Otology Neurotology

Book Review

01-03-2020 – Arriaga, Moises A.

No abstract available

Sex-based Differences in Hearing Loss: Perspectives From Non-clinical Research to Clinical Outcomess

01-03-2020 – Villavisanis, Dillan F.; Berson, Elisa R.; Lauer, Amanda M.; Cosetti, Maura K.; Schrode, Katrina M.

Journal Article

Introduction: It is estimated over 466 million people worldwide have disabling hearing loss, and untreated hearing loss is associated with poorer health outcomes. The influence of sex as a biological variable on hearing loss is not well understood, especially for differences in underlying mechanisms which are typically elucidated through non-clinical research. Although the inclusion of sex as a biological variable in clinical studies has been required since 1993, sex reporting has only been recently mandated in National Institutes of Health funded non-clinical studies.
Objective: This article reviews the literature on recent non-clinical and clinical research concerning sex-based differences in hearing loss primarily since 1993, and discusses implications for knowledge gaps in the translation from non-clinical to clinical realms.
Conclusions: The disparity between sex-based requirements for non-clinical versus clinical research may inhibit a comprehensive understanding of sex-based mechanistic differences. Such disparities may play a role in understanding and explaining clinically significant sex differences and are likely necessary for developing robust clinical treatment options.

A Systematic Review of Interventions for Balance Dysfunction in Patients With Vestibular Schwannoma

01-03-2020 – Ojha, Shilpa; Clamp, Philip J.

Journal Article

Objective: Dizziness is a major contributing factor to poor quality of life for patients with vestibular schwannoma (acoustic neuroma). We wished to review the literature on interventions for balance dysfunction in these patients.
Data Sources: A systematic literature review was performed identifying studies that measured balance function before and after treatment for vestibular schwannoma. Data sources include Medline (1950–present), EMBASE (1974–present), Cochrane Library (issue 3, 2008), NHS Centre of reviews and dissemination, Clinical Evidence, Cochrane central register of controlled trial, and CINAHL.
Study Selection: A minimum follow-up of 6 months was required, to estimate long-term balance function. Eight articles were identified, including five studies with surgical intervention, two studies with stereotactic radiotherapy, and one comparing the two. Study design was generally poor with a high risk of bias. These studies all utilized the Dizziness Handicap Inventory (DHI) as a measure of pre- and postintervention balance function.
Data Extraction: Results showed that overall DHI scores are not statistically affected by intervention irrespective of modality (surgery or stereotactic radiotherapy). Patients selected with severe dizziness, who undergo surgery, improved postoperatively. No other studies for severe dizziness were noted for comparison.
Conclusions: Age, sex, and tumor size have no statistically significant effect on DHI outcomes, and no evidence to suggest which treatment modality has better dizziness related outcomes.
No specific treatment modality was superior in terms of long-term balance function. Patients with severe dizziness may benefit from surgery, although no comparator studies were identified.

Reliability of Tablet-based Hearing Testing in Nicaraguan Schoolchildren: A Detailed Analysis

01-03-2020 – Magro, Isabelle; Clavier, Odile; Mojica, Karen; Rieke, Catherine; Eisen, Eric; Fried, Debra; Stein-Meyers, Anita; Fellows, Abigail; Buckey, Jay; Saunders, James

Journal Article

Objective: Determine whether an electronic tablet-based Wireless Automated Hearing-Test System can perform high-quality audiometry to assess schoolchildren for hearing loss in the field in Nicaragua.
Study Design: Cross-sectional.
Setting: A school and hospital-based audiology clinic in Jinotega, Nicaragua.
Subjects and Methods: Second and third graders (n = 120) were randomly selected for hearing testing in a school. Air conduction hearing thresholds were obtained bilaterally using a Wireless Automated Hearing-Test System at 1000, 2000, and 4000 Hz. Referral criteria were set at more than 25 d
BHL at one or more frequencies. A cohort of children was retested with conventional audiometry in a hospital-based sound booth. Factors influencing false-positive examinations, including ambient noise and behavior, were examined.
Results: All children with hearing loss were detected using an automated, manual, or two-step (those referred from automated testing were tested manually) protocol in the school (sensitivity = 100%). Specificity was 76% for automated testing, 97% for manual testing, and 99% for the two-step protocol. The variability between thresholds obtained with automated testing was greater than manual testing when compared with conventional audiometry. The percentage of participant responses when no stimulus tone was presented during automated testing was higher in children with false-positive examinations.
Conclusion: A Wireless Automated Hearing-Test System identified all children with hearing loss in a challenging field setting. A two-step protocol (those referred from automated testing are tested manually) reduced false-positive examinations and unnecessary referrals. Children who respond frequently when no tone is presented are more likely to have false-positive automated examinations and should be tested manually.

Risks of Intracochlear Pressures From Laser Stapedotomy

01-03-2020 – Misch, Emily S.; Banakis Hartl, Renee M.; Gubbels, Samuel P.; Greene, Nathaniel T.

Journal Article

Hypothesis: Surgical manipulations during laser stapedotomy can produce intracochlear pressure changes comparable to pressures created by high-intensity acoustic stimuli.
Background: New-onset sensorineural hearing loss is a known risk of stapes surgery and may result from pressure changes from laser use or other surgical manipulations. Here, we test the hypothesis that high sound pressure levels are generated in the cochlea during laser stapedotomy.
Methods: Human cadaveric heads underwent mastoidectomy. Fiber-optic sensors were placed in scala tympani and vestibuli to measure intracochlear pressures during key steps in stapedotomy surgery, including cutting stapedius tendon, lasering of stapedial crurae, crural downfracture, and lasering of the footplate.
Results: Key steps in laser stapedotomy produced high-intensity pressures in the cochlea. Pressure transients were comparable to intracochlear pressures measured in response to high intensity impulsive acoustic stimuli.
Conclusion: Our results demonstrate that surgical manipulations during laser stapedotomy can create significant pressure changes within the cochlea, suggesting laser application should be minimized and alternatives to mechanical downfracture should be investigated. Results from this investigation suggest that intracochlear pressure transients from stapedotomy may be of sufficient magnitude to cause damage to the sensory epithelium and affirm the importance of limiting surgical traumatic exposures.

Correlation Between Electrocochleographic Changes During Surgery and Hearing Outcome in Cochlear Implant Recipients: A Case Report and Systematic Review of the Literature

01-03-2020 – Dalbert, Adrian; Rohner, Peter; Roosli, Christof; Veraguth, Dorothe; Huber, Alexander; Pfiffner, Flurin

Journal Article

Objective: To determine the correlation between intraoperative changes of electrocochleography (ECoch
G) responses and traumatic cochlear implant insertions as well as postoperative hearing loss.
Methods: ECoch
G, radiological, and audiological data were collected prospectively in a cochlear implant recipient with otosclerosis and assumed cochlear trauma during electrode insertion. A systematic review was conducted within PubMed-NCBI, EMBASE, and the Cochrane Library using the terms “Cochlear implant” and “Electrocochleography.” Original studies that evaluated intraoperative ECoch
G responses and postoperative hearing loss were selected and analyzed.
Results: The case report revealed a drop of intra- and extracochlear ECoch
G signals during electrode insertion. The postoperative computed tomography scan suggested a scalar dislocation. There was no measurable hearing 4 weeks after surgery. Within the database search, nine articles met the inclusion criteria. All were case series reports (range from 2 to 36 subjects) with a total of 173 subjects. Due to the heterogeneous data, a meta-analysis was unfeasible.
Conclusions: In concordance with some findings in the literature, the presented case report suggests that a drop of intra- and extracochlear ECoch
G signals during the insertion of the electrode array is associated with cochlear trauma and postoperative hearing loss in some cases. However, the literature is inconclusive regarding the correlation between intraoperative changes of the ECoch
G signals and postoperative hearing preservation. More studies investigating the correlation are needed to provide sufficient data.

