Effect of age on virtual reality-assisted subjective visual vertical and subjective visual horizontal at different head-tilt angles

Abstract Objective: Subjective Visual Vertical (SVV) and Subjective Visual Horizontal (SVH) values may reflect bilateral utricle asymmetry. Bilateral utricle static tension balance can be used to evaluate bilateral otolith lesions and otolith-related central neuropathy. Few studies have examined Virtual Reality (VR)-assisted SVV and SVH values at various head-tilt angles across age groups. The present study aimed to determine the effects of age on VR-assisted SVV and SVH values at different head-tilt angles. Methods: We divided 180 healthy subjects into 6 age groups (n = 30 in each group). VR-assisted SVV and SVH measurements were performed at 9 head-tilt angles (head held vertically, 0°; head tilted 30°, 45°, 60°, and 90° to the left/right) in the roll plane. Results: SVV and SVH values significantly differed with head-tilt angle (p < 0.05). No significant difference was detected in the SVH and SVV values between different age groups (p = 0.632 and p = 0.810, respectively), and no interaction between the age group and the head-tilt angle was found for the SVH and SVV values (p = 0.670 and p = 0.084, respectively). Conclusion: These results suggest that age may have little effect on VR-assisted SVV and SVH at different head-tilt angles. Therefore, VR-assisted SVV and SVH can be evaluated as an effective, fast, and simple way to evaluate utricle function. Level of Evidence: Level 4.

Mastoid Vibration Reduces Ipsilesional Shift of Subjective Visual Horizontal in Patients with Acute Stage of Unilateral Vestibulopathy

BACKGROUND AND OBJECTIVES: To investigate effect of the vibration on subjective visual horizontal (SVH) in patients with acute stage of unilateral vestibulopathy. SUBJECTS AND METHODS: Twenty-five unilateral vestibulopathy patients which analyzed into 42 cases at different time points and suffered from spinning vertigo for more than 24 hours without hearing loss and neurologic abnormality were enrolled. Thirteen subjects with spontaneous nystagmus (>3 degree/sec; averaged symptom onset <1 week) at the time of SVH measurement were classified into the acute unilateral vestibulopathy group (aVU). The other 29 subjects without spontaneous nystagmus were classified into the compensated vestibulopathy group (cVU). SVH was performed with vibration at either mastoid or sterocleidomastoid muscle. RESULTS: In the analysis of overall subjects, vibration did not significantly change the degree of shift of SVH. However, analyzed by group, the shift of SVH with vibration at ipsilesional mastoid was significantly decreased than baseline in aVU (p<0.05). The shift of SVH with vibration at contralesional mastoid was significantly increased than baseline in cVU (p=0.05). CONCLUSIONS: The shift of SVH due to vibration in acute stage of unilateral vestibulopathy showed reduction of the shift, while in compensated stage it showed increase of the shift.

Otolith Function Tests in Patients with Orthostatic Dizziness / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Orthostatic dizziness (OD) is defined as when dizziness is provoked by standing up from a supine or sitting position. It is usually considered as being associated with orthostatic hypotension (OH). On the other hand, it is recently suggested that otolith organ dysfunction and impaired vestibulosympathetic reflex may account for development of OH and OD. Vestibular evoked myogenic potential (VEMP) and subjective visual vertical and horizontal tests (SVV/SVH) are tools for detecting otolith organ dysfunction. We assessed cervical VEMP (cVEMP) and SVV/SVH test results in the patients with OD to evaluate the relationship between OD and otolith organ function. MATERIALS AND METHODS: Three hundred-eighty-seven patients who visited dizziness clinic were enrolled in this study. Seventy-three patients presented with OD (i.e., group O), while 314 patients did not present OD (i.e., group N). Vestibular function tests including cVEMP and SVV/SVH were performed. RESULTS: cVEMP showed abnormal response in 47.9% of group O and 60.2% of group N. Abnormal SVV was found in 35.6% of group O and 31.5% of group N. Abnormal SVH was highly found in both group O and group N (30.1%, 27.1%). CONCLUSION: The values of SVV/SVH and cVEMP abnormality from both groups were not significantly different between the groups O and N. This finding suggests that otolithic function may not be related with OD.

