title: Rotation vectors of slow and quick phase of caloric nystagmus.
abstract: OBJECTIVE
  The purpose of this study was to elucidate the rotation axes of the slow and quick phase of the caloric nystagmus using the video-oculographic technique.
  
  
  METHODS
  Subjects were placed in a supine position and cold-water stimulation was applied to the right ear canal. The eye movements were recorded in complete darkness by a high-speed infrared CCD camera. The sampling time of the camera was 132Hz with 640×480 effective pixels.
  
  
  RESULTS
  The rotation vectors were calculated from the printed-out chart of the 3D analysis data of the caloric nystagmus. The directions of the rotation vector of the quick phase of the nystagmus were almost opposite to those of the slow phase. The average planer equations of the slow and quick phase of the nystagmus in all subjects were 0.399x+0.1477y-0.8656z=0 and -0.3970x-0.1940y+0.8559z=0, respectively.
  
  
  CONCLUSIONS
  We demonstrated that the slow phase and quick phase of the vestibular nystagmus are along with the same axes in human subjects.
authors.affiliation: Department of Otolaryngology, Nippon Medical School 1-1-5 Sendagi, Bunkyo-ku, Tokyo, Japan. t.yagi@nms.ac.jp
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yagi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Koizumi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sugizaki
mesh_terms: D000328:Adult; D053483:Eye Movement Measurements; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009760:Nystagmus, Physiologic / Q000502:physiology*; D012399:Rotation