Validation of α-synuclein Modifications in Parkinson's dIsoRder Evolution

Participants' clinical histories will be reviewed at T0 (baseline) and T1 (24 months). They will also undergo a clinical assessment at T0 and T1. The assessments will be tailored based on whether the participant belongs to the PD or non-PD group, as outlined below: • MDS-UPDRS + H\&Y: Used to evaluate the neurological domain, applied to the PD group. • BERG: Used to assess balance and performance, applied to both PD and non-PD groups. • CIRS-G: Used to evaluate comorbidities, applied to both PD and non-PD groups. • PD-CRS: Used to assess cognitive function, applied to the PD group. • MMSE (temporal and spatial orientation only): Used to assess cognitive function, applied to both PD and non-PD groups. • PDQ-8: Used to evaluate quality of life, applied to the PD group. • PD-CFRS: Used for functional assessment, applied to the PD group. • GDS: Used to assess depression, applied to both PD and non-PD groups. Blood samples will be collected at T0 and T1, with 20 mL drawn per participant.