Electrophysiological patterns and therapeutic outcomes in DEE-SWAS: A cohort study from a tertiary pediatric neurology center.

OBJECTIVE

This study aimed to evaluate the clinical, electrophysiological, and radiological characteristics of pediatric patients diagnosed with developmental and epileptic encephalopathy with spike-wave activation during sleep (DEE-SWAS) and to identify factors associated with prognosis.

METHODS

Twenty-five pediatric patients with a spike-wave index (SWI) ≥50% and a minimum of 2 years of follow-up were analyzed in this retrospective cohort study. Clinical data, electroencephalogram (EEG) findings, and neuroimaging results were assessed, and their relationship with residual neurological or electrophysiological abnormalities was examined.

RESULTS

The patients' mean age was 9.4 ± 2.97 years, with a mean age at seizure onset of 6.6 ± 2.32 years. Etiologically, 60% of patients were unknown, and 40% were known. The baseline mean SWI was 67.1%, decreasing to 13.8% by the 24th month. Patients with residual findings had significantly higher SWI values at months 3, 6, and 24 (p = .04, p = .006, and p = .01, respectively). Additionally, these patients exhibited lower EEG background frequency and higher amplitude during wakefulness (p = .026 and p = .001). Abnormal neurological examination was significantly associated with the presence of residual findings (p = .02).

SIGNIFICANCE: Early and substantial reduction in SWI is associated with better prognosis. Persistent high SWI and abnormal background EEG activity may serve as predictors of long-term neurological impairment. These findings underscored the importance of early identification of high-risk patients and personalized treatment strategies in the management of DEE-SWAS.