Risk factors for epilepsy in children with neonatal encephalopathy

Abstract

We examined neonatal predictors of epilepsy in term newborns with neonatal encephalopathy (NE) by studying children enrolled in a longitudinal, single center cohort study. Clinical data were obtained through chart review, and MRI was performed in the neonatal period. We administered a seizure questionnaire to parents of children aged ≥ 12 mo (range, 12 mo to 16.5 y) to determine the outcome of epilepsy. The association between clinical predictors and time to onset of epilepsy was assessed using Cox proportional hazards regression. Thirteen of 129 children developed epilepsy: all had neonatal seizures and brain injury on neonatal MRI. Of the newborns with neonatal seizures, 25% (15.8/1000 person-years) developed epilepsy, with the highest hazard ratios (HRs) in the newborns with status epilepticus (HR, 35.8; 95% CI, 6.5-196.5). Children with severe or near-total brain injury were more likely to develop epilepsy compared with those with only mild or moderate injury (HR, 5.5; 95% CI, 1.8-16.8). In a multivariable analysis adjusting for degree of encephalopathy and severe/near-total brain injury, status epilepticus was independently associated with epilepsy. These data add to information regarding epilepsy pathogenesis and further aid clinicians to counsel parents regarding the likelihood that a newborn with NE will develop epilepsy.

Figure 1

Kaplan-Meier estimates for epilepsy-free survival among 129 newborns with neonatal encephalopathy, with and without neonatal seizures. No seizures: solid line (N=76); clinical seizures only: dashed line (N=28), EEG confirmed seizures: dotted line (N=19); status epilepticus: dash-dot line (N=6).

Figure 2

Kaplan-Meier estimates for epilepsy-free survival among 129 newborns with neonatal encephalopathy, with and without brain injury. No injury: solid line (N=42); mild/moderate injury: dashed line (N=65); severe/near total injury; dotted line (N=22).