Benefits and risks related to cochlear implantation for children with residual hearing: a systematic review

OBJECTIVE

This study aimed to synthesise information concerning the potential benefits and risks related to cochlear implants (CIs) versus hearing aids (HAs) in children with residual hearing.

DESIGN

A systematic review of articles published from January 2003 to January 2019 was conducted.

STUDY SAMPLE

Our review included studies that compared the benefits and risks of CIs versus HAs in children (≤18 years old) with residual hearing. A total of 3265 citations were identified; 8 studies met inclusion criteria.

RESULTS

Children with CIs showed significantly better speech perception scores post-CI than pre-CI. There was limited evidence related to improvement in everyday auditory performance, and the results showed non-significant improvement in speech intelligibility. One study on social-emotional functioning suggested benefits from CIs. In four studies, 37.2% (16/43) of children showed loss of residual hearing and 14.0% (8/57) had discontinued or limited use of their device.

CONCLUSIONS

Children with CIs showed improvement in speech perception outcomes compared to those with HAs. However, due to the limited number of studies and information to guide decision-making related to other areas of development, it will be important to conduct further research of both benefits and risks of CIs in this specific population to facilitate decision-making.

Determining cochlear implant candidacy in children with residual hearing: A scoping review

OBJECTIVES

The purpose of this review was to summarize what is known about criteria, assessments, and recommendations for evaluating cochlear implant (CI) candidacy in children with residual hearing.

METHODS

Peer-reviewed studies were identified through a systematic search in five electronic databases. Articles were screened and assessed for eligibility. From the eligible studies, data were extracted to summarize and present a narrative synthesis of the findings.

RESULTS

A total of seven articles (two reviews and five primary studies) were included in the final analysis. Hearing levels better than the moderately severe to severe range (65-90 dB HL) tend to be supported as audiological candidacy criteria for pediatric CI. Recommendations for candidacy consideration based on audiologic thresholds range from 65 to 80 dB Hl pure-tone average as the lower boundary. Our review did not identify any specific assessment protocols. However, additional decision-making considerations related to borderline hearing loss configurations and assessment tools (the Speech Intelligibility Index and the Pediatric Minimum Speech Test Battery) were identified. Supplementary assessment considerations were also reported.

CONCLUSION

There is limited information regarding specific assessment protocols for children with residual hearing. The literature is primarily focused on guidelines related to audiologic criteria, although it is widely recommended that other areas of functioning should also be considered. Most recommendations appear to be based on expert opinion, clinical expertise, and evidence from overall pediatric CI outcomes rather than empirical evidence targeting children with residual hearing. There is an ongoing need for research to further develop protocols and tools that can assist clinicians and families in making cochlear implantation decisions for children with residual hearing.

Acceptance and Benefit of Electroacoustic Stimulation in Children

OBJECTIVE

Children with high-frequency severe-to-profound hearing loss and low-frequency residual hearing who do not derive significant benefit from hearing aids are now being considered for cochlear implantation. Previous research shows that hearing preservation is possible and may be desirable for the use of electroacoustic stimulation (EAS) in adults, but this topic remains underexplored in children. The goal of this study was to explore factors relating to hearing preservation, acceptance, and benefits of EAS for children.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary academic medical center.

PATIENTS

Forty children (48 ears) with preoperative low-frequency pure-tone averages of 75 dB HL or less at 250 and 500 Hz (n = 48).

INTERVENTION

All patients underwent cochlear implantation with a standard-length electrode.

MAIN OUTCOME MEASURE

Low-frequency audiometric thresholds, speech perception, and EAS usage were measured at initial stimulation, and 3 and 12 months postoperatively. Outcomes were compared between children with and without hearing preservation, and between EAS users and nonusers.

RESULTS

Hearing was preserved at similar rates as adults but worse for children with an enlarged vestibular aqueduct. Fewer than half of children who qualified to use EAS chose to do so, citing a variety of audiologic and nonaudiologic reasons. No differences were detected in speech perception scores across the groups for words, sentences, or sentences in noise tests.

CONCLUSIONS

Neither hearing preservation nor EAS use resulted in superior speech perception in children with preoperative residual hearing; rather, all children performed well after implantation.

