants (CIs).

DESIGN

Part 1. Trends over time for age at CI surgery (N = 802) and age at hearing aid (HA) fitting (n = 487) were examined with regard to periods before, during, and after newborn hearing screening (NHS). Part 2. Demographic factors were explored for 417 children implanted under 3 years of age. Part 3. Pre-implant steps for the first 20 children to receive CIs under 12 months were examined.

RESULTS

Part 1. Age at HA fitting and CI surgery reduced over time, and were associated with NHS implementation. Part 2. For children implanted under 3 years, earlier age at HA fitting and higher family socio-economic status were associated with earlier CI. Progressive hearing loss was associated with later CIs. Children with a Connexin 26 diagnosis received CIs earlier than children with a premature / low birth weight history. Part 3. The longest pre-CI steps were Step 1: Birth to diagnosis/identification of hearing loss (mean 16.43 weeks), and Step 11: MRI scans to implant surgery (mean 15.05 weeks) for the first 20 infants with CIs under 12 months.

CONCLUSION

NHS implementation was associated with reductions in age at device intervention in this cohort.

Predictors of pediatric cochlear implantation outcomes in South Africa

OBJECTIVE

To identify and describe predictors of pediatric cochlear implantation outcomes in a South African population.

METHODS

A retrospective study of 301 pediatric cochlear implant (CI) recipients from five CI programs was conducted and cross-sectional outcome data were added at the time of data collection. Twenty potential prognostic factors were identified from the retrospective dataset, including demographical, CI, risk and family factors. Multiple regression analyses were performed to identify predictor variables that influence outcomes in terms of auditory performance (CAP scores), speech production (SIR scores), communication mode and educational placement.

RESULTS

Although implanted children within this sample did not have equal opportunity to access a second implant, bilateral implantation was strongly predictive of better auditory performance and speech production scores, an oral mode of communication and mainstream education. NICU admittance/prematurity were associated with poorer auditory performance and speech production scores, together with a higher probability for non-oral communication and non-mainstream education. The presence of one or more additional developmental condition was predictive of poorer outcomes in terms of speech production and educational placement, while a delay between diagnosis and implantation of more than one year was also related to non-mainstream education. Ethnicities other than Caucasian were predictive of poorer auditory performance scores and a lower probability for mainstream education.

CONCLUSION

An extensive range of prognostic indicators were identified for pediatric CI outcomes in South Africa. These predictive factors of better and poorer outcomes should guide pediatric CI services to promote optimal outcomes and assist professionals in providing evidence-based informational counseling.

Prelingual auditory-perceptual skills as indicators of initial oral language development in deaf children with cochlear implants

OBJECTIVES

To assess when prelingually deaf children with a cochlear implant (CI) achieve the First Milestone of Oral Language, to study the progression of their prelingual auditory skills in the first year after CI and to investigate a possible correlation between such skills and the timing of initial oral language development.

METHODS

The sample included 44 prelingually deaf children (23 M and 21 F) from the same tertiary care institution, who received unilateral or bilateral cochlear implants. Achievement of the First Milestone of Oral Language (FMOL) was defined as speech comprehension of at least 50 words and speech production of a minimum of 10 words, as established by administration of a validated Italian test for the assessment of initial language competence in infants. Prelingual auditory-perceptual skills were assessed over time by means of a test battery consisting of: the Infant Toddler Meaningful Integration Scale (IT-MAIS); the Infant Listening Progress Profile (ILiP) and the Categories of Auditory Performance (CAP).

RESULTS

On average, the 44 children received their CI at 24±9 months and experienced FMOL after 8±4 months of continuous CI use. The IT-MAIS, ILiP and CAP scores increased significantly over time, the greatest improvement occurring between baseline and six months of CI use. On multivariate regression analysis, age at diagnosis and age at CI did not appear to bear correlation with FMOL timing; instead, the only variables contributing to its variance were IT-MAIS and ILiP scores after six months of CI use, accounting for 43% and 55%, respectively.

