Postoperative epileptiform discharges predict seizure outcomes in pediatric low-grade developmental and epilepsy associated tumors.

OBJECTIVE

To assess the prognostic value of interictal epileptiform discharges (iEDs) on postoperative video-EEG in children and adolescents undergoing epilepsy surgery for low-grade developmental and epilepsy-associated tumors (LEATs).

METHODS

This retrospective single-center study analyzed prospectively collected pre- and postoperative EEG data from pediatric LEAT patients. Associations between iED characteristics and seizure outcomes ≥ 24 months after surgery were examined.

RESULTS

Fifty-nine patients with a median postoperative follow-up of 59.0 months (IQR: 36.0-118.0) were included. Univariate analysis identified the presence of a secondary iED focus at 3 months (p = 0.04), persistent iEDs at 12 months (p = 0.007), and a ≥ 50 % increase in iED frequency over time (p = 0.009) as predictors of unfavorable seizure outcomes. Multivariate analysis confirmed that a ≥ 50 % increase in iED frequency within the first 12 months post-surgery was independently associated with unfavorable outcomes (OR: 16.2, 95 % CI: 1.2-555.0, p = 0.037).

CONCLUSIONS

Postoperative iEDs, particularly their evolution over time, are valuable predictors of long-term seizure outcomes following LEAT surgery.

SIGNIFICANCE: Prognostic models for seizure outcomes in LEAT patients should not only include clinical, radiological and surgical characteristics, but also presence and progression of iEDs in postoperative EEGs.