Middle ear dynamic characteristics in patients with otosclerosis

OBJECTIVE: To investigate the middle ear dynamic characteristics in patients with otosclerosis using the sweep frequency impedance meter (SFI test) and conventional tympanometry, and also to evaluate the diagnostic efficiency of the SFI test for otosclerosis. DESIGN: The study was designed to collect a total of 25 (36 ears) consecutive patients with otosclerosis. All subjects followed a clinical protocol, which consisted of a hearing problem questionnaire, otoscopic examination, and audiometric measurements. These included pure tone audiometry, conventional tympanometry, and SFI test. RESULTS: In the SFI test, the middle ear dynamic characteristics were measured in terms of the resonance frequency and middle ear mobility. Three distinct categories of middle ear dynamic characteristics were found in patients with otosclerosis, i.e., high stiffness, normal stiffness, and low stiffness middle ear status. On comparison of the results of SFI with conventional tympanometry, a significantly higher percentage of abnormal stiffness was found when using the SFI test than that when using conventional tympanometry. CONCLUSIONS: The present findings confirm the advantage of the SFI test over conventional tympanometry in detecting middle ear status and mechanics in patients with otosclerosis. Moreover, different middle ear dynamic characteristics in patients with otosclerosis are most likely to be related to the different stages of the pathological changes.