In Vitro Glycosylation of the Membrane Protein γ-Sarcoglycan in Nanodiscs.

Membrane glycoproteins are proteins that reside in the membranes of cells and are post-translationally modified to have sugars attached to their amino acid side chains. Studies of this subset of proteins in their native states are becoming more important since they have been linked to numerous human diseases. However, these proteins are difficult to study due to their hydrophobic nature and their propensity to aggregate. Using membrane mimetics allows us to solubilize these proteins, which, in turn, allows us to perform glycosylation in vitro to study the effects of the modification on protein structure, dynamics, and interactions. Here, the membrane glycoprotein γ-sarcoglycan was incorporated into nanodiscs composed of long-chain lipids and membrane scaffold proteins to perform N-linked glycosylation in which an enzyme attaches a sugar to the asparagine side chain within the glycosylation site. We previously performed glycosylation of membrane proteins in vitro when the protein had been solubilized using different detergents and short-chain lipids. This work demonstrates successful glycosylation of a full-length membrane protein in nanodiscs providing a more biologically relevant sample to study the effects of the modification.

Identification Accuracy of Safety-Relevant Environmental Sounds in Adult Cochlear Implant Users.

OBJECTIVE: Examine cochlear implant (CI) users' ability to identify safety-relevant environmental sounds, imperative for safety, independence, and personal well-being. METHODS: Twenty-one experienced adult CI users completed an Environmental Sound Identification (ESI) test consisting of 42 common environmental sounds, 28 of which were relevant to personal safety, along with 14 control sounds. Prior to sound identification, participants were shown sound names and asked to rate the familiarity and, separately, relevance to safety of each corresponding sound on a 1-5 scale. RESULTS: Overall ESI accuracy was 57% correct for the safety-relevant sounds and 55% correct for control sounds. Participants rated safety-relevant sounds as more important to safety and more familiar than the non-safety sounds. ESI accuracy significantly correlated with familiarity ratings. CONCLUSION: The present findings suggest mediocre ESI accuracy in postlingual adult CI users for safety-relevant and other environmental sounds. Deficits in the identification of these sounds may put CI listeners at increased risk of accidents or injuries and may require a specific rehabilitation program to improve CI outcomes. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2388-2393, 2023.

The Sensory Auricular Branch of the Facial Nerve and its Relationship to Landmarks of the Facial Recess.

OBJECTIVE: Delineate the anatomic relationship of the sensory auricular branch (SAB) of the facial nerve to other structures of the facial recess. METHODS: Ten adult cadaveric temporal bones were randomly selected and dissected under operative microscopy. Linear and angular measurements were obtained for the following parameters: (1) the distance from the tip of the short process of the incus to the point of convergence of the SAB and the main trunk of the facial nerve; (2) the distance from the point of convergence of the SAB and the main trunk of the facial nerve to the chorda tympani (CT) division from the main trunk; (3) the distance from the bifurcation of the CT and facial nerve to the crossover point of the SAB/CT; (4) the angle at which the SAB merges with the main trunk (Y°), and (5) the angle at which the CT divides off the main trunk (X°). RESULTS: The mean distance from the tip of the short process of the incus to the SAB takeoff was 8.7 ± 1.83 mm (range 6-13 mm). The mean distance from the SAB to the CT division from the main trunk was 5.9 ± 2.41 mm (range 3-10 mm). The mean angle at which the SAB merged with the main trunk of the facial nerve was 38.5 ± 12.63° (range 25°-68°). The mean CT-main trunk angle was 16 ± 4.24° (range 8°-21°). The branching point of the SAB from the facial nerve approximately bisected the facial recess. CONCLUSION: Recognizing the SAB and knowing its relationships to surrounding anatomy provides a useful adjunctive landmark for the identification of the main trunk of the facial nerve's mastoid segment. LEVEL OF EVIDENCE: 4.

Contribution of Verbal Learning & Memory and Spectro-Temporal Discrimination to Speech Recognition in Cochlear Implant Users.