Assessment of Temporal Fine Structure Processing Among Older Adults With Cochlear Implants

01-03-2020 – Sladen, Douglas P.; Peterson, Ann; Olund, Amy

Journal Article

Objectives: The purpose of this study was to determine if older adults with cochlear implants are able to take advantage of coding schemes that preserve temporal fine structure (TFS) cues.
Design: A total of 19 older adults with cochlear implants participated in a prospective, repeated measures, A to B design. Participants entered the study using TFS. The participants used strategy A (high definition continuous interleaved sampling HDCIS) for 3 months and strategy B (TFS) for 3 months. Endpoint testing was administered at the end of each 3-month period. Testing included consonant recognition, speech understanding in noise, temporal modulation thresholds, and self-perceived benefit.
Results: Older adults were able to use TFS successfully. Speech perception performance was improved using TFS compared with HDCIS for voicing, but not manner or place of articulation. There were no differences between the two strategies for speech understanding in noise, temporal modulation detection, or self-perceived benefit. At the end of the study, 13 out of 19 (68%) of participants chose to continue using TFS processing.
Conclusions: Advanced age does not prevent adults with cochlear implants from using TFS coding strategies. Performance outcomes using TFS and HDCIS were similar, with the exception of voicing which was improved when using TFS. The data support the idea of using various sound processing strategies with older adults.

Endoscope-assisted Partial Cochlectomy for Intracochlear Schwannoma With Simultaneous Cochlear Implantation: A Case Report

01-03-2020 – Ma, Andrew K.; Patel, Nirmal

Journal Article

Introduction: Intralabyrinthine schwannomas are a small subset of vestibular schwannomas which originate within the labyrinthine structures. Management typically consists of watch-and-wait strategies given that surgical intervention will sacrifice hearing. Endoscopic resection of primary intracochlear schwannoma with simultaneous cochlear implantation for a patient with progressive hearing loss and debilitating tinnitus is described.
Patient: A 56-year-old male presenting with asymmetric left sensorineural hearing loss (SNHL) was diagnosed with intracochlear schwannoma on MRI.
Intervention: Surgery was indicated due to tumor growth on serial imaging, worsening SNHL, and severe tinnitus. Partial cochlectomy was performed via transcanal endoscopic approach. Cochlear implantation via mastoidectomy and posterior tympanotomy was simultaneously performed with a CI512 Contour Advanced implant (Cochlear, Sydney, Australia).
Main Outcome Measures: Post partial cochlectomy speech performance.
Results: Preoperative audiometry showed left profound SNHL with 20% speech recognition score despite maximal amplification. Speech perception testing 5 months postoperatively demonstrated good unilateral discrimination when testing the implanted ear alone (BKB sentences 66%, CUNY sentences 79%), open-set comprehension, and excellent binaural performance.
Conclusion: The endoscope offers an additional viable approach to the otic capsule for the removal of intracochlear schwannoma and good audiologic outcomes can be achieved with simultaneous cochlear implantation even after partial cochlectomy.

The Distribution and Prevalence of Macrophages in the Cochlea Following Cochlear Implantation in the Human: An Immunohistochemical Study Using Anti-Iba1 Antibody

01-03-2020 – Okayasu, Tadao; Quesnel, Alicia M.; O’Malley, Jennifer T.; Kamakura, Takefumi; Nadol, Joseph B. Jr.

Journal Article

Hypothesis: Cochlear implantation may cause an increase in the number of macrophages in the human cochlea similar to previous findings in the vestibular endorgans.
Background: Macrophages play a key role in both an inflammatory response and homeostatic maintenance. Recently, an increase in the prevalence of macrophages was demonstrated in the human vestibular endorgans after implantation. However, the prevalence of macrophages in the cochlea after implantation is unclear. The aim of this study was to compare the distribution and prevalence of macrophages in implanted human cochleae and the contralateral unimplanted ears.
Methods: The prevalence of macrophages in the cochlea in 10 human subjects who had undergone unilateral cochlear implantation was studied by light microscopy using anti-Iba1 immunostaining. The densities of macrophages in the osseous spiral lamina (OSL) and Rosenthals canal (RC) in implanted cochleae were compared with the contralateral unimplanted ears. The distribution of macrophage morphology (amoeboid, transitional, and ramified) was also compared.
Results: There were activated and phagocytosing macrophages within the fibrotic sheath surrounding the electrode track and within fibrous tissue with lymphocytic infiltration in implanted ears. The densities of macrophages in OSL and RC in implanted ears were significantly greater than in unimplanted ears in some areas. There was also a difference in the prevalence of macrophage phenotype between the OSL and RC.
Conclusion: An increase in the density of macrophages in the cochlea after cochlear implantation was demonstrated. Both phagocytosis and anti-inflammatory activity of macrophages were suggested by the distribution and prevalence of macrophages in the implanted cochlea.

Cochlear Implantation in Craniometaphyseal Dysplasia

01-03-2020 – Huang, Alice E.; Adkins, Weston J.; Patel, Neil S.

Journal Article

Objective: Describe the first case of cochlear implantation (CI) for auditory rehabilitation of a patient with craniometaphyseal dysplasia (CMD) and progressive mixed hearing loss.
Patients: A 65-year-old woman with known autosomal dominant CMD presented with progressive mixed hearing loss and declining benefit from conventional hearing aids. Computed tomography and magnetic resonance imaging revealed hyperostosis of the entire craniofacial skeleton. Hearing evaluation demonstrated pure-tone thresholds in the profound range bilaterally by air conduction, and bone conduction thresholds that matched aided thresholds for her left ear, though testing was somewhat limited by inability to mask at high air-conduction thresholds. CI candidacy testing confirmed poor word and sentence scores in the right ear.
Intervention: Due to the inability to access the cochlea via a conventional mastoidectomy and facial recess approach, cochlear implantation via a postauricular subtotal petrosectomy approach with ear canal overclosure was performed.
Main Outcome Measures: Post-implantation word and sentence testing.
Results: Despite extensive internal auditory canal stenosis, the patient demonstrated excellent early speech understanding results 5 weeks after device activation. Postimplantation audiologic evaluation showed thresholds between 20 and 30 d
B HL from 250 to 6000 Hz. Word and sentence testing scores were 76% Consonant-nucleus-consonant in quiet (up from 2% preoperatively) and 77% Az
Bio sentences in quiet (up from 10% preoperatively).
Conclusion: This report describes the first description of CI for CMD. Despite the extensive radiologic abnormalities, the patient has demonstrated excellent benefit from implantation. Further study of rare temporal bone dysplasias, such as CMD, is critical to better characterize the progression of otologic disease and determine optimal treatment.

