Predictive modeling based on functional connectivity of interictal scalp EEG for infantile epileptic spasms syndrome

•We conducted quantitative EEG analyses to explore outcome group differences in infantile epileptic spasms syndrome (IESS).•The “hyper-synchronous state,” which ameliorated after treatment in the seizure-free group, indicates deep brain dysfunction.•We developed a model predicting long-term seizure outcomes from EEG functional connectivity at the onset of IESS. This study aims to delineate the electrophysiological variances between patients with infantile epileptic spasms syndrome (IESS) and healthy controls and to devise a predictive model for long-term seizure outcomes. The cohort consisted of 30 individuals in the seizure-free group, 23 in the seizure-residual group, and 20 in the control group. We conducted a comprehensive analysis of pretreatment electroencephalography, including the relative power spectrum (rPS), weighted phase-lag index (wPLI), and network metrics. Follow-up EEGs at 2 years of age were also analyzed to elucidate physiological changes among groups. Infants in the seizure-residual group exhibited increased rPS in theta and alpha bands at IESS onset compared to the other groups (all p