Subjective visual vertical during eccentric rotation in patients with vestibular neuritis

The subjective visual vertical (SVV) is a useful tool to evaluate clinical manifestations of vestibular loss, but there have been normal variations of the SVV within 1 degrees -3 degrees , and over time, the absolute deviated degrees of SVV tilts decreases. We investigated SVV values in patients with vestibular neuritis (VN) during eccentric rotation, the method used to assess utricular function during stimulation of one labyrinth. And we performed SVV in the resting state and during eccentric rotation to the lesion side and the healthy side of 15 patients with VN and 20 normal subjects. No difference in the resting state SVV values was observed between the VN patients and the control group, but there were significant differences in SVV values between these two groups during eccentric rotation. Therefore, SVV during eccentric rotation allowed us to obtain information about unilateral vestibular loss that could not be found by conventional SVV in patients with VN. Thus, SVV during eccentric rotation might be a good tool to diagnose unilateral vestibular loss.