Computerized rotational vestibular testing in normal subjects.
BACKGROUND
As an integral part of the contemporary vestibular testing battery, computerized vestibular rotational testing provides physiologic stimuli and quantitative evaluation of the vestibulo-ocular reflex function of the horizontal semicircular canals. Clinically, it is most commonly used in the sinusoidal harmonic acceleration test (SHAT) and velocity step test. Because the results for a given subject may vary when tested using different facilities, the purpose of this study is to establish the normative data for our laboratory.


METHODS
Fifty-six normal subjects underwent the SHAT and velocity step test. Three parameters of SHAT--gain, phase and symmetry--were measured and recorded at 0.02, 0.05, 0.09 and 0.10 Hz. In the velocity step test, the three parameters of postrotatory nystagmus-time constant, maximum slow component eye velocity and directional preponderance were measured and recorded.


RESULTS
The means +/- standard deviations of gain in the SHAT were 0.47 +/- 0.16 at 0.02 Hz, 0.50 +/- 0.16 at 0.05 Hz, 0.50 +/- 0.16 at 0.09 Hz and 0.53 +/- 0.17 at 0.10 Hz. The coefficient of variation for SHAT gain was 0.32. The time constant means and standard deviations in the velocity step test were 13.44 +/- 3.53 and 13.52 +/- 3.69 for clockwise and counterclockwise rotations, respectively.


CONCLUSIONS
We conclude that computerized rotational vestibular testing is precise.
Su
Y Y
YY
Department of Otolaryngology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
Chiou
W Y
WY
Weng
P K
PK
Wang
H W
HW
D000293:Adolescent; D000328:Adult; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012399:Rotation; D014722:Vestibule, Labyrinth / Q000502:physiology*