This study is exploring how a low dose of an anti-epileptic drug called **levetiracetam** can help with memory issues in people with **Parkinson's Disease (PD)**. Parkinson's Disease is a condition that affects the brain and movement. **Neuroimaging techniques** (special brain scans) will show how the drug affects certain parts of the brain, like the **hippocampal subfields**, which are involved in memory. The study compares brain activity in PD patients with and without memory problems and healthy older adults. This could help find out if certain brain activities can predict memory issues in PD.

Key Points:

• The study includes people with PD who have mild memory problems and those without, as well as healthy volunteers.
• Participants must be able to have an MRI (a type of brain scan) and not have conditions like dementia or severe kidney issues.
• The study aims to help guide future treatments targeting specific brain areas to improve memory in PD patients.