Static Subjective Visual Vertical Research Articles

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.

Perceptual visual dependence for spatial orientation in patients with schizophrenia.

Patients with schizophrenia are reported to have vestibular dysfunction and to weigh vestibular input to a lesser extent compared to healthy controls. Such deficits may increase visual dependence (VD) for spatial orientation at a perceptual level in these patients. The aim of this study is to compare VD levels between healthy control and patients with schizophrenia and to explore associations between VD and clinical measures in these patients. Relation of VD to antipsychotic drug treatment is also discussed. 18 patients with schizophrenia and 19 healthy controls participated in this study. The Rod and Disc Test (RDT) was used to create an optokinetic surround around a centrally located rod. Participants aligned the rod to their subjective visual vertical (SVV) in both static and dynamic disc conditions. VD was calculated as the difference in SVV between these two conditions. There was no group difference or gender difference in static or dynamic SVV as well as VD. There was no correlation between VD and any of the Positive and Negative Syndrome Scale (PANSS) scores, however VD was significantly correlated to illness duration in the patient group. Schizophrenia is not associated with greater VD levels at a perceptual level, compared to controls, indicating adequate visuo-vestibular integration for judging line verticality in these patients. Patients with greater chronicity of the disease are more visually dependent than those less chronically ill, consistent with previous reports of possible vestibular dysfunction in patients with schizophrenia. This may affect their daily functioning in dynamic visual environments.

Dynamic changes of otolith organ function before and after repositioning in patients with benign paroxysmal positional vertigo detected by virtual reality auxiliary technology: A cohort study.

To dynamically investigate otolith function in patients with benign paroxysmal positional vertigo (BPPV) before, after, and 1 month after repositioning, and explore the possible compensation mechanisms. Thirty-six patients confirmed with BPPV (canal lithiasis) treated in our hospital between August 2020 and March 2021, as well as 36 health controls matched for age and gender (normal control group, NC group) were enrolled. For NC group, the virtual reality (VR) auxiliary static subjective visual vertical (SVV), subjective visual horizontal (SVH), and SVV of dynamic unilateral centrifugation (DUC), were measured at inclusion. For the BPPV group, visual analog scale (VAS) was used to assess the vertigo degree, while static SVV, SVH, and DUC were performed before, after, and 1 month after repositioning. First, we compare the deviations of SVV0/SVH0° when the subject's head is in the positive position, and SVV of DUC between BPPV and NC groups before repositioning, after which we compared the deviations in SVV45, SVV90, SVH45, SVH90°, and SVV of DUC between the affected and unaffected sides before repositioning. Finally, paired t-test was used to compare the VAS score, deviations in static SVV0, SVV45, SVV90, SVH0, SVH45, and SVH90°, and deviations in SVV of DUC before, after, and 1 month after repositioning. (Here, 0, 45, and 90° refer to the angle which the center axis of head deviates from the gravity line.). SVV0 SVH0°, and SVV of DUC at 120 and 180°/s 0 significantly differed between BPPV and NC group before repositioning. The deviations in SVV45, SVV90, SVH45, SVH90°, and SVV of DUC at 120°/s-2 and 180°/s-4.5 did not significantly differ between bilateral sides in BPPV patients before repositioning. The deviation in SVH90° was significantly lower after repositioning than before. The deviation in SVH45° was significantly higher 1 month after repositioning than before. The deviation angle of SVV of DUC at 180°/s-0 was significantly lower after repositioning than before. The vertigo VAS score of patient with BPPV continued to decrease after repositioning. Before repositioning, the otolithic organ function of BPPV patients was obviously impaired, with no significant difference between the healthy and affected ear. After repositioning, there was a transient recovery of otolithic organ dysfunction followed by a sustained decline to similar levels to before repositioning.