Cognitive Functions in Adults Receiving Cochlear Implants: Predictors of Speech Recognition and Changes After Implantation

01-03-2020 – Zhan, Kevin Y.; Lewis, Jessica H.; Vasil, Kara J.; Tamati, Terrin N.; Harris, Michael S.; Pisoni, David B.; Kronenberger, William G.; Ray, Christin; Moberly, Aaron C.

Journal Article

Hypotheses: Significant variability in speech recognition outcomes is consistently observed in adults who receive cochlear implants (CIs), some of which may be attributable to cognitive functions. Two hypotheses were tested: 1) preoperative cognitive skills assessed visually would predict postoperative speech recognition at 6 months after CI; and 2) cochlear implantation would result in benefits to cognitive processes at 6 months.
Background: Several executive functioning tasks have been identified as contributors to speech recognition in adults with hearing loss. There is also mounting evidence that cochlear implantation can improve cognitive functioning. This study examined whether preoperative cognitive functions would predict speech recognition after implantation, and whether cognitive skills would improve as a result of CI intervention.
Methods: Nineteen post-lingually deafened adult CI candidates were tested preoperatively using a visual battery of tests to assess working memory (WM), processing speed, inhibition-concentration, and nonverbal reasoning. Six months post-implantation, participants were assessed with a battery of word and sentence recognition measures and cognitive tests were repeated.
Results: Multiple speech measures after 6 months of CI use were correlated with preoperative visual WM (symbol span task) and inhibition ability (stroop incongruent task) with moderate-to-large effect sizes. Small-to-large effect size improvements in visual WM, concentration, and inhibition tasks were found from pre- to post-CI. Patients with lower baseline cognitive abilities improved the most after implantation.
Conclusions: Findings provide evidence that preoperative cognitive factors contribute to speech recognition outcomes for adult CI users, and support the premise that implantation may lead to improvements in some cognitive domains.

Cochlear Implant Mapping Through Telemedicine—A Feasibility Study

01-03-2020 – Luryi, Alexander L.; Tower, Jacob I.; Preston, Jessica; Burkland, Adam; Trueheart, Cyndi E.; Hildrew, Douglas M.

Journal Article

Objective: Access to postoperative aural rehabilitation limits cochlear implant (CI) penetration to the candidate population. The purpose of this study was to evaluate the effectiveness of remote CI programming and aural rehabilitation via telehealth.
Study Design and Setting: Retrospective study of one cochlear implant center.
Patients and Intervention: Patients undergoing cochlear implantation from 2015 to 2018 undergoing remote programming as part of routine audiologic follow up.
Main Outcome Measures: Az
Bio scores, impedances, comfort and threshold levels, and responses to the International Outcome Inventory for Hearing Aids questionnaire modified for CIs (IOI-CI).
Results: A total of 22 CIs in 20 patients were included during the study period. Threshold, comfort, and impedance levels were readily obtained via telehealth and were not significantly different between telehealth and live sessions. Az
Bio scores and warble tone pure tone averages were also similar and acceptable in both session modalities. Based on IOI-CI scores, patients were very satisfied with their hearing outcomes.
Conclusions: Using telemedicine, reliable measurements were readily obtained and hearing outcomes after remote programming were comparable to those expected after in-person programming sessions. Patients were overall satisfied with their remote programming sessions. Telehealth is a cost-effective and safe way to deliver post-CI audiologic care, particularly to patients with limited mobility or those in remote locations.

Balloon Eustachian Tuboplasty Combined With Tympanocentesis Is not Superior to Balloon Eustachian Tuboplasty in Chronic Otitis Media With Effusion—A Randomized Clinical Trial

01-03-2020 – Formánková, Debora; Formánek, Martin; Školoudík, Lukáš; Zeleník, Karol; Tomášková, Hana; Chrobok, Viktor; Komínek, Pavel

Journal Article

Objective: Balloon Eustachian tuboplasty (BET) appears to be a promising therapeutic option for Eustachian tube dysfunction. However, data are lacking on its effect in adults with chronic otitis media with effusion (COME) and whether it should be combined with tympanocentesis. The aim of our study was to determine if there is a beneficial effect of BET combined with tympanocentesis compared with BET only and provide data on the effect of BET in adults with COME.
Study Design: Randomized clinical trial.
Setting: Tertiary referral hospital.
Participants: Adults with COME lasting more than 6 months after tympanostomy tube exclusion. Among 40 eligible ears, 30 were randomized to treatment.
Intervention: BET (group 1) versus BET with concurrent tympanocentesis (group 2).
Main Outcome Measures: Tympanometry, Valsalva or Toynbee maneuver with tympanometry verification, Eustachian Tube Dysfunction Questionnaire, and pure-tone audiometry.
Results: A total of 25 patients (14 ears in group 1 and 15 ears in group 2) were included in the analysis. No significant difference in the effect of treatment was found between the groups. When patients were evaluated as one group, after 2, 6, and 12 months, improvement was found in tympanometry in 55, 48, and 48%; in the ability to perform maneuvers in 55, 41, and 41%; in audiometry in 69, 62, and 59%; and in questionnaire scores in 76, 72, and 69%, respectively.
Conclusions: There was no beneficial outcome of tympanocentesis performed concurrently with BET and therefore it should not be routinely recommended. The success of therapy appears to be reduced compared with other pathologies caused by Eustachian tube dysfunction.

International Pediatric Otolaryngology Group (IPOG) Consensus Recommendations: Congenital Cholesteatoma

01-03-2020 – Denoyelle, Françoise; Simon, François; Chang, Kay W.; Chan, Kenny H.; Cheng, Alan G.; Cheng, Alan T.; Choo, Daniel I.; Daniel, Sam J.; Farinetti, Anne; Garabedian, Erea-Noël; Greinwald, John H.; Hoff, Stephen R.; Hone, Stephen; Licameli, Greg R.; Papsin, Blake C.; Poe, Dennis S.; Pransky, Seth; Smith, Richard J. H.; Triglia, Jean-Michel; Walton, Joanna; Zalzal, George; Leboulanger, Nicolas

Journal Article

Objective: To provide recommendations to otolaryngologists and allied physicians for the comprehensive management of children who present with signs and symptoms of congenital cholesteatoma.
Methods: A two-iterative Delphi method questionnaire was used to establish expert recommendations by the members of the International Pediatric Otolaryngology Group, on the preoperative work-up, the perioperative considerations, and follow-up.
Results: Twenty-two members completed the survey, in 14 tertiary-care center departments representing 5 countries. The main consensual recommendations were: a precise otoscopic description of the quadrants involved, extensive audiological workup (bilateral tonal, vocal audiometry, and BERA), and a CT scan are required. Facial nerve monitoring and a combination of microscope and telescope are recommended for surgical removal. Clinical and audiological follow-up should be pursued yearly for at least 5 years. First MRI follow-up should be done at 18 months postoperatively if the removal violated the matrix. MRI follow-up duration depends on the initial extent of the cholesteatoma.
Conclusion: The goal of preoperative and follow-up consensus from International Pediatric Otolaryngology Group participants is to help manage infants and children with congenital cholesteatoma. The operative techniques may vary, and experienced surgeons must perform these procedures.

