Advantages of Cochlear Implantation in Prelingual Deaf Children before 2 Years of Age when Compared with Later Implantation

Neurocognitive outcomes in young adults with cochlear implants: The role of early language access and crossmodal plasticity

Many children with profound hearing loss have received cochlear implants (CI) to help restore some sense of hearing. There is, however, limited research on long-term neurocognitive outcomes in young adults who have grown up hearing through a CI. This study compared the cognitive outcomes of early-implanted (n = 20) and late-implanted (n = 21) young adult CI users, and typically hearing (TH) controls (n=56), all of whom were enrolled in college. Cognitive fluidity, nonverbal intelligence, and American Sign Language (ASL) comprehension were assessed, revealing no significant differences in cognition and nonverbal intelligence between the early and late-implanted groups. However, there was a difference in ASL comprehension, with the late-implanted group having significantly higher ASL comprehension. Although young adult CI users showed significantly lower scores in a working memory and processing speed task than TH age-matched controls, there were no significant differences in tasks involving executive function shifting, inhibitory control, and episodic memory between young adult CI and young adult TH participants. In an exploratory analysis of a subset of CI participants (n = 17) in whom we were able to examine crossmodal plasticity, we saw greater evidence of crossmodal recruitment from the visual system in late-implanted compared with early-implanted CI young adults. However, cortical visual evoked potential latency biomarkers of crossmodal plasticity were not correlated with cognitive measures or ASL comprehension. The results suggest that in the late-implanted CI users, early access to sign language may have served as a scaffold for appropriate cognitive development, while in the early-implanted group early access to oral language benefited cognitive development. Furthermore, our results suggest that the persistence of crossmodal neuroplasticity into adulthood does not necessarily impact cognitive development. In conclusion, early access to language - spoken or signed - may be important for cognitive development, with no observable effect of crossmodal plasticity on cognitive outcomes.

The use of a computer-based program focused on the syllabic method to support early literacy in children with cochlear implants

BACKGROUND

Children with cochlear implants (CIs) often lag behind children with normal hearing (NH) in early literacy skills. Furthermore, the development of language skills associated with their emergent literacy skills seems to depend on good auditory access. Supporting language acquisition and early literacy in children with CIs may prevent difficulties in primary school. The use of technology may facilitate auditory and speech recovery in children with CIs, but evidence on computer-based early literacy programs is limited.

OBJECTIVE

This study investigates (a) the effects of a computer-based program focusing on the syllabic method on the literacy skills of children with CIs (CIs group), comparing them with the literacy skills of a group of age-matched NH (normal hearing) peers (NHs group); (b) the associations between language and early literacy skills in the NHs group and between language, auditory and early literacy skills in the CIs group.

METHOD

Nine prelingually deaf children with CIs (M = 61.11, SD = 6.90) with severe to profound sensorineural hearing loss and nine age-matched NH children participated in the program. Categories of Auditory Performance (CAP) as measures of children's auditory skills were collected. All participants were tested on phonological, morphosyntax (grammatical comprehension and repetition), and early literacy skills (syllable blending and segmentation, syllable and word reading) (T1). Next, all children participated in the computer-based program for 12 weeks. After the program was completed (T2), only early literacy tests were administered to the children.

RESULTS

Although, on average, both groups obtained higher scores in all literacy tasks at T2, the CIs group scored lower than the NHs group. In the CIs group, at T2 we found significant improvements in syllable segmentation (p = 0.042) and word reading (p = 0.035). In the NHs group, at T2 we found significant improvements in syllable segmentation (p = 0.034), syllable blending (p = 0.022), syllable reading (p = 0.008), and word reading (p = 0.009). We also found significant associations in both groups between measures of morphosyntax at T1 and measures of early literacy at T2. In addition, for the CIs group, we found significant associations between children's auditory performance at T1 and measures of morphosyntax at T1 and early literacy at T2.

CONCLUSION

a computer-based program focused on the syllabic method could support children with CIs in acquiring emergent literacy abilities. The auditory performance of children with CIs seems to influence their morphosyntax and later early literacy skills.

Efficacy of cochlear implantation in cochlear nerve deficiency children - A single center study

PURPOSES

The objective of this research was to interpret and analyze the imaging, audiological features and cochlear implantation outcomes in cochlear nerve deficiency children.

MATERIAL AND METHODS

Retrospective analysis.

RESULTS

25 prelingual hearing loss children diagnosed cochlear nerve deficiency (CND), the age range from 1 to 15 (mean age, 5.04), underwent cochlear implantation at Ear Nose and Throat Hospital - Ho Chi Minh City (ENT hospital - HCMC) from 2016 to 2023. All children had sensorineural hearing loss (SNHL) from severe to profound degree. Magnetic resonance imaging (MRI) showed cochlear nerve hypoplasia in 76 % and cochlear nerve aplasia in 24 % of cases. Inner ear malformations were found in 52 % of cases. The mean Categories of Auditory Performance (CAP) score at 1 year after surgery was 4.8. At 6 months and 1 year after surgery, the mean CAP score of the aplasia group was significantly lower than that of the hypoplasia group (p < 0.05).

CONCLUSIONS

In cochlear nerve deficiency children, auditory perception and speech performance still improved after cochlear implantation. However, this progress was significantly limited in cochlear nerve aplasia group.

Selection of the optimal first ear for sequential bilateral cochlear implantation in children

OBJECTIVES

When there is a difference in hearing on both ears, where to perform the first cochlear implantation (CI) becomes an important issue. The purpose of the study was to evaluate which ear should be chosen for the first implantation in sequential bilateral CI with a long inter-implant period.

