What Is the Sensitive Period to Initiate Auditory Stimulation for the Second Ear in Sequential Cochlear Implantation?

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.

Predictive Ability of First-Side Cochlear Implant Performance in Adult Sequential Bilateral Cochlear Implantation

OBJECTIVE

Predictors of second-side cochlear implant performance have not been well studied. We sought to assess whether speech recognition scores from first-side cochlear implant (CI1) could predict second-side cochlear implant (CI2) scores in sequential bilaterally implanted adults.

STUDY DESIGN

Retrospective review using a prospectively collected database.

SETTING

Academic tertiary care hospital.

PATIENTS

Fifty-seven adults with postimplantation speech recognition testing performed at least 12 months after CI2.

INTERVENTION

Sequential bilateral CI.

MAIN OUTCOME MEASURES

CI2 performance at ≥12 months as measured using consonant-nucleus-consonant (CNC) words and AzBio sentences in quiet and +10 dB signal-to-noise ratio (S/N).

RESULTS

CI1 performance scores at ≥12 months were independently associated with CI2 performance scores at ≥12 months for CNC words (β = 0.371 [0.136-0.606], p = 0.003), AzBio sentences in quiet (β = 0.614 [0.429-0.80], p < 0.0001), and AzBio +10 dB S/N (β = 0.712 [0.459-0.964], p < 0.0001). CI1 scores on AzBio in quiet at 0 to 6 months were also independently associated with CI2 AzBio in quiet scores at ≥12 months (β = 0.389 [0.004-0.774], p = 0.048). Hearing loss etiology and duration, age at implantation, interval between CI1 and CI2, duration of hearing aid use, and preimplantation speech recognition testing scores were not consistently associated with CI2 scores at ≥12 months.

CONCLUSIONS

CI1 performance is an independent predictor of second-side performance as measured ≥12 months postimplantation. This may be a clinically useful metric when considering adult sequential bilateral implantation.

Sequential Bilateral Cochlear Implantation With Prolonged Time Intervals

Purpose The aim of the study was to assess whether sequential cochlear implantation (CI) with a prolonged interimplant interval (M = 15.2 years) between the first and second CIs benefited speech recognition and health-related quality of life. Method This prospective study included 14 prelingually deafened participants who received their second CI after a prolonged interimplant interval (M = 15.2 years). Additionally, speech recognition ability over a 12-month period of bilateral implant use was investigated. The results of the speech recognition test in both quiet and noisy conditions were statistically analyzed for each CI alone and both CIs together. Nijmegen Cochlear Implant Questionnaire scores were also collected at activation and at 12 months after activation. Results Improvements in speech recognition ability were observed following the use of the first implant alone and with the use of both implants together; however, progress was much slower with the use of the second implant alone, following its introduction. Furthermore, a significant difference in the trajectory of speech recognition ability was observed between the first and the second implanted ear. According to Nijmegen Cochlear Implant Questionnaire scores, all participants benefitted from bilateral CI after 12 months. Conclusions Prolonged interimplant intervals resulted in asymmetrical speech recognition abilities. A significant improvement in the speech recognition scores was observed with the first implanted ear, and much slower progress was observed with the second implanted ear. However, the "poorer" second implanted ear could provide a considerable beneficial effect on the improved speech recognition and health-related quality of life with the bilateral CI. Supplemental Material https://doi.org/10.23641/asha.12861152.

Long-term Change in the Speech Perception Ability in Pediatric Cochlear Implants and the Effect of the Age at Implantation

OBJECTIVE

We analyzed the long-term changes in speech perception ability of pediatric cochlear implants (CIs) to evaluate the effect of the age at the time of surgery.

STUDY DESIGN

Retrospective.

SETTING

Tertiary care academic center.

PATIENTS

One hundred fourteen prelingually deaf children with CI use duration >10 years.

MAIN OUTCOME MEASURES

Categories of auditory performance (CAP) scores and monosyllabic word recognition scores using the Asan-Samsung Korean word list (ASK-WRS) and a conventional word list (KS-WRS) were the main outcomes. Outcomes were compared according to the age at surgery (group I, 1-2 yr; II, 2.1-3 yr; III, 3.1-7 yr; IV, 7.1-13 yr).

