Age Is a Greater Influence on Small Saccades Than Target Size in Normal Subjects on the Horizontal Video Head Impulse Test

Vestibulo-Ocular Reflex in the Aging Population

Objectives

The aim of this study was to evaluate vestibulo-ocular reflex (VOR) of individuals over 60 years of age who have not been diagnosed with a specific vestibular pathology.

Methods

Bilateral six-semicircular canal video head impulse test (vHIT), Dizziness Handicap Inventory and European Evaluation of Vertigo scales were applied to participants.

Results

In total, 103 participants were included in the study (75 male, 28 female), and the mean age was 69.35 ± 7.41 years. The mean age of 7th decade group was 64.32±3.12 (59 participants; 38 male, 21 female), and the mean age of 8th decade and older group was 76.11±5.93 (44 participants; 37 male, 7 female). No significant differences were found between the VOR gains of the lateral or vertical semicircular canals between the 7th decade and 8th decade and older groups (p>0.05). In the 8th decade and older group, the presence of right lateral semicircular canal corrective saccade and left posterior semicircular canal corrective saccade showed a positively moderate correlation with VOR gains of the same semicircular canals (r=0.455, p=0.002, and r=0.518, p=0.001, respectively). No significant correlation was found between age and VOR gain in the 7th decade group, however, there was a negatively weak correlation between age and left lateral semicircular canal VOR gain (r=-0.366, p=0.017) in the 8th decade and older group.

Conclusion

While assessing the age-related changes in VOR using vHIT, it must be considered that the changes related to aging of the vestibular system begin to emerge in the population over 70 years of age, and corrective saccade findings may be more informative than VOR gains in revealing these changes.

Influence of Age and Cardiovascular Risk Factors in Vestibular Neuritis: Retrospective Cohort Study

To analyze the influence of age and cardiovascular risk factors (CVRFs) in the evolution of vestibular neuritis (VN).

METHODS

Retrospective cohort study. VN-diagnosed patients were included and divided into two groups: those with and without CVRFs. We analyzed the mean vestibular-ocular reflex (VOR) gain, measured through the video head impulse test (vHIT) at the diagnosis and one-year follow-up. We conducted a factorial analysis of variance (ANOVA) to evaluate the effect of age, sex, and CVRFs in the mean VOR gain.

RESULTS

Sixty-three VN-diagnosed patients were included. There were no statistically significant differences in the mean VOR gain between both groups. However, in the subgroup analysis, there were statistically significant differences when comparing the mean VOR gain at the one-year follow-up between the group over 55 years of age 0.77 ± 0.20 and the group under 55 years 0.87 ± 0.15 (p = 0.036). Additionally, the factorial ANOVA demonstrated a significant main effect of age group on the mean VOR gain at the one-year follow-up (p = 0.018), and it also found a significant interaction between the factors of gender, age group, HTN (p = 0.043).

CONCLUSIONS

CVRFs do not independently affect the mean VOR gain in VN patients' follow-ups. However, age significantly impacts VOR gain in VN and could be modulated by gender and hypertension.

Factors affecting variability in vestibulo-ocular reflex gain in the Video Head Impulse Test in individuals without vestibulopathy: A systematic review of literature

Introduction

The purpose of this systematic review was to summarize and synthesize published evidence examining variations in vestibulo-ocular reflex (VOR) gain outcomes for the Video Head Impulse Test (vHIT) in healthy individuals without vestibulopathy in order to describe factors that may influence test outcomes.

Methods

Computerized literature searches were performed from four search engines. The studies were selected based on relevant inclusion and exclusion criteria, and were required to examine VOR gain in healthy adults without vestibulopathy. The studies were screened using Covidence (Cochrane tool) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards (PRISMA-2020).

Results

A total of 404 studies were initially retrieved, of which a total of 32 studies met inclusion criteria. Four major categories were identified which lead to significant variation in VOR gain outcomes: participant-based factors, tester/examiner-based factors, protocol-based factors, and equipment-based factors.

Discussion

Various subcategories are identified within each of these classifications and are discussed, including recommendations for decreasing VOR gain variability in clinical practice.

