Combined STN and NBM Deep Brain Stimulation for Mild Cognitive Impairment in Parkinson's Disease

The goal of this clinical trial is to evaluate the safety and tolerability of a novel deep brain stimulation (DBS) of the Subthalamic Nucleus (STN) and Nucleus Basalis of Meynert (NBM) to treat cognitive and cognitive-motor symptoms in individuals with Parkinson\'s disease. The main question it aims to answer is: Is a combined deep brain stimulation approach targeting the STN and NBM with four DBS leads safe and tolerable for cognitive and cognitive-motor symptoms in individuals with Parkinson\'s disease with Mild Cognitive Impairment. Ten participants are anticipated to be enrolled. Participants will undergo a modification of the traditional STN DBS approach for motor symptoms of PD. In addition to the two leads placed within the STN, two additional leads will be placed with the NBM for treatment of cognitive and cognitive-motor symptoms. Novel stimulation patterns will be used within the NBM to target cognitive and cognitive-motor symptoms using an investigational software. Participants will be followed over two years while receiving this therapy with assessments at baseline and every six months. Assessments will include a combination of neuropsychological evaluations, cognitive assessments, motor tasks (including gait/walking), and questionnaires to evaluate the treatment. Two different surgical trajectories will be used, with half the cohort randomized to each group. This will allow comparison of the impact of surgical trajectory on the intervention.