Effectiveness and Safety of Directional Deep Brain Stimulation for Parkinson's Disease

Inclusion Criteria:

1. Age at the time of enrollment: 18 ~ 75;
2. Idiopathic Parkinson's disease;
3. Patient whose symptoms are not adequately controlled by best medical therapy;
4. Hoehn and Yahr stage≥2.5;
5. Patient whose symptoms are improved by at least 30% with levodopa challenge test;
6. Must be an appropriate candidate for the surgical procedures required for bilateralDBS;
7. Is willing and able to comply with all visits and study related procedures;
8. Patient understands the study requirements and the treatment procedures and provideswritten informed consent before any study-specific tests or procedures are performed.

Exclusion Criteria:

1. Had received lesioning surgical treatment;
2. A female who is breastfeeding or of child-bearing potential with a positive urinepregnancy test or not using adequate contraception;
3. Any current drug or alcohol abuse;
4. Cognitive impairment (MMSE≦17 for primary school education or MMSE≦24 for middleschool education and above);
5. Any significant psychiatric problems, including unrelated clinically significantdepression;
6. Any history of craniocerebral injury, tumor, or severe cerebrovascular disease;
7. Severe brain atrophy (confirmed by CT or MRI);
8. A condition requiring or likely to require the use of diathermy;
9. Abnormal blood routine or biochemical test, coagulation dysfunction, serious abnormalliver or kidney function;
10. Uncontrolled high blood pressure, serious heart disease or serious medical orrespiratory diseases;
11. Long-term of immunosuppressive or hormone therapy;
12. Other diseases requiring the stimulators;
13. A condition requiring or likely to require the use of MRI;
14. Participated in any other clinical trials within the preceding 3 months;
15. Unwilling or unable to cooperate with the implantation of DBS system;
16. Unwilling or unable to cooperate with postoperative follow-up;
17. Not considered to be applicable by the investigator.