Somatotopically located motor fibers in corona radiata: Evidence from subcortical small infarcts

Using T2-weighted MRI, we measured the relative anteroposterior distance of small corona radiata infarcts in 54 patients who had disproportionate weakness in the bulbar ( Group A), arm ( Group B), and leg ( Group C) muscles. The lesions were differently ( p < 0.01) located: Group A, most were located anteriorly; Group B, most were in the middle; and Group C, most were located posteriorly. These results suggest that motor fibers are somatotopically arranged in the human corona radiata.