Deep Brain Stimulation (DBS) of the Subthalamic nucleus (STN) is an established treatment for patients with advanced Parkinson's disease (PD). STN DBS improves dopaminergic drug-responsive motor symptoms, thus allowing a reduction of post-operative drug dose. However, a considerable variation in the extent of dopaminergic drug reduction has been reported, with values ranging from 20% to 100%. Both L-dopa and DAs can be used, however, there are no formal studies examining which type of antiparkinsonian medication may be more effective and/or better tolerated following STN DBS.