EEG microstates modulate TMS-evoked responses in genetic generalized epilepsy

Area of Science:

• Neuroscience
• Epilepsy Research
• Brain-Computer Interfaces

Background:

• Neural state heterogeneity impacts neurostimulation outcomes.
• Understanding these states is crucial for targeted therapies in epilepsy.

Purpose of the Study:

• Investigate microstate-specific effects of transcranial magnetic stimulation (TMS) on electroencephalography (EEG) responses in genetic generalized epilepsy (GGE).
• Analyze TMS-evoked potentials (TEPs) and other characteristics across different EEG microstates in GGE patients.

Main Methods:

• Collected resting-state EEG and TMS-EEG data from 24 GGE patients.
• Classified trials based on four microstates and analyzed TEPs, topography, and natural frequencies.
• Examined correlations between TEP components and clinical features.

Main Results:

• Significant differences in the P180 component amplitude were observed across microstates A, C, and D.
• Microstates A and D showed altered N100 and P180 amplitudes compared to random stimulation; microstate C showed higher P180.
• No differences in TMS-induced natural frequencies or correlations with clinical variables were found.

Conclusions:

• Microstate-specific TMS-EEG signatures in GGE may reduce variability and enhance patient stratification.
• Further validation in larger cohorts is needed to confirm clinical relevance and robustness.