Abstract
Background: Pulsatile tinnitus (PT) is a form of tinnitus described as a rhythmic beating or whooshing in the ear or ears. Causes of PT can be quite variable and difficult to assess. Purpose: Ambient pressure tympanography (APT) can aid in diagnosing the pathology of the temporal bone that may cause PT. APT measures compliance of the tympanic membrane (TM) over the span of 15-60 s with ambient pressure in the ear canal. The reflex decay test protocol includes APT to measure changes in admittance with a tonal stimulus. Using a contralateral reflex decay test setup without the use of a contralateral stimulus (outside of the ear at 75 dB), any movement of the tympanic membrane may be considered internally produced. Research Design: When a patient experiences tinnitus that is nonpulsatile, contralateral reflex decay testing without the stimulus tone should reveal a flat-line recording because there is no change in pressure or volume of the middle ear space caused by the stimulus. When a patient experiences PT, the TM may appear to be moving rhythmically secondary to pressure and volume changes in the middle ear space. Study Sample: Three adult patients (age older than 18 years) who recently presented to an audiology and otolaryngology clinic and reported PT symptoms were evaluated using APT. Intervention: Interventions were not studied during this case series. Data Collection and Analysis: GSI TympStar Pro Equipment measured TM movement over 15-s intervals. Contralateral reflex decay test settings were utilized with the contralateral stimulus reduced to 75 dB and kept outside of the patient's ear canal to avoid stimulating the system. The measuring probe tip was inserted in the symptomatic ear canal to maintain pressure and observe any internal movement in the middle ear. Results: APT of our patient cohort revealed fluctuating changes in the middle ear cavity volume with a rhythmic pattern that corresponded with the heartbeat. Imaging studies that were performed for each patient demonstrated the likely cause of PT. Conclusion: APT is an efficient clinical tool used to evaluate PT. If a rhythmic change in admittance that corresponds with the patient's heart rate is noted, then further imaging of the temporal bone to determine possible causes may be warranted.