Abnormal Subjective Visual Vertical Research Articles

Development of a Subjective Visual Vertical Test System Using a Smartphone With Virtual Reality Goggles for Screening of Otolithic Dysfunction: Observational Study.

The subjective visual vertical (SVV) test can evaluate otolith function and spatial awareness and is performed in dedicated vertigo centers using specialized equipment; however, it is not otherwise widely used because of the specific equipment and space requirements. An SVV test smartphone app was developed to easily perform assessments in outpatient facilities. This study aimed to verify whether the SVV test smartphone app with commercially available virtual reality goggles can be used in a clinical setting. The reference range was calculated for 15 healthy participants. We included 14 adult patients with unilateral vestibular neuritis, sudden sensorineural hearing loss with vertigo, and Meniere disease and investigated the correlation between the SVV test results and vestibular evoked myogenic potential (VEMP) results. The SVV reference range of healthy participants for the sitting front-facing position was small, ranging from -2.6º to 2.3º. Among the 14 patients, 6 (43%) exceeded the reference range for healthy participants. The SVV of patients with vestibular neuritis and sudden sensorineural hearing loss tended to deviate to the affected side. A total of 9 (64%) had abnormal cervical VEMP (cVEMP) values and 6 (43%) had abnormal ocular VEMP (oVEMP) values. No significant difference was found between the presence or absence of abnormal SVV values and the presence or absence of abnormal cVEMP and oVEMP values; however, the odds ratios (ORs) suggested a higher likelihood of abnormal SVV values among those with abnormal cVEMP and oVEMP responses (OR 2.40, 95% CI 0.18-32.88; P>.99; and OR 2, 95% CI 0.90-4.45; P=.46, respectively). The SVV app can be used anywhere and in a short period while reducing directional bias by using virtual reality goggles, thus making it highly versatile and useful as a practical otolith dysfunction screening tool.

Static Subjective Visual Vertical (SVV) in Patients with Vestibular Migraine.

Vestibular migraine (VM) is one of the common causes of episodic dizziness, but it is underdiagnosed and poorly understood. Previous research suggests that otolith reflex pathway performance is often impaired in this patient group, leading to altered perception of roll plane stimuli. Clinically, this perception can be measured with subjective visual vertical (SVV) testing. The aim of this study is to compare static SVV performance (absolute mean SVV tilt, variance) in a cohort of patients diagnosed with VM to results obtained from clinically derived normative data. Retrospective case review. Ninety-four consecutive patients between 18 and 65 years of age diagnosed with VM were included in this comparison to clinically derived normative data. Retrospective chart review was completed. Demographic data, symptom report, and vestibular laboratory results were documented. SVV performance was documented in terms of absolute mean SVV tilt and response variance. Abnormal mean SVV tilt was described in 54% (n = 51) of patients with VM. Including abnormal response variance increased those identified with abnormal presentation to 67% (n = 63). Laboratory findings were insignificant for semicircular canal function, but of those with abnormal ocular vestibular myogenic potential results (n = 30), 77% (n = 23) demonstrated both abnormal SVV and utriculo-ocular reflex performance. There were no associations noted for SVV performance and demographic or other self-report variables. Absolute mean SVV tilt and response variance are often abnormal in patients diagnosed with VM. These findings support theories suggesting atypical intralabyrinthine integration within the vestibular nuclei and cerebellar nodular pathways.

