When is the best timing for the second implant in pediatric bilateral cochlear implantation?

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.

Importance of age at 2nd implantation and interimplant interval to the outcome of bilateral prelingually deafened pediatric cochlear implantation

BACKGROUND

In Taiwan, the number of cases of sequential bilateral pediatric cochlear implantation (CI) is increasing but data regarding its effectiveness and impact of the reimbursement policy are lacking. We examined the speech perception and quality of life (QOL) of bilateral prelingually deaf children who underwent sequential CI, considering the effects of age at the time of second implantation and interimplant interval.

METHODS

We enrolled 124 Mandarin-speaking participants who underwent initial cochlear implant (CI1) in 2001-2019 and a second CI (CI2) in 2015-2020. Patients were followed up for ≥2 years and were categorized into groups based on age at the time of CI2 implantation (<3.5, 3.6-7, 7.1-10, 10.1-13, and 13.1-18 years) and interimplant interval (0.5-3, 3.1-5, 5.1-7, 7.1-10, and >10 years). We evaluated speech perception, device usage rates, and QOL using subjective questionnaires (Speech, Spatial, and Qualities of Hearing and Comprehension Cochlear Implant Questionnaire).

RESULTS

Speech perception scores of CI2 were negatively correlated with ages at the time of CI1 and CI2 implantation and interimplant interval. Older age and a longer interimplant interval were associated with higher nonuse rates for CI2 and worse auditory performance and QOL. Among individuals aged >13 years with interimplant intervals >10 years, up to 44% did not use their second ear. Patients aged 7.1 to 10 years had better speech perception and higher questionnaire scores than those aged 10.1 to 13 and 13.1 to 18 years. Furthermore, patients aged 10.1 to 13 years had a lower rate of continuous CI2 usage compared to those aged 7.1 to 10 years.

CONCLUSION

Timely implantation of CI2 is essential to achieve optimal outcomes, particularly among sequentially implanted patients with long-term deafness in the second ear and no improvement with hearing aids following CI1 implantation. For CI2 implantation, an upper limit of age of 10 years and interimplant interval of 7 years are essential to prevent suboptimal outcomes. These data can provide useful information to implant recipients, their families, and medical and audiological professionals, enabling a comprehensive understanding of the benefits and potential impacts of the timing of CI2 implantation.

Current Issues With Pediatric Cochlear Implantation

Cochlear implants (CIs) have demonstrated a clear functional benefit in children with severe-to-profound sensorineural hearing loss (SNHL) and thus have gained wide acceptance for treating deafness in the pediatric population. When evaluating young children for cochlear implantation, there are unique considerations beyond the standard issues addressed during surgery in adults. Because of advances in genetic testing, imaging resolution, CI technology, post-implant rehabilitation, and other factors, issues related to CI surgery in children continue to evolve. Such factors have led to changes in candidacy guidelines, vaccine requirements, and lowering of age requirement for surgery. In addition, differences in the anatomy and physiology of infants require special attention to ensure safety when operating on young children. This review summarizes these issues and provides guidance for surgeons treating children with SNHL.

The impact of unilateral, simultaneous, or sequential cochlear implantation on pediatric language outcomes

OBJECTIVES

The purpose of this study was to determine the impact of unilateral versus bilateral cochlear implantation on receptive and expressive spoken language outcomes. Secondary aims were to investigate factors timing of first and second implant placement and reliance on government funded health plans on language outcome.

METHODS

This was a retrospective chart review of spoken language users with bilateral severe-to-profound hearing loss. A total of 204 children were included, 105 in the bilateral group and 99 in the unilateral group. Multiple regression analyses were completed to investigate factors that influence language outcomes at age 5.

RESULTS

Recipients who received bilateral CIs performed significantly higher on measures of receptive and expressive language than those with unilateral implants.

DISCUSSION

This study demonstrates that bilateral implantation has a significant impact on receptive and expressive aspects of language development, and should be strongly considered as standard practice for children with bilateral severe to profound hearing loss.

CONCLUSION

These results indicate that families should be counseled that language outcomes are better with bilateral cochlear implantation than unilateral implantation. Cochlear implant teams should continue to consider the impact of socioeconomic status on outcomes and explore new methods to reduce the impacts and barriers of poverty to language development.

The Effect of Cochlear Implant Interval on Spoken Language Skills of Pediatric Bilateral Cochlear Implant Users

OBJECTIVE

To examine the effects of cochlear implant (CI) interval (time between CI surgeries) on receptive vocabulary and receptive language skills for children with bilateral CIs.

STUDY DESIGN

A prospective cross-sectional study design.

SETTING

Participants were recruited from, and tested at, oral schools for the deaf and pediatric audiology clinics across the United States.

PATIENTS

Eighty-eight children, 4 to 9 years of age, with bilateral CIs and known hearing histories. Twenty-three participants received CIs simultaneously and 65 received CIs sequentially. Of those implanted sequentially, 86% wore a hearing aid (HA) on the non-implanted ear during the CI interval.