METHODS

The study population consisted of 34 severe-to-profound sensorineural hearing loss pediatrics with the inter-implant period of ≥3 years between the first CI (CI-1) and the second CI (CI-2) before the age of 19 (mean of inter-implant period: 7.1-year). The patients were classified into Group A (CI-1 was performed on the ear with better hearing), Group B (CI-1 on the ear with worse hearing), or Group C (symmetrical hearing in both ears). Speech intelligibility test results were compared between the groups.

RESULTS

The monosyllabic word scores of CI-1 were excellent in Groups A (91.7±7.9%) and B (92.5±3.6%) but slightly lower in Group C (85.7±14.9%) before the second implantation (P = .487). At 3 years after the second implantation, all groups demonstrated excellent scores in the bilateral CI condition (95.9±3.0% in Group A; 99.1±.8% in Group B; 97.5±2.9% in Group C, P = .600). However, when the patients were tested in using CI-2 only in Groups A and B after using bilateral CI for 3 years, the scores were inconsistent in Group A (79.6±23.9%; range: 22.2-94.4%), while those were higher and more constant in Group B (92.9±4.8%; 86.8-100.0%).

CONCLUSIONS

The first CI is strongly recommended to perform on a worse hearing ear if they had different hearing levels between ears. Even with the first CI on a worse hearing ear, its performance never deteriorates. In addition, if they receive the second CI several years later, it will be likely that the second one functions better.

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.

A Modified Pediatric Ranked Order Speech Perception Score to Assess Speech Recognition Development in Children With Cochlear Implants

PURPOSE

Characterizing and comparing speech recognition development in children with cochlear implants (CIs) is challenging because of variations in test type. This retrospective cohort study modified the Pediatric Ranked Order Speech Perception (PROSPER) scoring system to (a) longitudinally analyze the speech perception of children with CIs and (b) examine the role of age at CI activation, listening mode (i.e., unilateral or bilateral implantation), and interimplant interval.

METHOD

Postimplantation speech recognition scores from 31 children with prelingual, severe-to-profound hearing loss who received CIs were analyzed (12 with unilateral CI [UniCI], 13 with sequential bilateral CIs [SEQ BiCIs], and six with simultaneous BiCIs). Data were extracted from the Massachusetts Eye and Ear Audiology database. A version of the PROSPER score was modified to integrate the varying test types by mapping raw scores from different tests into a single score. The PROSPER scores were used to construct speech recognition growth curves of the implanted ears, which were characterized by the slope of the growth phase, the time from activation to the plateau onset, and the score at the plateau.

RESULTS

While speech recognition improved considerably for children following implantation, the growth rates and scores at the plateau were highly variable. In first implanted ears, later implantation was associated with poorer scores at the plateau (β = -0.15, p = .01), but not growth rate. The first implanted ears of children with BiCIs had better scores at the plateau than those with UniCI (β = 0.59, p = .02). Shorter interimplant intervals in children with SEQ BiCIs promoted faster speech recognition growth of the first implanted ears.

CONCLUSION

The modified PROSPER score could be used clinically to track speech recognition development in children with CIs, to assess influencing factors, and to assist in developing and evaluating patient-specific intervention strategies.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20113538.

Recognizing Voices Through a Cochlear Implant: A Systematic Review of Voice Perception, Talker Discrimination, and Talker Identification

OBJECTIVE

Some cochlear implant (CI) users report having difficulty accessing indexical information in the speech signal, presumably due to limitations in the transmission of fine spectrotemporal cues. The purpose of this review article was to systematically review and evaluate the existing research on talker processing in CI users. Specifically, we reviewed the performance of CI users in three types of talker- and voice-related tasks. We also examined the different factors (such as participant, hearing, and device characteristics) that might influence performance in these specific tasks.

DESIGN

We completed a systematic search of the literature with select key words using citation aggregation software to search Google Scholar. We included primary reports that tested (a) talker discrimination, (b) voice perception, and (c) talker identification. Each report must have had at least one group of participants with CIs. Each included study was also evaluated for quality of evidence.

RESULTS

The searches resulted in 1,561 references, which were first screened for inclusion and then evaluated in full. Forty-three studies examining talker discrimination, voice perception, and talker identification were included in the final review. Most studies were focused on postlingually deafened and implanted adult CI users, with fewer studies focused on prelingual implant users. In general, CI users performed above chance in these tasks. When there was a difference between groups, CI users performed less accurately than their normal-hearing (NH) peers. A subset of CI users reached the same level of performance as NH participants exposed to noise-vocoded stimuli. Some studies found that CI users and NH participants relied on different cues for talker perception. Within groups of CI users, there is moderate evidence for a bimodal benefit for talker processing, and there are mixed findings about the effects of hearing experience.

CONCLUSIONS

The current review highlights the challenges faced by CI users in tracking and recognizing voices and how they adapt to it. Although large variability exists, there is evidence that CI users can process indexical information from speech, though with less accuracy than their NH peers. Recent work has described some of the factors that might ease the challenges of talker processing in CI users. We conclude by suggesting some future avenues of research to optimize real-world speech outcomes.