Static and dynamic otolith reflex function in people with Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder with possible vestibular system dysfunction. This study reports the transient and sustained functions of the otoliths and their reflex pathways in PD compared to healthy controls (HC) and determines if otolith function relates to previous fall history. Forty participants with PD and 40 HC had their otolith function assessed. Transient saccular and utricular-mediated reflexes were assessed by cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs, respectively) elicited by air-conducted stimulus (clicks) and bone-conducted vibration (light tendon hammer taps). Static otolith function was assessed by the Curator Subjective Visual Vertical (SVV) test. Compared to HC, the PD group had significantly more absent cVEMP responses to both clicks (47.5% vs. 30%, respectively, p = 0.03) and taps (21.8% vs. 5%, respectively, p = 0.002). Only the PD group had bilaterally absent tap cVEMPs, this was related to previous falls history (p < 0. 001). In both groups, click oVEMPs were predominantly absent, and tap oVEMPs were predominantly present. The PD group had smaller tap oVEMP amplitudes (p = 0.03) and recorded more abnormal SVV responses (p = 0.01) and greater error on SVV compared to HC, p < 0.001. SVV had no relationship with VEMP responses (p = 0.14). PD impacts on cVEMP reflex pathways but not tap oVEMP reflex pathways. Bone-conducted otolith stimuli (taps) are more robust than air-conducted sound stimuli (clicks) for both o and cVEMPs. A lack of association between SVV and VEMP responses suggest that static and dynamic otolith functions are differentially affected in PD.

Pisa Syndrome in Parkinson\u2019s Disease: Pathogenic Roles of Verticality Perception Deficits

We elucidated whether verticality misperception is associated with the generation of Pisa syndrome (PS) in patients with Parkinson’s disease (PD). To examine the heterogenous influence of verticality perception, we also identified the characteristics distinguishing between PD patients with PS who tilted toward the deviation of perceived verticality and those who did not. Subjective visual vertical (SVV) testing was performed in 54 PD patients with PS and 36 without PS to measure verticality perception. Other potential risk factors for PS were evaluated by assessing the asymmetry of motor symptoms, EMG activities of paraspinal muscles, bithermal caloric tests, back pain history, and Berg Balance Scale. Abnormal SVV (odds ratio (OR) 18.40, p = 0.006), postural imbalance (OR 0.71, p = 0.046), and unilateral EMG hyperactivity of paraspinal muscles (OR 39.62, p = 0.027) were independent contributors to PS. In subgroup analysis, EMG hyperactivity of paraspinal muscles contralateral to the leaning side and postural imbalance were associated with PD patients with PS who tilted toward the SVV deviation, whereas back pain was more frequent in those who did not. Verticality misperception is a potent risk factor for PS in PD and contributes differentially to PS depending on the congruence between its direction and PS direction, indicating distinct pathogenic roles.

Subjective Visual Vertical in PD Patients with Lateral Trunk Flexion.

Lateral trunk flexion (LTF) is a common phenomenon in patients with Parkinson's disease (PD) and has recently been associated with peripheral vestibular dysfunction. Since deviation of the subjective visual vertical (SVV) is a well-recognized feature of disorders involving vestibular processing, we analyzed SVV angles in 30 PD patients with and without LTF to assess the possible role of vestibular dysfunction in the pathogenesis of LTF in PD. Quantification of SVV was obtained using a simple bedside test. PD patients with LTF had significantly greater SVV angles as compared to PD patients without LTF (median: 4.3° [range: 0.1–17.7], n = 21, versus 0.8° [0.1–1.9], n = 9; p < 0.001). 14 of 21 patients with LTF showed pathological SVV, while all 9 patients without LTF had normal SVV. Abnormal SVV was more frequent when LTF was reversible in the supine position compared to fixed LTF. In a subgroup of PD patients with LTF, pathological SVV suggests vestibular dysbalance, which might be involved in the pathophysiological mechanisms underlying LTF.

Topology of brainstem lesions associated with subjective visual vertical tilt.

We aimed to determine the topology of anatomical pathways for verticality perception in the brainstem. We measured the subjective visual vertical (SVV) in 82 patients with acute unilateral infarction of the brainstem alone. The topology of the brainstem lesions responsible for pathologic SVV tilt were determined using MRI-based voxel-wise lesion-behavior mapping, from which probabilistic lesion maps were constructed. Fifty percent of patients (41/82) with acute unilateral brainstem infarcts had abnormal SVV tilt, of which 76% (31/41) had ipsiversive tilt and 24% (10/41) had contraversive tilt. Patients with contraversive SVV tilt exhibited overlapping lesions of the rostral medial vestibular nucleus, medial longitudinal fasciculus, rostral interstitial medial longitudinal fasciculus, and interstitial nucleus of Cajal. In contrast, patients with ipsiversive SVV tilt and oculomotor disturbances exhibited lesions of the medial and inferior vestibular nuclei in the caudal medulla, while those with isolated vertical perceptual changes had injury to the medial side of the medial lemniscus. Our findings provide evidence of a pathway transmitting ipsiversive otolithic signals that bypass the oculomotor system at the medial side of the medial lemniscus, called the ipsilateral vestibulothalamic tract.

