Altered EEG Microstate Dynamics in First Unprovoked Seizure and Newly Diagnosed Epilepsy Patients

Abstract

Objective: To identify the Electroencephalogram (EEG) microstate characteristics that can distinguish between patients with first unprovoked seizure (FUS) and newly diagnosed epilepsy (NDE), providing insight into predicting the progress of FUS to NDE, and to find the predictive biomarkers for the responsiveness to initial antiseizure medication (ASM) therapy.

Methods: Fifty-six NDE patients in a drug naïve state, 26 FUS patients, and 31 healthy controls (HCs) were compared on microstates features of 21-channel resting-state EEG without artifact. Four classic EEG microstates (A, B, C and D) were derived. The global explained variance (GEV), mean duration (MD), time coverage (TC), and frequency of occurrence (FO) of each microstate were calculated.

Results: NDE and FUS patients exhibited decreased MD, TC, and FO in microstate C compared to the HCs. The FUS patients showed decreased MD, TC, and FO in microstate A compared to the NDE patients. Non-seizure free (NSF) patients showed longer MD, higher TC, and FO in microstate B compared to the seizure free (SF) patients.

Significance: EEG microstate serves as electrophysiological markers that can distinguish between patients with FUS and NDE. Additionally, EEG microstate parameters can also serve as the predictive biomarkers for the responsiveness to initial ASM therapy.

Keywords: EEG microstate; drug responsiveness; first unprovoked seizure; newly diagnosed epilepsy.