Cochlear Implant Decision Making for Children With Residual Hearing: Perspectives of Practitioners

PURPOSE

Cochlear implants (CIs) are increasingly considered for children with residual hearing who benefit from hearing aids (HAs). However, the decision-making process for families of these children and for practitioners is particularly challenging because there is no clear audiological cut point for CI candidacy. This study aimed to understand Canadian practitioners' perspectives of the CI decision-making process and how they guide families of children with residual hearing.

METHOD

Semistructured interviews were conducted with a total of 17 practitioners through four focus groups and one individual interview. Interviews were transcribed verbatim, and a thematic analysis was carried out.

RESULTS

Data were organized into five broad domains: candidacy issues for children with residual hearing, practitioners' roles in decision support, additional considerations affecting decision making, factors facilitating decision making, and practitioners' needs.

CONCLUSIONS

This study found that practitioners' confidence in determining candidacy and supporting parents has increased due to their experiences with positive outcomes for these children. Practitioners indicated that there was a need for more research to guide the decision-making process.

Efficacy of cochlear implants in children with borderline hearing who have already achieved significant language development with hearing aids

There are still debates about timing and effectiveness of cochlear implants (CI) in pediatric subjects with significant residual hearing who do not belong to traditional indication of CI. In this study, we aimed to investigate the outcomes of CI, specifically on improvement of pronunciation, among hearing-impaired children already with a substantial degree of language skills as evaluated by Categories of Auditory Perception (CAP) scores or sentence score. Our cohort comprised pediatric CI recipients from July 2018 through October 2020. Among them, cases with CAP scores of 5 or 6 preoperatively were defined as "borderline cases". We investigated prevalence and etiologies, and compared speech evaluation data preoperatively and postoperatively at three time points (3, 6 and 9-12 months after implantation). Among 86 pediatric CI recipients, 13 subjects (15.12%) had language development that reached CAP scores of 5 or 6 before implantation. Postoperative speech evaluation data 6 months after implantation revealed significant improvement of pronunciation (Urimal Test of Articulation and Phonation scores: UTAP), Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and word perception scores, but not of CAP and sentence perception scores. Notably, the significant improvement of pronunciation based on UTAP scores outstripped that of other speech parameters and this continued steadily up to one-year postoperatively. The result of the study serves as evidence for what to expect from cochlear implantation in hearing-impaired children who have already achieved a substantial degree of language development in terms of CAP scores or sentence perception scores, preoperatively.

The Limitations of FDA Criteria: Inconsistencies with Clinical Practice, Findings, and Adult Criteria as a Barrier to Pediatric Implantation

Children require greater access to sound than adults as they are learning to communicate using hearing and spoken language. Yet when it comes to cochlear implant candidacy, currently approved Food and Drug Administration (FDA) criteria for adults are much less restrictive than those for children, allowing for greater levels of residual hearing and aided speech recognition in adults. Cochlear implant guidelines for children have changed very little in the 30 years since cochlear implants have been approved for pediatrics, and this lack of change has proven to be a barrier to implantation. Using evidence-based practice, centers have been providing off-label implantation for children who fall outside of current FDA criteria, including children with more residual hearing, children with single-side deafness younger than 5 years, and infants with bilateral profound loss younger than 9 months. The purpose of this article is to outline how these restrictions impede access to implants for children and describe the evidence supporting cochlear implantation in children who fall outside of current criteria.

Expansion of Audiologic Criteria for Pediatric Cochlear Implantation

In 2020, the lower age limit for pediatric cochlear implant candidacy was lowered from 12 to 9 months of age. However, audiometric-based criteria for pediatric cochlear implant candidacy have remained unchanged for more than 20 years, requiring bilateral profound sensorineural hearing loss for children less than 2 years and bilateral severe-to-profound sensorineural hearing loss for children 2 years and older. Despite the static audiometric criteria, there is an increasing literature base demonstrating significant benefits for pediatric cochlear implant recipients who exceed current Food and Drug Administration-labeled indications for cochlear implantation.

Feasibility of Day Surgery for Cochlear Implantation under Conscious Sedation with Same-Day Fitting

OBJECTIVES

To evaluate the feasibility of performing cochlear implantation under conscious sedation (CS) as day surgery with same-day fitting.