Utricular Dysfunction in Refractory Benign Paroxysmal Positional Vertigo.

To determine the prevalence of otolith dysfunction in patients with refractory benign paroxysmal positional vertigo (BPPV). Unmatched case control. Tertiary care institution. Patients included were diagnosed with BPPV, failed initial in-office canalith repositioning maneuvers (CRMs), and completed vestibular testing and vestibular rehabilitation (n = 40). Refractory BPPV (n = 19) was defined in patients whose symptoms did not resolve despite vestibular rehabilitation. These patients were compared with a control group of those with nonrefractory BPPV (n = 21) for results of a caloric test, cervical vestibular evoked myogenic potential (cVEMP), and subjective visual vertical (SVV). Forty-six of 251 patients failed initial treatment with in-office CRM. Forty patients met inclusion criteria. There was no significant difference between the cases (refractory BPPV) (n = 19) and controls (nonrefractory BPPV) (n = 21) in terms of age, duration of symptoms, laterality of BPPV, and BPPV symptoms. There was no difference in the prevalence of caloric weakness and cVEMP abnormalities (P > .05), with odds ratios (ORs [95% confidence interval (CI)]) of having abnormal results among cases vs controls of 1.1818 (0.3329-4.1954) and 4.3846 (0.7627-25.2048), for caloric and cVEMP, respectively. Abnormal eccentric SVV was more prevalent in refractory BPPV cases (58%) than in controls (14%) (P < .0072). The OR (95% CI) of having abnormal SVV was 8.25 (1.7967-37.8822) higher among patients with refractory BPPV than those with nonrefractory BPPV. Patients with refractory BPPV are more likely to have abnormal eccentric SVV and thus underlying utricular dysfunction. This finding is important to take into account when designing rehabilitation strategies for patients with BPPV who fail CRM.

Impairment of Static Vestibular Function Is Limited in Patients with Sudden Sensorineural Hearing Loss with Vertigo

Sudden sensorineural hearing loss with vertigo (SSNHL_V) and vestibular neuritis (VN) are common neuro-otologic disorders that cause acute spontaneous vertigo. The SSNHL_V and VN lesion sites are thought to be within the labyrinth and the vestibular nerve, respectively. Neurolabyrinthitis of a viral origin is the most commonly accepted etiology of SSNHL_V, and neural degeneration due to viral infection (predominantly in the superior vestibular nerve) is thought to be responsible for the pathophysiology of VN. The objective of this study was to compare the static vestibular imbalance between SSNHL_V and VN patients during the acute stage of the disease. We compared the results of spontaneous nystagmus (SN), subjective visual vertical (SVV), and canal paresis (CP) between SSNHL_V and VN patients within 10 days from the onset of vertigo. Significant SN was observed in 58% of SSNHL_V and 90% of VN patients (p < 0.001), and abnormal SVV was observed in 10% of SSNHL_V and 78% of VN patients (p < 0.001). However, CP values were not significantly different between the 2 groups (50.8 ± 19.7% in SSNHL_V and 57.1 ± 18.9% in VN). In conclusion, significant SN and abnormal SVV are less frequently encountered in SSNHL_V than in VN even though the caloric test did not reveal significant differences at the acute stage.

