Comparisons in Outcome and Subject Comfort between Rotation Chair Systems

BACKGROUND AND OBJECTIVES: A rotation chair test has been used to evaluate the function of the horizontal semicircular canals. Currently, two chair systems according to the presence of cylindrical darkroom are used in a clinic setting. However, it has not been thoroughly investigated whether one system is superior to the other system or not. In this study, we aimed to compare test outcomes and subject convenience between two systems. SUBJECTS AND METHODS: Twenty subjects with no history of otologic disease were enrolled. Subjects were tested with two systems: system [A] with a cylindrical chamber and system [B] with no chamber. The results of sinusoidal harmonic acceleration (SHA), step velocity (SV), and visual fixation (VFX) tests were compared between the systems. Subject convenience was assessed with a questionnaire survey and results were compared between the systems. RESULTS: There were no significant differences in gain or asymmetry in SHA test between the systems. However, the phase of system [A] was significantly lower than that of system [B] at 0.16 Hz. There was no significant difference between the systems in directional preponderance (DP) gain or DP time constant. Regarding the VFX test, gain was higher in system [A] than system [B]. Subjects reported less stuffiness and less anxiety with system [B] than system [A], while preferring the system [A] goggles. CONCLUSIONS: A rotation chair system without a darkroom can provide a more comfortable experience for subjects in terms of stuffiness and anxiety, while showing comparable results in SHA and SV tests with a darkroom system.

Correlation between Rotating Chair Test and Dizziness Handicap Inventory in Patients with Acute Unilateral Vestibular Neuritis / 대한평형의학회지

OBJECTIVE: Vestibular neuritis (VN) is one of the most common causes of acute spontaneous vertigo. However, such dizziness symptoms in patients with VN vary among patients, and various methods are used to evaluate subjective vestibular symptoms following attack of VN. Studies on correlation between subjective vestibular symptom changes and result of rotation chair test after vestibular rehabilitation therapy (VRT) have not been reported. Therefore, we compared change of dizziness handicap inventory (DHI) and results of rotation chair test in patients with VN between attack and 3 month later following VRT. METHODS: Forty-seven patients were included in this study. In patients with VN, DHI and rotation chair test were performed at the time of VN attack and recovery time of 3 months after VN attack. RESULTS: In general, the DHI score and the percentage of directional preponderance (DP) in a rotation chair test performed on patients with VN have all decreased. However, the changes in these results were not statistically significant. DP% difference and DHI score were compared to each other among patients with VN and showed no relational significance to each other (r=0.326). CONCLUSION: The degree of improvement in a rotation chair test done on patients with VN did not reflect the severity of improvement for symptom like dizziness.

Clinical Significance of Spontaneous Nystagmus Frequency in Vestibular Neuronitis / 대한평형의학회지

OBJECTIVE: Spontaneous nystagmus is typical sign in vestibular neuronitis. However, the clinical significance of spontaneous nystagmus frequency remains unclear. The aim of this study is to analyze the spontaneous nystagmus frequency in patients with vestibular neuronitis. METHODS: Twenty-five patients with vestibular neuronitis were included. Patients were divided good (≥20%) and poor (<20%) group according to change of spontanous nystagmus frequency. Frequency and velocity of spontaneous nystagmus were analyzed by using video-nystagmography. Caloric test and slow harmonic acceleration test were also performed. RESULTS: There was a positive linear correlation between frequency and velocity in initial and follow test (R2=0.51, 0.43, p<0.01, p<0.01). Also, there was a strong positive linear correlation betweeng change of frequency and change of velocity (R2=0.64, p<0.01). The phase lead of slow harmonic acceleration test of good group was smaller compared with poor group, and this was statistically significant in 0.04 Hz. CONCLUSION: We suggested that frequency of spontaneous nystagmus may be a useful clinical factor in vestibular neuronitis.

Efficacy of Rotating Chair Test And Caloric Test For The Diagnosis of Acute Unilateral Vestibular Neuritis

BACKGROUND AND OBJECTIVES: The acute unilateral vestibular neuritis is fairly a common disease and the precise diagnostic tool is needed for the selection of effective treatments. Therefore, we studied the clinical usefulness of the rotatory chair test and caloric test which have been commonly used in patient of acute unilateral vestibular neuritis. MATERIALS AND METHODS: One hundred and sixty four patients who were diagnosed with acute unilateral vestibular neuritis from August of 2004 to June of 2007 were included. Their medical records of the rotating chair test and caloric test were reviewed retrospectively to study the correlation of the two tests. RESULTS: Of 164 patients, 101 patients (61.6%) and 88 patients (53.7%) showed significant canal paresis (CP) and directional preponderance (DP) on the caloric tests that corresponded with the physical exam. 130 patients (79.3%) and 84 patients (51.2%) showed significant asymmetry and time constant (Tc) on the rotating chair test that corresponded with the predictive direction with spontaneous nystagmus. CONCLUSIONS: For acute unilateral vestibular neuritis patients, the asymmetry of the rotatory chair test showed the highest correlation with clinical findings. But physical exam should be preceded because neither rotator chair test nor caloric test yields a specific correlation with the physical exam. Especially, single test only may too many false negative results. For these tests can reduce false positive cases of the physical exam and raise the specificity of the diagnosis, the planning of proper treatments should be followed thereafter.

