Longitudinal Changes in Diffusion Tensor Imaging Following Mild Traumatic Brain Injury and Correlation With Outcome

Abstract

The chronic consequences of traumatic brain injury (TBI) may contribute to the increased risk for early cognitive decline and dementia, primarily due to diffusion axonal injury. Previous studies in mild TBI (mTBI) have been controversial in describing the white matter tract integrity changes occurring at acute and subacute post-injury. In this prospective longitudinal study, we aim to investigate the longitudinal changes of white matter (WM) using diffusion tensor imaging (DTI) and their correlations with neuropsychological tests. Thirty-three patients with subacute mTBI and 31 matched healthy controls were studied with an extensive imaging and clinical battery. Neuroimaging was obtained within 7 days post-injury for acute scans and repeated at 1 and 3 months post-injury. Using a region-of-interest-based approach, tract-based spatial statistics was used to conduct voxel-wise analysis on diffusion changes in mTBI and was compared to those of healthy matched controls, scanned during the same time period and rescanned with an interval similar to that of patients. We found decreased fractional anisotropy (FA) values in the left anterior limb of internal capsule (ALIC) and right inferior fronto-occipital fasciculus (IFOF) during the 7 days post-injury, which showed longitudinal evidence of recovery following 1 month post-injury. Increased FA values in these two tracts at 1 month post-injury were positively associated with better performance on cognitive information processing speed at initial assessment. By contrast, there were also some tracts (right anterior corona radiata, forceps major, and body of corpus callosum) exhibiting the continuing loss of integrity sustaining even beyond 3 months, which can predict the persisting post-concussion syndromes. Continuing loss of structural integrity in some tracts may contribute to the persistent post-concussion syndromes in mTBI patients, suggesting certain tracts providing an objective biomarker for tracking the pathological recovery process following mTBI.

Integrity of anterior corpus callosum is well related to language impairment after traumatic brain injury

“…In TBI, consistent decrease in anisotropic diffusion has been reported in the chronic phase after TBI. However, considerable debate remains if this occurs in the acute and sub-acute phases [13]. Although the CC is one of the predilection sites of traumatic axonal injury, it is believed to be unevenly affected after trauma [4,5].…”

White Matter Myelin Changes Related to Long-term Intensive Training in Japanese World-class Gymnasts

“…Finally, gymnastics requires difficult maneuvers and body postures that increase the risk of traumatic brain injury (TBI). Indeed, a mild TBI may also cause transient decreased FA 24) and myelin. 25) Unfortunately, neurologic examinations to provide evidence of TBI in J-WCGs and a longitudinal analysis to show the progress of white matter myelin changes in these gymnasts were not performed.…”

Differences in Corticoreticulospinal Tract Injuries According to Whiplash in Mild Traumatic Brain Injury Patients

“…Fourth, we recruited patients with chronic stage mTBI (i.e., more than 2 weeks after onset) and the average duration to DTI after onset was heterogeneous (14.0 ± 26.2 months) after TBI onset. As a result, recovery or degeneration of the CRT injuries during that interval may have influenced the results (43–45).…”