Article

This study investigated white matter alterations in the corpus
callosum (CC) and centrum semiovale (CSO), using diffusion tensor imaging and
magnetization transfer imaging, in participants with severe traumatic brain
injury (TBI) and related these changes to processing speed measures. METHODS: Fourteen adult participants with severe TBI underwent neuroimaging
and assessment, using the Symbol Digit Modalities Test and Trail-Making Test,
Part B, at approximately 6 months postinjury. Thirteen demographically similar,
neurologically intact adults were imaged for comparison. RESULTS: The TBI group
demonstrated lower fractional anisotropy (FA) for the right CSO and higher
apparent diffusion coefficient (ADC) for the CSO bilaterally than the control
group. Lower FA and higher ADC were noted in all CC regions. Magnetization
transfer imaging revealed smaller magnetization transfer ratios (MTRs) in the
right and left CSO and CC genu and splenium. Written Symbol Digit Modalities Test
performance was related to right CSO FA, bilateral CSO ADC, CC FA, and right CSO
MTR, whereas oral Symbol Digit Modalities Test was related to right CSO FA, ADC,
and MTR. Trail-Making Test, Part B, was related to right CSO FA and MTR.
CONCLUSIONS: Advanced neuroimaging modalities such as diffusion tensor imaging
and magnetization transfer imaging demonstrate significant alterations in white
matter, which are related to processing speed. These techniques may be useful in
quantifying the extent of injury even in normal appearing white matter after TBI.

Langue : ANGLAIS