A Guinea Pig Model Suggests That Objective Assessment of Acoustic Hearing Preservation in Human Ears With Cochlear Implants Is Confounded by Shifts in the Spatial Origin of Acoustically Evoked Potential Measurements Along the Cochlear Length.

OBJECTIVES: Our recent empirical findings have shown that the auditory nerve compound action potential (CAP) evoked by a low-level tone burst originates from a narrow cochlear region tuned to the tone burst frequency. At moderate to high sound levels, the origins shift to the most sensitive audiometric regions rather than the extended high-frequency regions of the cochlear base. This means that measurements evoked from extended high-frequency sound stimuli can shift toward the apex with increasing level. Here we translate this study to understand the spatial origin of acoustically evoked responses from ears that receive cochlear implants, an emerging area of research and clinical practice that is not completely understood. An essential step is to first understand the influence of the cochlear implant in otherwise naive ears. Our objective was to understand how function of the high-frequency cochlear base, which can be excited by the intense low-frequency sounds that are frequently used for objective intra- and postoperative monitoring, can be influenced by the presence of the cochlear implant. DESIGN: We acoustically evoked responses and made measurements with an electrode placed near the guinea pig round window. The cochlear implant was not utilized for either electrical stimulation or recording purposes. With the cochlear implant in situ, CAPs were acoustically evoked from 2 to 16 kHz tone bursts of various levels while utilizing the slow perfusion of a kainic acid solution from the cochlear apex to the cochlear aqueduct in the base, which sequentially reduced neural responses from finely spaced cochlear frequency regions. This cochlear perfusion technique reveals the spatial origin of evoked potential measurements and provides insight on what influence the presence of an implant has on acoustical hearing. RESULTS: Threshold measurements at 3 to 11 kHz were elevated by implantation. In an individual ear, thresholds were elevated and lowered as cochlear implant was respectively inserted and removed, indicative of "conductive hearing loss" induced by the implant. The maximum threshold elevation occurred at most sensitive region of the naive guinea pig ear (33.66 dB at 8 kHz), making 11 kHz the most sensitive region to acoustic sounds for guinea pig ears with cochlear implants. Conversely, the acute implantation did not affect the low-frequency, 500 Hz thresholds and suprathreshold function, as shown by the auditory nerve overlapped waveform. As the sound pressure level of the tone bursts increased, mean data show that the spatial origin of CAPs along the cochlear length shifted toward the most sensitive cochlear region of implanted ears, not the extended high-frequency cochlear regions. However, data from individual ears showed that after implantation, measurements from moderate to high sound pressure levels originate in places that are unique to each ear. CONCLUSIONS: Alterations to function of the cochlear base from the in situ cochlear implant may influence objective measurements of implanted ears that are frequently made with intense low-frequency sound stimuli. Our results from guinea pigs advance the interpretation of measurements used to understand how and when residual acoustic hearing is lost in human ears receiving a cochlear implant.

A country-wide health policy in Chile for deaf adults using cochlear implants: Analysis of health determinants and social impacts.

BACKGROUND: Post-lingual deafness represents a critical challenge for adults' well-being with substantial public health burdens. One treatment of choice has been cochlear implants (CI) for people with severe to profound hearing loss (HL). Since 2018, Chile has implemented a high-cost policy to cover CI treatment, the "Ley Ricarte Soto" (LRS) health policy. However, wide variability exists in the use of this device. To date, no related study has been published on policy evaluation in Chile or other Latin American countries. OBJECTIVES: This study aimed to evaluate the impact of the LRS policy on the treatment success and labour market inclusion among deaf or hard of hearing (DHH) adults using CI. We examined and characterised outcomes based on self-reports about treatment success and occupation status between 2018 and 2020. DESIGN: We performed a prospective study using hospital clinical records and an online questionnaire with 76 DHH adults aged >15 who had received CIs since the introduction of the LRS policy in 2018. Using univariate and multivariate regression models, we investigated the relationship between demographic, audiological, and social determinants of health and outcomes, including treatment success for social inclusion (International Outcome inventory for Hearing Aids and CIs assessment: IOI-HA) and occupation status for labour market inclusion. RESULTS: Our study showed elevated levels of treatment success in most of the seven sub-scores of the IOI-HA assessment. Similarly, around 70% of participants maintained or improved their occupations after receiving their CI. We found a significant positive association between treatment success and market inclusion. Participants diagnosed at younger ages had better results than older participants in both outcomes. Regarding social determinants of health, findings suggested participants with high social health insurance and a shorter commute time to the clinic had better results in treatment success. For labour market inclusion, participants with high education levels and better pre- CI occupation had better post-CI occupation status. CONCLUSIONS: In evaluating the LRS policy for providing CIs for DHH adults in Chile, we found positive effects relating to treatment success and occupation status. Our study supports the importance of age at diagnosis and social determinants of health, which should be assessed by integrating public services and bringing them geographically closer to each beneficiary. Although evidence-based guidelines for candidate selection given by the LRS policy might contribute to good results, these guidelines could limit the policy access to people who do not meet the requirements of the guidelines due to social inequalities.