Subjective visual vertical deviation in patients with early-onset direction-changing horizontal positional nystagmus

ObjectiveOtolithic dysfunction is investigated in cases of direction-changing horizontal positional nystagmus (DCHPN) due to peripheral vestibular disorders. MethodsThe static-subjective visual vertical (S-SVV) was conducted in DCHPN cases within 48 h after onset. ResultsThe absolute values of S-SVV deviations of patients with Light cupula and lateral canal-benign paroxysmal positional vertigo-cupulolithiasis (L-BPPV-Cup) were significantly different from those of healthy subjects (p < 0.001, p < 0.05, respectively), whereas there were no significant differences in those of patients with L-BPPV-Canalolithiasis-geotropic (L-BPPV-Can-g) or L-BPPV-Can-ageotropic (L-BPPV-Can-a) versus healthy subjects. Significant differences were found in S-SVV (+: deviation to the affected side, −: deviation to the unaffected side) between patients with Light cupula and those with L-BPPV-Can-g, L-BPPV-Can-a and L-BPPV-Cup (p < 0.01, p < 0.05, and p < 0.001, respectively), as well as between those with L-BPPV-Can-g and L-BPPV-Cup (p < 0.01). The S-SVV in patients with Light cupula, L-BPPV-Can-g, and L-BPPV-Can-a deviated more to the affected side, whereas that in patients with L-BPPV-Cup deviated more to the unaffected side. ConclusionMild otolithic dysfunctions were found in patients with DCHPN due to the presence of peripheral vestibular disorders within 48 h after onset. The extent of otolithic (utricular) disorders in patients with DCHPN is estimated in decreasing order as follows: Light cupula > L-BPPV-Cup > L-BPPV-Can-g and L-BPPV-Can-a. Many patients with L-BPPV-Cup likely suffer from disorders of the pars externa of the utricular macula, whereas many patients with L-BPPV-Can-g likely suffer from disorders of the pars interna of the utricular macula. L-BPPV-Can-a and L-BPPV-Can-g must be induced by a common mild utricular disorder.

Impaired Subjective Visual Vertical and Increased Visual Dependence in Older Adults With Falls.

Aging affects the vestibular system and may disturb the perception of verticality and lead to increased visual dependence (VD). Studies have identified that abnormal upright perception influences the risk of falling. The aim of our study was to evaluate subjective visual vertical (SVV) and VD using a mobile virtual reality-based system for SVV assessment (VIRVEST) in older adults with falls and evaluate its relationship with clinical balance assessment tools, dizziness, mental state, and depression level. This study included 37 adults >65 years who experienced falls and 40 non-faller age-matched controls. Three tests were performed using the VIRVEST system: a static SVV, dynamic SVV with clockwise and counter-clockwise background stimulus motion. VD was calculated as the mean of absolute values of the rod tilt from each trial of dynamic SVV minus the mean static SVV rod tilt. Older adults who experienced falls manifested significantly larger biases in static SVV (p = 0.012), dynamic SVV (p < 0.001), and VD (p = 0.014) than controls. The increase in static SVV (odds ratio = 1.365, p = 0.023), dynamic SVV (odds ratio = 1.623, p < 0.001) and VD (odds ratio = 1.460, p = 0.010) tilt by one degree significantly related to falls risk in the faller group. Fallers who had a high risk of falling according to the Tinetti test exhibited significantly higher tilts of dynamic SVV than those who had a low or medium risk (p = 0.037). In the faller group, the increase of the dynamic SVV tilt by one degree was significantly related to falls risk according to the Tinetti test (odds ratio = 1.356, p = 0.049). SVV errors, particularly with the dynamic SVV test (i.e., greater VD) were associated with an increased risk of falling in the faller group. The VIRVEST system may be applicable in clinical settings for SVV testing and predicting falls in older adults.

Young and Older Adults Differ in Integration of Sensory Cues for Vertical Perception.

