Bilateral subthalamic nucleus deep brain stimulation (B-STN DBS) is one of the most effective surgical treatments for PD patients suffering from levodopa-induced motor complications. The relatively low incidence of permanent adverse effects and the potential for neuroprotection and alteration of the natural course of PD suggest a highly favorable benefit-to-risk ratio of this procedure. Since neuroprotection is best applied early in the disease course when there are more surviving neurons, we believe that further investigation of this procedure is warranted. The proposed pilot study will provide the necessary data to substantiate the safety and tolerability of the procedure as well as provide data for the design of a full-scale, multicenter trial to investigate the hypothesis that B-STN DBS is a safe and effective treatment to slow the progression of PD.