Unilateral Cochlear Implantation Research Articles

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

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

Longitudinal Effects of Simultaneous and Sequential Bilateral Cochlear Implantation on Cortical Auditory-Evoked Potentials Recorded at Cz in a Large Cohort of Children.

Auditory development after bilateral cochlear implantation in children has been measured using source localization of multi-channel late latency responses. It is not clear, however, whether this development can be tracked using a more clinically feasible method of recording from one active recording electrode placed at mid-line center of the head (Cz). In this prospective cohort study, cortical auditory-evoked potential responses (CAEPs) were recorded from Cz referenced to each earlobe (Cz-CAEP) from 222 children with bilateral cochlear implant (CI); 128 (mean ± SD age: 2.78 ± 3.30 years) received both CIs in the same surgery (simultaneous group) and 94 (aged 7.72 ± 4.45 years) received a second CI after 4.21 ± 2.98 years of unilateral CI use. We sought to (1) identify cortical development over the first couple of years of bilateral CI use; (2) measure known asymmetries in auditory development between the CIs; and (3) detect the effects of bilateral rather than unilateral CI use. 4556 Cz-CAEPs were recorded across the cohort over 33.50 ± 7.67 months duration of bilateral CI use. Given concerns related to peak picking, amplitude areas were measured across two response time windows (50 to 199 ms and 200 to 400 ms). Results indicated that small response amplitudes occur at initial CI use and amplitudes increase in the negative or positive direction rapidly over the first months of CI use in both time windows. Asymmetries between Cz-CAEPs evoked by each CI were found in the sequential group and reduced with bilateral CI use, particularly in the first time window; these differences increased with longer inter-implant delay. Bilaterally evoked Cz-CAEPs were larger in amplitude than unilateral responses from either CI in the simultaneous group. In the sequential group, bilateral responses were similar to responses from the first implanted side but increased in relative amplitude with bilateral CI use. The Cz-CAEP measures were not able to predict asymmetries or bilateral benefits in speech perception measures. The Cz-CAEP was able to indicate cortical detection of CI input and showed gross morphological changes with bilateral CI use. Findings indicate Cz-CAEPs can be used to identify gross changes in auditory development in children with bilateral CIs, but they are less sensitive to tracking the remaining abnormalities that are measured by multi-channel CAEPs and speech perception testing.

The Impact of the COVID-19 Lockdown on Quality of Life in Adult Cochlear Implant Users: A Survey Study.

Background: The COVID-19 pandemic rapidly spread through Europe in the first months of 2020. On the 9th of March 2020, the Italian government ordered a national lock-down. The study’s objectives were: to investigate the effect of lockdown on CI users; and to detect the difference in the perception of discomfort existing between unilateral cochlear implant (UCI) users and bilateral cochlear implant (BCI) users, due to the lockdown experience. Methods: A 17-item, web-based, anonymous online survey was administered to 57 CI users, exploring hearing performance, emotions, practical issues, behavior, and tinnitus. Participation in the study was voluntary. Results: all CI users obtained an abnormal score in all questionnaire themes. For the emotion theme and the practical issue theme, the age range 61–90 showed a significant difference between UCI and BCI users in favor of BCI users (emotion theme: UCI mean = 3.9, BCI mean = 2.3, p = 0.0138; practical issues: UCI mean = 4, BCI mean = 3, p = 0.0031). Conclusions: CI users experienced the lockdown negatively as regards behavior, emotions, hearing performance, and in practical issues. CI subjects with UCI in old age suffered more from the experience of lockdown than subjects with BCI in the same age, with regards to emotions and practical issues.

Minimally invasive surgical techniques in vestibular function preservation in patients with cochlear implants.

