PT  - JOURNAL ARTICLE
AU  - Croall, Iain D.
AU  - Cowie, Christopher J.A.
AU  - He, Jiabao
AU  - Peel, Anna
AU  - Wood, Joshua
AU  - Aribisala, Benjamin S.
AU  - Mitchell, Patrick
AU  - Mendelow, A. David
AU  - Smith, Fiona E.
AU  - Millar, David
AU  - Kelly, Tom
AU  - Blamire, Andrew M.
TI  - White matter correlates of cognitive dysfunction after mild traumatic brain injury
AID  - 10.1212/WNL.0000000000000666
DP  - 2014 Aug 05
TA  - Neurology
PG  - 494--501
VI  - 83
IP  - 6
4099  - http://n.neurology.org/content/83/6/494.short
4100  - http://n.neurology.org/content/83/6/494.full
SO  - Neurology2014 Aug 05; 83
AB  - Objective: To relate neurophysiologic changes after mild/moderate traumatic brain injury to cognitive deficit in a longitudinal diffusion tensor imaging investigation.Methods: Fifty-three patients were scanned an average of 6 days postinjury (range = 1–14 days). Twenty-three patients were rescanned 1 year later. Thirty-three matched control subjects were recruited. At the time of scanning, participants completed cognitive testing. Tract-Based Spatial Statistics was used to conduct voxel-wise analysis on diffusion changes and to explore regressions between diffusion metrics and cognitive performance.Results: Acutely, increased axial diffusivity drove a fractional anisotropy (FA) increase, while decreased radial diffusivity drove a negative regression between FA and Verbal Letter Fluency across widespread white matter regions, but particularly in the ascending fibers of the corpus callosum. Raised FA is hypothesized to be caused by astrogliosis and compaction of axonal neurofilament, which would also affect cognitive functioning. Chronically, FA was decreased, suggesting myelin sheath disintegration, but still regressed negatively with Verbal Letter Fluency in the anterior forceps.Conclusions: Acute mild/moderate traumatic brain injury is characterized by increased tissue FA, which represents a clear neurobiological link between cognitive dysfunction and white matter injury after mild/moderate injury.AD=axial diffusivity; DAI=diffuse axonal injury; DTI=diffusion tensor imaging; FA=fractional anisotropy; GCS=Glasgow Coma Scale; MD=mean diffusivity; NART=National Adult Reading Test; RD=radial diffusivity; TBI=traumatic brain injury; TBSS=Tract-Based Spatial Statistics; TE=echo time; TR=repetition time; VLF=Verbal Letter Fluency