Otology/Neurotology

Access to Experienced CI, Surgeons and Audiology Is Socioeconomically Determined

Alexander Chern, MD (Presenter); Rahul K. Sharma; Anil K. Lalwani, MD

Introduction: Previous studies have identified socioeconomic disparities in access to cochlear implantation. This study examines socioeconomic determinants of access to experienced cochlear implant (CI) surgeons and postoperative audiologic care using New York Statewide Planning and Research Cooperative System data.

Method: Secondary analysis of a prospective claims database was performed. Adults (>18 years) who underwent cochlear implantation from 2010 to 2017 with at least 1 audiology visit claim within first year of implantation were observed. Multivariate logistic regression controlling for age, race/ethnicity, gender, and insurance status was used to predict frequency of audiology visits (>50th percentile in claims for audiology visits after cochlear implantation); CI, complications, and having been operated on by a high-volume surgeon (surgeon with >75th percentile in CI, claims over a 7-year period; 69 CI, surgeries/year).

Results: A total of 796 adult subjects (53.5% female, 44.2% non-White) were analyzed. Average age of implantation was 60.7 years; 30.2% had their CI, from a high-volume surgeon. On multivariate logistic regression, non-White race (odds ratio 0.19; 95% CI, 0.11–0.32, p75th percentile volume: 0.12, 0.03–0.40, p50th percentile in postoperative audiology visit claims, 25–50th percentile volume: 1.97, 1.12–3.53, P = .02; 50th–75th percentile volume: 4.15, 2.51–6.99, P < .01).

Conclusion: Among patients undergoing CI, access to experienced surgeons and frequent postoperative audiology visits are in part determined by socioeconomic factors. This has important consequences as more experienced surgeons had fewer complications. Future studies are needed to address barriers to experienced care for CI, recipients.

Application of Machine Learning to Predict Hearing Outcome in Tympanoplasty

Hajime Koyama, MD (Presenter); Tsukasa Uranaka, MD; Akinori Kashio, MD, PhD; Yu Matsumoto, MD, PhD; Tatsuya Yamasoba, MD, PhD

Introduction: This study aims to investigate the applicability of machine learning technique to predict the postoperative outcomes of tympanoplasty for chronic otitis media patients.

Method: A retrospective analysis was conducted. A total of 105 chronic otitis media patients (114 ears, mean age: 55.0 years) who received tympanoplasty from January 2017 to December 2020 at a tertiary hospital were included in this study. Favorable outcome was defined as a postoperative air–bone gap of <15 dB. The accuracy of predicting the outcome was compared between a classical scoring model and a machine learning model. In the classical scoring model, ears were stratified by middle ear risk index (MERI) into mild (MERI 0–3, n = 80) and moderate (MERI 4–7, n = 34) groups. In the machine learning model, age, preoperative air–bone gap, middle ear granulation or effusion, otorrhea, previous surgery, ossicular status, lotion of the tympanic perforation, and smoking were selected as independent variables. Data were randomly divided into training and test set. Random forest algorithm was applied to analyze the data, and prediction accuracies of classification in training and test set were calculated.

Results: In total, 39 ears had middle ear granulation or effusion. Some 56 ears had otorrhea, and 21 ears had previous operation. Four ears had ossicular chain problem, and 37 patients were smokers. The average postoperative air–bone gap was 14.1 ± 11.2 dB, and 75 (65%) ears had favorable outcomes. The prediction accuracy by MERI scoring was 62.3%, and those in the random forest algorithm in train data and test data were 86.1% and 74.3%, respectively.

Conclusion: The machine learning technique has the potential to predict the postoperative outcomes of tympanoplasty or chronic otitis media patients.

Association of Pediatric Hearing Quality and Sports Participation: A Population-Based Study

Renata M. Knoll, MD (Presenter); Elliott D. Kozin, MD; Neil Bhattacharyya

Introduction: Sports-related injuries, such as concussion, during childhood may result in negative developmental consequences. Auditory dysfunction is recognized to be a possible sequela of sports-related concussion; however, few large-scale epidemiological studies have quantified the association between hearing quality and sports-related activity in the pediatric population.

Method: The National Health and Nutrition Examination Survey for the 2015–2016 cycle was utilized to determine the association of sports activities and hearing quality in children aged 5 to 15 years. Sports for the present analysis included basketball, American football, soccer, baseball, and swimming. Hearing was qualitatively assessed based on responses from the audiology questionnaire and grouped into 2 groups: “excellent” or “less than excellent” hearing. Deafened patients were excluded. The distribution of quality of hearing was compared with a chi-square test.

Results: Among the estimated 47.1 million children that were assessed (52.2% male; mean age, 10.2 years), 63.4% (29.9 million) were physically active and practicing basketball (n = 8.1 million), football (n = 5.3 million), soccer (n = 6.6 million) baseball (n = 4.3. million), and swimming (n = 5.6 million). Subjective abnormal hearing quality was more frequent among children who played football compared with those that did not (36.5% and 26.8%, respectively; odds ratio: 1.56 [95% CI, 1.23-2.00]; P = .001). Other sports, such as basketball and soccer, did not have this association with hearing quality (P = .496 and P = . 852, respectively).

Conclusion: Our findings suggest a notable association between practice of a potentially high-concussion sport and hearing quality. Children practicing football are 1.56 times more likely to report abnormal hearing quality.

Automated CT Temporal Bone Segmentation for Applications in Neurotologic Surgery

Alexander Lu (Presenter); Andy S. Ding; Zhaoshuo Li; Jeffrey H. Siewerdsen, MS, PhD; Russell H. Taylor, PhD; Francis X. Creighton, MD

Introduction: Semiautonomous and autonomous surgical robots have the potential to improve surgical safety in neurotology. However, such methods require automated, efficient, and accurate segmentations of preoperative imaging for registration to patient anatomy. This study investigates the accuracy of an automated method to segment relevant temporal bone anatomy in cone-beam computed tomography (CT).

Method: We developed a computational pipeline around the symmetric normalization registration method, producing an automated pipeline that predicts segmentations of a new image based on a labeled atlas. To evaluate accuracy, we manually segmented each of 16 deidentified high-resolution cone-beam CT images of the temporal bone, labeling each voxel corresponding to an anatomical region (eg, ossicles, labyrinth, facial nerve, external auditory canal, dura, etc) with a different tag. Predicted segmentations from our automated method were compared against this ground truth using Hausdorff distance and Dice score. The right-sided template was reflected across the midline to evaluate the left side. Runtimes were documented to determine computational requirements of this method.

Results: The average Hausdorff distances and Dice coefficients between predicted and ground truth were as follows: malleus (0.106 ± 0.007 mm, Dice: 0.836 ± 0.014), incus (0.129 ± 0.029 mm, Dice: 0.846 ± 0.029), stapes (0.257 ± 0.214 mm, Dice: 0.353 ± 0.140), labyrinth (0.175 ± 0.081 mm, Dice: 0.847 ± 0.063), and facial nerve (0.761 ± 0.413 mm, Dice: 0.551 ± 0.101). A 24-core machine with 8-GB RAM completed 1 registration in 5 minutes.

Conclusion: We demonstrate submillimeter accuracy for automated segmentation of temporal bone anatomy compared with hand-segmented ground truth using our template registration pipeline. This method is not limited by the significant dependence on training data volume that plagues more complex deep learning models. Rapid runtime and low computational requirements further underscore this method’s translational potential.

Catchment Profile of Large Cochlear Implant Centers in the US

Ashley M. Nassiri, MD, MBA (Presenter); Elizabeth L. Perkins, MD; Meredith A. Holcomb, AuD; Andrea L. Bucker, AuD; Aniket A. Saoji, PhD; Matthew L. Carlson, MD

Introduction: In an effort to better understand factors influencing the under-utilization of cochlear implants (CIs) in the US, we sought to characterize the catchment area and patient profile of high-volume CI, centers.

Method: All patients undergoing CI, surgery at four participating large CI, centers between 2015 and 2020 were retrospectively identified. The patients’ home addresses were used to calculate travel distances and determine urban vs rural residential areas (urban area defined as >1000 individuals/square mile).

Results: Over the 5-year study period, 4489 CIs were implanted in 3234 unique recipients (1042 children and 2192 adults). Nearly 39% of patients underwent bilateral implantation (sequential or simultaneous), 63% of whom were children. The annual number of unique patients undergoing CI, increased by 23% over the 5-year study period. Patients traveled an average of 114 miles each way, and adult patients were more likely to travel farther compared with pediatric patients (127 vs 87 miles, respectively; P < .001). While 68% of patients resided outside of a 50-mile radius, the extent of patient reach was largely limited to a 200-mile radius, which encompassed 88% of patients. Rural residents comprised 65% of the patient population and traveled farther compared with urban residents (123 vs 100 miles, P < .001).

Conclusion: While large CI, centers serve geographically dispersed patient populations, patient access beyond a 200-mile radius is limited, potentially creating watershed areas between centers. Outreach programs aimed to expand catchment areas must take travel burden and access to local care into consideration.

Characteristics of Patients With Homozygous Mutations in the Otoferlin Gene

Eugenia Carmela López Simón (Presenter); Patricia Corriols Noval; Minerva Rodríguez Martín; Ramón Cobo Díaz; Belen Salvatierra Virio

Introduction: Auditory neuropathy secondary to p.Gln829X mutation in the otoferlin gene (OTOF) is the third genetic cause of prelocution deafness in Spain’s population. Otoacoustic emissions (OAEs) are preserved while brainstem auditory evoked potentials (BAEPs) appear absent or severely distorted.

