Faculty Bibliography

OBJECTIVES/OBJECTIVE:A method for stimulating the cochlear apex using perimodiolar electrode arrays is described. This method involves implanting an electrode (ECE1) into the helioctrema in addition to standard cochlear implant placement. One objective is to verify a suitable approach for implanting ECE1 in the helicotrema. Another is to determine how placement of ECE1 reshapes electric fields. DESIGN/METHODS:Two cadaveric half-heads were implanted, and electric voltage tomography was measured with ECE1 placed in many positions. RESULTS:An approach for placing ECE1 was identified. Changes in electric fields were only observed when ECE1 was placed into the fluid in the helicotrema. When inside the helicotrema, electric voltage tomography modeling suggests an increased current flow toward the apex. CONCLUSIONS:Placement of ECE1 into the cochlear apex is clinically feasible and has the potential to reshape electric fields to stimulate regions of the cochlea more apical than those represented by the electrode array.

IMPORTANCE/UNASSIGNED:Management of sporadic vestibular schwannoma with radiosurgery is becoming increasingly common globally; however, limited data currently characterize patient outcomes in the setting of microsurgical salvage for radiosurgical failure. OBJECTIVE/UNASSIGNED:To describe the clinical outcomes of salvage microsurgery following failed primary stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) among patients with sporadic vestibular schwannoma. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This was a cohort study of adults (≥18 years old) with sporadic vestibular schwannoma who underwent salvage microsurgery following failed primary SRS/FSRT in 7 vestibular schwannoma treatment centers across the US and Norway. Data collection was performed between July 2022 and January 2023, with data analysis performed between January and July 2023. EXPOSURE/UNASSIGNED:Salvage microsurgical tumor resection. MAIN OUTCOMES AND MEASURES/UNASSIGNED:Composite outcome of undergoing less than gross total resection (GTR) or experiencing long-term facial paresis. RESULTS/UNASSIGNED:Among 126 patients, the median (IQR) age at time of salvage microsurgery was 62 (53-70) years, 69 (55%) were female, and 113 of 117 (97%) had tumors that extended into the cerebellopontine angle at time of salvage. Of 125 patients, 96 (76%) underwent primary gamma knife SRS, while 24 (19%) underwent linear accelerator-based SRS; the remaining patients underwent FSRT using other modalities. Postoperative cerebrospinal fluid leak was seen in 15 of 126 patients (12%), hydrocephalus in 8 (6%), symptomatic stroke in 7 (6%), and meningitis in 2 (2%). Each 1-mm increase in cerebellopontine angle tumor size was associated with a 13% increased likelihood of foregoing GTR (64 of 102 patients [63%]) or long-term postoperative House-Brackmann grade higher than I (48 of 102 patients [47%]) (odds ratio, 1.13; 95% CI, 1.04-1.23). Following salvage microsurgery, tumor growth-free survival rates at 1, 3, and 5 years were 97% (95% CI, 94%-100%), 93% (95% CI, 87%-99%), and 91% (95% CI, 84%-98%), respectively. CONCLUSIONS/UNASSIGNED:In this cohort study, more than half of patients who received salvage microsurgery following primary SRS/FSRT underwent less than GTR or experienced some degree of facial paresis long term. These data suggest that the cumulative risk of developing facial paresis following primary SRS/FSRT by the end of the patient's journey with treatment approximates 2.5% to 7.5% when using published primary SRS/FSRT long-term tumor control rates.

OBJECTIVE:To assess the safety of cochlear implants (CIs) in children under 9 months of age to better understand expected postoperative complication rates, and to provide a preliminary look at efficacy. STUDY DESIGN/METHODS:Single-center retrospective review. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:Children 5 to 8 months of age who received a CI between 2011 and 2021. INTERVENTIONS/METHODS:Therapeutic-CI. MAIN OUTCOME MEASURES/METHODS:The primary outcome was 6-month postoperative complication rate. Secondary outcomes included length of stay, device explantation/reimplantation, rehabilitation supports, and hearing and language outcomes. Complications of children implanted under than 9 months of age was compared with a cohort of children implanted 9 to 18 months of age between the years 2011 and 2016 using a chi-squared test (p < 0.05). RESULTS:One hundred six children under 9 months of age were implanted (204 CIs) at a mean age of 6.6 months (range: 5-8). Postoperative complications occurred in 28 patients (26%) and were often minor. There were no mortalities. There was no statistically significant difference in complications, including reimplantation rates, between patients implanted under 9 months of age and those implanted 9 to 18 months of age. Speech discrimination outcomes were excellent, and mean spoken language outcomes were near normative for typically developing children. CONCLUSIONS:Cochlear implantation can be a safe and effective treatment option for children 5 to 8 months of age. Early hearing screening and referral for infants to receive appropriate intervention will continue to play a critical role in optimizing speech and language outcomes.

