[Cochlear implantation - Adverse effects on the cochlea and the vestibular organ]. / Cochlea-Implantation.

Cochlear implantation is the treatment of choice for patients with profound hearing loss and deafness. At the same time, inserting a cochlear implant (CI) leaves damage to the inner ear. The preservation of inner ear structure and function has become a central issue in CI surgery. The reasons for this are i) electroacoustic stimulation (EAS), i.e., the option of joint stimulation by a hearing aid and a CI; ii) an improved audiologic outcome in electric-only stimulation; iii) the preservation of structures and residual hearing for potential future therapy options; and iv) the avoidance of side effects, such as vertigo. The exact mechanisms that determine the extent of damage to the inner ear and which factors contribute to preservation of residual hearing are not yet fully understood. In addition to the surgical technique, electrode selection may play a role. This article provides an overview of what is known about the direct and indirect adverse effects of cochlear implantation on the inner ear, of the methods available to monitor inner ear function during cochlear implantation, and of the focus of future research on preservation of inner ear structure and function.

Optimizing Location of Subdermal Recording Electrodes for Intraoperative Facial Nerve Monitoring.

OBJECTIVE: The purpose of this study is to determine if different facial muscle groups demonstrate different responses to facial nerve stimulation, the results of which could potentially improve intraoperative facial nerve monitoring (IOFNM). METHODS: IOFNM data were prospectively collected from patients undergoing cochlear implantation. At different stages of nerve exposure, three sites were stimulated using a monopolar pulse. Peak electromyography (EMG) amplitude (µV) in four muscle groups innervated by four different branches of the facial nerve (frontalis-temporal, inferior orbicularis oculi-zygomatic, superior oribularis oris-buccal, and mentalis-marginal mandibular) were recorded. RESULTS: A total of 279 peak EMG amplitudes were recorded in 93 patients. At all three stimulating sites, the zygomatic branch mean peak EMG amplitudes were statistically greater than those of the temporal, buccal, and marginal mandibular branches (P < .05). At stimulating Site C, the marginal mandibular branch mean peak EMG was stronger than the temporal or buccal branches (P < .05). Of the 279 stimulations, the zygomatic branch demonstrated the highest amplitude in 128 (45.9%) trials, followed by the marginal mandibular branch (22.2%). CONCLUSIONS: When utilized, IOFNM should be performed with at least two electrodes, one of which is placed in the orbicularis oculi muscles and the other in the mentalis muscle. However, there is wide variability between patients. As such, in cases of suspected variant nerve anatomy or increased risk of injury (intradural procedures), surgeons should consider using more than two recording electrodes, with at least one in the orbicularis oculi muscle. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2329-E2334, 2021.

Cochlear Implantation Under Local Anesthesia With Conscious Sedation in the Elderly: First 100 Cases.

OBJECTIVE: To report the outcomes on a large series of elderly patients who underwent cochlear implantation (CI) surgery under local anesthesia with conscious sedation (LA-CS). METHODS: Retrospective chart review on 100 consecutive elderly patients (> 65 years) who underwent CI with LA-CS at a tertiary care center between August 2013 and January 2020. An age-matched control group of 50 patients who underwent CI with general anesthesia (GA) are used for comparison. Outcomes measured included time in the operating room, time in the postanesthesia care unit (PACU), and rate of adverse events. RESULTS: Cochlear implant surgery under LA-CS was successfully performed in 99 (99%) patients. One patient requiring conversion to GA intraoperatively. No patients in the LA-CS group experienced cardiopulmonary adverse events; however, three patients (6%) in the GA group experienced minor events including atrial fibrillation and/or demand ischemia. Overnight observation in the hospital due to postoperative medical concerns or prolonged wake-up from anesthesia was required in one patient (1%) from the LA-CS cohort and 12 patients (24%) from the GA cohort. Perioperative adverse events exclusive to the LA-CS group included severe intraoperative vertigo (8%), temporary facial nerve paresis (3%), and wound infection (1%). The average amount of time spent in the operating room was 37 minutes less for procedures performed under LA-CS compared to GA (P < .05). The average amount of time in recovery was similar for both groups (P > .05). CONCLUSION: Cochlear implant surgery under LA-CS offers many benefits and is a safe, feasible, and cost-effective alternative to GA when performed by experienced CI surgeons. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E946-E951, 2021.

