Alpha-ERSP as a prognostic biomarker in infantile epileptic spasms syndrome: Insights from quantitative EEG analysis.

Objective: This study aimed to identify a reliable EEG biomarker for predicting key prognosis in patients with infantile epileptic spasms syndrome (IESS), using modulation index (MI) and event-related spectral perturbation (ERSP) from pre-treatment diagnostic EEGs.

Method: This observational study included 45 infants diagnosed with IESS at Asan Medical Center Children's Hospital, Korea, between May 2009 and December 2020. Outcomes were evaluated as three separate binary measures: (1) Electro-clinical spasm freedom, (2) Manageable versus intractable epilepsy, and (3) Good versus poor neurodevelopmental outcome.

Result: Clinical factors associated with favorable outcomes included unknown etiology, no prior seizure history, and fewer treatment burdens. Quantitative EEG analysis revealed significantly higher Alpha-ERSP values in patients with spasm freedom, manageable epilepsy, and good neurodevelopmental outcomes compared to their counterparts. Alpha-ERSP with cut-off values of 4.343 predicted spasm freedom with an area under the curve (AUC) of 0.946, manageable epilepsy with an AUC of 0.754, and good neurodevelopmental outcomes with an AUC of 0.774.

Conclusion: Quantitative EEG analysis revealed significantly higher Alpha-ERSP values in patients with favorable outcomes, including spasm freedom, manageable epilepsy, and good neurodevelopmental progress. Alpha-ERSP from pre-treatment EEG emerges as a robust predictor of electro-clinical spasm freedom, intractable epilepsy, and neurodevelopmental outcomes in IESS.