The Impact of Cochlear Implantation: Cognitive Function, Quality of Life, and Frailty in Older Adults

The Benefits of Cochlear Implantation for Adults: A Systematic Umbrella Review

OBJECTIVES

The uptake of cochlear implants among adults who could benefit (based on pure-tone audiometry) in developed countries is estimated to be less than 10%. Concerns about potential surgical complications, fear of losing residual hearing, and limited awareness about the benefits of this intervention contribute to the low adoption rate. To enhance quality of life and improve the uptake of cochlear implants, it is essential to have a clear understanding of their benefits.

DESIGN

This umbrella review aims to summarize the major benefits of cochlear implant usage in adults, by synthesizing findings from published review articles. A comprehensive search of databases including MEDLINE, EMBASE, PsycINFO, and Google Scholar, was conducted. The search was limited to English-language review articles published between 1990 and 2022, focusing on cochlear implant outcomes in at least 5 adults (aged ≥18 years). Two independent reviewers screened titles, abstracts, and full-text articles, and conducted a quality assessment using the Joanna Briggs Checklist for Systematic Reviews and Research Syntheses.

RESULTS

Forty-two articles were included in this review. There were 15 systematic reviews with meta-analysis, 25 systematic reviews without meta-analysis, and 2 systematic scoping reviews. All 42 articles underwent quality assessment using the Joanna Briggs Institute Checklist for Systematic Reviews and Research Syntheses, of which 40% (n = 17) satisfied 9 out of 11 quality criteria. This umbrella review shows that cochlear implants are associated with improvements in speech perception and recognition as well as improved quality of life and cognition. These benefits are observed in a significant proportion of adults undergoing the procedure, highlighting its effectiveness as a viable intervention for individuals with severe to profound hearing loss.

CONCLUSIONS

The potential benefits of cochlear implantation appear to outweigh the risks and complications associated with the procedure. It is recommended that adults with severe to profound hearing loss in particular, engage in informed discussions with healthcare professionals to consider cochlear implantation as a viable treatment option.

Understanding Patient Utilization Patterns of Cochlear Implant Processors

OBJECTIVE

To evaluate the extent of benefit the second processor provides and to better understand utilization patterns regarding cochlear implant (CI) sound processors.

BACKGROUND

Institutional contracts determine the external CI sound processor hardware that a patient is eligible for. Despite the high prevalence of CI worldwide, there is a paucity in the literature regarding patient preferences and how patients utilize provided external hardware.

METHODS

A close-ended, multiple-choice survey was mailed to all patients over the age of 18 years who underwent CI between 2016 to 2020 at a tertiary academic medical center. Patients who received their CI hardware prior to 2018 were provided 2 processors, whereas those who received their hardware in 2018 or later were provided 1 processor.

RESULTS

A total of 100/263 surveys were returned for a response rate of 38.0%. Of the cohort with 1 processor, 31.3% experienced a period without a functioning processor and access to sound compared to 5.6% of the cohort with 2 processors (P = -.003). Of the cohort with 2 processors, 24.3% noted that they often or always utilize their second processor. When asked how important having a second processor was, 62.9% of the 2-processor group responded that it was very important (P = .001). The most common reason for utilizing the second processor was a damaged primary processor. Patients who received 2 processors had a significantly lower number of postoperative audiology clinic visits for device troubleshooting (P < .001).

CONCLUSION

Patients who have 2 CI external processors identify this as being very important to them and experience significantly less time without access to sound due to lack of a functioning processor. As institutional contracts often dictate whether a patient will receive 1 or 2 sound processors with their CI hardware, it is important to understand patient preferences and utilization patterns in order to guide patient-centric policies.

Cochlear Implantation in Charcot-Marie-Tooth Patients: Speech Perception and Quality of Life

OBJECTIVES

There is a limited understanding of the impact of cochlear implantation (CI) in patients with Charcot-Marie-Tooth disease (CMT), given the scarcity of reported cases. We aim to evaluate the audiological outcomes and quality of life (QoL) after CI in CMT.

