Fractional Anisotropy Abnormalities ID'd in Mild TBI
(HealthDay News) – Following mild traumatic brain injury (mTBI), diffusion tensor imaging (DTI) reveals abnormalities in white matter fractional anisotropy (FA) indicative of traumatic axonal injury, which vary between patients.
Michael L. Lipton, MD, of the Albert Einstein College of Medicine of Yeshiva University in New York City, and colleagues conducted a DTI study involving 34 patients with mTBI and 30 healthy controls. Participants underwent imaging at two weeks and at three and six months after injury. FA images were examined, and white matter diffusion abnormalities in individual patients were evaluated using Enhanced Z-score Microstructural Assessment for Pathology techniques.
The researchers found that there were areas of abnormally high or low FA, with the spatial pattern of abnormalities varying among patients and changing over time. Areas of low FA were found to be consistent with patterns of traumatic axonal injury. Areas of high FA were noted most frequently in deep and subcortical white matter of the frontal, parietal, and temporal lobes and parts of the corpus callosum. The unique pattern of FA abnormalities seen in each patient resulted from inter-individual differences in anatomy, vulnerability to injury, and mechanism of injury.
"This effective individual level assessment of mTBI yields patient-specific information," the authors write. "Such individual measurements can be used to assess the relationship of each patient's injury to their functional outcome, which is an essential step toward determining the utility of DTI as a prognostic biomarker, which might serve to guide future personalized medicine approaches to the treatment of mTBI."