Neuromelanin MRI: A Progression Marker in Early PD

Inclusion Criteria:

-Inclusion criteria for patients:

• For Parkinson's patients and early-onset Parkinson's:

1. Diagnosis of Parkinson's disease, based on UK Brain Bank criteria and made withinthe preceding 3 years ('recent onset cases'); or
2. diagnosed at under 50 years ('under 50 years cases')

• For clinical symptoms suspicious for a diagnosis of PD but clinical uncertainty withregard to a definite diagnosis:

1. clinical symptoms not meeting all of the required UK Brain Bank diagnosticcriteria for the diagnosis of PD; or
2. clinical features not typically associated with PD and therefore raising thepossibility of a different type disorder/movement disorder referred for a DaTSCANas part of the National Health Service (NHS) clinical diagnostic work-up toinvestigate a suspicion for a parkinsonian movement disorder-type disease, orreferred for a research DaTSCAN as part of existing N3iPD and PaMIR studies forthe diagnostic work-up to investigate a suspicion for a parkinsonian movementdisorder-type disease.

• Age ≥18 to <90years
• Being able and willing to provide informed consent Inclusion criteria for healthy controls:
• Age ≥18 to <90years
• Being able and willing to provide informed consent

Exclusion Criteria:

• Exclusion criteria for patients:

1. The patient has severe comorbid illness that would prevent full studyparticipation
2. The patient has features indicating another type of degenerative parkinsonism,e.g. progressive supranuclear palsy
3. Drug-induced parkinsonism (Drug-unmasked PD is allowed)
4. Symmetrical lower body parkinsonism attributable to significant cortical and/orsubcortical cerebrovascular disease (patients with 'incidental' small vesseldisease on brain imaging are allowed).
5. Negative or normal functional imaging of the presynaptic dopamine system
6. The presence of UK Brain Bank exclusion criteria will be recorded at baseline,allowing for the presence of 1 or 2 exclusion criteria (e.g. dopamine antagonistDrug used; more than one affected relative) (if justified e.g. by abnormalSPECT).
7. Any contraindication to Magnetic Resonance (MR) scanning.
8. Any major neurological (other than PD), psychiatric or cardiovascular disease orhistory of brain injury.
9. Medical illness or medication that may affect brain morphometry or function.
10. Patient who is pregnant and/or breastfeeding. Exclusion criteria for healthy controls:
11. Subject has severe comorbid illness that would prevent study participation
12. Subject already has a diagnosis of Parkinson's disease
13. Any contraindication to Magnetic Resonance (MR) scanning
14. Subject who is pregnant and/or breastfeeding.