BackgroundCochlear implantation (CI) is an effective and successful method of treating individuals with severe-to-profound sensorineural hearing loss (SNHL). Coupled with it’s great clinical effectiveness, there is a risk of vestibular damage. With recent advances in surgical approach, modified electrode arrays and other surgical techniques, the potential of hearing preservation (HP) has emerged, in order to preserve the inner ear function. These techniques may also lead to less vestibular damage. However, a systematic study on this at different follow-ups after CI surgery has not been documented before.AimsTo investigate changes of vestibular function systematically in recipients at short and long follow-ups after a minimally invasive CI surgery.MethodsIn this retrospective study, 72 patients (72 ears) with minimally invasive CI were recruited. All participants selected had bilateral SNHL and pre-operative residual hearing (RH) and underwent unilateral CI. They were treated to comprehensive care. All patients underwent vestibular function tests 5 days prior to CI. During the post-operative period, follow-up tests were performed at 1, 3, 6, 9, and 12 months. The contemporaneous results of caloric, cervical vestibular-evoked myogenic potential (cVEMP), ocular vestibular-evoked myogenic potential (oVEMP), and video head impulse (vHIT) tests were followed together longitudinally.ResultsOn the implanted side, the percent fail rate of caloric test was significantly higher than that of vHIT at 1, 3, and 9 months post-operatively (p < 0.05); the percent fail rate of oVEMP was higher than vHIT of superior semicircular canal (SSC), posterior semicircular canal (PSC), or horizontal semicircular canal (HSC) at 1, 3, and 9 months (p < 0.05); at 3 and 9 months, the percent fail rate of cVEMP was higher than that of SSC and PSC (p < 0.05). There were no significant differences in the percent fail rates among all tests at 6 and 12 months post-CI (p > 0.05). The percent fail rates showed decreased trends in caloric (p = 0.319) and HSC tested by vHIT (p = 0.328) from 1–3 to 6–12 months post-operatively. There was no significant difference in cVEMP between 1–3 and 6–12 months (p = 0.597). No significant differences on percent fail rates of cVEMP and oVEMP between short- and long-terms post-CI were found in the same subjects (p > 0.05). Before surgery, the abnormal cVEMP and oVEMP response rates were both lower in patients with enlarged vestibular aqueduct (EVA) than patients with a normal cochlea (p = 0.001, 0.018, respectively).ConclusionThe short- and long-term impacts on the vestibular function from minimally invasive CI surgery was explored. Most of the vestibular functions can be preserved with no damage discrepancy among the otolith and three semicircular canal functions at 12 months post-CI. Interestingly, a similar pattern of changes in vestibular function was found during the early and the later stages of recovery after surgery.

Gamma-Band Modulation in Parietal Area as the Electroencephalographic Signature for Performance in Auditory-Verbal Working Memory: An Exploratory Pilot Study in Hearing and Unilateral Cochlear Implant Children.

This pilot study investigates the neurophysiological patterns of visual and auditory verbal working memory (VWM) in unilateral cochlear implant users (UCIs). We compared the task-related electroencephalogram (EEG) power spectral density of 7- to 13-year-old UCIs (n = 7) with a hearing control group (HC, n = 10) during the execution of a three-level n-back task with auditory and visual verbal (letters) stimuli. Performances improved as memory load decreased regardless of sensory modality (SM) and group factors. Theta EEG activation over the frontal area was proportionally influenced by task level; the left hemisphere (LH) showed greater activation in the gamma band, suggesting lateralization of VWM function regardless of SM. However, HCs showed stronger activation patterns in the LH than UCIs regardless of SM and in the parietal area (PA) during the most challenging audio condition. Linear regressions for gamma activation in the PA suggest the presence of a pattern-supporting auditory VWM only in HCs. Our findings seem to recognize gamma activation in the PA as the signature of effective auditory VWM. These results, although preliminary, highlight this EEG pattern as a possible cause of the variability found in VWM outcomes in deaf children, opening up new possibilities for interdisciplinary research and rehabilitation intervention.

Acceptable Noise Level in Children with Unilateral Cochlear Implant and Bimodal Hearing

Background and Aim: Difficulty in perception of speech in noise is one of the main complaints of hearing-impaired people. Due to profound hearing loss in cochlear implant (CI) users, they need higher signal-to-noise ratio for a better perception. Bimodal fitting is a preferred way for CI users because it prevents auditory nerve degeneration, is a complement of frequency range at the opposite ear, an is less invasive to provide binaural hearing. Acceptable noise level (ANL), as a reliable test to assess noise tolerance, has not yet been used in comparing children with bimodal hearing and CI. This study aimed to determine whether bimodal fitting can help CI children tolerate more noise.&#x0D; Methods: This descriptive-analytical study was conducted on 13 children with unilateral CI and bimodal hearing. Audiometry test was performed at aided and non-aided conditions. Then, their noise tolerance was assessed by the Persian version of ANL test.&#x0D; Results: Bimodal hearing resulted in statistically significant increase in ANL. The mean of ANL at unilateral CI and bimodal hearing conditions were 6.15±2.90 and 4.77±1.70, respectively.&#x0D; Conclusion: Bimodal fitting lead to more noise tolerance in unilateral CI children due to the combination of binaural summation and binaural release from masking.&#x0D; Keywords: Acceptable noise level; cochlear implant; hearing aid; bimodal hearing; profound hearing loss; binaural hearing

