Eur J Neurosci. 2021 Mar 23. doi: 10.1111/ejn.15199. Online ahead of print.
ABSTRACT
Emotion regulation is related to recovery after mild traumatic brain injury (mTBI). This longitudinal tractography study examined white matter tracts subserving emotion regulation across the spectrum of mTBI, with a focus on persistent symptoms. Four groups were examined: (1) symptomatic (n=33) and (2) asymptomatic (n=20) patients with uncomplicated mTBI (i.e., no lesions on computed tomography (CT)), (3) patients with CT-lesions in the frontal areas (n=14), and (4) healthy controls (n=20). Diffusion and conventional MRI were performed approximately one and three months post-injury. Whole brain deterministic tractography followed by region of interest analyses were used to identify forceps minor, uncinate fasciculus, and cingulum bundle as tracts of interest. An adjusted version of the ExploreDTI Atlas Based Tractography method was used to obtain reliable tracts for every subject. Mean fractional anisotropy (FA), radial and axial diffusivity (MD, RD, AD), and number of streamlines were studied per tract. Linear mixed models showed lower FA, and higher MD, and RD of the right uncinate fasciculus in asymptomatic patients with uncomplicated mTBI relative to symptomatic patients and healthy controls. Diffusion alterations were most pronounced in the group with frontal lesions on CT, particularly in the forceps minor and uncinate fasciculus; these effects increased over time. Within the group of patients with uncomplicated mTBI, there were no associations of diffusion measures with number of symptoms nor with lesions on conventional MRI. In conclusion, mTBI can cause microstructural changes in emotion regulation tracts, however, no explanation was found for the presence of symptoms.
PMID:33759227 | DOI:10.1111/ejn.15199
