Abstract

Background and Objectives: There are known parameters that indicate vestibular asymmetry, such as directional preponderance (DP) on caloric test, asymmetry on slow harmonic acceleration (SHA) test, asymmetry of time constant (Tc) and slow cumulative eye position (SCEP) on velocity step test. Aim of this study is investigate the sensitivity and predictability of the vestibular asymmetry parameters among them. Materials & Methods: Twenty six patients who were diagnosed as acute unilateral peripheral vestibulopathy were enrolled in this study. We compared each parameter with site of lesion based on the direction of spontaneous nystagmus and canal paresis (CP) which were totally correlated in this group of patients. Results: Positive predictability of each parameter showed 58% in DP, 62% in SHA asymmetry, 62% in SCEP, 38% in Tc. In the cases that each parameter showed positive result, all of DP and SHA asymmetry indicated site of lesion, and showed high correlation coefficient(r=0.89). But in 27% of SCEP and 23% of Tc did not indicate site of lesion. Conclusion: All parameters showed low sensitivity for identifying laterality of lesion even the tests were performed with in one week after vertigo attack. DP and VOR asymmetry showed high positive predictability for indicating lesion site.

• Keywords: Vestibular function test;Vestibular neuritis;Vestibulopathy;