Perception of lexical stress cued by low-frequency pitch and insights into speech perception in noise for cochlear implant users and normal hearing adults.

PURPOSE: Cochlear implant (CI) users show great difficulty for understanding speech in noise and this fact may partly stem from their poor low-frequency (LF) pitch perception and temporal fine structure (TFS) processing. Clinical assessment of pitch perception is usually based on non-speech tasks. However, linguistically relevant contexts such as lexical stress may better reflect the role of pitch in speech perception, especially for everyday speech where background noise is inevitable. Hence, the study aimed to assess perception of lexical stress cued by LF pitch and TFS cues for CI and normal hearing (NH) listeners, and to investigate relationships with speech perception in noise. METHODS: The low-pass-filtered Word Stress Pattern (WSP-LPF) test was used to evaluate perception of lexical stress cued by LF pitch. Speech perception was assessed with the sentence test with adaptive randomized roving level (STARR) test which presented everyday sentences at low, medium, and high levels in a fluctuating noise to estimate a Speech Reception Threshold. This new test intended to give a realistic estimate for real-world listening. RESULTS: Median WSP-LPF scores in NH (N = 18) and CI listeners (N = 18) were 12.0 Hz and 67.0 Hz, respectively. The corresponding STARR scores were - 9.1 dB and 17.3 dB. Group differences were statistically significant (p < 0.001). Analysis showed significant positive correlations for NH (rs = 0.50) and CI listeners (rs = 0.60). CONCLUSIONS: Present findings reveal stronger correlations than previous studies using non-speech materials, supporting that CI listeners' poor speech perception in noise might be strongly associated with their inability for LF pitch perception and TFS processing.

Effect on vestibular function of cochlear implantation by partial deafness treatment-electro acoustic stimulation (PDT-EAS).

PURPOSE: Although the cochlear implantation procedure does not interfere with vestibular structures directly, both the vestibulum and the cochlea share the same inner ear fluid space, and this fluid may be responsible for transferring possibly damaging forces from one to the other. The purpose of the study is to assess postoperative vestibular function after partial deafness treatment-electro-acoustic stimulation (PDT-EAS) cochlear implantation. METHODS: Fifty-five patients were included in the study (30 females, 25 males, age 11-80, mean 41.8 ± 19.35). cVEMP and oVEMP were performed preoperatively and 1-3 months after cochlear implantation. Caloric and vHIT tests were conducted preoperatively and 4-6 months after cochlear implantation. RESULTS: Our study shows that, based on a wide range of electrodes, use of PDT-EAS is protective in terms of preserving vestibular function. It gives a rate of saccular damage of 15.79%, utricular damage of 19.04%, and a horizontal semicircular canal response reduction of 15.79%. CONCLUSIONS: PDT-EAS is protective in terms of preserving vestibular function. Nevertheless, it should be emphasized that the risk of vestibular damage cannot be totally eliminated even when hearing preservation techniques are adopted.

Intracochlear tPA infusion may reduce fibrosis caused by cochlear implantation surgery.

BACKGROUND: Experiments show that the extent of ongoing fibrotic change within the cochlea can be determined by the volume and pattern of bleeding within the first 24 h following cochlear implantation. Tissue-type plasminogen activator (tPA) is effective at reducing thrombus volume when administered both within and external to the systemic circulation. AIMS/OBJECTIVES: To determine if tPA delivered into the scala tympani immediately following implantation will reduce thrombus volume within the lower basal turn of the cochlea. MATERIALS AND METHODS: Guinea pigs were implanted with either 'soft' or 'hard' arrays and administered tPA or saline via an intra-cochlear infusion immediately after implantation. Hearing was checked prior to, and 2 weeks after implantation. Cochleae were then harvested and imaged. RESULTS: Animals implanted with 'soft' arrays had 4.2% less tissue response compared with animals implanted with 'hard' arrays. In animals receiving 'soft' arrays, tPA reduced the volume of tissue response (measured by the percentage of the lower basal turn of the scala tympani occupied by tissue response) compared with saline. CONCLUSIONS AND SIGNIFICANCE: tPA may be effective in reducing the overall volume of tissue response in routine 'soft' cochlear implantation and may have a greater effect in the event of significant surgical trauma.

