Subthalamic Deep Brain Stimulation (DBS) in Parkinson's Disease
Condition: Parkinson's Disease
MeSH terms: Parkinson Disease
Study type: Interventional
Phase: Early Phase 1

Summary: 
      The purpose of this study is to examine the brain changes in people with Parkinson's Disease
      (PD) after they get deep brain stimulation (DBS) surgery, compared with people who do not
      have Parkinson's Disease. Treatment of Parkinson's disease is often difficult and
      challenging. Deep brain stimulation is an established surgical treatment that is effective
      for the treatment of PD, but the details of why it helps are not known. In order to achieve
      maximum benefits from this treatment, it is important to understand how it changes the brain.
      Specifically, the investigators will study electrophysiology, which is the study of how the
      brain conducts electrical messages to the rest of the body. To do this, the investigators
      will use transcranial magnetic stimulation (TMS), which is a painless and non-invasive
      procedure. They will also conduct motor physiology experiments of the upper and lower limbs
      to collect data about skeletal muscle movement. The data from this study will help explain
      whether the electrical changes in the brain have any relation to the physical benefits
      patients with Parkinson's Disease sometimes receive from DBS surgery.
    

Detailed description: 
      Screening evaluation: The Investigators will ask questions to see if the participant
      qualifies to be in the study. The screening visit will occur up to 4 months before the first
      study visit, and can be scheduled to occur on the same day as the first study visit. This
      evaluation will include a review of medical history and clinical findings related to
      Parkinson's Disease (if applicable). There may be a neurological exam (physical exam). Women
      of child bearing potential will take a urine pregnancy test. If applicable, the medications
      currently used to treat Parkinson's Disease symptoms will be reviewed and subjects will be
      asked to discontinue them for some hours on the days of the study visits. The investigators
      do not expect concerns or unwanted consequences arising either from discontinuing the
      Parkinson's Disease medications or turning off the DBS stimulator for the duration of time
      proposed in the study.

      Participants will be studied under 4 conditions, over a span of as few as two days to as long
      as two months. The four Conditions are : 1) The DBS stimulator will be turned OFF for both
      sides. 2) The DBS stimulator will be turned ON for the right side. 3) The DBS stimulator will
      be turned ON for the left side. 4) The DBS stimulator will be turned ON for both sides. The
      order of these conditions will be picked randomly.

      Participants will be asked not to take PD medications for approximately 12 hours prior to the
      scheduled visit time, and until after the physiological testing.

      Healthy controls will be studied on only one occasion, as they do not have DBS.

      Tests performed for each study condition:

        1. Parkinson's Participants Only: A neurological examination will be performed by
           administering several clinical scaled. These clinical scales include the Unified
           Parkinson's Disease Rating Scale (UPDRS), the self-report Parkinson's Disease Quality of
           life scale (PDQ-39), MMSE instrument for cognitive (or memory) testing, and Beck
           Depression Inventory (BDI II) for evaluation of mood and depressive symptoms. The
           PDQ-39, MMSE, and BDI will each only be administered once and therefore will not be
           repeated at every study visit.

        2. The investigators will determine individual motor evoked potential (MEP) thresholds
           before beginning the study treatment. MEP will be recorded from a muscle located between
           the right thumb and index finger, and then from the left thumb and index finger. MEP
           threshold refers to the amount of stimulation to the brain that is required to activate
           muscle cells enough to appear on an electromyography (EMG), which records electrical
           potential in muscle through electrodes placed on the skin.

        3. The investigators will use TMS to test motor cortex functions. For these tests,
           participants will sit in a chair that looks like the one at the dentist's office. A
           magnetic coil will be placed on the scalp on one side of the head, overlying the brain's
           motor cortex to stimulate the brain's output to the muscles in the opposite hand. A
           second magnetic coil will be placed on the scalp of opposite side. Recordings from both
           hands will be made using the magnetic coils placed on scalp.

        4. The investigators will collect data about the muscles of both the upper and lower limbs
           with a wireless EMG procedure. To do this, small wireless sensors will be placed on the
           skin over both arm and leg muscles. Participants will be asked to sit in a chair and
           perform movements with the upper and lower limbs while the EMG records measurements
           about movement activity. This procedure will be conducted separately for the upper and
           lower limbs.

        5. Participants who have provided consent will be videotaped during the visits.

        6. Side effects and adverse events pertaining to this study will be recorded at each visit.
    

Intervention name(s): Transcranial Magnetic Stimulation (TMS); Motor Physiology Testing
Intervention type(s): Procedure; Procedure
Intervention description(s): Participants sit in a chair that looks like one in a dentist's office. A magnetic coil will be placed on the scalp on one side of the head, overlying the brain's motor cortex to stimulate the brain's output to the muscles in the opposite hand. A second magnetic coil will be placed on the scalp of the opposite side. Recordings from both hands will be made using the magnetic coils placed on scalp. Results will be compared for participants with and without Parkinson's Disease.; Participants will be asked to move their upper and lower limbs while seated in a chair. Wireless EMG sensors placed on arm and leg muscles will record measurements during this procedure. Upper and lower limb testing will be performed separately.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: parkinson; PD; parkinson disease; parkinson's; parkinson's disease; parkinsons; parkinsons disease; TMS; DBS; transcranial magnetic stimulation; deep brain stimulation