Adaptive Deep Brain Stimulation to Improve Motor and Gait Functions in Parkinson's Disease

Inclusion Criteria: * Ability to give informed consent for the study * Movement disorder symptoms that are sufficiently severe, in spite of best medical therapy, to warrant surgical implantation of deep brain stimulators according to standard clinical criteria * Patient has requested surgical intervention with deep brain stimulation for their disorder * No movement -elated abnormalities that suggest an alternative diagnosis or contraindicate surgery * Absence of significant cognitive impairment (score of 21 or greater on the Montreal Cognitive Assessment (MoCA), * Signed informed consent * Ability to comply with study follow-up visits for brain recording, testing of adaptive stimulation, and clinical assessment. * Age 21-75 * Diagnosis of idiopathic PD with duration of motor symptoms for 3 years or greater * Patient has undergone appropriate therapy with oral medications with inadequate relief as determined by a movement disorders neurologist. * UPDRS-III score off medication between 20 and 80 and an improvement of at least 30% in the baseline UPDRS-III on medication score, compared to the baseline off-medication score, and motor fluctuations with at least 2 hours per day of on time without dyskinesia or with non-bothersome dyskinesia. OR Patients with tremor-dominant PD (a tremor score of at least 2 on a UPDRS-III sub-score for tremor), treatment resistant, with significant functional disability despite maximal medical management * Patients with gait impairments: slowed gai…