2026-10-06T08:56:08Z https://api.figshare.com/v2/oai

oai:figshare.com:article/28677545 2026-10-02T22:54:26Z category_31208 category_33752 portal_693 item_type_3 month_year_10_2026

Contralesional motor pathway enhancement after stroke: multimodal insights into lower limb function Brice Cleland (10613513) Biomedical and clinical sciences Health sciences stroke fMRI diffusion weighted MRI lower limb neural pathways <p dir="ltr"><b>Introduction:</b> We used complementary measures of motor pathway organization to determine whether relative contralesional pathway enhancement is associated with lower-limb function and whether this relationship depends on damage to the ipsilesional corticospinal tract (CST). <b>Methods:</b> In individuals with chronic stroke, we measured: 1) transcranial magnetic stimulation (TMS) corticomotor excitability; 2) functional magnetic resonance imaging (fMRI) brain activation; and 3) diffusion tensor imaging (DTI) fractional anisotropy in the corticospinal tracts. Relative excitability, functional activation, and structural integrity between hemispheres was calculated, and a single composite index of hemisphere predominance was developed. We tested associations with motor impairment, walking speed and endurance, and interlimb coordination, and whether these associations varied with ipsilesional CST lesion load. <b>Results:</b> 33 individuals with chronic stroke [60.7 (8.3) years old; 24 male; 8.6 (6.6) years post-stroke] were enrolled. Overall, greater ipsilesional predominance was associated with less motor impairment (<i>r</i>^<em>2</em>=0.25, <i>p</i>=0.006) and better interlimb coordination (<i>r</i>^<em>2</em>=0.17, <i>p</i>=0.03), but individuals with lower lesion load had better lower limb function motor impairment interaction, <i>p</i>=0.004; interlimb coordination interaction, <i>p</i>=0.007) when ipsilesional pathways were predominant, whereas those with higher lesion load had better lower limb function when contralesional pathways were predominant. <b>Conclusions:</b> The functional relevance of contralesional motor pathway involvement after stroke depends on the integrity of the ipsilesional CST. Contralesional predominance may be less favorable when ipsilesional pathways are relatively preserved but potentially compensatory when CST damage is more extensive. These findings support individualized approaches to interpreting post-stroke motor reorganization that account for residual CST integrity.</p> 2026-10-02T22:54:26Z Dataset Dataset 10.25417/uic.28677545.v1 https://figshare.com/articles/dataset/Contralesional_motor_pathway_enhancement_after_stroke_multimodal_insights_into_lower_limb_function/28677545 In Copyright