EEG microstates during resting-state and dissociative events in patients with psychogenic non-epileptic seizures.
Cecilia Catania, Marco Mancuso, Adolfo Mazzeo, Enrico Michele Salamone, Biagio Orlando, Alessandra Morano, Giorgio Leodori, Sara Casciato, Giancarlo Di Gennaro, Anna Teresa Giallonardo, Carlo Di Bonaventura, Emanuele Cerulli Irelli
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology May 1, 2025 DOI: 10.1016/j.clinph.2025.03.002 via PubMed
Summary
AI-generated from the abstractIn people with psychogenic non-epileptic seizures (PNES), a type of dissociative event, brain activity patterns shift markedly during the events compared to resting periods. EEG microstate analysis of 22 PNES patients and 24 healthy controls showed that microstate C, linked to the default mode network, was more prominent at rest in patients than in controls, but its duration, coverage, and global field power all decreased significantly during PNES events. This suggests a major change in default mode network dynamics during dissociative events, pointing to a mix of pathological and adaptive brain processes underlying PNES.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 46 |
| Population | 22 PNES patients and 24 age- and sex-matched healthy controls |
| Keywords | Dissociative Functional neurological disorders Pathophysiology Resting state |
| Citations | 3 |
| Key finding | Microstate C, associated with the default mode network, showed increased duration at rest in PNES patients versus controls but decreased representation during PNES events, indicating a shift in neural activity dynamics during dissociative events. |
Abstract
Previous neuroimaging studies indicate complex network alterations in psychogenic non-epileptic seizures (PNES) patients, but brain activity modifications occurring during PNES remain unexplored. This study aimed to analyze EEG microstate metrics in PNES patients both during events and resting state to investigate the neurophysiological changes underlying these dissociative events. We recruited 22 PNES patients and 24 age- and sex-matched healthy controls. Inclusion criteria included a history of PNES and at least one recorded akinetic PNES during video-EEG. A two-way repeated-measures ANOVA revealed significant class*condition interactions for microstate duration (p = 0.017), coverage (p = 0.012), and global field power (GFP) (p = 0.008). Post-hoc FDR-adjusted paired t-tests showed a significant decrease in microstate C duration (p = 0.036), coverage (p = 0.04), and GFP (p = 0.036) during PNES events compared to resting state. Mann-Whitney U tests showed significantly higher microstate C duration in PNES patients during resting state compared to controls (p = 0.009). Microstate C, previously associated with the default mode network, showed increased duration during resting state and decreased representation during PNES, suggesting a prominent shift in neural activity dynamics within this network during dissociative events. These findings provide insights into neurophysiological changes occurring during PNES, suggestingan interplay between pathological and adaptive mechanisms in their pathophysiology.