Functional outcome of sequential bilateral cochlear implantation in young children: 36 months postoperative results

Children using a unilateral cochlear implant and contralateral hearing aid: bimodal hearing outcomes when one ear is outside the UK (NICE 2009) audiological criteria for cochlear implantation - a single site case-control study

INTRODUCTION

In the new revised National Institute for Health & Care Excellence (NICE, TA566, 2019) guidelines for cochlear implantation (CI) have clearly stipulated that the hearing loss must be bilateral. Prior to this revision, children and young people (CYP) with asymmetrical thresholds have been considered for unilateral CI when one ear was in audiological criteria. Children with asymmetrical hearing loss represent an important cohort of potential CI candidates, who will continue to be prevented from benefiting from CI unless evidence is produced to support implantation and maximise subsequent benefit.The aim of this study is to evaluate the 'real-life' hearing performance in a group of children who have received a unilateral CI and who have hearing thresholds in the contralateral ear that are outside the current UK NICE 2019 audiological criteria for CI. The contralateral ear will be aided using a conventional hearing aid (HA). The outcomes from this 'bimodal' group will be compared with a group of children who have received bilateral CI, and a group of children using bilateral HA, to extend the current knowledge about the different performance levels between bilateral CI, bilateral HA and bimodal hearing in CYP.

METHODS AND ANALYSIS

Thirty CYP aged 6-17 years old, 10 bimodal users, 10 bilateral HA users and 10 bilateral cochlear implant users will be subjected to a test battery consisting of: (1) spatial release from masking, (2) complex pitch direction discrimination, (3) melodic identification, (4) perception of prosodic features in speech and (5) TEN test. Subjects will be tested in their optimal device modality. Standard demographic and hearing health information will be collected. In the absence of comparable published data to power the study, sample size was determined on pragmatic grounds. Tests are exploratory and for hypothesis generating purposes. Therefore, the standard criterion of p<0.05 will be used.

ETHICS AND DISSEMINATION

This has been approved by the Health Research Authority and NHS REC within the UK (22/EM/0104). Industry funding was secured via a competitive researcher-led grant application process. Trial results will be subject to publication according to the definition of the outcome presented in this protocol.

Speech Perception of Second Cochlear Implant after 6 Years of Age in Prelingually Deaf Children

Sequential bilateral cochlear implantation in children becomes less effective as the inter-implant interval increases. However, the cause of this and the age at which speech perception becomes impossible are unclear. We examined the cases of 11 prelingually deaf children who underwent unilateral cochlear implantation at our hospitals before the age of 5 years old, followed by a second implantation procedure on the contralateral side when they were aged ≥ 6 years old (6-12 years old). The subjects' hearing thresholds and speech discrimination scores for the second cochlear implant were evaluated at 3 postoperative months and 1-7 years. All of the subjects demonstrated improvements in their hearing thresholds to a mean of 30 dB HL at 1 year. Regarding speech perception, one patient (a 12-year-old), who had developed bilateral hearing loss at 30 months of age after contracting mumps, demonstrated a 90% improvement in his speech discrimination score at 1 year. However, among the other congenitally deaf children, there were two patients whose speech discrimination scores had improved by ≥ 80% at > 4 postoperative years. The congenitally deaf children exhibited poor speech perception despite showing improved hearing thresholds in the ears that received second cochlear implants. Assuming that the auditory pathway beyond the superior olivary complex remained functional, the reduced speech perception abilities associated with the second cochlear implants may have been attributable to the loss of the spiral ganglion and cochlear nucleus cells due to a lack of auditory input since birth.

Different modes of cochlear implantation in children: a comparative study on hearing and speech rehabilitation effects

Objective

To study the effectiveness of unilateral cochlear implantation, binaural-bimodal hearing devices, and bilateral cochlear implantation in children with inner-ear malformation.

Methods

This study comprised 261 patients who were allocated to inner-ear malformation or control groups. Twenty-four months after surgery, aided sound-field thresholds were tested, and the Meaningful Auditory Integration Scale, Infant-Toddler Meaningful Auditory Integration Scale, Meaningful Use of Speech Scale, Categories of Auditory Performance scale and Speech Intelligibility Rating test were completed.

Results

Aided sound-field thresholds were significantly better for bilateral cochlear implantation patients than for unilateral cochlear implantation or binaural-bimodal hearing device patients. There was no significant difference in Meaningful Auditory Integration Scale, Infant-Toddler Meaningful Auditory Integration Scale, or Categories of Auditory Performance scores among the three groups. The binaural-bimodal hearing device patients outperformed unilateral cochlear implantation patients on both Meaningful Use of Speech Scale and Speech Intelligibility Rating scores. No statistical difference was observed between the two subgroups.

Conclusion

Children who received bilateral cochlear implants have the best auditory awareness in a quiet environment. Children with binaural-bimodal hearing devices have better voice control and verbal skills than unilateral cochlear implantation patients, and people are more likely to understand them. Children with inner-ear malformations benefit from cochlear implantation.

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.