OBJECTIVES: Existing cochlear implant (CI) outcomes research demonstrates a high degree of variability in device effectiveness among experienced CI users. Increasing evidence suggests that verbal learning and memory (VL&M) may have an influence on speech recognition with CIs. This study examined the relations in CI users between visual measures of VL&M and speech recognition in a series of models that also incorporated spectro-temporal discrimination. Predictions were that (1) speech recognition would be associated with VL&M abilities and (2) VL&M would contribute to speech recognition outcomes above and beyond spectro-temporal discrimination in multivariable models of speech recognition. METHODS: This cross-sectional study included 30 adult postlingually deaf experienced CI users who completed a nonauditory visual version of the California Verbal Learning Test-Second Edition (v-CVLT-II) to assess VL&M, and the Spectral-Temporally Modulated Ripple Test (SMRT), an auditory measure of spectro-temporal processing. Participants also completed a battery of word and sentence recognition tasks. RESULTS: CI users showed significant correlations between some v-CVLT-II measures (short-delay free- and cued-recall, retroactive interference, and "subjective" organizational recall strategies) and speech recognition measures. Performance on the SMRT was correlated with all speech recognition measures. Hierarchical multivariable linear regression analyses showed that SMRT performance accounted for a significant degree of speech recognition outcome variance. Moreover, for all speech recognition measures, VL&M scores contributed independently in addition to SMRT. CONCLUSION: Measures of spectro-temporal discrimination and VL&M were associated with speech recognition in CI users. After accounting for spectro-temporal discrimination, VL&M contributed independently to performance on measures of speech recognition for words and sentences produced by single and multiple talkers. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:661-669, 2023.

Standardization of Outcome Measures for Intratympanic Steroid Treatment for Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVE: To identify variability in reported hearing outcomes for intratympanic (IT) steroid treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) by comparing outcomes using the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guideline with other published criteria. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary otology practice. PATIENTS: Patients with ISSNHL treated with IT steroid between April 2003 and December 2020. INTERVENTIONS: IT steroid injection and audiometric evaluation. MAIN OUTCOME MEASURES: 1) Rates of full, partial, or no recovery using the AAO-HNS guideline versus other reported criteria, and 2) correlation analyses of demographic and clinical variables with response to IT steroid. RESULTS: Using AAO-HNS reporting criteria, full recovery of the pure-tone average was noted in 25.68% of patients. Applying eight other published outcomes criteria to this patient cohort classified full recovery in 14.87 to 40.54% of patients. Similarly, AAO-HNS criteria classified "no recovery" in 51.35% of our patients, whereas applying the other reported criteria showed an average rate of 62.16% no recovery and as high as 82.43% of patients without recovery. Younger age ( p = 0.003; effect size, 0.924) and IT injection within a week of onset ( p < 0.001; effect size, 1.099) positively correlated with full recovery. There was no impact of prior or concurrent oral steroids, or number of steroid injections on outcome. CONCLUSION: Great variability exists in the literature for assessment of IT steroid outcomes in ISSNHL. Standard reporting of outcomes as per the AAO-HNS SSNHL guideline is recommended to consistently characterize IT steroid efficacy and allow comparison across studies.

Impact of Demographics and Clinical Features on Initial Treatment Pathway for Vestibular Schwannoma.

