Virtual reality for the measurement of SVV and SVH during static head tilt in healthy adults: a novel vestibular test

Background and objective Few previous studies have used virtual-reality (VR) technology to measure subjective visual vertical (SVV) and subjective visual horizontal (SVH) during static head tilt (0 degrees, 30 degrees, 45 degrees, 60 degrees and 90 degrees). We propose a novel vestibular test for measuring the normal range of SVV and SVH during static head tilt in healthy adults. Methods Eighty healthy adults were included in the study. SVV and SVH were calculated in nine head positions. Results With head tilt 90 degrees to the right, SVV skewed to the right, and SVH skewed upward. With head tilt 90 degrees to the left, SVV skewed to the left, and SVH skewed downward. SVV was asymmetrical only at a head tilt of 90 degrees. SVV and SVH were similar at all degrees of head tilt, except for 30 degrees to the right, 45 degrees to the left, and 0 degrees. Conclusions VR measurements showed that SVV and SVH differed at various degrees of static head tilt. The standardized protocol proposed here may be used to establish a reference range for utricle function when evaluating acute, unilateral vestibular lesions.