Introduction The subjective visual vertical (SVV) measures the perception of a person's spatial orientation relative to gravity. Weighted central integration of vestibular, visual, and proprioceptive inputs is essential for SVV perception. Without any visual references and minimal proprioceptive contribution, the static SVV reflects balance of the otolith organs. Normal aging is associated with bilateral and progressive decline in otolith organ function, but age-dependent effects on SVV are inconclusive. Studies on sensory reweighting for visual vertical and multisensory integration strategies reveal age-dependent differences, but most studies have included elderly participants in comparison to younger adults. The aim of this study was to compare young adults with older adults, an age group younger than the elderly. Methods Thirty-three young and 28 older adults (50–65 years old) adjusted a tilted line accurately to their perceived vertical. The rod's final position from true vertical was recorded as tilt error in degrees. For otolithic balance, visual vertical was recorded in the dark without any visual references. The rod and frame task (RFT) with tilted disorienting visual frames was used for creating visuovestibular conflict. We adopted Nyborg's analysis method to derive the rod and frame effect (RFE) and trial-to-trial variability measures. Rod alignment times were also analyzed. Results There was no age difference in signed tilts of SVV without visual reference. There was an age effect on RFE and on overall trial-to-trial variability of rod tilt, with older adults displaying larger frame effects and greater variability in rod tilts. Alignment times were longer in the tilted-frame conditions for both groups and in the older adults compared to their younger counterparts. The association between tilt accuracy and tilt precision was significant for older adults only during visuovestibular conflict, revealing an increase in RFE with an increase in tilt variability. Correlation of σSVV, which represents vestibular input precision, with RFE yielded exactly the same contribution of σSVV to the variance in RFE for both age groups. Conclusions Older adults have balanced otolithic input in an upright position. Increased reliance on visual cues may begin at ages younger than what is considered elderly. Increased alignment times for older adults may create a broader time window for integration of relevant and irrelevant sensory information, thus enhancing their multisensory integration. In parallel with the elderly, older adults may differ from young adults in their integration of sensory cues for visual vertical perception.

Subjective Verticality Is Disrupted by Astigmatic Visual Distortion in Older People.

PurposeThere is little research evidence to explain why older adults have more problems adapting to new spectacles incorporating astigmatic changes than younger adults. We tested the hypothesis that astigmatic lenses oriented obliquely would lead to errors in verticality perception that are greater for older than younger adults.MethodsParticipants included 12 young (mean ± SD age 25.1 ± 5.0 years) and 12 older (70.2 ± 6.3 years) adults with normal vision. Verticality perception was assessed using a computer-based subjective visual vertical (SVV) task, under static and dynamic (in the presence of a moving peripheral distractor) conditions and when viewing targets through the near refractive correction (control condition), and two forms of astigmatic lenses oriented in the vertical, horizontal, and oblique meridians.ResultsThe older group demonstrated much greater dynamic SVV errors (e.g., 3.4° for the control condition) than the younger group (1.2°, P = 0.002), larger errors with vertical and horizontal astigmatic lenses (older group 4.1°and 5.2° for toric and magnifier lenses vs. younger group 1.2° and 1.4°, respectively, P < 0.001), and a larger influence of the oblique astigmatic lenses (older group 5.6° vs. younger group 2.1°, P<0.001).ConclusionsAstigmatic lenses produced little or no errors in SVV in young adults, but large static and dynamic SVV errors in older adults. This indicates a greater reliance on visual input with increased age for SVV, and helps explain why oblique astigmatic refractive corrections can cause dizziness in older patients and why they report greater difficulties adapting to new spectacles with astigmatic changes.

The influences of age, gender and geometric pattern of visual image on the verticality perception: A subjective visual vertical (SVV) study among Malaysian adults.

Subjective visual vertical (SVV) is a simple, quick and reliable test for measuring utricular function. The literature on the effects of fundamental demographic variables such as age and gender on SVV is inconclusive and should be supported by research with larger samples. The aim of the present study was to determine the influences of age, gender and geometric pattern of visual image on SVV among healthy adults. This study employed a repeated measures design. Otorhinolaryngology Clinic, Hospital Universiti Sains Malaysia, Malaysia. Eligible Malaysian adults (N=187, aged 21-75years) were recruited and categorised into young (N=60), middle-aged (N=66) and older (N=61) groups. Most of them were Malay, and 51.3% were men. Subjective visual vertical angles (in degrees) were determined from each participant in a static upright condition using a computerised SVV device. They were asked to indicate their verticality perception for three types of visual images (solid line, dotted line and arrow pattern). Three-way mixed ANOVA revealed insignificant influences of age and gender on SVV results (P>0.05). In contrast, mean SVV angles were significantly higher for the arrow pattern than for other visual images (P=0.004). While the insignificant influences of age and gender on static SVV are further ascertained with larger samples, the perception of verticality is less accurate when aligning a more geometrically complex visual image (ie, arrow pattern). Further SVV research on vestibular-disordered patients is beneficial, particularly to verify the normative data obtained with this complex visual image.