OBJECTIVE: To identify demographic and clinical features impacting initial treatment pathway for vestibular schwannoma. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care academic medical center. PATIENTS: Patients diagnosed with vestibular schwannoma between 2009 and 2019. INTERVENTIONS: Observation, stereotactic radiosurgery, or microsurgical resection. MAIN OUTCOME MEASURES: χ 2 Test, one-way analysis of variance, and multivariate logistic regression were used to correlate demographic and clinical factors with initial treatment pathway for 197 newly diagnosed vestibular schwannoma patients. RESULTS: Among 197 patients, 93 (47%) were initially treated with observation, 60 (30%) with stereotactic radiation (Gamma Knife) and 44 (22%) with surgical resection. Age univariately had no statistically significant impact on initial pathway, but those undergoing surgery trended toward a younger demographic (49.1 yr [surgery] versus 57.2 yr [observation] versus 59.0 yr [Gamma Knife]). Men were more likely to be initially observed than women ( p = 0.04). Patients initially observed were more likely to have a lower Koos classification ( p < 0.001) and have better tumor-ear hearing ( p = 0.03). Only 34.4% of patients living outside the local geographic region were initially observed compared with 53.0% living locally ( p = 0.055). Surgeon correlated with initial treatment ( p = 0.04) but did not maintain significance when adjusting for hearing level or tumor size. A multiple linear regression model found age, maximum tumor diameter, and Koos class to correlate with initial treatment pathway ( p < 0.0001, r2 = 0.42). CONCLUSION: Initial treatment pathway for newly diagnosed vestibular schwannoma is impacted by demographic factors such as age, sex, and geographic proximity to the medical center. Clinical features including hearing level and tumor size also correlated with initial treatment modality.

Association of Self-Reported Coping Strategies With Speech Recognition Outcomes in Adult Cochlear Implant Users.

OBJECTIVE: To characterize the degree to which individual coping strategies may influence speech perception after cochlear implantation. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: Adult, postlingually deaf cochlear implant recipients. INTERVENTIONS: The Coping Orientation to Problems Experience inventory, a validated, multidimensional self-reported coping scale, was administered preoperatively. MAIN OUTCOME MEASURES: Speech perception was measured using consonant-nucleus-consonant (CNC) phoneme and word scores, AzBio sentence accuracy in quiet and noise, and Hearing in Noise Test sentences in quiet preoperatively and at 1, 3, and 6 months postoperatively. Quality of life was measured with the Hearing Implant Sound Quality Index and the Nijmegen Cochlear Implant Questionnaire. RESULTS: Thirty-six patients were included in this study. Mean age at surgery was 70.7 ± 11.4 years. Acceptance was associated with a decreased AzBio in noise score in the 6 months after CI (regression coefficient b = -0.05; 95% confidence interval [CI], -0.07 to -0.03; p < 0.01). Denial was associated with a decreased AzBio in quiet score (b = -0.05; 95% CI, -0.09 to -0.01; p < 0.05), whereas humor was associated with an increased AzBio in quiet score (b = 0.02; 95% CI, 0.01 to 0.04; p < 0.05). Humor was also associated with an increased Hearing in Noise Test score (b = 0.05; 95% CI, 0.02 to 0.07; p < 0.05). Denial was associated with decreased CNC word (b = -0.04; 95% CI, -0.06 to -0.02; p < 0.01) and phoneme (b = -0.04; 95% CI, -0.07 to -0.02; p < 0.01) scores, whereas substance use was associated with increased CNC word (b = 0.03; 95% CI, 0.01 to 0.05, p < 0.01) and phoneme (b = 0.04; 95% CI, 0.02 to 0.06; p < 0.01) scores. Scores on self-reported quality of life measures were not significantly correlated with coping strategies. CONCLUSION: A variety of adaptive and maladaptive coping strategies are used by postlingually deaf adult cochlear implant users. Denial and acceptance may be more predictive of poor speech performance, whereas humor and substance use may be more predictive of improved speech performance.

Can Electrocochleography Help Preserve Hearing After Cochlear Implantation With Full Electrode Insertion?

