Opposite effects of l-dopa and DBS-STN on saccadic eye movements in advanced Parkinson's disease

To assess the effects of l-dopa and deep brain stimulation of the subthalamic nucleus (DBS-STN) on saccadic eye movements in patients with Parkinson's disease (PD). Visually and internally guided horizontal saccades were evaluated using a saccadometer in 64 patients with advanced PD and 48 healthy controls. Forty-four pharmacologically treated patients were assessed in their “med-off” (OFF) and “med-on” (ON) status, whereas 20 DBS-STN treated patients were assessed in their “med-off, stim-off” (OFF) and “med-off, stim-on” (ON) status. In all PD patients the saccades in the OFF status were delayed, slower and smaller (p