This study is designed to explore a new treatment option for motor symptoms in people with Parkinson's disease. Motor symptoms and gait disturbance for Parkinson's are often disabling and can increase risk of falls and requce quality of life. We are testing whether a non-invasive brain stimulation technique called transcutaneous auricular vagus nerve stimulation (taVNS) is tolerable, acceptable and can be administered at-home and used to improve symptoms of Parkinson's disease. TaVNS delivers electrical impulses through the skin of the ear to the vagus nerve which research has shown modulates brain activity. The purpose of this research is to see whether this treatment approach is feasible, tolerable and and potentially effective at treating the symptoms of Parkinson's disease. If successful, this research study will hopefully lead to a larger study in the future where the efficacy of the treatments can be studied.

The purpose of this research study is to learn how Deep Brain Stimulation (DBS), which targets a part of the brain called the subthalamic nucleus (STN), may affect thinking and memory in people with Parkinson's Disease (PD). We plan to include about 55 people with PD who have already had DBS surgery at MUSC's Clinical DBS Program.

As part of the study, participants will attend two visits after their DBS surgery. The first visit, which will last about three hours, includes going over the study information and consent form, collecting background information (demographics), and completing tests that measure thinking and memory (cognitive assessments) and speech. The second visit, also about three hours, will involve an MRI scan to look at how the brain's networks change when the DBS device is turned on and off. Participants have the option to combine visits 1 and 2. Participant's will also be invited to undergo an optional second scan. If participants consent, the second scan will be performed on a separate day than the first scan and therefore, there will be a total of 3 study visits.

These findings may help doctors and researchers make better decisions about which patients are most likely to benefit from DBS surgery and how to choose the best stimulation settings to reduce unwanted changes in thinking and memory.

The objective of this research study is to identify brain biomarkers using MRI scans that can predict an individual's response to Deep Brain Stimulation (DBS). A total of 55 participants with Parkinson's Disease planning to undergo DBS will be recruited from MUSC's Clinical DBS Program. Participants will undergo two visits which include a 2.5-hour pre-DBS questionnaire and MRI scanning visit, and a 3.5-hour post-DBS cognitive assessment visit. In addition control participants without Parkinson's Disease will be recruited to undergo MRI scanning and cognitive assessments.