OBJECTIVES: To evaluate the utility of intracochlear electrocochleography (ECochG) monitoring during cochlear implant (CI) surgery on postoperative hearing preservation. STUDY DESIGN: Prospective, randomized clinical trial. SETTING: Ten high-volume, tertiary care CI centers. PATIENTS: Adult patients with sensorineural hearing loss meeting the CI criteria who selected an Advanced Bionics CI. METHODS: Patients were randomized to CI surgery either with audible ECochG monitoring available to the surgeon during electrode insertion or without ECochG monitoring. Hearing preservation was determined by comparing preoperative unaided low-frequency (125-, 250-, and 500-Hz) pure-tone average (LF-PTA) to postoperative LF-PTA at CI activation. Pre- and post-CI computed tomography was used to determine electrode scalar location and electrode translocation. RESULTS: Eighty-five adult CI candidates were enrolled. The mean (standard deviation [SD]) unaided preoperative LF-PTA across the sample was 54 (17) dB HL. For the whole sample, hearing preservation was "good" (i.e., LF-PTA change 0-15 dB) in 34.5%, "fair" (i.e., LF-PTA change >15-29 dB) in 22.5%, and "poor" (i.e., LF-PTA change ≥30 dB) in 43%. For patients randomized to ECochG "on," mean (SD) LF-PTA change was 27 (20) dB compared with 27 (23) dB for patients randomized to ECochG "off" ( p = 0.89). Seven percent of patients, all of whom were randomized to ECochG off, showed electrode translocation from the scala tympani into the scala vestibuli. CONCLUSIONS: Although intracochlear ECochG during CI surgery has important prognostic utility, our data did not show significantly better hearing preservation in patients randomized to ECochG "on" compared with ECochG "off."

Relationship Between Intraoperative Electrocochleography and Hearing Preservation.

OBJECTIVES: To compare intraoperative intracochlear electrocochleography (ECochG) with hearing preservation outcomes in cochlear implant (CI) subjects. DESIGN: Intraoperative electrocochleography was performed in adult CI subjects who were recipients of Advanced Bionics' Bionics LLC precurved HiFocus MidScala or straight HiFocus SlimJ electrode arrays. ECochG responses were recorded from the most apical electrode contact during insertion. No changes to the insertions were made due to ECochG monitoring. No information about insertion resistance was collected. ECochG drops were estimated as the change in amplitude from peak (defined as maximum amplitude response) to drop (largest drop) point after the peak during insertion was measured following the peak response. Audiometric thresholds from each subject were obtained before and approximately 1 month after CI surgery. The change in pure tone average for frequencies between 125 Hz and 500 Hz was measured after surgery. No postoperative CT scans were collected as part of this study. RESULTS: A total of 68 subjects from five surgical centers participated in the study. The study sample included 30 MidScala and 38 SlimJ electrodes implanted by approximately 20 surgeons who contributed to the study. Although a wide range of results were observed, there was a moderate positive correlation (Pearson Correlation coefficient, r = 0.56, p < 0.01) between the size of the ECochG drop and the magnitude of pure tone average change. This trend was present for both the MidScala and SlimJ arrays. The SlimJ and MidScala arrays produced significantly different hearing loss after surgery. CONCLUSION: Large ECochG amplitude drops observed during electrode insertion indicated poorer hearing preservation. Although the outcomes were variable, this information may be helpful to guide surgical decision-making when contemplating full electrode insertion and the likelihood of hearing preservation.

In Vitro Glycosylation of Membrane Proteins Using N-Glycosyltransferase.

Glycoproteins are post-translationally modified proteins that take part in nearly every biological process and make up a large percent of the proteome. N-Linked glycosylation can be performed by N-glycosyltransferase (NGT), which recognizes the consensus amino acid sequence, -Asn-X-Ser/Thr- (NXT), within the protein. The enzyme catalyzes glycosidic bond formation between the oligosaccharide donor, containing nucleoside phosphatase, and the amide nitrogen of the asparagine residue. The attachment of the sugar moiety can influence physiological and biological properties of the protein by affecting their folding, modulating interactions with other biomolecules, and modifying their functions at the cellular level. We are specifically interested in the properties of membrane glycoproteins, which are key components in a number of different disease states. Therefore, the use of in vitro protein glycosylation can help further evaluate the effects of the properties for these important macromolecules. In vitro studies of N-linked glycosylation were done in a stepwise fashion in a membrane-mimetic environment to confirm that the methods for glycosylating soluble proteins could be applicable to membrane proteins. Detergent and lipid systems were used since hydrophobic peptides and membrane proteins are insoluble in aqueous solvents. The stepwise method consisted of the glycosylation of a soluble 7-residue peptide, a hydrophobic WALP-NVT peptide, and a γ-sarcoglycan membrane protein, all of which contained the glycosylation site Asn-Val-Thr (NVT). Glycosylation of the samples was performed using Escherichia coli-expressed NGT from the Actinobacillus pleuropneumoniae genome, and a single sugar moiety of glucose, provided from a nucleotide-linked donor, was added to the glycosylation site. Gel electrophoresis, mass spectrometry, and NMR studies were used for the detection of glycosyltransferase activity and to show the attachment of a single glucose molecule. Our experiments demonstrated that small or large membrane proteins that contain an N-glycosylation consensus sequence can be glycosylated by NGT in membrane-mimetic environments.

