Evaluation of vestibular function in normal hearing adults with and without tinnitus

Abstract

Tinnitus may occur in individuals with normal hearing and has increasingly been associated with subclinical vestibular dysfunction. The close anatomical relationship between the auditory and vestibular systems suggests that vestibular abnormalities may contribute to tinnitus pathophysiology. To assess vestibular function in normal-hearing adults with and without tinnitus using the Video Head Impulse Test (vHIT). This observational study included 30 participants with tinnitus and 30 without tinnitus. All participants underwent otoscopic examination, pure-tone audiometry, and vHIT assessment. The tinnitus group additionally completed the Tinnitus Handicap Inventory (THI). Vestibular function was evaluated using vestibulo-ocular reflex (VOR) gain and asymmetry ratios across all six semicircular canals. The majority of tinnitus participants demonstrated mild tinnitus severity (70%), with a mean THI score of 25.47 ± 10.54. Significant reductions in LARP-LA and LARP-RP vestibulo-ocular reflex gains, together with increased LARP asymmetry ratios, were observed in the tinnitus group (p < 0.05). No significant differences were found in lateral canal gains, RALP gains, or the remaining asymmetry measures. Weak negative correlations were observed between THI scores and vestibular gain parameters, whereas weak positive correlations were found with vestibular asymmetry ratios. The reduced LARP canal gains suggest selective subclinical vestibular involvement in tinnitus despite normal hearing sensitivity and absence of overt vestibular symptoms. These findings support the hypothesis that tinnitus may involve vestibular and central neural mechanisms in addition to auditory dysfunction. Tinnitus in normal-hearing adults may be associated with subtle vestibular dysfunction, particularly involving the LARP canal pair.