Faculty Bibliography

OBJECTIVE:To describe outcomes with cochlear implantation (CI) for rehabilitation of hearing loss in patients with sporadic vestibular schwannomas (VS) and other retrocochlear pathologies. STUDY DESIGN/METHODS:Retrospective review. SETTING/METHODS:Tertiary-care center. PATIENTS/METHODS:Twenty three cases in 19 patients (53% men, mean age 55.8 yr) with non-neurofibromatosis type 2 related retrocochlear pathology. INTERVENTIONS/METHODS:Unilateral or bilateral CI. MAIN OUTCOME MEASURES/METHODS:Word recognition score, device usage. RESULTS:Etiology of deafness included sporadic VS (n = 9, 39%), radiation after head and neck or central nervous system (CNS) malignancy (n = 8, 35%), superficial siderosis (n = 3, 13%), neurosarcoidosis (n = 2, 9%), and pontine stroke (n = 1, 4%). Mean follow-up duration was 2.3 years (standard deviation [SD] 3.0; range, 0.2-9.4). Auditory perception was achieved in 20 out of 22 patients (91%) who have been activated. Mean WRS in patients with sporadic VS was 18% (SD 20; range, 0-44). Mean WRS in patients with non-VS retrocochlear pathology was 55% (SD 30; range, 0-94). Data logs showed 7.0 h/d of average use (SD 4.3; range, 0-13). CONCLUSIONS:Appropriately selected patients with retrocochlear pathology may benefit from CI so long as the patient has a cochlear fluid signal and an intact cochlear nerve. Patients with sporadic VS patients and normal contralateral hearing exhibited guarded outcomes with CI, whereas most patients with non-VS retrocochlear pathologies demonstrated open-set speech understanding scores comparable to or slightly worse than conventional CI candidates. Since variable performance benefit is observed with CI in patients with retrocochlear pathology, counseling is imperative to align patient expectations with realistic outcomes.

OBJECTIVE:To describe our experience with adults undergoing cochlear implantation (CI) for treatment of single-sided deafness (SSD). STUDY DESIGN/METHODS:Retrospective case review. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:Fifty-three adults with SSD. INTERVENTIONS/METHODS:Unilateral CI. MAIN OUTCOME MEASURES/METHODS:Speech perception testing in quiet and noise, tinnitus suppression, and device usage from datalogs. RESULTS:The mean age at CI was 53.2 years (SD 11.9). The mean duration of deafness was 4.0 years (SD 7.8). The most common etiology was idiopathic sudden SNHL (50%). Word recognition improved from 8.7% (SD 15) preoperatively to 61.8% (SD 20) at a mean follow-up of 3.3 years (SD 1.8) (p < 0.0001). Adaptive speech recognition testing in the "binaural with CI" condition (speech directed toward the front and noise toward the normal hearing ear) revealed a significant improvement by 2.6-dB SNR compared to the preoperative unaided condition (p = 0.0002) and by 3.6-dB SNR compared to when a device to route sound to the contralateral side was used (p < 0.0001). Tinnitus suppression was reported to be complete in 23 patients (43%) and improved in 20 patients (38%) while the device was on. The addition of the CI did not lead to a decrement in hearing performance in any spatial configuration. Device usage averaged 8.7 (SD 3.7) hours/day. CONCLUSIONS:Cochlear implantation in adult SSD patients can suppress tinnitus and achieve speech perception outcomes comparable with CI in conventional candidates. Modest improvements in spatial hearing were also observed and primarily attributable to the head shadow effect. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes.

As cochlear implant (CI) candidacy has expanded, commercial payers in the United States have varied in their adoption of new indications, potentially confusing providers' knowledge about appropriate patients for referral. We reviewed how third-party payers classify the medical necessity of cochlear implants for a variety of indications across the lifespan. We compared policies of the six largest commercial payers in our region, focusing on clinical scenarios for which many centers experience difficulty obtaining pre-authorization. These include: (1) CI in children under 12 months, (2) audiometric and speech perception criteria in children, (3) sequential bilateral CI, (4) electro-acoustic stimulation, (5) impending cochlear ossification, and (6) single-sided deafness (SSD). Of the more notable findings for the clinical scenarios half of commercial payers have a pediatric age requirement of greater than 12 months. Generally, audiologic and speech perception criteria are more stringent for children than adults across all policies. SSD is considered investigational by most policies. Third-party payers employ variable criteria regarding the medical necessity of CI, many of which are not contemporaneous with clinical knowledge and best practices. This may impact referral patterns among audiologists. More methodologically rigorous clinical trials may help shift such restrictive policies to benefit a greater number of patients.

