Deep Brain Stimulation (DBS) for Parkinson's Disease International Study

Inclusion Criteria: 1. Indication of DBS for PD consistent with the country specific approved labeling. 2. Levodopa-responsive Parkinson's disease (UPDRS III ≥ 30% improvement on Levodopa challenge test). 3. Symptoms treatable by medications but not adequately controlled with medications (with persistent disabling symptoms, such as motor fluctuations, dyskinesia). 4. At least 22 years old. 5. Screening cranial MRI, performed within 12 months of entry into the study, that is normal or with a non-significant abnormality that does not present any incremental risks or concerns for the patient as a result of the DBS procedure. 6. Understand potential risk/benefit, consent to the study, study procedures, and agree to complete the study follow-up visits and comply with the study protocol requirements. Exclusion Criteria: 1. Secondary Parkinson's disease, atypical syndromes. 2. Previous stereotactic functional neurosurgery or ablative therapy (e.g., pallidotomy, subthalamotomy), surgical contraindications related to DBS. 3. Dementia (Mattis Dementia Rating Scale ≤ 130), major depression with suicidal thoughts (Beck Depression Inventory II \> 25), acute psychosis, active alcohol or drug abuse, terminal illness, and any major medical or psychological histories, diagnoses, conditions, or comorbidities that would interfere with participation in the study per the investigator's medical judgment. 4. Electrical or electromagnetic implant (e.g., Cochlear prosthesis, cardiac pacemaker). 5. Surgical or medical contraindications to DBS surgery or therapy (e.g., uncontrolled hypertension, advanced coronary artery disease). 6. Participation in a drug, device, or biologics trial within the preceding 30 days that may confound the study results. 7. Pregnant female.