MATERIALS AND METHODS

All patients underwent cochlear implantation under CS between November 2017 and April 2018. The data collected included demographic information, preoperative clinical characteristics, surgical details, postoperative fitting information, and side effects, if any.

RESULTS

Nine patients had 11 cochlear implants (CIs) placed under CS (2 patients received bilateral CIs). One patient's data were excluded from the audiological results because conversion to general anesthesia (GA) was necessary. One patient (11%) vomited just before the end of the procedure. Seven patients had uneventful procedures. Eight (88%) patients were discharged home the same day. There was a statistically significant difference in recovery time between the CS group and the GA group (t=-2.26, df=12, p<0.05). In the CS group, there was no statistically significant change in the maximum comfortable loudness level for all electrodes from the day of the surgery to the following day. However, there was a statistically significant difference in the threshold levels of all electrodes from the day of the surgery to the following day (Z=-2.04, N=120, p<0.05). Further analysis revealed a statistically significant difference in the four most apical electrodes (Z=-3.496, N=40, p<0.0001), but not in the middle or basal electrodes.

CONCLUSION

Cochlear implantation can be performed under CS with careful patient selection. This approach facilitates same-day fitting and day surgery by minimizing comorbidity.

Outcomes of Cochlear Implantation in Patients with Pendred syndrome: A Systematic Review and Narrative Synthesis

Establish outcomes following cochlear implantation (CI) in patients with Pendred syndrome. Systematic review and narrative synthesis. Databases searched: Medline, Pubmed, Embase, Web of Science, Cochrane Collection and ClinicalTrials.gov. No limits placed on language or year of publication. Review conducted in accordance with the PRISMA statement. Searches identified 251 abstracts and 242 full texts. Of these, 22 studies met inclusion criteria reporting outcomes in 231 patients with at least 234 implants. Hearing outcomes were generally good with patients experiencing useful functional improvement. A total of 46 minor complications were reported in 78 cases. The methodological quality of included studies was modest, predominantly consisting of case reports and non-controlled case series with small numbers of patients. All studies were OCEBM grade III-IV. Hearing outcomes following CI in Pendred syndrome are generally good with useful functional improvement. However, outcomes reported in published studies lack long term follow up.

A Scoping Review of Studies Comparing Outcomes for Children With Severe Hearing Loss Using Hearing Aids to Children With Cochlear Implants

OBJECTIVES

Clinical practice regarding children's candidature for cochlear implantation varies internationally, albeit with a recent global trend toward implanting children with more residual hearing than in the past. The provision of either hearing aids or cochlear implants can influence a wide range of children's outcomes. However, guidance on eligibility and suitability for implantation is often based on a small number of studies and a limited range of speech perception measures. No recent reviews have catalogued what is known about comparative outcomes for children with severe hearing-loss using hearing aids to children using cochlear implants. This article describes the findings of a scoping review that addressed the question "What research has been conducted comparing cochlear implant outcomes to outcomes in children using hearing aids with severe hearing-loss in the better-hearing ear?" The first objective was to catalogue the characteristics of studies pertinent to these children's candidature for cochlear implantation, to inform families, clinicians, researchers, and policy-makers. The second objective was to identify gaps in the evidence base, to inform future research projects and identify opportunities for evidence synthesis.

DESIGN

We included studies comparing separate groups of children using hearing aids to those using cochlear implants and also repeated measures studies comparing outcomes of children with severe hearing loss before and after cochlear implantation. We included any outcomes that might feasibly be influenced by the provision of hearing aids or cochlear implants. We searched the electronic databases Medline, PubMed, and CINAHL, for peer-reviewed journal articles with full-texts written in English, published from July 2007 to October 2019. The scoping methodology followed the approach recommended by the Joanna Briggs Institute regarding study selection, data extraction, and data presentation.

RESULTS

Twenty-one eligible studies were identified, conducted across 11 countries. The majority of children studied had either congenital or prelingual hearing loss, with typical cognitive function, experience of spoken language, and most implanted children used one implant. Speech and language development and speech perception were the most frequently assessed outcomes. However, some aspects of these outcomes were sparsely represented including voice, communication and pragmatic skills, and speech perception in complex background noise. Two studies compared literacy, two sound localization, one quality of life, and one psychosocial outcomes. None compared educational attainment, listening fatigue, balance, tinnitus, or music perception.

