Objective
Traumatic brain injury (TBI) causes substantial morbidity and mortality in children. Post-traumatic seizures (PTS) may worsen outcomes after TBI. PTS risk factors are incompletely understood. Our objective was to clarify PTS risk factors in a large cohort of children with severe TBI.
Design
Retrospective cohort study of a probabilistically linked dataset from the National Trauma Data Bank (NTDB) and the Pediatric Health Information Systems (PHIS) database, 2007–2010
Setting
29 U.S. children’s hospitals
Patients
2,122 children (age < 18 years old at admission) with linked NTDB and PHIS records, severe (Emergency Department [ED] Glasgow Coma Scale [GCS] < 8) TBI, hospital length of stay > 24 hours, and non-missing disposition
Interventions
None
Measurements and Main Results
The outcome was PTS, identified using validated ICD-9-CM diagnosis codes. Pre-specified candidate predictors of PTS included age, injury mechanism, ED GCS, intracranial hemorrhage type, hypoxia, hypotension, and cardiac arrest. PTS were diagnosed in 25.2% of children with severe TBI. In those without abuse/assault or subdural hemorrhage (SDH), the PTS rate varied between 36.6% in those < 2 years old and 16.4% in those 14–17 years old. Age, abusive mechanism, and subdural hemorrhage (SDH) are each significant predictors of PTS. The risk of PTS has a complex relationship with these predictors. The estimated odds of PTS decrease with advancing age, OR = 0.929 (0.905, 0.954) per additional year of age with no abuse/assault and no SDH; OR = 0.820 (0.730, 0.922) per additional year of age when abuse and SDH are present. An infant with accidental TBI and SDH has approximately the same estimated probability of PTS as an abused infant without SDH, 47% (95% CI: 39%, 55%) versus 50% (95% CI: 41%, 58%), P = 0.69. The triad of young age, injury by abuse/assault, and SDH confers the greatest estimated probability for PTS, 60% (95% CI: 53%, 66%).
Conclusions
PTS risk in children with severe TBI is greatest with a triad of younger age, injury by abuse/assault, and SDH. However, PTS is common even in the absence of these factors.