Frontosubthalamic Networks in Parkinson's Disease.

This study is investigating how the brain circuits involved in impulse control function differently in Parkinson's disease patients who have impulse control disorders (such as compulsive gambling or hypersexuality) compared to those who do not. It uses a specialized brain imaging technique called MEG. **You may be eligible if...** - You have been diagnosed with Parkinson's disease - You have had a brain stimulator (deep brain stimulation/DBS) implanted in the subthalamic nucleus as part of your care - You are willing and able to delay your morning Parkinson's medication by up to 4 hours for the study session - You are 18 or older **You may NOT be eligible if...** - You have a severe language barrier that prevents understanding study instructions - You have other implanted medical devices that could interfere with brain scanning - You have other neurological conditions besides Parkinson's disease - You are enrolled in another neurological clinical trial - You are unable to sit still in the brain scanner for the required duration Talk to your doctor to see if this trial is right for you.