Subjective visual vertical during eccentric rotation in patients with vestibular neuritis

The Effect of Roll Circular Vection on Roll Tilt Postural Responses and Roll Subjective Postural Horizontal of Healthy Normal Subjects

Background: Falls and related injuries are critical issues in several disease states, as well as aging, especially when interactions between vestibular and visual sensory inputs are involved. Slow support surface tilt (0.6 deg/s) followed by subjective postural horizontal (SPH) assessments have been proposed as a viable method for assessing otolith contributions to balance control. Previous assessments of perceived body alignment to vertical, including subjective visual vertical, have suggested that visual inputs are weighted more when vestibular information is near the threshold and less reliable during slow body tilt. To date, no studies have examined the influence of visual stimuli on slow roll-tilt postural responses and the SPH. Therefore, this study investigated how dynamic visual cues, in the form of circular vection (CV), influence postural responses and the perception of the horizontal during and after support surface tilt. Methods: Ten healthy young adults (6 female, mean age 23) wore a head-mounted display while standing on a tilting platform. Participants were asked to remain upright for 30 s, during which (1) the visual scene rotated, inducing roll CV clockwise (CW) or counter-clockwise (CCW) at 60°/s; (2) the platform only (PO) rotated in roll to test SPH (0.6°/s, 2°, CW or CCW); (3) a combination of both; or (4) neither occurred. During SPH trials, participants used a hand-held device to reset the position of the platform to 0.8°/s to their perceived SPH. The angular motion of body segments was measured using pairs of light-emitting diodes mounted on the head, trunk and pelvis. Segment motion, prior to platform motion, was compared to that at peak body motion induced by platform motion and when SPH had been set. Results: When the support surface was tilted 2°, peak upper body tilt significantly increased for congruent CV and platform tilt and decreased at the pelvis for incongruent CV when compared to PO, leading to significant differences across body segments for congruent and incongruent conditions (p ≤ 0.008). During PO, participants' mean SPH deviated from horizontal by 0.2°. The pelvis deviated 0.2°, the trunk 0.3°, and the head 0.5° in the direction of initial platform rotation. When platform tilt and CV directions were congruent or incongruent, only head tilt at SPH reset under congruent conditions was significantly different from the PO condition (1.7° vs. 0.5°). Conclusions: Roll CV has a significant effect on phasic body responses and a less significant effect on tonic body responses to lateral tilt. The SPH of the support surface was not altered by CV. Responses during tilt demonstrated enhanced reactions for congruent and reduced reactions for incongruent CV, both different from responses to CV alone. Tonic body displacements associated with SPH were changed less than those during tilt and were only slightly larger than displacements for CV alone. This study supports the hypothesis of weighted multisensory integration during dynamic postural tasks being highly dependent on the direction of visual cues during tilt and less dependent on tonic SPH offsets. These techniques could be used to examine vestibular and visual interactions within clinical populations, particularly those with visual vertigo and dizziness.

Independent Measures of Utricular Function: Ocular Vestibular Evoked Myogenic Potentials Do Not Correlate With Subjective Visual Vertical or Fundus Photographic Binocular Cyclorotation

Ocular vestibular evoked myogenic potentials (oVEMPs), subjective visual vertical (SVV), and fundus photographically measured binocular cyclorotation (BCR) are diagnostic tests to assess utricular function in patients with vertigo or dizziness. In 138 patients with chronic vertigo or dizziness, we asked whether the asymmetry ratio of oVEMP (normal, right side pathological, left side pathological) could predict the SVV deviation (normal, rightward deviation, leftward deviation) or BCR (normal, cyclorotation to the right, cyclorotation to the left). There was no correlation between oVEMP and SVV and between oVEMP and BCR, while SVV and BCR correlated highly. Although both oVEMP and SVV measure aspects of utricular function, our findings demonstrate that oVEMP and SVV are not redundant and may reflect different utricular pathologies. The role of fundus photographic BCR may be relegated to only confirm unclear SVV results in vestibular diagnostic workup.

Initial Degree of Spontaneous Nystagmus Affects the Length of Hospitalization of Patients With Vestibular Neuritis

OBJECTIVE

To assess factors predicting vestibular neuritis (VN) prognosis at an early stage.

STUDY DESIGN

Retrospective chart review.

SETTING

University hospital.

PATIENTS

Sixty-five patients with VN, between 2014 and 2018.

INTERVENTIONS

Bithermal caloric test, rotatory chair test, subjective visual horizontal and vertical, cervical visual myogenic evoked potential test, and visual head impulse test (vHIT).

MAIN OUTCOME MEASURES

Hospitalization duration.

RESULTS

The mean hospitalization duration was 4.6 ± 1.4 days. Mean caloric weakness was 65.5 ± 20.6%. For the vHIT, gain in both anterior and horizontal semicircular canal (SCC) was statistically significantly different between the lesion and intact sides (p < 0.001). Backward conditional regression analysis revealed that a higher degree of spontaneous nystagmus (SN) (EXP[B] = 1.104, 95% confidence interval [CI] = 1.012-1.204, p = 0.026), and a lower caloric paresis (CP) value (EXP(B) = 1.033, 95% CI = 1.000-1.075, p = 0.047) were associated with 5 days or more of hospitalization. The cut-off value of SN was 12.05 degrees/s for increased hospital stay. Four weeks after discharge from hospital, five patients (8.9%) had persistent SN, and 19 (33.9%) and 28 (50.0%) had a positive HIT and nystagmus during head-shaking, respectively. Patients with persistent nystagmus at 1 month had more severe initial SN (p < 0.05).