Automatic electrode scalar location assessment after cochlear implantation using a novel imaging software.

As of today, image-based assessment of cochlear implant electrode array location is not part of the clinical routine. Low resolution and contrast of computer tomography (CT) imaging, as well as electrode array artefacts, prevent visibility of intracochlear structures and result in low accuracy in determining location of the electrode array. Further, trauma assessment based on clinical-CT images requires a uniform image-based trauma scaling. Goal of this study was to evaluate the accuracy of a novel imaging software to detect electrode scalar location. Six cadaveric temporal bones were implanted with Advanced Bionics SlimJ and Mid-Scala electrode arrays. Clinical-CT scans were taken pre- and postoperatively. In addition, micro-CTs were taken post-operatively for validation. The electrode scalar location rating done by the software was compared to the rating of two experienced otosurgeons and the micro-CT images. A 3-step electrode scalar location grading scale (0 = electrode in scala tympani, 1 = interaction of electrode with basilar membrane/osseous spiral lamina, 2 = translocation of electrode into scala vestibuli) was introduced for the assessment. The software showed a high sensitivity of 100% and a specificity of 98.7% for rating the electrode location. The correlation between rating methods was strong (kappa > 0.890). The software gives a fast and reliable method of evaluating electrode scalar location for cone beam CT scans. The introduced electrode location grading scale was adapted for assessing clinical CT images.

Assessment of Binaural Benefits in Hearing and Hearing-Impaired Listeners.

PURPOSE: The purpose of this study was to (a) investigate which speech material is most appropriate as stimulus in head shadow effect (HSE) and binaural squelch (SQ) tests, (b) obtain normative values of both tests using the material decided to be optimal, and (c) explore the results in bilateral cochlear implant (CI) users. METHOD: Study participants consisted of 30 normal-hearing (NH) persons and 34 bilateral CI users. This study consisted of three phases. In the first phase, three different speech materials (1) monosyllabic words, (2) spondee words, and (3) sentences were compared in terms of (a) effect size, (b) test-retest reliability, and (c) interindividual variability. In the second phase, the speech material selected in the first phase was used to test a further 24 NHs to obtain normative values for both tests. In the third phase, tests were administered to a further 23 bilateral CI users, together with localization test and the Speech, Spatial, and Qualities of Hearing scale. RESULTS: The results of the first phase indicated that spondees and sentences were more robust materials compared with monosyllables. Although the effect size and interindividual variability were comparable for spondees and sentences, sentences had higher test-retest reliability in this sample of CI users. With sentences, the mean (± standard deviation) HSE and SQ in the NH group were 58 ± 14% and 22 ± 11%, respectively. In the CI group, the mean HSE and SQ were 49 ± 13% and 13 ± 14%, respectively. There were no statistically significant correlations between the test results and the interval between the implantations, the length of binaural listening experience, or the asymmetry between the ears. CONCLUSIONS: Sentences are preferred as stimulus material in the binaural HSE and SQ tests. Normative data are given for HSE and SQ with the LiCoS (linguistically controlled sentences) test. HSE is present for all bilateral CI users, whereas SQ is present in approximately seven out of 10 cases.

Complication profile in a cochlear implantation- surgical audit in a large study population of low socio-economic status in a developing country.

OBJECTIVES: To audit surgical complications and their management in cochlear implant (CI) recipients in a tertiary care referral otorhinolaryngology center in South India. MATERIALS AND METHODS: Hospital data on 1,250 CI surgeries performed from June 2013 to December 2020 was reviewed. This is an analytical study with data collected from medical records. The demographic details, complications, management protocols and relevant literature were reviewed. Patients were divided into the following five age groups: 0-3 years, 3-6 years, 6-13 years, 13-18 years and above 18 years. Complications were divided into major and minor and complication occurrence was divided into peri-operative, early post-operative, and late post-operative, and the results were analyzed. RESULTS: The overall major complication rate was 9.04% (including 6.0% due to device failure). If the device failure rate was excluded, the major complication rate was 3.04%. The minor complication rate was 6%. DISCUSSION: CI is the gold standard in the management of patients with severe to profound hearing loss with minimal benefit from conventional hearing aids. Experienced tertiary care CI referral and teaching centers manage complicated implantation cases. Such centers typically audit their surgical complications, providing important reference data for young implant surgeons and newer centers. CONCLUSION: Although not bereft of complications, the list of complications and its prevalence is sufficiently low to warrant the advocacy of CI worldwide, including developing countries with low socio-economic status.