CONCLUSIONS

This scoping review provides a summary of the literature regarding comparative outcomes of children with severe hearing-loss using acoustic hearing aids and children using cochlear implants. Notable gaps in knowledge that could be addressed in future research includes children's quality of life, educational attainment, and complex listening and language outcomes, such as word and sentence understanding in background noise, spatial listening, communication and pragmatic skills. Clinician awareness of this sparse evidence base is important when making management decisions for children with more residual hearing than traditional implant candidates. This review also provides direction for researchers wishing to strengthen the evidence base upon which clinical decisions can be made.

The Effects of GJB2 or SLC26A4 Gene Mutations on Neural Response of the Electrically Stimulated Auditory Nerve in Children

OBJECTIVES

This study aimed to (1) investigate the effect of GJB2 and SLC26A4 gene mutations on auditory nerve function in pediatric cochlear implant users and (2) compare their results with those measured in implanted children with idiopathic hearing loss.

DESIGN

Participants included 20 children with biallelic GJB2 mutations, 16 children with biallelic SLC26A4 mutations, and 19 children with idiopathic hearing loss. All subjects except for two in the SLC26A4 group had concurrent Mondini malformation and enlarged vestibular aqueduct. All subjects used Cochlear Nucleus devices in their test ears. For each subject, electrophysiological measures of the electrically evoked compound action potential (eCAP) were recorded using both anodic- and cathodic-leading biphasic pulses. Dependent variables (DVs) of interest included slope of eCAP input/output (I/O) function, the eCAP threshold, and eCAP amplitude measured at the maximum comfortable level (C level) of the anodic-leading stimulus (i.e., the anodic C level). Slopes of eCAP I/O functions were estimated using statistical modeling with a linear regression function. These DVs were measured at three electrode locations across the electrode array. Generalized linear mixed effect models were used to evaluate the effects of study group, stimulus polarity, and electrode location on each DV.

RESULTS

Steeper slopes of eCAP I/O function, lower eCAP thresholds, and larger eCAP amplitude at the anodic C level were measured for the anodic-leading stimulus compared with the cathodic-leading stimulus in all subject groups. Children with GJB2 mutations showed steeper slopes of eCAP I/O function and larger eCAP amplitudes at the anodic C level than children with SLC26A4 mutations and children with idiopathic hearing loss for both the anodic- and cathodic-leading stimuli. In addition, children with GJB2 mutations showed a smaller increase in eCAP amplitude when the stimulus changed from the cathodic-leading pulse to the anodic-leading pulse (i.e., smaller polarity effect) than children with idiopathic hearing loss. There was no statistically significant difference in slope of eCAP I/O function, eCAP amplitude at the anodic C level, or the size of polarity effect on all three DVs between children with SLC26A4 mutations and children with idiopathic hearing loss. These results suggested that better auditory nerve function was associated with GJB2 but not with SLC26A4 mutations when compared with idiopathic hearing loss. In addition, significant effects of electrode location were observed for slope of eCAP I/O function and the eCAP threshold.

CONCLUSIONS

GJB2 and SLC26A4 gene mutations did not alter polarity sensitivity of auditory nerve fibers to electrical stimulation. The anodic-leading stimulus was generally more effective in activating auditory nerve fibers than the cathodic-leading stimulus, despite the presence of GJB2 or SLC26A4 mutations. Patients with GJB2 mutations appeared to have better functional status of the auditory nerve than patients with SLC26A4 mutations who had concurrent Mondini malformation and enlarged vestibular aqueduct and patients with idiopathic hearing loss.

Clinical characteristics and outcomes of children with cochlear implants who had preoperative residual hearing

OBJECTIVE

Cochlear implants (CI) candidacy criteria have expanded to include children with more residual hearing. This study explored the clinical profiles and outcomes of children with CIs who had preoperative residual hearing in at least one ear.

DESIGN

A retrospective chart review was conducted to collect clinical characteristics and speech perception data. Pre- and post-CI auditory and speech perception data were analysed using a modified version of the Pediatric Ranked Order Speech Perception (PROSPER) score.

STUDY SAMPLE

This study included all children with residual hearing who received CIs in one Canadian paediatric centre from 1992 to 2018.

