Comprehensive Summary
This review, presented by Mourad et al. (2025), provides an overview of advanced quantitative methods for image analysis to examine various changes in brain pathology such as in brain structure, neural network integrity, and functional connectivity in a patient who has experienced mild traumatic brain injury (mTBI) and how it impacts their outcomes. They focus more on mTBI patients with persistent symptoms that undergo both neuropsychological assessments and advanced neuroimaging. Currently, traditional neuropsychological assessments only identify changes within the timeframe of acute mTBI. When measures are considered to be within normal limits (WML), they assume this means there is no lasting impairment. They examined group studies in which advanced imaging and neuropsychological evaluations were used to measure changes in brain pathology and find correlations with particular clinical outcomes. However, they found that in many cases, the brain after mTBI can still have residual pathology and restructuring found in advanced neuroimaging despite their WNL neuropsychological test results. While cases vary due to the heterogeneity of mTBI, some alterations that were found would include white-matter microstructure alterations, functional connectivity disruptions, and volumetric thinning. Based on their findings, they conclude that traditional neuropsychological assessments are not sufficient for a comprehensive evaluation of mTBI, particularly when these tests are deemed to be WNL. Despite the various advanced neuroimaging methods discussed in the review, they underline the importance of multimodality approaches to account for the heterogeneity of mTBI, biomechanics differences in the injury, and individual patient characteristics. Additionally, they note that no single imaging method currently captures all aspects of residual neuropathology in chronic mTBI cases.
Outcomes and Implications
This research is crucial as accurate mTBI evaluations are necessary to identify when patients experience lasting functional symptoms despite normal results in standard neuropsychological testing. It also underscores how advanced neuroimaging can reveal the neurobiological impact of mTBI that is routinely missed by conventional assessments. These findings highlight the need for more comprehensive diagnostic tools to detect subtle brain alterations that contribute to chronic symptoms post-mTBI. By incorporating more advanced, multimodal neuroimaging into clinical evaluations, physicians may be able to more accurately diagnose and treat patients who would otherwise be considered recovered. Since many heterogeneous factors influence mTBI, it is difficult to achieve a specific and singular neuroimaging biomarker. However, multimodal mTBI-associated neuroimaging biomarkers may arise as part of a more comprehensive evaluation of mTBI neuroimaging findings.