Longitudinal Observation of Neurodegeneration in Parkinson's Disease Using Molecular Imaging and Blood Biomarkers

This is a single-center, prospective observational study of patients with moderate-to-advanced primary Parkinson's disease (PD). PD is the second most common neurodegenerative disease. Current clinical evaluation mainly depends on motor symptoms, and there is a lack of quantitative biomarkers that can dynamically show nigrostriatal neurodegeneration. This study aims to explore the changing pattern of neurodegeneration by combining ¹⁸F-DOPA PET imaging and blood biomarkers such as neurofilament light chain, alpha-synuclein, GFAP, Tau and inflammatory factors. Thirty-six eligible participants will be enrolled. At baseline, clinical scales, lab tests, blood collection and ¹⁸F-DOPA PET-CT will be performed. Follow-up assessments will take place at 6 and 12 months. The primary outcome is the change in ¹⁸F-DOPA PET measurements from baseline to 12 months. Secondary outcomes include changes in clinical rating scales and blood biomarkers over 1 year. Participants can receive standardized medication advice for PD during the study.

Inclusion Criteria: * Confirmed diagnosis of primary Parkinson's disease; * Age 21 to 75 years, no sex restriction; * Hoehn-Yahr (H\&Y) stage 3-4; * OFF-state MDS-Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS-III) motor score \> 33, with a positive Madopar challenge test (MDS-UPDRS-III improvement rate \> 30%); * Willingness to participate in the study and signed informed consent form. Exclusion Criteria: * Secondary parkinsonism / atypical parkinsonian syndromes; * Genetically confirmed Parkinson's disease; * Prior surgical treatment for Parkinson's disease; * Contraindications to ¹⁸F-DOPA PET-CT scanning, including but not limited to cardiac pacemakers/defibrillators, ferromagnetic metallic implants (excluding skull-based and cardiac devices with MRI safety approval); * Comorbid dementia, severe cognitive impairment, or severe psychiatric disorders.