Objectives: Most children recover from mild traumatic brain injury (mTBI), but some experience persistent neurocognitive effects. Understanding is limited due to methodological differences and a lack of pre-injury data. The study aimed to assess changes in neurocognitive outcomes in children following mTBI compared to orthopedic injury (OI) and non-injured (NI) controls, while accounting for pre-injury functioning.
Method: Data were drawn from the Adolescent Brain and Cognitive Development (ABCD) study, a prospective longitudinal cohort. The sample included children with mTBI between the 1-year and 2-year follow-ups (n = 83), identified by parent report of head injury with memory loss or loss of consciousness, compared to children who experienced OI within the same period (n = 231) and an NI control group (n = 218). Changes in neurocognitive outcomes from baseline to the 2-year follow-up between groups (mTBI vs. OI; mTBI vs. NI) were estimated using linear mixed-effects models, accounting for demographic, behavioral, genetic, and white matter microstructural covariates.
Results: At baseline prior to injury, the mTBI group demonstrated better performance on picture vocabulary and crystallized composite scores than the OI group. At post-injury, after adjusting for pre-injury baseline differences, children who sustained an mTBI were no different in any measure of neurocognitive outcomes compared to OI and NI controls.
Conclusions: The findings highlight the importance of accounting for pre-injury differences when evaluating neurocognitive outcomes following pediatric mTBI. Neurocognitive differences within a year post-injury may be more related to pre-existing individual factors rather than the injury itself, underscoring the need for a comprehensive approach in studying pediatric mTBI.
Keywords: Pediatric traumatic brain injury; cognition; concussion; control group comparison; longitudinal analysis; pre-injury functioning.