Assessment of the Eustachian tube: a review.

BACKGROUND: Dysfunction of the Eustachian tube (ET) can lead to negative pressure within the middle ear, which, in turn, causes various pathological changes. Multiple testing methods for ET function have been devised, each with its own advantages and disadvantages. Knowing the characteristics of each ET function test and the unique characteristics of ET dysfunction (ETD) in children are prerequisites for choosing the optimal assessment method. For a comprehensive diagnosis, assessment should also include the localisation of any sites of obstruction. This review aims to summarise the methods of evaluating ET function and locating sites of ET lesions. METHODS: Articles evaluating ET function, localising lesions in the ET, and ETD in children were collected from the PubMed database. We selected only relevant English publications. RESULTS: ETD in children has different characteristics to those in adults. The appropriate tests for assessing ET function depend on the specific conditions of the individual patient. Valsalva computed tomography can provide information on the soft and bony anatomy of the ET to facilitate identification of lesion sites. CONCLUSION: An accurate diagnosis should be based on a combined analysis of objective and subjective results, with interpretation made in conjunction with clinical history and physical examination. A comprehensive assessment should include lesion localisation. When assessing ETD in children, it is important to take into account the characteristics of this population.

Clinician-rated quality of video otoscopy recordings and still images for the asynchronous assessment of middle-ear disease.

INTRODUCTION: Video otoscopy plays an important role in improving access to ear health services. This study investigated the clinician-rated quality of video otoscopy recordings and still images, and compared their suitability for asynchronous diagnosis of middle-ear disease. METHODS: Two hundred and eighty video otoscopy image-recording pairs were collected from 150 children (aged six months to 15 years) by an ear, nose, and throat (ENT) specialist, audiologists, and trained research assistants, and independently rated by an audiologist and ENT surgeon. On a five-point scale, clinicians rated the cerumen amount, field of view, quality, focus, light, and gave an overall rating, and asked whether they could make an accurate diagnosis for both still images and recordings. RESULTS: More video otoscopy recordings were rated as 'good' or 'excellent' compared to still images across all domains. The mean difference between the two otoscopic procedures ratings was significant across almost all domains (p < 0.05), except 'cerumen amount'. The suitability to make a diagnosis significantly improved when using recordings (p<0.05). Younger participant age was found to have a significant, negative impact on the ratings across all domains (p < 0.03). The role of the tester conducting video otoscopy did not have a significant impact on the ratings. DISCUSSION: Video otoscopy recordings were found to provide clearer views of the tympanic membrane and increase the ability to make diagnoses, compared to still images, for both audiologists and ENT surgeons. Research assistants with limited practice were able to obtain video otoscopy images and recordings that were comparable to the ones obtained by clinicians.

Artificial intelligence to diagnose ear disease using otoscopic image analysis: a review.

AI relates broadly to the science of developing computer systems to imitate human intelligence, thus allowing for the automation of tasks that would otherwise necessitate human cognition. Such technology has increasingly demonstrated capacity to outperform humans for functions relating to image recognition. Given the current lack of cost-effective confirmatory testing, accurate diagnosis and subsequent management depend on visual detection of characteristic findings during otoscope examination. The aim of this manuscript is to perform a comprehensive literature review and evaluate the potential application of artificial intelligence for the diagnosis of ear disease from otoscopic image analysis.

A systematic review of remote otological assessment using video-otoscopy over the past 10 years: reliability and applications.

PURPOSE: This systematic review describes and evaluates the current literature on remote otological assessment using video-otoscopy with regards to reliability and potential applications. METHODS: Systematic review was conducted in accordance with the PRISMA statement. There was heterogeneity of included studies, so a descriptive analysis was undertaken. RESULTS: Seventeen studies were included for analysis conducted across a variety of healthcare settings. Overall, there was a trend towards acquisition of adequate images for diagnosis by non-otolaryngology-specialist facilitators with reasonable agreement between asynchronous images and controls; however, there was significant variation between the studies. CONCLUSION: Remote otological assessment using video-otoscopy shows potential as a safe and effective method for detecting the presence of ear disease in a wide range of healthcare settings. Barriers to the acquisition of adequate images include the presence of obstructing cerumen, and strategies to deal with this should be considered. Further work is required to evaluate endoscope-based systems to assess whether they will allow the acquisition of higher quality images.

