A voxel-based meta-analysis of diffusion tensor imaging in mild traumatic brain injury

Microstructural damage to white matter and resultant abnormal structural connectivity are a potential underlying pathophysiological mechanism of mild traumatic brain injury (mTBI). Many Tract-Based Spatial Statics studies have investigated the pathophysiology of mTBI, but they yielded inconsistent results potentially due to insufficient statistical power in spite of methodological homogeneity. We used anisotropic effect size signed differential mapping (AES-SDM) to integrate previous studies that recruited patients without a psychiatric history. AES-SDM revealed that fractional anisotropy values were significantly lower in mTBI patients than in control in three clusters. The peak of the largest cluster was in the left thalamus and the cluster extended to the splenium of the corpus callosum and to the anterior thalamic radiation. The second largest cluster was situated in the left forceps minor, and the third largest cluster was in the right superior longitudinal fasciculus III. These results suggest that the pathophysiology of mTBI includes abnormal structural connectivity between the thalamus and the prefrontal cortex, and abnormal intra- and inter-hemispheric structural connectivity involving the prefrontal cortex.