Stimulation Parameters and Non-motor Symptoms in PD Treated With DBS

Pre- and post- DBS implantation brain scans will be reviewed by the study team to see if
patients' DBS settings can be personalized. If so, study subjects will undergo adjustments to
their DBS settings and be asked to perform cognitive tests. Some patients will be asked to
come back for a second visit for brain scans.

Inclusion Criteria:

1. Between 40 and 70 years of age,

2. Ability to provide informed consent,

3. Clinical diagnosis of idiopathic Parkinson disease (PD) by a movement disorders
neurologist,

4. Disease duration of at least 4 years,

5. Treated with bilateral STN DBS for at least 3 months prior to study enrollment.

Exclusion Criteria:

1. History of prior neurosurgical intervention for PD (e.g., DBS, thalamotomy,
pallidotomy)

2. History of other central nervous system disease (excluding migraine),

3. Presence of active psychiatric symptoms meeting Diagnostic and Statistical Manual of
Mental Disorders-4th Edition (DSM-IV) criteria for Axis-I disorder on formal
psychiatric evaluation, with the exception of mild depression (Beck Depression
Inventory-2 score below 19),

4. Cognitive impairment meeting Diagnostic and Statistical Manual of Mental Disorders-4th
Edition (DSM-IV) criteria for dementia on formal neuropsychological evaluation,

5. Current alcohol or substance abuse,

6. Lack of fluency in English which would invalidate cognitive testing,

7. Hearing or visual impairment precluding cognitive testing.

Exclusion criteria for Day 2 procedures:

8. Inability to safely undergo MRI procedure (i.e., metal objects like prostheses,
pacemakers)