A pilot study of the unilateral centrifugation subjective visual vertical in healthy young people

Objective: To evaluate the data of unilateral centrifugation subjective visual vertical (UC-SVV) in healthy young people.To study the function of utricle. Methods: Between Decem ber 2017 and May 2018, thirty-two healthy young volunteers were tested by static subjective visual vertical(SVV) and low velocity UC-SVV with Neuro Kinetics Inc I-portal 6.0 Video nystagmus recording system and NOTC rotating chair system.The static SVV preset angle were -15.00°, 15.00°, -20.00°, 20.00°, -12.00° and 12.00° respectively.UC-SVV test parameters: rotating chair's peak speed was 60°/s.The shift time from the middle to the lateral position was 30 s and the displacement was 3.85 cm.The chair rotated at 60 s at left, right and middle positions.Subjects underwent SVV during this period.SPSS 17.0 software was used to analyze the data. Results: The mean and standard deviation of static SVV deviation in 32 volunteers was 0.21°±0.17°, 95%CI (-0.14°, 0.55°). The mean and standard deviation of UC-SVV in the left, middle and right positions of the clockwise was 0.24°±0.25°, -0.10°±0.27°, -0.63°±0.26°, 95%CI(-0.26°, 0.74°), (-0.65°, 0.44°), (-1.16°, -0.10°). The mean and standard deviation of UC-SVV in the left, middle and right positions of the counter clockwise was 0.03°±0.27°, -0.11°±0.26°, -0.23°±0.26°, 95%CI(-0.52°, 0.59°), (-0.65°, 0.42°), (-0.76°, 0.30°). There was significant difference in the deviation between the left and the right side of counter clockwise rotation of UC-SVV(t=2.432, P<0.05), however, there was no significant difference in the angle of deviation between the left and right sides and the median position(t value was 0.951, -1.400, both P>0.05). There was no significant difference among each position in clockwise rotation of UC-SVV(F=0.253, P>0.05). Conclusion: UC-SVV test with peak speed of 60°/s can cause vertical line deviation in the left and right lateral position, but the angle is small and the value of clinical application is limited.

Sense of verticality in girls with right thoracic adolescent idiopathic scoliosis (AIS): Evaluation of bottom up and top down mechanisms

Objective AIS is the most frequent spinal deformity in adolescence, but its etiology remains unknown. We hypothesized that AIS is secondary to perturbation of sense of verticality. Orthostatic postural control is organized, in part, from the vertical gravity, by two mechanisms: bottom up (central integrating of multisensorial inputs) and top down (cognitive process, as notion of self-image representation). We studied sense of verticality in SIA by subjective visual vertical (SVV), postural vertical (VP) and self-image representation, with reference to the vertical gravity. Material/patients and methods We conducted two prospective multicentre case–control studies. Study 1 aimed at the evaluation of static and dynamic SVV and VP, in two groups. Thirty girls (14.2 ± 1.7 years) with right thoracic AIS (3.97 ± 12.9°), matched to 30 controls (13.9 ± 1.8 years). Study 2 aimed at the evaluation of perception of form trunk with pictorial scale in three groups. Thirty-one girls (13.5 ± 1.3 years) with minor right thoracic AIS, 32 girls (14 ± 0.9 years) with major right thoracic AIS, 30 control girls (13.6 ± 1.3 years). A weighted score is established: higher score reveal worse perception of trunk form. Results Study 1 found no significant difference in SVV and VP was shifted to the right in right thoracic AIS group: 2.1 ± 2.2° vs. score control group = 0.08° ± 1.4° (P Discussion, conclusion Our studies show disturbance of sense of verticality in AIS, with somaesthesic graviception disorder. The loss of concordance between central internal representation of verticality and earth-vertical could lead to a perturbation of longitudinal body axis, by impaired postural adjustment of the trunk. AIS could be the result of a reorientation of longitudinal body axis, consequently of spinal axis, in accordance with an erroneous representation of verticality. This model modifies the management of scoliosis AIS.