Method: A retrospective and descriptive study of the clinical and audiological characteristics of all patients with genetic testing of p.Gln829X mutation (OTOF gene) was made from 2000 to 2020. The genetic diagnostic was carried out by the Molecular Genetics Unit (Ramon and Cajal Hospital) and IMOMA (Asturias).

Results: We genetically screened 26 patients from 5 different families with a diagnosis of congenital profound hearing loss due to otoferlin gene mutation in 1 member. There was a total of 14 men (54%) and 12 women (46%), born between 1921 and 2017. Some 35% of subjects did not carry the mutation and therefore had normal hearing; 27% were heterozygous carriers of Q829X mutation with normal hearing, and the remaining 35% carried Q829X mutation homozygosity, suffering from bilateral profound deafness. We highlight the fact of 1 patient with hearing loss and the mutation in heterozygosis. Otoscopy examination was normal in 100%, and apart from 1 case, the OAEs were preserved. In contrast, BAEPs were altered in every patient. According to the treatment, 50% used hearing aids and the other 50% were cochlear implanted with good hearing levels.

Conclusion: Most patients with Q829X heterozygous mutation in the otoferlin gene have normal hearing. However, the homozygous form manifests in bilateral profound deafness with normal OAEs after birth. The moderately high prevalence of this mutation in the Spanish population could produce a significant false-negative rate in newborn hearing screening programs using OAEs. For all of these reasons, it is important to suspect it in order to place cochlear implants as soon as possible.

Computational Modeling of Cholesteatoma Pathogenesis

Sudeepti Vedula (Presenter); Marissa Ilaria; Mohammed Hussain; Joseph Salguero; Kabeer Munjal; Robert Jyung, MD

Introduction: Cholesteatoma is characterized by accumulation of invasive and destructive keratinizing epithelium in the temporal bone. Although the retraction pocket (RP) theory of pathogenesis is well accepted, a detailed, stepwise description of pathogenic events after RP formation is lacking. We propose that the unique migratory nature of the tympanic membrane/external auditory canal skin heavily contributes to cholesteatoma formation. We used computational engineering methods to explore this possibility.

Method: For a base structure, we used a finite element model (FEM) of the tympanic membrane and middle ear (TM/ME) published by the University of Antwerp. SolidWorks software was used to make the FEM deformable, and MATLAB software was used to model migrating epithelium, which was overlayed on the deformable TM/ME model.

Results: Our deformable TM SolidWorks model had a 9-mm diameter, 0.1-mm thickness, and material properties with Young’s modulus 3.4 × 1 N/m² and a mass density of 1.2 × 1 kg/m². Squamous epithelium migrated at a rate of 0.097 µm/min (consistent with in vivo rates), expanding radially from the TM center toward the annulus. When confronted with a fixed obstacle, the migrating epithelium showed a buckling pattern. Deformations induced in the TM resulted in altered patterns of epithelial migration.

Conclusion: This is the first attempt to model acquired cholesteatoma formation using computation methods. We explored interactions between RP formation and epithelial migration, which should not be ignored when proposing mechanisms for cholesteatoma pathogenesis. Computational modeling offers the optimal medium to explore our hypothesis. Given that no computational model existed, we developed this model to fill a knowledge gap in the ongoing pursuit of a complete theory of cholesteatoma pathogenesis.

Developing a Regional Cochlear Implant Consortium: Do Complication Profiles Differ?

Matthew R. Bartindale, MD (Presenter); Kevin Peterson; Jeffrey Singh; Ariana Kenney; Douglas D. Backous, MD

Introduction: We developed a regional cochlear implant (CI) consortium to expand patient access to expert surgical care with audiology services closer to home. We hypothesize that this model offers a safe and viable practice model.

Method: This retrospective study at a tertiary center included adult patients who received a unilateral CI, by a single surgeon from July 2017 to October 2019. Preoperative evaluation and postoperative medical care were coordinated in the patient’s locale as needed. Audiology care was performed by independent consortium clinics in the patient’s home community. Demographics, comorbidities, otologic history, and complications were documented for each patient.

Results: A total of 110 patients received a CI. Some 71 received audiologic care from consortium clinics and 39 at our clinic. The average distance traveled for surgical care was 107.2 miles for local and 34.4 miles for consortium patients (P = .0001). Consortium patients were more likely to be older (75.4 years vs 69.6 years, P = .0296), have diabetes mellitus (18.3% vs 4.2%, P = .0381), and have a cardiac history (32.3% vs 9.9%, P = .0092). No significant difference in patient gender (P = .5285), autoimmune conditions (P = .2105), smoking status (current P = .0623, former P = .1691), anticoagulation status (P = .0543), or body mass index (P = .4539) were noted. There was no significant difference in complication rates between the 2 groups (P = .8540).

Conclusion: More comorbidities were noted in the consortium group, yet there was no significant difference in complication rates between the 2 groups. Preoperative coordination of medical issues allowed us to expand CI, access beyond our traditional reach at our tertiary center. This model is a viable way to safely expand CI, care to new groups of patients.

Diagnostic Yield of CT Imaging in Pulsatile Tinnitus

Natalia Kuhn, ENS, MC, USNR (Presenter); Matthew Studer; Candace E. Hobson, MD

Introduction: The workup of pulsatile tinnitus (PT) generally involves computed tomography (CT) or magnetic resonance imaging; however, the etiology of PT often remains unknown. The goal of this study is to quantify the rate at which CT yields a diagnosis for patients with PT, as well as to identify factors that may predict diagnostic imaging.

Method: This is a retrospective review of patients presenting to a tertiary care center with pulsatile tinnitus who underwent CT temporal bones and/or CT angiography head/neck between 2015 and 2020. Variables that were analyzed include patient demographics, PT laterality and duration, the ability to modify PT with venous compression, treatment, and symptom resolution after treatment. The diagnostic yield of CT scanning and the specific diagnoses were recorded.

Results: A total of 136 patients (80.8% female) met inclusion criteria, with an average age of 50.3 years; 75.7% (103) had unilateral PT, 19.9% (27) had bilateral PT. and 4.4% (6) had unspecified laterality. Of the patients, 30.9% (42) could modify their PT with venous compression of the internal jugular vein. A specific diagnosis was found on CT in 39% (53) of patients. The breakdown of diagnoses in those 53 patients was 42.2% (24) sigmoid sinus dehiscence/diverticulum, 32.1% (17) skull base dehiscence, 17% (9) idiopathic intracranial hypertension, 11.3% (6) semicircular canal dehiscence, 9.4% (5) dominant venous system, and 3.8% (2) other vascular findings. Some CTs yielded multiple diagnoses. Patients with modifiable PT were significantly more likely to have diagnostic CT imaging than patients with nonmodifiable PT (61.9% vs 29.0% , P < .002). Patients with diagnostic CTs had a significantly longer duration of symptoms than those with nondiagnostic CTs (37.6 vs 16.7 months, P = .048). Common surgical treatments included resurfacing, decompression and reconstruction of the sigmoid sinus, skull base, and semicircular canal; Diamox was a common medical treatment.

Conclusion: CT scanning is nondiagnostic in the majority of patients with PT. Diagnostic scans are more likely in patients with modifiable PT and in patients with a longer duration of symptoms.

Early Hearing Preservation Outcomes With New Slim Lateral Wall Electrode Using Electrocochleography

Amit Walia, MD (Presenter); Jacques A. Herzog, MD; Matthew A. Shew, MD; Cameron C. Wick, MD; Nedim Durakovic, MD; Craig A. Buchman, MD

Introduction: We assess early hearing preservation (HP) outcomes of patients implanted with the new Slim 20 lateral wall array (CI624); compare early HP outcomes with and without real-time electrocochleography (RT-ECochG); and explain the role of RT-ECochG feedback to improve HP. We believe this abstract is suitable for a late-breaking abstract as we are the first to report early HP outcomes for a new Slim 20 lateral wall electrode (CI624). Since the CI624’s release in May 2020, it is becoming increasingly popular among centers as a potential HP array. To our knowledge, there have not been any discussions at major conferences or published studies reviewing experiences with the CI624. Based on our early experience with 29 implantations using this electrode, we have found poor HP outcomes 1 month postoperatively with preservation in only 16 of the recipients. As a result, we began using real-time monitoring of cochlear health during the insertion (ie, electrocochleography [ECochG]) to potentially improve HP outcomes with the CI624. By using real-time ECochG (RT-ECochG) and particularly focusing on minimizing trauma at the end of insertion, we achieved superior early HP rates with this array (8/9 patients, 88.9%). Our preliminary data suggest that full insertion of the CI624 without ECochG results in unpredictable and relatively poor HP outcomes. We suspect that this is related to the CI624 being a longer electrode than previous hybrid arrays resulting in trauma to the apical-most hair cells and neural elements at full insertion. Thus, RT-ECochG may be required for predictable early HP using the CI624. As a result of the COVID-19 pandemic, we were unable to achieve sufficient implantations for submission of an abstract in January 2021. However, we have now performed 9 implants with the CI624 in the past 6 months using RT-ECochG for HP candidates. We believe that our experience with and without ECochG has resulted in an early critical finding that may influence how this implant is used in HP candidates.

Methods: A longitudinal study was designed with postlinguistically deafened adults undergoing implantation with CI624 from 2020 to 2021. Pure-tone audiometry preoperatively and 1 month postoperatively were obtained. HP was defined as low-frequency pure-tone average (LFPTA; 125, 250, 500 Hz) <80 dB. Intracochlear RT-ECochG was used to guide insertion for 9 patients. When there was >5 µV ECochG response drop, array adjustments (ie, withdrawal ~1 mm, 5° anti-modiolar rotation) were made to facilitate response recovery.

