Dynamic functional connectivity changes in Parkinson's disease patients with REM sleep behavior disorder

Area of Science:

• Neuroscience
• Neurology
• Sleep Medicine

Background:

• Rapid eye movement (REM) sleep behavior disorder (RBD) is a common non-motor symptom in Parkinson's disease (PD).
• RBD is characterized by the loss of muscle atonia during REM sleep.
• Understanding the neural underpinnings of RBD in PD is crucial for disease management.

Purpose of the Study:

• To investigate dynamic functional network connectivity alterations in Parkinson's disease patients with probable RBD (PD-pRBD).
• To compare brain network patterns between PD patients with and without probable RBD (PD-npRBD) and healthy controls.

Main Methods:

• Utilized the RBD screening questionnaire (RBDSQ) to classify 126 PD patients.
• Applied independent component analysis, a sliding window approach, and k-means clustering to analyze functional connectivity.
• Examined dynamic changes in brain network states.

Main Results:

• PD-pRBD patients exhibited weaker positive couplings between the visual network (VIS) and default mode network (DMN), DMN and basal ganglia (BG), and within the DMN (State IV) compared to PD-npRBD.
• Both PD-pRBD and PD-npRBD groups showed reduced dwell time and fewer occurrences in a state (State III) characterized by specific positive network correlations, relative to healthy controls.
• Identified distinct dynamic network connectivity patterns associated with RBD in PD.

Conclusions:

• Weaker positive functional couplings within and between the VIS, DMN, and BG networks in State IV may contribute to the pathophysiology of probable RBD in Parkinson's disease.
• Dynamic network alterations provide insights into the neurobiological mechanisms underlying non-motor symptoms in PD.
• These findings highlight the importance of assessing RBD in PD patients and suggest potential therapeutic targets.