Normal values of otolith function tests and age-related changes

Objective:To explore the normal values of otolith function tests and agerelated changes in health volunteers.Method: One hundred and seventyone health volunteers were distributed to seven age groups, all subjects accepted otolith function tests, including fundus photography, static subjective visual vertical(SSVV), cervical vestibular evoked myogenic potential(cVEMP)and ocular vestibular evoked myogenic potential(oVEMP), the fundus photographs was used to measure the discfovea angle(DFA). DFA, SSVV and VEMPs were analyzed and compared among groups. Result: For DFA and SSVV,there were no significant differences either between different ages or between the two eyes in one individual（P>0.05）. For cVEMP, the detection rate declined with age over 60 years old（P<0.01）; the cVEMP threshold increased with every 20 years old(P<0.05); and the cVEMP amplitude decreased with every 10 years old(P<0.05),however, there was an exception that no significant difference was found between 41-50 years old and 51-60 years old groups（P=0.93）;the cVEMP P1 latency prolonged with age over 70 years old（P<0.01）.For oVEMP, the detection rate also declined with age over 60 years old（P<0.01）; the oVEMP threshold was lowest at the age less than 30 years old and the largest threshold was found at the age over 70 years old（P<0.01）; consistently, the oVEMP amplitude was found largest at the age less than 20 years old and lowest at the age over 60 years old(P<0.05).The P1 and N1 latencies were found significantly longer in the group of over 70 years old than other groups（P<0.01）.No significant difference was found between both sides in one individual for oVEMP threshold,amplitude or latency (P>0.05). Conclusion: In health volunteers,there were no obvious aged related changes in DFA and SSVV. However,the detection rate, threshold, amplitude and latency of cVEMP and oVEMP greatly changed with age.

Stimulation from Cochlear Implant Electrodes Assists with Recovery from Asymmetric Perceptual Tilt: Evidence from the Subjective Visual Vertical Test.

Vestibular end organ impairment is highly prevalent in children who have sensorineural hearing loss (SNHL) rehabilitated with cochlear implants (CIs). As a result, spatial perception is likely to be impacted in this population. Of particular interest is the perception of visual vertical because it reflects a perceptual tilt in the roll axis and is sensitive to an imbalance in otolith function. The objectives of the present study were thus to identify abnormalities in perception of the vertical plane in children with SNHL and determine whether such abnormalities could be resolved with stimulation from the CI. Participants included 53 children (15.2 ± 4.0 years of age) with SNHL and vestibular loss, confirmed with vestibular evoked myogenic potential (VEMP) testing. Testing protocol was validated in a sample of nine young adults with normal hearing (28.8 ± 7.7 years). Perception of visual vertical was assessed using the static Subjective Visual Vertical (SVV) test performed with and without stimulation in the participants with cochleovestibular loss. Trains of electrical pulses were delivered by an electrode in the left and/or right ear. Asymmetric spatial orientation deficits were found in nearly half of the participants with CIs (24/53 [45%]). The abnormal perception in this cohort was exacerbated by visual tilts in the direction of their deficit. Electric pulse trains delivered using the CI shifted this abnormal perception towards center (i.e., normal; p = 0.007). Importantly, this benefit was realized regardless of which ear was stimulated. These results suggest a role for CI stimulation beyond the auditory system, in particular, for improving vestibular/balance function.