Bone Pate Obliteration in Canal Wall Down Mastoidectomy: Modifications of an Established Technique

01-03-2020 – Fischer, Jakob L.; Nesbitt, Nicholas B.; Littlefield, Philip D.

Journal Article

Objective: To describe outcomes with obliteration of the mastoid and medial attic following canal wall down mastoidectomy for cholesteatoma. Our technique uses bone pate in the mastoid and cartilage in the epitympanum and supratubal recess.
Study Design: Retrospective observational study.
Setting: Tertiary medical center.
Patients: Ten years of sequential canal wall down mastoidectomies with obliteration from one neurotologist were reviewed. This included primary and revision cases in adults and children.
Main Outcome Measures: Complications, location and extent of cholesteatoma, the presence of a dry ear after surgery, cholesteatoma recidivism, revision procedures, and postoperative hearing.
Results: Seventy-eight patients (79 ears) met inclusion criteria. There were few major complications. There was active follow-up of a year or more in 61. For these, the mean follow-up was 3.1 years, and approximately 90% had a dry cavity for the remainder of their follow-up. About half required minimal (if any) maintenance. There were five cases with residual disease, and no cases with recurrent disease. There were five cases that were considered failures, with three taking several years to manifest. There were no cases where cholesteatoma was buried in bone pate. A sizeable minority continued to have active tubotympanic disease despite successful treatment of the attic and mastoid.
Conclusions: This seems to be a safe and reliable means to eradicate cholesteatoma and create a dry, low-maintenance cavity. It is not a cure for tubotympanic disease, and a small minority of initially stable cavities may fail several years following surgery.
Level of Evidence: 4.

Hearing Recovery After Ejection of Air in a Case of Traumatic Pneumolabyrinth: Mechanism and Management Options

01-03-2020 – Oda, Kiyoshi; Yamamoto, Hiroki; Kobayashi, Toshimitsu; Hidaka, Hiroshi; Ikeda, Ryoukichi; Yoshida, Naohiro

Journal Article

Objective: To describe a case of traumatic pneumolabyrinth and subsequent hearing recovery after ejection of air with transcanal endoscopic surgical exploration.
Patients: A 38-year-old man was struck by his child while cleaning his ear with an ear pick made of bamboo, which penetrated deep into the left ear canal. Severe vertigo with vomiting and left hearing impairment ensued. In addition, high-resolution computed tomography demonstrated an air density within the vestibule.
Interventions: Exploratory tympanotomy was performed endoscopically a day after the injury and air was ejected from the oval window surgically.
Main Outcome Measures: High-resolution computed tomography, audiologic testing.
Results: Several hours after surgery, the patients subjective vestibular symptoms lessened and 7 days after surgery, the patient felt slight dizziness when moving his head and no apparent spontaneous nystagmus was observed with an infrared charge-coupled device camera and was discharged from the hospital. Two years later, there are no subjective vestibular symptoms at all and the pure-tone average of his left ear improved to 16.7 d
B.
Conclusion: We presented a case of traumatic pneumolabyrinth and the subsequent hearing recovery after ejection of air following endoscopic exploratory tympanotomy. We propose that initial management for traumatic pneumolabyrinth should be ejection of the air bubble if it is located solely in the vestibule and sparing the cochlea.

Role of Macrophage Migration Inhibitory Factor in NLRP3 Inflammasome Expression in Otitis Media

01-03-2020 – Kariya, Shin; Okano, Mitsuhiro; Zhao, Pengfei; Maeda, Yukihide; Kataoka, Yuko; Higaki, Takaya; Makihara, Seiichiro; Nishihira, Jun; Tachibana, Tomoyasu; Nishizaki, Kazunori

Journal Article

Hypothesis: Macrophage migration inhibitory factor plays an important role in the expression of interleukin (IL)-1β and the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in lipopolysaccharide-induced otitis media.
Background: NLRP3 inflammasome and macrophage migration inhibitory factor are critical molecules mediating inflammation. However, the interaction between the NLRP3 inflammasome and macrophage migration inhibitory factor has not been fully examined.
Methods: Wild-type mice and macrophage migration inhibitory factor gene-deficient (MIF−/−) mice received a transtympanic injection of either lipopolysaccharide or phosphate-buffered saline. The mice were sacrificed 24 hours after the injection. Concentrations of IL-1β, NLRP3, ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain and a pyrin domain), and caspase-1 in the middle ear effusions were measured by enzyme-linked immunosorbent assay. Temporal bones were processed for histologic examination and immunohistochemistry.
Results: In the immunohistochemical study using the wild-type mice, positive staining of macrophage migration inhibitory factor, NLRP3, ASC, and caspase-1 were observed in infiltrating inflammatory cells induced by lipopolysaccharide in the middle ear. The number of inflammatory cells caused by lipopolysaccharide administration decreased remarkably in the MIF−/− mice as compared with the wild-type mice. The concentrations of IL-1β, NLRP3, ASC, and caspase-1 increased in the lipopolysaccharide-treated wild-type mice. The MIF−/− mice with lipopolysaccharide had decreased levels of IL-1β, NLRP3, ASC, and caspase-1 as compared with the wild-type mice.
Conclusion: Macrophage migration inhibitory factor has an important role in the production of IL-1β and the NLRP3 inflammasome. Controlling the inflammation by modulating macrophage migration inhibitory factor and the NLRP3 inflammasome may be a novel therapeutic strategy for otitis media.

Temporal Bone Anatomy in Superior Semicircular Canal Dehiscence: A Case Control Study on Bone Pneumatization and the Level of Middle Cranial Fossa

01-03-2020 – Tikka, Theofano; Kontorinis, Georgios

Journal Article

Objectives: To assess for any association between the presence of superior semicircular canal dehiscence (SSCD) and temporal bone pneumatization and the height of middle fossa in symptomatic patients.
Study Design: Retrospective case-control study.
Setting: Tertiary, university referral center.
Patients: Symptomatic patients with SSCD and a matched group of non-SSCD patients.
Intervention: High-resolution computed tomography of the temporal bones.
Main Outcome Measures: We graded the temporal bone pneumatization using the Virapongse classification and measured the distance between the middle fossa and the lateral semicircular canal on coronal plane at the most anterior aspect of the lateral and superior semicircular canals. We statistically compared all parameters (level of significance 0.05).
Results: We enrolled 30 patients with SSCD, (males = 13, females = 17) with mean age of 47 years (SD: 26). The matched control group had similar baseline characteristics (p > 0.05). Grade 4 pneumatization was noted in 83.3% (n = 25) of SSCD patients with the remainder having grade 3. In the control group, 46.6% (n = 14) had a grade 4 pneumatization, 36.6% (n = 11) grade 3 and 16.6 5 (n = 5) grade 2. This difference was statistically significant (p = 0.003). The difference in the height of the middle cranial fossa between the two groups was also statistically significant (mean 3.80 SD: 0.84 in SSCD group and 4.68 mm SD: 0.85 in the control group; p < 0.0001).
Conclusions: We found better-pneumatized mastoids in patients with SSCD, indicative of a direct association between temporal bone pneumatization and SSCD. Additionally, the middle fossa dura is lying significantly lower in patients with SSCD, factor of surgical importance.

