Childhood-onset epilepsy: Longitudinal seizure outcomes in a large single-center cohort

Epilepsy is the most common serious neurological disorder in children; however, previous long-term studies are often limited by small sample sizes or methodological variability. This study aimed to assess the epidemiology, seizure outcomes, and prognostic factors of childhood-onset epilepsy over > 10 years of follow-up at a single tertiary center.

We retrospectively analyzed the medical records of 4248 patients diagnosed with epilepsy before age 19 between 1995 and 2017 at Asan Medical Center Children's Hospital. All patients underwent at least one electroencephalogram (EEG) and received anti-seizure medications (ASMs) for > 2 years.

During a mean follow-up of 11.0 years, 43 patients (1.0 %) died. The median age at seizure onset was 7.2 years. Etiologies included unknown (52.5 %), structural (29.3 %), genetic/metabolic (23.4 %), and infectious/autoimmune (4.5 %). Focal epilepsy was the most common (63.4 %). Neurocognitive and psychological comorbidities were observed in 32.7 % and 20.6 % of patients, respectively. Seizure freedom for ≥ 2 years was achieved in 81.2 %, and terminal remission in 63.1 %. However, relapse occurred in 38.0 %, and 28.6 % developed intractable epilepsy. Prognostic factors included status epilepticus, intellectual disability, pretreatment seizure frequency, etiology, epilepsy syndromes, and EEG abnormalities.

This study reaffirms known risk factors while providing comprehensive insights into seizure trajectories, relapse patterns, and treatment responses in a large cohort. It highlights the clinical relevance of the 2-year seizure-free definition and underscores the need for early interventions in high-risk subgroups. Despite diagnostic advances, several cases remain etiologically unresolved, reinforcing the importance of expanding access to molecular and imaging tools in pediatric epilepsy care.