Longitudinal ultra-high field imaging in Parkinson’s Disease: Tracking the disease course.

Introduction: The diagnosis of Parkinson’s Disease (PD) is currently based on the assessment of clinical symptoms and monitoring these symptoms over time. However, the early diagnosis can be challenging and it is often not immediately recognised. PD is a heterogeneous disease with great variability in motor manifestations, cognitive functions, autonomic complaints, disease course and response to therapy. The underlying aetiology of this clinical heterogeneity in PD is still not well understood and at this moment we are not able to predict the individual disease course of a patient. During the past years it has become well-established that new paradigms in MR imaging may be able to serve as a valuable method in the diagnostic work-up of PD and new biomarkers may even predict the disease course. Most of these studies however, have been performed in small patient cohorts or with low MRI field strengths.
Study design: We will perform a longitudinal observational 7T MRI study in a large PD patient cohort and age-matched healthy controls (HC). All subjects will undergo a 7T MRI scan of the brain at baseline and after 2 and 4 years. Moreover, a blood sample for genetic testing will be collected at baseline. Furthermore, motor, cognitive, psychological and autonomic functions of the PD subjects will be assessed at baseline and each follow-up moment. Based on these clinical parameters, PD patients will be subdivided into different clinical subgroups. Our aim is to include 130 PD patients and 60 HC in this study.
Objectives: To confirm early and subtle MRI changes in PD patients which distinguish them from the healthy population and to create a diagnostic tool for neurologists based on these differences. Secondary objectives are to detect whether different clinical phenotypes of PD patients also show different imaging characteristics and to correlate MRI characteristics to clinical phenotype, genetic characteristics and progression of symptoms.

- It is possible to distinguish PD patients from HC based on a combination of ultra-high field MRI characteristics and Quantitative Susceptibility Maps (QSM).
- Different PD symptoms are caused by specific changes in different micro-circuits of the basal ganglia and related structures.
- The individual disease course of PD patients can be (partially) predicted by a combination of several different MRI characteristics.

T0: Baseline
T1: Follow-up after 2 years
T2: Follow-up after 4 years