Neural Correlates of Cognition in Parkinson’s Disease


Cognitive impairment in Parkinson's disease (PD) has far-reaching effects on both motor outcomes and quality of life in PD patients. Furthermore, deep brain stimulation (DBS), now an evidence-based treatment for certain cases of PD, has the risk of causing deficits in multiple areas of cognition. As such, the purpose of this study is to understand the neuroanatomical and neurophysiologic basis for impaired cognition in PD. The aim is to identify neural correlates of cognition by measuring brain signal activity while PD patients are engaged in cognition on a computer.

Full Title of Study: “Neural Correlates of Cognition in Parkinson’s Disease”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Non-Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Basic Science
    • Masking: None (Open Label)
  • Study Primary Completion Date: October 25, 2020

Detailed Description

Study Participants: For this study, the investigators will recruit 75 Parkinson's disease (PD) patients that are undergoing deep brain stimulation (DBS) as routine standard of care. Screening: For healthy control participants, investigators will approach adults, aged 18-90, for possible involvement in our study. Potential participants will be asked if they have ever been diagnosed with a movement disorder, psychiatric disorder, or dementia. For PD patients undergoing evaluation for DBS, investigators will first consult with their neurologist and neurosurgeon. Next, investigators will approach the participant and explain the study. PD Participants: As part of the usual DBS process at University of Florida (UF), PD participants will be asked to participate in this trial. There are three evaluation time points: before surgery, during surgery, and possibly after surgery. Before surgery, the PD patients will complete standardized questionnaires and be trained on a computer game to assess cognition. During surgery, the participants will play the same computer game while brain signals are recorded. When the patients return to University of Florida for DBS programming visits within 48 months after surgery, they will repeat the standardized questionnaires and computer game once again.


  • Behavioral: Computer task assessing cognition
    • Participants will complete a short computer game to assess cognition.
  • Behavioral: Impulsive-Compulsive Disorders in Parkinson’s Disease
    • Standard clinical questionnaire
  • Procedure: Deep Brain Stimulation Surgery
    • DBS surgery for the implantation of electrodes for the treatment of motor disorders.

Arms, Groups and Cohorts

  • Active Comparator: Control group
    • Healthy adults ages 18-90 without movement disorders, psychiatric disorders, or dementia. They will complete computer games and questionnaires at one time point. Specific interventions: Computer task assessing cognition, Impulsive-Compulsive Disorders in Parkinson’s Disease, Montreal Cognitive Assessment
  • Active Comparator: Parkinson’s disease group with DBS
    • Parkinson’s disease patients who have elected to receive DBS for treatment of their side effects of PD consent to complete computer games and questionnaires at baseline, computer games during deep brain stimulation, and computer games and questionnaires up to 2 years after surgery. Specific interventions: Computer task assessing cognition, Impulsive-Compulsive Disorders in Parkinson’s Disease, Montreal Cognitive Assessment

Clinical Trial Outcome Measures

Primary Measures

  • Change in behavioral performance
    • Time Frame: Baseline, before surgery, during surgery, and up to 2 years after surgery
    • Behavioral performance will be assessed by the computer game that assess cognition. All computer games used in this study will have a similar form. The computer will record responses to each trial during the computer game.

Secondary Measures

  • Change in Score on Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease – Rating Scale (QUIP-RS)
    • Time Frame: Baseline, before surgery, during surgery, and up to 2 years after surgery
    • Assess the scores from a standard clinical questionnaire called QUIP-RS. Scores range from 0 to 112.
  • Local field potential brain signal
    • Time Frame: At time of surgery
    • Measuring Brain signal while Parkinson’s disease patients play a computer game during surgery. Local field potential is measured in Hertz (Hz)

Participating in This Clinical Trial

PD-DBS Participants: Inclusion Criteria:

Persons undergoing DBS surgery for the implantation of electrodes for the treatment of motor disorders Exclusion Criteria:

Failure of the DBS surgical candidacy screening process Non-DBS PD Participants: Inclusion Criteria:

Persons diagnosed with idiopathic Parkinson's disease and have not received and are not currently scheduled for DBS. Exclusion Criteria:

Individuals that :

  • that have been diagnosed with dementia or other serious brain diseases or disorders such as strokes, traumatic brain injury, or brain tumor (the exception is Parkinson's disease) – who have had drug or alcohol abuse within the past 12 months – with severe sensory difficulties such as impaired vision or hearing – currently experiencing significant depression or sadness – with a history of schizophrenia or other serious mental health problems – using cognitive medications (e.g., Aricept) or stimulants (e.g., Adderall) – who have undergone deep brain stimulation, fetal cell implants, or other brain surgeries

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • University of Florida
  • Collaborator
    • National Institute of Neurological Disorders and Stroke (NINDS)
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Aysegul Gunduz, PhD, Principal Investigator, University of Florida


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