This study is about understanding pain in Parkinson's Disease (PD). It looks at the brain's serotonin system using special imaging called Positron Emission Tomography (PET). Serotonin is a chemical that affects mood and pain. PD patients often experience pain, and this study aims to see how serotonin might be involved. **Positron Emission Tomography (PET)** is a scan that helps doctors see inside the body. It uses a special type of imaging called **[18F]-MPPF** to look at serotonin receptors in the brain. **5HT1A receptors** are places in the brain where serotonin binds. The study will compare PD patients with pain to those without, focusing on brain areas like the insula and cortex. Testing could show how serotonin is linked to pain in PD patients.
- This study involves a **single imaging session** which includes both PET and MRI scans.
- Participants must have stable PD treatment and meet specific health criteria.
- Participants need to provide informed consent and be willing to learn about any unexpected findings from brain imaging.