OBJECTIVE We examined whether mild traumatic brain injuries in children and adolescents, especially when associated with acute clinical features reflecting more severe injury, result in different postinjury trajectories of postconcussive symptoms compared with mild orthopedic injuries. PARTICIPANTS AND METHODS Participants in this prospective and longitudinal cohort study were 8- to 15-year-old children, 186 with mild traumatic brain injuries and 99 with mild orthopedic injuries, who were recruited from consecutive admissions to emergency departments in 2 large children’s hospitals. Parents rated current postconcussive symptoms within 3 weeks of injury and at 1, 3, and 12 months after injury. At the initial assessment, parents also provided retrospective ratings of preinjury symptoms, and children with mild traumatic brain injuries received MRI of the brain. Clinical features examined as predictors of postconcussive symptoms included loss of consciousness, Glasgow Coma Scale score below 15, other injuries, acute symptoms of concussion, and intracranial abnormalities on the MRI. RESULTS Finite mixture modeling identified 4 longitudinal trajectories of postconcussive symptoms (ie, no postconcussive symptoms, moderate persistent postconcussive symptoms, high acute/resolved postconcussive symptoms, high acute/persistent postconcussive symptoms). The mild traumatic brain injuries and orthopedic injuries groups demonstrated a different distribution of trajectories. Children with mild traumatic brain injuries were more likely than those with orthopedic injuries to demonstrate high acute/resolved and high acute/persistent trajectories relative to the no postconcussive symptoms group. The 2 trajectories with high acute levels of postconcussive symptoms were especially likely among children with mild traumatic brain injuries whose acute clinical presentation reflected more severe injury. CONCLUSIONS Mild traumatic brain injuries, particularly those that are more severe, are more likely than orthopedic injuries to result in transient or persistent increases in postconcussive symptoms in the first year after injury. Additional research is needed to elucidate the range of factors, both injury related and non–injury related, that place some children with mild traumatic brain injuries at risk for postconcussive symptoms.

To investigate post-concussive symptoms (PCS) following mild pediatric traumatic brain injury (mTBI), 8-to 15-year old children with mTBI (n=186) and a comparison group with uncomplicated orthopedic injuries (OI, n=99) were recruited from two emergency departments. Parent and child ratings of PCS and symptom counts were obtained within 3 weeks after injury (baseline) and at 1, 3, and 12 months post injury. The mTBI group also completed magnetic resonance imaging (MRI) at baseline. Group differences were examined using growth modeling, controlling for age at injury, sex, socioeconomic status (SES), and (for parent-based measures) preinjury symptom levels. Relative to the OI group, the mTBI group had higher ratings of somatic PCS and parent counts of PCS at the initial assessments, but higher parent ratings of cognitive PCS and child counts of PCS throughout follow-up. Higher levels of PCS in the mTBI group were associated with motor-vehicle-related trauma, loss of consciousness, neuroimaging abnormalities, and hospitalization. The findings validate both transient and persistent PCS in children with mTBI and document associations of symptoms with injury and non-injury factors.

The occurrenceof postconcussive symptoms (PCS) following mild traumatic brain injury (TBI) in children may depend on cognitive reserve capacity. This prospective, longitudinal study examined whether the relationship between mild TBI and PCS is moderated by cognitive ability, which served as a proxy for cognitive reserve. Participants included 182 children with mild TBI and 99 children with orthopedic injuries (OI), ranging from 8 to 15 years of age when injured. Mild TBI were classified as complicated (n = 32) or uncomplicated (n = 150) depending on whether they were associated with trauma-related intracranial abnormalities on magnetic resonance imaging. PCS were assessed initially within 3 weeks of injury, and again at 1, 3, and 12 months post injury. The initial assessment also included standardized tests of children's cognitive skills and retrospective parent ratings of pre-injury symptoms. Hierarchical linear modeling indicated that ratings of PCS were moderated jointly by cognitive ability and injury severity. Children of lower cognitive ability with a complicated mild TBI were especially prone to cognitive symptoms across time according to parents and to high acute levels of PCS according to children's self-ratings. Cognitive reserve is an important moderator of the outcomes of mild TBI in children and adolescents.