Parkinson's is the second most common neurodegenerative disorder with progressive, disabling motor and non- motor symptoms for which effective symptomatic, but non disease-modifying treatment is available. Neuromelanin- containing neurons in the substantia nigra undergo neurodegeneration during Parkinson's disease. There is considerable heterogeneity in the progression of cell loss and clinical symptoms with major research interest in identifying prognostic subtypes.~A non-invasive biomarker that can track the loss of the neuromelanin-containing neurons would be highly desirable to (i) study subtype-specific trajectories of SN depigmentation, (ii) track disease progression in early Parkinson's to assist in stratifying groups and outcome assessment in clinical intervention trials, and (iii) enable patients and their families to better manage their condition including informed forward planning. Neuromelanin MRI (NM-MRI) is a new approach sensitive to the neuromelanin-iron complex, with proven association with the tissue changes of the number of the neuromelanin-containing neurons. Its diagnostic value was established in several studies case-control, but there is a lack of standardisation, multi-centre studies and prospective diagnostic trials. To date only a small, single arm retrospective study reported serial NM loss in Parkinson's.~Building on our previous work, the proposed research entails the development of an early progression biomarker for Parkinson's disease that is pathologically relevant, non-invasive, and uses MRI which is a widely available imaging method for detection. The experimental approach combines advanced computational imaging, retrospective use and extension of existing cohorts with a new dedicated prospective serial study using NM-MRI in uncertain parkinsonism, de novo and early Parkinson and healthy controls using latest MRI technology.
Prospective observational study to qualify NM-MRI as progression marker in early Parkinson's.