Can Video Head Impulse Test Determine the Early Effect of Cochlear Implantation on the Semicircular Canals Function?

Background and Aim: Although cochlear implantation (CI) is a safe surgical procedure for severe to profound sensorineural hearing loss (SNHL) but, due to the embryological and anatomical connection between the vestibular and cochlear structures, vestibular dysfunction may occur after CI. Video head impulse test (vHIT) is a reliable test for assessing the function of semicircular canals (SCCs). This study aimed to determine the early effect of CI on SCCs function, by comparing pre- and post-operative vHIT results. Methods: In this cross-sectional study, participants were 22 adults with SNHL scheduled for unilateral CI in the right ear and 22 age-matched healthy subjects as a control group. The vHIT was conducted before and two weeks after CI. Results: The mean vHIT gains in the SNHL group were significantly lower than in controls, with a large effect size. Furthermore, the mean vHIT gains in the right lateral SCCs (p&lt;0.001) and right anterior SCCs (p=0.003) were significantly reduced after CI, compared to the gain values before CI, with a large pooled effect size. However, these differences were not statistically significant for the right posterior SCCs. The comparison of vHIT gains in the non- implanted ear showed no statistically significant difference between pre- and post-operative phases. Conclusion: The vHIT is a useful clinical method to detect the early effects of CI on the function of SCCs. These effects are more obvious in the lateral and superior SCCs in the implanted ear. Keywords: Cochlear implantation; semicircular canals; video head impulse test

Listening Effort in Prelingual Cochlear Implant Recipients: Effects of Spectral and Temporal Auditory Processing and Contralateral Acoustic Hearing.

Considering the impact of listening effort (LE) on auditory perception, attention, and memory, it is a significant aspect in the daily hearing experiences of cochlear implant (CI) recipients. Reduced spectral and temporal information on an acoustic signal can make listening more difficult; as a result, it is important to understand the relationship between LE and spectral and temporal auditory processing capacities in CI receivers. This study used spectral ripple discrimination and temporal modulation transfer function to evaluate 20 prelingually deafened and early implanted CI recipients. The speech perception in noise test (primary) and the digit recall task (DRT-secondary) were used to assess LE using the dual-task paradigm. To assess the effects of acoustic hearing, contralateral acoustic hearing thresholds between 125 Hz and 8 kHz with a hearing aid were also acquired. To examine the relationship between the research variables, correlation coefficients were generated. Furthermore, the Mann-Whitney U test was used to compare unilateral and bimodal users. There was a statistically significant correlation between LE and spectral ripple discrimination (r = 0.56; p = 0.011), 125 Hz (r = 0.51; p = 0.020), 250 Hz (r = 0.48; p = 0.030), 500 Hz (r = 0.45; p = 0.045), 1,000 Hz (r = 0.51; p = 0.023), 2000 Hz (r = 0.48; p = 0.031), and 4,000 Hz (r = 0.48; p = 0.031), whereas no statistically significant correlations were observed between temporal modulation transfer function in four frequencies and LE. There was no statistically significant difference between unilateral and bimodal CI recipients ( p > 0.05). As a result of the improved signal-to-noise ratio in the auditory environment, CI users with better spectral resolutions and acoustic hearing have a reduced LE. On the other hand, temporal auditory processing, as measured by temporal modulation detection, does not contribute to the LE.

Further Evidence for Individual Ear Consideration in Cochlear Implant Candidacy Evaluation.

