Imaging Biomarkers for Outcomes in Mild TBI

Mild traumatic brain injury (mTBI) results in cognitive impairment (memory, attention, and executive function), post-concussion symptoms (PCS) and limitations in daily functioning.

Goal of this prospective longitudinal study:    
To identify early diffusion tensor imaging biomarkers of mTBI that significantly relate to outcomes at 1 year following injury.

Methods:
* Diffusion Tensor Imaging (DTI) was performed on 39 subjects with mTBI within 16 days of injury and 40 controls.
* 26 subjects with mTBI returned for follow-up at 1 year: Cognitive function, PCS, and HRQoL (health-related quality of life) were assessed.

Results:  

* Significant associations of brain-wide DTI measures and outcomes included the following:
(a) mean radial diffusivity and mean diffusivity with memory; and
(b) mean fractional anisotropy, radial diffusivity, and mean diffusivity with health-related quality of life.

* Significant differences in outcomes were found between subjects with and without abnormally high fractional anisotropy for the following white matter regions and outcome measures:
(a) left frontal lobe and left temporal lobe with attention at 1 year,
(b) left and right cerebelli with somatic postconcussion symptoms at 1 year, and
(c) right thalamus with emotional postconcussion symptoms at 1 year.

  Abnormally high fractional anisotropy is significantly associated with better outcomes and might represent an imaging correlate of postinjury compensatory processes.