Investigation of Video Ocular Counter-Roll Findings According to Head and Body Tilt Positions in Healthy Subjects.

Objectives: A vestibulo-ocular reflex called the ocular counter-roll can be used to assess how well the otolith organs are functioning. The video ocular counter-roll (vOCR) test is a recent addition to the videonystagmography test battery that allows for video recording and quantitative ocular counter-roll analysis. The purpose of this study is to investigate potential discrepancies in vOCR measurements obtained from a 30° lateral head tilt in the roll plane versus measurements obtained from a 30° tilt of the head and body.

Design: Thirty otologically, and neurologically healthy subjects aged 18 to 30 (M = 23.32 years, SD = 2.66 years; 8 men, 22 women) participated in this study. Pure-tone audiometry, oculomotor tests, and vOCR evaluation were performed for all participants. The vOCR assessment was performed in 2 positions, 30° lateral head tilt, and 30° body tilt position. The degree of static vOCR eye position and vOCR asymmetry in both positions were calculated and compared.

Results: There was no statistically significant difference between the vOCR findings obtained in the right and left 30° lateral head tilt (p = 0.546) and body tilt (p = 0.114). vOCR asymmetry was determined as median (interquartile range) 0.08 (0.07) in lateral head tilt position and 0.09 (0.06) in body tilt position. The degree of static vOCR (8.75° [1.91]) detected during body tilt was statistically greater than the static vOCR (6.62 [1.69]) detected during head tilt (p < 0.001). There was no statistically significant difference in terms of ocular counter-roll asymmetry detected between head tilt and body tilt (p = 0.918).

Conclusions: Our study shows a significant difference in the vOCR responses during head tilt and body tilt, a finding that should be considered during clinical evaluation of vestibular function. There was no significant asymmetry between the responses with either head or body tilt.