Outcomes of Hearing Aid and Cochlear Implantation in Case of Congenital Non-Syndromic Bilateral Severe to Profound Sensorineural Hearing Loss: An Observational Study

This study was done to measure the outcomes of hearing aid (HA) and cochlear implantation (CI) in case of congenital non syndromic severe to profound sensorineural hearing loss (SNHL) by using aided audiometry (AA), categories of auditory perception (CAP) score and speech intelligibility rating (SIR) scale. The objectives were to find out the effective management options available for bilateral severe to profound SNHL, to study the impact of age of CI on language development and to study the outcome of HA and CI. Patients with congenital severe to profound SNHL were included in the study. Initially the case history of the participants was taken then they underwent audiological tests to confirm hearing loss. To assess the outcomes of HA and CI, they were initially fitted with high gain digital behind the ear HA, then underwent auditory verbal therapy for twelve months, after that AA, CAP and SIR test done to measure the outcomes of HA and similar hierarchy followed for CI. The results showed that with HA, the benefit is very limited whereas with CI the benefit is significant. The average SIR score of HA and CI are 1 and 3.16 and average CAP score are 0.83 and 7.8 respectively. The study shows that the CI is one of the most effective management options available for severe to profound SNHL and found that early intervention followed by early detection of hearing loss helps in achieving better speech and language skills.

Language and Audiological Outcomes Among Infants Implanted Before 9 and 12 Months of Age Versus Older Children: A Continuum of Benefit Associated With Cochlear Implantation at Successively Younger Ages

OBJECTIVE

To compare language and audiological outcomes among infants (<9 and <12 mo) and older children receiving cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

Pediatric patients receiving CI between October 1995 and October 2019.

INTERVENTION

Cochlear implantation.

MAIN OUTCOME MEASURES

Most recent language and audiological assessment scores were evaluated by age group.

RESULTS

A total of 118 children were studied, including 19 who were implanted <9 months of age, 19 implanted 9 to <12 months of age, and 80 implanted 12 to <36 months of age. The mean duration of follow-up was 7.4 ± 5.0 years. Most recent REEL-3 receptive (88 ± 12 vs. 73 ± 15; p = 0.020) and expressive (95 ± 13 vs. 79 ± 12; p = 0.013) communication scores were significantly higher in the <9 months group compared to the 9 to <12 months group. PLS and OWLS auditory comprehension and oral expression scores were significantly higher in the <12 months group compared to the 12 to <36 months group. The difference in NU-CHIPS scores between <12 and 12 to <36 months was statistically significant (89% ± 6 vs. 83% ± 12; p = 0.009). LNT scores differed significantly between <9 and 9 to <12 months (94% ± 4 vs. 86% ± 10; p = 0.028).

CONCLUSIONS

The recent FDA expansion of pediatric CI eligibility criteria to include infants as young as 9 months of age should not serve as a strict clinical cutoff. Rather, CI can be pursued in appropriately selected younger infants to optimize language and audiological outcomes.

Early pediatric Cochlear implantation: An update

The criteria and candidacy for pediatric cochlear implantation (CI) has significantly transformed over the past few decades and continues to evolve with technological advancements, and recognition of benefit in more diverse populations. Prolonged auditory deprivation among patients with profound sensorineural hearing loss has been shown to cause widespread degeneration in the central auditory system. Thus, there is increasing evidence advocating for earlier implantation within a critical neuroplastic window. However, there is a lack of consensus on this optimal age of implantation. Historically, there were concerns regarding surgical feasibility and safety, anesthesia risk, and logistical considerations in very young infants <12 months. Recent literature has investigated surgical safety and anesthesia risk as well speech and language outcomes with early implantation, resulting in the long-awaited reduction in approved age by the FDA (<9 months for certain devices). This article reviews logistical considerations, surgical safety, anesthesia risk, and language developmental outcomes associated with early CI (<12 months).

Early pediatric Cochlear implantation: An update

The criteria and candidacy for pediatric cochlear implantation (CI) has significantly transformed over the past few decades and continues to evolve with technological advancements, and recognition of benefit in more diverse populations. Prolonged auditory deprivation among patients with profound sensorineural hearing loss has been shown to cause widespread degeneration in the central auditory system. Thus, there is increasing evidence advocating for earlier implantation within a critical neuroplastic window. However, there is a lack of consensus on this optimal age of implantation. Historically, there were concerns regarding surgical feasibility and safety, anesthesia risk, and logistical considerations in very young infants <12 months. Recent literature has investigated surgical safety and anesthesia risk as well speech and language outcomes with early implantation, resulting in the long-awaited reduction in approved age by the FDA (<9 months for certain devices). This article reviews logistical considerations, surgical safety, anesthesia risk, and language developmental outcomes associated with early CI (<12 months).

Hearing and speech benefits of cochlear implantation in children: A review of the literature

Cochlear implantation is a safe and reliable treatment for children with severe to profound hearing loss. The primary benefit of these medical devices in children is the acquisition of hearing, which promotes development of spoken language. The present paper reviews published literature demonstrating predictive effects of a number of factors on acquisition of hearing development and speech recognition. Of the many variables that contribute to an individual child's development after implantation, age at implantation, the presence of medical comorbidities, social determinants of health, and the provision of bilateral versus unilateral hearing are those that can vary widely and have consistently shown clear impacts. Specifically, age of implantation is crucial to reduce effects of deafness on the developing auditory system and capture the remarkable plasticity of early development. Language development after cochlear implantation requires therapy emphasizing hearing and oral communication, education, and other support which can be influenced by known social determinants of health; specifically, outcomes in children decline with reductions in socioeconomic status and levels of parental education. Medical co-morbidities also slow rates of progress after cochlear implantation. On the other hand, benefits of implantation increase in children who are provided with access to hearing from both ears. In sum, cochlear implants promote development of hearing in children and the best outcomes are achieved by providing early access to sound in both ears. These benefits can be limited by known social determinants of health which restrict access to needed support and medical comorbidities which add further complexity in care and outcome.