Can an Imaging Marker of Consistency Predict Intraoperative Experience and Clinical Outcomes for Vestibular Schwannomas? A Retrospective Review.

Objective The main purpose of this article is to determine if vestibular schwannoma consistency as determined by tissue intensity on T2-weighted magnetic resonance imagings (MRIs) is predictive of intraoperative experience and postoperative clinical outcomes. Study Design Retrospective chart review. Setting Tertiary referral center. Patients Seventy-seven patients diagnosed with vestibular schwannomas who were treated with microsurgical resection. Intervention Diagnostic. Main Outcome Measures Intraoperative measures include totality of resection, surgical time and cranial nerve VII stimulation and postoperative measures include House-Brackmann grade and perioperative complications. Results Tumor consistency determined via tissue intensity on MRI was only found to correlate with surgical time, with a softer tumor being associated with a longer surgical time ( p < 0.0001). However, this was primarily driven by tumor volume with larger tumors being associated with longer surgical time based on multivariate analysis. None of the other intraoperative or postoperative measures considered were found to correlate with tumor consistency. Conclusions Tumor consistency determined by MRI is not predictive of intraoperative experience or postoperative outcomes in vestibular schwannomas. Tumor volume is the strongest driver of these outcome measures as opposed to tumor consistency.

A Longitudinal Comparison of Environmental Sound Recognition in Adults With Hearing Aids Before and After Cochlear Implantation.

Purpose The aims of this study were (a) to longitudinally assess environmental sound recognition (ESR) before and after cochlear implantation in a sample of postlingually deafened adults and (b) to assess the extent to which spectro-temporal processing abilities influence ESR with cochlear implants (CIs). Method In a longitudinal cohort study, 20 postlingually deafened adults were tested with hearing aids on the Familiar Environmental Sound Test-Identification and AzBio sentences in quiet pre-CI and 6 months post-CI. A subset of 11 participants were also tested 12 months post-CI. Pre-CI spectro-temporal processing was assessed using the Spectral-temporally Modulated Ripple Test. Results Average ESR accuracy pre-CI (M = 63.60%) was not significantly different from ESR accuracy at 6 months (M = 65.40%) or 12 months (M = 69.09%) post-CI. In 11 participants (55%), however, ESR improved following implantation by 10.91 percentage points, on average. Pre-CI ESR correlated moderately and significantly with pre-CI and 12-month post-CI AzBio scores, with a trend toward significance for AzBio performance at 6 months. Pre-CI spectro-temporal processing was moderately associated with ESR at 6 and 12 months post-CI but not with speech recognition post-CI. Conclusions The present findings failed to demonstrate an overall significant improvement in ESR following implantation. Nevertheless, more than half of our sample showed some degree of improvement in ESR. Several environmental sounds were poorly identified both before and after implantation. Spectro-temporal processing ability prior to implantation appears to predict postimplantation performance for ESR. These findings indicate the need for greater attention to ESR following cochlear implantation and for developing individualized targets for ESR rehabilitation. Supplemental Material https://doi.org/10.23641/asha.13876745.

Perception of Environmental Sounds in Cochlear Implant Users: A Systematic Review.