Results: A total of 38 implants were performed. There was no scalar translocation on postoperative CT scans and mean apical insertion angle was 338.1° ± 86.4°. Full insertion was performed in most cases; however, partial insertion was performed if the RT-ECochG response dropped during insertion of the final 3 electrodes (n = 4). Of the 29 patients where RT-ECochG was not used, 16 (55.2%) had low-frequency HP postoperatively with preoperative LFPTA 42.4 ± 16.4 dB and threshold shift to 83.9 ± 27.8 dB. Among the 9 patients where RT-ECochG was used, 8 (88.9%) had low-frequency HP postoperatively with preoperative LFPTA 46.5 ± 16.0 dB and threshold shift to 62.6 ± 19.0 dB. Difference between threshold shift postoperatively with and without RT-ECochG was significant (P = .002, Mann-Whitney U test).

Conclusion: RT-ECochG–guided insertion may be required for consistent HP outcomes following CI624 implantation. This may allow the surgeon to decide the depth of electrode insertion in the effort to preserve low-frequency hearing. Further investigation is needed to evaluate whether long-term HP can be maintained using CI624.

Educational Benefit of ORBEYE Exoscope vs Microscope in Otologic Surgery

Anya Costeloe (Presenter); Nathan C. Tu, MD; Seilesh C. Babu, MD

Introduction: This study examines whether visualizing otologic surgeries in a 3-dimensional exoscope view improves medical student and fellow educational experience.

Method: This was a prospective study at a teaching hospital performed between October 2019 and December 2020. Medical students on an ear, nose, and throat (ENT) rotation; ENT residents; and neurotology fellows were included. Surveys in 3 parts were administered including a baseline preobservation, after observing the first surgery with either exoscope or microscope and after observing the second surgery with the opposite device from the first surgery. The key outcome variables were image clarity, depth perception, level of motion sickness, understanding of middle ear anatomy and ability to identify the tympanic segment of the facial nerve, cochleariform process, oval window, and round window. Subjects graded their responses on a scale of 1 to 10 (1 worst, 10 best). Statistical analysis was performed, and a P value <.05 was considered significant.

Results: In total, 22 participants completed surveys. There was a significant improvement in the comprehension of middle ear anatomy after observation with the exoscope (P = .002) but not with the microscope (P = .762). The clarity and depth perception were significantly better with the exoscope (P = .00000004, P = .000002), while there was slightly higher level of nausea with the exoscope (P = .015). Whether the exoscope or microscope was observed first did not affect preferred method or level of improvement. Overall, 95.5% of participants preferred the exoscope to the microscope. There was no significant difference in results between medical students, junior, and senior residents, illustrating that the exoscope benefits all levels of medical education.

Conclusion: This is the first study comparing the educational benefit of the exoscope compared with the microscope in otolaryngology. The results demonstrate that the exoscope allows for better visualization of the surgery and anatomy in medical education.

Electrode Position and Clinical Outcomes in Revision Cochlear Implantation

Arianna R. Winchester (Presenter); Emily Kay-Rivest; Qianhui Shao; J. Thomas Roland Jr; Babak Givi, MD; Daniel Jethanamest

Introduction: Revision cochlear implantation (CI) is a rare scenario that poses unique challenges in achieving optimal electrode positioning and clinical outcomes. We investigated the frequency of revision CI, at our center with a focus on electrode array positioning and hearing outcomes.

Method: All adult and pediatric CI, from 2011 to 2020 were reviewed, and revision cases were selected. Demographics, indications for revision, radiologic and surgical details, complications, and audiologic outcomes were analyzed. Intraoperative radiographs were independently reviewed by 2 investigators to determine angular depth of insertion (aDOI) in primary and revision CI.

Results: During the study period, 88 ears in 69 patients (40 adults, 29 children) underwent revision CI. Indications included medical/surgical uses (infection, trauma, device migration, suboptimal insertion, retrocochlear lesions; 40, 45.5%), hard failure (33, 37.5%), and soft failure (15, 17%). Eleven patients (16%) required more than 1 revision; 1 required 3 revisions. The average time to revision was 4.4 years. A device from the original manufacturer was used in 81.4% of cases (n = 86). Audiologic outcomes after revision improved significantly when comparing the mean best sentence in quiet scores before and after revision (from: 67.0 to: 89.5, p45° shallower than original insertions).

Conclusion: Revision CI, surgery is overall infrequent but generally leads to improved clinical outcomes. Most revisions are due to hard failures and medical/surgical uses, in which the success rate in improving hearing is high. Revision electrode insertions achieve a comparable depth to primary insertions.

Ergonomics of Otologic Surgery: Endoscope vs Microscope

Annie E. Arrighi-Allisan (Presenter); Katherine L. Garvey; Kevin Wong, MD; Ameya A. Jategaonkar; Maura K. Cosetti, MD; Alfred-Marc Iloreta, MD

Introduction: The comparative postural health of surgeons performing endoscopic and microscopic otologic surgeries has been a topic of active debate, with many nascent or anecdotal reports suggesting the latter encourages suboptimal ergonomics. Using inertial body sensors to measure joint angles, this study sought to objectively evaluate and compare the ergonomics of trainee and attending surgeons during endoscopic and microscopic otologic surgeries.

Method: Six subjects (4 trainees, 2 attendings) performed 15 otologic surgeries (9 microscopic, 6 endoscopic) while wearing 11 inertial measurement units (IMU) affixed to either side of each major joint. IMU data, sampled at 128 Hz, were used to calculate joint angles. Ideal neck and trunk joint angles (ie, <10° in either direction) were determined by the validated Rapid Entire Body Assessment tool. Positive angles indicate joint flexion, while negative angles signify extension. Subjects completed a modified NASA Task Load Index to assess mental and physical exertion and pain after each surgery. Komogorov–Smirnov test was used to confirm normality, and Student t test was employed to detect differences between groups.

Results: Trainees demonstrated significantly more neck (10.92° vs −4.79°, P = .05) and back (16.48° vs 3.66°, P = .01) flexion during microscopic surgeries compared with endoscopic surgeries. However, these differences were not significant when attending neck and back angles were included in the analyses (neck: 5.26° microscopic vs −4.79° endoscopic, P = .119; back: 4.41° microscopic vs 3.66° endoscopic, P = .46). Levels of mental, physical, and temporal demand and pain did not differ significantly between endoscopic and microscopic techniques or between trainee and attending surgeons.

Conclusion: Our data suggest that trainees operate with higher-risk neck and back positions when performing microscopic otologic surgery compared with endoscopic cases. This difference does not endure when accounting for attending ergonomic data, suggesting that experienced otologists may adopt healthier compensatory posture over time.

Factors Associated With Limited Auditory Outcomes Following Adult Cochlear Implantation

Erika Leec (Presenter); Jordan Hochman; Justyn Pisa

Introduction: Many patients are successful in achieving useful hearing sensation after cochlear implantation (CI). However, performance varies widely, and a proportion of patients have limited audiometric outcomes. While there are some well-documented determinants of poor performance, there remains a cohort of patients who do not meet expectations. Preoperative prognostition is desirable to temper expectations, ensure value of the intervention, and reduce risk where possible. The objective of the study is to evaluate variables associated with the most limited speech outcomes following CI.

Method: We performed a retrospective review of a single CI, program’s cohort of (344 ears) patients implanted between 2011 and 2018 whose 1-year postimplantation AzBio scores fall 2 standard deviations below the median. Exclusion criteria include skullbase pathology, pre/perilingual deafness, cochlear anatomic abnormalities, English as an additional language, and limited electrode insertion depth. Overall, 26 patients were identified.

Results: The study population’s postimplantation net mean AzBio score is 18% compared with the program’s 47% (P < .001). This group is older (71.8 vs 59.0 years, P < .001) with a longer duration of hearing loss (26.4 vs 18.0 years, P < .01) compared with the general cohort. Preoperative AzBio scores are 14% lower (P < .001). Escalating comorbid status was associated with worse performance (P < .05).

Conclusion: Older patients with a longer duration of hearing loss were found to have more limited performance. Net benefit tended to decrease with comorbidity. The importance of a lower preoperative AzBio score is unclear but possibly relates to age and duration of impairment.

Gene Therapy for Hair Cell Regeneration: Review of the First in Man Inner Ear Gene Therapy Trial

Hinrich Staecker, MD, PhD (Presenter); Douglas E. Brough, MD; Lawrence Lustig, MD; Charles Della Santina, MD; Kevin Sykes, MD; Lloyd Klickstein, MD

Introduction: We review results of CGF166 delivery to the inner ear, discuss the challenges of developing molecular therapeutics for the inner ear, and understand the process of developing novel therapeutics. We have just finished a database lock on our last long-term follow-up patients for this phase 1 trial.

Methods: Using an Ad5-based vector system, we delivered the human atonal homolog hath1 driven by the glial fibrillary acidic protein promoter to the inner ear via a laser fenestration of the stapes footplate. Inclusion criteria were based on pure-tone hearing thresholds between 125 and 8000 Hz in adults up to age 75 years without a history of genetic hearing loss. Patients with conductive hearing loss and Ménière’s disease were excluded. Using a dose escalation design 20 to 60 µL of concentrated vector solution were infused. Outcomes measures included pure-tone hearing thresholds from 125 Hz to 16,000 Hz, speech discrimination, auditory brain stem responses, vestibulo-occular reflexes, caloric testing, and subjective visual vertical. Patients were followed for 6 months after vector delivery. Additional testing included serial magnetic resonance imaging scanning to look for cochlear inflammation and determination of anti-Ad5 titers.