The Role of Obesity in Iatrogenic Encephaloceles of the Temporal Bone

01-03-2020 – Lindquist, Nathan R.; Appelbaum, Eric N.; Sweeney, Alex D.; Vrabec, Jeffrey T.

Journal Article

Objective: Acquired encephaloceles of the temporal bone may be traumatic, spontaneous, or from chronic ear disease or previous surgery. Iatrogenic encephaloceles arise in the setting of previous mastoidectomy and traditionally involve both bony dehiscence and dural injury. We aim to classify and analyze the pathogenesis, clinical presentation, and treatment options for patients with iatrogenic tegmen defects and encephaloceles of the temporal bone.
Study Design: Retrospective chart review.
Setting: Single tertiary academic center.
Patients: Subjects with iatrogenic tegmen defects and encephaloceles of the temporal bone were included.
Intervention: Patient demographics, history, symptoms, radiographic data, intraoperative findings, management, follow-up, and outcomes were recorded.
Outcome Measures: Primary outcome measures included patient characteristics, time from primary otologic surgery to surgical repair, location of the defect, and management strategy including surgical approach, methods, and follow-up.
Results: Iatrogenic tegmen injuries or encephaloceles were identified in 18 patients and divided into intentional or unintentional. The latter group presented immediately, early, or late, as determined by intraoperative identification or from delayed symptoms. Eleven patients presented late with previously unrecognized encephaloceles. Compared with patients presenting with incidentally noted tegmen dehiscence during revision mastoidectomy, a significant proportion of patients with late encephaloceles had BMI ≥30 kg/m2 (p = 0.03).
Conclusion: The majority of iatrogenic encephaloceles are unintentional, unrecognized, and may present many years after primary surgery. Similar to spontaneous encephaloceles of the temporal bone, obesity is associated with iatrogenic encephaloceles, although the rate of progression and timing is unclear. We recommend primary repair of any unintentional tegmen defect encountered during mastoid surgery, especially in obese patients.

Long-term Audiometric Outcomes After Atresiaplasty for Congenital Aural Atresia

01-03-2020 – Imbery, Terence E.; Gray, Lincoln; Champaloux, Eve; Kesser, Bradley W.

Journal Article

Objective: Describe long-term trends and stability of hearing outcomes for patients undergoing primary congenital aural atresia (CAA) repair.
Study Design: Retrospective chart review.
Setting: Single academic, tertiary referral center.
Patients: Children and adults who underwent primary CAA repair between 1980 and 2017.
Intervention: CAA repair.
Main Outcome Measures: Long-term (> 1 yr) postoperative three-tone (500, 1000, 2000 Hz) air conduction pure-tone average (AC PTA) compared with the immediate (within 90 d of surgery) postoperative audiogram.
Results: The mean preoperative AC PTA was 59.6 d
B HL. CAA repair improved hearing an average of 30.5 d
B, but hearing declined by 8.2 d
B over the long-term follow-up period (mean 4.4 yr; range 1–15.7 yr), leaving a final mean improvement of 22.2 d
B (final mean AC PTA 37.3 d
B HL). Two-thirds (92 of 138 ears) had an AC PTA ≤ 30 d
B HL recorded in the first year after surgery. At the last follow-up test, 64% had “stable” hearing defined as no more than a 10 d
B decline in AC PTA compared with the immediate postoperative audiogram; 21% had a 10 to 20 d
B decline, 8% a 20 to 30 d
B decline, and 7% declined > 30 d
B.
Conclusions: All patients enjoyed improvement in AC PTA after surgery (preoperative minus the best postoperative PTA, mean = 34 d
B, range = 3.3–52 d
B). Hearing declined by an average 8.2 d
B over the long-term leaving a final average AC PTA of 37.4 d
B HL. Sixty-four percent of patients exhibited stable (< 10 d
B loss) hearing over time; 36% lost 10 d
B or more over the long-term follow-up period. Hearing results typically stabilize over time with most of the change occurring in the first 3 years after CAA repair. Bone conduction thresholds remained stable over the study period.

Hearing in Noise With Unilateral Versus Bilateral Bone Conduction Hearing Aids in Adults With Pseudo-conductive Hearing Loss

01-03-2020 – Hilly, Ohad; Sokolov, Meirav; Finkel, Reut Beck; Zavdy, Ofir; Shemesh, Rafael; Attias, Joseph

Journal Article

Objective: The role of bilateral bone conduction amplification in patients with bilateral conductive hearing loss is unclear because cranial attenuation is usually considered negligible, and both cochleae can be stimulated with similar efficacy by each device. The aim of the study was to determine if bilateral bone-conduction hearing aids can improve hearing in noise in a homogeneous group of normal-hearing subjects with bilateral pseudo-conductive hearing loss.
Study Design: Prospective, comparative.
Setting: Department of Communication Sciences and Disorders in University of Haifa, Israel.
Subjects: Department of Communication Sciences and Disorders in University of Haifa, Israel.
Interventions: Induction of bilateral pseudo-conductive hearing loss of more than 35 d
B using earplugs and earmuffs.
Main Outcome Measures: Hearing quality on blinded comparison of unilateral versus bilateral amplification with bone-conduction hearing aids under different locations of noise.
Results: Unilateral and bilateral amplification had similar efficacy when both signal and noise were presented from the front. However, bilateral amplification was significantly better when signals were presented from the front and noise was presented from both sides (SNR −10: 92% vs. 84%, p  = 0.001; SNR −15: 84% vs. 78%, p  = 0.005). Analysis of subject responses on blinded questionnaires revealed that 81% found hearing easier with bilateral amplification. Noise was reported to be more disturbing with unilateral amplification by 55% of the subjects and with bilateral amplification, by 9%.
Conclusions: Bilateral amplification with bone conduction devices can improve understanding in noise in the binaural squelch setting. Subjective improvements with bilateral bone-conduction aids included better sound quality and reduced noise disturbance. These findings are consistent with the binaural mechanism of spectral release from masking.

A Possible Role of Video-Head Impulse Test in Detecting Canal Involvement in Benign Paroxysmal Positional Vertigo Presenting With Positional Downbeat Nystagmus

01-03-2020 – Castellucci, Andrea; Malara, Pasquale; Delmonte, Silvia; Ghidini, Angelo

Journal Article

Objective: To describe the possible diagnostic role of video-head impulse test (v
HIT) in patients presenting with positional downbeat nystagmus (PDN) due to benign paroxysmal positional vertigo (BPPV) involving the anterior canal (AC) or the non-ampullary arm of the posterior canal (PC).
Patients: Three patients presenting with positional vertigo, PDN, symmetrical cervical and ocular vestibular-evoked myogenic potentials, and selective deficit of the vestibulo-ocular reflex (VOR) gain for a single vertical canal on v
HIT.
Interventions: Diagnostic evaluation and rehabilitative treatment for BPPV involving the deficient canals.
Main Outcome Measures: Video-oculographic and v
HIT findings before and after canalith repositioning procedures (CRP) for AC-BPPV and apogeotropic PC-BPPV.
Results: Each patient was treated with CRP for BPPV involving the hypoactive canal. In one case, symptoms receded with physical therapy, whereas two patients developed a paroxysmal positional upbeat nystagmus consistent with BPPV involving the ampullary arm of the ipsilateral PC and were treated with Epley CRP. Posttreatment evaluation showed resolution of symptoms and signs and restitution of canal function in all cases.
Conclusions: PDN can be due to both peripheral and central vestibular pathologies. In case of BPPV, involvement of the non-ampullary arm of the PC is hardly distinguishable from contralateral AC canalolithiasis. In these situations, v
HIT may play a key role in the differential diagnosis. Considering these findings, we propose to include v
HIT in the test battery of patient with PDN, as it may provide clues to the differential diagnosis with central pathologies enabling the identification of the canal involved by BPPV.

