title: Computerized rotational vestibular testing in normal subjects.
abstract: 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.
authors.affiliation: Department of Otolaryngology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Su
authors.forename: W Y
authors.initials: WY
authors.lastname: Chiou
authors.forename: P K
authors.initials: PK
authors.lastname: Weng
authors.forename: H W
authors.initials: HW
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012399:Rotation; D014722:Vestibule, Labyrinth / Q000502:physiology*