Hearing Loss at 250 Hz Can Differentiate Between Different Subtypes of Tinnitus: A Retrospective Chart Review

Abstract

Introduction: Patients suffering from tinnitus are a heterogeneous group. Different subtypes may indicate a different pathogenesis. The subgroups need to be identified in order to find effective treatments. Objectives: The aim of this study was to identify the characteristics of unilateral and bilateral tinnitus to differentiate between different subtypes, using history, audiograms and radiographs of the cervical spine. Methods: A retrospective chart review of 95 consecutive patients with tinnitus that persisted for one month or longer was performed. Results: Patients with unilateral tinnitus had a statistically significant lesser hearing from 250 Hz to 1 KHz compared to bilateral tinnitus. There were no statistically significant differences in radiographic measurements between both groups. Multivariate analysis indicated that hearing loss at 250 Hz was the strongest variable associated with the presence of uni-and bilateral tinnitus. In patients with tinnitus, a hearing loss of more than 23 decibels at 250 Hz was characterized by a high prevalence of self-perceived hearing loss (92% of the patients), balance disorders (75% of the patients), vertigo (63% of the patients), and unilateral tinnitus (54% of the patients). Conclusion: Two subgroups of patients with tinnitus suggest two different pathogenesis: otogenic and non-otogenic tinnitus. Hearing loss at 250 Hz of more than 23 decibels could differentiate between the two forms. There was a higher prevalence of unilateral tinnitus in patients with otogenic tinnitus compared to patients with non-otogenic tinnitus.