# Biomarkers of Impulsivity in Parkinson's Disease

> **NIH VA I01** · MINNEAPOLIS VA  MEDICAL CENTER · 2024 · —

## Abstract

In recent years, excessive impulsivity and impulse control disorders (ICDs), which commonly include
pathological gambling, compulsive shopping, binge-eating, and hypersexuality, have been recognized as an
important complication of Parkinson's disease (PD). Both impulsivity and ICDs negatively affect patients and
their family quality of life and emotional well-being. In addition, ICDs are a cause of considerable increase in
care burden. For these reasons, the problem of excessive impulsivity has become a crucial issue in regards to
the care of PD patients. Dopamine-replacement therapy (DRT), in particular dopamine agonists and to a
lesser extend l-dopa, have been recognized as a major factor in the increase in impulsivity in PD patients.
Accordingly, the main treatment response currently is the decrease or removal of dopamine agonist
medications, which however entails the risk of development of dopamine agonist withdrawal syndrome and of
recurrence of more severe motor symptoms. However, when excessive impulsivity results from l-dopa alone
not much can be done currently to control both motor symptoms and impulsivity. For these reasons, more
research is critically needed to better understand the pathophysiology of impulsivity in PD, and to develop
more effective care.
Impulsivity in PD patients has been found to be composed of two main dimensions identified as motor
impulsivity and decision-making impulsivity. This distinction suggests that different neural networks may be
affected across PD patients. Accordingly, the limited effectiveness of current treatments of PD-related ICDs
may be due to divergent pathophysiological mechanisms, as well as to the scarce understanding of how
impulsivity modulates the brain networks associated with decision-making and response planning. Some
studies have investigated the neural mechanisms of motor impulsivity in PD patients, and a few have
investigated those of decision-making impulsivity. However, to our knowledge no study has ever been designed
to investigate specifically how DRT affects the electrophysiological activity within the neural networks
associated with the two main dimensions of impulsivity and how this information can prospectively improve
patient care. With this project, we intend to begin to fill this gap.
We plan to identify the neural signatures of impulsivity in controls and Parkinson's patients using
magnetoencephalography (MEG), which provides high temporal resolution of oscillatory activity over the
whole brain. Subjects will complete questionnaires relative to impulsivity and ICDs, and then perform two
tasks –go/no-go task and Iowa gambling task– assessing the two main dimensions of impulsivity (i.e., motor
impulsivity and decision-making impulsivity, respectively) during MEG recording. Patients will be studied
both on and off their DRT to determine its effect on the networks associated with each dimension of
impulsivity. In addition, these data will be used to create neurophysiological mo...

## Key facts

- **NIH application ID:** 11116831
- **Project number:** 5I01CX001773-06
- **Recipient organization:** MINNEAPOLIS VA  MEDICAL CENTER
- **Principal Investigator:** SCOTT M LEWIS
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2019-07-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11116831

## Citation

> US National Institutes of Health, RePORTER application 11116831, Biomarkers of Impulsivity in Parkinson's Disease (5I01CX001773-06). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/11116831. Licensed CC0.

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