Static Subjective Visual Vertical in Healthy Volunteers: The Effects of Different Preset Angle Deviations and Test-Retest Variability

ABSTRACTThe static subjective visual vertical (SVV) was assessed in 24 healthy volunteers with different preset angles (i.e., 10, 20, and 30 degrees), and in 20 other volunteers, the static SVV was tested and retested 1 week later. The static SVV results are influenced by the side of the preset angle (Wilcoxon test, p ≤ 0.001), but not by the preset angle deviation. The test-retest static SVV outcomes are stable at a group level; however, they show statistically relevant variability at an individual level (−0.240 ≤ intraclass correlation coefficient [ICC] ≤ 0.508). A robust static SVV protocol is described in this paper.

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

IntroductionDetection 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. ObjectiveThe goal of this study was to determine the efficacy of a smartphone-based SVV test at detecting PVL in pediatric patients. MethodsThirty-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. ResultsMean 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. ConclusionSmartphone-based SVV testing is a simple and useful office-based method for detecting PVL in children with dizziness.

Subjective visual vertical testing in children and adolescents.

Subjective visual vertical (SVV) is a vestibular test commonly used in adults that has not been well studied in children. In this test, the patient aligns a projected line with the perceived true vertical. Deviation of >2° is usually associated with utricular dysfunction and may also be seen with central vestibular lesions. The goal of this study was to determine the efficacy of SVV in children. Prospective, controlled study. Thirty-three children aged 7 to 18 years with (n = 21) and without (n = 12) dizziness underwent static SVV. History, exam, rotary chair, and caloric testing were used to categorize subjects with dizziness into groups with peripheral vestibular loss (PVL), benign paroxysmal positioning vertigo (BPPV), central vertigo (CV), and nonvestibular dizziness (NVD). Mean SVV deviation was significantly higher in the peripheral vestibular loss group (n = 4; 2.1 ± 1.5) compared to BPPV (n = 5; 0.5 ± 0.3), CV (n = 7; 0.4 ± 0.3), NVD (n = 5; 0.6 ± 0.4), and control (n = 12; 0.7 ± 0.5) groups by one-way analysis of variance (P = .002). SVV deviation >2° demonstrated a sensitivity of 100%, specificity of 75%, positive predictive value of 100%, and negative predictive value of 97% for PVL. SVV is a simple, noninvasive test that provides a valuable contribution to the assessment of peripheral vestibular function in children. 3b Laryngoscope, 126:727-731, 2016.

Otolith organ function according to subtype of benign paroxysmal positional vertigo

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. Case series. 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. 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. HC cupulolithiasis shows a lesser degree of utricular dysfunction compared with other subtypes. It could postulate the difference of pathophysiology between canalolithiasis and cupulolithiasis. 4.

Patients with migraine correctly estimate the visual verticality

ObjectiveWe wanted to study otolith function by measuring the static subjective visual vertical (SVV) in migraine patients and in controls with and without kinetosis (motion sickness). Methods and materialForty-seven patients with moderately severe migraine and 96 healthy controls were enrolled. Using a questionnaire, persons with kinetosis were identified. The SVV test was performed in a totally dark room. Subjects wore a stiffneck to stabilize the head in an erect position. They were required to adjust an infrared line to the gravitational vertical with a hand-held infrared remote controlled potentiometer. ResultsThe deviation of SVV in the group of migraine patients was not significantly different from that of controls, regardless of whether an aura was associated. SVV was not significantly influenced by the presence of dizziness/non specific vertigo or kinetosis. ConclusionPatients with moderately severe migraine under prophylactic medication correctly estimate the visual verticality in the headache-free period. It is suggested that a deviation of SVV in a headache-free migraine patient may not be attributed to his migraine disorder as such regardless whether kinetosis is associated.

The use of a neck brace does not influence visual vertical perception

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. To analyze the influence of somatosensory inputs caused by a NB on the SVV. Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

Is there a link between spatial neglect and vestibular function at the cerebellar level?

