Diffusion-tensor imaging implicates prefrontal axonal injury in executive function impairment following very mild traumatic brain injury

Radiology. 2009 Sep;252(3):816-24. doi: 10.1148/radiol.2523081584. Epub 2009 Jun 30.


Purpose: To determine whether frontal white matter diffusion abnormalities can help predict acute executive function impairment after mild traumatic brain injury (mTBI).

Materials and methods: This study had institutional review board approval, included written informed consent, and complied with HIPAA. Diffusion-tensor imaging and standardized neuropsychologic assessments were performed in 20 patients with mTBI within 2 weeks of injury and 20 matched control subjects. Fractional anisotropy (FA) and mean diffusivity (MD) images (imaging parameters: 3.0 T, 25 directions, b = 1000 sec/mm(2)) were compared by using whole-brain voxelwise analysis. Spearman correlation analyses were performed to evaluate associations between diffusion measures and executive function.

Results: Multiple clusters of lower frontal white matter FA, including the dorsolateral prefrontal cortex (DLPFC), were present in patients (P < .005), with several clusters also demonstrating higher MD (P < .005). Patients performed worse on tests of executive function. Lower DLPFC FA was significantly correlated with worse executive function performance in patients (P < .05).

Conclusion: Impaired executive function following mTBI is associated with axonal injury involving the DLPFC.

MeSH terms

  • Accidental Falls
  • Accidents, Traffic
  • Adult
  • Anisotropy
  • Case-Control Studies
  • Chi-Square Distribution
  • Cognition Disorders / pathology*
  • Diffuse Axonal Injury / pathology*
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prefrontal Cortex / injuries*