METHODS

Multi-institutional, university-affiliated, tertiary-referral centers, retrospective chart review.Our cohort includes 5 patients with CMT. Patients' charts were reviewed for demographic characteristics, operation notes, and pre- and post-implantation audiology evaluation. Patients completed the Cochlear Implant Quality of Life-10 (CIQOL-10) Global questionnaire.

RESULTS

Pre-implantation, the mean pure tone average was 84.1 ± 7.2 dB, and the mean word recognition score was 2.4% in the implanted ear. AzBio sentence test was performed in quiet, revealing a mean of 4 ± 1.4% in the implanted ear. Post-implantation, PTA results were all within the mild hearing loss range (mean 33.0 ± 5.9 dB). Post-CI, AZ-Bio test results were 5%, 65%, and 74% (for 3 patients), and HINT scores were 55% and 58% (for 2 patients). The mean score of the CIQOL-10 questionnaire was 42.7 ± 10.47 (range 1-100). Patients were most satisfied with their ability to listen to the television or radio, have conversations in a quiet environment, and feel comfortable being themselves.

CONCLUSION

To the best of our knowledge, this is the most extensive series of CI in CMT-associated sensorineural hearing loss and auditory neuropathy. Our cohort suggests that CI is a safe and reliable method for hearing rehabilitation that can achieve good speech performance and improve QoL in CMT patients.

Morphometric Analysis and Linear Measurements of the Scala Tympani and Implications in Cochlear Implant Electrodes

HYPOTHESIS

The objective of this study was to perform detailed height and cross-sectional area measurements of the scala tympani in histologic sections of nondiseased human temporal bones and correlate them with cochlear implant electrode dimensions.

BACKGROUND

Previous investigations in scala tympani dimensions have used microcomputed tomography or casting modalities, which cannot be correlated directly with microanatomy visible on histologic specimens.

METHODS

Three-dimensional reconstructions of 10 archival human temporal bone specimens with no history of middle or inner ear disease were generated using hematoxylin and eosin histopathologic slides. At 90-degree intervals, the heights of the scala tympani at lateral wall, midscala, and perimodiolar locations were measured, along with cross-sectional area.

RESULTS

The vertical height of the scala tympani at its lateral wall significantly decreased from 1.28 to 0.88 mm from 0 to 180 degrees, and the perimodiolar height decreased from 1.20 to 0.85 mm. The cross-sectional area decreased from 2.29 (standard deviation, 0.60) mm 2 to 1.38 (standard deviation, 0.13) mm 2 from 0 to 180 degrees ( p = 0.001). After 360 degrees, the scala tympani shape transitioned from an ovoid to triangular shape, corresponding with a significantly decreased lateral height relative to perimodiolar height. Wide variability was observed among the cochlear implant electrode sizes relative to scala tympani measurements.

CONCLUSION

The present study is the first to conduct detailed measurements of heights and cross-sectional area of the scala tympani and the first to statistically characterize the change in its shape after the basal turn. These measurements have important implications in understanding locations of intracochlear trauma during insertion and electrode design.

Evaluation of the Cognitive Function of Adults with Severe Hearing Loss Pre- and Post-Cochlear Implantation Using Verbal Fluency Testing

Hearing loss is a major public health problem with significant evidence correlating it with cognitive performance. Verbal fluency tests are commonly used to assess lexical access. They provide a great deal of information about a subject's cognitive function. The aim of our study was to evaluate phonemic and semantic lexical access abilities in adults with bilateral severe to profound hearing loss and then to re-evaluate a cohort after cochlear implantation. 103 adult subjects underwent phonemic and semantic fluency tests during a cochlear implant candidacy evaluation. Of the total 103 subjects, 43 subjects underwent the same tests at 3 months post-implantation. Our results showed superior performance in phonemic fluency compared to semantic fluency in subjects prior to implantation. Phonemic fluency was positively correlated with semantic fluency. Similarly, individuals with congenital deafness had better semantic lexical access than individuals with acquired deafness. Results at 3 months post-implantation showed an improvement in phonemic fluency. No correlation was found between the evolution of pre- and post-implant fluency and the auditory gain of the cochlear implant, and we found no significant difference between congenital and acquired deafness. Our study shows an improvement in global cognitive function after cochlear implantation without differentiation of the phonemic-semantic pathway.

