Citation

Oehr LE, Yang JYM, Chen J, Maller J, Seal M, Anderson J. J. Neurotrauma 2020; ePub(ePub): ePub.

Copyright

(Copyright © 2020, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2020.7310

PMID

33307950

Abstract

Using diffusion-weighted imaging (DWI), research has demonstrated changes suggestive of damage to white matter tracts (WMT) following mild traumatic brain injury (mTBI). Yet due to the predominant use of the diffusion-tensor imaging (DTI) model, which has numerous well-established limitations, it has not yet been possible to clearly examine the nature of changes to WMT microstructure following mTBI. This study used a second DWI-based technique, Neurite Orientation Dispersion and Density Imaging (NODDI), in combination with DTI to measure microstructural changes within the corpus callosum, three long association and one projection WMTs at 6-12 weeks following mTBI, compared to matched trauma controls (TC). Between-groups differences were identified across all WMT for the DTI metric, fractional anisotropy (FA), and the NODDI metrics, orientation dispersion index (ODI) and isotropic volume fraction (ISO). No statistically significant between-groups differences were found for other DTI and NODDI metrics. Our study revealed that reduced FA was accompanied by increased ODI, suggesting that mTBI results in reduced coherence of axonal fibre bundles within the studied WMTs. These between-groups differences in WMT microstructure were found at 6-12 weeks post-injury, which suggests that structural recovery is not yet complete towards end of the typical 3-month recovery period.

Language: en

Keywords

TRAUMATIC BRAIN INJURY; AXONAL INJURY; Diffusion Tensor Imaging