Dual Frequency Stimulation in Parkinson's Disease

DEVICE

Deep brain stimulation

Patients with idiopathic Parkinson's disease who have previously been implanted with the Boston Scientific VerciseTM DBS system for at least 3 months. These patients will already be receiving high-frequency dorsal STN stimulation as part of the standard of care for PD. Once patients have provided consent and are enrolled in this study, they will receive simultaneous low-frequency stimulation of the ventral STN to examine if there are any effects on cognitive performance.

Mean Change from Baseline in Depression Scores on the Center for Epidemiologic Studies Depression Scale (CES-D)

Time frame: Baseline, Week 2, Week 6, Month 3, and Month 6

The score of the CES-D will be compared across sessions and a score that rises above 20 (out of 60) will be considered positive for the development of depression.

Mean Change from Baseline in Impulsiveness Scores on the Barratt Impulsiveness Scale (BIS-11)

Time frame: Baseline, Week 2, Week 6, Month 3, and Month 6

The score of the BIS-11 will be evaluated across sessions and elevated scores indicate greater impulsivity and risk-taking behavior. The scale involves 30 questions with values from 1-4. Overall scores range from 30-120.

Mean Change from Baseline in Neuropsychiatric Inventory (NPI)

Time frame: Baseline, Week 2, Week 6, Month 3, and Month 6

The NPI assesses frequency, change in severity, and distress over 12 neuropsychiatric domains as evaluated by the caregiver. We will look for a significant score reduction in any domain of the NPI.

Mean Change from Baseline in Movement Scores on Part III of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS)

Time frame: Baseline, Week 2, Week 6, Month 3, and Month 6

Part III of the MDS-UPDRS consists of 18 areas of motor assessments to assess severity of symptoms. Each score is rated in terms of severity from 0-4, with higher scores indicating higher severity of symptoms. A composite score will be evaluated for changes from baseline.

Mean Change from Baseline in Cognitive Performance Scores on the Montreal Cognitive Assessment - Blind (MoCA)

Time frame: Baseline, Hour 24, Week 1, Month 1, Month 2, Month 4, and Month 5

This will be collected via telephone calls. The MoCA-Blind has been validated for telephone administration. We will re-evaluate MoCA-Blind scores during telephone monitoring to assess any changes to cognitive ability. A total score of less than 15 out of a possible 22 indicates greater than mild cognitive impairment.

Mean Change from Baseline in Depression Scores on the CES-D Short Version (CES-D-R10)

Time frame: Baseline, Hour 24, Week 1, Month 1, Month 2, Month 4, and Month 5

This will be collected via telephone calls. Patients will be given an unmarked form with questions and will be able to follow along the telephone conversation and answer each question (0-4 severity rating scale) for 10 questions focused on patient affect. A total score greater than 10 (out of 30) indicates the development of depression symptoms.

Mean Change from Baseline in Motor and Non-Motor Aspects of Daily Living Scores on Parts I and II of the MDS-UPDRS

Time frame: Baseline, Hour 24, Week 1, Month 1, Month 2, Month 4, and Month 5

This will be collected via telephone calls. Patients will be asked questions relating to motor and non-motor aspects of daily living and to rate the severity of their symptoms on a scale from 0-4, with higher scores indicating higher severity of symptoms. We will assess for changes in the composite score from baseline.

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.