Diffusion Tensor Imaging and Neuropsychological Testing
In the most current issue of the Journal of Head Trauma Rehabilitation (Vol. 25, No. 1, pp. 31-42), Rakesh K. Gupta, M.D. and his colleagues in Locknow, India, studied the correlation and changes in diffusion tensor imaging with neuropsychometric tests ( NPT)in patients with moderate traumatic brain injury.
The objective of the study was to assess longitudinally the severity of DAI in the corpus callosum with patients with moderate traumatic brain injury through DTI and to correlate those changes with neuropsychometric tests at 6 and 24 months after injury. Sixteen patients with traumatic brain injury were matched with 17 age/sex matched healthy controls. The patients underwent MRI at 2 weeks, 6 months and 24 months after injury. Neuropsychometric testing was performed at 6 and 24 months.
The authors found that fractional anisotropy in genu as well as insignificant decrease in radial diffusivity and mean diffusivity values in genu and splenium were observed over time. Although some neuropsychometric test scores improved over time with these patients, they were still significantly impaired when compared with controls.
The researchers concluded that the FA and RD indices appeared to be surrogate markers of microstructural alterations in patients and did correlate significantly with some of the NPT scores. The researches found that these indices may be used as an objective marker for residual injury in these patients.
This study is important because it provides objective proof of injury, shows correlation between neuropsychological testing and DTI and contrasts earlier studies finding that patients over time showed no demonstrable findings on NPT.