Does early cochlear implantation promote better reading comprehension skills?

OBJECTIVE

to investigate the effect of age at CI activation and to explore the role of other variables such as linguistic skills, stimulation modality and gender on reading comprehension.

STUDY DESIGN

Prospective observational nonrandomized study.

METHODS

89 children with profound congenital sensorineural hearing loss were included in the study. The mean age at CI activation was 21 months (DS ± 11; range 7-50). The Italian reading standardized test, "Prove di lettura MT", was used to assess reading comprehension. The individual raw data MT score were converted into z scores (expected values: means = 0 and SD = 1). The positive values indicated better performance and negative values indicated worse performance.

RESULTS

Early implanted children achieved significantly better reading comprehension skills, 55 out of 89 children are within 1 SD from the overall mean. 34 children (38.2%) attainted MT z-scores less than 1 SD below the mean. Children with unilateral CI performed somewhat worse if compared to bilateral CI and bimodal stimulation mode, although the differences were weakly significant from a statistical point of view. A strong and positive correlation (rho .69, p < .001) was found with the lexical and morphosyntactic comprehension (rho .70, p < .001). Not significantly different values were observed for gender and parental education level.

CONCLUSION

Early cochlear implantation promoted better development of reading skills in children with cochlear implantation. LEVEL OF EVIDENCES: outcomes research.

Prelingual Deaf Children Treated With Cochlear Implant: Monitoring Performance With Percentiles

OBJECTIVES

To develop a percentile ranking system driven by speech recognition data obtained from different groups of patients treated with a cochlear implant to serve as a tool to monitor the progress of these patients.

STUDY DESIGN

Prospective study.

SETTING

Tertiary referral center.

PATIENTS

Diagnosed with a bilateral, profound sensorineural hearing loss treated with a unilateral cochlear implant.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURE

Six different percentiles (p) were classified taking into account the correlation between speech recognition outcome scores and age at implantation, with reference to the onset of hearing loss.

RESULTS

Four hundred sixteen prelingual patients were included. These subjects were divided into subgroups depending on age at implantation.Prelingual group, from the fifth year after implantation, p50 centered on the following percentages of correct words in each subgroup: 100, 94.6, 91.4, 91.0, 79.2, and 63.1% in children implanted under 12 months, 1, 2, 3, 4 to 6, 7 to 10 years, respectively. After a 12-year follow-up, a significant negative correlation between age at implantation and speech recognition was observed in both prelinguals (Rhos=-0.578, p<0.001).

CONCLUSION

A percentile system was developed to monitor the postimplant progress of prelingual deaf implanted patients, with potential applications in patient follow-up and handling circumstances that may deteriorate results.

Assessment of temporal processing functions in early period cochlear implantation

PURPOSE

The purpose of this study is to compare the temporal processing performance of children with cochlear implant (CI) according to the age of implantation and to determine their relation with auditory perception scores.

METHODS

In this study, 30 cochlear implant users and ten normal hearing children at 9 and 10 years were included. Children with cochlear implants are divided into two groups according to the age of implantation: group I includes participants whose implantation age is between 13 and 35 months (20 children), group II includes participants whose implantation age is between 36 and 45 months (10 children). Individuals were evaluated with random gap detection test (RGDT), duration pattern test (DPT), frequency pattern test (FPT), the Mr. Potato Head task, word recognition, and sentence recognition test.

RESULTS

A significant difference was found between the control and CI groups in temporal processing performance. The temporal processing ability of CI groups was significantly worse than those of normal hearing. Although there was no significant difference among the groups with cochlear implant in terms of temporal processing performance, children who started to use CI at an earlier age showed a tendency of better performance on temporal processing tasks. There was a significant relationship between Daily Sentence Test and FPT, and the Mr. Potato Head task and FPT rev (the score calculated by accepting the reverse patterns correctly). There was a significant relationship between duration of implant use and temporal ordering performance CONCLUSION: In this study, children with CI cannot perform as well as normal-hearing peers on temporal processing tasks, even if they had started to use their CIs at an early age. It is important to evaluate temporal processing in implanted individuals and to guide auditory training considering the evaluation results.

Effects of Age at Cochlear Implantation on Vocabulary and Grammar: A Review of the Evidence

Purpose The increasing prevalence of pediatric cochlear implantation over the past 25 years has left little doubt that resulting improvements in hearing offer significant benefits to language development for many deaf children. Furthermore, given the documented importance of access to language from birth, there has been strong support for providing congenitally deaf children with implants as early as possible. Earliest implantation, in many ways, has become the "gold standard" in pediatric cochlear implantation, on the assumption that it is the key to language development similar to that of hearing children. Empirical evidence to support this assumption, however, appears more equivocal than generally is believed. This article reviews recent research aimed at assessing the impact of age at implantation on vocabulary and grammatical development among young implant users. Method Articles published between 2003 and 2018 that included age at implantation as a variable of interest and in which it was subjected to statistical analysis were considered. Effect sizes were calculated whenever possible; we conducted a multivariate meta-analysis to compare outcomes in different language domains. Results Taken together, findings from 49 studies suggest that age at implantation is just one of a host of variables that influence vocabulary and grammatical development, its impact varying with several factors including whether age at implantation is treated as a dichotomous or continuous variable. Results from a meta-analysis showed significant differences across language domains. Conclusion The pattern of results obtained indicates the importance of considering various child, family, and environmental characteristics in future research aimed at determining how early "early implantation" needs to be and the extent to which age at implantation, duration of implant use, and other factors influence language and language-related outcomes. Supplemental Material https://doi.org/10.23641/asha.9789041.

