Eye Movements in Brainstem Lesions

The eye movements of 10 patients with brainstem lesions were examined, using an electro-oculo-graphic technique. An analysis was made of the responses in the following tests: smooth pursuit, saccade, rotation, optokinetic, optovestibular and caloric. Chief interest was directed towards the peak velocity. The results were compared with the corresponding velocities in 20 normal subjects. In the same patient, one or several types of eye movements could be normal, while others were pathological. In the whole group, voluntary eye movements (smooth pursuits and voluntary saccades) were more vulnerable than reflexive ones (nystagmus). Next to the smooth pursuit test and the voluntary saccade test, the optovestibular test was the most sensitive in discriminating patients with brainstem lesions from normal subject.