Video Ocular Counter-Roll (vOCR): Otolith-Ocular Function and Compensatory Effect of the Neck Following Vestibular Loss

Predictors of Chronic Dizziness in Acute Unilateral Vestibulopathy: A Longitudinal Prospective Cohort Study

OBJECTIVE

Chronic dizziness after acute unilateral vestibulopathy (AUVP) causes significant social and economic burdens. This study aims to identify predictors of chronic dizziness.

STUDY DESIGN

Prospective, longitudinal cohort study.

SETTING

ENT departments from secondary and tertiary hospitals.

METHODS

Participants meeting the Barany Society's diagnostic criteria for AUVP were included. Evaluations occurred within 0 to 21 days (T1), and at 4 (T2) and 10 weeks (T3) postonset. The primary outcome measure was the Dizziness Handicap Inventory (DHI) at 6 months, with a score >30 indicating chronic dizziness. Five clusters of predictors were assessed at T1-3: central vestibular compensation, visual dependence, movement exposure, psychological factors, and balance performance. Separate linear regression models for T1, T2, and T3 were constructed to explain the variability in the 6-month DHI score. Receiver operating characteristics analyses were conducted to predict chronic dizziness.

RESULTS

From June 2021 to January 2024, 103 participants (55.2 ± 16.6 years old, 49 women) were included. The regression models explained the variability in the 6-month DHI score by 33.0% at T1, 47.6% at T2, and 64.0% at T3 (P < .001), including psychological factors (T1, T2, T3), visual dependence (T2, T3), and static balance performance (T3). Cutoff values for the Vestibular Activities Avoidance Instrument (23/54), Visual Vertigo Analog Scale (33.5/100), and Hospital Anxiety and Depression Scale-Anxiety (7.5/21) at 10 weeks postonset predicted chronic dizziness.

CONCLUSION

Higher psychological burden, increased visual dependence, and poorer static balance performance were associated with chronic dizziness. Cutoff values were determined to identify individuals with AUVP at risk for chronic dizziness.

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.

Focused Update on Clinical Testing of Otolith Organs

Sensing gravity through the otolith receptors is crucial for bipedal stability and gait. The overall contribution of the otolith organs to eye movements, postural control, and perceptual functions is the basis for clinical testing of otolith function. With such a wide range of contributions, it is important to recognize that the functional outcomes of these tests may vary depending on the specific method employed to stimulate the hair cells. In this article, we review common methods used for clinical evaluation of otolith function and discuss how different aspects of physiology may affect the functional measurements in these tests. We compare the properties and performance of various clinical tests with an emphasis on the newly developed video ocular counter roll (vOCR), measurement of ocular torsion on fundus photography, and subjective visual vertical or horizontal (SVV/SVH) testing.

When, where, and why should we look for vestibular dysfunction in people with diabetes mellitus?

The biochemistry of diabetes mellitus results in multi-system tissue compromise that reduces functional mobility and interferes with disease management. Sensory system compromise, such as peripheral neuropathy and retinopathy, are specific examples of tissue compromise detrimental to functional mobility. There is lack of clarity regarding if, when, and where parallel changes in the peripheral vestibular system, an additional essential sensory system for functional mobility, occur as a result of diabetes. Given the systemic nature of diabetes and the plasticity of the vestibular system, there is even less clarity regarding if potential vestibular system changes impact functional mobility in a meaningful fashion. This commentary will provide insight as to when we should employ diagnostic vestibular function tests in people with diabetes, where in the periphery we should look, and why testing may or may not matter. The commentary concludes with recommendations for future research and clinical care.

Video ocular counter roll: A bedside test of otolith-ocular function

Here we review the clinical value of a video-oculography test for clinical evaluation of vestibular otolith function. This test is known as the video ocular counter roll (vOCR) and is based on measurement of torsional vestibulo-ocular reflex with a lateral head tilt. The vOCR test consists of a simple maneuver during which the head and torso are tilted en bloc by the examiner. The pattern of vOCR deficit among patients highlights its clinical value in identifying the stage of vestibular loss and recovery. The quick application of vOCR allows examination of otolith-ocular function and assessment of vestibular recovery at the bedside.