Results: Of the initial cohort there were 3 responders and no significant adverse events. No patients with vestibular deficits were enrolled, and there was no change in vestibular function. Infusion of vector through the footplate was tolerated, and no change in conductive hearing loss was seen as a result of the procedure. Based on scaling calculations, vector dose infused was at the lower end of the predicted effective dose.

Conclusion: Infusion of molecular therapeutics via the stapes footplate is feasible and overall safe. There were some responders suggesting that manipulation of the atonal regulatory pathway can induce hair cells regeneration. Improvements in patient selection and delivery are needed.

Hearing Aids Enhance Music Enjoyment in Individuals With Hearing Loss

Alexander Chern, MD (Presenter); Michael W. Denham, MPhil; Rahul K. Sharma; Alexis S. Leiderman; Anil K. Lalwani, MD

Introduction: Patients with hearing loss (HL) exploring rehabilitation with hearing aids (HAs) frequently express concern about the impact of HAs on music enjoyment; the potential impact of HL and HA use on music enjoyment is poorly studied. Our study investigates music appreciation in HA users with varying levels of HL.

Method: A cross-sectional music enjoyment survey was distributed to adult (>18 years) bilateral HA users recruited from July 2020 to January 2021. Exposure variables include HL (better ear pure-tone average [PTAB]) and speech discrimination (word recognition scores [WRS]) based on most recent audiogram. Outcome variables included self-reported, validated measures of music enjoyment (pleasantness, musicality, naturalness) with and without HAs assessed with a visual analog scale (0–10; 10 indicates the highest level of enjoyment, 0 the least). Information on music background/preferences, HA usage, and demographics were also collected.

Results: A total of 77 bilateral HA users completed the study. The mean (SD) age was 65.2 (18.2) years; 46 (59.7%) were female. Mean (SD) PTAB was 56.0 (15.3) dB. Thirteen (16.9%) subjects had mild HL (PTAB 26–40 dB), 50 (64.9%) moderate to moderately severe HL (PTAB 41–70 dB), and 14 (18.2%) severe HL or worse (PTAB ≥71 dB). The mean (SD) length of HA use was 17.9 (14.6) years. Among all subjects, HAs (compared with no HAs) provided increased self-reported enjoyment of music in pleasantness (HA 6.99, no HA 5.69, P < .01), musicality (HA 7.51, no HA 6.12, P < .01), and naturalness (HA 6.88, no HA 5.92, P = .01). In multivariable regression, increasing severity of HL and worsening WRS were associated with decreased self-reported music enjoyment (adjusted P < .05) across all measures with and without HAs, adjusting for sex, age, education, race, HA type, age of HL diagnosis, duration of HL, duration of HA use, musical preference, and musical experience.

Conclusion: HA users report increased music enjoyment when using HAs compared with without HAs. However, the increased severity of HL and worsening WRS were independently associated with decreased self-reported music enjoyment both with and without HAs.

Hearing Durability and Trajectory After Radiosurgery for Vestibular Schwannoma

Christian Fritz (Presenter); Dennis Bojrab II, MD; Nathan C. Tu, MD; Christopher A. Schutt, MD; Seilesh C. Babu, MD

Introduction: We stratify patients into groups according to their baseline hearing function and analyze hearing outcomes following radiosurgical treatment of vestibular schwannoma (VS).

Method: This retrospective case series was performed in a tertiary neurotology referral center on patients treated with gamma knife radiosurgery (GKRS) for VS between March 2007 and March 2017. Exclusion criteria included pretreatment American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) class C/D hearing level, neurofibromatosis type II, history of previous surgical resection, and follow-up less than 1 year. The main outcome measure was hearing function assessed both by preservation of serviceable hearing (AAO-HNS class A/B) and by preservation of baseline hearing (≤20 dB change in pure-tone average [PTA]) after GKRS.

Results: A total of 93 patients were included in this study. The median duration of audiometric follow-up was 41 months (interquartile range, 19–81). Patients with pretreatment class A hearing status maintained serviceable hearing for a longer duration in the posttreatment period (P = .005) yet did not maintain hearing to within 20 dB of baseline for a longer duration than patients with class B hearing (P =.294). Analysis of changes in PTA after radiosurgery revealed a common hearing trajectory comprised of an acute, rapid decline in function, followed by stabilization, and then a delayed phase of slow decline after 36 months. Patients with better pretreatment hearing (WRS of 100%) experienced a more precipitous initial decline in hearing function than the group of patients with worse pretreatment hearing (WRS <100%; P = .033).

Conclusion: Normalization to baseline hearing using the quantitative PTA-based outcome measure afforded a more precise description of hearing trends compared with assessment by preservation of serviceable hearing. An understanding of year-by-year hearing trajectories and the concept that patients with better hearing may experience a larger initial decline in hearing function (rise in PTA) could prove useful for counseling patients on hearing expectations with the utmost accuracy prior to treatment.

Hearing Preservation Outcomes Following New Slim Lateral Wall Electrode Implantation

Natalie M. Schauwecker, MD (Presenter); Ankita Patro, MD; Robert Labadie; Alejandro Rivas; David S. Haynes, MD, MMHC; Elizabeth L. Perkins, MD

Introduction: In 2017 a thin, lateral wall electrode array (EA), the HiFocus SlimJ, was introduced by Advanced Bionics to promote hearing preservation (HP) in cochlear implantation (CI). This study reports hearing and speech outcomes with the Slim J at a high-volume CI, center and explores rates of implant failure and necessary revisions in the setting of malfunction from recent EA anomalies.

Method: A retrospective chart review was conducted to identify adults implanted with the HiFocus SlimJ EA between 2017 and 2020. Candidates who met HP criteria had a low-frequency pure-tone average (LFPTA) less than 80 dB at 125, 250, and 500 Hz preimplantation. Demographic variables as well as pre- and postoperative audiometric and speech performance outcomes were collected. Implants concerning for failure underwent integrity testing.

Results: A total of 65 implanted patients met criteria for HP, with an average LFPTA of 55.6 (range 15.0–80.0). At activation, 33 (50.8%) patients had HP and a mean LFPTA shift of 14.6 dB (range −28 to 62). Of those who met hybrid criteria preoperatively (n = 45, LFPTA less than 65 dB), 34 (75.6%) patients had hearing preserved at activation. CNC scores improved significantly from 21% (range 0%–60%, P < .0001) preoperatively to a mean of 45% (range 0%–86%, P < .0001) at 6 months and 52% (range, 0%–92%, P < .0001) at 12 months. A total of 5 (7.7%) patients underwent revision surgery due to poor performance and failure confirmed with integrity testing.

Conclusion: The HiFocus SlimJ EA is a slim, lateral wall electrode that offers successful hearing preservation. Thus far, a small proportion of patients in this cohort have undergone revision due to implant failure. We aim to report long-term HP rates and further monitor device failures.

Impact of Comorbid Conditions on Surgical Complications Following Mastoidectomy

Sudeepti Vedula (Presenter); Dhvani Shihora; Stefanie Legalia; Christina H. Fang, MD; Robert Jyung, MD; Jean Anderson Eloy, MD

Introduction: Comorbid conditions have been shown to be linked to poorer surgical outcomes in otolaryngology. The goal of this study is to examine the association between comorbid conditions and postoperative complications following mastoidectomy.

Method: The National Surgical Quality Improvement Program was queried for all mastoidectomy procedures performed between 2005 and 2016. Univariate and multivariate logistic regression were performed to determine the association between comorbidities and postsurgical complications of mastoidectomy.

Results: A total of 5492 cases of mastoidectomy were identified. Most patients were between the ages of 41 and 60 years (37.7%), male (52.7%), and White (63.1%). The most common comorbid conditions of these patients were metabolic syndrome (4.7%), dyspnea (2.8%), and chronic obstructive pulmonary disease (COPD; 2.4%). Patients with these comorbidities had a higher incidence of overall surgical complications (odds ratio [OR] 2.685; 95% CI, 2.679–2.691; P < .001), and medical complications (OR 1.260; 95% CI, 1.258–1.261; P = .029). However, the presence of these comorbidities did not have a significant association with length of hospital stay.

Conclusion: In patients who underwent mastoidectomy, metabolic syndrome, COPD, and dyspnea use were associated with an increased incidence of surgical and medical complications. These comorbidities should be considered when educating patients on the risk of postoperative complications following mastoidectomy.

Impact of Race on Cochlear Implant Access and Utilization

Geethanjeli N. Mahendran (Presenter); Tyler Rosenbluth; Candace E. Hobson, MD

Introduction: Cochlear implant (CI) utilization rates for American adults are estimated at 6% to 10%. While multiple factors contribute to this low rate, there are limited published data investigating racial and socioeconomic disparities in adult CI. In this study, we aim to compare rates of CI, referral and CI, across patients of different racial and socioeconomic backgrounds and to compare audiometric profiles of these patients.

Method: This is a retrospective review of adult patients who underwent CI, evaluation (CIE) or cochlear implantation at a tertiary care institution from 2010 to 2020.

Results: A total of 504 patients underwent CIE; 388 met CI, eligibility criteria and 269 underwent cochlear implantation. The racial breakdown of patients who underwent CIE was 68.5% White, 18.5% African American (AA), and 12.3% Asian. In contrast, Atlanta is 40.9% White, 51% AA, and 4.4% Asian (P < .001); Georgia is 60.2% White, 32.6% AA, and 4.4% Asian (P < .001). AAs referred for CIE had significantly worse hearing (mean pure-tone average [PTA] 92 dB, 13.9% word recognition score [WRS]) than White (mean PTA 85.8 dB, P = .003; 24.2% WRS, P = .01) and Asian patients (mean PTA 85.1 dB, P = .02; 27.1% WRS, P = .02). AAs undergoing CIE also had significantly worse AzBios scores than Whites and Asians did: AzBios worse-hearing ear 7.96% for AAs, 18.3% for Whites (P = .001), and 20.4% for Asians (P = .001). There was no significant difference in cochlear implantation rates between eligible AA and White patients; however, CI-eligible Asians were significantly less likely to undergo implantation than White patients were (P < .001). There were no significant differences in the breakdown of public vs private insurance across races, but it is worth noting that Medicaid does not cover adult CI, in the state in which this study was conducted.

