Early WM Alterations after Mild Traumatic Brain Injury: An Exploratory Study Using Quantitative MRI and DTI

The purpose was to investigate early WM alterations in patients with mild traumatic brain injury (mTBI) within 1 week of trauma using quantitative MRI and DTI.

This cross-sectional study included 31 patients with mTBI and 36 healthy controls. Neuropsychological assessment and MRI scans were performed within 1 week of trauma. ROIs were selected from 4 WM regions: superior longitudinal fasciculus, anterior limb of the internal capsule, posterior limb of the internal capsule, and external capsule. Quantitative MRI and DTI were used to assess WM alterations. Correlation analyses explored relationships between WM alterations and clinical outcomes.

Compared with controls, patients with mTBI demonstrated lower scores on the Montreal Cognitive Assessment, particularly in the domains of abstraction, delayed recall memory, and orientation. Higher T1 values were detected in the left posterior limb of the internal capsule, whereas elevated proton density (PD) values were found in the right external capsule, bilateral superior longitudinal fasciculus, and posterior limb of the internal capsule. No significant differences in T2 or fractional anisotropy were observed. PD values in the left posterior limb of the internal capsule were negatively correlated with attention and language scores in patients with mTBI.

In conclusion, quantitative MRI may detect subtle WM alterations in the acute stage of mTBI. No notable between-group differences were observed in the DTI parameters in the current cohort. Larger longitudinal studies are needed to determine the reproducibility, temporal evolution, and clinical relevance of these findings.