Use of diffusion tensor imaging to examine subacute white matter injury progression in moderate to severe traumatic brain injury.

OBJECTIVE

To demonstrate subacute progression of white matter (WM) injury (4.5mo-2.5y postinjury) in patients with traumatic brain injury using diffusion-tensor imaging.

DESIGN

Prospective, repeated-measures, within-subjects design.

SETTING

Inpatient neurorehabilitation program and teaching hospital MRI department.

PARTICIPANTS

Brain-injured adults (N=13) with a mean Glasgow Coma Scale score of 7.67+/-4.16.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Fractional anisotropy (FA) values were measured at 4.5 and 29 months postinjury in right and left frontal and temporal deep WM tracts and the anterior and posterior corpus callosum.

RESULTS

FA significantly decreased in frontal and temporal tracts: right frontal (.38+/-.06 to .30+/-.06; P<.005), left frontal (.37+/-.06 to .32+/-.06; P<.05), right temporal (.28+/-.05 to .22+/-.018; P<.005), and left temporal (.28+/-.05 to .24+/-.02; P<.05). No significant changes were in the corpus callosum.

CONCLUSIONS

Preliminary results demonstrate progression of WM damage as evidenced by interval changes in diffusion anisotropy. Future research should examine the relationship between decreased FA and long-term clinical outcome.