Cochlear implantation in advanced otosclerosis: utility of pre-operative radiological assessment in predicting intra-operative difficulty and final electrode position.

OBJECTIVE: This study aimed to determine if pre-operative radiological scoring can reliably predict intra-operative difficulty and final cochlear electrode position in patients with advanced otosclerosis. METHOD: A retrospective cohort study of advanced otosclerosis patients who underwent cochlear implantation (n = 48, 52 ears) was compared with a larger cohort of post-lingually deaf adult patients (n = 1414) with bilateral hearing loss and normal cochlear anatomy. Pre-operative imaging for advanced otosclerosis patients and final electrode position were scored and correlated with intra-operative difficulty and speech outcomes. RESULTS: Advanced otosclerosis patients benefit significantly from cochlear implantation. Mean duration of deafness was longer in the advanced otosclerosis group (19.5 vs 14.3 years; p < 0.05). CONCLUSION: Anatomical changes in advanced otosclerosis can result in increased difficulty of surgery. Evidence of pre-operative cochlear luminal changes was associated with intra-operative difficult insertion and final non-scala tympani position. Nearly all electrodes implanted in the advanced otosclerosis cohort were peri-modiolar. No reports of facial nerve stimulation were observed.

Evaluation of cost data associated with pediatric cochlear implantation (CI) throughout 2016-2021.

INTRODUCTION: Cochlear Implants (CI) are a mainstay in the treatment of severe sensorineural hearing loss with proven cost-effectiveness and improved quality of life. However, costs associated with CI are variable. During the Covid-19 pandemic, elective surgeries decreased. The investigation into how the pandemic affected CI procedures, costs, and demographic utilization has not been elucidated. METHODS: A retrospective cohort study using the Pediatric Health Information System® (PHIS) database, which consists of 50 children's hospitals, was performed. Regions were defined according to PHIS guidelines. We evaluated number of CIs, total charges and costs, Charge to Cost Ratios (CCR), demographic information, and subgrouped this analysis by region throughout 2016-2021. Charges were adjusted by CMS wage index for hospital location. RESULTS: During the years of 2016-2021, there was a rising number of CIs every year except for 2020 which had a decrease, largely driven by the southern and midwestern regions. The median number of cases did not differ between the years. The median adjusted charges increased every year, but not significantly ($103,883-$125,394). The median CCR also did not differ throughout the years (2.7-3.1). Still, there was a larger interquartile range in 2021 (2.3-4.4) for the median CCR compared to all other years (2.1-3.8), particularly in the South. The percentage of white, non-Hispanic/Latino patients who underwent CI was larger in 2020-2021 (78-79.8 %) compared to 2016-2019 (73.3-77.5 %). CONCLUSIONS: The number of CIs in 2020 was lower than in 2019 or 2021. The median CCR for CI procedures increased from 2016 to 2021 but not significantly. The range of CCR was larger in 2021 compared to the years prior, suggestive of cost shifting by some hospitals to offset the loss in revenue. There was a small but significant increase in white, non-Hispanic patients receiving CI in 2020 and 2021, suggestive of a socio-economic shift in care post pandemic.

Cognitive Assessment in Elderly Cochlear Implant Recipients: Long-Term Analysis.

OBJECTIVES: To examine long-term speech and cognition outcomes in older adult cochlear implant (CI) recipients. First, by evaluating if CI performance was maintained over an extended follow-up period regardless of preoperative cognitive status. Secondly, by evaluating if there was a difference in the rate of cognitive decline between preoperative mild and normal cognition following CI over an extended period of time. STUDY DESIGN AND SETTING: Retrospective cohort study. METHODS: CI recipients ≥65 years of age implanted between 2009 and 2014 with 4+ years follow up. Pre- and postoperative audiometric and speech outcome assessments were collected. Cognitive status was measured using the mini mental status examination (MMSE) at numerous time points. RESULTS: Fifty-three patients met inclusion. Patients were divided into two groups based on preoperative MMSE with scores considered normal (28-30) and those with mildly impaired cognition (MIC, scores 25-27). Audiometric and speech performance improved significantly at one-year post implantation and this was maintained without significant change at 4+ years, regardless of cognitive status. Mixed modeling analysis controlling for age demonstrated no significant difference in the rate of cognitive decline at 4+ years post implantation between the normal cognition cohort (1.74; 95%CI 0.89-2.6) and MIC (2.9; 95%1.91-3.88). CONCLUSION: Speech performance was significantly improved and sustained after CI in both normal cognition and MIC patients. The rate of cognitive decline in older adult CI patients appears to be similar regardless of preoperative cognitive status. Although results demonstrate rates of cognitive decline following CI did not differ between cognition groups over 4+ years, future studies will need to further investigate this over extended time periods with a more comprehensive cognitive testing battery. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2379-2387, 2023.

