Usefulness of Diffusion Tensor Imaging for Evaluation of Motor Function in Patients With Traumatic Brain Injury

OBJECTIVES: To determine whether diffusion tensor imaging (DTI) can detect diffuse axonal injury, and to evaluate the association of DTI findings with motor function in patients with traumatic brain injury. DESIGN: Three case studies. SETTING: An inpatient rehabilitation unit in Korea. PARTICIPANTS: Three patients with traumatic brain injury in whom conventional neuroimaging showed normal-appearing white matter. MAIN OUTCOME MEASURES: Patients were studied with DTI. Fractional anisotropy (FA) was measured from 3 different anatomic locations on both sides of the corticospinal tract. Motor function was evaluated using the motoricity index. RESULTS: Fractional anisotropy tended to be reduced in normal-appearing corticospinal tracts that were remote from the involved segment. Diffusion tensor imaging showed reduction of FA in areas consistent with motor dysfunction. CONCLUSION: Fractional anisotropy of the corticospinal tract may be used in the detection of diffuse axonal injury. The association between decreased motoricity index and decreased FA suggests that DTI may be useful in evaluating patients with traumatic brain injury.