Subjective visual vertical perception in patients with vestibular neuritis and sudden sensorineural hearing loss

To determine the subjective visual vertical (SVV) perception in patients with vestibular neuritis (VN) and sudden sensorineural hearing loss (SSHL) using the SVV test and other neuro-otological examinations, namely, the vestibular evoked myogenic potential (VEMP) and caloric tests, and to clarify which vestibular nerve function is associated with an SVV shift. We performed the SVV test in 36 VN patients and 80 SSHL patients. Thereafter, we investigated directional changes in the SVV in the VN and SSHL patients, and compared the results of the SVV test with those of the VEMP and caloric tests. Abnormal SVV (> 2° was found at a rate of 69.4% in the VN patients and 26.3% in the SSHL patients. In all except 1 VN patient, the SVV tilted to the lesion side. The rate of abnormal SVV was significantly higher in patients with complete canal paresis (CP) than in patients with partial CP. There was no significant relationship between the rates of abnormal SVV and VEMP. In the SSHL patients, neither the SVV nor the VEMP affected the hearing outcome and patients with abnormal VEMP tended to show abnormal SVV. VN patients showed a higher rate of abnormal SVV than SSHL patients. From the results, it is speculated that the superior vestibular nerve function mainly affects the SVV tilt, although the inferior vestibular nerve function may also have an effect.

Otolith function in patients with head trauma

This study evaluates the otolith function of patients with head trauma, postulating that otolith dysfunction is a cause of nonspecific dizziness after head trauma. We prospectively enrolled 28 patients referred within 3months after head trauma between March 2007 and December 2009. Pure tone audiometry, caloric testing and otolith function tests, including cervical vestibular evoked myogenic potential (cVEMP) and subjective visual vertical (SVV) tests, were performed on all patients. The relationship between otolith function and otologic symptoms was analyzed. Of the 28 patients with head trauma, 18 complained of dizziness and 12 experienced hearing loss, including 6 patients who complained of both. On defining otolith dysfunction as an abnormal cVEMP or abnormal SVV, a significant difference in otolith dysfunction existed between the groups with and without dizziness [72 (13/18) vs. 20% (2/10)]. In contrast, no significant difference in otolith dysfunction was detected between the abnormal and normal hearing groups. A significant number of the patients who complained of nonspecific dizziness after trauma had abnormal otolith function. After trauma, when patients complain of dizziness, vestibular function tests, including otolith function tests, should be considered.

COMMENT

To the Editor: We read with interest the recent article by Kumagami et al. (1). The work is to be commended because they were able to collect solid data on the subjective visual vertical (SVV) before, immediately after, and during recovery from a vertigo attack in a large group of patients with Ménière's disease. The main finding in their study was the presence of a significant tilt of the SVV induced by the attack of Ménière's disease, which they attributed to acute dysfunction of the otolith (in particular, the utricular) system. Although this finding is interesting and useful, we disagree with the authors' interpretation of their result that SVV tilt indicates utricular involvement. Despite the initial enthusiasm with the SVV as a clinical test procedure, there is no clear data to support that abnormal tilts reflect a selectively disordered otolith input. An initial finding by Smith et al. (2), that earth-vertical yaw angular acceleration causes an ocular torsional response, suggested that mechanisms other than otolith stimulation could bring about SVV tilts. Later, Pavlou et al. (3) established that yaw rotational stimuli induce tilt of the SVV (and corresponding ocular torsion) via activation of the vertical semicircular canals, in particular, the posterior canal. This latter finding also explains why an attack of benign paroxysmal positional vertigo (4), which is mediated by posterior canal activation, induces tilt of the SVV as well. Thus, all evidence indicates that tilts of the SVV cannot be taken as evidence of selective otolith lesion or dysfunction. The findings in the interesting article by Kumagami et al. (1) can be equally explained by otolith or semicircular canal dysfunction. In the case of an attack of Ménière's disease, both mechanisms are likely to play a part, but as concluded by Pavlou et al. (3), abnormal SVV tilts cannot be considered a specific indication of otolith system dysfunction. Adolfo M. Bronstein, M.D., Ph.D., F.R.C.P. Kiran Agarwal, M.B.B.S., M.S. Neuro-otology Unit Department of Clinical Neuroscience Imperial College London Charing Cross Hospital London, U.K.

