Temporal dynamics of electroencephalographic microstates during sustained pain

Abstract

Brain dynamics can be modeled by a sequence of transient, nonoverlapping patterns of quasi-stable electrical potentials named “microstates.” While electroencephalographic (EEG) microstates among patients with chronic pain remained inconsistent in the literature, this study characterizes the temporal dynamics of EEG microstates among healthy individuals during experimental sustained pain. We applied capsaicin (pain condition) or control (no-pain condition) cream to 58 healthy participants in different sessions and recorded resting-state EEG 15 min after application. We identified 4 canonical microstates (A–D) that are related to auditory, visual, salience, and attentional networks. Microstate C had less occurrence, as were bidirectional transitions between microstate C and microstates A and B during sustained pain. In contrast, sustained pain was associated with more frequent and longer duration of microsite D, as well as more bidirectional transitions between microstate D and microstates A and B. Microstate D duration positively correlated with intensity of ongoing pain. Sustained pain improved global integration within microstate C functional network, but weakened global integration and efficiency within microstate D functional network. These results suggest that sustained pain leads to an imbalance between processes that load on saliency (microstate C) and processes related to switching and reorientation of attention (microstate D).

Preoperative resting‐state microstate as a marker for chronic pain after breast cancer surgery

“…As mentioned previously, the attention network is generally considered to be associated with MS-D from a microstate perspective. Recent research has discovered a significant correlation between the duration and coverage of MS-D and pain intensity during sustained pain induced by capsaicin (Qiu et al, 2023). Another study (May et al, 2021) also found fewer occurrences of MS-D in patients with chronic pain.…”