Previous studies have shown that motor symptoms improve with DBS in PD. It is also know that DBS can have an effect on cognitive and psychiatric symptoms. However, in the studies completed so far, it has not yet been possible to conclusively assess the exact effect of the stimulation itself on various cognitive and psychiatric symptoms. In particular, there is currently no data on how the precise localization of stimulation at the target site-the subthalamic nucleus (STN)-affects cognitive and psychiatric symptoms. It is not yet clear whether electrical stimulation of the right subthalamic nucleus has different effects on cognition and mood than stimulation of the left subthalamic nucleus. The aim of this study is to investigate whether DBS of the left hemisphere affects cognition and mood differently than DBS of the right hemisphere.