Parent-perceived challenges related to the pediatric cochlear implantation process and support services received in South Africa

OBJECTIVE

To determine and describe parent-perceived challenges related to the pediatric cochlear implantation process and support services received.

METHOD

A multicenter survey study across six cochlear implant (CI) programs in South Africa (SA) was conducted. The study sample included 82 parents of pediatric (≤18 years) CI recipients with at least 12 months CI experience. A self-administered questionnaire was developed for the purpose of this study, exploring parental challenges regarding the CI process, education of their implanted children and the support services received.

RESULTS

The financial implications of cochlear implantation, including CI device maintenance, were identified by parents as the most prominent challenge. Financing issues were the highest scoring reason that attributed to the delay between diagnosis of hearing loss and cochlear implantation, as well as the greatest barrier to bilateral implantation. Parent-perceived educational challenges included finding adequate educational settings specific to the individual needs of their child and a shortage of trained teachers equipped to support children with CIs. The presence of one/more additional developmental conditions and grade repetition were associated with more pronounced parent-perceived educational challenges. Parents considered speech-language therapy as the most critical support service for their implanted children to achieve optimal outcomes, while parent guidance was indicated to be the most critical support service required for parents of pediatric CI recipients.

CONCLUSION

A greater understanding of parent-perceived challenges will guide CI professionals to promote optimal outcomes, evidence-based service delivery and on-going support to pediatric CI recipients and their families. Study results imply a call for action regarding financial and educational support for pediatric CI recipients in SA.

Speech Perception Growth Patterns in Prelingual Deaf Children With Bilateral Sequential Cochlear Implantation

OBJECTIVE

To evaluate speech perception following the first (CI-1) and second (CI-2) cochlear implantation (CI) in children with sequential bilateral CI.

STUDY DESIGN

Retrospective.

PATIENTS

Seventy children with follow-up for 60 months post CI-1 and 36 months post CI-2.

MAIN OUTCOME MEASURES

Word recognition score (WRS) was the main outcome. WRSs were compared by age at CI operation (group A ≤ 3.5 yr, B 3.6-8.6, for CI-1; group I ≤ 3.5 yr, II 3.6-7.0, III 7.1-13, IV > 13, for CI-2).

RESULTS

For CI-1, the WRS of group A exceeded 80% at 24 months post procedure, earlier than group B (54 mo). Group A also had a shorter period of CI-1 use up to the WRS plateau than group B. CI-2 showed an initial burst of WRS growth much earlier than CI-1. This initial burst was most robust within 3 months in group II, but modest in group IV. The periods of CI-2 use (11-17 mo) up to the WRS plateau were much shorter than CI-1 (40-64 mo). Group I did not show the best WRS at 1 month post CI but later exceeded the other groups.

CONCLUSION

Children received an immediate benefit by a burst of WRS growth from CI-2 earlier than CI-1, even within 3 months, suggesting that CI-1 gets the auditory cortex ready to foster speech processing from CI-2. The CI-2 performance depends on age at CI-2 implantation and on CI-1 performance. Our current findings will be relevant for clinicians who are counselling parents on CI-2 surgery.

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.

Cochlear Implantation for Children and Adults with Severe-to-Profound Hearing Loss

Cochlear implants (CIs) have proven to be a useful treatment option for individuals with severe-to-profound hearing loss by providing improved access to one's surrounding auditory environment. CIs differ from traditional acoustic amplification by providing information to the auditory system via electrical stimulation. Both postlingually deafened adults and prelingually deafened children can benefit from a CI; however, outcomes with a CI can vary. Numerous factors can impact performance outcomes with a CI. It is important for the audiologist to understand what factors might play a role and impact performance outcomes with a CI so that they can effectively counsel the recipient and their family, as well as establish appropriate and realistic expectations with a CI. This review article will discuss the CI candidacy process, CI programming and postoperative follow-up care, as well as considerations across the lifespan that may affect performance outcomes with a CI.

The Advances in Hearing Rehabilitation and Cochlear Implants in China

Hearing loss (HL) is a common sensory impairment in humans, with significant economic and social impacts. With nearly 20% of the world's population, China has focused on economic development and health awareness to improve the care for its hearing-impaired population. Recently, the Chinese government has initiated national programs such as the China Disabled Persons Federation to fund prevention, treatment, and rehabilitation of hearing impairment. Newborn hearing screening and auditory rehabilitation programs in China have expanded exponentially with government support. While facing many challenges and overcoming obstacles, cochlear implantation (CI) programs in China have also experienced considerable growth. This review discusses the implementation of CI programs for HL in China and presents current HL data including epidemiology, newborn hearing screening, and determination of genetic etiologies. Sharing the experience in Chinese auditory rehabilitation and CI programs will shine a light on the developmental pathway of healthcare infrastructure to meet emerging needs of the hearing-impaired population in other developing countries.

Guideline on cochlear implants

INTRODUCTION

In the last decade numerous hospitals have started to work with patients who are candidates for a cochlear implant (CI) and there have been numerous and relevant advances in the treatment of sensorineural hearing loss that extended the indications for cochlear implants.

OBJECTIVES

To provide a guideline on cochlear implants to specialists in otorhinolaryngology, other medical specialities, health authorities and society in general.

METHODS

The Scientific Committees of Otology, Otoneurology and Audiology from the Spanish Society of Otolaryngology and Head and Neck Surgery (SEORL-CCC), in a coordinated and agreed way, performed a review of the current state of CI based on the existing regulations and in the scientific publications referenced in the bibliography of the document drafted.