Tinnitus Suppression in Cochlear Implant Patients Using a Sound Therapy App.

PURPOSE: The use of acoustic stimuli to reduce the prominence of tinnitus has been used for decades. Counseling and tinnitus sound therapy options are not currently widespread for cochlear implant (CI) users. The goal of this study was to determine whether tinnitus therapy sounds created for individuals with acoustic hearing may also benefit CI users. METHOD: Sixteen sounds from the ReSound Relief app (Version 3.0) were selected for the study. Sixteen participants were asked to rate the overall acceptability of each sound and to write the description of the sound they perceived. Sounds were streamed from an Apple™ iPod (6th generation) to the CI using a Cochlear™ Wireless Mini Microphone 2+. Thirteen participants then completed a 5-min trial where they rated their pretrial and posttrial tinnitus and the acceptability of a subset of preferred sounds. Ten out of these 13 participants completed a 2-week home trial with a preferred sound after which they answered an online tinnitus questionnaire and rated the effectiveness of the sound therapy. RESULTS: Individual differences were large. Results from the 5-min trial showed that sounds perceived as rain, music, and waves were rated the most acceptable. For all of the participants, the posttrial tinnitus loudness rating was lower than the pretrial rating, with some participants experiencing greater difference in their tinnitus loudness than others. At the end of the 2-week home trial, 3 of 10 participants rated the effectiveness of sound therapy 70% or higher. CONCLUSION: The results suggest that the use of tinnitus therapy sounds delivered through a CI can be acceptable and provides relief for some tinnitus sufferers.

Music complexity prediction for cochlear implant listeners based on a feature-based linear regression model.

This paper presents a model for predicting music complexity as perceived by cochlear implant (CI) users. To this end, 10 CI users and 19 normal-hearing (NH) listeners rated 12 selected music pieces on a bipolar music complexity scale and 5 other perception-related scales. The results indicate statistically significant differences in the ratings between CI and NH listeners. In particular, the ratings among different scales were significantly correlated for CI users, which hints at a common, hidden scale. The median complexity ratings by CI listeners and features accounting for high-frequency energy, spectral center of gravity, spectral bandwidth, and roughness were used to train a linear principal component regression model for an average CI user. The model was evaluated by means of cross-validation and using an independent database of processed chamber music signals for which music preferences scores by CI users were available. The predictions indicate a clear linear relationship with the preference scores, confirming the negative correlation between music complexity and music preference for CI users found in previous studies. The proposed model is a first step toward an instrumental evaluation procedure in the emerging field of music processing for CIs.

Neural Processing of Musical and Vocal Emotions Through Cochlear Implants Simulation.

Cochlear implants (CIs) partially restore the sense of hearing in the deaf. However, the ability to recognize emotions in speech and music is reduced due to the implant's electrical signal limitations and the patient's altered neural pathways. Electrophysiological correlations of these limitations are not yet well established. Here we aimed to characterize the effect of CIs on auditory emotion processing and, for the first time, directly compare vocal and musical emotion processing through a CI-simulator. We recorded 16 normal hearing participants' electroencephalographic activity while listening to vocal and musical emotional bursts in their original form and in a degraded (CI-simulated) condition. We found prolonged P50 latency and reduced N100-P200 complex amplitude in the CI-simulated condition. This points to a limitation in encoding sound signals processed through CI simulation. When comparing the processing of vocal and musical bursts, we found a delay in latency with the musical bursts compared to the vocal bursts in both conditions (original and CI-simulated). This suggests that despite the cochlear implants' limitations, the auditory cortex can distinguish between vocal and musical stimuli. In addition, it adds to the literature supporting the complexity of musical emotion. Replicating this study with actual CI users might lead to characterizing emotional processing in CI users and could ultimately help develop optimal rehabilitation programs or device processing strategies to improve CI users' quality of life.

Speech Recognition Outcomes After Cochlear Reimplantation Surgery.

This study compares speech recognition outcomes before and after cochlear reimplantation surgery, in relation to clinical factors known before and at time of surgery. Between 2006 and 2015, 2,055 adult cochlear implant surgeries were conducted at this center, of which 87 were reimplantation surgeries (4.2%). Speech recognition scores (SRS) assessed before and after reimplantation were available for 54 adults. Overall, SRS measured after reimplantation were similar to the best SRS obtained by the patient and greater than the last SRS measured before surgery. Additional complications were noted in the clinical files of all patients for which reimplantation was considered unsuccessful (16%).