Association Between Vestibular Migraine and Migraine Headache: Yet to Explore

01-03-2020 – Abouzari, Mehdi; Goshtasbi, Khodayar; Moshtaghi, Omid; Tan, Donald; Lin, Harrison W.; Djalilian, Hamid R.

Journal Article

Objectives: To evaluate if patients with a diagnosis of vestibular migraine (VM) by the International Classification of Headache Disorders (ICHD) criteria have meaningful differences in symptomatology and disease characteristics when compared to patients with concurrent vestibular symptoms and migraine that do not meet ICHD criteria.
Methods: Patients who presented for the evaluation of vertigo were provided a detailed questionnaire about dizziness and migraine symptoms. Patients were assigned to either VM cohort (met ICHD criteria for VM) or migraine headache (MH) cohort (met ICHD criteria for migraine with or without aura but not VM). Disease characteristics, symptomatology, quality of life, and perceived stress score were compared between the cohorts.
Results: The VM cohort demonstrated a shorter duration of vertigo episodes, 11 ± 22 hours versus 84 ± 146 hours in the MH cohort. In the VM cohort, 81% reported experiencing migraine headaches during episodes of vertigo, versus 61% in the MH cohort. All patients in the VM cohort reported a previous diagnosis of migraine headache, whereas 9% of the MH cohort had not been previously diagnosed by another physician. There was no difference in quality of life or perceived stress scores between the cohorts.
Conclusions: A large proportion of vertigo patients with migrainous features do not meet the ICHD criteria for VM. The differences between cohorts represent selection bias rather than meaningful features unique to the cohorts. As such, VM and MH with vestibular symptoms may exist on a spectrum of the same disease process and may warrant the same treatment protocols.

Hyperventilation Syndrome: Investigating the Relationship Between Nijmegen Questionnaire, Vestibular Function Tests, and Patient Symptoms

01-03-2020 – Williams, Christopher Y. K.; Williams, Robert W. K.; Knight, Richard; Hashmi, Syed; Donnelly, Neil; Bance, Manohar

Journal Article

Objective: To explore the Nijmegen Questionnaire (NQ) and its relationship to vestibular function tests and symptoms in patients with dizziness; to compare patient characteristics between those with a positive Nijmegen score and patients clinically diagnosed with hyperventilation syndrome (HVS).
Study Design: Retrospective case series.
Setting: Tertiary neurotology referral center.
Patients: Patients seen at vestibular assessment were grouped according to positive (≥24) or negative ( 0.05). Symptoms commonly described by patients with positive Nijmegen scores include “blurred vision,” “tingling,” “anxiety,” “shortness of breath,” “palpitations,” “panic,” “numbness,” “chest pain,” and “chest tightness.” In contrast, when grouped by HVS diagnosis, patients with HVS were significantly more likely to have No Lesion detected on vestibular function testing (p = 0.0366). “Panic,” “anxiety,” and “tingling” were the only significant symptoms reported more often in the HVS diagnosis group, while “nausea/vomiting” and “vertigo” were reported significantly less frequently compared with the non-HVS diagnosis group.
Conclusions: Hyperventilation is a complex stimulus, with some effects manifesting in neurotology clinics. This study reveals discrepancies in both vestibular assessment findings and symptom profiles between patients with a positive screening score in the NQ and patients clinically diagnosed with hyperventilation syndrome. This data will inform clinicians’ interpretation of the NQ in the neurotologic setting.

Comorbid Cupulolithiasis Is Rare in Patients With Horizontal Semicircular Canal Canalolithiasis

01-03-2020 – Choi, BoYoon; Nahm, HyunJoo; Shin, Jung Eun; Kim, Chang-Hee

Journal Article

Objectives: Considering that otolith particles pass through the canal until attaching to the cupula in the canal-side horizontal semicircular canal (HSCC) cupulolithiasis, comorbidity of HSCC canalolithiasis and cupulolithiasis may occur. We aimed to investigate the incidence of comorbidity of cupulolithiasis in patients with HSCC canalolithiasis and to improve treatment efficacy.
Study Design: Retrospective study.
Setting: Tertiary referral academic center.
Patients: Ninety-seven consecutive patients with HSCC canalolithiasis between March 2017 and March 2019 were included.
Main Outcome Measures: Coexistence of HSCC cupulolithiasis was hierarchically investigated. 1) Spontaneous reversal of initial nystagmus is observed bilaterally in a head-roll test (HRT), 2) nystagmus is in the same direction at each of the three times the supine position was tested, and 3) both bowing and leaning nystagmus with opposite direction are observed.
Results: Of 97 patients with HSCC canalolithiasis, 2 patients (2%) had comorbid HSCC cupulolithiasis.
Conclusions: Although coexistence of HSCC canalolithiasis and cupulolithiasis should be considered when spontaneous reversal of nystagmus direction is observed without position change during a HRT, the incidence of coexistence is very low. However, canalith repositioning maneuvers for both canalolithiasis and cupulolithiasis should be performed in cases with comorbidity.

The Direct Costs of Microsurgical Resection of Vestibular Schwannomas

01-03-2020 – Saliba, Joe; Mohammadzadeh, Amir; Tawfik, Kareem O.; Carriere, Junie S.; Schwartz, Marc S.; Nguyen, Quyen T.; Friedman, Rick A.

Journal Article

Objective: To determine and itemize surgical costs associated with the translabyrinthine (TL), retrosigmoid (RS), and middle cranial fossa (MCF) approaches for microsurgical excision of vestibular schwannoma (VS).
Study Design: Retrospective cost analysis study.
Setting: Tertiary referral center.
Patients: Thirty consecutive adult patients underwent microsurgical excision of VS by either TL, RS, or MCF approach (10 per approach).
Interventions: Microsurgical excision of VS by one of the three major approaches. Medical and financial data were collected.
Main Outcome Measures: Total operating room time (minutes), skin-to-skin time (minutes), operating room cost ($US), and surgical supplies cost ($US).
Results: The MCF approach was associated with the shortest skin-to-skin time (230.3 min, p < 0.001). Mean overall nonsurgical room time was 94.7 minutes and not significantly different among approaches (p = 0.55). Mean total surgical supplies cost was $5,028 and was the highest for the RS ($7,116; p < 0.001) but not significantly different between TL and MCF. Mean operating room services charges were $68,417 overall and were the lowest for the MCF group ($53,306; p = 0.01). Tumor size was not correlated with surgical supplies cost (p = 0.74). The items associated with the highest average cost per case were the surgical aspirator ($1,062), drill burs ($928), and titanium implants ($575). There was redundancy in multiple surgical items such as drill burs, hemostatic agents, and sutures.
Conclusion: This study is the first to provide a detailed itemization of the surgical expenses specific to VS resection. Elevated nonsurgical room time and supply redundancy provides the opportunity for decreasing surgical costs and waste.

