Neonatal seizures triple the risk of a remote seizure after perinatal ischemic stroke

Abstract

Objectives:To determine incidence rates and risk factors of remote seizure after perinatal arterial ischemic stroke.Methods:We retrospectively identified a population-based cohort of children with perinatal arterial ischemic stroke (presenting acutely or in a delayed fashion) from a large Northern Californian integrated health care system. We determined incidence and predictors of a remote seizure (unprovoked seizure after neonatal period, defined as 28 days of life) by survival analyses, and measured epilepsy severity in those with active epilepsy (≥1 remote seizure and maintenance anticonvulsant treatment) at last follow-up.Results:Among 87 children with perinatal stroke, 40 (46%) had a seizure in the neonatal period. During a median follow-up of 7.1 years (interquartile range 3.2–10.5), 37 children had ≥1 remote seizure. Remote seizure risk was highest during the first year of life, with a 20% (95% confidence interval [CI] 13%–30%) cumulative incidence by 1 year of age, 46% (CI 35%–58%) by 5 years, and 54% (CI 41%–67%) by 10 years. Neonatal seizures increased the risk of a remote seizure (hazard ratio 2.8, CI 1.3–5.8). Children with neonatal seizures had a 69% (CI 48%–87%) cumulative incidence of remote seizure by age 10 years. Among the 24 children with active epilepsy at last follow-up, 8 (33%) were having monthly seizures despite an anticonvulsant and 7 (29%) were on more than one anticonvulsant.Conclusions:Remote seizures and epilepsy, including medically refractory epilepsy, are common after perinatal stroke. Neonatal seizures are associated with nearly 3-fold increased remote seizure risk.