Saccadic eye movements in frontal lesion and posthemispherectomy in humans. An electro-oculographic study

This study was concerned with the assumed role that the frontal eye fields could play in the mechanisms of: the voluntary saccade optokinetic responses. Ten patients with frontal lobe tumors (8 unilateral, 2 bilateral) and two patients with a right hemispherectomy were studied. EOG and EEG were performed in the same session. Left and right voluntary saccadic potentials could be recorded in all cases, no matter where the frontal lesion was located. Minor differences in amplitude were observed between the fast eye movement to the lesion and to the normal side. Horizontal optokinetic responses to a moving drum were a constant finding in all cases. The frequency and amplitude of the fast component of the responses did not show substantial differences with the drum moving to the lesion or to the healthy side. Voluntary saccadic eye movements to the left and left horizontal optokinetic responses to a moving drum to the right, were recorded in the two cases with a right hemispherectomy. The hypothesis that considers frontal eye field as the pulse generator area for the voluntary or reflex saccadic eye movements is discussed.