Correlations between MRI and Vestibular Function Test in Central Vestibular Disorder

BACKGROUND & OBJECTIVE: Although some authors (Hamid et at.(1988) ; Moschner et at. (1994)) described that the vestibular function test (VFT) is useful in the differential diagnosis of central vestibular disorders, the reliability of VFT is not well established. The purpose of this study is to know the sensitivity and specificity of VFT for the diagnosis of central vestibular dysfunction. This study correlates VFT and MRI findings in the patients with central vestibular disorder. METHODS: Among the patients who were given VFT and brain MRI study, we selected 131 patients whose VFT results were not compatible with the peripheral vestibular dysfunction. Also we classified the MRI and VFT findings into groups of brainstem or cerebellar lesions and others. We got the sensitivity and specificity of VFT for the diagnosis of central vestibular dysfunction and the differentiation of brainstem or cerebellar lesions from others. Then we compared the results of VFT in each group. Results : 1. Among 71 patients with central vestibular disorder demonstrated by VFT, 41 patients showed lesions in MRI imaging. Among 60 patients whose VFT results were normal, 9 patients were found to have central lesions by MRI. Overall the sensitivity and specificity of VFT for diagnosing the central lesions were 82.0%, 63.0% respectively. 2. Common features in all central vestibular dysfunction patients are abnormalities in CDP and saccade reflex testing. 3. Overall the sensitivity and specificity of VFT for differentiating the brainstem or cerebellar lesions from others were 41.1%, 95.8% respectively. The percentage of patients who showed increased vestibulo-ocular reflex (VOR) gain during gaze fixation test is highly correlated with group of brainstem or cerebellar lesions detected in MRI( p < 0.001). Conclusion : VFT is a sensitive study in detecting and predicting the lesions of central vestibular system. But the ability to differentiate and localize the central lesions is remained to be improved. Key Words ; Vestibular Disorder, Electronystagmography, Rotating chair test, Vestibular function test, Posturography, MRI.

Bilateral Vestibulopathy and Vestibular function test

BACKGROUND AND OBJECTIVES: Many authors(Simmons,1973, McGath et al.,1989) described that a small percentage(1-2 %) of patients initially complaining of vertigo was found to have bilateral vestibular failure (BLVF). This study evaluates the findings of vestibular function test (VFT) including rotating chair test (ROT) and computerized dynamic posturography test (CDP) in the patients with BLVF demonstrated by caloric test and others. Method : 400 vertigo patients were given VFT from June,1994 to October,1995. In the patients who had absent or reduced responses (total eye speed <10 degrees per second) in cold (17 C) water caloric testing or decreased responses in the range of lower fequencies during ROT, we evaluated their VFT results and clinical features. RESULTS: There were 38 cases out of total 400 patients(9.5%). Many patients with BLVF had rotational response magnitudes (at 0.04 Hz and above) that were within normal limits. CBP has shown vestibular dysfunction patterns in 32 patients. Hearing tests were normal in 9 cases and mixed hearing loss in 2 cases. Many patients experienced several episodes of acute vertigo with persistent imbalance; Only 4 patients complained of persistent oscillopsia. Viral infection (vestibuloneuronitis), immune reactions and toxic factors may play a role in the etiology of this rare BLVF. CONCLUSION: Our incidence of 9.5% is much higher than what was reported in the literature. Herb medications and frequent injections of aminoglycosides may be responsible for this higher incidence of BLVF. ROT is useful in detecting and predicting the remaining vestibular function in the BLVF patients.

The Rotating Chair Test in the Patients with Vertigo

OBJECTIVE: To show the value of rotating chair test (ROT) as an adjunct to the conventional electronystagmography (ENG) examination including caloric test for the diagnosis of vestibular lesions. BACKGROUND: Since caloric stimulatim is regarded as a very low frequency (0. 003Hz) test, it is desirable to test the function of horizontal semicircula canals by stimulating with faster frequencies. Baloh et al. (1984a) described that lesions ofdifferentiated by ROT. Leigh and Zee(1991) told that ROT can give more accurate and reproducible results than do caloric tests. METHOD: 30 patients who suffered from vertigo with either peripheral or central pathology were given computerized ENG and ROT. We discuss the representative examples of our initial experience with ROT. RESULTS: 1.In eight patients with known peripheral pathology, low-frequency phase deficits, asymmetry toward the lesim side and VOR suppression by gazefixation were seen during ROT. With bilateral peripheral vetibular disease, the ROT could identify remaining vestibular function at higher frequencies. 2. Seven patients with lesions of central vestibular structure showed abnormalities of saccades and pursuit during ENG and failure of VOR suppression by gaze fixation during ROT. 3. Out of 15 patients whose lesions could not be localized distinctly after caloric test, four patients were suggested to have central pathology. CONCLUSION: ROT can be a useful method to study the vestibular abnonnahties and an adjunct to the conventional ENG test.