Objective assessment of autophony during phonation in the diagnosis of patulous Eustachian tube patients.

OBJECTIVE: A system enabling the objective assessment of the transmission of voice sounds to the external auditory canal (EAC) during phonation has recently been revised. Our aim was to evaluate the effectiveness of this new system in the diagnosis of patulous Eustachian tube (PET) patients by comparing the results obtained using this method with those obtained from conventional objective tests to diagnose PET. METHODS: A prospective survey of medical records was included with definite PET, possible PET, and sensorineural hearing loss as control. The measurement system consists of a personal computer, an AD/DA converter (NI 6361, National Instruments), a probe microphone system for recording voice sound (ER-10C, Etymotic Research) and two microphones for measuring noise sound in the EAC (ER-10B+, Etymotic Research). Pronouncing the "Ni" sound for 5 s were recorded with these three microphones. The ratio of the maximum sound pressure of voice sound and noise sound in EAC (EAC/Voice) was simultaneously calculated, and results were displayed on a personal computer for diagnosing. RESULTS: Thirty-one patients of 42 ears with definite PET, 26 patients of 38 ears with possible PET, and 12 patients of 24 ears with sensorineural hearing loss as control were included. The EAC/Voice were 8.63 ± 5.43, 25.41 ± 32.63, and 25.87 ± 24.93 in the control, definite PET, and possible PET group respectively. The control group was significantly different from the definite PET (p < 0.05) and possible PET group (p < 0.05). ROC curve analysis confirmed 14.7 as the best diagnostic cut-off value of EAC/Voice (area under the curve=0.782, 95% CI 0.671-0.894). By adopting this cut-off point, 25 (56.8%) and 22 (61.1%) ears were determined as positive findings in the definite PET and possible PET group, respectively. There was no significant correlation between the positive findings judged by the current method and that of sonotubometry in the control (r = -0.63, p = 0.769), definite PET (r = 0.12, p = 0.451), and possible PET group (r = 0.12, p = 0.451). CONCLUSION: The current system is more useful in the objective assessment of autophony during phonation by calculating the ratio of voice sound and elicited noise sound transmitted in the EAC (EAC/Voice). This method seems promising because it is able to detect cases eluding conventionally used test methods such as sonotubometry performed without phonation, thereby increasing the accuracy of PET diagnoses.

Comprehensive Community Screening of Otological Patients by Trained Technicians Using a Telemedicine Device: An Efficient and Cost-Effective Way to Triage Patients With Ear Diseases.

OBJECTIVE: To emphasize the benefits of tele-otology in community screening of patients with ear diseases. METHODS: A retrospective study of all patients screened and treated under the Shruti tele-otology program between 2013 and 2019 was conducted. It involved screening, diagnosis, medical management, surgical intervention, and rehabilitation using hearing aid. The study focused on underprivileged and underserved community of rural and urban slums across 12 states of India. The study was conducted using a telemedicine device called ENTraview, that is, a camera-enabled android phone integrated with an otoscope and audiometry screening. RESULT: A total of 810 746 people were screened, and incidence of various ear diseases was recorded. Ear problems were found in 265 615 (33%) patients, of which 151 067 (57%) had impacted wax, 46 792(18%) had chronic suppurative otitis media, 27 875 (10%) had diminished hearing, 12 729 (5%) had acute otitis media and acute suppurative otitis media (ASOM), and 27 152 (10%) had problems of foreign body, otomycosis, and so on. Of the total 265 615 referred patients, 20 986 (8%) reported for treatment and received treatment at a significantly reduced cost through Shruti program partners. The conversion rate of nonsurgical and surgical procedure was also compared, and it was found that, while 9% of the patients opted for nonsurgical treatment, only 3% opted for surgery in the intervention group giving a significant P value of .00001. CONCLUSION: The potential for telemedicine to reduce inequalities in health care is immense but remains underutilized. Shruti has largely been able to bridge this gap as it is an innovative, fast, and effective programs that address the ear ailment in the community.

Measuring the health utility of chronic eustachian tube dysfunction.