INTERVENTION

Bilateral cochlear implantation.

MAIN OUTCOME MEASURES

Receptive vocabulary was measured via the Peabody Picture Vocabulary Test (PPVT). Receptive language skills were measured via the Clinical Evaluation of Language Fundamentals (CELF).

RESULTS

Multiple linear regression models indicate better receptive vocabulary and receptive language skills are associated with earlier ages at first CI (CI 1), but not with shorter CI intervals.

CONCLUSIONS

Early cochlear implantation (i.e., age at CI 1) is critical for better receptive vocabulary and receptive language skills. Shorter CI intervals are not associated with better receptive vocabulary and receptive language skills for these 88 children, who nearly all used bimodal hearing during the interval. Use of a HA at the non-implanted ear, before receipt of a second CI (CI 2), may mitigate the effects of early bilateral auditory deprivation.

Functional near-infrared spectroscopy as a tool for assessing speech and spoken language processing in pediatric and adult cochlear implant users

Much of what is known about the course of auditory learning in following cochlear implantation is based on behavioral indicators that users are able to perceive sound. Both prelingually deafened children and postlingually deafened adults who receive cochlear implants display highly variable speech and language processing outcomes, although the basis for this is poorly understood. To date, measuring neural activity within the auditory cortex of implant recipients of all ages has been challenging, primarily because the use of traditional neuroimaging techniques is limited by the implant itself. Functional near-infrared spectroscopy (fNIRS) is an imaging technology that works with implant users of all ages because it is non-invasive, compatible with implant devices, and not subject to electrical artifacts. Thus, fNIRS can provide insight into processing factors that contribute to variations in spoken language outcomes in implant users, both children and adults. There are important considerations to be made when using fNIRS, particularly with children, to maximize the signal-to-noise ratio and to best identify and interpret cortical responses. This review considers these issues, recent data, and future directions for using fNIRS as a tool to understand spoken language processing in children and adults who hear through a cochlear implant.

Sequential pediatric bilateral cochlear implantation: The effect of time interval between implants

OBJECTIVE

To examine speech intelligibility in children subjected to sequential bilateral cochlear implants (CI) surgery and to assess the influence of the inter-stage interval duration.

INTRODUCTION

Binaural hearing recovery can have additional benefits, especially in speech and language development in patients with congenital profound sensorineural hearing loss; so recently there has been an increase in the number of children receiving bilateral CI.

METHODS

Twenty-seven children who underwent sequential bilateral cochlear implant (SBCI) with a short (1-3 yrs), medium (4-6 yrs) and long (7-12 yrs) range interval between both implantations, respectively, were evaluated. All patients underwent periodic speech perception test in quiet and noise after second implant activation in three conditions: with the first or second implant alone and with both implants. Results were examined according to the inter-stage interval.

RESULTS

Speech intelligibility in noise was significantly better under bilateral conditions than either ear alone, in all three groups. Small improvements were seen in quiet, especially in the third group (6-12 yrs).

CONCLUSION

Benefits of second implant in the early-implanted children and after a short inter-implant delay are more evident. However our study support that, even after a long period of deafness and despite a prolonged inter-stage interval, sequential bilateral cochlear implantation should be considered.

LEVEL OF EVIDENCE

Level 4.

Functional near-infrared spectroscopy for neuroimaging in cochlear implant recipients

Functional neuroimaging can provide insight into the neurobiological factors that contribute to the variations in individual hearing outcomes following cochlear implantation. To date, measuring neural activity within the auditory cortex of cochlear implant (CI) recipients has been challenging, primarily because the use of traditional neuroimaging techniques is limited in people with CIs. Functional near-infrared spectroscopy (fNIRS) is an emerging technology that offers benefits in this population because it is non-invasive, compatible with CI devices, and not subject to electrical artifacts. However, there are important considerations to be made when using fNIRS to maximize the signal to noise ratio and to best identify meaningful cortical responses. This review considers these issues, the current data, and future directions for using fNIRS as a clinical application in individuals with CIs. This article is part of a Special Issue entitled <Annual Reviews 2016>.

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.

Clinical and logopaedic results of simultaneous and sequential bilateral implants in children with severe and/or profound bilateral sensorineural hearing loss: A literature review

This article carries out a literature review of the advantages and limitations of the simultaneous bilateral cochlear implantation (SCI) compared to those of the sequential bilateral cochlear implantation (SBCI) and the unilateral cochlear implantation (UCI). The variables analysed in said comparison are: safety and surgical technique, SCI incidence, effectiveness, impact of the inter-implant interval, costs and financing, impact on brain plasticity, impact on speech and language development, main benefits, main disadvantages and concerns, and predictive factors of prognosis. Although the results are not conclusive, all variables analysed seem to point towards observable benefits of SCI in comparison with SBCI or UCI. This tendency should be studied in more depth in multicentre studies with higher methodological rigour, more comprehensive samples and periods and other determining variables (age at the time of implantation, duration and degree of the hearing loss, rehabilitation methodologies used, family involvement, etc.).