OBJECTIVES/OBJECTIVE:Single-sided deafness (SSD) can have consequences for a child's language, educational, and social development. A cochlear implant (CI) is the only device which can restore true binaural hearing, yet they are only approved for children with (SSD) over the age of five in the United States. Reports on speech perception outcomes for children implanted at a younger age are limited. The present study aims to examine the effects of age at implantation, duration of deafness, hearing loss etiology, and presence of additional disabilities on device usage and speech perception outcomes. METHODS:A retrospective chart review was used to examine demographics and speech perception outcomes for 18 children implanted at age five or younger. RESULTS:Speech perception results were highly variable, with some children deriving significant benefit and others demonstrating no sound awareness through the implant alone. Age at implantation and duration of deafness did not have a clear impact on outcomes. Device usage was low in many children, often those with anatomical abnormalities such as a hypoplastic cochlear nerve. There are challenges to assessing speech perception in young children with SSD, leading to a lack of standardized outcome measures. CONCLUSIONS:Early CI for children with SSD may improve speech perception, but benefit is not guaranteed. Candidacy evaluation should consider both medical and audiological factors, in addition to the degree of family support and realistic expectations. Caution is especially warranted in children with significant anatomical anomalies.

OBJECTIVES:Immune-checkpoint inhibitors (ICI) are being utilized with increasing frequency and may be linked to neurologic and audiovestibular toxicities. This report aimed to describe a case of ICI-induced sensorineural hearing loss ultimately requiring bilateral cochlear implantation. METHODS:A 42-year-old female with stage IV metastatic melanoma of the perianal skin was treated with ipilimumab (blocker of cytotoxic T-lymphocyte associated protein 4 [CTLA-4]) and nivolumab (anti-programmed cell death protein 1 [PD1]). After 21 weeks of therapy, she developed sudden vertigo and bilateral hearing loss. A full workup including MRI and lumbar puncture ruled out intracranial parenchymal metastases, leptomeningeal metastases, stroke and intracranial infection. ICI-associated aseptic meningoencephalitis was therefore diagnosed. The patient received systemic steroids as well as intratympanic steroids, which temporarily improved hearing, but eventually developed permanent, bilateral profound sensorineural hearing loss. RESULTS:The patient received bilateral cochlear implants and has demonstrated good performance one year after implantation. DISCUSSION:ICI are being increasingly used to treat a variety of advanced malignancies. This is the first report of bilateral cochlear implants in the context of profound hearing loss after an immunotherapy induced meningoencephalitis. CONCLUSION:ICI carries the risk of potential ototoxicity, including profound SNHL as depicted in our case. Cochlear implantation proved to be beneficial and may be considered in patients with ICI-related hearing loss.

OBJECTIVE:In certain cases, clinicians may consider continued observation of a vestibular schwannoma after initial growth is detected. The aim of the current work was to determine if patients with growing sporadic vestibular schwannomas could be stratified by the likelihood of subsequent growth based on initial growth behavior. STUDY DESIGN/METHODS:Slice-by-slice volumetric tumor measurements from 3,505 serial magnetic resonance imaging studies were analyzed from 952 consecutively treated patients. SETTING/METHODS:Three tertiary-referral centers. PATIENTS/METHODS:Adults with sporadic vestibular schwannoma. INTERVENTIONS/METHODS:Wait-and-scan. MAIN OUTCOME MEASURES/METHODS:Composite end point of subsequent growth- or treatment-free survival rates, where growth is defined as an additional increase of at least 20% in tumor volume from the volume at the time of initial growth. RESULTS:Among 405 patients who elected continued observation despite documented growth, stratification, of volumetric growth rate into less than 25% (reference: n = 107), 25 to less than 50% (hazard ratio [HR], 1.39; p = 0.06; n = 96), 50 to less than 100% (HR, 1.71; p = 0.002; n = 112), and at least 100% (HR, 2.01; p < 0.001; n = 90) change per year predicted the likelihood of future growth or treatment. Subsequent growth- or treatment-free survival rates (95% confidence interval) at year 5 after detection of initial growth were 31% (21-44%) for those with less than 25% growth per year, 18% (10-32%) for those with 25 to less than 50%, 15% (9-26%) for those with 50 to less than 100%, and 6% (2-16%) for those with at least 100%. Neither patient age ( p = 0.15) nor tumor volume at diagnosis ( p = 0.95) significantly differed across stratification groups. CONCLUSIONS:At the time of diagnosis, clinical features cannot consistently predict which tumors will ultimately display aggressive behavior. Stratification by volumetric growth rate at the time of initial growth results in a stepwise progression of increasing likelihood of subsequent growth. When considering continued observation after initial growth detection, almost 95% of patients who have tumors that double in volume between diagnosis and the first detection of growth demonstrate further tumor growth or undergo treatment if observed to 5 years.