Health State Utility Values Associated with Cochlear Implants in Adults: A Systematic Review and Network Meta-Analysis.

OBJECTIVES: The cost-effectiveness of bilateral cochlear implants in adults remains uncertain despite established clinical benefits. In cost-effectiveness studies, benefit is often measured by change in health state utility value (HSUV), a single number summary of health-related quality of life anchored at 0 (state of being dead) and 1 (perfect health). Small differences in bilateral cochlear implant HSUV change conclusions of published models, and invalid estimates can therefore mislead policy and funding decisions. As such, we aimed to review and synthesize published HSUV estimates associated with cochlear implants. DESIGN: We included observational or experimental studies reporting HSUV for adult patients (age ≥18 years) with at least moderate-profound sensorineural hearing loss in both ears who received unilateral or bilateral cochlear implants. We searched MEDLINE, EMBASE, PsycINFO, and Cochrane Library databases up to May 1, 2021. Study and participant characteristics and HSUV outcomes were extracted. Narrative synthesis is reported for all studies. A Bayesian network meta-analysis was conducted to generate pooled estimates for the mean difference in HSUV for three comparisons: (1) unilateral cochlear implant versus preimplant, (2) bilateral cochlear implants versus preimplant, (3) bilateral versus unilateral cochlear implants. Our principal measure was pooled mean difference in HSUV. RESULTS: Thirty-six studies reporting unique patient cohorts were identified. Health Utilities Index, 3 (HUI-3) was the most common HSUV elicitation method. HSUV from 19 preimplant mean estimates (1402 patients), 19 unilateral cochlear implant mean estimates (1701 patients), and 5 bilateral cochlear implants mean estimates (83 patients) were pooled to estimate mean differences in HUI-3 HSUV by network meta-analysis. Compared with preimplant, a unilateral cochlear implant was associated with a mean change in HSUV of +0.17 (95% credible interval [CrI] +0.12 to +0.23) and bilateral cochlear implants were associated with a mean change of +0.25 (95% CrI +0.12 to +0.37). No significant difference in HSUV was detected for bilateral compared with unilateral cochlear implants (+0.08 [95% CrI -0.06 to +0.21]). Overall study quality was moderate. CONCLUSIONS: The findings of this review and network meta-analysis comprise the best-available resource for parameterization of cost-utility models of cochlear implantation in adults and highlight the need to critically evaluate the validity of available HSUV instruments for bilateral cochlear implant populations.Protocol registration: PROSPERO (CRD42018091838).

Monitoring Cochlear Health With Intracochlear Electrocochleography During Cochlear Implantation: Findings From an International Clinical Investigation.

OBJECTIVES: Electrocochleography (ECochG) is emerging as a tool for monitoring cochlear function during cochlear implant (CI) surgery. ECochG may be recorded directly from electrodes on the implant array intraoperatively. For low-frequency stimulation, its amplitude tends to rise or may plateau as the electrode is inserted. The aim of this study was to explore whether compromise of the ECochG signal, defined as a fall in its amplitude of 30% or more during insertion, whether transient or permanent, is associated with poorer postoperative acoustic hearing, and to examine how preoperative hearing levels may influence the ability to record ECochG. The specific hypotheses tested were threefold: (a) deterioration in the pure-tone average of low-frequency hearing at the first postoperative follow-up interval (follow-up visit 1 [FUV1], 4 to 6 weeks) will be associated with compromise of the cochlear microphonic (CM) amplitude during electrode insertion (primary hypothesis); (b) an association is observed at the second postoperative follow-up interval (FUV2, 3 months) (secondary hypothesis 1); and (c) the CM response will be recorded earlier during electrode array insertion when the preoperative high-frequency hearing is better (secondary hypothesis 2). DESIGN: International, multi-site prospective, observational, between groups design, targeting 41 adult participants in each of two groups, (compromised CM versus preserved CM). Adult CI candidates who were scheduled to receive a Cochlear Nucleus CI with a Slim Straight or a Slim Modiolar electrode array and had a preoperative audiometric low-frequency average thresholds of ≤80 dB HL at 500, 750, and 1000 Hz in the ear to be implanted, were recruited from eight international implant sites. Pure tone audiometry was measured preoperatively and at postoperative visits (FUV1 and follow-up visit 2 [FUV2]). ECochG was measured during and immediately after the implantation of the array. RESULTS: From a total of 78 enrolled individuals (80 ears), 77 participants (79 ears) underwent surgery. Due to protocol deviations, 18 ears (23%) were excluded. Of the 61 ears with ECochG responses, amplitudes were < 1 µV throughout implantation for 18 ears (23%) and deemed "unclear" for classification. EcochG responses >1 µV in 43 ears (55%) were stable throughout implantation for 8 ears and compromised in 35 ears. For the primary endpoint at FUV1, 7/41 ears (17%) with preserved CM had a median hearing loss of 12.6 dB versus 34/41 ears (83%) with compromised CM and a median hearing loss of 26.9 dB ( p < 0.014). In assessing the practicalities of measuring intraoperative ECochG, the presence of a measurable CM (>1 µV) during implantation was dependent on preoperative, low-frequency thresholds, particularly at the stimulus frequency (0.5 kHz). High-frequency, preoperative thresholds were also associated with a measurable CM > 1 µV during surgery. CONCLUSIONS: Our data shows that CM drops occurring during electrode insertion were correlated with significantly poorer hearing preservation postoperatively compared to CMs that remained stable throughout the electrode insertion. The practicality of measuring ECochG in a large cohort is discussed, regarding the suggested optimal preoperative low-frequency hearing levels ( < 80 dB HL) considered necessary to obtain a CM signal >1 µV.

