Twenty-five patients with TBI were recruited from Parkland Memorial Hospital, Dallas, Texas. Inclusion criteria required that patients: 1) sustain closed head traumatic brain injury through a mechanism consistent with TAI (such as high-speed motor vehicle collision), 2) were at least 16 years old. Exclusion criteria were: 1) preexisting neurologic disorders or prior history of TBI, 2) presence of focal lesions (including contusion, extra-axial hematoma, and/or intraparenchymal hemorrhages) with volume greater than 10ml visible on cranial CT, 3) conditions which may result in abnormal MRI findings and compromise cognitive functions (i.e., prior brain tumor, epilepsy, multiple sclerosis, encephalitis/meningitis, Parkinson’s Alzheimer’s disease/mild cognitive impairment, HIV encephalopathy, vascular malformation and psychiatric disease), 4) prisoners, homeless patients, and pregnant women. All patients demonstrated subcortical white matter lesions visible on T2 FLAIR MRI. Sixteen healthy volunteers of similar age- and gender were recruited as controls. All healthy volunteers had good general health and no known neurocognitive disorders. Informed consent was obtained from all participants or their legally authorized representative.
