Clinical Research Directory

Inclusion Criteria: Ages between 30 and 85 years, males or females; Diagnosed to be Parkinson's disease patients according to MDS Parkinson's disease diagnostic criteria; Disease history over 3 years; Hoehn and Yahr Stage less than or equal to 4 during the medication "on" time; Responsive to levodopa treatment (Maximum rate of improvement in MDS-UPDRS, part 3, is over 30%). Exclusion Criteria: Atypical Parkinsonian syndrome or secondary Parkinsonian syndrome; Accompanied with other central nervous system diseases; With other severe systemic diseases or dysfunction; With severe psychiatric disorders; Subjects are using hormone or cytotoxic drugs and cannot stop taking the drug during the trial; With cognitive disorders (MMSE\<24); With severe dyskinesia (MDS-UPDRS part 4, score in 4.1/4.2 ≥ 2); Subjects have undergone previous brain surgery; Subjects are long-term user of anticoagulant; Subjects have intracranial lesions which may affect the surgery or follow-up studies as assessed by imaging; Subjects are unable to undergo MRI or AV133 PET examination; Pregnancy or in preparation for pregnancy; Not suitable to participate in this clinical trial as assessed by the study investigators/physicians.