The role of the cerebellum in vestibular function is well known and generally accepted [1, 3]. In the past, claims of the occurrence of spatial neglect have been raised in patients with cerebellar lesions [9, 12, 15], although, data regarding spatial neglect due to cerebellar lesions are inconsistent [6, 13]. The aims of this study were two-fold: to answer the questions, first, if neglect is a common sign in patients with acute cerebellar lesions, and second, if so, if there is an anatomical link between neglect and vestibular otolith function at the cerebellar level. We investigated a series of 16 acute stroke patients with unilateral leftand right-sided cerebellar lesions (Table 1). Figure 1a illustrates a lesion overlay map of all patients in which the subjects with left-sided lesions were flipped to the right side. Neglect and visual extinction were assessed as described previously [7, 8, 10]. All patients underwent vestibular otolith testing by means of tilts of the subjective visual vertical (SVV) [1, 4]. A mean tilt of more than 2.5 of the static SVV determined binocularly was considered pathological [1, 4]. Lesion analysis was done by brain imaging lesion techniques using MRIcron software [14]. The lesions of all patients were documented by MRI; the MRI protocol was described previously [2]. Only one of the sixteen patients (patient MS) showed neglect (6%), i.e., had six omissions in the Bell’s test on the contralesional side. None of the patients, including the one with a right-sided lesion, patient MS (formally diagnosed as neglect), showed typical behaviour of patients with neglect. Patient MS showed a performance of 23 out of 30 achievable points in the mini-mental state exam (MMSE) [5] compatible with a cognitive impairment. Ipsilesional neglect and extinction was not diagnosed in any of the patients. In contrast, eight out of 16 patients (50%) showed a vestibular otolith dysfunction with a contralesional tilt of SVV, whereas three patients (19%)—including the one patient (MS) with six contralesional omissions in the Bell’s test—had an ipsilesional SVV tilt. Thus, signs of neglect and vestibular otolith function were not associated (Fisher’s exact test p = 0.687). The cerebellar lesions distribution of the patients with SVV tilts affected parts of the biventer lobule, the deep nuclei, the hemispheres and midline structures. However, the location of maximum overlap of the patients with SVV tilts at the lateral border of the dentate nucleus reaching into the cerebellar hemisphere (x = -23; y = 62; z = -37; x = -13; y = 56; z = -37) was not affected in the MRI of patient MS (Fig. 1b, c, d). Contrary to data from patients with lesions of the cerebral cortex [11], our data show no relationship between SVV deviation, i.e. vestibular otolith dysfunction, and spatial neglect at cerebellar level. In accordance with B. Baier (&) F. Thomke F. Birklein M. Dieterich Department of Neurology, University of Mainz, Langenbeckstr. 1, 55131 Mainz, Germany e-mail: baierb@uni-mainz.de

Role of subjective visual vertical test during eccentric rotation in the recovery phase of vestibular neuritis

Objectives By assessing unilateral utricular function at the acute and subacute stages, we sought to determine the ability of the subjective visual vertical (SVV) during eccentric rotation (dynamic SVV) in detecting latent abnormality of otolith dysfunction in unilateral vestibular neuritis. In addition, we compared the validity of the dynamic SVV with static SVV during the compensated recovery phase. Methods The static SVV and dynamic SVV of 19 patients diagnosed with acute unilateral vestibular neuritis and 31 patients diagnosed with the subacute stage of vestibular neuritis were determined in this study. First, the static SVV was measured in a dark booth without rotation. The dynamic SVV was measured during rotation with an eccentric displacement of the head to 3.5 cm from the vertical rotation axis during a constant velocity of 300°/s. Results In the acute stage of vestibular neuritis, the static SVV showed an increase in deviation to the side of the lesion compared to findings in normal subjects. In the subacute stage, it did not differ significantly from that of the normal subjects. The dynamic SVV, however, had a statistically significant increase in deviation to the side of the lesion compared to normal subjects in both the acute and subacute stages. Conclusion The dynamic SVV would be an effective method in detecting latent abnormality of otolith dysfunction in unilateral vestibular neuritis, compared to static SVV, especially compensated unilateral vestibular neuritis.