Speech comprehension in noise-considerations for ecologically valid assessment of communication skills ability with cochlear implants.

BACKGROUND: Nowadays, cochlear implant (CI) patients mostly show good to very good speech comprehension in quiet, but there are known problems with communication in everyday noisy situations. There is thus a need for ecologically valid measurements of speech comprehension in real-life listening situations for hearing-impaired patients. The additional methodological effort must be balanced with clinical human and spatial resources. This study investigates possible simplifications of a complex measurement setup. METHODS: The study included 20 adults from long-term follow-up after CI fitting with postlingual onset of hearing impairment. The complexity of the investigated listening situations was influenced by changing the spatiality of the noise sources and the temporal characteristics of the noise. To compare different measurement setups, speech reception thresholds (SRT) were measured unilaterally with different CI processors and settings. Ten normal-hearing subjects served as reference. RESULTS: In a complex listening situation with four loudspeakers, differences in SRT from CI subjects to the control group of up to 8 dB were found. For CI subjects, this SRT correlated with the situation with frontal speech signal and fluctuating interference signal from the side with R2 = 0.69. For conditions with stationary interfering signals, R2 values <0.2 were found. CONCLUSION: There is no universal solution for all audiometric questions with respect to the spatiality and temporal characteristics of noise sources. In the investigated context, simplification of the complex spatial audiometric setting while using fluctuating competing signals was possible.

Evolution of the candidacy requirements and patient perioperative assessment protocols for cochlear implantation.

Cochlear implantation as an approved clinical therapy ushered in an exciting era of innovation for the treatment of hearing loss. The U.S. Food and Drug Administration approved the use of cochlear implants as a treatment option for adults with profound sensorineural hearing loss in 1985. The landscape for treating adults and children with significant hearing loss has changed dramatically over the last three decades. The purpose of this paper is to examine the evolving regulatory process and changes to clinical care. A significant emerging trend in cochlear implantation is the consideration of steroids to preserve hearing during and following surgery. This parallels the quest for hearing preservation in noise-induced hearing disorders, especially considering the current interest in biological drug therapies in this population. The future will likely usher in an era of combination therapeutics utilizing drugs and cochlear implantation. For over 30+ years and following regulatory compliance, the Rocky Mountain Ear Center has developed an extensive candidacy and outcome assessment protocol. This systematic approach evaluates both unaided and aided auditory performance during candidacy stages and post-implantation. Adjunctive measures of cognition and quality-of-life augment the auditory assessment in specific populations. Practical insights into lessons learned have directed further clinical research and have resulted in beneficial changes to clinical care.

[Speech comprehension in noise-considerations for ecologically valid assessment of communication skills ability with cochlear implants. German version]. / Sprachverstehen im Störschall ­ Überlegungen zur ökologisch validen Bewertung der Kommunikationsfähigkeit mit Cochleaimplantat.

