Diffusion tensor imaging

The most common yet most controversial neurologic injury is mild traumatic brain injury (mTBI), which may have an annual incidence rate as high as 653/100,000.¹ Most mTBI cases have a positive outcome; the controversy exists in whether lasting sequelae occur. Typically, the neurologic examination is negative other than subtle cognitive complaints and subjective symptoms (e.g., headache, dizziness), as is conventional brain imaging. After head injury, the absence of definitive findings and a Glasgow Coma Score at or above 13 is the standard that defines mTBI.

There has been an active search for biomarkers of mTBI for clinical or research purposes. Conventional neuroimaging may reveal contusion or hemorrhage—referred to as complicated mTBI—however, such findings occur in fewer than 20% of mTBI cases evaluated in an emergency department,² minimizing its utility. CNS-related serum proteins have been identified in mTBI, but have proven unsuccessful as biomarkers. Variables such as loss of consciousness (LOC) and duration of posttraumatic amnesia (PTA) are important in assessing mTBI and its outcome, but outside of a research setting, LOC and PTA are difficult to identify and verify. The above-mentioned physical or neurocognitive symptoms associated with mTBI are nondescript, so they too lack specificity as objective markers. Without an accurate …