To report speech outcomes after cochlear implantation (CI) for asymmetric hearing loss (AHL) and assess the influence of contralateral hearing. Retrospective review. Tertiary referral center. One hundred eighty-eight adults (mean age, 70 yr) undergoing CI for AHL from 2015 to 2020. Candidacy included pure-tone average (PTA) at least 70 dB hearing level and AzBio in quiet 60% or less in the implanted ear and AzBio in quiet greater than 40% in the contralateral ear. PTA; Consonant-Nucleus-Consonant (CNC) word, AzBio sentences scores; Speech, Spatial, and Qualities of Hearing Scale (SSQ). Mean preoperative PTA and AzBio in the implanted and contralateral ears were 85.2 and 68.1 dB hearing level and 24.7% and 69.2%, respectively. Mean CNC in the implanted ear increased from 18.3% preoperatively to 44.4% ( p < 0.0001) at 6 months and 49.3% ( p < 0.0001) at 12 months. Mean AzBio in the implanted ear improved from 24.7% preoperatively to 60.3% ( p < 0.0001) at 6 months and 64.3% ( p < 0.0001) at 12 months. Patients demonstrated significant improvement in all SSQ domains at 6 and 12 months. When comparing patients with preoperative contralateral AzBio greater than 60% versus 41% to 60%, no significant differences existed in postoperative CNC scores (6-mo: 47% versus 41%, p = 0.276; 12-mo: 51% versus 47%, p = 0.543). There were no significant differences in 6-month ( p = 0.936) or 12-month ( p = 0.792) CNC scores between patients with AHL (contralateral ear AzBio >40%) and 169 unilateral CI patients meeting the traditional Medicare criteria (contralateral ear AzBio ≤40%). CI recipients with AHL derive significant speech improvements, supporting individual ear consideration for CI candidacy and patient benefit outside of current Medicare criteria.

A Five-Year Update on the Profile of Adults Undergoing Cochlear Implant Evaluation and Surgery-Are We Doing Better?

To characterize the influence of expanding indications on the profile of adults undergoing cochlear implantation (CI) at a high-volume CI center. Retrospective review. Tertiary referral center. 774 adults undergoing CI evaluation from August 2015 to August 2020. Demographics; audiometry; speech recognition; speech, spatial, and qualities of hearing scale (SSQ-12). Of 745 (96.3%) patients qualifying for implantation, 642 (86.6%) pursued surgery. Median age at evaluation was 69 years; 56.3% were men; 88.2% were Caucasian. Median distance to our center was 95 miles. The majority (51.8%) had public insurance (Medicare, Medicaid), followed by private (47.8%) and military (0.4%). Mean PTA, CNC, and AzBio in quiet and noise for the ear to be implanted were 85.2 dB HL, 15.0%, and 19.2% and 3.5%, respectively. Hybrid/EAS criteria were met by 138 (18.5%) CI candidates, and 436 (77.0%) unilateral CI recipients had aidable contralateral hearing for bimodal hearing configurations. Younger age (odds ratio [OR], 0.96; 95% confidence interval, 0.93-0.99) and non-Caucasian race (OR, 6.95; 95% confidence interval, 3.22-14.98) predicted candidacy. Likelihood of surgery increased for Caucasian (OR, 8.08; 95% confidence interval, 4.85-13.47) and married (OR, 2.28; 95% confidence interval, 1.50-3.47) patients and decreased for those with public insurance (OR, 0.45; 95% confidence interval, 0.29-0.69). A lower SSQ-12 score predicted both candidacy and surgery. Despite expansions in criteria, speech understanding remained extremely low at CI evaluation. Younger age and non-Caucasian race predicted candidacy, and Caucasian, married patients with private insurance and lower SSQ scores were more likely to pursue surgery.

Prevalence of Endolymphatic Hydrops in Cochlear Implant Candidates with Idiopathic Profound Sensorineural Hearing Loss.

