Abstract 231, Date 1:00 pm, Sunday, February 20, 2005 (24 hours) Session : D16: Vestibular: Clinical
Symptom Expression During Virtual Reality Exposure
*Susan Whitney, Patrick J. Sparto, Larry Hodges, Joseph Furman, Mark S. Redfern
Background: The purpose of the study was to determine if full field virtual reality (VR) exposure results in different symptom profiles in persons with vestibular disorders and controls. Methods: Subjects consisted of 3 symptomatic persons with a vestibular disorder and 10 healthy controls. The vestibular disorder group consisted of 2 women (59, years) and 1 man (59 years). The control group consisted of 6 women and 4 men (mean age 41, range 22-5 years) Subjects performed 8 different head and eye coordination tasks, including: 20 deg eye saccades with head fixed, 100 deg gaze saccades, and gaze smooth pursuit. All eight tasks were performed on 6 different days, with each day denoting either a stationary (2 days) or moving background (4 days). The moving scenes were generated using a back-projected CAVE VR system that provided full-field antero-posterior motion. All subjects were asked to express their subjective units of discomfort (SUDS, 0 to 10 scale) and to complete the Simulator Sickness Questionnaire (SSQ, 16 items, 0 to 3 scale) after each 90-second trial. Responses were dichotomized into either a ÒnoÓ (score of 0) or ÒyesÓ (score greater than 0, i.e. they experienced some symptom) immediately following each VR exposure for the SUDS, total SSQ, and each of the 3 SSQ subscales (nausea, disorientation, and oculomotor). Results: There was a significant association between subject group and the proportion of ÓyesÓ responses (chi-square, p<0.001) for all measures. The percentage of trials in which some symptoms occurred in the control and vestibular groups (CON:VEST) were as follows: SUDS: (23%:55%); SSQ total: (29%:60%); SSQ nausea: (11%:26%); SSQ disorientation: (5%:36%); and the SSQ oculomotor: (2%:60%). Conclusion: Patients with vestibular disorders appear to experience more discomfort than controls during virtual reality immersion. Supported by NIH grants DC005384, DC05205 and DC0532