CONCLUSION

Prelingual auditory skills of implanted children assessed via a test battery six months after CI treatment, can act as indicators of the timing of initial oral language development. Accordingly, the period from CI switch-on to six months can be considered as a window of opportunity for appropriate intervention in children failing to show the expected progression of their auditory skills and who would have higher risk of delayed oral language development.

[Evaluation of the results of cochlear implantation]

Les implants cochléaires sont des prothèses électro-acoustiques qui ont pour rôle de pallier une déficience bilatérale de l'oreille interne, qu'elle soit profonde ou sévère, acquise ou congénitale. Nous rapportons l'expérience du service d'Oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital universitaire Mohammed VI de Marrakech, dont l'objectif est d'évaluer l'implantation cochléaire et de préciser les facteurs influençant les résultats dans notre pratique. Le profil APCEI a été utilisé pour évaluer les résultats orthophoniques. Il s'agit d'une étude rétrospective étalée sur une période de 7 ans (Décembre 2007 à Décembre 2014). Durant cette période; 54 patients ont été implantés et suivient dans notre formation. Il s'agit de 30 filles et 24 garçons atteints d'une surdité sévères à profonde bilatérale, dont 48 enfants avaient une surdité pré-linguale. L'âge moyen d'implantation cochléaire pédiatrique était de 5,15 ans. L'implantation était unilatérale chez tous les patients. L'intervention était suivie par des réglages et une rééducation orthophonique régulière. L'évaluation était réalisée par la même équipe chaque mois durant les premiers 6 mois, puis tous les 6 mois. La durée moyenne de suivi était de 30,86 mois. Tous les patients ont tiré un bénéfice de leurs implants avec une variabilité interindividuelle. Les bons résultats étaient corrélés à l'implantation précoce, à un investissement parental important et au un bon suivi de la rééducation orthophonique. L'implantation cochléaire a révolutionnée la prise en charge de la surdité profonde et sévère. C'est une technique sûre, efficace lorsqu'elle s'adresse à des populations correctement sélectionnées.

Desenvolvimento da linguagem em crianças com implante coclear: terá o gênero alguma influência?

OBJECTIVO:avaliar a influencia do gênero no desenvolvimento da linguagem de crianças com surdez severa a profunda neurossensorial, após implante coclear.MÉTODOS:foram estudadas 30 crianças, 12 do gênero feminino e 18 do masculino, entre os 8 anos e 1 mês e os 10 anos com surdez severa a profunda neurossensorial bilateral congênita com implante coclear. Avaliaram-se as estruturas linguísticas semântica, morfossintaxe e fonologia. Utilizou-se o instrumento de avaliação: Grelha de Observação da Linguagem - nível escolar.RESULTADOS:a idade auditiva média foi de 72 meses no gênero feminino e 72.7 meses no masculino. As pontuações obtidas nos três níveis linguisticos foram estatisticamente semelhantes, quando comparados os gêneros. Nas provas de cada estrutura linguística também não se verificaram diferenças estatisticamente significantes.CONCLUSÕES:o gênero não influenciou o desenvolvimento da linguagem oral nas crianças utilizadoras de implante coclear, nas três estruturas linguísticas estudadas.

Narrative spoken language skills in severely hearing impaired school-aged children with cochlear implants

Cochlear implants have a significant positive effect on spoken language development in severely hearing impaired children. Previous work in this population has focused mostly on the emergence of early-developing language skills, such as vocabulary. The current study aims at comparing narratives, which are more complex and later-developing spoken language skills, of a contemporary group of profoundly deaf school-aged children using cochlear implants (n=66, median age=8 years 3 months) with matched normal hearing peers. Results show that children with cochlear implants demonstrate good results on quantity and coherence of the utterances, but problematic outcomes on quality, content and efficiency of retold stories. However, for a subgroup (n=20, median age=8 years 1 month) of deaf children without additional disabilities who receive cochlear implantation before the age of 2 years, use two implants, and are raised with one spoken language, age-adequate spoken narrative skills at school-age are feasible. This is the first study to set the goals regarding spoken narrative skills for deaf children using cochlear implants.

