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Updated: May 31, 2026
Microstate and Omega Complexity Analyses of the Resting-state Electroencephalography
Published on: June 15, 2018
Resting-state EEG markers of cognitive dysfunction in epilepsy: evidence from gamma power, alpha activity, and
Fatima Nasrollahzadeh Masoumian1,2, Sobhan Bamdad1,2, Angelina Laganà1
1Neurophysiopathology and Movement Disorders Clinic, University of Messina, Messina, Italy.
Purpose:
Cognitive dysfunction is a common comorbidity in epilepsy, linked to disrupted neural oscillations and network synchronization. Resting-state electroencephalography (EEG) provides a non-invasive approach to identify electrophysiological biomarkers of cognitive dysfunction. This study examined relationships between resting-state EEG spectral power, functional connectivity, and cognitive performance among people with epilepsy.
Methods:
Sixty-five persons with epilepsy (mean age 38.72 ± 1.63 years) underwent eyes-closed resting-state EEG and Montreal Cognitive Assessment (MoCA). Participants were classified into preserved cognition (nPCCD; MoCA ≥ 26, n = 35) and comorbid cognitive dysfunction (PCCD; MoCA < 26, n = 30) groups. Power spectral density (PSD) and band-powers were extracted from clean EEG, and functional connectivity was assessed via magnitude-squared coherence. Pearson correlations assessed associations between MoCA and band-powers, and group comparisons evaluated inter-group differences.
Results:
Global gamma power negatively correlated with MoCA scores all (r= -0.30, p = 0.01, n = 65) and PCCD group (r= -0.57, p = 0.0003), indicating higher gamma activity with poorer cognition. The nPCCD group exhibited higher global alpha power than the PCCD group [17.48 ± 2.63 vs. 10.83 ± 1.76 µV²/Hz, p = 0.0091], with topographic significance over bilateral temporal and parietal regions (15 channels, p < 0.05). Functional connectivity differed between groups across frequency bands, most prominently in alpha. (p < 0.05).
Conclusions:
Resting-state EEG reveals elevated gamma power significantly correlates with poorer cognitive performance across all participants as well as PCCD, and also reduced alpha power, and altered functional connectivity as neurophysiological markers of cognitive dysfunction in epilepsy. Combining spectral and network-level measures may improve characterization, early identification, and targeted management of cognitive comorbidity in epilepsy.
