Is There Any Effect of Subjective Tinnitus on Vestibular Evoked Myogenic Potentials

Idiopathic subjective tinnitus has a complex pathophysiology in which not only cochlear and central classical auditory pathways but also nonclassical auditory pathways of different parts of the brain are involved. Vestibuloocular and vestibulocollic pathways are the central projections of utricle and saccule used in the vestibular evoked myogenic potential (VEMP) test. Aim of this study was to investigate the effects of idiopathic subjective tinnitus on vestibuloocular and vestibulocollic pathways via VEMP. We prospectively analyzed 30 unilateral idiopathic subjective tinnitus patient's cervical, ocular VEMP tests, tinnitus handicap index scores, symptom duration and compared with contralateral ear and 35 healthy volunteers. The latencies and amplitudes of P1 and N1 waves were recorded and pathologic wave criteria was calculated according to healthy volunteer's data. In cervical VEMP there were significant longer latencies of P1 and N1 waves with respect to contralateral ear and control group. In ocular VEMP test, N1 and P1 latencies and amplitudes were not significantly different. The percentages of pathologic wave of the tinnitus side were not significantly higher in both cervical VEMP and ocular VEMP tests with respect to contralateral side. Tinnitus handicap index scores and symptom duration had no relationship with latency and amplitude of VEMP tests. Although cervical VEMP P1 and N1 latencies were significantly longer, subjective tinnitus did not result in pathological alterations in the VEMP test. Presence of subjective tinnitus is not an influencing factor in the VEMP interpretation.