A novel frameshift mutation (c.405delC) in the GJB2 gene associated with autosomal recessive hearing loss in two Tunisian families

OBJECTIVES

Mutations in GJB2 are found to be responsible for 50% of congenital autosomal recessive non-syndromic hearing loss, one of the most important mutations in this gene is the c.35delG, which is responsible for the majority of GJB2 related deafness in the Tunisian population. The aim of this study was to determine the molecular etiology of hearing loss in two Tunisian individuals.

METHODS

We screened two Tunisian individuals affected by congenital, bilateral, profound, sensorineural hearing loss for mutations in GJB2 gene using PCR and direct sequencing.

RESULTS

We identified a novel frameshift mutation in the GJB2 gene, the c.405delC resulting in a truncated protein (p.Tyr136Thrfs*32). It was found in compound heterozygosity with the c.35delG in two non-consanguineous unrelated families from Tunisia. One patient underwent a cochlear implant at 4 years. Initial evaluations post-implantation indicate a successful cochlear implant outcome since the patient began to acquire language abilities and auditory sensation.

CONCLUSIONS

With this novel GJB2 mutation, the mutational spectrum of this gene continues to broaden in our population. The occurrence of biallelic GJB2 mutations for the other deaf girl, despite the neonatal pain and hypotension due to complicated delivery, led us to confirm the importance of GJB2 screening for cochlear implant candidates regardless of the etiology of deafness in populations with a relatively high frequency of GJB2 mutation carriers.

Compound heterozygosity for dominant and recessive GJB2 mutations in a Tunisian family and association with successful cochlear implant outcome

OBJECTIVES

Mutations of GJB2 encoding connexin 26 are the most common cause of hearing loss. They are responsible for up to 50% of ARNSHL. The pathogenic mutations in this gene are generally inherited recessively. Dominant mutations in GJB2 also cause hearing loss, either in isolated non-syndromic form or as part of a syndrome associated with various skin disorders.

METHODS

We screened a Tunisian child affected by congenital, bilateral, profound, sensorineural hearing loss for mutations in GJB2 gene using PCR and direct sequencing.

RESULTS

The proband was found to be compound heterozygous for recessive and dominant GJB2 mutations respectively p.V37I (c.109G > A) and p.R143Q (c.428G > A). Surprisingly the hearing mother is a carrier for this dominant GJB2 mutation. This proband underwent a cochlear implant at four years old. The evaluation using APCEI and IT-MAIS tests at six months post implantation indicates a successful cochlear implant outcome since the deaf child began to acquire language abilities and auditory sensation.

CONCLUSIONS

The p.R143Q mutation was described for the first time in Tunisia. We confirm the low penetrance of this mutation since the proband mother is a carrier despite her normal hearing. We show the effectiveness of cochlear implant to restore the communication abilities and auditory sensation for our patient.

Young cochlear implant users' auditory development as measured and monitored by the LittlEARS® Auditory Questionnaire: a Turkish experience

OBJECTIVE

This study aims to assess the usefulness of the LittlEARS(®) Auditory Questionnaire (LEAQ) in determining the audiological development of Turkish children who have received a cochlear implant.

METHODS

20 children received a cochlear implant before their 3rd birthday. Each child's progress was evaluated with the LittlEARS(®) Auditory Questionnaire at first device fitting and then at 3-month intervals for 2 years. Scores were compared with the age-related norms established by hearing children.

RESULTS

All children showed a significant increase in LittlEARS(®) Auditory Questionnaire scores over time. Nearly all children showed a growth in auditory skills similar to that of hearing children. Children without additional needs showed more development than did children with additional needs.

CONCLUSIONS

The LittlEARS(®) Auditory Questionnaire is useful for monitoring the audiological development of young children with a cochlear implant. Confirmation that a cochlear implant user is achieving typical auditory milestones serves to boost parental morale during a child's pre-verbal stage when parents may be anxious about their child's ability to talk. The questionnaire could also be useful as an early warning system. Poor scores likely indicate that something is impeding the child's development. This should prompt professionals to try to identify the impediment, whether technical, medical, social or educational and, possibly, eliminate/mitigate its effects while the child is still in his/her critical development stages.