OBJECTIVE:To describe our experience with children undergoing unilateral cochlear implantation (CI) for treatment of single-sided deafness (SSD). STUDY DESIGN/METHODS:Retrospective case series. METHODS:A retrospective case review from a tertiary referral center involving 14 pediatric patients (<18 years) with SSD who underwent unilateral CI. Speech perception testing in quiet and noise in the CI-only and bimodal conditions with at least 1 year of device use and device usage from data logs represent the main outcome measures. RESULTS:The mean age at CI was 5.0 years (median 4.4, range 1.0-11.8 years). The mean duration of deafness was 3.0 years (median 2.4, range 0.6-7.0 years). Mean follow-up was 3.4 years. Speech perception testing with a minimum of 1 year post-CI was available in eight patients. The mean word recognition scores (WRS) in the CI-only condition was 56%; a significant improvement from baseline. Testing in background noise with spatially separated speech and noise revealed that patients scored as well or better with the CI-on versus CI-off in all conditions and in no cases was interference from the CI noted. Data logs were reviewed for device usage which revealed an average use of 6.5 hr/d. CONCLUSION/CONCLUSIONS:Cochlear implantation is a viable treatment option for pediatric SSD in this self-selected cohort. Open-set speech and improvement in background noise can be achieved. Careful patient selection and thorough counseling on expectations is paramount to achieving successful outcomes. LEVEL OF EVIDENCE/METHODS:IV Laryngoscope, 2020.

PURPOSE/OBJECTIVE:Some cochlear implant (CI) patients lose their residual hearing during surgery. Two factors that might play a role in residual hearing loss are the change in intracochlear hydraulic pressure and force on the cochlear wall during electrode insertion. The aim of this study is to investigate whether a difference in peak hydraulic pressure and peak force on the cochlear wall exists during a CI electrode insertion with different insertion techniques. MATERIALS AND METHODS/METHODS:Twenty fresh frozen temporal bones were used. Hydraulic pressure and force on the cochlear wall were recorded during straight electrode insertions with 1) slow versus fast insertion speed, 2) manual versus automatic insertion method and 3) round window approach (RWA) versus extended RWA (ERWA). RESULTS:When inserting with a slow compared to a fast insertion speed, the peak hydraulic pressure is 239% (95% CI: 130-399%) higher with a RWA and 58% (95% CI: 6-137%) higher with an ERWA. However, the peak force on the cochlear wall is a factor 29% less (95% CI: 13-43%) with a slow insertion speed. No effect was found of opening and insertion method. CONCLUSIONS:As contradictory findings were found for hydraulic pressure and force on the cochlear wall on insertion speed, it remains unclear which insertion speed (slow versus fast) is less traumatic to inner ear structure.

Two notes sounded sequentially elicit melodic intervals and contours that form the basis of melody. Many previous studies have characterized pitch perception in cochlear implant (CI) users to be poor which may be due to the limited spectro-temporal resolution and/or spectral warping with electric hearing compared to acoustic hearing (AH). Poor pitch perception in CIs has been shown to distort melodic interval perception. To characterize this interval distortion, we recruited CI users with either normal (single sided deafness, SSD) or limited (bimodal) AH in the non-implanted ear. The contralateral AH allowed for a stable reference with which to compare melodic interval perception in the CI ear, within the same listener. Melodic interval perception was compared across acoustic and electric hearing in 9 CI listeners (4 bimodal and 5 SSD). Participants were asked to rank the size of a probe interval presented to the CI ear to a reference interval presented to the contralateral AH ear using a method of constant stimuli. Ipsilateral interval ranking was also measured within the AH ear to ensure that listeners understood the task and that interval ranking was stable and accurate within AH. Stimuli were delivered to the AH ear via headphones and to the CI ear via direct audio input (DAI) to participants' clinical processors. During testing, a reference and probe interval was presented and participants indicated which was larger. Ten comparisons for each reference-probe combination were presented. Psychometric functions were fit to the data to determine the probe interval size that matched the reference interval. Across all AH reference intervals, the mean matched CI interval was 1.74 times larger than the AH reference. However, there was great inter-subject variability. For some participants, CI interval distortion varied across different reference AH intervals; for others, CI interval distortion was constant. Within the AH ear, ipsilateral interval ranking was accurate, ensuring that participants understood the task. No significant differences in the patterns of results were observed between bimodal and SSD CI users. The present data show that much larger intervals were needed with the CI to match contralateral AH reference intervals. As such, input melodic patterns are likely to be perceived as frequency compressed and/or warped with electric hearing, with less variation among notes in the pattern. The high inter-subject variability in CI interval distortion suggests that CI signal processing should be optimized for individual CI users.

