The purpose of this study is to evaluate the utility of a portable motion sensor-based system designed to assist with deep brain stimulation (DBS) programming sessions for Parkinson's disease patients.

Inclusion Criteria:

• Hoehn and Yahr stage 2 or worse when off medications
• Average tremor and/or bradykinesia Unified Disease Rating Scale (UPDRS) score greater than 2 off meds
• L-dopa responsive with clearly defined "on" periods, UPDRS motor III average tremor and bradykinesia improves by 25%
• Stable on medical therapy for at least one month prior to study enrollment
• Clinical approval to undergo unilateral DBS surgery targeting the STN or GPi
• Available to participate for six months following DBS surgery

Exclusion Criteria:

• "Parkinson's plus" syndromes, secondary, or atypical Parkinson's syndromes (e.g. progressive supranuclear palsy, striato-nigral degeneration, multiple system atrophy, post-stroke, post-traumatic, or post-encephalitic Parkinson's. These patients have cardinal symptoms characteristic of PD but with additional symptoms indicating other organic brain dysfunction, such as gaze palsies, autonomic dysfunction, lack of response to L-dopa, these individuals tend not to improve with standard treatments for PD)
• previous Parkinson's Disease surgery
• medical contraindications to surgery or stimulation (e.g. uncontrolled hypertension, advanced coronary artery disease, other implanted stimulation or electronically-controlled devices including cardiac demand pacemaker, aneurysm clips, cochlear implants, or a spinal cord stimulator) (Note: for the subject who receives either a pacemaker and/or defibrillator after this study enrollment, he/she will be allowed to continue the study if the neurostimulator system can be adequately programmed to permit system compatibility)
• contraindication to magnetic resonance imaging (e.g. indwelling metal fragments or implants that might be affected by MRI)
• neuropsychological dysfunction (e.g. dementia) that would contraindicate surgery
• intracranial abnormalities that would contraindicate surgery (e.g. stroke, tumor, vascular abnormality affecting the target area)

Parkinson's disease