Do Patients Aged 85 Years and above Benefit from Their Cochlear Implants?

The present study aims to investigate the usage and benefits of cochlear implants (CIs) in elderly patients aged ≥85 years, including their device-handling issues, follow-ups, and the influence on their well-being. The patients answered one questionnaire regarding quality of life, EQ5D-3L, and one questionnaire, obtained from the Swedish CI quality register, regarding usage, handling, satisfaction, remaining difficulties, etc. The medical records were searched for the implantation date, implant model, speech processor model, monosyllabic (MS) word scores, infections over the implant, and compliance regarding scheduled visits to the clinic. The results show that most elderly patients are satisfied full-time users of their implants. Even though most patients had no problems handling their CI, handling issues must be considered. Recurring guidance and training on device operation are needed. We suggest that follow-up visits are essentially needed for this group of patients on a regular basis. CI surgery is considered a safe treatment, even for the elderly. Upgrads to new external equipment (e.g., sound processors) should not be excluded because of their age. The results suggested that the CI positively affected their well-being. This study was approved by the Swedish Ethical Review Authority (5/10-2021, Dnr: 2021-04970).

Effects of auditory rehabilitation with cochlear implant on tinnitus prevalence and distress, health-related quality of life, subjective hearing and psychological comorbidities: Comparative analysis of patients with asymmetric hearing loss (AHL), double-sided (bilateral) deafness (DSD), and single-sided (unilateral) deafness (SSD)

Introduction

Auditory rehabilitation with a cochlear implant (CI), in many cases, positively impacts tinnitus. However, it is unclear if the tinnitus-related benefit of CI is equal for patients with various indications for CI. Therefore, this study aimed to determine differences in tinnitus prevalence and distress, health-related quality of life, subjective hearing, perceived stress, and psychological comorbidities between patients diagnosed with asymmetric hearing loss (AHL), single-sided (unilateral) deafness (SSD), and double-sided (bilateral) deafness (DSD) before and six months after cochlear implantation.

Methods

One hundred-one CI candidates were included in this prospective study (39 AHL patients, 23 DSD patients, and 39 SSD patients). The patients completed questionnaires measuring tinnitus distress, health-related quality of life, subjective hearing, perceived stress, and psychological comorbidities before and 6 months after CI.

Results

The prevalence of tinnitus in the entire cohort (80.2% before CI) decreased 6 months after CI to 71.3%. The DSD group had the lowest tinnitus prevalence at both time points. The degree of tinnitus-induced distress decreased significantly in all three groups after CI. Differences in quality of life, subjective hearing, and psychological comorbidities between the groups at the study onset disappeared after CI. Significant correlations existed between anxiety, depression, and tinnitus distress in AHL and SSD but not in DSD patients before and after CI.

Discussion

Our results demonstrate significant differences between the three groups of CI candidates, which might affect the implantation outcome. These differences suggest a need for personalized psychological counseling during the auditory rehabilitation process, focusing on anxiety and depressive symptoms for SSD and AHL patients.

Cochlear Implantation in Patients With Known Cognitive Impairment: What Are the Benefits?

OBJECTIVE

To evaluate the outcomes of cochlear implantation (CI) in adults with preoperatively diagnosed cognitive impairment.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary-care academic center.

PATIENTS

Adults undergoing CI with preexisting cognitive impairment.

INTERVENTIONS

Cochlear implantation.

MAIN OUTCOME MEASURES

1) Hearing improvement after CI; 2) morbidity and mortality associated with surgery.

RESULTS

Eight patients met inclusion criteria with mean age 77.8 years (SD, 9.6 y) at time of implantation; 7 were included in subsequent analysis as one did not have speech recognition scores. Average preoperative MoCA cognitive score of 22.6 (SD, 3.9, ≤25 demonstrates cognitive impairment). Average follow-up was 29.0 months (SD, 33.3 mo). Two patients passed away at an average 58.0 months (SD, 31.1 mo) after surgery. Median preoperative pure tone average was 86.3 dB HL ( interquartile range 31.3 dB HL) compared with 33.8 dB HL (IQR 5.0 dB HL) postoperatively ( p = <0.001). Median preoperative speech testing score (AzBio/HINT) was 21% (IQR, 24%) compared with 44% (IQR, 21%) postoperatively ( p = <0.001). There were no observed surgical complications during the follow-up period.

