Emotional and Cognitive Subthalamic Nucleus in Deep Brain Stimulation Treated Parkinson Patients

About 300 patients with Parkinson's disease (PD) have been successfully treated by deep brain stimulation (DBS) during the last 10 years in Hadassah. In most of the patients the site of stimulation is the subthalamic nucleus (STN). Recent studies by our group and others have demonstrated that the STN is divided into motor and non-motor areas. The investigators have recently shown that electrophysiological mapping of the STN during the surgery can differentiate motor and non-motor areas of the STN. Existing methods of adjustment of DBS parameters aim at amelioration of the motor signs and therefore with inactivation of the STN motor territory only. Although the DBS parameter setting is believed to influence the mental and cognitive states, there is no data that correlates stimulation parameters with mental and cognitive state. In addition, DBS parameter setting is also believed to influence important verbal functions which are partially related to motor, mental and cognitive states, but no data correlates the verbal function with the DBS stimulation parameters. The investigators hypothesize that the cognitive areas of the STN have distinct electrophysiological properties similar to our findings with the limbic / mental areas of the STN. The investigators further hypothesize that specific stimulation of these cognitive areas can influence the cognitive state and thus treatment with cognitive-adjusted DBS can improve the cognitive symptoms of PD. In this project, the investigators intend to map the motor, emotional and cognitive areas of the STN using neuronal (single units) responses to emotional voices and cognitive tasks and to identify the emotional and cognitive spectral signature of the STN single unit activity using spectral analysis and neuronal responses to emotional voices and cognitive tasks. In addition the investigators intend to find the neuronal signature of speech and to find the correlation between motor, mental and limbic electrophysiology to speech