Investigating Inhibitory Control Networks in Parkinson's Disease

OTHER

Procedure/Surgery: Response Inhibition and Deep Brain Stimulation in Parkinson's disease

After creation of the burr hole and prior to DBS electrode placement, 1-2 subdural strip electrodes will be placed anteriorly or posteriorly from the cranial opening. These electrodes are routinely placed using this technique for seizure mapping, with arrays of electrodes (up to 6) being placed around the perimeter of the opening.14 Subdural strips vary in length and contact size (e.g., the 6-contact Ad-Tech strip), and are currently placed predominantly for studies of sensorimotor function,13 including at our institution (IRB-140327003). Placement over prefrontal areas is performed at other institutions.11-13 The DBS surgery will then proceed according to routine practice, and following lead placement in the optimal desired location, the research task paradigm will begin.

Accuracy via Simon Task (% correct)

Time frame: Baseline

In the Simon task, participants are instructed to respond with a right or left button press (Right = Red, Left = Blue) according to how a word is printed on a screen ("RED" or "BLUE"), regardless of the color in which the word is printed. This is a measurement of accuracy (% correct, ranging from 0-100, with higher scores indicating better performance)

Response times via Simon Task (sec)

Time frame: Baseline

In the Simon task, participants are instructed to respond with a right or left button press according to the word "RIGHT" or "LEFT" that appears on a screen, regardless of where on the screen it actually appears. This is a measurement response times (continuous measure, from 0-4000 milliseconds) between correct and incorrect responses.

Simon Effect on Response times (sec)

Time frame: Baseline

Participants will perform the Simon task as described, and the Simon effect will be calculated as the difference in response times between congruent and incongruent trials

Simon Effect on Accuracy (% correct)

Time frame: Baseline

Participants will perform the Simon task as described, and the Simon effect will be calculated as the difference in accuracy between congruent and incongruent trials

United Parkinson's disease Rating Scale part 3: Motor Examination Score 0-108 (Higher score represents worse symptoms)

Time frame: Baseline

Participants will undergo motor evaluation using the validated United Parkinson's disease Rating Scale (UPDRS) part 3.

Dementia Rating Scale Score 0-144 points (Higher score represents better symptoms)

Time frame: Baseline

Participants will undergo neuropsychological testing as part of routine care, including the Dementia Rating Scale

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.