Evaluation of hearing with audiometry,multifrequency tympanometry and transient evoked otoacoustic emission tests in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease that etiology is yet known, especially effect spine and sacroiliac joints, also may be accompanied the clinical findings due to the involvement of organs such as eye, heart, lung, kidney and intestine. The aim of our work was to examine middle ear, inner ear and efferent auditory system by using multifrequency tympanometry, transient evoked otoacoustic emission (TEOAE) and contralateral suppression test in detail. A total of 69 subjects; 33 patients with AS and 36 healthy subjects participated in the study. Immitansmetric measurements of participants were performed, and then their hearing levels were measured applying pure tone audiometry. The evaluation of each group with otoacoustic emission test was performed in two stages: before giving contralateral acoustic stimulation (CAS) and during 70 dB narrow band contralateral acoustic stimulation. Mean age of patients with ankylosing spondylitis was 41,58±7,7, mean age of control group was 38,19±8,7 and the difference between groups was not statistically significant (p=0,086). By comparison pure tone hearing levels between ankylosing spondylitis and control group at 125Hz-16000 Hz frequency, pure tone hearing levels of AS patients at all frequencies were higher. These differences were found statistically significant except 2000 Hz, 4000 Hz and 10000 Hz in right ear, 2000 Hz and 10000 Hz in left ear (p<0,05). Tympanogram results in all of the subjects were within normal limits. The value of the resonant frequency of the patient and control group were respectively for right ear 874,24±183,76; 856,94±106,33, for left ear 896±152,55; 65,28±121,78 Hz. The difference was not statistically significant (p>0,05). When compared two groups' TEOAE results, emission results received from ankylosing spondylitis patients were statistically significantly lower than control group at 1000Hz, 2000Hz and 4000Hz frequencies by using otoacoustic emission test (p<0,05). When TEOAE measurement before and during contralateral acoustic stimulation (CAS) were compared to evaluate the contralateral suppression level, it was detected that there was decline in emission values at all frequencies in study group and all frequencies except 4000 Hz in control group (p<0,001). There was no statistically significant difference between contralateral suppression levels in both groups (p>0,05). As a result, our findings indicate that inner ear in ankylosing spondylitis may be target organ. When the ankylosing spondylitis is diagnosed, the patients should be undergo audiologic evaluation and informed about possible pathological involvement. Future studies should continue about middle and inner ear condition in ankylosing spondylitis patients and potential interactions that may be associated with disease characteristics. Key words: Ankylosing Spondylitis, audiometry, transient evoked otoacoustic emission (TEOAE), multifrequency tympanometry.