RESULTS

CAP scores reached plateaus at 2.6 to 3.3 years post-CI; groups I to III showed better scores than group IV. The maximum CAP score was obtained in all children of groups I to III and in 65% of group IV. ASK-WRSs reached plateaus at 3.2 to 4.8 years post-CI. Younger patients at CI operation showed better ASK-WRSs (97, 93, 90, and 54% in groups I-IV, respectively), but the differences were not significant (I versus II and II versus III). Ceiling effect (perfect score) was observed in early groups (67, 44, 30, and 0% in groups I-IV). KS-WRSs, which is a challenging test, reached plateaus at 7.2 to 8.4 years postsurgery with no ceiling effect. Early implantees showed significantly better scores (88, 82, 73, and 46% in groups I-IV).

CONCLUSIONS

Speech perception ability after CI showed audiological age-specific improvement evaluated by various test methods. The most challenging test demonstrated long-term performance differences by the age at CI operation.

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.

Bilateral cochlear implantation is regarded as very beneficial: results from a worldwide survey by online questionnaire

PURPOSE

Bilateral cochlear implant (CI) provision is now widely regarded as the most beneficial hearing intervention for acceptable candidates. This study sought to determine if a number of well-regarded hearing professionals at highly reputable clinics shared similar practices and beliefs regarding bilateral CI provision, use, and rehabilitation in children and adults.

METHODS

An 11-question online questionnaire was created and distributed to all 27 clinics in the HEARRING group. Questions 1-5 asked for facts; questions 6-11 asked for opinions.

RESULTS

20 completed questionnaires were returned. All 20 respondents reported that their clinics perform bilateral cochlear implantation in children; 18 do so in adults. Regarding the fact-based questions, bilateral CI provision is more commonly performed and more likely to be reimbursed in children than in adults. Children are also much more likely to be implanted simultaneously than are adults. Regarding the opinion-based questions, respondents gave broadly similar answers. Communication between the CIs and speech coding strategies specifically developed for bilateral CI users were regarded as the two future technologies that would most enhance the benefit of bilateral CI use.

CONCLUSIONS

Most clinics in the HEARRING group are very familiar with bilateral CI provision and hold similar opinions on its results and benefits. Hopefully the results described herein will lead to a greater acceptance and regular reimbursement of bilateral CI provision, especially in adults.

Cochlear Implantation in Postlingually Deaf Adults is Time-sensitive Towards Positive Outcome: Prediction using Advanced Machine Learning Techniques

Given our aging society and the prevalence of age-related hearing loss that often develops during adulthood, hearing loss is a common public health issue affecting almost all older adults. Moderate-to-moderately severe hearing loss can usually be corrected with hearing aids; however, severe-to-profound hearing loss often requires a cochlear implant (CI). However, post-operative CI results vary, and the performance of the previous prediction models is limited, indicating that a new approach is needed. For postlingually deaf adults (n de120) who received CI with full insertion, we predicted CI outcomes using a Random-Forest Regression (RFR) model and investigated the effect of preoperative factors on CI outcomes. Postoperative word recognition scores (WRS) served as the dependent variable to predict. Predictors included duration of deafness (DoD), age at CI operation (ageCI), duration of hearing-aid use (DoHA), preoperative hearing threshold and sentence recognition score. Prediction accuracy was evaluated using mean absolute error (MAE) and Pearson's correlation coefficient r between the true WRS and predicted WRS. The fitting using a linear model resulted in prediction of WRS with r = 0.7 and MAE = 15.6 ± 9. RFR outperformed the linear model (r = 0.96, MAE = 6.1 ± 4.7, p < 0.00001). Cross-hospital data validation showed reliable performance using RFR (r = 0.91, MAE = 9.6 ± 5.2). The contribution of DoD to prediction was the highest (MAE increase when omitted: 14.8), followed by ageCI (8.9) and DoHA (7.5). After CI, patients with DoD < 10 years presented better WRSs and smaller variations (p < 0.01) than those with longer DoD. Better WRS was also explained by younger age at CI and longer-term DoHA. Machine learning demonstrated a robust prediction performance for CI outcomes in postlingually deaf adults across different institutes, providing a reference value for counseling patients considering CI. Health care providers should be aware that the patients with severe-to-profound hearing loss who cannot have benefit from hearing aids need to proceed with CI as soon as possible and should continue using hearing aids until after CI operation.