OBJECTIVES:There are many potential advantages to combined electric and acoustic stimulation (EAS) with a cochlear implant (CI), including benefits for hearing in noise, localization, frequency selectivity, and music enjoyment. However, performance on these outcome measures is variable, and the residual acoustic hearing may not be beneficial for all patients. As such, we propose a measure of spectral resolution that might be more predictive of the usefulness of the residual hearing than the audiogram alone. In the following experiments, we measured performance on spectral resolution and speech perception tasks in individuals with normal hearing (NH) using low-pass filters to simulate steeply sloping audiograms of typical EAS candidates and compared it with performance on these tasks for individuals with sensorineural hearing loss with similar audiometric configurations. Because listeners with NH had similar levels of audibility and bandwidth to listeners with hearing loss, differences between the groups could be attributed to distortions due to hearing loss. DESIGN:Listeners with NH (n = 12) and those with hearing loss (n = 23) with steeply sloping audiograms participated in this study. The group with hearing loss consisted of 7 EAS users, 14 hearing aid users, and 3 who did not use amplification in the test ear. Spectral resolution was measured with the spectral-temporal modulated ripple test (SMRT), and speech perception was measured with AzBio sentences in quiet and noise. Listeners with NH listened to stimuli through low-pass filters and at two levels (40 and 60 dBA) to simulate low and high audibility. Listeners with hearing loss listened to SMRT stimuli unaided at their most comfortable listening level and speech stimuli at 60 dBA. RESULTS:Results suggest that performance with SMRT is significantly worse for listeners with hearing loss than for listeners with NH and is not related to audibility. Performance on the speech perception task declined with decreasing frequency information for both listeners with NH and hearing loss. Significant correlations were observed between speech perception, SMRT scores, and mid-frequency audiometric thresholds for listeners with hearing loss. CONCLUSIONS:NH simulations describe a "best case scenario" for hearing loss where audibility is the only deficit. For listeners with hearing loss, the likely broadening of auditory filters, loss of cochlear nonlinearities, and possible cochlear dead regions may have contributed to distorted spectral resolution and thus deviations from the NH simulations. Measures of spectral resolution may capture an aspect of hearing loss not evident from the audiogram and be a useful tool for assessing the contributions of residual hearing post-cochlear implantation.

OBJECTIVE:To determine factors associated with infection, management, and resultant outcomes following pediatric cochlear implantation. STUDY DESIGN/METHODS:Retrospective cohort study with nested case series. SETTING/METHODS:Tertiary academic medical center. PATIENTS/METHODS:Children who underwent either unilateral or bilateral cochlear implantation between June 2011 and September 2016 and were under the age of 18 at the time of surgery. INTERVENTION(S)/METHODS:Subjects were compared based on age, cochlea malformation, revision surgery, operative time, device manufacturer, and antibiotic use. Infections were compared based on location, time, bacteria, management, and resolution. MAIN OUTCOME MEASURE(S)/METHODS:Rate of infection, rate of device explantation. RESULTS:There were 16 infections among 246 surgeries, an infection rate of 6.5%. There was a significant age difference between infected and noninfected patients overall (n = 246, 1.4 versus 4.3 years, p = 0.005), but not within the cohort of patients five or younger (n = 172, 1.4 versus 1.8 years, p = 0.363). The most common infectious complication was skin infection, followed by device infection. No cases of meningitis were seen. The most common organism was S Aureus. The implant was salvaged in 9 of 16 patients (56.3%), with higher rates in patients treated with IV versus oral antibiotics (70 versus 40%). CONCLUSIONS:Postoperative infection is positively associated with younger age overall, but not in patients below the age of 5. With modern devices and surgical practices, risk of meningitis-though a concern-may be lower than cited in the literature. Prompt and aggressive therapy with IV antibiotics and operative intervention can allow for high rates of device salvage.

BACKGROUND:Prior studies have shown an advantage for electro-acoustic stimulation (EAS) in cochlear implant (CI) patients with residual hearing, but the degree of benefit can vary. The objective was to explore which factors relate to performance with and acceptance of EAS for CI users with conventional-length electrodes. METHODS:A retrospective chart review was conducted for adults with an average threshold of 75 dB hearing loss or better across 250 and 500 Hz preoperatively (n = 83). All patients underwent cochlear implantation with a conventional-length electrode. Low-frequency audiometric thresholds were measured at initial activation as well as 3 and 12 months postoperatively to determine who met the criteria for EAS. Speech perception for CNC words and AzBio sentences in quiet and +10 dB SNR noise was evaluated 3 and 12 months after activation. RESULTS:Speech perception in quiet and noise was similar regardless of whether or not the patient was eligible for EAS. Less than half of the patients who met the EAS criteria chose to use it, citing reasons such as physical discomfort or lack of perceived benefit. EAS users performed better on CNC words but not sentence recognition than EAS nonusers. CONCLUSIONS:EAS use is dependent on audiologic and nonaudiologic issues. Hearing preservation is possible with conventional electrodes, but hearing preservation alone does not guarantee superior speech perception.