OBJECTIVE: To assess the health utility of chronic Eustachian tube dysfunction (ETD). METHODS: This is a prospective study of 53 patients with chronic ETD recruited from a tertiary clinic from April 2017 to July 2018. The 7-Item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) was administered, and health utility was evaluated using the EuroQol-5 Dimensions-3 Level Instrument (EQ-5D-3L), the visual analogue scale (VAS), time tradeoff (TTO), and standard gamble (SG). Participants were grouped into medical or procedural management groups. One-week follow-up included repeated health utility measures and ETDQ-7. RESULTS: Fifty-three patients were included in the final analysis. Of those, 34 were managed medically, and 19 received myringotomies ± PE tubes. The mean baseline ETDQ-7 was 4.26 ± 1.31; whereas health utility measures were different depending on the method utilized: EQ-5D-3L 0.90 ± 0.11; VAS 0.76 ± 0.21; TTO 0.85 ± 0.23; and SG 0.94 ± 0.11 (P < .001). There was a significant change in ETDQ-7 (P = .001) and TTO (P = .011) scores posttreatment. On the ETDQ-7, question 2 (pain in the ears) was significantly associated with VAS (P = .032), and question 4 (ear symptoms during a cold or sinusitis) was significantly associated with TTO (P = .006). CONCLUSION: Chronic ETD has a significant burden on quality of life, with a health utility similar to gastroesophageal reflux disease and moderate asthma. Although treatment-related changes are measurable using disease-specific quality-of-life measures, only TTO was significantly changed after treatment. Health utility seemed to depend on the method of measurement but provided a benchmark for evaluating cost-effectiveness of innovations to manage ETD. LEVEL OF EVIDENCE: 2 Laryngoscope, 130:E39-E44, 2020.

CEDRA: A Tool to Help Consumers Assess Risk for Ear Disease.

This article introduces the Consumer Ear Disease Risk Assessment (CEDRA) tool. CEDRA is a brief questionnaire designed to screen for targeted ear diseases. It offers an opportunity for consumers to self-screen for disease before seeking a hearing device and may be used by clinicians to help their patients decide the appropriate path to follow in hearing healthcare. Here we provide highlights of previously published validation in the context of a more thorough description of CEDRA's development and implementation. CEDRA's sensitivity and specificity, using a cut-off score of 4 or higher, was 90% and 72%, respectively, relative to neurotologist diagnoses in the initial training sample used to create the scoring algorithm (n = 246). On a smaller independent test sample (n = 61), CEDRA's sensitivity and specificity were 76% and 80%, respectively. CEDRA has readability levels similar to many other patient-oriented questionnaires in hearing healthcare, and informal reports from pilot CEDRA-providers indicate that the majority of patients can complete it in less than 10 min. As the hearing healthcare landscape changes and provider intercession is no longer mandated, CEDRA provides a measure of safety without creating a barrier to access.

Large-scale otoscopic and audiometric population assessment: A pilot study.

OBJECTIVE: Large-scale otoscopic and audiometric assessment of populations is difficult due to logistic impracticalities, particularly in low- and middle-income countries (LMIC). We report a novel assessment methodology based on training local field workers, advances in audiometric testing equipment and cloud-based technology. METHODS: Prospective observational study in Bohol, Philippines. A U.S. otolaryngologist/audiologist team trained 5 local nurses on all procedures in a didactic and hands-on process. An operating otoscope (Welch-AllynR) was used to clear cerumen and view the tympanic membrane, images of which were recorded using a video otoscope (JedMedR). Subjects underwent tympanometry and distortion product otoacoustic emission (DPOAE) (Path SentieroR), and underwent screening audiometry using noise cancelling headphones and a handheld Android device (HearScreenR). Sound-booth audiometry was reserved for failed subjects. Data were uploaded to a REDCap database. Teenage children previously enrolled in a 2000-2004 Phase 3 pneumococcal conjugate vaccine trial, were the subjects of the trainees. RESULTS: During 4 days of training, 47 Filipino children (M/F = 28/19; mean/median age = 14.6/14.6 years) were the subjects of the trainee nurses. After the training, all nurses could perform all procedures independently. Otoscopic findings by ears included: normal (N = 77), otitis media with effusion (N = 2), myringosclerosis (N = 5), healed perforation (N = 6), perforation (N = 2) and retraction pocket/cholesteatoma (N = 2). Abnormal audiometric findings included: tympanogram (N = 4), DPOAE (N = 4) and screening audiometry (N = 0). CONCLUSION: Training of local nurses has been shown to be robust and this methodology overcomes challenges of distant large-scale population otologic/audiometric assessment.