To determine the prevalence of endolymphatic hydrops (EH) in cochlear implant (CI) candidates with idiopathic profound sensorineural hearing loss (SNHL) and its influence on the preservation of audiovestibular function after cochlear implantation. Prospective case series. Tertiary referral center. CI candidates with idiopathic progressive SNHL, but without classic EH-associated symptoms. Delayed intravenous gadolinium-enhanced inner ear fluid-attenuated inversion recovery magnetic resonance imaging as well as pure-tone audiograms, video head impulse tests, and vestibular evoked myogenic potentials before and 4 weeks after cochlear implantation. Prevalence of EH before cochlear implantation, audiovestibular function before and after surgery in hydropic and nonhydropic ears. Thirty-two ears in 16 CI candidates were included. Nine ears (28%) with EH were detected. Although preoperative hearing thresholds, utricular function, and semicircular canal function were not different between the two groups, saccular function was reduced in hydropic ears. Ten subjects received a unilateral CI. Of these, 3 (30%) showed EH on the implanted side. There was no difference regarding postoperative hearing loss between the two groups, but the results point toward a higher vulnerability of hydropic ears with respect to loss of otolith function after cochlear implantation. This is the first study showing that EH can be assumed in about one third of CI candidates with idiopathic profound SNHL, but no classic EH-associated symptoms. Preliminary results suggest that EH has no influence on the preservation of cochlear function but could be a risk factor for loss of otolith function after cochlear implantation.

Phonological awareness and reading abilities in elementary-school students with severe-to-profound prelingual hearing loss and unilateral cochlear implants

BackgroundResearch findings on the reading outcomes of cochlear implants are inconsistent. Controversy was observed in the reading performance of implanted children, both in relation to hearing aid users and normally hearing children. This cross-sectional study aims to evaluate the phonological awareness and reading skills of school-aged, severe-to-profound, prelingually deafened children using cochlear implants and to identify any associations between these skills and age of implantation, language development, and the chosen side of implantation. Patients who met the selection criteria were assessed using standardized phonological awareness and reading tests, and their scores were compared to normative data.ResultsPatients’ average scores were significantly behind age-matched normative data. Phonological awareness was strongly correlated to reading skills, and both were positively correlated to language abilities. Age at implantation was not correlated to phonological skills yet it was positively correlated to reading scores for patients over 9 years old.ConclusionMany cochlear implanted children are still struggling with reading. Phonological development should be considered in the rehabilitation of this group of patients as it was found to be closely associated with reading proficiency.

Sound Localization in Unilateral Cochlear Implant Users

Purpose: Sound is localized by two ears. People with bilaterally severe-to-profound hearing loss may struggle to identify the direction of a sound if their hearing device delivers sound only one ear due to the loss of binaural advantage. The purpose of this study was to systematically investigate the sound localization performance of people with unilateral cochlear implant users. Methods: Ten unilateral cochlear implant users and 10 normal hearing adults participated in this study. Sound localization tests were conducted using five stimuli (speech, speech with noise, 500 Hz warble tone, 1 kHz warble tone, and 4 kHz warble tone) presented from eight loud-speakers. Correct responses and root- mean-square errors were obtained to investigate the localization performances and error patterns. Additional factors including the Korean-Speech Spatial and Qualities of Hearing Questionnaire were also analyzed. Results: Localization performance was significantly poor in the unilateral cochlear implant group showing polar patterns toward their hearing side. While the normal hearing group showed better localization for speech in quiet conditions compared to 500 Hz warble tone, the cochlear implant group did not show any statistical difference in performance across the stimuli due to their very poor performance. The Korean-Speech Spatial and Qualities of Hearing Questionnaire was associated with localization performance in limited conditions. Conclusion: The present study revealed that unilateral cochlear implant users correctly localize a sound at nearly chance levels. The Korean-Speech Spatial and Qualities of Hearing Questionnaire predict localization performance for unilateral cochlear implant users only for particular conditions.

Cochlear implants: Visual evoked potentials study

Cochlear implants (CIs) are a successful alternative in cases with severe-to-profound HL. In these individuals, visual cross-modal re-organization can occur because of hearing loss where the visual cortex will recruit auditory cortical areas for visual processing. ObjectivesThis work is designed to study visual evoked potentials (VEPs) in children fitted with CIs in comparison to normal hearing children. MethodThis work included 2 groups of children: Group I included 20 normal hearing children and study group included 25 children fitted with unilateral CIs. All cases were subjected to Thorough otological history. Check up on CIs performance using physical check and Aided sound field examination, ophthalmic examination and Pattern Visual Evoked Potentials (pVEPs). ResultsBoth groups showed no significant difference as regard age or sex. And both had normal ophthalmic examinations. Children of the study groups showed satisfactory aided response. As regard pVEPs, the study group showed significant higher P100 amplitude in comparison to the control group. ConclusionThis study showed that deafness could induced cortical organization in the visual cortex and not limited to the auditory cortex only.

