Video Head Impulse Test Can Reveal Silent Vestibular Dysfunction in Normal-Hearing Individuals With Tinnitus

Tinnitus may be an early indication of cochleovestibular pathology in individuals with normal hearing. The present study characterizes the Head Impulse Paradigm (HIMP) and the Suppression Head Impulse Paradigm (SHIMP) among normal-hearing individuals with tinnitus.

Forty-five normal-hearing individuals with unilateral tinnitus and 45 normal-hearing individuals without tinnitus underwent both the HIMP and the SHIMP. The vestibulo-ocular reflex (VOR) gains in the HIMP and SHIMP, interaural VOR gain asymmetry, and the presence/absence of compensatory saccades in the HIMP and anticompensatory saccades in the SHIMP were measured for all participants.

Significant reductions in both HIMP and SHIMP VOR gains were recorded among the normal-hearing individuals with tinnitus, exclusively in the ears presenting with tinnitus compared with their nontinnitus ears (p < .05) and their healthy counterparts (p < .05). The interaural gain asymmetry in both the HIMP and the SHIMP was significantly higher among the normal-hearing individuals with tinnitus (p < .05). Moreover, individuals with tinnitus exhibited various patterns of anticompensatory saccades that were distinct from those of healthy individuals. The study also found a negative correlation between the duration of tinnitus and the VOR gain values in both the HIMP and the SHIMP (p < .05).

The findings indicate that the VOR and its suppression mechanism are affected among normal-hearing individuals with tinnitus. Reduced VOR gains and altered saccadic patterns on the HIMP and SHIMP suggest subtle peripheral vestibular involvement in these individuals. The results of the study highlight the potential utility of video head impulse test paradigms in identifying subclinical vestibular deficits in normal-hearing individuals with tinnitus.