BACKGROUND: Nowadays, cochlear implant (CI) patients mostly show good to very good speech comprehension in quiet, but there are known problems with communication in everyday noisy situations. There is thus a need for ecologically valid measurements of speech comprehension in real-life listening situations for hearing-impaired patients. The additional methodological effort must be balanced with clinical human and spatial resources. This study investigates possible simplifications of a complex measurement setup. METHODS: The study included 20 adults from long-term follow-up after CI fitting with postlingual onset of hearing impairment. The complexity of the investigated listening situations was influenced by changing the spatiality of the noise sources and the temporal characteristics of the noise. To compare different measurement setups, speech reception thresholds (SRT) were measured unilaterally with different CI processors and settings. Ten normal-hearing subjects served as reference. RESULTS: In a complex listening situation with four loudspeakers, differences in SRT from CI subjects to the control group of up to 8 dB were found. For CI subjects, this SRT correlated with the situation with frontal speech signal and fluctuating interference signal from the side with R2 = 0.69. For conditions with stationary interfering signals, R2 values <0.2 were found. CONCLUSION: There is no universal solution for all audiometric questions with respect to the spatiality and temporal characteristics of noise sources. In the investigated context, simplification of the complex spatial audiometric setting while using fluctuating competing signals was possible.

ARCHS: adult recipients of cochlear implants: health and social long-term outcomes-a state-specific and national population-based retrospective cohort study protocol.

INTRODUCTION: While the majority of adults with severe-to-profound hearing loss and poor speech perception outcomes with hearing aids benefit from receiving a cochlear implant, the long-term health and social benefits for implant recipients are yet to be explored. The objective of the ARCHS research is to provide a better understanding of the health and social factors that play a role in the lives of adults with a cochlear implant up to 10 years after the procedure. METHOD AND ANALYSIS: This research will involve conducting two retrospective cohort studies of adults aged ≥18 years who received a cochlear implant during 2011-2021 using linked administrative data first within New South Wales (NSW) and second Australia-wide. It will examine health service use and compare health and social outcomes for younger (18-64 years) and older (≥65 years) cochlear implant recipients. ETHICS AND DISSEMINATION: Ethical approval was received from the NSW Population Health Services Research Ethics Committee for the NSW cohort study (Reference: 2022/ETH00382/2022.07) and from the Macquarie University ethics committee for the national cohort study (Reference: 520221151437084). Research findings will be published in peer-reviewed journals and presented at scientific conferences.

Assessment of outcome measures after audiological computer-based auditory training in cochlear implant children.

OBJECTIVE: To validate the clinical use of acoustic change complex (ACC) as an objective outcome measure of auditory training in Egyptian cochlear implant (CI) children and explore how far electrophysiological measures could be correlated to behavioral measures in assessing training outcome. Also to explore the efficacy of computer-based auditory training programs (CBATP) in the rehabilitation process of CI children. METHODS: Sixty Arabic speaking children participated in the present study. Forty children using monaural CI device served as study group (20 children in subgroup A and 20 children in subgroup B). Both subgroups received traditional speech therapy sessions, additionally subgroup (A) children received computer-based auditory training program (CBATP) at home for three months. Their age ranged from 8 to 17 years. 20 age and sex-matched normal hearing children served as control group as a standardization for the stimuli used to elicit ACC. The study group children were subjected to detailed history taking, parent reported questionnaire (MAIS, Arabic version), aided sound field evaluation, psychophysical evaluation using auditory fusion test (AFT), speech perception testing according to language age, ACC in response to gaps in 1000 Hz tones and language evaluation. This work-up was repeated after 3&6 months for both study subgroups. RESULTS: Children of study subgroup (A) showed improvement of auditory fusion test (AFT) thresholds at 3 & 6 months post-training follow up. As regards acoustic change complex (ACC), it can be detected in 85% of subgroup (A) children, 85% of subgroup (B) children and 100% of control group children. Lower ACC gap detection thresholds were obtained only after 3 months in subgroup (A), while after 6 months in subgroup (B). There were statistically significant differences between initial assessment and 3 & 6 months follow up as regards ACC P1 and N2 latencies and amplitudes in both study subgroups, however in subgroup (A), ACC P1 amplitude at 6 months post-training was significantly larger than values of 3 months follow up. There was highly significant correlation between thresholds of AFT and ACC gap detection threshold. CONCLUSIONS: ACC can be used as a reliable tool for evaluating auditory training outcome in CI children. ACC gap detection threshold can predict psychophysical temporal resolution after auditory training in difficult to test population. CBATP is an easy and accessible method which may be effective in improving CI outcome.

The Impact of the Location of Chorda Tymapni Nerve Origin on the Round Window Accessibility During Pediatric Cochlear Implantation: A Radioclinical Assessment.

