Somatotopy of corticospinal tract in the internal capsule shown by functional MRI and diffusion tensor images

Abstract

Using functional MRI and diffusion tensor tractography, we studied the topographical relation of hand and foot fibers of the corticospinal tract within the internal capsule to verify the recent unexpected finding by Holodny et al., who reported that hand fibers are located anterolateral to foot fibers, not anteromedial as is currently believed. The location of hand fibers with respect to foot fibers was anterolateral in four participants, posterolateral in two, and anteromedial in one of seven participants examined. Thus, there was some support for the anterolateral finding of Holodny et al., but interindividual variability was also indicated.

Quantification of white matter fibre pathways disruption in frontal transcortical approach to the lateral ventricle or the interventricular foramen in diffusion tensor tractography

“…It arises from the motor cortex and travels through the corona radiata and posterior limb of internal capsule [26,42]. The current study have proven, that both trans-F1 and trans-F2 corridors violate only 1% of upper motor neuron axons, causing theoretically at most minor focal paresis of lower extremity.…”

Topographical Organization of the Pyramidal Fiber System - Diffusion Tensor MRI of the Human and Rhesus Monkey Brain

“…Conversely, tracking of hand and foot fibers in tumor patients indicated the fibers to be arranged along the left-right axis [11]. In another study, the observation of both topological orientations in a group of subjects was ascribed to interindividual differences in brain anatomy [13]. In fact, although DTI-based fiber tractography allows for a straightforward visualization of PT fibers in healthy humans and monkeys [15][16][17][18][19] as well as in patients with subcortical lesions [20], pertinent studies did not focus on the detailed topological organization of the PT as it passes through the semioval center and internal capsule into the brainstem.…”

“…Possible explanations for the uncertainties regarding the PT anatomy result from differences between humans and non-human primates as well as from the use of different experimental approaches ranging from whole brain dissections to lesion studies [4,[6][7][8][9] and, more recently, magnetic resonance diffusion tensor imaging (DTI) and virtual fiber tractography [10][11][12][13][14]. For example, tracking of pyramidal motor fibers in stroke patients revealed a somatotopic arrangement of the upper and lower extremities in anteriorposterior direction within the posterior limb of the internal capsule [12].…”

The Fate of Injured Corticospinal Tracts in Patients with Intracerebral Hemorrhage: Diffusion Tensor Imaging Study

“…Among patients with ICH who were admitted to the rehabilitation department of a university hospital, we recruited 45 consecutive patients (26 males, 19 females; mean age, 55.4 Ϯ 11.0 years; range, 4 -82 years) according to the following selection criteria: 1) first-ever stroke; 2) age 20 -85 years; 3) an ICH lesion at the level of the corona radiata or posterior limb of the internal capsule explaining the CST injury, [12][13][14][15][16][17] with confirmation by a neuroradiologist; 4) severe weakness of the affected extremities, to the extent of an inability to move without gravity at ICH onset; 5) the first DTI scanned within 30 days after onset and the second after 3 months from onset; 6) patient rehabilitation from the time of first DTI to the time of second DTI; and 7) absence of serious medical complications, such as pneumonia or cardiac problems, from onset to final evaluation. Patients who showed apraxia, somatosensory problems, severe spasticity (modified Ashworth scale Ͼ2), or severe cognitive problems (Mini-Mental State Examination Ͻ25) were excluded from this study.…”