Clinicotopographical correlation of corticospinal tract stroke: a color-coded diffusion tensor imaging study.

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Small lacunar strokes affecting the pyramidal tract are challenging to precisely locate and assess for damage using conventional brain imaging.
• Color-coded diffusion tensor imaging (CDTI) offers a method to visualize the corticospinal tract's course within white matter.
• This study analyzed topographical patterns of small lacunar corticospinal tract strokes using diffusion-weighted MRI and CDTI.

Purpose of the Study:

• To investigate the utility of CDTI in characterizing subcortical strokes.
• To correlate lesion patterns identified by CDTI with clinical presentation and prognosis.
• To differentiate distinct subtypes of subcortical strokes based on imaging findings.

Main Methods:

• Examined 15 patients with subacute pyramidal tract strokes (days 3-7).
• Utilized diffusion-weighted MRI to identify lesions, superimposed on CDTI images for anatomical localization.
• Assessed lesion patterns, compared with clinical presentation, and evaluated quantitative parameters like mean diffusivity and lattice anisotropy.

Main Results:

• Identified 5 distinct corticospinal tract stroke patterns, categorized into two clinical subgroups: marked deficits with minor improvement (6/15) and good recovery (9/15).
• Group 1 lesions were long, centered in the pyramidal tract, and involved the basal ganglia.
• Group 2 lesions were small and/or located anteriorly/medially in the periventricular anterior choroidal artery territory or its branches. Lesions demonstrated increased mean diffusivity and decreased lattice anisotropy.

Conclusions:

• CDTI enables in vivo differentiation of various subcortical stroke subtypes.
• Enhanced anatomical definition of lesion localization via CDTI can improve prognostic accuracy for patients with subcortical stroke.