A review of the geometrical basis and the principles underlying the use and interpretation of the video head impulse test (vHIT) in clinical vestibular testing

This paper is concerned mainly with the assumptions underpinning the actual testing procedure, measurement, and interpretation of the video head impulse test-vHIT. Other papers have reported in detail the artifacts which can interfere with obtaining accurate eye movement results, but here we focus not on artifacts, but on the basic questions about the assumptions and geometrical considerations by which vHIT works. These matters are crucial in understanding and appropriately interpreting the results obtained, especially as vHIT is now being applied to central disorders. The interpretation of the eye velocity responses relies on thorough knowledge of the factors which can affect the response-for example the orientation of the goggles on the head, the head pitch, and the contribution of vertical canals to the horizontal canal response. We highlight some of these issues and point to future developments and improvements. The paper assumes knowledge of how vHIT testing is conducted.

Exploratory saccades data analysis of video head impulse test in Different Meniere's Disease Stages

BACKGROUND

Unapparent saccades in video head impulse test (vHIT) are usually present in MD patients but tend to be ignored by the clinician. The result of vHIT is constantly questioned in MD patients due to a lack of uniform metrics. A more effective indicator is needed for indicating MD's pathological progress.

OBJECTIVES

To get a comprehensive understanding of the nature and usability of saccades in different MD stages.

METHODS

118 patients diagnosed with unilateral MD were recruited in this study. Patient history, audiological examination, caloric test, vHIT were performed. We proposed 'raw saccades' to represent all showed wave peaks behind the head peak and named saccades by their appearance sequence: 1st saccade, 2nd saccade and 3rd saccade. An exploratory saccade analysis was executed to investigate the effectiveness of saccade attributes in identifying MD stages.

RESULTS

MD patients have greater detectable 1st saccade than PR score as well as 2nd saccade. The time and velocity of the 1st saccade show high interaural variability (p = 0.028, p = 0.000 respectively). No statistical difference concerning the vHIT gain, PR score and 2nd saccade among stages could be recognized on both affected and contralateral sides. Multiple comparisons show the affected 1st saccade velocity and affected 1st saccade absolute velocity have stage-difference. At late stages (3&4), the affected 1st saccade is manifested as a speed increase, and this measure shows a relatively high correlation with MD stages compared to other vestibular indicators.

CONCLUSION

The 1st saccade velocity on the affected side could indicate the MD disease process and severity.

Diagnosing vestibular hypofunction: an update

Unilateral or bilateral vestibular hypofunction presents most commonly with symptoms of dizziness or postural imbalance and affects a large population. However, it is often missed because no quantitative testing of vestibular function is performed, or misdiagnosed due to a lack of standardization of vestibular testing. Therefore, this article reviews the current status of the most frequently used vestibular tests for canal and otolith function. This information can also be used to reach a consensus about the systematic diagnosis of vestibular hypofunction.

Vestibular Neuritis in Patients Among Different Age Groups: Clinical Features and Outcomes

BACKGROUND

Patients with vestibular neuritis (VN) displayed differential prognosis despite of the same treatment. Thus, identifying unique characteristics in different populations and creating individually customized treatments are necessary. However, studies about the clinical features according to different ages are scarce.

PURPOSE

This article compares the differences in VN patients among different age groups.

RESEARCH DESIGN

A prospective study.

STUDY SAMPLE

A total of 70 VN patients were enrolled in the present study.

INTERVENTION

All the patients started vestibular rehabilitation at the time of initial presentation to our clinic. They were followed up at 1-month intervals using the questionnaire until 4 months.

DATA COLLECTION AND ANALYSIS

Patients' clinical data including clinical presentation, vestibular testing results, treatment, and recovery was collected and analyzed with Duncan's multiple range test, the sign test, and the Kruskal-Wallis test using SPSS18.0.

