Evaluation of the utricular function with the virtual-subject visual vertical system: comparison with ocular vestibular-evoked myogenic potentials.

The subjective visual vertical (SVV) is the most frequently assessed modality of verticality perception and has been measured in a variety of clinical situations, including peripheral vestibular lesions. The main objectives are (1) to collect normative data of Virtual SVV™ from healthy subjects, and (2) to study the correlation between Virtual SVV™ and ocular vestibular-evoked myogenic potentials (o-VEMP) on healthy subjects. Forty-three healthy subjects were recruited. Air conduction (AC)-elicited oVEMPs and bone conduction (BC)-elicited oVEMPs were measured. BC stimuli were produced with a RadioEar B-81 High Output Bone Transducer. Virtual SVV™ were also measured. Virtual SVV™ data from our healthy subjects were consistent with previously published normative SVV data. Normal Virtual SVV™ data did not correlate with normal AC-elicited and BC-elicited oVEMPs. Virtual SVV™ data from our healthy subjects were consistent with previously published normative SVV data. Virtual SVV™ data from our 43 health subjects only had weak correlation with c-VEMP, AC-elicited and BC-elicited oVEMPs. These data serve as a baseline for a future study of patients with unilateral utricular dysfunction. The Virtual SVV™ can be an attractive substitute for traditional SVV in clinical settings.