Subjective visual vertical in different peripheral vestibular disorders

Mostafa El Khosht Mahmoud, Maha Hassan Abou-Elew, Rasha Soliman, Aliaa Aly Moustafa El Brequi

Indian Journal of Otology 2018 24(3):162-167

Context: The subjective visual vertical (SVV) is considered to be a functional measure of otolith-mediated verticality perception. Aims: This study aims to detect the normative data of SVV and to analyze SVV changes in peripheral vestibular disorders. Settings and Design: This was a observational, cross-sectional study. Subjects and Methods: Forty-five adult patients with chronic peripheral vestibular disorders endolymphatic hydrops, vestibular neuritis, and benign paroxysmal positional vertigo and 20 normal individuals were included in this study. After full history taken, SVV deviations and caloric tests were completed. Statistical Analysis Used: Independent Student's t-test for independent sample when comparing 2 groups. ANOVAs test compared three or more means for statistical significance. Tukey's test compared the means of every treatment to the means of every other treatment. Chi-square test was performed. Normal cutoff value was calculated by mean +2 standard deviation (SD) as high limit and mean −2 SD as low limit. Results: The normative data of SVV ranged from −0.2° to 1.26° in clockwise direction and from −0.04° to 0.95° in the counterclockwise direction. SVV in counterclockwise direction were significantly deviated among the three groups of Peripheral vestibular disorder (PVD) patients when compared with controls. It revealed a significant deviation in counterclockwise tilt between left diseased ears in relation to controls. Conclusions: Normal adults displayed a narrow range of one-degree SVV deviation (1.06° and 0.91°) in clockwise and counterclockwise direction, respectively. The three vestibular disorders significantly deviate the SVV in counterclockwise direction compared to control with no gender difference. SVV test alone cannot differentiate between different PVD.

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