Study demonstrates that free-water provides a potential non-invasive progression marker of the substantia nigra region in the brain.
Parkinson’s disease is a CNS disorder that results from the loss of cells in various parts of the brain, including a region called the substantia nigra. The substantia nigra cells produce dopamine, a chemical messenger responsible for transmitting signals within the brain that allow for coordination of movement.
With no objective test or biomarker for Parkinson’s, there is a clear need to develop non-invasive markers of substantia nigra progression in Parkinson’s disease. This study’s authors had previously found elevated free-water levels in the substantia nigra for patients with Parkinson’s disease compared with controls in single-site and multi-site cohorts.
In this study, published in the journal “Brain”, they tested the hypotheses that free-water levels in the substantia nigra of Parkinson’s disease increase following 1 year of progression, and that baseline free-water levels in the substantia nigra predict the change in bradykinesia following 1 year.
The researchers conducted a longitudinal study in controls (n = 19) and patients with Parkinson’s disease (n = 25). Diffusion imaging and clinical data were collected at baseline and after 1 year. Free-water analyses were performed on diffusion imaging data using blinded, hand-drawn regions of interest in the posterior substantia nigra.
The results found that free water levels increases with progression of Parkinson’s disease, and predicts subsequent changes in bradykinesia and cognitive status over 1 year, thus demonstrating that free-water provides a potential non-invasive progression marker of the substantia nigra.
Longitudinal changes in free-water within the substantia nigra of Parkinson’s disease
Edward Ofori ,et al., DOI: http://dx.doi.org/10.1093/brain/awv136