The main purpose of this study is to test the safety and efcacy (how well it works) of an experimental intervention called VY-AADC02 on the severity of PD. VY-AADC02 involves placing a gene in the brain that programs brain cells to produce an enzyme (protein) called AADC (aromatic amino acid decarboxylase) in patients with Parkinson's Disease.The study group to which you are assigned will be chosen by chance (like ipping a coin); this is known as randomization. Subjects who take part in this study will be randomized 1:1 to receive either treatment with the study product or a placebo surgical procedure. This means that you have a 50% chance to receive the study product. It is necessary to evaluate the benet of a new, experimental treatment by having a similar group for comparison (placebo). PD studies in the past have used a placebo surgery for this reason.Other than the surgical team, neither you nor the rest of the study team will know if you received the active treatment or placebo until the study has ended. This application is specific to the PET imaging portion of the study.

You may be eligible for this study if you meet the following criteria:

• Conditions: Medical Research
• Age: 99 years or below
• Gender: All