Short-term DTI predictors of cognitive dysfunction in mild traumatic brain injury

Primary objective: To explore whether baseline diffusion tensor imaging (DTI) metrics are predictive of cognitive functioning 6 months post-injury in patients with mild traumatic brain injury (MTBI). Research design: Seventeen patients with MTBI and 29 sex- and age-matched healthy controls were studied. Methods and procedures: Participants underwent an MRI protocol including DTI, at an average of 4.0 (range: 1-10) days post-injury. Mean diffusivity (MD) and fractional anisotropy (FA) were measured in the following white matter (WM) regions: centra semiovale, the genu and the splenium of the corpus callosum and the posterior limb of the internal capsule. Participants underwent neuropsychological (NP) testing at baseline and at 6-month follow-up. Least squares regression analysis was used to evaluate the association of MD and FA with each NP test score at baseline and follow-up. Main outcomes and results: Compared to controls, average MD was significantly higher (p = 0.02) and average FA significantly lower (p = 0.0001) in MTBI patients. At the follow-up, there was a trend toward a significant association between baseline MD and response speed (r = -0.53, p = 0.087) and a positive correlation between baseline FA and Prioritization form B (r = 0.72, p = 0.003). Conclusions: DTI may provide short-term non-invasive predictive markers of cognitive functioning in patients with MTBI.