Clinical Implication of Dissociation between Subjective Visual Horizontal and Subjective Visual Vertical

Moon, Tae Hyun; Bae, Sung Hyen; Cho, Il Kwon; Suh, Myung Whan; Rhee, Chung Ku; Jung, Jae Yun

Abstract

BACKGROUND AND OBJECTIVES Subject visual vertical (SVV) and subject visual horizontal (SVH) is well known otolith function test. Patients with acute unilateral vestibular weakness fail to set the test bar within normal range in SVH/SVV showing abnormal deviation toward lesion side. In some cases, SVH and SVV are deviated towards different directions, and analysis of these findings is rarely reported. The authors analyzed correlation of SVH/SVV and other vestibular function tests in patients with various vestibular diseases.
MATERIALS AND METHODS
From April 2005 to July 2007, total 234 patients who had admitted for dizziness were enrolled. All patients were divided in two groups, non-dissociation group (n=215) and dissociation group (n=19). Correlation of SVH, SVV, Videonystagmography (VNG), the rotating chair test was compared.
RESULTS
8.1% of patients showed dissociation between SVH and SVV. Clinical features did not showed significant difference between groups. In non-dissociation group, SVH/SVV showed correlation with VNG, rotating chair test. However in dissociation group, VNG and rotating chair test revealed high rate of consistency with deviation of SVH than that of SVV. Also direction of SVH and dizziness had higher consistency (88.9%) than that of SVV (11.1%).
CONCLUSION
The SVH showed consistency with other vestibular function test and may be more reliable than SVV when the result is dissociated.