Horizontal and vertical optokinetic nystagmus (OKN) and optokinetic after-nystagmus (OKAN) were studied in 17 normal subjects who were positioned either upright or laterally tilted 90°. OKAN responses were observed in 15 of 17 subjects; horizontal OKAN asymmetry was found in 5 of 15 subjects. Static lateral tilt produced an increase in downbeat vertical OKAN (VOKAN) response and no change in horizontal OKAN (HOKAN) response. Tilt did not produce changes in either horizontal or vertical OKN. The finding of modulation of VOKAN with head tilt in humans suggests a potential test for otolith-canal interaction.
Get full access to this article
View all access options for this article.
References
1.
RaphanTMatsuoVCohenB: A velocity storage mechanism responsible for optokinetic nystagmus (OKN), optokinetic after nystagmus (OKAN) and vestibular nystagmus.InBakerRBerthozA editors: Control of gaze by brain stem neurons. Amsterdam, 1977, Elsevier Publishing Co, pp 37–47.
2.
CohenBHennVRaphanTDennettD: Velocity storage, nystagmus, and visual-vestibular interactions in humans. Ann NY Acad Sci374: 421–433, 1981.
3.
KoenigEDichgansJ: Aftereffects of vestibular and optokinetic stimulation and their interaction. Ann NY Acad Sci374: 434–445, 1981.
4.
ZeeDSYeeRDRobinsonDA: Optokinetic responses in labyrinthine-defective human beings. Brain Res3: 423–428, 1976.
5.
IrelandDJJellRM: Optokinetic after-nystagmus in man after loss or reduction of labyrinthine function—A preliminary report. J Otolaryngol11: 86–90, 1982.
6.
MatsuoVCohenB: Effect of static head position on the duration of vertical optokinetic after nystagmus (OKAN) in monkeys. Neurosci Abstr7: 39, 1981.
7.
DichgansJJungR: Oculomotor abnormalities due to cerebellar lesions.InLennerstrandGBach-Y-RitaP editors: Basic mechanisms of ocular motility and their clinical application. New York, 1975, Pergamon Press, pp 281–298.
8.
BalohRWHonrubiaVSillsA: Eye tracking and optokinetic nystagmus: Results of quantitative testing in patients with well defined nervous system lesions. Ann Otol Rhinol Laryngol86: 108–114, 1977.
9.
LisbergerSGMilesFAOpticanLMEighmyBB: Optokinetic response in monkey: Underlying mechanisms and their sensitivity to long-term adaptive changes in vestibuloocular reflex. J Neurophysiol45: 869–890, 1981.
Holm-JensenSPeitersenE: The significance of the target frequency and the target speed in optokinetic nystagmus (OKN). Acta Otolaryngol88: 110–116, 1979.