CONCLUSIONS

This study demonstrates that patients with cognitive impairment before CI can experience improved hearing, no increased risk of complications, and good longevity after CI. Further prospective studies are needed to further define the utility of CI in patients with impaired cognition.

Association of Baseline Frailty Status and Age With Postoperative Complications After Cochlear Implantation: A National Inpatient Sample Study

OBJECTIVE

To conduct a national registry-based evaluation of the independent associations of chronological age and frailty, as measured by 5- and 11-factor modified frailty index (mFI-5, mFI-11) score, on postoperative outcomes of participants undergoing cochlear implantation (CI).

STUDY DESIGN

Cross-sectional analysis.

SETTING

Multicenter national database.

PARTICIPANTS

Adults 18 years or older who underwent CI during 2001 to 2018.

MAIN OUTCOME MEASURES

Any postoperative complications (determined as the presence of major, minor, or implant-specific), extended hospital length of stay (eLOS) (≥75th percentile of study population), and nonhome discharge destination.

RESULTS

There were 5,130 participants included with a median age of 60 years (interquartile range, 44-73 y) and slight female predominance (53.5%). Under mFI-5 scoring, there were 2,979 (58.1%) robust (mFI-5 = 0), 1710 (33.3%) prefrail (mFI-5 = 1), 362 (7.1%) frail (mFI-5 = 2), and 78 (1.5%) severely frail (mFI-5 ≥ 3) participants. Three hundred twenty-eight (6.49%) participants experienced a postoperative complication, with 320 (6.2%) discharged to a nonhome destination. Multivariate analysis showed no statistically significant correlation between increasing participant age or frailty status and postoperative complications; however, increasing baseline frailty tier showed an independent association with risk of eLOS (severely frail: odds ratio, 4..83; 95% confidence interval, 3.00-7.75; p < 0.001) and nonhome discharge (severely frail: odds ratio, 6.51; 95% confidence interval, 3.81-11.11; p < 0.001). The mFI-11 showed very similar trends.

CONCLUSION

Among those evaluated, this study demonstrates that CI is a low-risk procedure in participants of all ages. Increasing frailty does not predispose to postoperative complications. However, frail patients are at additional risk for an eLOS and nonhome discharge. Short follow-up time, hospital-coding errors, and selection bias of more robust patients may limit the true results of this study.

Geographic Variations in Medicare Cochlear Implantations in the United States

OBJECTIVE

To describe national practice patterns and detail geographic and temporal changes in cochlear implantations (CIs) in the Medicare population.

STUDY DESIGN

Cross-sectional analysis.

SETTING

Medicare B Public Use Files.

PATIENTS

Medicare B fee-for-service patients who underwent CI from 2012 to 2019.

INTERVENTIONS

Cochlear implantations (Current Procedural Terminology code 69930).

MAIN OUTCOME MEASURES

Medicare Part B Public Use Files were used to identify all individual providers who performed CIs from 2012 to 2019. The total number of CIs performed annually was calculated for hospital referral regions (HRRs) as well as U.S. census regions to describe geographic variations and changes over the study period. Average Medicare reimbursement rates were tabulated.

RESULTS

From 2012 of 2019, the number of CIs performed in the Medicare population increased from 1,239 to 2,429, representing a 96.0% increase. In each of the four U.S. census regions, there was a statistically significant increase in the number of CIs performed over the study period. However, of 306 HRR in the United States, cochlear implants were performed in only 117 (38.2%), with the median number of CIs in each HRRs 16.7 (interquartile range, 13-24.2) per year. The median weighted average Medicare reimbursement was $1205.49 (interquartile range, 1161.65-1253.46).

CONCLUSIONS

The number of CIs in the Medicare population has increased from 2012 to 2019. However, widespread geographic variations continue to persist in the United States and represent opportunities toward identifying and acting on the etiologies of persistent disparities in CI.