Study Rationale:
Parkinson’s disease robs the brain of dopamine, a neurochemical needed for normal movement and cognition. A variety of imaging methods can be used to monitor the brain’s dopamine systems and assess how dopamine-producing neurons are damaged by Parkinson’s disease (PD). The purpose of this study is to compare two of these techniques: one method, called DaTScan, uses a radioactive tracer to highlight dopamine-containing neurons; the other is a noninvasive MRI that can detect the byproduct of dopamine metabolism.
Hypothesis:
We predict that the DaTScan and MRI techniques will differ in what they reveal about the loss of dopamine-producing neurons and how these results correlate with the cognitive and movement symptoms in early versus advanced Parkinson’s disease.
Study Design:
We will study 25 individuals with early to moderate Parkinson’s disease who show no significant cognitive impairment and 25 individuals with advanced Parkinson’s disease who are cognitively impaired. We will image the brains of these participants using both methods and measure their motor symptoms and cognitive performance. We will then compare these scans to one another and assess how they relate to the motor and cognitive symptoms in each participant.
Impact on Diagnosis/Treatment of Parkinson’s Disease:
DaTScan is currently used clinically, but the technique is costly, requires injecting a radioactive marker, and its results can be distorted by medications taken for Parkinson’s disease. If an MRI-based method captures similar information or is better at measuring disease progression at different stages, it could become a more cost-effective and versatile tool for both clinical diagnosis and therapeutic trial design.
Next Steps for Development:
If successful, the results from this initial study could be used as preliminary data to justify a larger study in which people with PD undergo repeated imaging at multiple time points. Such assessment could improve our approach to monitoring Parkinson’s progression, and could support the design of clinical trials that will accelerate development of new treatments.