CONCLUSION

Only the degree of SN at the initial evaluation affected both the hospitalization period and the bed-side examination results at 1 month after discharge in patients with VN.

New Mobile Device to Measure Verticality Perception: Results in Young Subjects with Headaches

The subjective visual vertical (SVV) test has been frequently used to measure vestibular contribution to the perception of verticality. Recently, mobile devices have been used to efficiently perform this measurement. The aim of this study was to analyze the perception of verticality in subjects with migraines and headaches. A cross-sectional study was conducted that included 28 patients with migraine, 74 with tension-type headache (TTH), and 93 healthy subjects. The SVV test was used through a new virtual reality system. The mean absolute error (MAE) of degrees deviation was also measured to qualify subjects as positive when it was greater than 2.5°. No differences in the prevalence of misperception in verticality was found among healthy subjects (31.18%), migraineurs (21.43%), or those with TTH (33.78%) (p = 0.480). The MAE was not significantly different between the three groups (migraine = 1.36°, TTH = 1.61°, and healthy = 1.68°) (F = 1.097, p = 0.336, and η2 = 0.011). The perception of verticality could not be explained by any variable usually related to headaches. No significant differences exist in the vestibular contribution to the perception of verticality between patients with headaches and healthy subjects. New tests measuring visual and somatosensory contribution should be used to analyze the link between the perception of verticality and headaches.

Misperception of Visual Vertical in Peripheral Vestibular Disorders. A Systematic Review With Meta-Analysis

OBJECTIVE

The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception.

METHODS

A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method.

RESULTS

Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV.

CONCLUSION

Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.

Peripheral vestibular loss detected in pediatric patients using a smartphone-based test of the subjective visual vertical

INTRODUCTION

Detection of peripheral vestibular loss (PVL) in children with dizziness is an important and challenging task. The static subjective visual vertical (SVV) test can effectively detect PVL, but requires specialized equipment.

OBJECTIVE

The goal of this study was to determine the efficacy of a smartphone-based SVV test at detecting PVL in pediatric patients.

METHODS

Thirty-nine patients between 7 and 18 years old (mean=14.0±2.70) underwent conventional SVV (conv-SVV) and smartphone-based SVV (ip-SVV) testing. Subjects included 6 with PVL (based on clinical history and other vestibular tests), 6 with benign paroxysmal positioning vertigo (BPPV), 11 with central causes of vertigo (CV), 8 with non-vestibular dizziness (NVD), and 8 controls.

RESULTS

Mean ip-SVV score in the PVL group (2.77±1.45) was significantly higher than in each of the other groups (BPPV=0.89±0.55; CV=1.08±0.68; NVD=1.45±1.19; Control=1.08±0.73; one-way analysis of variance, p=0.008), and remained significant after adjusting for age and gender by multiple linear regression analysis. Receiver operating characteristic analysis predicted an optimal ip-SVV cut-off score of >2.13° with a sensitivity of 66.7%, specificity of 97.0%, positive predictive value (PPV) of 80%, and negative predictive value of 94.1% for detecting PVL. Sensitivity and PPV improved to 75% and 100%, respectively, when subjects tested >1 month after symptom onset (n=24) were excluded.

CONCLUSION

Smartphone-based SVV testing is a simple and useful office-based method for detecting PVL in children with dizziness.

Otolith organ function according to subtype of benign paroxysmal positional vertigo

OBJECTIVES/HYPOTHESIS

The clinical features and treatment outcomes of benign paroxysmal positional vertigo (BPPV) are known to be different depending on the type of and involved canal. This difference could be due to differences in the functional change of the otolith organ.

STUDY DESIGN

Case series.

METHODS

Forty-nine patients were diagnosed to primary BPPV; 18 were categorized as posterior canal canalolithiasis (PC canalolithiasis), and 31 were categorized as horizontal canal (HC) BPPV with canalolithiasis or cupulolithiasis (HC canalolithiasis or HC cupulolithiasis). Diagnostic interventions to measure vestibular functions were performed such as electronystagmography (ENG), videonystagmography (VNG), and static and dynamic subjective visual vertical (SVV). BPPV was confirmed with nystagmus during positioning/positional test under ENG and VNG. Static SVV was recorded with a light-emitting diode (LED) bar located in front of the patients before eccentric rotation and dynamic SVV was recorded during eccentric rotation with the LED bar. SVV angles were read by the examiner and analyzed. The measured values were compared to those of normal controls and each other.

RESULTS

Dynamic SVV toward the lesion side in all subtypes of BPPV were significantly different from those of the controls; HC cupulolithiasis showed significantly lower values than those of PC canalolithiasis and HC canalolithiasis.

CONCLUSIONS

HC cupulolithiasis shows a lesser degree of utricular dysfunction compared with other subtypes. It could postulate the difference of pathophysiology between canalolithiasis and cupulolithiasis.

LEVEL OF EVIDENCE

4.