The goal of this single-center prospective, randomized, open-label clinical trial is to compare the effectiveness of imaging-based DBS programming with threshold assessment-based DBS programming in patients with Parkinson's disease and motor response fluctuations. The main question the study aims to answer is: Is the improvement of motor symptoms in the OFF-drug phase following STN DBS for Parkinson's disease, using imaging-based DBS programming only, non-inferior to the improvement of motor symptoms following DBS programming with threshold assessment at six months follow-up? Participants will be randomized to imaging-based programming or to threshold assessment-based programming. The main clinical outcome is motor symptoms; secondary outcomes are level of physical disability and quality of life, among others.