Analysis Of Unilateral Tinnitus And Spatial Relationship Between Acoustic Nerve And Peripheral Vessels

Objective Tinnitus is the perception of sound in the absence of a corresponding external acoustic stimulus. The causes vary, and the pathogeneses are still unclear in most cases. Neurovascular compression is one reason of tinnitus. At present, the study of tinnitus and spatial relationship between acoustic nerve and peripheral vessels is little. This research, based on patients of unilateral tinnitus without clear etiology who had been evaluated by internal auditory canal (IAC) MRI, will study on sex, age, course of tinnitus, the relationship with hearing loss, and the spatial relationship between vestibulocochlear nerve (â…§ cranial nerve, or â…§ CN) and peripheral vessels with tinnitus, analyzing the clinical and imaging feature, in order to explore plausible imaging characteristics of tinnitus induced by neurovascular compression.Method In this study, collected from January2012to December2012, ENT department of the Sir Run Run Shaw Hospital,59outpatients of unilateral tinnitus without clear etiology who had been evaluated by internal auditory canal MRI and excluded by history of prior ear disease, clinical data were retrospectively analyzed. The chi-square test is adopted to analyze the location and pattern of the contact between acoustic nerve and peripheral vessels with tinnitus.Result Of59cases studied, age distribution from23years to82years, average age of46.6years,30(50.8%) were male patients,29(49.2%) were female patients, the sex ratio of men to women approximately was1:1,30(50.8%) were associated with the onset of the right ear,29(49.2%) were left,22(37.3%) were the duration of no less than1year,21were less than1year but no less than3months,16were less than3months,5(8.5%) were pulsatile tinnitus,54(91.5%) were nonpulsatile,29(49.2%) were low-pitch tinnitus,30(50.8%) were high-pitch,18(30.5%) were persistent tinnitus, and41(69.5%) were paroxysmal. A significant ipsilateral sensorineural hearing loss can be obtained (P<0.01). As for the vascular loops in IAC, or the orientation (medial, lateral, superior, or inferior surface of VIII CN), location (the locus approaching IAC or brain stem), or pattern (perpendicular or not) of contact between vessels and â…§ CN in cistern, significances cannot be obtained (P>0.05), comparing affected side to the unaffected one.Conclusion The prevalence of unilateral tinnitus without clear etiology in sex and laterality is similar. Tinnitus is linked to the ipsilateral sensorineural hearing loss. However, unilateral tinnitus is not associated with spatial relationship between acoustic nerve and peripheral vessels.