Modification of constant optokinetic nystagmus by vestibular stimuation.
Experiments were conducted to quantify the effect of a vestibular stimulation of known magnitude on a constant optokinetic nystagmus (OKN). Ten normal human subjects were tested with varying magnitudes of vestibular stimuli that were superimposed on a constant 30 degrees optokinetic stimulus. The gain of the vestibular system in the dark was 0.42 +/- 0.11, and the gain in the light during superimposition testing was 0.12 +/- 0.02. From these results, predictions were made that the degree of vestibular imbalance necessary to produce an asymmetric OKN would generate a spontaneous nystagmus in the dark, which would be equivalent to 20 to 30 degrees. Data from a large group of patients were used for corroboration of the results.
D000328:Adult; D004585:Electrooculography; D005133:Eye Movements; D005260:Female; D006801:Humans; D007759:Labyrinth Diseases / Q000503:physiopathology; D008297:Male; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000503:physiopathology*