Feasibility and acceptability of training community health workers in ear and hearing care in Malawi: a cluster randomised controlled trial.

OBJECTIVE: To assess the feasibility and acceptability of training community health workers (CHWs) in ear and hearing care, and their ability to identify patients with ear and hearing disorders. DESIGN: Cluster randomised controlled trial (RCT). SETTING: Health centres in Thyolo district, Malawi. PARTICIPANTS: Ten health centres participated, 5 intervention (29 CHWs) and 5 control (28 CHWs). INTERVENTION: Intervention CHWs received 3 days of training in primary ear and hearing care, while among control CHWs, training was delayed for 6 months. Both groups were given a pretest that assessed knowledge about ear and hearing care, only the intervention group was given the posttest on the third day of training. The intervention group was given 1 month to identify patients with ear and hearing disorders in their communities, and these people were screened for hearing disorders by ear, nose and throat clinical specialists. OUTCOME MEASURES: Primary outcome measure was improvement in knowledge of ear and hearing care among CHWs after the training. Secondary outcome measures were number of patients with ear or hearing disorders identified by CHWs and number recorded at health centres during routine activities, and the perceived feasibility and acceptability of the intervention. RESULTS: The average overall correct answers increased from 55% to 68% (95% CI 65 to 71) in the intervention group (p<0.001). A total of 1739 patients with potential ear and hearing disorders were identified by CHWs and 860 patients attended the screening camps, of whom 400 had hearing loss (73 patients determined through bilateral fail on otoacoustic emissions, 327 patients through audiometry). Where cause could be determined, the most common cause of ear and hearing disorders was chronic suppurative otitis media followed by impacted wax. The intervention was perceived as feasible and acceptable to implement. CONCLUSIONS: Training was effective in improving the knowledge of CHW in ear and hearing care in Malawi and allowing them to identify patients with ear and hearing disorders. This intervention could be scaled up to other CHWs in low-income and middle-income countries. TRIAL REGISTRATION NUMBER: Pan African Clinical Trial Registry (201705002285194); Results.

Intra- and inter-rater reliability of the modified ENT assessment score (ENTAS 2) in granulomatosis with polyangiitis: a prospective randomised trial.

OBJECTIVES: Ears nose and throat (ENT) involvement is found on a substantial proportion of patients with granulomatosis with polyangiitis (GPA). Structured, reliable ENT assessment is essential in the management of GPA patients. It is the aim of this study to determine the repeatability (intra-rater reliability) and reproducibility (inter-rater reliability) of the ENT Assessment Score (ENTAS 2). METHODS: The ENTAS 2 built the fundament of the prospective randomized trial. Anamnestic, video endoscopic and diagnostic data of 47 patients were used. A single assessor reference was created. GPA/ENT activity and damage were evaluated by three physicians at two time points (T1/T2). GPA/ENT activity was evaluated in dichotomy (yes/no) and grading (none/mild/moderate/high) and GPA/ ENT damage in dichotomy. RESULTS: ENTAS 2 activity evaluations intra-rater reliability was 80.7% (κ=0.56) in dichotomy and 72.8% (κ=0.41) in grading. ENTAS 2 damage evaluations showed 87.8% (κ=0.74) intra-rater reliability. ENTAS 2 activity inter-rater reliability at T1 was 62.2% (κ=0.43) in dichotomy and 51.1% (κ=0.29) in grading, at T2 it was 68.2% (κ=0.48) in dichotomy and 55.32% (κ=0.33) in grading. Inter-rater reliability of ENTAS 2 damage evaluation was 84.4% (κ=0.79) at T1 and 72.5% (κ=0.64) at T2. CONCLUSIONS: ENTAS 2 intra-rater reliability was high in dichotomous and graded GPA/ENT activity and damage evaluations. Inter-rater reliability was high in dichotomous activity and damage evaluations, but low in graded activity evaluations. The data demonstrate that the ENTAS 2 is a reliable score-system considering GPA/ENT activity and damage evaluations.

Sonotubometric Assessment for Severity of Patulous Eustachian Tube.

