University of Wisconsin–Madison

Longitudinal MRI Biomarkers in Parkinson’s Disease

August 2012 to October 2016

In Parkinson’s disease, a group of brain cells that make a signaling substance called dopamine die off. As the dopamine is lost, Parkinson’s patients develop not only tremor and stiffness but also subtle changes in thinking and behavior. Although we currently have methods for imaging dopamine cells, we do not fully understand how loss of these cells influences brain function and structure to give rise to symptoms. This study will evaluate thinking and behavior through a number of tests and questionnaires. Pictures of the brain will also be taken using Magnetic Resonance Imaging (MRI) over the course of 2 years. By comparing the tests of thinking and behavior to the pictures of the brain, we will be able to better understand how the brain changes we observe influence behavior, mood and Parkinson’s disease symptoms. In this study we will be using MRI to evaluate how connections between brain regions are altered by Parkinson’s disease, and how the alterations affect thinking. An MRI technique known as functional MRI or fMRI allows us to examine the brain “at work”, and how brain regions influence one another to form networks. Other MRI techniques allow us to examine indicators of brain health at a cellular level. The purpose of this study is to see to what degree these MRI techniques can help us understand how the function and structure the brain change as symptoms progress. By imaging the brain twice over two years, we can observe any changes that are taking place. We hope to understand how any detectable changes are related to Parkinson’s disease symptoms. A better understanding of how brain images reflect the development of the disease may lead to new “biomarkers”. Biomarkers are measures of a biological process, which may ultimately be used to evaluate the influence of new treatments on disease progression.

This project led by: Catherine Gallagher, MD