RESULTS

A total of 100 of 389 (25.7%) children with CIs had residual hearing (median 77.6 dB HL, better ear). The proportion of children with residual hearing increased from 1992 to 2018. Children who had auditory behaviour and speech perception tests (n = 83) showed higher modified PROSPER scores post-CI compared to pre-CI. Phonologically Balanced Kindergarten (PBK) test scores were available for 71 children post-CI; 81.7% (58/71) of children achieved > 80% on the PBK.

CONCLUSIONS

One in four children who received CIs had residual hearing, and most of them had severe hearing loss at pre-CI. These children showed a high level of speech perception with CIs.

Delaying Cochlear Implantation Impacts Postoperative Speech Perception of Nontraditional Pediatric Candidates

INTRODUCTION

As pediatric cochlear implant (CI) candidacy expands, children with greater degrees of residual hearing are receiving CIs. These nontraditional candidates have audiometric thresholds that meet adult manufacturer labeling but are better than current pediatric guidelines allow. The purpose of this study was to determine the impact of delayed cochlear implantation on speech perception in nontraditional pediatric CI recipients.

METHODS

Pediatric CI recipients with a history of progressive hearing loss and a preoperative 4-frequency pure-tone average of ≤75 dB HL at the time of implantation were considered for this retrospective study. Preoperative serial audiograms and word recognition scores were reviewed, and a method was created to establish a date when each individual ear 1st met nontraditional candidacy. The length of time between the date of candidacy and implantation was calculated and defined as the "delay time." A multiple linear regression investigated delay time, age at surgery, surgery type (1st vs. 2nd side), and array type as predictive factors of maximum postoperative Consonant-Nucleus-Consonant (CNC) word scores. A one-way ANCOVA was performed comparing the postoperative CNC scores between subjects grouped by delay time.

RESULTS

A significant regression was found (F(4, 38) = 5.167, p = 0.002, R2 = 0.353). Both age at implantation (p = 0.023) and delay time (p = 0.002) predicted CNC word scores. Longer delay time was associated with poorer word recognition scores, while older age at implantation correlated with higher CNC word scores in this progressive hearing loss group. A significant difference was noted between subjects implanted with <1 year of delay and those with 3 or more years of delay (p = 0.003). All ears implanted within a year of candidacy achieved word recognition abilities that are generally accepted as above average (M = 84.91).

CONCLUSION

CI candidacy for adults has evolved to allow for greater degrees of residual hearing, while audiometric guidelines for children have not changed since 2000. Our findings suggest that delay of cochlear implantation, even for children with significant levels of residual hearing, leads to poorer outcomes. Modified candidacy guidelines for children should be established to expedite referral to multidisciplinary CI teams and minimize delays in this population.

Effect of Cochlear Implantation on Hearing Fluctuation in Patients with Biallelic SLC26A4 Variants

INTRODUCTION

Fluctuating hearing loss is a distinctive feature caused by SLC26A4 variants. We investigated whether cochlear implantation had protective or deleterious effect on hearing fluctuation in patients with biallelic SLC26A4 variants.

METHODS

Patients with biallelic SLC26A4 variants (N = 16; age = 10.24 ± 9.20 years) who had unilateral cochlear implantation and consecutive postsurgical, bilateral pure-tone audiograms more than 3 times were selected. We retrospectively reviewed the patients' medical records from 2008 to 2019 obtained from a tertiary medical center and used the auditory threshold change (Shift) over time as a marker of hearing fluctuation. Fluctuation events were counted, and the Shift of the implanted and contralateral ears was compared using logistic regression with a generalized estimating equation and linear mixed model. A total of 178 values were included.

RESULTS

The odds of fluctuating hearing frequency were 11.185-fold higher in the unimplanted ears than in the implanted ears postoperatively (p = 0.001). The extent of fluctuation at 250 and 500 Hz was also significantly lower in the implanted ears than in the unimplanted ears after adjusting for every other effect (p = 0.003 and p < 0.001, respectively). Notably, higher residual hearing was rather associated with lesser fluctuation in frequency and the extent of fluctuation at 500 Hz, indicating residual hearing function is not the positive predictor for hearing fluctuation.

CONCLUSION

In patients with biallelic SLC26A4 variants, cochlear implantation may reduce the frequency and extent of hearing fluctuations.

