Abstract
The measurement of subjective visual vertical (SVV) is clinically used as a method to assess the degree of dysfunction in the otolith, primary vestibular nerves, and central graviceptive pathways. We measured the SVV in patients with vestibular neuritis (VN) and unilateral sudden deafness (uSD). The purpose of this study was to demonstrate the characteristics of SVV in patients with VN and uSD, and determine the relation between the SVV and other neuro-otological examinations, including vestibular evoked myogenic potentials (VEMP) and the caloric test.
The SVV was measured in 25 patients suffering from VN (9 women, 16 men aged from 27 to 76 years) and 30 patients suffering from uSD (16 men and 14 women aged from 21 to 76). The SVV was tilted>2o in VN (64.0%) and in uSD (23.3%). Among the abnormal SVV patients (SVV>2o), the tilt was directed toward the affected ear in all VN patients and in 75% of uSD patients.
Concerning the caloric test and VEMP in VN patients, there were no significant relationships between the percentages of abnormal SVV and the degree of canal paresis and VEMP. In uSD patients, abnormal VEMP patients tended to show an abnormal SVV. Our results suggest that the shift of the SVV was strongly affected not only by superior vestibular nerve lesions, but also by inferior vestibular lesions.
