Table 1.

VOR parameters and measures of vestibular disability

Test/Subject	Normal	VS
VOR Sinusoids
Gain	0.67 ± 0.11	0.59 ± 0.14
Time constant, s	19.8 ± 5.2	10.5 ± 4.9
Bias, deg/s	−0.59 ± 5.1	1.14 ± 6.6
VOR head impulses
Gain	0.88 ± 0.1	0.71 ± 0.2
Variability, deg/s	11.3 ± 6.5	17.7 ± 6.6
Vestibular disability
DHI	1.7 ± 3.0	22.1 ± 17.8
FGA	29 ± 0.7	24.0 ± 4.2

Means ± 1 standard deviation for the normal and vestibular schwannoma (VS) subjects for the vestibulo-ocular reflex (VOR) parameters derived from sinusoidal rotations and head-on-body impulsive rotations, and for the measures of vestibular disability [DHI, subjective dizziness scaled from 0 (normal) to 100; FGA, gait and balance dysfunction scaled from 0 to 30 (normal)]. for sinusoidal VOR bias, positive values were toward the tumor ear in patients with VS and toward the right in normal subjects. Normal distributions were confirmed for all measurements using the Shapiro–Wilk test (P > 0.05 for all variables), and all comparisons between normal and VS subjects were significant (P < 0.05) except for the sinusoidal gain (P = 0.06). DHI, Dizziness Handicap Inventory; FGA, Functional Gait Assessment.