Treating the Individual Ear in Children: Results of Cochlear Implantation in Children With Asymmetric Sensory Hearing Loss

OBJECTIVE

Determine speech outcomes of children undergoing cochlear implantation with severe-to-profound hearing loss in the implanted ear and moderate or better hearing loss in nonimplanted ear.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Forty-nine children with severe-to-profound hearing loss in the ear to be implanted (pure-tone average), and no worse than moderate hearing loss in the nonimplant ear.

INTERVENTION

Subjects underwent cochlear implantation from 2007 and 2017 in the ear with severe-to-profound hearing loss.

MAIN OUTCOME MEASURES

Consonant Nucleus Consonant or Phonetically Balanced Kindergarten word scores pre- and postoperatively were compared in both the implanted ear and binaural setting. Comparisons were made between Phonetically Balanced Kindergarten scores pre- and postoperatively or Consonant Nucleus Consonant scores pre- and postoperatively.

RESULTS

The average pure-tone average for the implant ear was 92 ± 13 dB HL and 55 ± 12 dB HL in the nonimplant ear. Word scores for the implant ear increased an average of 58 (±27) % following cochlear implantation at 12 months and 62 (±20) % at 24 months. Binaural best-aided word scores increased an average of 36 (±29) % at 12 months and 49 (±24) % at 24 months.

CONCLUSION

Children with asymmetric sensory hearing loss should have each ear treated individually as significant benefits can be gained not only in the implanted ear, but also in binaural hearing.

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

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

Children With Single-Sided Deafness Use Their Cochlear Implant

OBJECTIVES

To assess acceptance of a cochlear implant (CI) by children with single-sided deafness (SSD) as measured by duration of CI use across daily listening environments.

DESIGN

Datalogs for 7 children aged 1.1 to 14.5 years (mean ± SD: 5.9 ± 5.9 years old), who had SSD and were implanted in their deaf ear, were anonymized and extracted from their CI processors. Data for all available follow-up clinical appointments were included, ranging from two to six visits. Measures calculated from each datalog included frequency and duration of time the coil disconnected from the internal device, average daily CI use, and both duration (hr/day) and percentage of CI use (% daily use) in different intensity ranges and environment types. Linear mixed effects regression analyses were used to evaluate the relationships between CI experience, daily CI use, frequency of coil-offs, and duration of coil-off time. Nonlinear regression analyses were used to evaluate CI use with age in different acoustic environments.

RESULTS

Children with SSD used their CI on average 7.4 hr/day. Older children used their CI for longer periods of the day than younger children. Longitudinal data indicated consistent CI use from the date of CI activation. Frequency of coil-offs reduced with CI experience, but did not significantly contribute to hours of coil-off time. Children used their CI longest in environments that were moderately loud (50 to 70 dB A) and classified as containing speech-in-noise. Preschoolers tended to spend less time in quiet but more time in music than infants/toddlers and adolescents.

CONCLUSIONS

Children with SSD consistently use their CI upon activation in a variety of environments commonly experienced by children. CI use in children with SSD resembles reported bilateral hearing aid use in children but is longer than reported hearing aid use in children with less severe unilateral hearing loss, suggesting that (1) the normal-hearing ear did not detract from consistent CI use; and (2) a greater asymmetry between ears presents a significant impairment that may facilitate device use to access bilateral sound.

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.

Criteria versus guidelines: Are we doing the best for our paediatric patients?

The National Institute for Health and Care Excellence guidance for the provision of cochlear implants (NICE Technology Appraisal Guidance 166. Cochlear implants for children and adults with severe to profound deafness. 2009. National Health Service National Institute for Health and Clinical Excellence.) are used to develop candidacy criteria by public health funding bodies within the UK. Often the guidance is interpreted as strict 'criteria' whereby clinicians adhere to specific audiometric thresholds without accounting for the acceptable range of performance on individual tests or a child's functional development. In this paper four clinical paediatric case studies are described from two cochlear implant centres which serve to illustrate difficulties in applying NICE guidance as strict criteria. These are presented in the context of recommending more flexible interpretation based on the content of the current guidance along with considerations of circumstances where NICE guidance might be adapted to optimise use of cochlear implant technology within a national framework.