Impulsivity in Parkinson's Disease Is Associated With Alterations in Affective and Sensorimotor Striatal Networks.

Marit F L Ruitenberg,Tina Wu,Kelvin L Chou,Vincent Koppelmans,Rachael D Seidler,Bruno B Averbeck

doi:10.3389/fneur.2018.00279

Abstract

A subset of patients with Parkinson’s disease (PD) experiences problems with impulse control, characterized by a loss of voluntary control over impulses, drives, or temptations regarding excessive hedonic behavior. The present study aimed to better understand the neural basis of such impulse control disorders (ICDs) in PD. We collected resting-state functional connectivity and structural MRI data from 21 PD patients with ICDs and 30 patients without such disorders. To assess impulsivity, all patients completed the Barratt Impulsiveness Scale and performed an information-gathering task. MRI results demonstrated substantial differences in neural characteristics between PD patients with and without ICDs. Results showed that impulsivity was linked to alterations in affective basal ganglia circuitries. Specifically, reduced frontal–striatal connectivity and GPe volume were associated with more impulsivity. We suggest that these changes affect decision making and result in a preference for risky or inappropriate actions. Results further showed that impulsivity was linked to alterations in sensorimotor striatal networks. Enhanced connectivity within this network and larger putamen volume were associated with more impulsivity. We propose that these changes affect sensorimotor processing such that patients have a greater propensity to act. Our findings suggest that the two mechanisms jointly contribute to impulsive behaviors in PD.

Highlights

6–15.5% of Parkinson’s disease (PD) patients experience problems with impulse control [1,2,3]
Results revealed an increased connectivity between the left STN and the left parietal operculum in the impulse control disorders (ICDs)+ group that was significant at an family-wise error (FWE)-corrected threshold
When evaluating results at the uncorrected threshold, we further observed that patients in the ICD+ group showed a reduced gray matter (GM) volume in the right GPe compared to patients in the ICD− group

Summary

Introduction

6–15.5% of Parkinson’s disease (PD) patients experience problems with impulse control [1,2,3]. Impulse control disorders (ICDs) are characterized by a loss of voluntary control over impulses, drives, or temptations to engage in excessive hedonic behavior that interferes with daily functioning and is harmful to the patient and/or others. The most common ICDs in PD are pathological gambling, hypersexual behavior, compulsive buying, and compulsive eating [e.g., Ref. There are indications that dopamine agonists are linked to ICDs in PD [e.g., Ref. PD patients with ICDs compared to those without have a reduced reward circuitry functional connectivity between the striatum and anterior cingulate cortex (ACC) [8, 9].

Methods

Results

Conclusion