A common feature of mild traumatic brain injury is damage to the white matter tracts that connect one part of the brain to another, or diffuse axonal injury (DAI). DAI is difficult to see in the traditional CT or MRI scans, and while it can be detected using newer technology such as diffusion tensor imaging, these technologies are not yet in clinical practice.
A research team recently hypothesized that certain white matter tracts related to eye movement were frequently damaged in mTBI, and that impaired eye movements could therefore be a reliable clinical marker for mTBI. They tested mTBI patients using a visual tracking device, measuring how smoothly their eyes moved to track a target.
Not only did the mTBI patients show decreased performance in the visual tracking task, but that decreased performance was correlated with white matter damage seen in a diffusion tensor imaging scan. The relatively easy to administer visual tracking task could therefore be used in lieu of diffusion tensor imaging in order to detect DAI related to mTBI.
Visual tracking synchronization as a metric for concussion screening. Maruta J, Suh M, Niogi SN, et al. Visual tracking synchronization as a metric for concussion screening. Journal of Head Trauma Rehabilitation. (July 2010).