Ambient pressure tympanometry (APT) had low sensitivity and specificity in detecting radiologic correlates of subjective pulsatile tinnitus, suggesting it may not reliably determine which patients warrant imaging.
Investigators conducted a single-center retrospective review of 107 adults with subjective pulsatile tinnitus who underwent APT between December 2021 and May 2025 at a tertiary care clinic. Patients were identified through electronic medical records and were required to have complete audiometric testing, including pure-tone audiometry, tympanometry, and APT. Two audiologists blinded to patient identity and diagnosis independently reviewed the APT tracings and classified their waveform patterns, with disagreements resolved through discussion.
The primary outcomes were the sensitivity and specificity of APT in detecting the source of subjective pulsatile tinnitus, with a positive radiologic correlate and a surgeon-defined diagnosis evaluated as separate reference standards. The investigators also assessed positive predictive value (PPV) and negative predictive value (NPV) and repeated the analyses in a subgroup of 86 patients for whom pulsatile tinnitus was the primary complaint.
Imaging was performed in 137 ears, of which 51 had a radiologic correlate. Among ears with a positive imaging finding, 26 had a pulse-synchronous APT waveform. APT had 51% sensitivity and 57% specificity for detecting any radiologic correlate, with a PPV of 41% and NPV of 66%.
Screening performance remained limited when surgeon diagnoses were used as the reference standard. Surgeons provided a diagnosis for 44% of (n = 65/147) the ears, and 28 of those ears had a pulse-synchronous APT waveform. APT had 43% sensitivity and 55% specificity against surgeon diagnoses, with PPV and NPV of 43% and 55%, respectively.
Restricting the analysis to patients for whom pulsatile tinnitus was the primary complaint produced similar findings. Imaging was available for 108 ears, and a radiologic correlate was identified in 49. APT had 57% sensitivity and 54% specificity for a radiologic correlate. Against surgeon diagnoses, sensitivity was 44% and specificity was 54%. The similarity to the full-cohort results suggested that including patients with secondary pulsatile tinnitus complaints did not meaningfully alter APT screening performance.
Radiologic interpretations and surgeon diagnoses did not always agree. Among 86 ears without an identified radiologic correlate, 23 nevertheless received a surgeon diagnosis, 17 of which were attributed to sources that could not be identified through imaging, including middle ear myoclonus, patulous Eustachian tube dysfunction, sensorineural hearing loss, obstructive Eustachian tube dysfunction, and bruxism. Such discrepancies highlighted limitations in using radiologic findings alone as the diagnostic reference standard.
The study was limited by its retrospective, single-center design. APT tracings were collected over a short interval of 20 seconds, which may have contributed to false-negative results, and testing by multiple audiologists introduced potential performance variation. The criteria used to classify pulse-synchronous tracings also may have increased false-negative classifications. Objective pulsatile tinnitus was not systematically recorded, and imaging protocols, image quality, and interpretations varied across the cohort, limiting the consistency of radiologic findings as a reference standard.
“Clinicians should be encouraged to pursue imaging regardless of a negative APT tracing,” wrote lead study author Christian Bernard, of the Department of Otolaryngology–Head and Neck Surgery at Mayo Clinic Florida, and colleagues.
The study authors reported no conflicts of interest.
Source: Otology & Neurotology Open