Morphological correlates of hearing loss after cochlear implantation and electro-acoustic stimulation in a hearing-impaired Guinea pig model.

Hybrid or electro-acoustic stimulation (EAS) cochlear implants (CIs) are designed to provide high-frequency electric hearing together with residual low-frequency acoustic hearing. However, 30-50% of EAS CI recipients lose residual hearing after implantation. The objective of this study was to determine the mechanisms of EAS-induced hearing loss in an animal model with high-frequency hearing loss. Guinea pigs were exposed to 24 h of noise (12-24 kHz at 116 dB) to induce a high-frequency hearing loss. After recovery, two groups of animals were implanted (n = 6 per group), with one group receiving chronic acoustic and electric stimulation for 10 weeks, and the other group receiving no stimulation during this time frame. A third group (n = 6) was not implanted, but received chronic acoustic stimulation. Auditory brainstem responses were recorded biweekly to monitor changes in hearing. The organ of Corti was immunolabeled with phalloidin, anti-CtBP2, and anti-GluR2 to quantify hair cells, ribbons and post-synaptic receptors. The lateral wall was immunolabeled with phalloidin and lectin to quantify stria vascularis capillary diameters. Bimodal or trimodal diameter distributions were observed; the number and location of peaks were objectively determined using the Aikake Information Criterion and Expectation Maximization algorithm. Noise exposure led to immediate hearing loss at 16-32 kHz for all groups. Cochlear implantation led to additional hearing loss at 4-8 kHz; this hearing loss was negatively and positively correlated with minimum and maximum peaks of the bimodal or trimodal distributions of stria vascularis capillary diameters, respectively. After chronic stimulation, no significant group changes in thresholds were seen; however, elevated thresholds at 1 kHz in implanted, stimulated animals were significantly correlated with decreased presynaptic ribbon and postsynaptic receptor counts. Inner and outer hair cell counts did not differ between groups and were not correlated with threshold shifts at any frequency. As in the previous study in a normal-hearing model, stria vascularis capillary changes were associated with immediate hearing loss after implantation, while little to no hair cell loss was observed even in cochlear regions with threshold shifts as large as 40-50 dB. These findings again support a role of lateral wall blood flow changes, rather than hair cell loss, in hearing loss after surgical trauma, and implicate the endocochlear potential as a factor in implantation-induced hearing loss. Further, the analysis of the hair cell ribbons and post-synaptic receptors suggest that delayed hearing loss may be linked to synapse or peripheral nerve loss due to stimulation excitotoxicity or inflammation. Further research is needed to separate these potential mechanisms of delayed hearing loss.

Endolymphatic hydrops is prevalent in the first weeks following cochlear implantation.

AIM: To explore morphological or electrophysiological evidence for the presence of endolymphatic hydrops (EH) in guinea pig cochleae in the first 3 months after cochlear implantation. METHODS: Dummy silastic electrodes were implanted atraumatically into the basal turn of scala tympani via a cochleostomy. Round window electrocochleography (ECochG) was undertaken prior to and after implantation. Animals survived for 1, 7, 28 or 72 days prior to a terminal experiment, when ECochG was repeated. The cochleae were imaged using micro-CT after post-fixing with osmium tetroxide to reveal the inner ear soft tissue structure. EH was assessed by visual inspection at a series of frequency specific places along the length of the cochlea, and the extent to which Reissner's membrane departed from its neutral position was quantified. Tissue response volumes were calculated. Using ECochG, the ratio of the summating potential to the action potential (SP/AP ratio) was calculated in response to frequencies between 2 and 32 kHz. RESULTS: There was minimal evidence of electrode trauma from cochlear implantation on micro-CT imaging. Tissue response volumes did not change over time. EH was most prevalent 7 days after surgery in implanted ears, as determined by visual inspection. Scala media areas were increased, as expected in cases of EH, over the first month after cochlear implantation. SP/AP ratios decreased immediately after surgery, but were elevated 1 and 7 days after implantation. CONCLUSIONS: EH is prevalent in the first weeks after implant surgery, even in the absence of significant electrode insertion trauma.

Correlation of Electrophysiological Properties and Hearing Preservation in Cochlear Implant Patients.