Benefit of sequential bilateral cochlear implantation in children between 5 to 18 years old: A prospective cohort study.

To determine the benefit of sequential cochlear implantation after a long inter-implantation interval in children with bilateral deafness receiving their second implant between 5 and 18 years of age. Prospective cohort-study. Tertiary multicenter. 85 children with bilateral deafness and unilateral implantation receiving a contralateral cochlear implant at the age of 5 to 18 years. The primary outcomes were speech recognition in quiet and noise (CVC) scores. The secondary outcomes were language outcomes and subjective hearing abilities, all measured before and 12 months after sequential bilateral cochlear implantation. Medians of the paired data were compared using the Wilcoxon signed-rank test. Univariable linear regression analyses was used to analyze associations between variables and performance outcomes. A significant benefit was found for speech recognition in quiet (96% [89-98] vs 91% [85-96]; p < 0.01) and noise (65% [57-75] vs 54% [47-71]; p = 0.01) in the bilateral CI condition compared to unilateral (n = 75, excluded 10 non-users). No benefit was seen for language outcomes. The subjective sound quality score was statistically significant higher in bilateral compared to the unilateral CI condition. Pre-operative residual hearing level in the ear of the second implant, the inter-implant interval and age at time of second implantation was not significantly associated with performance scores. After 12 months of use, sequential bilateral cochlear implantation showed improved speech perception in quiet and noise and improved subjective sound quality outcomes in children despite a great inter-implantation interval (median of 8 years [range 1-16 years]).

Bone conducted vibration is an effective stimulus for otolith testing in cochlear implant patients.

BACKGROUND:Treatment with a cochlear implant (CI) poses the risk of inducing a behaviorally unmeasurable air-bone gap leading to false negative absence of cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) to air conducted sound (ACS).OBJECTIVE:To investigate VEMP response rates to ACS and bone conducted vibration (BCV) in CI patients and the applicability of the B81 transducer for BCV stimulation.METHODS:Prospective experimental study including unilateral CI patients, measuring cVEMPs and oVEMPs to ACS and to BCV, comparing response rates, signed asymmetry ratios, latencies, and amplitudes.RESULTS:Data of 13 CI patients (mean age 44±12 years) were analyzed. For the CI side, oVEMP and cVEMP response rates were significantly higher for BCV (77%cVEMP, 62%oVEMP) compared to ACS (23%cVEMP, 8%oVEMP). For the contralateral side, no difference between response rates to ACS (85%cVEMP, 69%oVEMP) and BCV (85%cVEMP, 77%oVEMP) was observed. Substantially higher asymmetries were observed for ACS (–88±23%for cVEMPs, –96±11%for oVEMPs) compared to BCV (–12±45%for cVEMPs, 4±74%for oVEMPs).CONCLUSIONS:BCV is an effective stimulus for VEMP testing in CI patients. The B81 is a feasible stimulator.

In an era of bilateral funding and changing criteria, when is unilateral cochlear implantation a better option?

Funding for paediatric bilateral cochlear implantation became available in Ireland in 2014. Prior to this, children eligible for cochlear implantation received a unilateral implant. To examine the cohort of children who received a unilateral cochlear implant in the 4year period following bilateral cochlear implantation funding becoming available. A clinical audit of all children implanted for the first time between July 2014 and July 2018. The unilaterally implanted children (n = 105) were divided into 3 groups according to whether they met the audiometric thresholds for implantation in neither ear (Group 1), one ear (Group 2) or both ears (Group 3). One year post operative functional outcomes were examined for all 3 groups. All 3 groups showed significant improvements in functional outcomes at 1year post op. To date, 20% of the unilaterally implanted children have proceeded to get a sequential CI, often where there was no change in audiological status. The number of children in Groups 1 and 2 highlighted how our decision making around cochlear implantation has changed in recent years. Unilateral cochlear implantation in certain circumstances is good practice, independent of the audiological profile when an experienced multi-disciplinary team (MDT) is involved in the decision making process. Decision making using a holistic model approach is key, including involving the parent/carer and, where appropriate, the child/teenager themselves. A staged bilateral cochlear implant is also a good option, where careful monitoring and support for the first implant has resulted in positive outcomes.