RESULTS

The mean age of the 70 patients was 47.2 ± 17.1, ranging from 10 to 76 years old. The sex ratios (male:female) were 3.5 in the adolescent group, 0.643 in the young adult group, 1.375 in the middle-aged group, and 0.583 in the senior group. The prevalence of hypertension and diabetes mellitus showed a significantly increasing trend from young adults to the seniors (p < 0.05). The caloric response was statistically worse in the senior group than the other groups (p < 0.05). The abnormal rates for video head impulse test, vestibular-evoked myogenic potential, and vestibular autorotation test did not differ significantly in different age groups. A significant difference between prerehabilitation and postrehabilitation total Dizziness Handicap Inventory (DHI) scores was identified in all the groups (p < 0.05). The younger patients demonstrated a greater improvement than patients in the senior group, meanwhile adolescents improved the most (p < 0.05). Hospital Anxiety and Depression Scale (HADS) was the lowest in the adolescent group (p < 0.05). DHI score at acute stage was significantly correlated with HADS (r = 0.597, p < 0.05).

CONCLUSION

The canal response was statistically better for younger patients compared with the elderly. The younger patients demonstrated a greater improvement than patients in the senior group, among whom adolescents improved the most, meanwhile psychological factors played a minor role in adolescents. Self-perceived disability-handicap positively correlated with anxiety and depression in all patients.

Quantitative Analysis of Saccade Gain in Video Head Impulse Testing

OBJECTIVE

To quantitatively analyze corrective saccade (CS) gain and further characterize the specific relationship between vestibulo-ocular reflex (VOR) gain and CS gain in patients with vestibular loss and healthy controls.

STUDY DESIGN

Prospective combined with retrospective study.

SETTING

Affiliated Sixth People's Hospital, Shanghai Jiao Tong University.

SUBJECTS AND METHODS

Forty patients with unilateral vestibular loss and 40 participants with normal vestibular function were subjected to video head impulse testing (vHIT). The analysis of the horizontal semicircular canal VOR and CS gains was based on individual head impulses.

RESULTS

The patient group had significantly higher CS gain and lower VOR gain than the control group (P < .001). While there was no significant correlation between VOR and CS gains in the control group after adjusting for age and sex (P = .689), VOR gain negatively correlated with CS gain in the patient group (r = -0.853, P < .001). The specific relationship between VOR and CS gains was characterized as y = -1.17x + 1.12 (x: VOR gain, y: CS gain; r ² = 0.732, P < .001) in the patient group.

CONCLUSIONS

In healthy participants, CS was not correlated with VOR gain, suggesting that CS is not due to VOR hypofunction. In patients with unilateral vestibular loss, CS was closely associated with VOR gain and can almost correct gaze position errors required for visual stabilization. CS gain could be an important indicator to diagnose vestibular loss and help physicians identify abnormal vHIT curves caused by artifacts and irregular practices.

Effect of Gaze Angle During the Vertical Video Head Impulse Test Across Two Devices in Healthy Adults and Subjects With Vestibular Loss

OBJECTIVE

To evaluate the effect of gaze angle on vertical vestibulo-ocular reflex (VOR) gain using two different video head impulse (vHIT) devices in healthy adults and subjects with bilateral vestibular loss (BVL).

STUDY DESIGN

Prospective study.

SETTING

Hospital research laboratory.

SUBJECTS

Twenty-four healthy adults (mean [standard deviation {SD}] age = 32 [4.8]; 23-42; 8 men) and four subjects with previously diagnosed BVL (mean age [SD] = 32 [8.2]; 21-40; 3 men) participated.

INTERVENTION

Vertical canal vHIT was administered with two different devices using three gaze angles (-45 degrees, 0 degree, +45 degrees). These devices have different gain calculation algorithms and different head and gaze angle protocols.

MAIN OUTCOME MEASURES

Vertical canal gain and presence or absence of reset saccades.

RESULTS

A significant stepwise reduction in vHIT gain was noted as gaze moved away from the plane of the canals stimulated (from -45 degrees to 0 degree, to +45 degrees) for both healthy adults and subjects with BVL. vHIT gain was able to separate the two groups using gaze angles -45 degrees and 0 degree.

CONCLUSIONS

In spite of their differences in gain algorithm and recommended head position and gaze angle, each device was able to appropriately separate healthy adults from subjects with BVL with high sensitivity/specificity.