Ambient Pressure Tympanometry Wave Patterns in Patients With Superior Semicircular Canal Dehiscence

Abstract

Superior semicircular canal dehiscence (SSCD) is a treatable condition, but current diagnostic modalities have numerous limitations. Clinicians would benefit from an additional tool for diagnostic workup that is both rapid and widely available. Objective: To assess the utility of ambient pressure tympanometry (APT) in the diagnostic workup of SSCD by determining the sensitivity and specificity of APT for SSCD in comparison to other diagnostic modalities. Design: Retrospective cohort study of patients who underwent APT and temporal bone computerized tomography (CT) scans from May 2017 to July 2018. Setting: Tertiary referral center. Participants: APT was performed as part of routine audiological testing on adult patients. We retrospectively analyzed all patients who received both APT and temporal bone CT scans, and divided ears into SSCD and non-SSCD groups based on the presence or absence of radiographic SSCD. Ears with other radiographic findings that could affect tympanic membrane compliance were excluded. Exposures: All patients in this study underwent APT and temporal bone CT scans. Some patients also underwent pure tone audiometry and vestibular evoked myogenic potentials (VEMPs). Main Outcomes and Measures: The primary outcome measures were sensitivity, specificity, and risk ratio of APT for SSCD. Secondary outcome measures include sensitivity of VEMPs and supranormal hearing thresholds. Results: We describe 52 patients (70 ears) who underwent APT and CT imaging (mean age 47.1 years, 67.1% female). APT detected SSCD with 66.7% sensitivity and 72.1% specificity. In symptomatic patients, sensitivity was 71.4% and specificity was 75%. VEMPs performed best at detecting SSCD when defining a positive test as oVEMP amplitude >17 µV, with a sensitivity of 68.2%, similar to APT (p > 0.99). The combination of APT and VEMPs increased sensitivity to 88.9%, better than APT alone (p = 0.031) and trending toward better than VEMPs alone (p = 0.063). Conclusions and Relevance: Rhythmic wave patterns on APT are associated with SSCD and may raise suspicion for this condition in conjunction with consistent results on other diagnostic modalities. Although clinical utility requires confirmation in a larger prospective study, APT is a simple, rapid, and widely available tool warranting further study.

Ambient pressure tympanometry in the workup of patulous eustachian tube and neurotologic disorders

“…However, a significant portion of our cohort displayed pulse‐synchronous patterns at rest, and the majority of CT‐imaged ears displayed radiographic findings suggestive of neurotological diagnoses. APT is not clinically applied for these conditions, despite associations with pulse‐synchronous patterns 6,7 . As these conditions can present similarly to PET, pulse‐synchronous waveforms should prompt consideration for temporal bone CT imaging.…”

“…APT is not clinically applied for these conditions, despite associations with pulse-synchronous patterns. 6,7 As these conditions can present similarly to PET, pulse-synchronous waveforms should prompt consideration for temporal bone CT imaging. Further neurotology workup may also be indicated, as radiographic findings can be incidental.…”

“…Ambient pressure tympanometry (APT), an established but infrequently employed test for PET, measures TM compliance over 20 seconds without external pressure changes and can be performed on most versions of standard tympanometry equipment. APT may demonstrate pulse-synchronous waveforms associated with SSCD and other neurotological conditions 6,7 or respiration-synchronous waveforms during respiratory manoeuvres, which are associated with PET. 3,5,8 In this study, we measure the sensitivity and specificity of APT for PET and compare the sensitivity of various respiratory manoeuvres.…”

Usefulness of Cervical Vestibular-Evoked Myogenic Potentials for Diagnosing Patients With Superior Canal Dehiscence Syndrome: A Meta-Analysis

“…After excluding 607 duplicate articles, 408 articles were excluded due to the lack of a relevant of title and abstract. The full text of the remaining 27 articles was evaluated, and 18 studies were excluded due to the inclusion of other interventions or a lack of outcomes (1,(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43). Consequently, nine studies with 721 participants were finally included in the metaanalysis.…”