RESULTS

The clinical guideline on cochlear implants provides information on: a) Definition and description of Cochlear Implant; b) Indications for cochlear implants; c) Organizational requirements for a cochlear implant programme.

CONCLUSIONS

A clinical guideline on cochlear implants has been developed by a Committee of Experts of the SEORL-CCC, to help and guide all the health professionals involved in this field of CI in decision-making to treathearing impairment.

Survey on the knowledge of cochlear implant indication in the treatment of hearing loss in Spain

INTRODUCTION

This study aims to analyse the knowledge of cochlear implant (CI) candidacy criteria of otorhinolaryngology specialists in Spain, and from the results, consider whether it is necessary to implement training measures aimed at improving knowledge in this area.

MATERIAL AND METHODS

A questionnaire was designed for measuring the level of knowledge of cochlear implant candidacy criteria (CI) in people with hearing loss. The questionnaire collected the demographic data of the respondents and their knowledge on the conventional and emergency indications for CI, technical characteristics of CI and results in the implanted population.

RESULTS

A total of 222 Spanish specialists in otorhinolaryngology answered the questionnaire (10.29% of the sample surveyed).

CONCLUSIONS

The 50% of all respondents showed a medium-high knowledge about CI. Epidemiological data suggest that a high percentage of adults with postlocutive deafness and candidates for a CI are not referred for treatment. The lack of knowledge about the criteria for the indication of CI by otorhinolaryngology specialists may contribute to inadequate guidance of patients who are potential candidates for CI. The greatest shortcomings are found in the most emergency indications for a CI. Among otorhinolaryngology professionals, the greatest knowledge about CI is found in those who work in tertiary hospitals in the areas of otology and otoneurology, either in the public or private sector. This study suggests that training on CI should be increased for otorhinolaryngology professionals, especially for general otorhinolaryngologists.

Measuring Sound-Processor Threshold Levels for Pediatric Cochlear Implant Recipients Using Conditioned Play Audiometry via Telepractice

PURPOSE

This study evaluated the use of telepractice for measuring cochlear implant (CI) behavioral threshold (T) levels in children using conditioned play audiometry (CPA). The goals were to determine whether (a) T levels measured via telepractice were not significantly different from those obtained in person, (b) response probability differed between remote and in-person conditions, and (c) the remote visit required more time than the in-person condition.

METHOD

An ABBA design (A, in-person; B, remote) was split across 2 visits. Nineteen children aged 2.6-7.1 years participated. T levels were measured using CPA for 3 electrodes per session. A "hit" rate was calculated to determine whether the likelihood of obtaining responses differed between conditions. Test time was compared across conditions. A questionnaire was administered to assess parent/caregiver attitudes about telepractice.

RESULTS

Results indicated no significant difference in T levels between conditions. Hit rates were not significantly different between in-person and remote conditions (98% vs. 97%, respectively). Test time was similar between conditions. Questionnaire results revealed that 100% of caregivers would use telepractice for CI appointments either some or all of the time.

CONCLUSION

Telepractice is a viable option for routine pediatric programming appointments for children using CPA to set behavioral thresholds.

Paediatric Cochlear Implantation in Patients with Waardenburg Syndrome

OBJECTIVE

To analyse the benefit of cochlear implantation in young deaf children with Waardenburg syndrome (WS) compared to a reference group of young deaf children without additional disabilities.

METHOD

A retrospective study was conducted on children with WS who underwent cochlear implantation at the age of 2 years or younger. The post-operative results for speech perception (phonetically balanced standard Dutch consonant-vocal-consonant word lists) and language comprehension (the Reynell Developmental Language Scales, RDLS), expressed as a language quotient (LQ), were compared between the WS group and the reference group by using multiple linear regression analysis.

RESULTS

A total of 14 children were diagnosed with WS, and 6 of them had additional disabilities. The WS children were implanted at a mean age of 1.6 years and the 48 children of the reference group at a mean age of 1.3 years. The WS children had a mean phoneme score of 80% and a mean LQ of 0.74 at 3 years post-implantation, and these results were comparable to those of the reference group. Only the factor additional disabilities had a significant negative influence on auditory perception and language comprehension.

CONCLUSIONS

Children with WS performed similarly to the reference group in the present study, and these outcomes are in line with the previous literature. Although good counselling about additional disabilities concomitant to the syndrome is relevant, cochlear implantation is a good rehabilitation method for children with WS.

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.

New language outcome measures for Mandarin speaking children with hearing loss

Objective

The paper discusses recent evidence on the assessment of language outcomes in children with hearing loss acquiring oral language.

Methods

Research emphasizes that language tests must be specific enough to capture subtle deficits in vocabulary and grammar learning at different developmental ages. The Diagnostic Receptive and Expressive Assessment of Mandarin (DREAM) was carefully designed to be a comprehensive standardized Mandarin assessment normed in Mainland China.

Results

This paper summarizes the evidence-based item design process and validity and reliability results of DREAM. A pilot study reported here shows that DREAM provided detailed information about hearing impaired children's language abilities and can be used to aid intervention planning to maximize progress.

Conclusion

DREAM represents an example of translational science, transferring methods from empirical studies of language acquisition in research environments into applied domains such as assessment and intervention. Research on outcomes in China will advance significantly with the availability of evidence-based comprehensive language tests that measure a sufficient age range of skills, are normed on Mandarin speaking children in mainland China, and are designed to capture features central to Mandarin language acquisition.

