Volume 65, Issue 4 (3 2007)                   Tehran Univ Med J 2007, 65(4): 24-31 | Back to browse issues page

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Abstract:   (8262 Views)
Background: Sudden sensorinueural hearing loss (SSNHL) is a baffling condition for patients, and its etiology, audiologic characteristics, prognostic factors, and treatment are still controversial.
Methods: In this prospective study, we performed pure tone audiometry (PTA), impedance acoustics (IA), auditory brainstem responses (ABR), otoacoustic emissions (OAE), and transiently evoked otoacoustic emissions (TEOAE) before beginning treatment for 53 patients with SSNHL. We then entered each patient, randomly and alternately, in one of two treatment groups: oral steroids + acyclovir vs. intravenous urographin.
Results: In 22 (41.5%) of the 53 patients (22 female, 31 male), we found negative or no signal to noise ratio and overall correlation in TEOAE. Furthermore, 26 cases (49%) had positive overall correlations less than 50%, and five cases (4.4%) had overall correlations >50%. Although 15 cases (28.3%) responded well, 20 cases (37.7%) showed only a partial response, and 18 cases (33.9%) had poor or no response to our treatment. The mean value for overall correlation in the three subgroups of patients (no response, partial response, and complete response) was -3.5% (±1/16%), + 11% (±1.99%), and +36.6% (±3.07%) respectively (P = 0.01). From 52 cases, 20 had no reproducible wave in ABR (38.5%), three cases had abnormal ABR with normal OAE, all of which responded completely to treatments. Thirteen cases had abnormal ABR and OAE, none of which responded to treatment, and six cases had normal ABR with abnormal OAE, which often responded to treatment.
Conclusions: ABR and OAE may be useful in the diagnosis of SSNHL and determining the site of such lesions as ischemia or neuropathy. The overall correlation (and S/N ratio) in TEOAE is a valuable prognostic factor in SSNHL.
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