Vertical saccades in brain stem disorders.

Mean peak velocity and accuracy of vertical saccades were measured in 15 patients with disorders in the brain stem and in 12 normal subjects. (1) In the normal group up-directed saccades were faster than down-directed and the velocity of the saccade was not dependent on the age of the subject. Up-saccades were faster whether electro-oculography or photo-electro-oculography were used. (2) In patients with brain stem disorders the velocity of vertical saccades did not significantly differ from the saccadic velocity in the normal group. This is in contrast to what was found in horizontal saccades, where a reduced velocity was characteristic.