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

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. Clinical information of children with focal PSW (n = 326) was compared with control patients with focal negative interictal epileptiform discharges (n = 898). 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. Positive spike waves on pediatric EEG are associated with congenital or acquired brain abnormalities and less favorable seizure and neurodevelopmental outcomes.