OBJECTIVES: This study assessed the impact of the location of the chorda tympani nerve (CTN) origin on the round window (RW) accessibility during pediatric cochlear implantation (CI). We also tried to validate the radiologic method to measure the length between the origin of the CTN from the facial nerve to the stylomastoid foramen (CF-SM). STUDY DESIGN: It was a prospective observational case-series study. SETTINGS: The included CI surgeries were performed at tertiary referral institutions from November 2018 to August 2021. SUBJECTS: We included 146 pediatric patients who were candidates for CI. INTERVENTION: We measured the CF-SM length in the parasagittal cut of the preoperative high-resolution computed tomography. We also classified the intraoperative RW according to the accessibility through the ordinary posterior tympanotomy approach into accessible or inaccessible. MAIN OUTCOME MEASURE: We correlated the preoperative radiologic CF-SM length with the intraoperative RW accessibility. RESULTS: The radiologic CF-SM length ranged from 2.9 to 7.4 mm with a mean of 4.9 ± 1.03 mm. The RW was accessible in 107 patients and inaccessible in 39 patients. Spearman's correlation coefficient revealed a significant relationship between the location of CTN origin and the RW accessibility as the p value was less than 0.0001. CONCLUSIONS: We found a precise method to measure the CF-SM length in the parasagittal cut of the high-resolution computed tomography. We also found a significant impact of the location of the CTN origin on intraoperative RW accessibility. The radiologic CF-SM length of more than 5.4 mm had a powerful prediction capability of the RW inaccessibility.

A new method of preoperative assessment of correct electrode array alignment based on post-operative measurements in a cochlear implanted cohort.

PURPOSE: During cochlear implantation surgery, a range of complications may occur such as tip fold-over. We recently developed a method to estimate the insertion orientation of the electrode array. The aim of the study was to determine the optimal angle of orientation in a cohort of cochlear implanted patients. METHODS: On eighty-five CT scans (80 uncomplicated insertions and 5 cases with tip fold-over), location of the electrode array's Insertion Guide (IG), Orientation marker (OM) and two easily identifiable landmarks (the round window (RW) and the incus short process (ISP)) were manually marked. The angle enclosed by ISP-RW line and the Cochlear™ Slim Modiolar electrode array's OM line determined the electrode array insertion angle. RESULTS: The average insertion angle was 45.0-47.2° ± 10.4-12° SD and was validated with 98% confidence interval. Based on the measurements obtained, patients' sex and age had no impact on the size of this angle. Although the angles of the tip fold-over cases (44.9°, 46.9°, 34.2°, 54.3°, 55.9°) fell within this average range, the further it diverted from the average it increased the likelihood for tip fold-over. CONCLUSION: Electrode array insertion in the individually calculated angle relative to the visible incus short process provides a useful guide for the surgeon when aiming for the optimal angle, and potentially enhances good surgical outcomes. Our results show that factors other than the orientation angle may additionally contribute to failures in implantation when the Slim Modiolar electrode is used.

Cost-Effectiveness of Intraoperative CT Scanning in Cochlear Implantation in Fee-for-Service and Bundled Payment Models.

OBJECTIVE: Electrode array tip fold-over is a complication of cochlear implant surgery that results in poor hearing outcomes and often leads to revision surgery. However, tip fold-over can be corrected immediately if identified through intraoperative computed tomography, which also potentially provides information about final intracochlear positioning. Our objective was to provide the first economic analysis of intraoperative computed tomography by generating models in fee-for-service and bundled payment reimbursement structures of payer and institutional cost-effectiveness of this technology used in cochlear implantation over 1, 5, and 10-year time periods. METHODS: Cost data specific to a commerically available intraoperative computed tomography machine was obtained from the manufacturer, Xoran Technologies. Institutional tip fold-over rate was obtained from already published data. Medicare reimbursement rate for cochlear implantation was obtained from institutional accountants. Private payer reimbursement for and cost of revision cochlear implantation were estimated based on available data. RESULTS AND CONCLUSION: At large volume centers, cost-effectiveness of this technology is possible in both fee-for-service and bundled payment reimbursement structures at various time points dependent on payer mix. Even low volume cochlear implantation centers (<150 per year) can financially benefit from intraoperative computed tomography in bundled payment models at 5- and 10-year periods regardless of payer mix. This model demonstrates key factors at play in determining cost-effectiveness of this technology including institutional factors and payer type and suggests this technology can align incentives both to improve patient care and outcomes with institutional and payer financial well-being.

Development and Evaluation of a Language-Independent Test of Auditory Discrimination for Referrals for Cochlear Implant Candidacy Assessment.