Cochlear implant considerations in children with additional disabilities

Early identification and management of disabilities in children are essential to reduce long-term developmental sequelae. Many of the causes of hearing loss also produce cognitive delays resulting in a large number of children with both deafness and developmental disabilities. Children who have hearing loss and additional disabilities require complex, individualized therapy to maximize their long-term quality of life. Hearing loss is often detected early because of widespread newborn hearing screening programs and the decision for cochlear implantation in children presenting with multiple medical and developmental disorders is still evolving. This article will review the literature regarding cochlear implant considerations in children with additional developmental disabilities in areas of family perception, speech and language development, cognitive development including adaptive behavior and intelligence, communication and functional skills, auditory outcomes, quality of life outcomes, predictors of outcomes and realistic expectations after cochlear implantation.

Prediction of cochlear implant performance by genetic mutation: the spiral ganglion hypothesis

BACKGROUND

Up to 7% of patients with severe-to-profound deafness do not benefit from cochlear implantation. Given the high surgical implantation and clinical management cost of cochlear implantation (>$1 million lifetime cost), prospective identification of the worst performers would reduce unnecessary procedures and healthcare costs. Because cochlear implants bypass the membranous labyrinth but rely on the spiral ganglion for functionality, we hypothesize that cochlear implant (CI) performance is dictated in part by the anatomic location of the cochlear pathology that underlies the hearing loss. As a corollary, we hypothesize that because genetic testing can identify sites of cochlear pathology, it may be useful in predicting CI performance.

METHODS

29 adult CI recipients with idiopathic adult-onset severe-to-profound hearing loss were studied. DNA samples were subjected to solution-based sequence capture and massively parallel sequencing using the OtoSCOPE(®) platform. The cohort was divided into three CI performance groups (good, intermediate, poor) and genetic causes of deafness were correlated with audiometric data to determine whether there was a gene-specific impact on CI performance.

RESULTS

The genetic cause of deafness was determined in 3/29 (10%) individuals. The two poor performers segregated mutations in TMPRSS3, a gene expressed in the spiral ganglion, while the good performer segregated mutations in LOXHD1, a gene expressed in the membranous labyrinth. Comprehensive literature review identified other good performers with mutations in membranous labyrinth-expressed genes; poor performance was associated with spiral ganglion-expressed genes.

CONCLUSIONS

Our data support the underlying hypothesis that mutations in genes preferentially expressed in the spiral ganglion portend poor CI performance while mutations in genes expressed in the membranous labyrinth portend good CI performance. Although the low mutation rate in known deafness genes in this cohort likely relates to the ascertainment characteristics (postlingual hearing loss in adult CI recipients), these data suggest that genetic testing should be implemented as part of the CI evaluation to test this association prospectively.

Measuring communicative performance with the German version of the FAPCI-instrument: normative data and longitudinal results

OBJECTIVE

The German version of the Functioning after Paediatric Cochlear Implantation (FAPCI) inventory was designed to capture the communicative performance of cochlear implanted children. In order to be able to compare cochlear-implanted children to their normal hearing peers, normative growth curves were designed. Furthermore it was of interest how the communicative performance develops over time and whether it is influenced by age at implantation.

METHOD

A polynomial regression curve was fit to the data of 133 normal hearing children. This normative curve was compared to individual growth curves of 90 cochlear implanted children. The cochlear-implanted study sample was split up into four groups depending on the age at implantation.

RESULTS

The normative growth curve increases from 1 year of age until saturation is reached with 3 years of age. The individual FAPCI trajectories of cochlear implanted children are heterogeneous, but in general they are delayed in comparison to the normative growth curve. "Early implanted children" follow the development of their normal hearing peers more closely than "later-implanted children".

CONCLUSION

The German version of the FAPCI parental questionnaire constitutes an additional instrument in monitoring the communicative performance development of cochlear implanted children and allows for comparison to normal hearing peers.