Increased large-scale inter-network connectivity in relation to impulsivity in Parkinson's disease

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Impulsivity is a common neuropsychiatric symptom in Parkinson's disease (PD).
• Understanding the neural basis of impulsivity in PD is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the pathophysiology of impulsivity in Parkinson's disease using resting-state functional magnetic resonance imaging (rs-fMRI).
• To explore the relationship between functional connectivity (FC) of large-scale brain networks and different facets of impulsivity in PD patients.

Main Methods:

• rs-fMRI data were acquired from 45 idiopathic PD patients and 21 healthy controls.
• PD patients were categorized into higher impulsivity (PD-HI) and lower impulsivity (PD-LI) groups based on the Barratt Impulsiveness Scale (BIS-11).
• Functional connectivity (FC) between brain networks was analyzed using the CONN toolbox, with statistical significance determined by false discovery rate (FDR) correction.

Main Results:

• PD-HI patients exhibited significantly higher FC between the right frontoparietal network (FPN) and the medial visual network (MVN) compared to PD-LI patients (FDR-adjusted p = 0.0315).
• FC between the right FPN and MVN positively correlated with total BIS-11 scores, attentional impulsivity, and non-planning impulsivity scores.
• Motor impulsivity showed a negative correlation with FC between the default-mode and salience networks in both PD patients and controls.

Conclusions:

• Cognitive impulsivity (attentional and non-planning) in PD may stem from impaired integration of perceptual information and cognitive control.
• Altered functional connectivity, particularly involving the FPN and MVN, is implicated in the impulsivity observed in Parkinson's disease.
• These findings highlight specific neural network dysfunctions associated with different types of impulsivity in PD, offering potential targets for future research and treatment.