OBJECTIVE: To monitor changes in cochlear function during cochlear implantation using electrocochleography (ECoG) and to correlate changes to postoperative hearing preservation. METHODS: ECoG responses to acoustic stimuli of 250, 500, and 1000 Hz were recorded during cochlear implantation. The recording electrode was placed on the promontory and stabilized to fix the position during cochlear implantation. Baseline recordings were obtained after completion of the posterior tympanotomy. Changes of the ongoing ECoG response at suprathreshold intensities were analyzed after full insertion of the cochlear implant electrode array. Audiometric tests were conducted before and 4 weeks after surgery and correlated with electrophysiological findings. RESULTS: Ninety-five percent (18/19) of cochlear implant subjects had measurable ECoG responses. Under unchanged conditions, recordings showed a high repeatability without significant differences between 2 recordings (p ≤ 0.01). Ninety-four percent (17/18) of subjects showed no relevant changes in ECoG recordings after insertion of the cochlear implant electrode array. One subject showed decreases in responses at all frequencies indicative of cochlear trauma. This was associated with a complete hearing loss 4 weeks after surgery compared with mean presurgical low-frequency hearing of 78 dB HL. CONCLUSION: Extracochlear ECoG is a reliable tool to assess cochlear function during cochlear implantation. Moderate threshold shifts could be caused by postoperative mechanisms or minor cochlear trauma. Detectable changes in extracochlear ECoG recordings, indicating gross cochlear trauma, are probably predictive of complete loss of residual acoustic hearing.

Simultaneous Assessment of Speech Identification and Spatial Discrimination: A Potential Testing Approach for Bilateral Cochlear Implant Users?

With increasing numbers of children and adults receiving bilateral cochlear implants, there is an urgent need for assessment tools that enable testing of binaural hearing abilities. Current test batteries are either limited in scope or are of an impractical duration for routine testing. Here, we report a behavioral test that enables combined testing of speech identification and spatial discrimination in noise. In this task, multitalker babble was presented from all speakers, and pairs of speech tokens were sequentially presented from two adjacent speakers. Listeners were required to identify both words from a closed set of four possibilities and to determine whether the second token was presented to the left or right of the first. In Experiment 1, normal-hearing adult listeners were tested at 15° intervals throughout the frontal hemifield. Listeners showed highest spatial discrimination performance in and around the frontal midline, with a decline at more eccentric locations. In contrast, speech identification abilities were least accurate near the midline and showed an improvement in performance at more lateral locations. In Experiment 2, normal-hearing listeners were assessed using a restricted range of speaker locations designed to match those found in clinical testing environments. Here, speakers were separated by 15° around the midline and 30° at more lateral locations. This resulted in a similar pattern of behavioral results as in Experiment 1. We conclude, this test offers the potential to assess both spatial discrimination and the ability to use spatial information for unmasking in clinical populations.

Non-penetrating round window electrode stimulation for tinnitus therapy followed by cochlear implantation.

One main theory behind the origin of tinnitus is based on the idea that alterations of the spontaneous electrical activity within the auditory system lead to abnormal firing patterns in the affected nervous structures [1]. A possible therapeutic option is the use of electrical stimulation of the auditory nerve for the recovery or at least limitation of the abnormal firing pattern to a level that can be easily tolerated by the patient. The Tinnelec Implant consists of a single non-penetrating stimulation electrode connected to a Neurelec cochlear implant system. As a first feasibility study, before starting implantations in hearing patients, we thought to assess the potential of the Tinnelec stimulation to treat tinnitus in unilateral deaf patients, analysing hereby its effectivity and risks. Three patients suffering from unilateral tinnitus resistant to pharmacological treatment and ipsilateral severe to profound sensorineural hearing loss/deafness were implanted with a Tinnelec system between September 2007 and July 2008, at the ENT Department of Hannover Medical School. The stimulation strategy was chosen to induce alleviation of the tinnitus through suppression, masking and/or habituation and the response of each patient on the treatment was monitored using a visual analogue scale (VAS) on loudness and annoyance of tinnitus, mood of the patient, as well as the tinnitus handicap inventory (THI). All patients had a benefit from the electrical stimulation for their tinnitus (THI-score improvement of 20-70), however, not all participants profited from the Tinnelec system in same way and degree. In one patient, despite good results, the device had to be replaced with a conventional cochlear implant because of Tinnelec-independent increase in hearing loss on the contralateral ear. Additionally, due to the extension of cochlear implant indications, the devices of the other two patients have been meanwhile replaced with a conventional cochlear implant to benefit additionally from hearing improvement. As demonstrated in the present study, sensorineural tinnitus in humans may be suppressed/masked/habituated by electrical stimulation. The main advantage of the Tinnelec implant would be the option to treat patients with normal and usable hearing, stimulating the affected ear with the cochlear non-penetrating stimulation electrode of the device, and extend the treatment in cases of progressive hearing loss by explanation and reimplantation with a penetrating electrode addressing tinnitus as well as the hearing impairment. The present study is the first report on a long-term follow-up on tinnitus patients implanted with Tinnelec. Further clinical studies to implant tinnitus patients with residual or normal hearing on the affected ear are on the way.

