Abstract
The vertical and horizontal optokinetic nystagmus in human subjects were compared with their occurence. The tests were performed in 20 normal subjects and 28 cases suffered from vertigo and ataxia using the rotary drum of Bárnáy's type. The optic drum was worked electrically with three constant speeds of 16, 33 and 45 rotations per minute. The optic elicit nystagmus were investigated by electronystagmographic recording and their abnormalities were discussed. Frequency and total amplitude of nystagmus in each component for 10 seconds were employed as the indications of optokinetic reaction.
The results were as follows:
1) The vertical nystagmus appeared favorably and its occurence was comparable in number as well as amplitude to that of the horizontal nystagmus. Generally in vertical component the intensity of the up-beating nystagmus become stronger than low-beating one.
2) In the cases of labyrinthine disorders including Ménière's disease, the value of optokinetic nystagmus test for clinical diagnostic purpose were little.
3) Almost cases of lesions of central nervous system showed the disturbance on occurence of vertical nystagmus, and some cases showed DP-phenomenon or reduced reaction only in vertical component. Our vertical nystagmus test by Bárány's method is one of the important clinical test of vertigo and disturbance of equilibrium.