A semi-supervised Support Vector Machine model for predicting the language outcomes following cochlear implantation based on pre-implant brain fMRI imaging

INTRODUCTION

We developed a machine learning model to predict whether or not a cochlear implant (CI) candidate will develop effective language skills within 2 years after the CI surgery by using the pre-implant brain fMRI data from the candidate.

METHODS

The language performance was measured 2 years after the CI surgery by the Clinical Evaluation of Language Fundamentals-Preschool, Second Edition (CELF-P2). Based on the CELF-P2 scores, the CI recipients were designated as either effective or ineffective CI users. For feature extraction from the fMRI data, we constructed contrast maps using the general linear model, and then utilized the Bag-of-Words (BoW) approach that we previously published to convert the contrast maps into feature vectors. We trained both supervised models and semi-supervised models to classify CI users as effective or ineffective.

RESULTS

Compared with the conventional feature extraction approach, which used each single voxel as a feature, our BoW approach gave rise to much better performance for the classification of effective versus ineffective CI users. The semi-supervised model with the feature set extracted by the BoW approach from the contrast of speech versus silence achieved a leave-one-out cross-validation AUC as high as 0.97. Recursive feature elimination unexpectedly revealed that two features were sufficient to provide highly accurate classification of effective versus ineffective CI users based on our current dataset.

CONCLUSION

We have validated the hypothesis that pre-implant cortical activation patterns revealed by fMRI during infancy correlate with language performance 2 years after cochlear implantation. The two brain regions highlighted by our classifier are potential biomarkers for the prediction of CI outcomes. Our study also demonstrated the superiority of the semi-supervised model over the supervised model. It is always worthwhile to try a semi-supervised model when unlabeled data are available.

Prevalence of various etiologies of hearing loss among cochlear implant recipients: Systematic review and meta-analysis

OBJECTIVE

To investigate the etiology of deafness in cochlear implanted children and to address the question whether there is a need for more thorough diagnostics, especially concerning genetics.

DESIGN

Systematic review. Four databases were searched for studies (year 2000-2014) on cochlear implanted children (n > 100). Studies were excluded if etiology had influenced their inclusion criteria. Eligibility and methodological quality were assessed independently by three authors. The studies' description of diagnostic evaluation was categorized in three groups.

STUDY SAMPLE

Sixteen studies were included (5069 children).

RESULTS

The most common etiological categories were 'Unknown' 40.3% (95% CI 32.8 to 48.0), 'Non-syndromic' 22.4% (95% CI 17.1 to 28.2), and 'Postnatal' 11.3% (95% CI 7.2 to 16.2). Studies published after 2006 had a lower proportion of 'Unknown' etiology 35.3% (95% CI 28.0 to 42.8) than older 45.5% (95% CI 31.0 to 60.4). Important information was missing from several studies: 11 (69%) studies did not provide detailed description on diagnostic evaluation of the etiology of deafness and had a higher proportion of 'Unknown' etiology.

CONCLUSIONS

In order to ensure a higher level of comparability in future studies, we recommend agreement upon an international standard of diagnostics and the introduction of an international standard for reporting etiology.

Factors influencing speech and language outcomes of children with early identified severe/profound hearing loss: Clinician-identified facilitators and barriers

PURPOSE

Early identification of severe/profound childhood hearing loss (HL) gives these children access to hearing devices and early intervention to facilitate improved speech and language outcomes. Predicting which infants will go on to achieve such outcomes remains difficult. This study describes clinician identified malleable and non-malleable factors that may influence speech and language outcomes for children with severe/profound HL.

METHOD

Semi-structured interviews were conducted with six experienced auditory verbal clinicians. A collective case study design was implemented. The interviews were transcribed and coded into themes using constant comparative analysis.

RESULT

Clinicians identified that, for children with severe/profound HL, early identification, early amplification and commencing auditory-verbal intervention under 6 months of age may facilitate child progress. Possible barriers were living in rural/remote areas, the clinicians' lack of experience and confidence in providing intervention for infants under age 6-months and belonging to a family with a culturally and linguistically diverse (CALD) background.

CONCLUSION

The results indicate that multiple factors need to be considered by clinicians working with children with HL and their families to determine how each child functions within their own environment and personal contexts, consistent with the International Classification of Functioning, Disability and Health (ICF) framework. Such an approach is likely to empower clinicians to carefully balance potential barriers to, and facilitators of, optimal speech and language outcomes for all children with HL.

Acoustic temporal modulation detection in normal-hearing and cochlear implanted listeners: effects of hearing mechanism and development

Temporal modulation detection ability matures over many years after birth and may be particularly sensitive to experience during this period. Profound hearing loss during early childhood might result in greater perceptual deficits than a similar loss beginning in adulthood. We tested this idea by measuring performance in temporal modulation detection in profoundly deaf children and adults fitted with cochlear implants (CIs). At least two independent variables could constrain temporal modulation detection performance in children with CIs: altered encoding of modulation information due to the CI-auditory nerve interface, and atypical development of central processing of sound information provided by CIs. The effect of altered encoding was investigated by testing subjects with one of two different hearing mechanisms (normal hearing vs. CI) and the effect of atypical development was studied by testing two different age groups. All subjects were tested for their ability to detect acoustic temporal modulations of sound amplitude. A comparison of the slope, or cutoff frequency, of the temporal modulation transfer functions (TMTFs) among the four subject groups revealed that temporal resolution was mainly constrained by hearing mechanism: normal-hearing listeners could detect smaller amplitude modulations at high modulation frequencies than CI users. In contrast, a comparison of the height of the TMTFs revealed a significant interaction between hearing mechanism and age group on overall sensitivity to temporal modulation: sensitivity was significantly poorer in children with CIs, relative to the other three groups. Results suggest that there is an age-specific vulnerability of intensity discrimination or non-sensory factors, which subsequently affects sensitivity to temporal modulation in prelingually deaf children who use CIs.

