Age-specific risks of midline shift and neurosurgical intervention in small traumatic brain injuries in the United States: a retrospective cohort study

Purpose: Traumatic brain injury (TBI) is a leading cause of morbidity and mortality, particularly in older adults, in whom age-related physiological changes influence injury response and recovery. Smaller-volume TBIs, including subdural hematomas (≤8 mm), epidural hematomas (≤8 mm), and contusions (≤2 cm), are generally considered less severe; however, their clinical impact varies with age. This study aims to assess the effect of age on clinical outcomes, specifically midline shift and neurosurgical interventions, in patients with isolated, smaller-volume blunt TBIs.Methods: This retrospective registry-based cohort study analyzed American College of Surgeons (ACS) Trauma Quality Improvement Program (TQIP) Participant Use File data from 2017 to 2022. Patients aged ≥40 years with isolated smaller-volume TBIs were categorized into middle-aged (40–65 years) and older adult (≥65 years) groups. Multivariate logistic regression assessed associations between age, TBI type, midline shift, and neurosurgical interventions, adjusting for demographic, clinical, and injury-related variables.Results: Among 135,343 patients, older adults with small contusions were 68% lower odds to experience a midline shift (adjusted odds ratio [OR], 0.32; 95% CI, 0.23–0.43; P<0.01). They also had significantly lower odds of undergoing craniotomy (epidural hematomas: adjusted OR, 0.60 [95% CI, 0.37–0.95], P=0.03; contusions: adjusted OR, 0.11 [95% CI, 0.05–0.23], P<0.01) or intracranial pressure monitoring (contusions: adjusted OR, 0.36; 95% CI, 0.18–0.75; P<0.01) compared to middle-aged patients.Conclusion: Older adults with smaller TBIs are less likely to experience midline shift or undergo neurosurgical intervention. These findings emphasize the need for age-specific management strategies and suggest that a less aggressive intervention approach may be appropriate for older adults with smaller TBIs. Existing guidelines may require age-specific revisions. Further research is needed to explore long-term outcomes.