前庭神経炎，突発性難聴における自覚的視性垂直位所見

The measurement of subjective visual vertical (SVV) is clinically used as a method to assess the degree of dysfunction in the otolith, primary vestibular nerves, and central graviceptive pathways. We measured the SVV in patients with vestibular neuritis (VN) and unilateral sudden deafness (uSD). The purpose of this study was to demonstrate the characteristics of SVV in patients with VN and uSD, and determine the relation between the SVV and other neuro-otological examinations, including vestibular evoked myogenic potentials (VEMP) and the caloric test.The SVV was measured in 25 patients suffering from VN (9 women, 16 men aged from 27 to 76 years) and 30 patients suffering from uSD (16 men and 14 women aged from 21 to 76). The SVV was tilted>2o in VN (64.0%) and in uSD (23.3%). Among the abnormal SVV patients (SVV>2o), the tilt was directed toward the affected ear in all VN patients and in 75% of uSD patients.Concerning the caloric test and VEMP in VN patients, there were no significant relationships between the percentages of abnormal SVV and the degree of canal paresis and VEMP. In uSD patients, abnormal VEMP patients tended to show an abnormal SVV. Our results suggest that the shift of the SVV was strongly affected not only by superior vestibular nerve lesions, but also by inferior vestibular lesions.

Treatment of Ménière's Disease by Low‐Dosage Intratympanic Gentamicin Application: Effect on Otolith Function

The intratympanic application of a low dosage of gentamicin is increasingly favored as treatment for Ménière's disease. While posttreatment observations have confirmed a long-term success of the therapy of vertigo attacks, clear differences in the posttreatment recovery interval can be observed. In addition to differences in central-vestibular compensation, the degree of peripheral vestibular damage, i.e., to the saccule, utricle, and semicircular canal ampullae, varies among patients. This study provides comprehensive pre- and posttreatment results from unilateral functional tests of the individual vestibular receptors and of the cochlea in patients with Ménière's disease. Prospective clinical study. Nineteen patients with unilateral Ménière's disease were treated by intratympanic application of gentamicin by injection of 0.3 mL (12 mg) through the tympanic membrane under local anesthesia. Tests were performed immediately previous to treatment and subsequently in the periods 4 to 8 weeks and 12 to 16 weeks after treatment. Unilateral saccular function was tested by means of acoustic-click, vestibular-evoked myogenic potentials (VEMP), and unilateral utricular function by subjective visual vertical (SVV) during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. Prior to gentamicin treatment, the caloric response from the diseased ear was normal in 3 patients, below normal in 14 patients, and in 2 cases almost completely absent. VEMP responses could be recorded bilaterally in 13 patients; while in 6, no VEMPs could be measured from the diseased ear. Utricular function measured by SVV estimation was found to be normal in 11 patients and marginally abnormal in 2 patients. In six cases, the SVV was clearly underestimated during centrifugation of the diseased side. The posttreatment findings demonstrate that VEMPs were absent in all treated patients, and the caloric response was abnormally low in all but one case. In contrast, only 12 of 19 patients produced abnormal SVV responses. The results demonstrate that incremental, intratympanic application of gentamicin effectively eliminates semicircular canal and saccular function. In contrast, utricular function appears to be maintained in 30 to 40% of cases.

The High-Frequency/Acceleration Head Heave Test in Detecting Otolith Diseases

OBJECTIVE:: To investigate whether transient, high-acceleration interaural head heaves (translational vestibulo-ocular reflex [tVOR]) could aid in the diagnosis of otolith diseases. STUDY DESIGN:: Prospective cohort study. SETTING:: Tertiary referral center. PATIENTS:: Thirteen patients with symptoms suggestive of otolith diseases and 10 age-matched controls. INTERVENTIONS:: Patients underwent a clinical otoneurologic examination and standard laboratory audiovestibular evaluation, including audiometry, electronystagmography with bithermal caloric, Halmagyi-Curthoys head thrust test with search coils, and vestibular-evoked myogenic potential. All subjects underwent subjective visual vertical (SVV) and tVOR testings. MAIN OUTCOME MEASURES:: Sensitivity (ratio of peak eye to peak head velocities) and velocity gain (ratio of actual to ideal peak eye velocities). RESULTS:: Five of 13 patients showed no abnormality in any tests. Of the remaining 8, 3 (38%) had reduced tVOR responses, whereas 1 (13%) had abnormal SVV. Sensitivity and velocity gains were symmetrically reduced in 2 patients, who had symptoms for 8 and 24 months. A third patient, symptomatic for 7 weeks, had asymmetric reduction of tVOR responses and a deviated SVV. CONCLUSION:: Both head heave and SVV tests detect acute, asymmetric otolith diseases. Subjective visual vertical test relies on imbalance of utricular tone and may not detect bilateral symmetric diseases or partial diseases with central compensation. Our preliminary data in a small group of patients show that measuring the tVOR in a higher and more physiologic range of frequencies may serve as useful adjunct to detect acute and chronic otolith dysfunction and seems to be superior to the SVV in detecting bilateral symmetric or asymmetric otolith diseases.