Conclusion: AAs undergo CIE and cochlear implantation at rates disproportionately lower than expected based on local demographics. In addition, AAs have significantly worse hearing at the time of CI, referral than White and Asian patients do. Identifying and increasing awareness of these disparities are essential steps to improving CI, access for potentially disadvantaged populations.

In-Office Bone Anchored Hearing Implants in a Veteran Population

Lane D. Squires, MD (Presenter); Jackson King

Introduction: The minimally invasive punch technique for bone anchored implantation has not been studied in a veteran population to date. Offering an in-office surgical option for veterans at the VA follows the nationwide trend toward moving more procedural care out of overloaded operating rooms and improved cost savings. We examine the safety, feasibility, and outcomes of our case series of veterans with bone anchored hearing implantation under local anesthetic in an office-setting.

Method: In this study, we analyze a case series of minimally invasive ponto surgeries (MIPS) accomplished under local anesthetic in an VA clinic setting spanning a 2-year period from 2018 to 2020. Safety and feasibility data are presented, as well as major and minor complication rates. These outcomes are compared with historical reports. Patient-reported tolerability of procedure is surveyed.

Results: A total of 20 MIPS procedures were performed on veterans under local anesthetic in the office setting. Mean follow-up for patients was 17.1 months. No major complications were reported. Minor complications were not significantly different from historical reported data on bone anchored hearing implantation. No procedures were aborted, and all veterans tolerated procedures well by surveyed responses. SSQ-8 survey data collected show an overwhelmingly positive experience for implanted veterans.

Conclusion: This is the first reported series of MIPS to be done under local anesthesia in a VA clinic setting. Herein, we show patient tolerability, safety, and consistently excellent outcomes without major complications. We urge consideration of this procedural approach to be more widespread in a veteran population.

Laminin-Induced Schwann Cell Migration and Neuronal Growth of Spiral Ganglia

Carly Misztal (Presenter); Stefania Goncalves, MD; Olena Bracho; Christine T. Dinh, MD

Introduction: Growth of spiral ganglion neurons toward electrode contacts may improve hearing outcomes after cochlear implant (CI) surgery. Laminin is an extracellular matrix protein that can bind to B1-integrin receptors and promote Schwann cell migration and survival, which provide physical scaffolds and trophic support for neurites to grow. In this study, we investigate how laminin affects Schwann cell migration and neuronal axon extension in spiral ganglion cultures in vitro to explore the potential benefit of laminin-coated electrodes.

Method: Spiral ganglia were harvested and cultured from neonatal rats. Migration assays were created by culturing spiral ganglia against low- (5 µg/mL) or high-dose (1.2 mg/mL) laminin in a 2-well insert dishes. After insert removal, cells were treated with B1-integrin antibody (0 or 1 µg/mL) for up to 96 hours. Immunostaining for Tuj1 (neuronal cell marker) and S100 (Schwann cell marker) was performed at 0 and 96 hours. Confocal microscopy was used to visualize neurite outgrowth and Schwann cell migration. Images were measured with ImageJ software.

Results: Schwann cell migration and neurite outgrowth toward laminin-coated wells were observed in both low- and high-dose laminin conditions. Treatment with B1-integrin antibody decreased Schwann cell migration and neurite outgrowth toward laminin-coated wells, suggesting that Schwann cell migration is dependent on laminin activation of B1-integrin receptor. Furthermore, spiral ganglion cultures required high-dose laminin to induce cell aggregation into neuronal ganglia with radially projecting axonal tracts, which may be beneficial for signal transduction after cochlear implantation.

Conclusion: Laminin induces Schwann cell migration through activation of B1-integrin receptors, which in turn initiates neurite outgrowth from spiral ganglia cultures. These findings suggest that laminin coating may promote Schwann cell migration and neurite growth toward CI, electrodes, which can potentially improve hearing outcomes after CI, surgery.

Phase 1/2 Study of Neurotrophin OTO-413 for Hearing Loss

Peter G. Volsky, MD (Presenter); James M. Robinson; Alice Blaj, PharmD; David Moore, PhD; Victoria Sanchez, AuD, PhD; Jeffery J. Anderson, PhD

Introduction: Research shows that cochlear synaptopathy plays a role in hearing loss. Treatment with brain-derived neurotrophic factor (BDNF) repairs synaptic processes and restores hearing function in animal models. OTO-413, a sustained-exposure formulation of BDNF for intratympanic (IT) administration, is under evaluation for the treatment of hearing loss.

Method: This was a randomized, double-blind, placebo-controlled phase 1/2 study. Men and women aged 21 to 64 years were enrolled between December 2019 and August 2020. Pure-tone thresholds ranged from normal levels to moderately severe hearing loss (pure-tone average of ≤70 dB at 1, 2, and 4 kHz). Self-reported difficulty hearing in noise was confirmed by digits-in-noise (DIN) test scores greater than −12.5 dB signal-to-noise ratio (SNR) in the study ear. Four ascending dose cohorts of at least 8 subjects, each received a single IT injection of OTO-413 or placebo. Safety and hearing function were monitored over a 12-week follow-up. Hearing assessments included DIN, words-in-noise (WIN) test, and American English matrix test (AEMT).

Results: OTO-413 was well-tolerated across all dose cohorts (n = 29) with a similar frequency of adverse events compared with placebo (n = 10). There were no serious adverse events. Six of 9 (67%) subjects treated with the highest dose of OTO-413 (0.30 mg) showed a clinically meaningful improvement on at least 1 of the 3 speech-in-noise tests at both day 57 and 85 vs 0 of 8 (0%) for placebo. A clinically meaningful improvement was defined as a minimum change of −3 dB SNR (DIN) or −2 dB SNR (WIN and AEMT). Performance on the sentence-based AEMT favored OTO-413, with 4 of 9 (44%) OTO-413 subjects experiencing a clinically meaningful improvement at both day 57 and 85 compared with 0 of 7 (0%) placebo subjects at any single time point. Statistical analysis was not performed because of the small samples.

Conclusion: These results demonstrate the safety of OTO-413 and suggest therapeutic benefit over placebo in a small sample size. These findings support further clinical development of OTO-413 for the treatment of hearing loss.

Predicting CSF Leak After Posterior Fossa Surgery

Michael H. Freeman (Presenter); Nathan Cass; Elizabeth L. Perkins, MD; Nauman Manzoor; Kareem Tawfik; Marc L. Bennett, MD

Introduction: This work seeks to establish expected rates of postoperative cerebrospinal fluid (CSF) leak after translabyrinthine (TL) and retrosigmoid (RS) surgery for posterior fossa tumor resection and to determine the impact of preoperative risk factors on postoperative CSF leak rates.

Method: A retrospective case series analysis was conducted with postoperative CSF leak as the primary outcome measure. All TL or RS cases at a single tertiary referral center over 10 years were included in the analysis.

Results: A total of 437 patients underwent TL (n = 326) or RS (n = 111) approaches for posterior fossa tumors. Median age was 51.5 years, median body mass index (BMI) was 28.3, and mean tumor length in maximal dimension was 2.67 cm. CSF leak occurred in 16.4% of cases but was more likely in obese patients (21.5%) than in nonobese patients (11.7%). Lumbar drains were the most frequent management strategy (62.5% of leaks), with 30.5% of leaks ultimately requiring VP shunt placement. Multivariate logistic regression comparing age, sex, ethnicity, tumor laterality, diabetes, hypertension, tumor size (4 cm), and obesity (BMI >30) demonstrated a statistically significant relationship between obesity and postoperative CSF leak (odds ratio = 1.82) with no other variables approaching significance. Linear regression analysis demonstrated increased CSF leak rate with increasing tumor length (P < .05).

Conclusion: Obesity appears to significantly increase the risk of postoperative CSF leak. Increasing tumor length in the maximal dimension also appears to increase CSF leak risk.

Progression of Hearing Loss in Observed Non-growing Vestibular Schwannoma

Alexander L. Luryi, MD (Presenter); Seilesh C. Babu, MD; Dennis Bojrab; John Kveton; Elias Michaelides; Christopher A. Schutt, MD

Introduction: Vestibular schwannoma treated with observation may lead to accelerated hearing loss even without tumor growth. This study aims to assess hearing outcomes in observed vestibular schwannoma (VS) with focus on non-growing tumors.

Method: This was a retrospective review of patients with sporadic VS undergoing at least 3 years’ observation as initial management at 2 tertiary neurotology centers from 2007 to 2017. Main outcome measures were overall and yearly changes in pure-tone averages (PTAs) and word recognition scores (WRS) normalized to corresponding changes in the contralateral ear.

Results: During the study period, 39 of 105 included patients (37.1%) had tumor growth and 66 (62.9%) did not. Patients with tumor growth had a mean normalized increase in PTA of 8.0 dB HL (P = .008) relative to the contralateral ear, corresponding to a normalized average worsening of their PTA of 1.8 dB per year. Patients with non-growing tumors <5 mm in maximal dimension did not have significant ongoing hearing loss compared to the contralateral ear (P > .05). Patients with non-growing tumors ≥5 mm in the maximal dimension had a mean increase in PTA of 7.4 dB HL (P = .001) relative to the contralateral ear, corresponding to an average of 2.0 dB HL per year, which was statistically similar to the loss observed in growing tumors regardless of size (P > .05). A normalized decline in PTA of at least 5 dB HL was seen in 72% of patients with growing tumors, 53% of patients with non-growing tumors ≥5 mm, and 38% of patients with non-growing tumors <5 mm.

