Analyzing eustachian tube function in patients with symptoms of chronical Eustachian tube dysfunction by pressure chamber measurements.

Abstract

The determination of Eustachian tube dysfunction (ETD) subtypes in daily routines is based on symptoms of the patient, otoscopy, nasopharyngoscopy, tympanometry, pure tone audiometry, and Valsalva's test, even though this clinical assessment is often not sufficient to clearly diagnose the subtype. In the study, we have evaluated the possibility of the determination of different subtypes of ETD by pressure chamber measurements. In a single-person pressure chamber, we exposed 17 patients to pressure increases and decreases. The pressure profile of the continuous impedance of each tympanic membrane during the 5-min lasting measurement and the Eustachian tube (ET) pressure equilibration function reflecting parameters-ET opening pressure (ETOP), ET opening duration (ETOD), ET closing pressure (ETCP), and ET opening frequency (ETOF)-were documented and analyzed. By interpretation of the pattern of the continuous impedance of the tympanic membrane, we could relate patients to a subtype of ETD. Clearly identified by pressure chamber-based measurements could be patients with patulous ETD (n = 2) and baro-challenged-induced ETD (n = 4). The remaining 11 patients were classified as ETD not further classified. Patients diagnosed as patulous ETD did not show a pressure response on the tympanic membrane during the phases of pressure increase and decrease. In patients with baro-challenged-induced ETD, the measurement had to be interrupted due to the development of otalgia during progressive pressure increase as a result of insufficient possibility to equalize pressure variations. Pressure chamber-based measurements enable an objective and safe dynamic testing of the ET pressure equalization function in patients with ETD. In addition, via continuous impedance measurement, it is possible to identify patients with patulous ETD and baro-challenge-induced ETD. These results are a relevant preliminary work to identify and assess patients for different therapy options.