Objectives: Improved perception of environmental sounds (PES) is one of the primary benefits of cochlear implantation (CI). However, past research contains mixed findings on PES ability in contemporary CI users, which at times contrast with anecdotal clinical reports. The present review examined extant PES research to provide an evidence basis for clinical counseling, identify knowledge gaps, and suggest directions for future work in this area of CI outcome assessment. Methods: Six electronic databases were searched using medical subject headings (MeSH) and keywords broadly identified to reference CI and environmental sounds. Records published between 2000 and 2021 were screened by two independent reviewers in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement to identify studies that met the inclusion criteria. Data were subsequently extracted and evaluated according to synthesis without-meta-analysis (SWiM) guidelines. Results: Nineteen studies met the inclusion criteria. Most examined PES in post-lingually implanted adults, with one study focused on pre/perilingual adults. Environmental sound identification (ESI) in quiet using open- or closed-set response format was most commonly used in PES assessment, included in all selected studies. ESI accuracy in CI children (3 studies) and adults (16 studies), was highly variable but generally mediocre (means range: 31-87%). Only two studies evaluated ESI performance prospectively before and after CI, while most studies were cross-sectional. Overall, CI performance was consistently lower than that of normal-hearing peers. No significant differences in identification accuracy were reported between CI candidates and CI users. Environmental sound identification correlated in CI users with measures of speech perception, music and spectro-temporal processing. Conclusion: The findings of this systematic review indicate considerable limitations in the current knowledge of PES in contemporary CI users, especially in pre/perilingual late-implanted adults and children. Although no overall improvement in PES following implantation was found, large individual variability and existing methodological limitations in PES assessment may potentially obscure potential CI benefits for PES. Further research in this ecologically relevant area of assessment is needed to establish a stronger evidence basis, identify CI users with significant deficits, and improve CI users' safety and satisfaction through targeted PES rehabilitation.

Digital Otoscopy Videos Versus Composite Images: A Reader Study to Compare the Accuracy of ENT Physicians.

OBJECTIVES/HYPOTHESIS: With the increasing emphasis on developing effective telemedicine approaches in Otolaryngology, this study explored whether a single composite image stitched from a digital otoscopy video provides acceptable diagnostic information to make an accurate diagnosis, as compared with that provided by the full video. STUDY DESIGN: Diagnostic survey analysis. METHODS: Five Ear, Nose, and Throat (ENT) physicians reviewed the same set of 78 digital otoscope eardrum videos from four eardrum conditions: normal, effusion, retraction, and tympanosclerosis, along with the composite images generated by a SelectStitch method that selectively uses video frames with computer-assisted selection, as well as a Stitch method that incorporates all the video frames. Participants provided a diagnosis for each item along with a rating of diagnostic confidence. Diagnostic accuracy for each pathology of SelectStitch was compared with accuracy when reviewing the entire video clip and when reviewing the Stitch image. RESULTS: There were no significant differences in diagnostic accuracy for physicians reviewing SelectStitch images and full video clips, but both provided better diagnostic accuracy than Stitch images. The inter-reader agreement was moderate. CONCLUSIONS: Equal to using full video clips, composite images of eardrums generated by SelectStitch provided sufficient information for ENTs to make the correct diagnoses for most pathologies. These findings suggest that use of a composite eardrum image may be sufficient for telemedicine approaches to ear diagnosis, eliminating the need for storage and transmission of large video files, along with future applications for improved documentation in electronic medical record systems, patient/family counseling, and clinical training. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E1668-E1676, 2021.

Lumbar drains: Practical understanding and application for the otolaryngologist.

