Clinical Significance of Positive Spike Wave Discharges in the Pediatric Population: Insights Beyond Neonates.

Introduction: Positive spike wave (PSW) discharges on EEG are well-documented in neonates, but data regarding their significance in other populations are limited. This study aimed to assess the clinical significance of PSW in children aged 1 month to 19 years at a single tertiary care center over approximately three decades.

Methods: Clinical information of children with focal PSW (n = 326) was compared with control patients with focal negative interictal epileptiform discharges (n = 898).

Results: From 77,500 pediatric EEGs in our laboratory from 1992 to 2020, PSW were identified in 445 (0.57%) children, of which 326 met inclusion criteria. Positive spike waves were located in the following brain regions: occipital (139), central (65), frontal (63), temporal (43), parietal (9), and centro-temporal (7). Positive spike wave patients had a younger median age of seizure onset than control patients (1.1 years [0.30, 4.00] versus 4 years [1.3, 7.5], P < 0.001).Logistic regression analysis confirmed that PSW were associated with high odds of seizures [odds ratios (OR) 3.78; CI: 2.14-2.14; P < 0.005], epilepsy [OR 2.05; CI: 1.39-1.39; P < 0.005], and drug-resistant epilepsy, [OR 3.51; CI: 2.67-2.67; P < 0.005]. Furthermore, PSW correlated with a greater odd of developmental delay [OR 3.69; CI: 2.77-2.77; P < 0.005], school difficulties [OR 2.85; CI: 2.07-2.07; P < 0.005], abnormal neurologic exam [OR 2.8; CI: 2.15-2.15; P < <0.005], and structural brain abnormalities [OR 1.74; CI: 1.32-1.32; P < 0.005], such as malformation of cortical development, compared with control patients.

Conclusions: Positive spike waves on pediatric EEG are associated with congenital or acquired brain abnormalities and less favorable seizure and neurodevelopmental outcomes.