Conclusion: A long-term analysis of hearing outcomes in observed vestibular schwannoma is presented. With observation, VS greater than 5 mm is associated with continued hearing loss even without tumor growth, while non-growing tumors less than 5 mm are not associated with continuing hearing loss. These data inform expectations for observed VS for both providers and patients.

Prolonged Duration of Deafness in Single-Sided Deafness Cochlear Implantation

Ashley M. Nassiri, MD, MBA (Presenter); Katherine P. Wallerius, MD; Aniket A. Saoji, PhD; Brian A. Neff, MD; Colin L. Driscoll, MD; Matthew L. Carlson, MD

Introduction: Prolonged duration of deafness is often considered a strong negative prognostic factor in speech perception outcomes for traditional bilateral hearing loss cochlear implant (CI) recipients; however, the association of this feature in CI, recipients with single-sided deafness (SSD) is not yet well characterized.

Method: SSD was defined as a pure-tone average (PTA) >70 dB with normal hearing in the contralateral ear (10 years) and the remaining referent cohort.

Results: Seven SSD patients with prolonged duration of deafness (mean 22 years, SD 12) were compared with 28 SSD referent patients with duration of deafness less than 10 years (mean 2.4 years, SD 2). The average follow-up duration was 10 months (SD 7 months). At last follow-up, the average consonant-nucleus-consonant (CNC) scores were 48% (SD 24, range 26–84) and 54% (SD 15, range 10–78) for the prolonged duration of deafness and referent cohorts, respectively (P = .3). The average AzBio in quiet scores was 69% (SD 12, range 64–93) and 69% (SD 18, range 24–97) for the prolonged duration of deafness and referent cohorts, respectively (P = .6). In a separate analysis evaluating the duration of deafness as a continuous variable across both cohorts, Spearman correlation coefficients for associations of duration of deafness with most recent CNC and AzBio scores were −0.02 (P = .92) and 0.02 (P = .93), respectively.

Conclusion: These data suggest that duration of deafness is not strongly associated with speech perception outcomes in SSD CI, recipients. Consequently, prolonged duration of deafness alone should not preclude CI, in SSD patients.

RAD51 Inhibitor and Radiation Toxicity in Vestibular Schwannoma Cells

Torin P. Thielhelm (Presenter); Scott Welford, PhD; Eric A. Mellon, MD, PhD; Fred Telischi, MD; Michael E. Ivan, MD; Christine T. Dinh, MD

Introduction: Ionizing radiation can initiate the formation of double-stranded breaks (DSBs) in DNA that activate cell death pathways. Tumors can evade radiation-induced cell death by upregulating cell-cycle arrest and DNA repair proteins. In this study, we describe upregulation of the DNA repair protein RAD51 in response to radiation-induced DSBs in vestibular schwannoma (VS) and investigate the utility of RAD51 inhibitor, RI-1, in enhancing radiation toxicity.

Method: To identify therapeutic targets, we used high-throughput antibody arrays to quantify the expression of 60 cell-cycle proteins on radiation-resistant VS and age-matched nonirradiated controls. To analyze whether RAD51 inhibition can enhance radiation toxicity, primary VS cells were cultured on 96-well plates and 16-well slides, exposed to radiation (0, 6, 12, or 18 Gy) and treated with RI-1 (0 or 5 µM). Immunofluorescence was performed at 6 hours for H2AX (DSB marker), RAD51 (DNA repair protein), and p21 (cell-cycle arrest protein). Viability assays were performed at 96 hours. Data were analyzed with 2-way analysis of variance with post hoc testing.

Results: Microarray analysis suggests that VS may resist radiation by upregulating RAD51 DNA repair. In addition, primary VS cells demonstrated increases in RAD51 (DNA repair), in response to radiation-induced expression of H2AX (DNA damage). Irradiated VS cells also demonstrated upregulation in p21, suggesting that VS cells enter cell-cycle arrest to repair injured DNA. Addition of RI-1 reduced the expression of RAD51, resulting in increased H2AX expression and reduced viability in some VS.

Conclusion: VS may evade radiation injury by entering cell-cycle arrest and upregulating RAD51-dependent repair of radiation-induced DSBs in DNA. Although there is heterogeneity in responses among individual VS, RI-1 can reduce RAD51-dependent DNA repair to enhance radiation toxicity in VS cells. Further investigations are warranted to understand the mechanisms of radiation resistance in VS and determine whether RI-1 is an effective radiosensitizer in VS patients.

Revision Stapes Surgery: Hearing Symptoms and Associations With Intra-operative Findings

Alexander L. Luryi, MD (Presenter); Amy Schettino; Elias Michaelides; Seilesh C. Babu, MD; Dennis Bojrab; Christopher A. Schutt, MD

Introduction: Stapes surgery for otosclerosis sometimes requires revision due to recurrent or persistent conductive hearing loss (CHL). This study aims to examine the associations between hearing symptoms and intraoperative findings as well as outcomes after revision stapes surgery.

Method: Patients treated with revision stapes surgery for otosclerosis from 2008 and 2017 at a tertiary otology referral center were reviewed retrospectively. Primary outcome measures were postoperative air–bone gap (ABG), air conduction (AC), and bone conduction (BC) pure-tone averages (PTAs).

Results: During the study period, 120 patients underwent revision stapes surgery. Some 88 patients (73%) had a gradually progressive recurrent CHL, 11 (9%) had sudden recurrent CHL, 11 (9%) had persistent CHL despite prior surgery, and 10 (8%) had no CHL and underwent revision surgery for other reasons. Of 110 patients with CHL, the most common intraoperative findings were prosthesis displacement with (42%) or without (41%) incus necrosis, normal anatomy with good prosthesis placement (7 patients, 6%), and abundant scar tissue (6 patients, 6%). AC thresholds and ABGs in these patients improved from averages of 56.9 and 24.3 dB to 38.6 dB (P = .05). In total, 3 patients (2.5%) developed sensorineural hearing loss with an increase of BC PTA of at least 15 dB HL, all of whom had a gradual recurrent CHL (P > .05). There were no cases of facial weakness, reparative granuloma, or procedure abortion.

Conclusion: Revision stapes surgery is safe and confers significant hearing improvement in patients with both persistent and recurrent CHL, although patients with persistent CHL see less improvement with revision.

Revisiting the Paradigm on Hearing Preservation in Medium-to-Large Vestibular Schwannoma

Robert J. Macielak, MD (Presenter); Katherine P. Wallerius, MD; Skye K. Lawlor, MD; Christine M. Lohse, MS; Matthew L. Carlson, MD

Introduction: Prior studies have reasoned against attempts to preserve functional hearing in medium-to-large vestibular schwannoma (VS) in which hearing preservation is less likely, instead proceeding with a translabyrinthine approach. In light of more recent quality-of-life data indicating minimal differences among surgical approaches and a paradigm considering cochlear implantation (CI) in this population, we sought to review hearing preservation results in a large cohort including patients with tumors ≥15 mm in maximum cerebellopontine angle (CPA) dimension.

Method: A consecutive series of patients with VS who underwent microsurgery between January 2000 and May 2020 was identified. Baseline, intraoperative, and postoperative patient and tumor characteristics were collected. Serviceable hearing was defined by a pure-tone average 50%.

Results: A total of 243 patients had serviceable hearing preoperatively and sufficient postoperative data for study inclusion. Of these tumors, 50 (21%) were confined to the internal auditory canal (IAC), and the median tumor size was 16.2 mm (interquartile range [IQR] 11.3–23.2) for tumors with a CPA component. For all tumors, the median fundal fluid cap was 2.3 mm (IQR 0.0–4.7). A retrosigmoid approach was used in 223 (92%) cases and a middle cranial fossa approach was used in 20 (8%). There was an inverse relationship between tumor size and probability of successful hearing preservation (P < .001). The rate of serviceable hearing preservation in patients with tumors in the IAC, CPA <15 mm, and CPA ≥15 mm was 32 (64%), 24 (28%), and 10 (9%), respectively.

Conclusion: Functional hearing preservation in VS with ≥15-mm CPA extension is possible in approximately 10% of cases. Furthermore, hearing preservation microsurgery offers anatomical cochlear nerve preservation and cochlear patency in many cases, allowing for possible future CI. These findings challenge the notion of favoring translabyrinthine surgery for patients with medium-to-large sized tumors when preoperative serviceable hearing is present.

Salvage Following Failed Primary Treatment of Vestibular Schwannomas

Emily Kay-Rivest, MD, MSc, FRCSC (Presenter); Douglas Kondziolka; John Golfinos; Sean McMenomey; David Friedmann; J. Thomas Roland Jr

Introduction: The objective of this study was to evaluate patient outcomes following salvage microsurgical resection (MS) and salvage stereotactic radiosurgery (SRS) after failure of primary treatment with either modality for vestibular schwannomas (VS).

Method: A retrospective chart review of patients with more than 1 intervention for their VS was performed. Clinical, radiological, surgical, and radiosurgical data were collected. Patients were divided into 4 groups: SRS followed by SRS (n = 7), MS followed by SRS (n = 61), SRS followed by MS (n = 6), and MS followed by MS (n = 9), and outcomes were evaluated.

