Temporal dynamics of electroencephalographic microstates during sustained pain

Area of Science:

• Neuroscience
• Cognitive Science
• Pain Research

Background:

• Brain dynamics are modeled by electroencephalographic (EEG) microstates, transient patterns of electrical potentials.
• Previous research on EEG microstates in chronic pain has yielded inconsistent findings.
• Understanding microstate dynamics in healthy individuals experiencing acute pain provides a baseline for clinical studies.

Purpose of the Study:

• To characterize the temporal dynamics of EEG microstates in healthy individuals during experimentally induced sustained pain.
• To investigate how sustained pain influences the occurrence, duration, and transitions of specific microstates.
• To examine the impact of sustained pain on global integration and efficiency within microstate-related functional networks.

Main Methods:

• 58 healthy participants underwent experimental pain induction using capsaicin cream versus a control condition.
• Resting-state EEG was recorded 15 minutes after cream application in both conditions.
• Four canonical microstates (A-D), associated with auditory, visual, salience, and attentional networks, were identified and analyzed.

Main Results:

• Sustained pain reduced the occurrence and transitions of microstate C (salience) but increased the frequency and duration of microstate D (attention).
• Microstate D's duration showed a positive correlation with perceived pain intensity.
• Sustained pain enhanced global integration in the microstate C network but impaired global integration and efficiency in the microstate D network.

Conclusions:

• Sustained pain induces an imbalance between salience processing (microstate C) and attentional switching/reorientation (microstate D).
• The findings highlight altered brain network dynamics under experimental pain, specifically impacting attention and saliency.
• These results provide a foundational understanding of pain-related neural dynamics in healthy individuals.