BACKGROUND:Cochlear implants (CI) are the treatment of choice for individuals with severe to profound sensorineural hearing loss. A small group of patients, with pathology central to the cochlea, cannot benefit from CI. Examples in children include absence of the cochlear-nerve or cochlear aplasia. In these cases, implantation of an auditory brainstem implant (ABI), directly stimulating the cochlear nucleus, bypassing the inner-ear and auditory-nerve, may be beneficial. OBJECTIVES/OBJECTIVE:Describe a series of children with ABI's treated in Shaare-Zedek, including the first ABI implantation in Israel (2017). METHODS:Of 9 patients with ABI's treated in Shaare Zedek Medical Center ,7 were children implanted between ages 2-8.6 years. Five boys and two girls. Surgeries were conducted in collaboration between neurosurgeons, neurotologists and audiologists (five implanted in Shaare-Zedek and two in New-York University). Follow-up was between 2-6 years. Hearing evaluation was conducted, mainly, with audiograms, categories of auditory performance (CAP), speech perception testing when possible and estimation of device use per day. RESULTS:Six of the seven children, who initially underwent unsuccessful CI, had deficient auditory-nerves. One child had cochlear-aplasia. In 3 children hearing loss was part of the CHARGE syndrome. CAP scores ranged from 0-7 (0,1,3,5,5,7). One child was able to achieve open-set speech perception. CONCLUSIONS:Although functional auditory outcomes for children with ABI are inferior to CI recipients and are highly variable, some children were able to obtain significant benefit. In these children, who are not candidates for CI, the ABI presents the only chance for auditory awareness and may be recommended. DISCUSSION/CONCLUSIONS:John Thomas Roland is a consultant and recipient of research support from Cochlear Americas.

OBJECTIVE:Children with high-frequency severe-to-profound hearing loss and low-frequency residual hearing who do not derive significant benefit from hearing aids are now being considered for cochlear implantation. Previous research shows that hearing preservation is possible and may be desirable for the use of electroacoustic stimulation (EAS) in adults, but this topic remains underexplored in children. The goal of this study was to explore factors relating to hearing preservation, acceptance, and benefits of EAS for children. STUDY DESIGN:Retrospective review. SETTING:Tertiary academic medical center. PATIENTS:Forty children (48 ears) with preoperative low-frequency pure-tone averages of 75 dB HL or less at 250 and 500 Hz (n = 48). INTERVENTION:All patients underwent cochlear implantation with a standard-length electrode. MAIN OUTCOME MEASURE:Low-frequency audiometric thresholds, speech perception, and EAS usage were measured at initial stimulation, and 3 and 12 months postoperatively. Outcomes were compared between children with and without hearing preservation, and between EAS users and nonusers. RESULTS:Hearing was preserved at similar rates as adults but worse for children with an enlarged vestibular aqueduct. Fewer than half of children who qualified to use EAS chose to do so, citing a variety of audiologic and nonaudiologic reasons. No differences were detected in speech perception scores across the groups for words, sentences, or sentences in noise tests. CONCLUSIONS:Neither hearing preservation nor EAS use resulted in superior speech perception in children with preoperative residual hearing; rather, all children performed well after implantation.

OBJECTIVES:To determine rates of hearing preservation and performance in patients who met candidacy for electroacoustic stimulation (EAS) and were implanted with a slim modiolar electrode (CI532 or CI632). DESIGN:Adult patients meeting Food and Drug Administration criteria for electroacoustic stimulation (preoperative low-frequency pure-tone average [LFPTA] less than 60 dB at 125, 250, and 500 Hz and monosyllabic word scores between 10% and 60% in the ear to be implanted), who received a slim modiolar electrode were included. Main outcome measures included rates of hearing preservation, defined as a LFPTA ≤80 dB at 125, 250, and 500 Hz, as well as postoperative low-frequency pure-tone threshold shifts, consonant-Nucleus-Consonant (CNC) word scores and AzBio sentences in noise scores. RESULTS:Forty-six patients met inclusion criteria during a 4-year period. Mean (standard deviation) preoperative LFPTA was 34.5 (13.0) dB, and 71.7% had preserved hearing at initial activation. The mean LFPTA shift in patients who preserved hearing at initial activation was 19.7 (14.6) dB, compared with 62.6 (17.7) dB in patients who did not preserve hearing as per our definition. Perioperative steroid use was not different in patients with and without preserved hearing (X 2 (1, N = 46) = 0.19, p = .67, V = 0.06). One year after surgery, 57% of patients had a decline in LFPTA >80 dB and were no longer considered candidates for EAS, with 34.7% still retaining low-frequency thresholds ≤80 dB. CNC word scores at 1 year were 69.9% and 61.4% among individuals with and without preserved low-frequency hearing respectively, measured in their CI ear alone, in their regular listening condition of EAS or electric only ( t (32) = 1.13, p = 0.27, d = 0.39, 95% CI = -6.51, 22.86). Device use time did not differ between groups. Among adults with preserved residual hearing at 1 year (n = 16), 44% used EAS, although there was no significant difference in performance between EAS users and nonusers with preserved hearing. Loss of residual hearing over time did not result in a decline in speech perception performance. CONCLUSION:The present study demonstrated favorable early rates of hearing preservation with a slim modiolar array. Performance was not significantly different in individuals with and without preserved low-frequency acoustic hearing, independent of EAS use. Compared with reports of short electrode use, the loss of residual hearing in patients implanted with this array did not impact speech perception performance.

OBJECTIVES/OBJECTIVE: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/METHODS: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.