Results: A total of 83 patients were included. Patients who underwent SRS first were on average older at the time of diagnosis and had smaller tumors. For the SRS followed by SRS group, the mean interval between treatments was 53 months, no patient developed facial weakness, and 14% (1 patient) developed new trigeminal sensory loss. In the MS followed by SRS group, 3% (2 patients) developed facial weakness following SRS. In this same group, 7% (4 patients) developed trigeminal nerve deficits and 7% developed facial spasms. In the SRS followed by MS group, 2 of 6 patients developed worse facial function after salvage MS. Finally, in the MS then MS group, 1 patient had a complete facial paralysis postoperatively while the remaining patients (n = 6) had House-Brackmann (HB) scores of 2 or 3. Within this same group, we compared the use of a different surgical approach to the same approach. Gross-total resection occurred more commonly when a different approach was used, although not statistically significant (P = .29) and facial nerve outcomes were similar (P = .86). Cerebrospinal fluid leaks occurred more frequently when using the same approach, although the difference was not statistically significant (P = .15). In our total cohort, 6 patients (7%) required a third treatment after their original salvage.

Conclusion: Salvage SRS carries low rates of facial nerve dysfunction, even following previous SRS. Salvage MS has poorer facial nerve outcomes, although HB scores greater than 3 are achievable, and selecting an alternative approach may result in better outcomes.

A Second Independent Phase 1b Demonstrates Hearing Improvement With FX-322

John Ansley, MD (Presenter); Carl LeBel, MD; Susan King, MD; Sam Wilson, MD; Christopher Loose, MD; Will J. McLean, MD

Introduction: FX-322, a small-molecule combination designed to regenerate hair cells, demonstrated an increase in word recognition (WR) and words-in-noise (WIN) testing in a double-blind, placebo-controlled study of 23 subjects with permanent sudden sensorineural hearing loss (SSNHL) or noise-induced hearing loss (NIHL) (presented at the American Academy of Otolaryngology [AAO] 2019). Further, the effect was durable for 13 to 21 months (presented at the AAO, 2020). A second single-dose study recently has been completed to assess 2 different formulation preparations in subjects with permanent SSNHL, NIHL, or idiopathic SNHL.The abstract describes an outcome of the clinical study that became available only after the original abstract deadline and could not be completed prior to the deadline. These results have not been presented, accepted for presentation, or published at any other scientific meeting or journal.

Methods: A total of 33 subjects with permanent SNNHL, NIHLm or idiopathic SNHL were dosed unilaterally in an open-label study with the contralateral ear serving as a control. All protocols were approved by the Institutional Review Board, and subjects were consented for multiple clinic visits out to 90 days for otoscopy, pure-tone audiometry, speech intelligibility, and adverse events.

Results: Of the 33 dosed subjects, 6 showed statistically significant improvements in WR, exceeding the 95% confidence intervals defined in Thornton and Raffin (1978). In addition, 34% of FX-322 treated subjects showed WR increases of at least 10% (absolute). In contrast, no significant changes were seen in untreated contralateral ears. Consistent with the previous study, WR improvements primarily occurred in ears that started with a greater WR deficit. Pooled data and analysis across multiple FX-322 trials to date will also be presented.

Conclusion: This work demonstrates that in a second independent single-dose study FX-322 is associated with statistically significant improvements in WR and supports the continued evaluation in multiple populations to determine the ranges of SNHL that FX-322 might address as an ear, nose, and throat (ENT)-administered therapeutic for hearing restoration.

Sigmoid Sinus Thrombosis After Translabyrinthine Surgery

Nathan Cass, MD (Presenter); Michael H. Freeman; Elizabeth L. Perkins, MD; Nauman Manzoor; Matthew O’Malley; David S. Haynes, MD, MMHC

Introduction: Changes to dural venous flow may alter intracranial pressures and translabyrinthine (TL) surgery involves manipulation of the sigmoid sinus. We sought to characterize the incidence of sigmoid sinus thrombosis after TL surgery for posterior fossa tumor resection, and determine association with postoperative cerebrospinal fluid (CSF) leak, hydrocephalus, or need for long-term CSF diversion.

Method: We performed a retrospective chart review of all patients undergoing TL surgery for posterior fossa tumor over a 10-year period at a single tertiary referral center, evaluating for incidence of immediate postoperative sigmoid sinus thrombosis as well as postoperative CSF leak, hydrocephalus, and shunt placement.

Results: A total of 326 patients with posterior fossa tumors underwent TL excision over a 10-year period. Median age was 50 years and mean tumor length 2.58 cm. The incidence of postoperative sigmoid sinus thrombosis on magnetic resonance imaging was 14.4%. One patient was noted to have additional transverse sinus thrombosis and placed on warfarin. CSF leaks were no more likely to occur in those with thrombosis (12.8%) compared with those without thrombosis (15.4%). No patients with sigmoid sinus thrombosis developed hydrocephalus or required a shunt. However, 24.5% of patients with CSF leaks and 75% of those with postoperative hydrocephalus eventually underwent shunting.

Conclusion: Sigmoid sinus thrombosis occurs frequently after TL surgery but is not associated with an increased incidence of CSF leak, hydrocephalus, or need for long-term CSF diversion. Systemic anticoagulation, as suggested by some groups, appears to be unnecessary for preventing complications of isolated sigmoid sinus thrombosis.

Skull Vibration Induced Nystagmus Test, Otolith and Canal Vestibular Function

Sebastien Schmerber, MD, PhD (Presenter); Christol Fabre; Ludovic Giraud; Philippe Perrin; Georges Dumas

Introduction: We aim to establish in unilateral peripheral vestibular lesions (UVL) patients a relationship between skull vibration induced nystagmus (SVIN) different components (horizontal, vertical, torsional) and the results of different structurally related vestibular tests.

Method: This is a retrospective cohort study. SVIN test, canal vestibular test (CVT; caloric test + video head impulse test [VHIT]), otolithic vestibular test (OVT; ocular vestibular evoked myogenic potential [oVEMP] + cervical vestibular evoked myogenic potential [cVEMP]) were performed on the same day in 63 patients with UVL (age <65 years) and 10 normal subjects. This population was divided as follows: group-Co (control group), group-VNT (dizzy patients with no OVT or CVT alterations), group-O (OVT alterations only), group-C (CVT alterations only), group-M (mixed alterations). SVIN slow-phase velocity (SPV) was analyzed by groups and compared with vestibular tests results.

Results: The SVIN-SPV horizontal component was significantly higher in group-M than in the other groups (P = .005) and correlated with alterations of lateral-VHIT (P < .001), caloric test (P = .002), and oVEMP (P = .006). SVIN-SPV vertical component was correlated with the anterior-VHIT and oVEMP alterations (P = .007 and P = .017, respectively). SVIN-SPV torsional component was correlated with the anterior-VHIT positivity (P = .017). In 10% of patients of the group-VNT, SVIN was the only positive test.

Conclusion: SVIN-SPV is significantly higher in patients with combined canal and otolith lesions. SVIN-SPV analysis in UVL shows significant correlation with T hypofunction, jorizontal VHIT gain asymmetry, and oVEMP results suggesting a strong contribution of the horizontal caqnal and at a lesser degree of the utricle. SVIN reflects primarily alterations in the VIIIth nerve superior root territory. SVIN is sometimes the only positive test in rare patients with unexplained dizziness.

Superior Semicircular Canal Dehiscence Impact on Cochlear Implant Audiologic Outcomes

William G. Kady, DO (Presenter); Nathan C. Tu, MD; Kenny Lin; Pedrom C. Sioshansi, MD; Dennis Bojrab II, MD; Seilesh C. Babu, MD

Introduction: We aim to determine whether adult cochlear implant (CI) users with superior semicircular canal dehiscence or near dehiscence experience clinically significant differences in audiological outcomes when compared with CI, users with normal temporal bone anatomy.

Method: This is a retrospective review of CI, users with radiographically confirmed superior semicircular canal complete dehiscence or near dehiscence. Study participants had cochlear implantation between 2010 and 2020. Fifteen individuals were identified to have complete superior canal dehiscence, 28 individuals with near dehiscence, and 67 controls with normal temporal bone anatomy. The primary audiologic outcome analyzed was preoperative and postoperative AzBio scores, change in AzBio scores, and presence or absence of superior semicircular canal dehiscence (SSCD) on imaging. A secondary outcome measure was the duration of deafness prior to implantation, defined as the length of time with minimal usable hearing as reported to the audiology team by the patient/family.

Results: A total of 938 patients underwent cochlear implantation with 110 patients having met inclusion criteria. The mean AzBio score for the normal temporal bone anatomy group improved from 35.2% (SD 28.2) preoperatively to 70.3% (SD 25.7) postoperatively, an improvement of 35.1% (SD 28.6). The mean AzBio score for the near dehiscent temporal bone anatomy group improved from 26.6% (SD 28.9) preoperatively to 64.5% (SD 30.6) postoperatively, an improvement of 37.9% (SD 27.9). The mean AzBio score for the dehiscent temporal bone anatomy group improved from 26.3% (SD 20.4) preoperatively to 65.1% (SD 27.6) postoperatively, an improvement of 38.7% (SD 26.9). Using the 1-way analysis of variance, no statistically significant difference in audiologic outcomes exists between the 3 groups.

Conclusion: Patients with complete or near-complete radiographic superior canal dehiscence at the time of CI, surgery have similar speech perception scores compared with non-SSCD adult CI, users.