OBJECTIVE: To investigate the relationship between the morphological patency of the eustachian tube (ET) and sound transmission via the ET. STUDY DESIGN: Retrospective chart review and model experiment. SETTING: Tertiary referral center. SUBJECTS: A total of 56 ears of 28 patients (9 men and 19 women, aged from 12 to 82 yr, mean 40.4 ±â€Š21.5 yr) who underwent sonotubometric measurement using postural change as well as computed tomography (CT) of the ET in the sitting position, including 26 ears with definite patulous ET, 9 ears with possible patulous ET, and 21 ears without patulous ET. METHOD: Commercial equipment for sonotubometry (JK-05A; RION Co., Ltd., Kokubunji, Tokyo, Japan) was used in the following two investigations. Retrospective survey: sound patency of 7 kHz band noise via the ET was assessed by comparison of acoustic transfer function via the ET in the sitting and forward-bending positions. Sound patency via the ET was compared with morphological patency of the ET (cross-sectional area in the narrowest portion) assessed by three-dimensional CT of the ET in the sitting position. Model experiment: effect of the ET caliber on the acoustic transfer function was examined using a simple model constructed with two truncated syringes with silicone barrels and a narrow connecting tube. RESULTS: Sound patency assessed by sonotubometry was well correlated with the cross-sectional area at the narrowest portion of the ET in the sitting position (r = 0.786, p < 0.001). Correlation between the sound patency via the narrow tube and the caliber of the tube was also confirmed by the model experiment. CONCLUSIONS: Sound patency assessed by sonotubometry using 7 kHz band noise could be useful to predict the morphological severity of patulous ET.

Assessment of nasal-noise masking audiometry as a diagnostic test for patulous Eustachian tube.

OBJECTIVE: The primary objective is to assess the validity of nasal-noise masking audiometry (NNMA) as a clinical diagnostic tool in our patient population. STUDY DESIGN: Retrospective case review. SETTING: Tertiary ambulatory referral center. PATIENTS: Patients with patulous Eustachian tube (PET) were identified from referrals to our Eustachian tube disorders clinic primarily with symptoms including autophony, aural fullness, and hearing their own breathing. The healthy subjects had no history of ear disease. INTERVENTION: NNMA was measured in 20 ears of 10 healthy subjects as well as in 42 ears of 21 patients with suspected PET. MAIN OUTCOME MEASURE: NNMA mean auditory thresholds were measured at frequencies ranging from 250 to 8,000 Hz. RESULTS: When stratified as definitive or probable PET based on observed tympanic membrane movement with breathing, both Definitive and Probable PET groups had significantly higher NNMA mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.003), 1,000 Hz (p = 0.019, p = 0.001), and 6,000 Hz (p = 0.4, p = 0.001). When stratified based on symptoms on the day of testing, both Symptomatic Ears and Non-Symptomatic Ears had significantly higher mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.015) and at 1,000 Hz (p = 0.002, p = 0.004). CONCLUSION: Our results demonstrate a larger masking effect in patients with PET compared to normal subjects in the low-frequency region. In clinical practice, the relatively small effect and the wide variability of results between patients have made this test be of little value clinically in our patient population.

Comparison of different computed tomography post-processing modalities in assessment of various middle ear disorders.

Several anatomic structures of the middle ear are not optimally depicted in the standard axial and coronal planes. Several 2D and 3D image-processing modalities are currently available for CT examinations in clinical radiology departments. Till now 3D reconstructions of the temporal bone have not been widely used yet, and attracted only academic interest. The aim of this study was to compare axial (source images), 2D and 3DCT post-processing modalities, and to evaluate the value of 3D reconstructed images/virtual endoscopy (VE) in assessment of various middle ear disorders for identification of the best modality/view for assessment of a particular middle ear structure or pathology. 40 patients with various middle ear disorders, planned for surgical intervention were included in prospective study. Multi-slice CT was performed for all patients. Scans were acquired in the axial plane. The axial source datasets were utilized for generation of 2D reformations and 3D reconstructed images. All studied images were divided into three categories: axial (source images), 2D reformations (MPR and sliding-thin-slab MIP) and 3D reconstruction (virtual endoscopy). The visibility of middle ear structures and pathologies with each modality were scored qualitatively using three-point scoring system in reference to operative findings. Stapes superstructure and footplate, incudostapedial joint, oval and round windows, tympanic segment of the facial nerve and tegmen were not optimally depicted in the axial plane. Sinus tympani and facial recess were best visualized with axial images or VE. 3D reconstruction/VE allowed good visualization of all parts of ossicular chain except stapes superstructure. Regarding pathologic changes, 2D reformations and 3D reconstructed images allowed better visualization of erosion of ossicles and tegmen. 3D reconstruction/VE did not allow detection of foci of otospongiosis. 2D reformations can be considered the mainstay in assessment of most middle ear structures and pathologies. 3D reconstruction/VE seems to provide a useful method for a preoperative general overview of the middle ear anatomy, particularly for the ossicular chain, round window and retrotympanum.