Subjective Visual Vertical Perception Relates to Balance in Acute Stroke

Bonan IV, Guettard E, Leman MC, Colle FM, Yelnik AP. Subjective visual vertical perception relates to balance in acute stroke. Objective To determine whether misperception of the subjective visual vertical (SVV) underlies balance difficulties in hemiplegic patients. Design Descriptive study, using a convenience sample. Setting Department of physical medicine of a university hospital. Participants Thirty inpatients with hemiplegia after a hemispheric stroke during the 3 previous months. Interventions Not applicable. Main Outcome Measures The SVV was tested while subjects sat in a dark room and were asked to adjust a luminous line to the vertical position. Mean SVV deviation and uncertainty, defined as the standard deviation, were calculated for 8 trials. Balance was assessed by the Postural Assessment Scale for Stroke (PASS) and while patients sat on a laterally rocking platform placed on a Satel force platform. The mean body position and the instability score (Lx), calculated as the length of the course of the center of pressure, were recorded. Functional outcome was also evaluated by the FIM instrument. Results An abnormal SVV was recorded for 20 of 30 patients. Balance (ie, PASS, Lx) and FIM correlated significantly with SVV tilt ( P<.001, P=.01, and P<.001, respectively) and with uncertainty (PASS, P=.006; FIM, P=.003). Conclusions Verticality misperception was related to poor balance and might be an important element in the assessment of contributing factors to balance disorders after stroke. It should probably be taken into account when establishing balance rehabilitation programs for patients with hemiplegia.

Effect of semicircular canal stimulation on the perception of the visual vertical.

The subjective visual vertical (SVV) is usually considered a measure of otolith function. Herewith we investigate the influence of semicircular canal (SCC) stimulation on the SVV by rotating normal subjects in yaw about an earth-vertical axis, with velocity steps of +/- 90 degrees /s, for 60 s. SVV was assessed by setting an illuminated line to perceived earth vertical in darkness, during a per- and postrotary period. Four head positions were tested: upright, 30 degrees backward (chin up) or forward, and approximately 40 degrees forward from upright. During head upright/backward conditions, a significant SVV tilt (P < 0.01) in the direction opposite to rotation was found that reversed during postrotary responses. The rotationally induced SVV tilt had a time constant of decay of approximately 30 s. Rotation with the head 30 degrees forward did not affect SVV, whereas the 40 degrees forward tilt caused a direction reversal of SVV responses compared with head upright/backward. Spearman correlation values (Rho) between individual SCC efficiencies in different head positions and mean SVV tilts were 0.79 for posterior, 0.34 for anterior, and - 0.80 for horizontal SCCs. Three-dimensional video-oculography showed that SVV and torsional eye position measurements were highly correlated (0.83) and in the direction opposite to the slow phase torsional vestibuloocular reflex. 1) during yaw axis rotation without reorientation of the head with respect to gravity, the SVV is influenced by SCC stimulation; 2) this effect is mediated by the vertical SCCs, particularly the posterior SCCs; 3) rotationally induced SVV changes are due to torsional ocular tilt; 4) SVV and ocular tilts occur in the "anticompensatory," fast phase direction of the torsional nystagmus; and 5) clinically, abnormal SVV tilts cannot be considered a specific indication of otolith system dysfunction.