EEG microstate alterations in Parkinson's disease dementia

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Parkinson's disease (PD) is a neurodegenerative disorder affecting motor function and often leading to cognitive impairment.
• Resting-state electroencephalogram (EEG) microstates represent fundamental neuronal network states.
• Understanding EEG microstate alterations in PD can elucidate cognitive dysfunction mechanisms.

Purpose of the Study:

• To investigate changes in resting-state EEG microstates across the cognitive spectrum of Parkinson's disease (PD).
• To assess the utility of EEG microstates as electrophysiological biomarkers for cognitive impairment in PD.

Main Methods:

• Resting-state EEG was recorded from 36 healthy controls (HC), 38 PD patients with normal cognition (PDNC), and 39 PD patients with dementia (PDD).
• Temporal parameters (duration, occurrence, coverage) of six canonical microstates (A-F) were analyzed.
• Correlation analyses were performed between microstate metrics and Montreal Cognitive Assessment (MoCA) scores.

Main Results:

• PDD patients showed longer durations of microstates A, C, and E, and lower occurrences of microstates B and C compared to PDNC and HC groups.
• Microstate A and C durations negatively correlated with MoCA scores, indicating worsening cognition with longer durations.
• Microstate B and C occurrences positively correlated with MoCA scores, suggesting preserved cognition with higher occurrences.

Conclusions:

• Specific EEG microstate abnormalities are associated with cognitive status in Parkinson's disease.
• Prolonged microstates A and C, and reduced occurrences of microstates B and C, serve as stage-sensitive biomarkers reflecting cognitive decline severity.
• These findings offer novel insights into the neural mechanisms underlying PD-related cognitive dysfunction.