Neuroanatomical Substrates and Symptoms Associated With Magnetic Resonance Imaging of Patients With Mild Traumatic Brain Injury

This multicenter cohort study assesses neuroanatomical substrates in patients with mild traumatic brain injury and the optimal timing for magnetic resonance imaging. Question What neuroanatomical changes are associated with symptoms after mild traumatic brain injury (mTBI), and when is the optimal time for acute imaging? Findings In this multicenter cohort study, 81 patients with mTBI underwent advanced magnetic resonance imaging within 72 hours and 2 to 3 weeks after injury. White matter volume and integrity evolved during that window in tandem with symptoms and were most closely associated with clinical recovery if imaging was performed within 72 hours. Meaning These findings suggest that white matter injury is associated with symptoms after mTBI and could, if detected early, help select patients at risk of poor outcome for clinical follow-up or interventional trials. Importance Persistent symptoms after mild traumatic brain injury (mTBI) represent a major public health problem. Objective To identify neuroanatomical substrates of mTBI and the optimal timing for magnetic resonance imaging (MRI). Design, Setting, and Participants This prospective multicenter cohort study encompassed all eligible patients from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study (December 19, 2014, to December 17, 2017) and a local cohort (November 20, 2012, to December 19, 2013). Patients presented to the hospital within 24 hours of an mTBI (Glasgow Coma Score, 13-15), satisfied local criteria for computed tomographic scanning, and underwent MRI scanning less than 72 hours (MR1) and 2 to 3 weeks (MR2) after injury. In addition, 104 control participants were enrolled across all sites. Data were analyzed from January 1, 2019, to December 31, 2020. Exposure Mild TBI. Main Outcomes and Measures Volumes and diffusion parameters were extracted via automated bespoke pipelines. Symptoms were measured using the Rivermead Post Concussion Symptoms Questionnaire in the short term and the extended Glasgow Outcome Scale at 3 months. Results Among the 81 patients included in the analysis (73 CENTER-TBI and 8 local), the median age was 45 (interquartile range [IQR], 24-59; range, 14-85) years, and 57 (70.4%) were male. Structural sequences were available for all scans; diffusion data, for 73 MR1 and 79 MR2 scans. After adjustment for multiple comparisons between scans, visible lesions did not differ significantly, but cerebral white ma