Hypometric saccades and low-gain pursuit resulting from a thalamic hemorrhage.

Saccadic and pursuit eye movements were measured in a patient with a right thalamic hemorrhage using an infrared reflection technique. Saccades were hypometric when directed away from the side of the lesion, and pursuit was low in gain, with many interposed saccades, when directed toward the side of the lesion. This eye movement pattern is similar to that observed in hemidecorticate patients. We postulate that the ocular abnormalities observed in our patients were secondary to an interruption of the efferent pathways from the right cerebral areas mediating saccadic and smooth-pursuit eye movements.