Multiwavelength fluorescence otoscope for video-rate chemical imaging of middle ear pathology.

A common motif in otolaryngology is the lack of certainty regarding diagnosis for middle ear conditions, resulting in many patients being overtreated under the worst-case assumption. Although pneumatic otoscopy and adjunctive tests offer additional information, white light otoscopy has been the main tool for diagnosis of external auditory canal and middle ear pathologies for over a century. In middle ear pathologies, the inability to avail high-resolution structural and/or molecular imaging is particularly glaring, leading to a complicated and erratic decision analysis. Here, we propose a novel multiwavelength fluorescence-based video-rate imaging strategy that combines readily available optical elements and software components to create a novel otoscopic device. This modified otoscope enables low-cost, detailed and objective diagnosis of common middle ear pathological conditions. Using the detection of congenital cholesteatoma as a specific example, we demonstrate the feasibility of fluorescence imaging to differentiate this proliferative lesion from uninvolved middle ear tissue based on the characteristic autofluorescence signals. Availability of real-time, wide-field chemical information should enable more complete removal of cholesteatoma, allowing for better hearing preservation and substantially reducing the well-documented risks, costs and psychological effects of repeated surgical procedures.

Presentation and initial assessment of ENT problems in patients with granulomatosis with polyangiitis (Wegener's).

BACKGROUND: Granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) is a primary systemic vasculitis that affects medium to small sized vessels throughout the body. It often presents with symptoms and signs involving the ear, nose, and head and neck area. OBJECTIVE: To highlight salient features of ENT-related issues in granulomatosis with polyangiitis, and raise awareness of the condition. METHODS: A case report of a patient with limited disease and an insidious onset is presented, along with a review of the current literature. In addition, basic initial management is described. RESULTS: Eighty-six publications were used to describe salient features of ENT-related issues in granulomatosis with polyangiitis. CONCLUSION: The time to diagnosis has not reduced significantly in the last 10 years in the UK. A high index of suspicion is required for an earlier diagnosis of granulomatosis with polyangiitis.

Contribution of Vestibular-Evoked Myogenic Potential (VEMP) testing in the assessment and the differential diagnosis of otosclerosis.

BACKGROUND: The aim of this prospective clinical study was to evaluate the clinical importance of Vestibular-Evoked Myogenic Potentials (VEMPs) in the assessment and differential diagnosis of otosclerosis and otologic diseases characterized by "pseudo-conductive" components. We also investigated the clinical appearance of balance disorders in patients with otosclerosis by correlating VEMP results with the findings of caloric testing and pure tone audiometry(PTA). MATERIAL AND METHODS: Air-conducted(AC) 4-PTA, bone-conducted(BC) 4-PTA, air-bone Gap(ABG), AC, BC tone burst evoked VEMP, and calorics were measured preoperatively in 126 otosclerotic ears. RESULTS: The response rate of the AC-VEMPs and BC-VEMPs was 29.36% and 44.03%, respectively. Statistical differences were found between the means of ABG, AC 4-PTA, and BC 4-PTA in the otosclerotic ears in relation to AC-VEMP elicitability. About one-third of patients presented with disequilibrium. A statistically significant interaction was found between calorics and dizziness in relation to PTA thresholds. No relationship was found between calorics and dizziness with VEMPs responses. CONCLUSIONS: AC and BC VEMPs can be elicited in ears with otosclerosis. AC-VEMP is more vulnerable to conductive hearing loss. Evaluation of AC-VEMP thresholds can be added in the diagnostic work-up of otosclerosis in case of doubt, enhancing differential diagnosis in patients with air-bone gaps. Otosclerosis is not a cause of canal paresis or vertigo.