Electrophysiological, neurocognitive, and GFAP biomarker responses to corticosteroid therapy in children with ESES/CSWS.

Abstract

Developmental and/or epileptic encephalopathy with spike-wave activation during sleep (DE SWAS), including electrical status epilepticus during sleep (ESES/CSWS), is associated with seizures, neurocognitive regression, and characteristic electroencephalographic abnormalities. This study aimed to evaluate the clinical, electrophysiological, neurocognitive, and molecular response to corticosteroid therapy in children diagnosed with DE-SWAS, with a particular focus on serum glial fibrillary acidic protein (GFAP) as a potential biomarker of treatment response. Eleven children aged 6-12 years were retrospectively evaluated using clinical records, sleep electroencephalography with quantification of the spike-wave index (SWI), standardized neuropsychological test results, and serum GFAP measurements obtained before and after corticosteroid treatment. Neurocognitive assessment included the Wechsler Intelligence Scale for Children-Revised (WISC-R), Stroop Color and Word Test, Bender Visual-Motor Gestalt Test, and Turkish Receptive and Expressive Language Test (TIFALDI)High-dose intravenous methylprednisolone was administered monthly for six months. During follow-up, four patients became seizure-free, while the remaining seven demonstrated a reduction in seizure frequency and duration exceeding 50%. Complete normalization of electroencephalographic findings was observed in four patients, and a ≥ 50% reduction in SWI was observed in the remaining seven. Post-treatment neurocognitive evaluations demonstrated overall improvement, particularly in attention, executive functions, and receptive language domains. Mean serum GFAP levels decreased significantly following corticosteroid therapy (p = .017). These findings suggest that corticosteroid therapy is associated with favorable clinical, electrophysiological, and neurocognitive outcomes in children with DE-SWAS and that GFAP may represent a promising biomarker of disease activity and therapeutic response. Larger prospective studies are warranted to validate these results.