Exploring the Possible Beneficial Impact of Non-invasive and Invasive Neuromodulation on Freezing of Gait in Parkinson's Disease During Different Ambulatory Complexities: An Electrophysiological and fMRI Study

This study looks at the brain and body mechanisms behind freezing of gait — a common and dangerous symptom in Parkinson's disease where a person suddenly feels unable to move their feet while walking. It examines both non-invasive brain stimulation (such as focused ultrasound) and deep brain stimulation (DBS surgery) to understand how the brain controls movement and why it freezes. **You may be eligible if...** - You are 20–90 years old with a confirmed Parkinson's disease diagnosis - For focused ultrasound patients: at least one of your main Parkinson's symptoms (slowness, tremor, stiffness) is not well-controlled by medications - For DBS patients: you have had Parkinson's for over 5 years and respond to levodopa - Healthy adults aged 40–80 or young adults aged 21–44 may also participate as controls **You may NOT be eligible if...** - You have advanced heart failure or cancer with distant spread - Your Parkinson's is at its most severe stage (Hoehn and Yahr Stage 5) - You have severe dementia or major depression (for DBS candidates) Talk to your doctor to see if this trial is right for you.