Inclusion Criteria:
* Confirmed Parkinson's Disease
* Levodopa responsiveness for at least 12 months
* UPDRS Part 3 score of ≥25 points in the "off" state
Exclusion Criteria:
* History of brain surgery to treat Parkinson's Disease
* Any history of cerebral insult or central nervous system infection
* Atypical Parkinson's Disease
* Focal or lateralized neurologic deficits
* Evidence of significant medical or psychiatric disorders
* Cognitive impairment as defined by the Montreal Cognitive Assessment (MoCA) ≤ 20
* Beck Depression Inventory-II score of ≥ 20
View Inclusion and Exclusion Criteria at ClinicalTrials.gov