Metformin Potential Impact on the Growth of Vestibular Schwannomas

01-03-2020 – Feng, Austin Y.; Enriquez-Marulanda, Alejandro; Kouhi, Ali; Ali, Noor-E-Seher; Moore, Justin M.; Vaisbuch, Yona

Journal Article

Objective: Previous work has suggested that metformin may possess antineoplastic properties. This study aims to assess the effect of metformin on the growth of sporadic vestibular schwannomas.
Methods: A retrospective cohort study was performed on patients presenting with radiologically confirmed vestibular schwannomas to Stanford medical center between January 1990 and October 2018. Patients who received metformin during the follow-up period were included and were compared with the control group who were not receiving metformin. Tumor progression and hearing loss are primary and secondary outcomes, respectively.
Results: A total of 149 patients were analyzed, with 42 patients receiving metformin. The mean age at presentation is 69.6 (±11.7) years. There are 69 (46.3%) females and 80 (53.7%) males and there is no significant age difference between the groups. Tumor size at presentation is similar between both groups, 8 mm (4–13) in control group and 7.5 mm (4–14) in metformin group. The average follow-up period is 34.2 months (18.3–57.8) and 30.3 months (13.6–69.8) in the metformin and control cohorts, respectively, and they are not significantly different. No significant differences between both groups were found in final American Academy of Otolaryngology – Head and Neck Surgery hearing outcome or poor audiogram outcome. Metformin users are significantly less likely to present with tumor growth at final follow-up compared with nonmetformin users (28.6 versus 49.5%, respectively; p = 0.02).
Conclusions: This preliminary result suggests metformin may reduce vestibular schwannoma tumor growth rate and shows potential promise as a novel chemotherapeutic agent. Further studies are needed to validate this finding.

An Update on Epidemiology and Management Trends of Vestibular Schwannomas

01-03-2020 – Pandrangi, Vivek C.; Han, Albert Y.; Alonso, Jose E.; Peng, Kevin A.; St. John, Maie A.

Journal Article

Objective: To determine the current epidemiology and management trends for patients with vestibular schwannomas (VS).
Study Design: Retrospective cohort study.
Setting: The Surveillance, Epidemiology, and End Results (SEER) tumor registry.
Patients: The SEER database was queried to identify patients diagnosed with VS from 1973 to 2015. Demographics, patient and tumor characteristics, and treatment methods were analyzed.
Results: A total of 14,507 patients with VS were identified. The mean age at diagnosis was 55 ± 14.9 years. Age-adjusted incidence from 2006 to 2015 was 1.4 per 100,000 per year and remained relatively stable. Incidence across age varied with sex, as younger women and older men had increased incidences comparatively. A higher percentage of patients underwent surgery alone (43%), followed by observation (32%), radiation alone (23%), and combined radiation and surgery (2%). Age 65 and older was associated with observation (odds ratio OR 1.417; p = 0.029) whereas age 20 to 39 and 40 to 49 were associated with surgery (OR 2.013 and 1.935; p < 0.001). Older age was associated with radiation. Larger tumor size was associated with surgery and combined treatment. African American patients and American Indian or Alaskan Native patients were more likely to undergo observation than surgery.
Conclusions: The overall incidence of VS is 1.4 per 100,000 per year and has remained relatively stable. There is a trend toward more conservative management with observation, which may be secondary to earlier diagnosis given widespread use of magnetic resonance imaging. Further studies are necessary to investigate differences in disease patterns and disparities in management.

Functional Outcomes Following Temporomandibular Joint Dissection Performed During Surgery for Skull Base Tumors

01-03-2020 – Wei, Xingmei; Gao, Zhiqiang; Zhang, Tao; Zhang, Zhuhua; Tian, Xu; Zhao, Yang; Zhou, Yalin; Feng, Guodong

Journal Article

Background: During skull base tumor surgery, temporomandibular joint (TMJ) dissection is commonly performed. The impact of this procedure on patients’ postoperative diet and TMJ function is a matter of concern to surgeons.
Methods: We reviewed the Craniomandibular Index (CMI) for 32 patients (15 men and 17 women) who underwent TMJ dissection during surgery for skull base tumors between August 2015 and May 2018.
Results: Fifteen patients underwent removal of the mandibular condyle, and 17 had the condyle preserved. Twenty-one patients mainly underwent infratemporal fossa approach, and 11 underwent extended temporal bone resection. No significant difference between pre- and postoperative diet was observed in any group. Significant differences in CMI index were seen in all groups. The highest score was 0.115 of Dysfunction Index, observed postoperatively in the group that underwent condyle removal.
Conclusions: For skull base tumor surgery, TMJ dissection has no significant impact on postoperative diet. Patients who underwent removal of the mandibular condyle have significantly worse postoperative TMJ function.

Electrocochleography During Translabyrinthine Approach for Vestibular Schwannoma Removal

01-03-2020 – Riggs, William J.; Fitzpatrick, Douglas C.; Mattingly, Jameson K.; Harris, Michael S.; Hiss, Meghan M.; Rajkumar, Shashank; Zhan, Kevin Y.; Brown, Kevin D.; Moberly, Aaron C.; Dodson, Edward E.; Adunka, Oliver F.

Journal Article

Hypothesis: Intraoperative electrocochleography (ECoch
G) 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 ECoch
G 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” (ECoch
G-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 ECoch
G-TR, with word recognition score (WRS), was moderate (r = 0.67), as well as the correlation between pure-tone averages and ECoch
G (r = 0.63). The cochlea remained functional in two cases of sudden sensorineural hearing loss with 0% WRS.
Conclusion: Reduced ECoch
G-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.

Intrinsic Measures and Shape Analysis of the Intratemporal Facial Nerve

01-03-2020 – Hudson, Thomas J.; Gare, Bradley; Allen, Daniel G.; Ladak, Hanif M.; Agrawal, Sumit K.

Journal Article

Hypothesis: To characterize anatomical measurements and shape variation of the facial nerve within the temporal bone, and to create statistical shape models (SSMs) to enhance knowledge of temporal bone anatomy and aid in automated segmentation.
Background: The facial nerve is a fundamental structure in otologic surgery, and detailed anatomic knowledge with surgical experience are needed to avoid its iatrogenic injury. Trainees can use simulators to practice surgical techniques, however manual segmentation required to develop simulations can be time consuming. Consequently, automated segmentation algorithms have been developed that use atlas registration, SSMs, and deep learning.
Methods: Forty cadaveric temporal bones were evaluated using three dimensional micro
CT (μCT) scans. The image sets were aligned using rigid fiducial registration, and the facial nerve canals were segmented and analyzed. Detailed measurements were performed along the various sections of the nerve. Shape variability was then studied using two SSMs: one involving principal component analysis (PCA) and a second using the Statismo framework.
Results: Measurements of the nerve canal revealed mean diameters and lengths of the labyrinthine, tympanic, and mastoid segments. The landmark PCA analysis demonstrated significant shape variation along one mode at the distal tympanic segment, and along three modes at the distal mastoid segment. The Statismo shape model was consistent with this analysis, emphasizing the variability at the mastoid segment. The models were made publicly available to aid in future research and foster collaborative work.
Conclusion: The facial nerve exhibited statistical variation within the temporal bone. The models used form a framework for automated facial nerve segmentation and simulation for trainees.

