Rapid Evaluation of Pulsatile Tinnitus Using Ambient Pressure Tympanography: A Case Series.

Background: Pulsatile tinnitus (PT) is a form of tinnitus described as a rhythmic beating or whooshingin 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 temporalbone that may cause PT. APT measures compliance of the tympanic membrane (TM) over the span of15-60 s with ambient pressure in the ear canal. The reflex decay test protocol includes APT to measurechanges in admittance with a tonal stimulus. Using a contralateral reflex decay test setup withoutthe use of a contralateral stimulus (outside of the ear at 75 dB), any movement of the tympanic membranemay be considered internally produced.
Research Design: When a patient experiences tinnitus that is nonpulsatile, contralateral reflex decay testingwithout the stimulus tone should reveal a flat-line recording because there is no change in pressure orvolume of the middle ear space caused by the stimulus. When a patient experiences PT, the TM mayappear 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 audiologyand 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 keptoutside of the patient's ear canal to avoid stimulating the system. The measuring probe tip was inserted in thesymptomatic 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 arhythmic pattern that corresponded with the heartbeat. Imaging studies that were performed for eachpatient demonstrated the likely cause of PT.
Conclusion: APT is an efficient clinical tool used to evaluate PT. If a rhythmic change in admittancethat corresponds with the patient's heart rate is noted, then further imaging of the temporal bone todetermine possible causes may be warranted.