OBJECTIVES: The purpose of this study was to (1) develop a Language-independent Test of Auditory Discrimination (LIT-AD) between speech sounds so that people with hearing loss who derive limited speech perception benefits from hearing aids (HAs) may be identified for consideration of cochlear implantation and (2) examine the relationship between the scores for the new discrimination test and those of a standard sentence test for adults wearing either HAs or cochlear implants (CIs). DESIGN: The test measures the ability of the listener to correctly discriminate pairs of nonsense syllables, presented as sequential triplets in an odd-one-out format, implemented as a game-based software tool for self-administration using a tablet computer. Stage 1 included first a review of phonemic inventories in the 40 most common languages in the world to select the consonants and vowels. Second, discrimination testing of 50 users of CIs at several signal to noise ratios (SNRs) was carried out to generate psychometric functions. These were used to calculate the corrections in SNR for each consonant-pair and vowel combination required to equalize difficulty across items. Third, all items were individually equalized in difficulty and the overall difficulty set. Stage 2 involved the validation of the LIT-AD in English-speaking listeners by comparing discrimination scores with performance in a standard sentence test. Forty-one users of HAs and 40 users of CIs were assessed. Correlation analyses were conducted to examine test-retest reliability and the relationship between performance in the two tests. Multiple regression analyses were used to examine the relationship between demographic characteristics and performance in the LIT-AD. The scores of the CI users were used to estimate the probability of superior performance with CIs for a non-CI user having a given LIT-AD score and duration of hearing loss. RESULTS: The LIT-AD comprises 81 pairs of vowel-consonant-vowel syllables that were equalized in difficulty to discriminate. The test can be self-administered on a tablet computer, and it takes about 10 min to complete. The software automatically scores the responses and gives an overall score and a list of confusable items as output. There was good test-retest reliability. On average, higher LIT-AD discrimination scores were associated with better sentence perception for users of HAs (r = -0.54, p <0.001) and users of CIs (r = -0.73, p <0.001). The probability of superior performance with CIs for a certain LIT-AD score was estimated, after allowing for the effect of duration of hearing loss. CONCLUSIONS: The LIT-AD could increase access to CIs by screening for those who obtain limited benefits from HAs to facilitate timely referrals for CI candidacy evaluation. The test results can be used to provide patients and professionals with practical information about the probability of potential benefits for speech perception from cochlear implantation. The test will need to be evaluated for speakers of languages other than English to facilitate adoption in different countries.

Assessment of Receptive and Expressive Language Skills Among Young Children With Prelingual Single-Sided Deafness Managed With Early Cochlear Implantation.

Importance: Pediatric single-sided deafness (SSD) can seriously affect development, causing impaired spatial hearing skills, speech-language delays, and academic underachievement. Early cochlear implantation likely improves hearing-related outcomes, but its association with language development remains unclear. Objective: To investigate whether early cochlear implantation is associated with language outcomes for children with prelingual SSD. Design, Setting, and Participants: The Cochlear Implant for Children and One Deaf Ear study was initiated in 2015 and recruited participants at 4 academic hospitals in Flanders, Belgium, through 2019. This cohort study included 3 groups of children aged 2 to 5 years: children with SSD and a cochlear implant, children with SSD without a cochlear implant, and a control group with normal hearing. Language and hearing skills were assessed 1 to 2 times per year until the age of 10 years. Study completion rates were high (82%). Data analysis was performed from October to December 2020. Exposure: Unilateral cochlear implant. Main Outcomes and Measures: Longitudinal vocabulary, grammar, and receptive language scores. The implanted group was hypothesized to outperform the nonimplanted group on all language tests. Results: During the recruitment period, 47 children with prelingual SSD without additional disabilities were identified at the participating hospitals. Fifteen of the 34 children with an intact auditory nerve received a cochlear implant (44%, convenience sample). Sixteen of the remaining children were enrolled in the SSD control group (50%). Data from 61 children (mean [SD] age at the time of enrollment, 2.08 [1.34] years; 26 girls [42%]) were included in the analysis: 15 children with SSD and a cochlear implant, 16 children with SSD without a cochlear implant, and 30 children with normal hearing. Children with SSD and a cochlear implant performed in line with their peers with normal hearing with regard to grammar. In contrast, children with SSD without a cochlear implant had worse grammar scores than the group with implants (-0.76; 95% CI, -0.31 to -1.21; P = .004) and the group with normal hearing (-0.53; 95% CI, -0.91 to -0.15; P = .02). The 3 groups had similar vocabulary and receptive language abilities. Conclusions and Relevance: These findings suggest that early cochlear implantation is associated with normal grammar development in young children with prelingual SSD. Although further follow-up will reveal the long-term outcomes of the cochlear implant for other skills, the current results will help clinicians and policy makers identify the best treatment option for these children.