Mechanical Energy Dissipation Through the Ossicular Chain and Inner Ear Using Laser Doppler Vibrometer Measurement of Round Window Velocity

01-03-2020 – Ryan, Matthew; Lally, John; Adams, Jason K.; Higgins, Sophie; Ahmed, Mostafa; Aden, James; Esquivel, Carlos; Spear, Samuel A.

Journal Article

Hypothesis: Round window velocity measurements should correlate closely with vibration measurements taken at proximal points along an intact chain over a set frequency range. These round window vibration measurements should be similar to the vibration measurements taken of the ossicles if mechanical energy is conserved through the vestibular organ.
Background: To date there has not been a study which compares vibratory velocity measurements through an intact ossicular chain to the level of the round window. This study attempted to quantify the degree of mechanical energy transmission and suspected dissipation through the ossicular chain and vestibular organ through incus, stapes, and round window velocity measurements in response to sound stimulus.
Methods: Five thawed human temporal bones with intact ossicular chain and tympanic membrane underwent complete mastoidectomy and a facial recess approach. A laser Doppler vibrometer (LDV) was mounted on the operating microscope to measure vibration of incus, stapes, and round window in response to a sound stimulus within the external auditory canal. Sound stimulus frequencies ranged from 0.5 to 4 k
Hz at 90 d
B SPL.
Results: Vibration velocity was measured across the frequency range for each incus, stapes, and round window. Vibration velocity curves obtained over the frequency range were similar for each of the bones with a notable resonant frequency around 2 k
Hz. The incus and stapes curve amplitudes were nearly identical with similar maximum velocity and frequency at which this maximal velocity was noted. Round window vibration velocity demonstrated a unique peak velocity. Transfer function measurements of the stapes and round window demonstrated markedly similar curves. The variation in velocity between temporal bones in response to the standardized stimulus was more dramatic in the round window measurements when compared with the incus and stapes.
Conclusions: This study supports the concept that round window transfer function is equivalent to stapes footplate transfer function when subjected to the same acoustic stimuli. This study also demonstrates that the round window is a much more difficult target to measure when using LDV technology and improvements in experimental design are required to better understand round window physiology in relation to transfer of acoustic vibratory stimulus transferred throughout the middle ear. A complete and thorough understanding of the biophysical properties of the middle and inner ear are critical for optimal ossiculoplasty outcomes and the development of future ossicular prosthetics.

Replicating Skull Base Anatomy With 3D Technologies: A Comparative Study Using 3D-scanned and 3D-printed Models of the Temporal Bone

01-03-2020 – Chae, Ricky; Sharon, Jeffrey D.; Kournoutas, Ioannis; Ovunc, Sinem S.; Wang, Minghao; Abla, Adib A.; El-Sayed, Ivan H.; Rubio, Roberto Rodriguez

Journal Article

Hypothesis: 3D technologies, including structured light scanning (SLS), microcomputed tomography (micro-CT), and 3D printing, are valuable tools for reconstructing temporal bone (TB) models with high anatomical fidelity and cost-efficiency.
Background: Operations involving TB require intimate knowledge of neuroanatomical structures—a demand that is currently met through dissection of limited cadaveric resources. We aimed to document the volumetric reconstruction of TB models using 3D technologies and quantitatively assess their anatomical fidelity.
Methods: In the primary analysis, 14 anatomical characteristics of right-side TB from 10 dry skulls were measured. Each skull was 3D-scanned using SLS to generate virtual models, which were measured using mesh processing software. Metrics were analyzed using mean absolute differences and one-sample t tests with Bonferroni correction. In the secondary analysis, an individualized right-side TB specimen (TBi) was 3D-scanned using SLS and micro-CT, and 3D-printed on a stereolithography printer. Measurements of each virtual and 3D-printed model were compared to measurements of TBi.
Results: Significant differences between the physical skulls and virtual models were observed for 11 of 14 parameters (p < 0.0036), with the greatest mean difference in the length of petrous ridge (2.85 mm) and smallest difference in the diameter of stylomastoid foramen (0.67 mm). In the secondary analysis, greater mean differences were observed between TBi and virtual models than between TBi and 3D-printed models.
Conclusion: For the first time, our study provides quantitative measurements of TB anatomy to demonstrate that 3D technologies can facilitate individualized and highly accurate reconstructions of TB, which may benefit anatomy education, clinical training, and preoperative planning.

Rhythmic Wave Patterns on Ambient Pressure Tympanometry in Patients With Objective Tinnitus-associated Pathologies

01-03-2020 – Sayyid, Zahra N.; Thai, Anthony; Swanson, Austin; Hosseini, Davood K.; Fitzgerald, Matthew B.; Ma, Yifei; Vaisbuch, Yona

Journal Article

Objective: To introduce the concept of ambient pressure tympanometry (APT) and its association with pathologies that may present with objective tinnitus.
Study Design: Retrospective case series.
Setting: Tertiary referral center.
Subjects and Methods: Audiologists performed APT on adult patients as part of routine audiological testing. Ears with myoclonus and patulous Eustachian tube (PET) were identified via review of patient history and physical examination. All other conditions were verified via computed tomography (CT) temporal bone imaging. Ears with conditions that could impair tympanic membrane compliance, such as otosclerosis or tympanic membrane perforation, were excluded. APT findings were analyzed via a novel algorithm.
Results: A radiographic finding associated with objective tinnitus was confirmed in 67 ears that underwent CT imaging; 45 (67%) of these ears displayed rhythmic APT wave patterns. These included 28 ears with superior semicircular canal dehiscence, 4 ears with sigmoid sinus dehiscence, 6 ears with internal carotid artery dehiscence, 4 ears with glomus tumor, and 3 ears with encephalocele. In addition, we identified three ears with myoclonus and one ear with PET. In a subset of 30 ears with objective tinnitus symptoms that underwent CT imaging, 22 displayed rhythmic waves; of these 22 ears, 20 (91%) had a radiographic finding associated with objective tinnitus.
Conclusions: Rhythmic APT wave patterns are common and may be associated with numerous temporal bone pathologies that may present with objective tinnitus. APT is a simple, rapid, and widely available tool that warrants further study to determine its value in screening of these otologic conditions.

Flat-panel CT Imaging of a Radiopaque Shim for Patulous Eustachian Tube Dysfunction

01-03-2020 – Liao, David; Pearl, Monica S.; Ward, Bryan K.

Journal Article

No abstract available

American Otological Society Preliminary Program

01-03-2020 –

No abstract available

American Neurotology Society Preliminary Program

01-03-2020 –

No abstract available