Safety, efficacy, and hearing preservation using an integrated electro-acoustic stimulation hearing system.

OBJECTIVE: To determine the safety, efficacy, and potential for hearing preservation of an electroacoustic hearing system in patients with severe high-frequency and moderate low-frequency hearing loss. PATIENTS: Five patients were included in this study with steeply down-sloping sensorineural hearing loss. All patients had a history of hearing aid use and similar hearing in the contralateral ear. Ages ranged from 48 to 69 years. INTERVENTION: All participants were implanted with an electro-acoustic stimulation (EAS) device using a hearing preservation technique. This device integrates electric and acoustic stimulation into a single processor for simultaneous ipsilateral bimodal stimulation. MAIN OUTCOME MEASURE(S): Pure-tone audiograms (PTA) and speech reception thresholds (SRTs) during preoperative evaluation; initial cochlear implant (CI) stimulation; initial EAS stimulation; and at 3, 6, and 12 months poststimulation. Consonant-Nucleus-Consonant (CNC) monosyllables preoperatively and at 3, 6, and 12 months poststimulation. RESULTS: All participants showed preserved hearing in the surgical ear after implantation as measured by PTA and SRT. Significant improvement in speech recognition testing over hearing aid was observed at 3 months with EAS versus 6 months with CI-only stimulation. Facial stimulation occurred in 1 patient and resolved after reprogramming. CONCLUSION: There were no significant complications in this cohort of patients. Adequate hearing preservation was achieved. EAS and CI aided conditions both showed significant improvement over hearing aid with EAS condition achieving significance sooner.

Relations between cochlear histopathology and hearing loss in experimental cochlear implantation.

This study reviews the cochlear histology from four hearing preservation cochlear implantation experiments conducted on 73 guinea pigs from our institution, and relates histopathological findings to residual hearing. All guinea pigs had normal hearing prior to surgery and underwent cochlear implantation via a cochleostomy with a silastic-platinum dummy electrode. Pure tone auditory brainstem response (ABR) thresholds from 2 to 32 kHz were recorded prior to surgery, and at one and four weeks postoperatively. The cochleae were then fixed in paraformaldehyde, decalcified, paraffin embedded, and mid-modiolar sections were prepared. The treatment groups were as follows: 1) Systemic dexamethasone, 0.2 mg/kg administered 1 h before implantation, 2) Local dexamethasone, 2% applied topically to the round window for 30 min prior to cochlear implantation, 3) Local n-acetyl cysteine, 200 µg applied topically to the round window for 30 min prior to implantation, 4) inoculation to keyhole-limpet hemocyanin (KLH) prior to implantation, and 5) untreated controls. There was a significant correlation between the extent of the tissue reaction in the cochlea and the presence of foreign body giant cells (FBGCs), new bone formation and injury to the osseous spiral lamina (OSL). The extent of the tissue response, as a percentage of the area of the scala tympani, limited the best hearing that was observed four weeks after cochlear implantation. Poorer hearing at four weeks correlated with a more extensive tissue response, lower outer hair cell (OHC) counts and OSL injury in the basal turn. Progressive hearing loss was also correlated with the extent of tissue response. Hearing at 2 kHz, which corresponds to the region of the second cochlear turn, did not correspond with loco-regional inner hair cell (IHC), OHC or SGC counts. We conclude that cochlear injury is associated with poorer hearing early after implantation. The tissue response is related to indices of cochlear inflammation and injury. An extensive tissue response limits hearing at four weeks, and correlates with progressive hearing loss. These latter effects may be due to inflammation, but would also be consistent with interference of cochlear mechanics.

