title: Use of a visual guide to improve the quality of VOR responses evoked by high-velocity rotational stimuli.
abstract: High-velocity rotational stimuli have the potential to improve the diagnostic capabilities of clinical rotation testing by revealing nonlinear vestibulo-ocular reflex (VOR) responses that are indicative of asymmetric vestibular function. However, eye movements evoked by high-velocity rotations often are inconsistent over time and therefore do not yield reliable diagnostic measures. This study investigated whether use of a novel "visual guide" could improve the consistency and quality of VORs obtained during testing with pulse-step-sine (PSS) stimuli providing periodic high-velocity, horizontal-plane rotations with peak velocities up to 290 deg/s. The visual guide (narrow phosphorescent line spanning 180 degrees field of view) was mounted horizontally on the rotation chair at the subject's eye level. Eight healthy human subjects were tested either in complete darkness while performing an alerting task, or while viewing the visual guide in an otherwise dark room. We found that the visual guide improved the quality of VOR responses as shown by an increased proportion of slow-phase velocity data segments retained for analysis, by a decreased variance of the processed eye velocity data, and by a reduction of outlying VOR response measures. We also found that the visual guide did not induce visual suppression because VOR gain measures were not diminished.
authors.affiliation: Neurological Sciences Institute, Oregon Health & Science University, Portland, Oregon 97006, USA.
authors.forename: Claire C
authors.initials: CC
authors.lastname: Gianna-Poulin
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Peterka
mesh_terms: D000328:Adult; D000465:Algorithms; D002498:Centrifugation; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009039:Motion Perception; D009759:Nystagmus, Pathologic / Q000150:complications / Q000517:prevention & control*; D012016:Reference Values; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D018709:Statistics, Nonparametric; D014724:Vestibular Function Tests / Q000379:methods*; D014722:Vestibule, Labyrinth / Q000502:physiology*
references.citation: J Vestib Res. 2005;15(5-6):291-311
references.pmid: 16614475
references.citation: J Vestib Res. 2004;14(5):387-91
references.pmid: 15598993
references.citation: Otol Neurotol. 2003 Jul;24(4):633-6
references.pmid: 12851557
references.citation: J Vestib Res. 2005;15(1):49-58
references.pmid: 15908740
references.citation: Acta Otolaryngol. 2004 Jun;124(5):587-94
references.pmid: 15267177
references.citation: J Vestib Res. 1990-1991;1(1):49-59
references.pmid: 1670137
references.citation: Aerosp Med. 1963 Feb;34:124-9
references.pmid: 14022387
references.citation: Brain Res. 1981 Oct 5;222(1):159-65
references.pmid: 7296263
references.citation: Exp Brain Res. 2003 Oct;152(3):383-92
references.pmid: 12920495
references.citation: Acta Otolaryngol. 1989 Jul-Aug;108(1-2):1-8
references.pmid: 2788346
references.citation: J Laryngol Otol. 1996 Dec;110(12):1133-7
references.pmid: 9015425
references.citation: Neurology. 1997 Apr;48(4):916-20
references.pmid: 9109877
references.citation: Acta Otolaryngol. 2004 Jan;124(1):36-40
references.pmid: 14977076
references.citation: J Vestib Res. 1990-1991;1(1):61-71
references.pmid: 1670138
references.citation: Exp Brain Res. 1994;101(3):525-8
references.pmid: 7851520
references.citation: J Vestib Res. 1999;9(2):135-44
references.pmid: 10378185
references.citation: Otol Neurotol. 2006 Jun;27(4):535-41
references.pmid: 16791046
references.citation: Acta Otolaryngol Suppl. 1995;519:234-7
references.pmid: 7610877