Temporal Bone Resection for Skull Base Malignancy: Review and Analysis

Matthew McCracken, MS (Presenter); Kavya Pai; Claudia I. Cabrera, MD, MS; Benjamin Johnson, MD; Akina Tamaki, MD; Nauman Manzoor, MD

Introduction: Malignancies involving the temporal bone (TBM) are rare and often confer a poor prognosis due to advanced stage. Curative management involves surgical resection, but outcomes are varied in the literature due to heterogeneous pathology and smaller institutional cohorts. The aim of this study is to provide a synthesis of survival and recurrence outcomes data reported in the literature for patients that underwent temporal bone resection (TBR).

Method: A systematic review was conducted in December 2020 according to the PRISMA 2009 guidelines. We included titles that reported survival and/or recurrence rates after lateral or extended (subtotal, total) TBR for curative treatment of TBM. Patients with melanoma, parotid malignancies, and other rare tumors were excluded. Patients with squamous cell carcinoma and complete data on time to event, vital status, Pittsburgh stage, and type of surgical resection were included in the final Cox proportional hazards regression model.

Results: Survival data were collected from 27 retrospectives studies, resulting in a pooled cohort of 307 patients with a mean follow-up time of 51.6 months. Recurrence rates for patients with early stage disease (stages 1 and 2) and advanced-stage (stages 3 and 4) were 19% and 54%, respectively. The adjusted Cox regression adjusted by stage and resection type revealed an increased risk of death for stage 3 and 4 disease (hazard ratio [HR] 3.16 [95% CI, 1.48, 6.74], P < .01, and 5.71 [2.75, 11.9], P < .01), respectively. However, there was no difference in the risk of death by resection type.

Conclusion: Advanced-stage malignancies involving the temporal bone portend poor overall survival compared with early stage disease. It is plausible that unstudied factors such as nodal disease and use of adjuvant radiation influence these outcomes. Larger prospective multi-institutional studies are needed to ascertain prognostic factors for survival and recurrence.

Treatment of Tinnitus With Sound Conditioning Therapy

Angela Ronderos, MD (Presenter); Alejandro Garcia, MD; Daniela Gonzalez, MD; Clemencia Baron, AuD; Juan Manuel Garcia, MD

Introduction : The efficacy of sound-conditioning therapy (SCT) in the treatment of tinnitus has not been widely established; however, patients report a subjective benefit attributed to therapeutic frequency-modulated noise. This is explained by a central auditory system hyperactivity that counteracts the maladaptive mechanism of tinnitus. The general objective of this study is to evaluate in patient with tinnitus who have normal and mild to moderate hearing loss the use of SCT combined with counseling in a tinnitus clinic at Bogotá, Colombia.

Method: A retrospective observational study was conducted evaluating 18 patients treated with SCT in our hospital between 2018 and 2020. Demographic variables, classification, and degree of hearing loss and tinnitus were evaluated. The intensity of tinnitus was quantified in dB sensation level (SL) and measured with the visual analog scale (VAS). Quality of life was evaluated with the Tinnitus Handicap Inventory (THI) and Tinnitus Reaction Questionnaire (TRQ). For statistical analysis a paired t test was used for parametric data and a Wilcoxon signed-rank test for nonparametric data.

Results: Patients received SCT for 4 to 6 months with 2 daily customized sound sessions and periodic counseling based on cognitive behavioral therapy (CBT) principles. After treatment, there was a significant decrease (P < .01) for all outcomes measured including a mean difference in tinnitus intensity of 7.6 dB (4.59–10.75; 95% CI), VAS score of 4.5 (3.54–5.57; 95% CI), TRQ score of 36.44 (29.83–43.06; 95% CI) and THI score of 33.1 (25.65–40.57; 95% CI) compared with baseline.

Conclusion: SCT should be available as an alternative in patients with tinnitus treated by a multidisciplinary team. This study shows the improvement in symptoms and quality of life after treatment with SCT combined with counseling. Further studies can be conducted with a larger sample size and longer follow-up periods to show the overall effect of SCT.

Use of Telemedicine in an Otology Outpatient Clinic During COVID-19

Franklin M. Wu (Presenter); Ruben Ulloa; Carlos Stellanos, MHS; Janet S. Choi, MD; Courtney Voelker, MD, PhD

Introduction: This study aims to explore the role of telemedicine in an otology outpatient clinic during the COVID-19 pandemic. We investigated the pattern of follow-up after initial telemedicine visits and concordance rate between the diagnoses from the initial telemedicine visit and in-person follow-up visit.

Method: All new patients who had telemedicine encounters with 3 providers at a tertiary care center otology outpatient clinic between April and October 2020 were included. Retrospective chart review was performed to collect patient demographics, clinical information, and follow-up plans. Primary outcomes included whether the patients needed an in-person or telemedicine follow-up and diagnostic concordance between the initial telemedicine and follow-up in-person encounters. Multivariate logistic regression analyses were conducted to assess associated factors.

Results: A total of 348 new patients were seen for a telemedicine visit during the study period. Of these patients, 136 (39.1%) had an in-person follow-up visit and 46 (13.2%) had a telemedicine follow-up appointment. Multivariate regression models revealed that the chief complaint category was not significantly associated with in-person follow-up visit status. Hispanics were less likely to have a follow-up visit compared with Whites (odds ratio: 0.27; 95% CI, 0.11, 0.64). The diagnostic concordance rate between the telemedicine visit and in-person visit with otoscopy was 75.7%. Demographic factors, chief complaint category, and visit time were not significantly associated with diagnostic concordance.

Conclusion: Many patients were able to have their needs met through an initial telemedicine visit in an otology outpatient setting during COVID-19. Diagnostic concordance between initial telemedicine and in-person follow-up visits was high. Although an in-person assessment is necessary for a full assessment of patients, telemedicine can be a useful tool for an initial evaluation of patients with otologic complaints during the COVID-19 pandemic.

Vestibular Dysfunction, Cognition, and Associated Sequela: Falls, Mobility, and Absenteeism

Thi A. Nguyen (Presenter); Jeffrey D. Sharon, MD

Introduction: Recent evidence has shown that vestibular vertigo is strongly associated with cognitive difficulties. We evaluated individuals with both vestibular vertigo and concomitant cognitive dysfunction to find whether there were associated effects on balance, mobility, and work ability.

Method: We performed multivariate analysis using data from the 2016 National Health Interview Survey (NHIS) of US adults. We evaluated whether individuals with both vestibular vertigo and cognitive dysfunction were more likely to suffer mobility and balance issues than individuals with either vestibular vertigo or cognitive impairment alone.

Results: Among individuals with vestibular vertigo, 34% have “some difficulty” thinking and 8% have “a lot of difficulty” thinking compared with 11% and 1% for those without vestibular vertigo, respectively. Those with a history of falls and vestibular vertigo had more than 4-fold increased odds of “difficulty remembering or concentrating” (odds ratio [OR] 4.48; 95% CI, 3.43 to 5.86) compared with individuals with either alone. Furthermore, individuals with both vestibular vertigo and cognitive dysfunction had more than 3-fold increased odds of falls (OR 3.25; 95% CI, 2.55 to 4.15), more than 8-fold odds of mobility issues (OR 8.52; 95% CI, 6.95 to 10.45), and more than 9-fold increased odds of missed workdays (OR 9.25; 95% CI, 3.21 to 15.28).

Conclusion: Our findings indicate that vestibular vertigo is not only associated with cognitive dysfunction, but vestibular vertigo and cognitive dysfunction together are associated with real-world consequences, including increased falls, decreased mobility, and increased work absenteeism.

Vestibular Imaging and Function in Congenital Inner Ear Malformations

Akinori Kashio, MD, PhD (Presenter); Alexander Dy, MD; Tsukasa Uranaka, MD; Hajime Koyama, MD; Chisato Fujimoto, MD, PhD; Tatsuya Yamasoba, MD, PhD

Introduction: In this study, we aim to investigate the association among cochlear anatomy, vestibular anatomy, and vestibular functions in children with profound sensorineural hearing loss.

Method: This is a retrospective study in an academic institution. A total of 41 pediatric patients with inner ear malformation (IEM) who had bilateral profound hearing loss and were candidates for cochlear implantation at the Tokyo University Hospital from January 1999 to October 2017 were reviewed. The type of cochlear malformation, the appearance of the semicircular canals (SCCs), and the volume of the vestibule were obtained from computed tomography imaging. To evaluate vestibular function, cervical vestibular evoked myogenic potential (VEMP) test, rotational chair test (RCT), and caloric test were conducted.

Results: Of 82 ears in 41 patients, the most frequent IEM was an incomplete partition (IP) II (29.3%) followed by isolated vestibular organ anomaly alone (20.7%) and IP I (18.3%). A total of 61 ears showed vestibular organ malformation. Of these, 48 ears had abnormal vestibule. Among 65 ears with various cochlear malformations, 39 (60%) had coexisting malformation in vestibule. common cavity (CC), IPI and cochlear hypoplasia (CH) IV had a high incidence of coexisting malformation of vestibule (100%, 93%, and 100%, respectively) whereas the incidence in IP I and IP III were low (17% and 0%, respectively). Some 58 ears (71%) showed abnormal VEMP. Abnormal vestibular volume was significantly associated with a nonreactive VEMP finding (χ²[4, N = 82] = 30.09, P < .001). Of 65 ears with vestibular organ malformation, 45 had abnormal lateral SCCs, and abnormal lateral SCCs were also associated with abnormal caloric and RTC results (P < .001).

Conclusion: Among patients with IEM, the second most frequent type was isolated vestibular organ anomaly without coexisting cochlear malformations. The co-incidence of malformation of vestibule in IP II and IP III were relatively low compared with CC, IP I, and CH IV. Abnormal vestibule volume was significantly associated with a nonreactive VEMP finding. Abnormalities in lateral SCC were also associated with abnormal caloric and RCT results.