Determining Risk Factors for Epilepsy After Symptomatic Neonatal Seizures
Patients with an epilepsy diagnosis were more likely to be born preterm, have a brain injury, and to be discharged from the hospital on an anti-seizure medication.
In children with seizures with symptomatic causes in the neonatal period, epilepsy frequency tends to be relatively low and age of onset appears to be around age 5, according to a study published in Pediatric Neurology.
Children with neonatal onset seizures attending the Neonatal Neurocritical Care Service at the University of California San Francisco Benioff Children's Hospital were identified in a large patient database (n=144). Investigators assessed patient demographics, seizure etiology, magnetic resonance imaging (MRI) results, continuous video electroencephalogram (EEG) results, and anti-seizure medication use. Seizure etiology and seizure burden were determined by a neonatal neurologist and a board-certified clinical neurophysiologist, respectively.
The primary outcome was epilepsy, which was defined as ≥2 unprovoked seizures >24 hours apart, 1 unprovoked seizure and a chance of additional seizures following 2 unprovoked seizures over a 10-year period, and/or the diagnosis of epilepsy syndrome.
Of the 144 patients included in the study, only 87 survived beyond age 1 and were included in the final analysis. Approximately 21% of the cohort was diagnosed with cerebral palsy during the study period. The median age of patients who received an epilepsy diagnosis (n=8) was 4.9 (interquartile range 1.7-6.1). At 1-year follow-up, the cumulative incidence risk for epilepsy was 2% (95% CI, 0.6%-9%).
Significant differences were observed in the different neonatal seizure etiologies as they related to epilepsy frequency (hypoxic-ischemic encephalopathy [4%], ischemic stroke [5%], intracranial hemorrhage [17%], infection [50%], "other" [33%]; P =.03).
In addition, the cumulative incidence risk of epilepsy at age 5 in this cohort was 7% (95% CI, 3%-20%). Patients with an epilepsy diagnosis were more likely to be born preterm, have a brain injury, and be discharged from the hospital on an anti-seizure medication. These factors were no longer associated with epilepsy frequency following adjustment for seizure etiology (preterm birth [odds ratio (OR) 5.6; 95% CI, 0.7-43.1, Wald P =.1] and anti-seizure medication at discharge [OR 3.7; 95% CI, 0.6-24.2, Wald P =.2]).
Since MRI and EEG risk factors were retrospectively reviewed, the study was unable to analyze the temporal seizure burden or the volume of MRI injury, both of which may have provided greater insights into outcomes.
The investigators suggest that larger and longer multicenter studies are required “to determine precise risk factors for adverse outcomes and epilepsy, and to understand whether neonatal seizure management can alter the risk of epilepsy and childhood disabilities.”
Glass HC, Numis AL, Gano D, Bali V, Rogers EE. Outcomes after acute symptomatic seizures in children admitted to a neonatal neurocritical care service [published online April 19, 2018]. Pediatric Neurology. doi:10.1016/j.pediatrneurol.2018.03.016