Reliability measure of a clinical test: Appreciation of Music in Cochlear Implantees (AMICI).

PURPOSE: The goals of this study were (1) to investigate the reliability of a clinical music perception test, Appreciation of Music in Cochlear Implantees (AMICI), and (2) examine associations between the perception of music and speech. AMICI was developed as a clinical instrument for assessing music perception in persons with cochlear implants (CIs). The test consists of four subtests: (1) music versus environmental noise discrimination, (2) musical instrument identification (closed-set), (3) musical style identification (closed-set), and (4) identification of musical pieces (open-set). To be clinically useful, it is crucial for AMICI to demonstrate high test-retest reliability, so that CI users can be assessed and retested after changes in maps or programming strategies. RESEARCH DESIGN: Thirteen CI subjects were tested with AMICI for the initial visit and retested again 10-14 days later. Two speech perception tests (consonant-nucleus-consonant [CNC] and Bamford-Kowal-Bench Speech-in-Noise [BKB-SIN]) were also administered. DATA ANALYSIS: Test-retest reliability and equivalence of the test's three forms were analyzed using paired t-tests and correlation coefficients, respectively. Correlation analysis was also conducted between results from the music and speech perception tests. RESULTS: Results showed no significant difference between test and retest (p > 0.05) with adequate power (0.9) as well as high correlations between the three forms (Forms A and B, r = 0.91; Forms A and C, r = 0.91; Forms B and C, r = 0.95). Correlation analysis showed high correlation between AMICI and BKB-SIN (r = -0.71), and moderate correlation between AMICI and CNC (r = 0.4). CONCLUSIONS: The study showed AMICI is highly reliable for assessing musical perception in CI users.

Stimulation rate reduction and auditory development in poorly performing cochlear implant users with auditory neuropathy.

OBJECTIVE: Patients with auditory neuropathy spectrum disorder (ANSD) exhibit altered neural synchrony in response to auditory stimuli. It has been hypothesized that a slower rate of electrical stimulation in programming strategies for cochlear implant (CI) users with ANSD may enhance development of neural synchrony and speech perception abilities. STUDY DESIGN: Retrospective case series. SETTING: Tertiary otologic practice. PATIENTS: Twenty-two patients with ANSD underwent CI. Patients with complete postoperative audiometric data and at least 2 years of follow-up were included in further analysis. INTERVENTION: Thirteen patients patients met inclusion criteria. Five "poorly performing" CI recipients with ANSD who had not developed closed-set speech perception abilities despite at least 2 years of implant use underwent implant programming to lower the neural stimulation rate. MAIN OUTCOME MEASURES: Speech perception abilities over time using parent questionnaire, closed-set testing, and open-set measures. RESULTS: A high incidence of comorbid conditions was present in the poor performers, including cognitive delay (n = 2), motor delay (n = 3), and autism spectrum disorder (n = 1). The median time to rate slowing in 5 poor performers was 29 months after implant activation. Three of 5 patients achieved closed-set speech perception scores higher than 60% after 6 to 16 months of implant use at the slower rates. At last follow-up (median, 42 mo), no poor performer had yet achieved open-set speech perception abilities. Of all CI recipients with ANSD included in analysis, open-set speech perception abilities developed in 46% (6/13). CONCLUSION: In CI recipients with ANSD who demonstrate limited auditory skills development despite prolonged implant use, lowering the stimulation rate may facilitate acquisition of closed-set speech perception abilities. Further efforts on the study of programming parameters in ANSD patients with CIs are necessary to maximize auditory development in this patient population.

Cochlear implants: clinical and societal outcomes.

Over the past 30 years, hearing care clinicians have increasingly relied on cochlear implants to restore auditory sensitivity in selected patients with advanced sensorineural hearing loss. This article examines the impact of intervention with cochlear implantation in children and adults. The authors report a range of clinic-based results and patient-based outcomes reflected in the reported literature on cochlear implants. The authors describe the basic assessment of the physiologic response to auditory nerve stimulation; measures of receptive and productive benefit; and surveys of life effects as reflected measures of quality of life, educational attainment, and economic impact.