Parkinson's disease (PD) is a common neurodegenerative disorder in middle-aged and elderly individuals, with a global incidence of 2.0% among adults aged 65 and over. Its pathogenesis remains unclear, and effective preventive and therapeutic approaches are lacking. PD severely impairs patients' physical and mental health and quality of life, while also imposing a substantial burden on families and society. This study will enroll patients with idiopathic PD diagnosed in the Department of Neurology, Fujian Medical University Union Hospital, from 2026 to 2036 to establish a research cohort. Using a non-interventional design, participants will undergo long-term follow-up through regular clinical visits, scale-based assessments, imaging examinations, and biological specimen testing. Corresponding data will be collected to build a research platform, aiming to clarify the pattern of disease progression and identify early diagnostic biomarkers. All testing methods are safe and reliable and will not pose additional risks to patients.

This study will be conducted in strict compliance with ethical requirements. Prior to enrollment, patients will be fully informed of the study details and will voluntarily provide written informed consent. To mitigate the risk of privacy disclosure, measures including coded management, data encryption, and access restriction will be implemented throughout the study to protect participants' privacy, safeguard their legitimate rights and interests, avoid additional financial burdens, and ensure the study is conducted in a standardized manner.

I hereby pledge to protect the personal privacy of all study participants and respect their autonomy. The study will be conducted in accordance with the principles of the Declaration of Helsinki and the Ethical Review Measures for Life Sciences and Medical Research Involving Human Subjects.

Inclusion Criteria:

• The diagnosis of Parkinson's disease (PD) will be made according to the Chinese Diagnostic Criteria for Parkinson's Disease (2016) issued by the Parkinson's Disease and Movement Disorders Group of the Neurology Branch of the Chinese Medical Association, with confirmation by at least two neurologists. Eligible patients must meet all of the following criteria:

Definite diagnosis of parkinsonism; No absolute exclusion criteria for PD are present; At least 2 supportive criteria for PD are satisfied; No red flags suggestive of alternative diagnoses are present.

Exclusion Criteria:

• Patients meeting any of the following conditions will be excluded from the study:

Inability to complete assessments using the Unified Parkinson Disease Rating Scale (UPDRS); Inability to complete assessments using the Mini-Mental State Examination (MMSE); History of recurrent stroke causing stepwise deterioration of parkinsonian symptoms; Diagnosis of secondary parkinsonism or Parkinson-plus syndromes; History of recurrent head trauma or confirmed encephalitis; Presence of severe organ dysfunction; Presence of severe endocrine diseases; Presence of hematological disorders; Presence of autoimmune diseases; Current diagnosis of malignant tumors.

The study population consists of patients with idiopathic Parkinson's disease (PD) diagnosed at the Department of Neurology, Fujian Medical University Union Hospital in Southeast China, according to the 2016 Chinese PD Diagnostic Criteria. Eligible patients will be consecutively enrolled during the study period (2026-2035) and followed up prospectively for up to 10 years.