Sequential bilateral cochlear implant: results in children and adolescents

Introduction

The use of the bilateral cochlear implants can promote the symmetrical development of the central auditory pathways, thus benefiting the development of auditory abilities and improving sound localization and the ability of auditory speech perception in situations of competitive noise.

Objective

To evaluate the ability of speech perception in children and adolescents using sequential bilateral cochlear implants, considering the association of these variables: age at surgery, time of device use and interval between surgeries.

Methods

A total of 14 individuals between 10 and 16 years of age, who demonstrated surgical indication for the use of sequential bilateral cochlear implants as intervention in the auditory habilitation process, were assessed. The speech perception ability was assessed through sentence lists constructed in the Portuguese language, presented in two situations: in silence, with fixed intensity of 60 dB SPL, and in competitive noise, with a signal-to-noise ratio of +15 dB. The evaluation was performed under the following conditions: unilateral with the first activated cochlear implant, unilateral with the second activated cochlear implant and bilateral with both devices activated.

Results

The results of the speech perception tests showed better performance in both silence and in noise for the bilateral cochlear implant condition when compared to the 1st cochlear implant and the 2nd cochlear implant alone. A worse result of speech perception was found using the 2nd cochlear implant alone. No statistically significant correlation was found between age at the surgical procedure, interval between surgeries and the time of use of the 2nd cochlear implant, and the auditory speech perception performance for all assessed conditions. The use of a hearing aid prior to the 2nd cochlear implant resulted in benefits for auditory speech perception with the 2nd cochlear implant, both in silence and in noise.

Conclusion

The bilateral cochlear implant provided better speech perception in silence and in noise situations when compared to the unilateral cochlear implant, regardless of the interval between surgeries, age at the surgical procedure and the time of use of the 2nd cochlear implant. Speech perception with the 1st cochlear implant was significantly better than with the 2nd cochlear implant, both in silence and in noise. The use of the hearing aid prior to the 2nd cochlear implant influenced speech perception performance with the 2nd cochlear implant, both in silence and in noise.

United Kingdom national paediatric bilateral project: Results of professional rating scales and parent questionnaires

OBJECTIVES

This fourteen-centre project used professional rating scales and parent questionnaires to assess longitudinal outcomes in a large non-selected population of children receiving simultaneous and sequential bilateral cochlear implants.

METHODS

This was an observational non-randomized service evaluation. Data were collected at four time points: before bilateral cochlear implants or before the sequential implant, one year, two years, and three years after. The measures reported are Categories of Auditory Performance II (CAPII), Speech Intelligibility Rating (SIR), Bilateral Listening Skills Profile (BLSP) and Parent Outcome Profile (POP).

RESULTS

Thousand and one children aged from 8 months to almost 18 years were involved, although there were many missing data. In children receiving simultaneous implants after one, two, and three years respectively, median CAP scores were 4, 5, and 6; median SIR were 1, 2, and 3. Three years after receiving simultaneous bilateral cochlear implants, 61% of children were reported to understand conversation without lip-reading and 66% had intelligible speech if the listener concentrated hard. Auditory performance and speech intelligibility were significantly better in female children than males. Parents of children using sequential implants were generally positive about their child's well-being and behaviour since receiving the second device; those who were less positive about well-being changes also generally reported their children less willing to wear the second device.

CONCLUSION

Data from 78% of paediatric cochlear implant centres in the United Kingdom provide a real-world picture of outcomes of children with bilateral implants in the UK. This large reference data set can be used to identify children in the lower quartile for targeted intervention.

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.

Unilateral cochlear implantation in children with a potentially useable contralateral ear

Increasingly, children are considered for a unilateral CI, even if the contralateral ear falls outside current audiological guidelines, especially if they are not considered to be reaching their educational potential. The primary aim was to investigate the benefit of unilateral CI in children currently outside UK [National Institute for Health and Care Excellence Technology Appraisal Guidance. 2009. Cochlear implants for children and adults with severe to profound deafness. NICE technology appraisal guidance [TAG166]. Available January 29, 2016 from http://www.nice.org.uk/ta166 ] audiological guidelines in the contralateral ear. The secondary aim was to measure compliance. A retrospective case review with standard demographic data was performed. Forty-seven children were identified as having received a unilateral CI with the contralateral ear falling outside of current UK audiological criteria. These children were allocated to two groups; with hearing between 50 and 70 dB, and 70 and 90 dB at 2 and 4 kHz in the contralateral ear, respectively. Categories of auditory performance (CAP) were assessed. Pre- and post-operative CAP scores demonstrated a statistically significant improvement in auditory perception. We would suggest that assessing candidacy in individual ears and subsequent unilateral CI, has given these children a benefit they may not otherwise have acquired if they only had bilateral hearing aid.

Simultaneous bilateral cochlear implantation in a five-month-old child with Usher syndrome

OBJECTIVE

To report a rare case of simultaneous bilateral cochlear implantation in a five-month-old child with Usher syndrome.

METHOD

Case report.

RESULTS

A five-month-old boy with Usher syndrome and congenital profound bilateral deafness underwent simultaneous bilateral cochlear implantation. The decision to perform implantation in such a young child was based on his having a supportive family and the desire to foster his audiological development before his vision deteriorated. The subject experienced easily resolvable intra- and post-operative adverse events, and was first fitted with an externally worn audio processor four weeks after implantation. At 14 months of age, his audiological development was age-appropriate.