Results in cochlear implanted children before 5 years of age. a long term follow up

OBJECTIVE

To assess the hearing threshold and linguistic results of cochlear implanted children aged 10 months to 5 years, when they reached the age of 12. We studied the benefits of sequential bilateral implantation.

METHOD AND RESULTS

This is an observational, descriptive, transversal study comprising 57 cochlear implanted subjects. We performed a free field tonal audiometry at 65dB SPL, speech tests and sentences in quiet and noise (SNR+10) tests. The Objective and Criterial Language Battery (BLOC) was used to assess linguistic competence, in its screening version.

RESULTS

Children implanted under the age of 2 and with inter-implant period less than or equal to 4 years reached better statistically significant results in disyllabic and sentences with and without noise (p=0.006) tests and in the disyllabic test with noise (p=0.045) (the hardest speech test). This suggests the acquisition of binaurality, as opposed to children implanted after this age, with inter-implant period longer than 4 years, who do not reach the same performance levels.

RESULTS

of language development in the group implanted at ages 10 months to 2 years are better with respect to implanted children at ages 3-5 (<0.05) in both unilateral and bilateral implanted children in relation to the age of implantation.

CONCLUSION

Children with pre-lingual deafness implanted before the age of 2, when they are 12 years old obtain more benefits in their language development and in their linguistic competence than children implanted after this age. The audiology results are better in children implanted bilaterally under the age of 2.

The development of auditory perception in children after auditory brainstem implantation

Auditory brainstem implants (ABIs) can provide useful auditory perception and language development in deaf children who are not able to use a cochlear implant (CI). We prospectively followed up a consecutive group of 64 deaf children up to 12 years following ABI surgery. The etiology of deafness in these children was: cochlear nerve aplasia in 49, auditory neuropathy in 1, cochlear malformations in 8, bilateral cochlear postmeningitic ossification in 3, neurofibromatosis type 2 in 2, and bilateral cochlear fractures due to a head injury in 1. Thirty-five children had other congenital nonauditory disabilities. Twenty-two children had previous CIs with no benefit. Fifty-eight children were fitted with the Cochlear 24 ABI device and 6 with the MedEl ABI device, and all children followed the same rehabilitation program. Auditory perceptual abilities were evaluated on the Categories of Auditory Performance (CAP) scale. No child was lost to follow-up, and there were no exclusions from the study. All children showed significant improvement in auditory perception with implant experience. Seven children (11%) were able to achieve the highest score on the CAP test; they were able to converse on the telephone within 3 years of implantation. Twenty children (31.3%) achieved open set speech recognition (CAP score of 5 or greater) and 30 (46.9%) achieved a CAP level of 4 or greater. Of the 29 children without nonauditory disabilities, 18 (62%) achieved a CAP score of 5 or greater with the ABI. All children showed continued improvements in auditory skills over time. The long-term results of ABI surgery reveal significant auditory benefit in most children, and open set auditory recognition in many.

Combining growth curves when a longitudinal study switches measurement tools

When longitudinal studies are performed to investigate the growth of traits in children, the measurement tool being used to quantify the trait may need to change as the subjects' age throughout the study. Changing the measurement tool at some point in the longitudinal study makes the analysis of that growth challenging which, in turn, makes it difficult to determine what other factors influence the growth rate. We developed a Bayesian hierarchical modeling framework that relates the growth curves per individual for each of the different measurement tools and allows for covariates to influence the shapes of the curves by borrowing strength across curves. The method is motivated by and demonstrated by speech perception outcome measurements of children who were implanted with cochlear implants. Researchers are interested in assessing the impact of age at implantation and comparing the growth rates of children who are implanted under the age of two versus those implanted between the ages of two and four.

Communication development in children who receive a cochlear implant by 12 months of age

OBJECTIVE

Describe the long-term benefits of early cochlear implantation. Provide a comprehensive description of outcomes, including: language, speech production, and speech perception. Compare the communication outcomes for the early implanted children to those of normally hearing children and children who received a cochlear implant at a comparatively older age.

METHOD

Retrospective review of the communication development of 35 children implanted between 6 and 12 months of age and 85 children implanted between 13 and 24 months of age. Audiologic assessments included unaided and aided audiograms, auditory brainstem response (ABR), auditory steady state response (ASSR), and otoacoustic emissons (OAEs). Formal language, speech production, and speech perception measures were administered, preimplant and at 1, 2, 3, and 5 years postimplant.

RESULTS

The children who received their cochlear implant by 12 months of age demonstrated language growth rates equivalent to their normally hearing peers and achieved age appropriate receptive language scores 3 years postimplant. The children who received their cochlear implant between 13 and 24 months demonstrated a significant language delay at 3 years postimplant. Speech production development followed a similar pattern to that of normal-hearing children, although was delayed, for both groups of children. Mean open-set speech perception scores were comparable with previous reports for children and adults who use cochlear implants.

CONCLUSION

Children implanted by 12 months of age demonstrate better language development compared with children who receive their cochlear implant between 13 and 24 months. This supports the provision of a cochlear implant within the first year of life to enhance the likelihood that a child with severe-to-profound hearing impairment will commence elementary school with age-appropriate language skills.

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.