Rethinking “Mild” Concussion in Early Childhood

In this issue of Pediatrics, Rose et al1 present the incidence of persisting symptoms after concussion (PSaC) in young children, a population historically underrepresented in concussion research. Their multicenter cohort study evaluated children aged 6 months to less than 6 years old presenting to emergency departments (EDs) in Canada and the United States for head injury compared with children who had isolated orthopedic injuries or were healthy community controls. Although nearly all had a Glasgow Coma Scale score of 15, inclusion required at least 1 concerning feature—palpable skull fracture, loss of consciousness, headache, or altered mental status—placing most in the intermediate-to-high risk categories of the PECARN head injury rule.2 Using caregiver reports on the Report of Early Childhood Traumatic Injury Observations and Symptoms (REACTIONS) and reliable change index (RCI) analysis, they found that 28% of children with concussion experienced PSaC at 1 month, 24% at 3 months, and 16% at 12 months, as compared with 10% of orthopedic controls and 2% of community controls. The only independent predictor of PSaC was total symptom burden at the initial ED visit.Children aged younger than 5 years have the highest rates of ED visits for head injuries, yet concussion in this population is often missed because of atypical symptoms and limited verbal abilities.3 Because they cannot reliably describe internal symptoms, clinicians must depend on caregiver observation. This study introduces a validated screening tool showing that more than 1 in 4 children have persistent behavioral changes 1 month after concussion. Persisting symptoms in early childhood have been linked to later physical, emotional, and academic challenges.4 These findings highlight the need for standardized screening and developmentally tailored follow-up for young children with PSaC.The first years of life are critical for establishing neural and developmental foundations, making unrecognized or undertreated brain injury especially consequential. As Beauchamp et al note, traumatic brain injuries (TBIs) in the very young have often been dismissed under the comforting but misguided assumption that neuronal plasticity ensures full recovery.5 Their message is clear: Neuronal plasticity is not nature’s Band-Aid. Injury in early childhood occurs during a period of rapid synaptic pruning and network reorganization, when even brief disruptions may alter developmental trajectories. Although the long-term impact of concussion in young children remains uncertain, the high proportion with symptoms 1 month postinjury underscored the importance of early detection, follow-up, and continued study to ensure recovery supports healthy development.A major strength of this study lies in its use of orthopedic controls and the RCI to isolate concussion-specific effects from the general stress of injury. Orthopedic controls account for the behavioral changes common to any trauma, while the RCI adds rigor by testing whether symptom change exceeds what would be expected by chance or normal variation. Using the orthopedic control group as the reference and the community control group for developmental context strengthens confidence that PSaC represents genuine postconcussive dysfunction. Still, even with these methods, the reported rates may be modestly inflated, as families most concerned about their child’s recovery are also the most likely to remain engaged in follow-up. The authors’ use of multiple imputation and sensitivity analyses helps minimize this bias.REACTIONS scores obtained in the ED were highly predictive of PSaC at 1 month. Other variables (eg, age, loss of consciousness, imaging, and parental education) did not predict persistence. The predictive value of the initial REACTIONS score may prove valuable in developing both diagnostic tools and follow-up strategies. Currently, most young children with mild TBI are discharged under the assumption of full spontaneous recovery, with little structured follow-up or anticipatory guidance. This study challenges those assumptions and encourages clinicians to reconsider which children may benefit from closer monitoring and continued support after a head injury.Interestingly, attending daycare or preschool was associated with a lower likelihood of persisting symptoms in unadjusted analyses, though this association disappeared after controlling for other variables. This finding raises important questions about how social environment and caregiver observation affect recovery. Structured routines, peer interaction, and caregiver support may help normalize behavior after injury—or, alternatively, daycare attendance may simply reflect greater family stability and access to resources. Parents of children in daycare may also spend fewer hours directly observing postinjury behavior, potentially reducing sensitivity to subtle symptoms. Understanding how environment and caregiver observation influence recovery warrants further study.Assessing preverbal children after head injury is challenging. This study shows that the REACTIONS tool provides a developmentally sensitive and practical way to identify concussion and stratify risk for persisting symptoms. Early identification supports a pragmatic, family-centered approach that builds on existing systems—the primary care home, early learning environment, and family routines. Brief follow-up visits, symptom check-ins, and age-appropriate “return-to-play” or “return-to-learn” guidance mirror the structured, symptom-guided care routinely provided for older children after concussion. REACTIONS could be readily adopted in acute and primary care settings to standardize postinjury monitoring. By engaging the medical home in monitoring, clinicians can help families set a recovery baseline, recognize when symptoms interfere with development, and connect to existing early intervention or support services as needed.Future studies should refine predictive models that minimize bias from caregiver anxiety or subjective reporting and incorporate objective markers such as sleep, activity, or physiologic measures of recovery. Because early childhood represents a period of rapid neural development and vulnerability, understanding how biological and environmental factors interact to shape outcomes remains a priority. Emerging research in blood and saliva biomarkers offers an opportunity to link observable behavior with underlying neurobiologic recovery, providing an objective window into healing in children unable to self-report. Longitudinal studies are essential to understand and mitigate the long-term effects of early brain injury.A key limitation of this study is the use of the same caregiver-reported tool to measure both initial symptoms and outcomes, which may inflate associations because data come from the same source. The use of the RCI helps mitigate this by identifying changes that exceed normal variability, strengthening confidence that differences reflect true clinical change. Reliance on caregiver reporting is unavoidable in preverbal children, but orthopedic controls help account for caregiver stress and observation bias. Parental concern may also contribute to persistent symptoms through a nocebo-like effect, wherein expectations shape perception and reporting. Although the sample size and geography limit generalizability, the findings align with prior research and represent a critical step in closing this gap. Future studies incorporating clinician, physiologic, and biomarker data could help distinguish recovery from perception-driven symptom persistence.This study affirms that “mild injury” and “no injury” are not synonymous. Although pediatric care has long trusted the healing power of time and neural plasticity, these findings show that time alone is not always enough. PSaC is real, although its long-term significance is uncertain. What is clear is that young children deserve the same structured, symptom-guided follow-up that is already standard for older children and adolescents. Simple, developmentally informed interventions could help identify those who are slow to recover and prevent lasting effects. The REACTIONS tool provides a practical foundation for early assessment and monitoring, allowing clinicians to track progress and identify persistent dysfunction. As research advances, biomarkers may complement these behavioral measures, linking observed symptoms with underlying neurobiologic recovery. Those tools—and our vigilance—should be focused on the youngest patients, whose futures may depend on it.