Deep Brain Stimulation (DBS) for the Treatment of Parkinson's Disease

Key Inclusion Criteria: * Diagnosis of bilateral idiopathic PD (H\&Y ≥ 2) with a duration of PD ≥ 5 years. * Persistent disabling Parkinson's disease symptoms or drug side effects (e.g., dyskinesias, motor fluctuations, or disabling "off" periods) despite optimal medical therapy. * Able to understand the study requirements and the treatment procedures and provides written informed consent before any study-specific tests or procedures are performed. Key Exclusion Criteria: * Any intracranial abnormality or medical condition that would contraindicate DBS surgery. * Have any significant psychiatric condition likely to compromise the subject's ability to comply with requirements of the study protocol * Any other active implanted devices including neurostimulators and /or drug delivery pumps * Any previous thalamotomy, pallidotomy or subjects who have undergone a DBS procedure. * Have any significant medical condition that is likely to interfere with study procedures or likely to confound evaluation of study endpoints. * A female who is breastfeeding or of child-bearing potential with a positive urine pregnancy test or not using adequate contraception.