Correlations between MRI and Vestibular Function Test in Central Vestibular Disorder

ABSTRACT

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.