Effect of Preset Angle on Subjective Visual Vertical/Horizontal: Comparison between Normal Subjects and Patients with Dizziness / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Subjective visual vertical (SVV) and subjective visual horizontal (SVH) are well known otolith function tests. Patients with acute unilateral vestibular weakness have a tendency to set the bar toward the side of the lesion in SVV and SVH tests. The object of this article is to identify the effect of preset angle on SVV and SVH tests in normal subjects and patients with dizziness. MATERIALS AND METHODS: From October 2008 to March 2009, thirty healthy volunteers, twenty eight vestibular neuritis (VN) patients (14-uncompensated, 14-compensated), Twenty five patients who had migrainous vertigo (MV) were enrolled. All subjects performed the test two times in each of the clockwise and counter-clockwise preset angle. RESULTS: In normal subjects, there was significant influence by preset angle on SVV test, not on SVH test. In VN patients with nystagmus, both SVH and SVV were not influenced by preset angle. In VN patients without nystagmus and in MV patients, there were significant influence by preset angle on both SVV and SVH tests. CONCLUSION: SVV and SVH values depend on the direction of the preset angle in MV and uncompensated VN patients. The preset angle should be considered in the interpretation of SVV and SVH values.

Clinical Implication of Dissociation between Subjective Visual Horizontal and Subjective Visual Vertical / 대한평형의학회지

BACKGROUND AND OBJECTIVES Subject visual vertical (SVV) and subject visual horizontal (SVH) is well known otolith function test. Patients with acute unilateral vestibular weakness fail to set the test bar within normal range in SVH/SVV showing abnormal deviation toward lesion side. In some cases, SVH and SVV are deviated towards different directions, and analysis of these findings is rarely reported. The authors analyzed correlation of SVH/SVV and other vestibular function tests in patients with various vestibular diseases. MATERIALS AND METHODS From April 2005 to July 2007, total 234 patients who had admitted for dizziness were enrolled. All patients were divided in two groups, non-dissociation group (n=215) and dissociation group (n=19). Correlation of SVH, SVV, Videonystagmography (VNG), the rotating chair test was compared. RESULTS 8.1% of patients showed dissociation between SVH and SVV. Clinical features did not showed significant difference between groups. In non-dissociation group, SVH/SVV showed correlation with VNG, rotating chair test. However in dissociation group, VNG and rotating chair test revealed high rate of consistency with deviation of SVH than that of SVV. Also direction of SVH and dizziness had higher consistency (88.9%) than that of SVV (11.1%). CONCLUSION The SVH showed consistency with other vestibular function test and may be more reliable than SVV when the result is dissociated.

Evaluation of the Otolithic Function in Unilateral Peripheral Vestibulopathy Using Ocular Counterrolling (OCR) and Subjective Visual Horizontal (SVH) / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Most of the vestibular function tests are tests of horizontal semicircular canal function, and those of the otolithic function are limited for use in the clinical setting. Static otolithic dysfunction can be evaluated by ocular counterrolling (OCR) and subjective visual horizontal (SVH). The authors performed this study to confirm the usefulness of OCR and SVH in assessing otolithic function in unilateral peripheral vestibulopathy. MATERIALS AND METHODS: OCR and SVH were measured in 10 unilateral peripheral vestibulopathy patients and their results were compared with those of 10 normal controls. Correlation between the OCR and the SVH was analyzed. The degree of the OCR and the SVH of the patients was compared with gain and asymmetry in the slow harmonic acceleration (SHA) rotation chair test. RESULTS: The OCR of the patients was 3.90+/-5.90degrees inclined toward the lesion side, and was significantly greater when compared with that of control group (1.15+/-1.13degrees) (p<0.05). The patient group aligned the horizontal luminous bar toward the lesion side by 2.95+/-2.78degrees, which differed significantly from the normal mean, 0.11+/-0.16degrees (p<0.01). The tilt of the SVH in the patients was correlated with their OCR's (r=0.84, p<0.05). Correlation between the gain and asymmetry in the SHA rotation chair test, and the degree of the otolothic hypofunction (OCR and SVH) proved to be nearly absent. CONCLUSION: The measurement of the OCR or the SVH may be useful in assessing asymmetries in otolith function in unilateral peripheral vestibulopathy.