Nonconvulsive Electrographic Seizures are Common in Children With Abusive Head Trauma

Objective: To determine the prevalence of nonconvulsive seizures in children with abusive head trauma. Design: Retrospective study of children with abusive head trauma undergoing clinically indicated continuous electroencephalographic monitoring. Setting: PICU of a tertiary care hospital. Subjects: Children less than or equal to 2 years old with evidence of abusive head trauma determined by neuroimaging, physical examination, and determination of abuse by the Child Protection Team. Interventions: None. Measurements and Main Results: Thirty-two children with abusive head trauma were identified with a median age of 4 months (interquartile range 3, 5.5 months). Twenty-one of 32 children (66%) underwent electroencephalographic monitoring. Those monitored were more likely to have a lower admission Glasgow Coma Scale (8 vs 15, p = 0.05) and be intubated (16 vs 2, p = 0.002). Electrographic seizures occurred in 12 of 21 children (57%) and constituted electrographic status epilepticus in 8 of 12 children (67%). Electrographic seizures were entirely nonconvulsive in 8 of 12 children (67%). Electroencephalographic background category (discontinuous and slow-disorganized) (p = 0.02) and neuroimaging evidence of ischemia were associated with the presence of electrographic seizures (p = 0.05). Subjects who had electrographic seizures were no more likely to have clinical seizures at admission (67% electrographic seizures vs 33% none, p = 0.6), parenchymal imaging abnormalities (61% electrographic seizures vs 39% none, p = 0.40), or extra-axial imaging abnormalities (56% electrographic seizures vs 44% none, p = 0.72). Four of 21 (19%) children died prior to discharge; none had electrographic seizures, but all had attenuated-featureless electroencephalographic backgrounds. Follow-up outcome data were available for 16 of 17 survivors at a median duration of 9.5 months following PICU admission, and the presence of electrographic seizures or electrographic status epilepticus was not associated with the Glasgow Outcome Scale score (p = 0.10). Conclusions: Electrographic seizures and electrographic status epilepticus are common in children with abusive head trauma. Most seizures have no clinical correlate. Further study is needed to determine whether seizure identification and management improves outcome.