CONCLUSION

Simultaneous bilateral cochlear implantation is possible, and even advisable, in children as young as five months old when performed by an experienced implantation team.

Cochlear implantation in nontraditional candidates: preliminary results in adolescents with asymmetric hearing loss

OBJECTIVE

Traditionally, children are cochlear implant (CI) candidates if bilateral severe to profound hearing loss is present and amplification benefit is limited. The current study investigated abilities of adolescents with asymmetric hearing loss (one ear with severe to profound hearing loss and better hearing contralaterally), where the poorer ear received a CI and the better ear maintained amplification.

STUDY DESIGN

Within-subject case study.

SETTING

Pediatric hospital, outpatient clinic.

PATIENTS

Participants were 5 adolescents who had not met traditional CI candidacy because of one better hearing ear but did have 1 ear that met criteria and was implanted. All maintained hearing aid (HA) use in the contralateral ear. In the poorer ear, before implant, 3 participants had used amplification, and the other 2 had no HA experience.

MAIN OUTCOME MEASURE

Participants were assessed in 3 listening conditions: HA alone, CI alone, and both devices together (bimodal) for speech recognition in quiet and noise and sound localization.

RESULTS

Three participants had CI open-set speech recognition and significant bimodal improvement for speech recognition and localization compared with the HA or CI alone. Two participants had no CI speech recognition and limited bimodal improvement.

CONCLUSION

Some adolescents with asymmetric hearing loss who are not typical CI candidates can benefit from a CI in the poorer ear, compared with a HA in the better ear alone. Additional study is needed to determine outcomes for this population, especially those who have early onset profound hearing loss in one ear and limited HA experience.

Accessibility to cochlear implants in Belgium: state of the art on selection, reimbursement, habilitation, and outcomes in children and adults

Belgium, and especially the northern region called Flanders, has been a center of expertise in cochlear implants and early hearing screening for many years. Some of their surgeons and engineers were pioneers in the development of cochlear implants and in 1998 Flanders was the first region in Europe to implement a universal hearing screening program for all neonates. The Belgian National Institute for Health and Disability Insurance has reimbursed cochlear implants in children and adults since 1994 and bilateral implantation in children under the age of 12 years since February 2010. These deaf children, screened and implanted early, achieve higher auditory, speech and language outcomes and increasing numbers are going to regular schools using fewer interpreters. In 2010, 93% of severe-to-profound deaf preschool children in Flanders had received cochlear implants and 25% had bilateral implants. Although on average twice as many adults as children are implanted a year in Belgium, we have less research data available from this adult population. Also very little is published about the growth curves and minimal rehabilitation requirements (intensity, duration etc.) after implantation for both children and adults. So, there still remain many challenges for the future.

Factors predicting functional outcomes of cochlear implants in children

This article reports the relationships between a large number of child- and family-related factors and children's functional outcomes, according to parental report, in the domains of spoken language communication, social skills and participation, academic achievement, and independence and identity, through a series of stepwise regression analyses. Parents of 247 children who had received cochlear implants in three eastern states of Australia completed a survey on their expectations and experiences of their children's outcomes with cochlear implants. A number of the independent variables were found to be associated, either positively or negatively, with children's outcomes. Implications for cochlear implant professionals, early intervention programmes, and educational authorities are discussed.

Parents' views on the quality of life of their children 2-3 years after cochlear implantation

OBJECTIVE

Cochlear implants for children are known to have impact on the lives of recipients and their families in a variety of ways. To obtain a clearer picture of these benefits, we explored the quality of life of 36 Finnish children and their families 2-3 years after unilateral cochlear implantation.

METHODS

The studied children were, on average 5 years old, and had received their implant at the median age of 2 years:5 months (range 1:6 to 12:3). Most (67%) of the children used speech, eight (22%) used speech and signs, and four (11%) used sign language as their main communication mode. A third of the children had concomitant problems in addition to their profound hearing impairment. A validated closed-set questionnaire "Children with cochlear implants: parental perspectives" (available, e.g., at http://www.earfoundation.org.uk/research/questionnaires.html) was used to find out parents' views and experiences on implantation and explore life after it.

RESULTS

Parents were most satisfied with improved/expanded social relations, improved communication (the development of spoken language), general functioning with the help of hearing and improved self-reliance of the child. Benefit of cochlear implantation was also detected with the Categories of Auditory Performance (CAP), which was concordant with views of the parents on the progress of their child in the areas of communication and education. When deciding on implantation, the parents particularly expected auditory information to enhance their child's safety in traffic, joining socially the hearing world, and better employment prospects as adults. Concerning the process of implantation, parents especially valued the know-how and fluent services of the implant centre, positive attitude within the family and information received from other families during the time they were considering the implant decision. Parents also found it important that they have the possibility to influence the communication mode that is used in their child's educational setting.

CONCLUSIONS

Parents report that cochlear implants affect their children in a wide variety of ways that cannot be summarized by a single scale. A broader descriptive framework is required to capture their experiences adequately.