Personal Injury Law

Diffusion Tensor Imaging and Mild Traumatic Brain Injury

By Bruce Stern

I recently read with great interest a new research study entitled “Extent of Microstructural White Matter Injury in Post-Concussive Syndrome Correlate with Impaired Cognitive Reaction Time: A 3-T Diffusion Tensor Imaging Study of Mild Traumatic Brain Injury” which appeared in the May 2008 issue of the American Journal of NeuroRadiology (29:967-73) (May 2008).

The article begins by acknowledging that patients with mild traumatic brain injury often have normal CT findings. It also acknowledges that 30% of patients with post-traumatic amnesia have persistent post-traumatic symptoms and that a significant number continue to have decreased functional outcome one year post-injury. There is also a wonderful quote that reads “Sequellae of TBI cause significant disability which compelled the National Institutes of Health to declare mild TBI as a major public health problem,” citing two Ragnarsson” paper entitled “Results of the NIH Consensus Conference on Rehabilitation of Persons with Traumatic Brain Injury,” Restor Neurol Neurosci 2002; 20:103-08, which puts to rest arguments that everyone gets better following mild traumatic brain injury.

The purpose of the study was to determine whether diffusion tensor imaging (DTI) would be a useful index of microstructural changes implicated in diffuse axonal injury linked to persistent post-concussive symptoms, especially mild traumatic brain injury for which conventional MRI lacks sensitivity. The author’s hypothesis, “[F]or mild TBI, DTI measures of DAI would correlate with impairments in reaction time, whereas the number of focal lesions on conventional 3T MRI would not.”

The researchers included thirty-four adult patients with mild TBI who had persistent symptoms which were assessed for DAI by quantifying traumatic microimages detected on a conventional set of T2 weighted gradient-echo images and by DTI measures of fractional anisotropy within a set of eight priority regions of interest. Twenty-six healthy control adults were also used.

The authors report that DTI measures revealed several prominent regions of damage. The authors concluded that microstructural white matter lesions detected by DTI correlated with persistent cognitive deficits in mild TBI, even in populations in which conventional measures did not. The authors concluded that DTI measures may thus contribute additional diagnostic information related to DAI. For those neuroattorneys looking to objectively document the diagnosis of mild traumatic brain injury, this original research paper contributes greatly.

Full post as published by Traumatic Brain Injury Law Blog on June 16, 2008 (boomark / email).