Neuroimaging and neurophysiology in infantile‐onset epilepsy after neonatal stroke

AIM: To identify neuroimaging and neurophysiological markers predictive of infantile-onset and childhood-onset epilepsy after neonatal stroke. METHOD: This retrospective observational study included a population-based cohort of 55 consecutive newborn infants (born between 34 + 4 and 42 + 2 gestational weeks; 23 females) with neonatal stroke, who were followed up (median = 80 months, range = 33-139 months) for the epilepsy outcomes at ages 1 year (infantile-onset) and 4 years (childhood-onset). Outcome prediction was assessed in relation to neonatal magnetic resonance imaging, neonatal somatosensory evoked potentials, and electroencephalogram (EEG) findings from both the neonatal period and infancy. RESULTS: When compared to 1-year-olds without epilepsy, children with infantile-onset epilepsy (n = 6) had infarction of the proximal middle cerebral artery, asymmetry in neonatal EEG, and unilaterally or bilaterally absent somatosensory evoked potentials significantly more often. They also had higher total and maximal hourly seizure burden during the neonatal period and recurrent epileptiform activity already in their first follow-up EEG. In contrast, childhood-onset epilepsy (n = 3) was significantly linked only to asymmetry in neonatal EEG, compared with children without epilepsy at 4 years of age. INTERPRETATION: Neonatal neuroimaging and neurophysiology, combined with follow-up EEGs, enabled the identification of children at the highest risk for infantile-onset epilepsy after neonatal stroke.