Parkinson's Disease

Inclusion Criteria:

1. Diagnosis of bilateral, idiopathic PD with clinically significant motor fluctuations despite maximized antiparkinsonian therapy. This will be based on medical history, neurologic examination (the presence of at least 2 of the following: resting tremor, rigidity, or bradykinesia), and response to antiparkinsonian therapy.
2. At least 5 years' duration, relative to the date of surgery, since diagnosis of PD.
3. Age >21 inclusive, on date of surgery.
4. The subject is ambulatory in their best on time (not wheelchair bound).
5. The subject is medically able to undergo the surgery as determined by clinical and laboratory evaluations and any other evaluations that are part of the standard practice at the institution in which the subject is to undergo surgery (e.g., subjects will have normal coagulation tests and normal platelet levels).
6. The subject is expected to be able to comply with and understand the required visit schedule and all required tests and procedures.
7. Signed IRB-approved informed consent is obtained before any study-specific procedure, including assessments required during the eligibility evaluation period.

Exclusion Criteria:

1. In the judgment of the investigator, a history of any clinically significant medical, psychiatric, or laboratory abnormality for which participation in the study would pose a safety risk to the subject.
2. History of treatment of PD by any procedure involving intracranial surgery or implantation of a device.
3. MRI of the brain within 12 months before the surgery which demonstrates an intracranial abnormality that would contraindicate surgery (e.g. stroke, tumor, vascular abnormality affecting the DBS target area).
4. Any disorder that precludes a surgical procedure (e.g., signs of sepsis or inadequately treated infection) or alters wound healing.
5. Receipt of antiplatelet agents for at least 10 days prior surgery.
6. A score of less than or equal to 24 on the Folstein Mini-Mental examination performed during the eligibility evaluation period.
7. History of significant psychiatric illness, epilepsy, or Alzheimer's disease.
8. Active drug or alcohol abuse.
9. Pregnancy or lack of effective contraception in women of childbearing potential defined as one year post-menopausal or surgically sterile.
10. Treatment with nonantiparkinsonian agents (e.g., atypical neuroleptics) that may affect symptoms of PD within 60 days before entering the study.
11. Any medical disability (e.g., severe degenerative arthritis, compromised nutritional state, severe peripheral neuropathy) that would interfere with the assessment of safety and efficacy in this trial.
12. Inability to follow-up with post-operative study visits

Dystonia Inclusion Criteria

1. Idiopathic or secondary dystonia diagnosed by a movement disorders neurologist
2. Significant functional impairment despite optimal medical management, including failed botulinum toxin therapy if appropriate
3. Age >7 years inclusive, on date of surgery.
4. The subject is medically able to undergo the surgery as determined by clinical and laboratory evaluations and any other evaluations that are part of the standard practice at the institution in which the subject is to undergo surgery (e.g., subjects will have normal coagulation tests and normal platelet levels).
5. The subject is able to comply with and understand the required visit schedule and all required tests and procedures.
6. Signed IRB-approved informed consent is obtained before any study-specific procedure, including assessments required during the eligibility evaluation period.

Exclusion Criteria

1. Patients considered at high risk for elective neurosurgery because of co-morbid conditions
2. Pregnancy
3. Inability to follow-up with post-operative study visits