Imaging Studies of Cognitive Impairment in Parkinson s Disease

Study Summary

Background: \- Parkinson's disease causes slow movements, stiffness, and tremor. It can get worse over time, and in some cases can lead to dementia. Researchers are interested in how dementia affects the brain in people with Parkinson's disease. They will study both people with Parkinson s disease and healthy volunteers. They will give tests of thinking and memory, and look at brain activity using imaging studies. This may provide more information on what parts of the brain are not working well in people who have dementia related to Parkinson's disease. Objectives: \- To use imaging studies to see what parts of the brain do not work well in people with dementia caused by Parkinson's disease. Eligibility: * Individuals at least 40 years of age who have Parkinson s disease. * Healthy volunteers at least 40 years of age. Design: * Participants will be screened with a medical history and physical exam. * This study requires two outpatient visits over 2 days. * Participants will have tests of thinking, memory, and concentration. They will answer questions and fill out questionnaires. The tests will also look at how quickly they can move and handle small objects. The tests will take about 3 hours. * Participants will have magnetic resonance imaging to study the brain. Functional MRI (fMRI) can show what parts of the brain are used when performing a task. Participants will respond to images on a computer screen during fMRI. * Treatment will not be provided as part of this study.