Bimodal Cochlear Implant Processing based on Assisted Hearing algorithms with CCi-MOBILE: an open-source research platform.

While speech understanding for cochlear implant (CI) and Hearing aid (HA) users in quiet is relatively effective, listeners experience difficulty in identification of speakers and sound location. Previous studies have reported improved localization and better speech perception when the unilateral CI is coupled with a HA in the contralateral ear. This is referred to as bimodal presentation of speech or electric and acoustic stimulation (EAS). Various CI research interfaces developed by either academic or industry sponsored research teams support proposed signal processing and psychoacoustic investigations but have limited ability to efficiently validate bimodal algorithms. Platforms that support bimodal testing (CI and HA) are either not portable or only provide limited features due to proprietary parameters/routines. CCi-MOBILE, an open-source, portable signal processing research device, developed by UT-Dallas, enables electric and acoustic stimulations simultaneously, thus providing researchers the opportunity to explore new technology and scientific paradigms for the hearing impaired. In the present work, we provide verification and implementation of synchronized bimodal (electric-acoustic) output in an authenticated and efficient manner to support sound and acoustic localization algorithms for experimental investigations.

Impact of Expanding Eligibility Criteria for Cochlear Implantation - Dynamic Modeling Study.

Eligibility criteria for cochlear implantation (CI) are shifting due to technological and surgical improvements. The aim of this study was to explore the impact of further expanding unilateral CI criteria in those with severe hearing loss (HL) (61-80 dBHL) in terms of number of CI recipients, costs, quality of life, and cost-effectiveness. A dynamic population-based Markov model was constructed mimicking the Dutch population in three age categories over a period of 20 years. Health states included severe HL (61-80 dBHL), profound HL (>81 dBHL), CI recipients, and no-CI recipients. Model parameters were based on published literature, (national) databases, expert opinion, and model calibration. If persons with severe HL would qualify and opt for CI similar to those with profound HL now, this would lead to a 6-7 times increase of new CI recipients and an associated increase in costs (€550million) and QALYs (54.000) over a 20-year period (incremental cost utility ratio: 10.771 euros/QALY [2.5-97.5 percentiles: 1.252-23.171]). One-way-sensitivity analysis indicated that model outcomes were most sensitive to regaining employment, utility associated with having a CI, and costs of surgery and testing. Our findings suggest that expanding eligibility for CI to persons with severe HL could be a cost-effective use of resources. Clearly, however, it would require a significant increase in diagnostic, operative, and rehabilitative capacity. Our quantitative estimates can serve as a basis for a wider societal deliberation on the question whether such an increase can and should be pursued. NA Laryngoscope, 133:924-932, 2023.

Adult Cochlear Implantation Under Local Anesthesia and Conscious Sedation with Dexmedetomidine: Efficacy and a Method to Interact with the Conscious and Cooperative Patient.

This study describes the efficacy of cochlear implantation under local anesthesia with conscious sedation with dexmedetomi- dine in adult patients and proposes a method to communicate with the conscious and cooperative patient intraoperatively. This less invasive anesthetic procedure is suitable for patients with comorbidities preventing general anesthesia. Unilateral cochlear implantation with Oticon Medical systems was performed in 10 adult patients with comorbidities preventing general anesthesia. Classical cochlear implantation was performed under local anesthesia and conscious sedation with dexmedetomidine. Cue cards were used to support intraoperative dialogue. Outcome measures were intraoperative adverse events, patient perceptions, as well as post- operative completions measured with a questionnaire. The procedure was successful for all 10 patients. Dexmedetomidine lead to rapid and successful conscious sedation and no case of high blood pressure or aggravation of comorbidities was noted. Stapedial reflex measurements led to reliable thresholds. The usage of the cue cards was successful: patients were able to read the cue cards and thereby the medical team could inform the patients of surgical progress and ask the patients questions. Cochlear implantation and intraoperative dialogue with the conscious and cooperative patient is possible. The main advantage of the anesthetic procedure is the reduction in intra- and postoperative complications. Further, expected benefits include a less invasive procedure, the conscious state of the patient which enables the recording of auditory perception, and the absence of nonauditory percepts such as facial nerve stimulation during implant stimulation, a shorter surgical duration, and lower-associated costs.