INTRODUCTION: Lumbar drains are frequently used in patients with otolaryngologic concerns. These can be used therapeutically or prophylactically with the primary purpose being to modulate CSF pressure. Within otolaryngology, lumbar drains are most frequently used for cerebrospinal fluid leaks - either due to cerebrospinal fluid fistulas or in skull base surgery as these allow for potential healing of the defect. While not typically placed by otolaryngologists, a basic understanding of lumbar drains is beneficial in the context of patient management. MANAGEMENT: A lumbar drain is inserted into the intrathecal space in a patient's lumbar spine. Though considered to be a benign procedure, complications are relatively frequent, and adjustment or replacement of the drain may be required. Complications include infection, epidural bleeding, retained hardware, sequelae of relative immobility, or may relate to over-drainage, ranging from mild headache to cranial neuropathies, altered mental status, pneumocephalus, intracranial hemorrhage, and death. While in place, neurologic exams should be performed routinely and should include motor and sensory exams of the lower extremities. A patient should be monitored for fevers, nuchal rigidity, and other signs of infection or meningitis. The CSF fluid should be grossly examined to identify changes, but routine laboratory tests are not typically run on the fluid itself. Drainage rates will vary usually between 5 and 20 mL per hour and must be frequently reassessed and adjusted based upon signs of intracranial hypotension. Drains should be removed when appropriate and should not be left in more than 5 days due to the increased infectious risk. CONCLUSION: Lumbar drains are important tools used in patients with otolaryngologic pathologies. Otolaryngologists and otolaryngology residents should be familiar with these catheters to determine if they are working correctly and to identify adverse effects as early as possible.

Electrocochleography During Translabyrinthine Approach for Vestibular Schwannoma Removal.

HYPOTHESIS: Intraoperative electrocochleography (ECochG) can differentiate hair cell and neural dysfunction caused by a vestibular schwannoma (VS) and help define the site of lesion as peripheral or central to the spiral ganglion. BACKGROUND: Hearing loss in patients with a VS can be caused by both sensory (cochlear) and neural dysfunction. METHODS: Round-window ECochG using low and high-frequency tone bursts was performed in 49 subjects with a VS. Responses were analyzed for magnitude, spectrum, and shape of the time waveform. Components examined included the cochlear microphonic, auditory nerve neurophonic, compound action potential (CAP), and summating potential (SP). RESULTS: Variability in the summed response magnitudes across frequency, or "total response" (ECochG-TR), varied from 0.1 to 100 µV. Responses were larger for lower frequencies. Subjective estimates revealed a wide range of neural contributions from the auditory nerve neurophonic to low frequencies and the CAP to high frequencies. Cases with larger CAPs had smaller SPs. The correlation of ECochG-TR, with word recognition score (WRS), was moderate (r = 0.67), as well as the correlation between pure-tone averages and ECochG (r = 0.63). The cochlea remained functional in two cases of sudden sensorineural hearing loss with 0% WRS. CONCLUSION: Reduced ECochG-TR and neural activity in many cases indicates both sensory and neural deficits. Smaller SPs when CAPs are present indicate a neural contribution to the SP. Good cochlear function with 0% WRS, and cases of sudden sensorineural hearing loss with retained cochlear function, indicate retrocochlear effects, typically proximal to the spiral ganglion cells.

Safety-relevant environmental sound identification in cochlear implant candidates and users.

OBJECTIVES/HYPOTHESIS: To compare the identification of safety-relevant environmental sounds between experienced cochlear implant (CI) users and CI candidates. STUDY DESIGN: Cross-sectional. METHODS: A sample of 19 adult, postlingually deaf CI candidates (CI-Cs), 47 experienced CI users (CI-Es), and a control group of 37 age-matched normal-hearing adults were assessed using the Familiar Environmental Sounds Test-Identification (FEST-I). A subset of 11 sounds relevant for safety were selected for analysis in the current study. RESULTS: Analysis of safety-relevant sound identification accuracy revealed no significant difference in safety-relevant environmental sound identification skills between CI-E and CI-C participants, with average scores of 68.1% and 67.9%, respectively. Both performed substantially lower than age-matched normal hearing adults (95.1%). A significant moderate negative correlation (-0.4) was found between safety-relevant sound accuracy and chronological age only in one group, the CI-E group (r = -0.4, P < .005). CONCLUSIONS: These findings fail to demonstrate superior performance in safety-relevant environmental sound identification among CI-Es compared with CI-Cs. Although preliminary, these findings suggest that identification of safety-relevant sounds is a significant area of weakness for both CI-Es and CI-Cs, both of whom may benefit from rehabilitation. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1547-1551, 2020.