Axon diameter and intra-axonal volume fraction of the corticospinal tract
in idiopathic normal pressure hydrocephalus measured by Q-Space imaging.
WD is the process of progressive demyelination and disintegration of the distal axonal segment following transection of the axon or damage to the neuron. It was first discovered and named by Waller in experiments involving frogs in 1850. Compared with other fiber systems, it is typically observed to affect the corticospinal tracts
after an injury to the motor cortex or the internal capsule. Although poststroke WD is also a secondary neurodegenerative disorder, WD of the bilateral MCPs following pons infarction is a relatively rare phenomenon.
In turn, this could lead to decreased activity of the striatum, which inhibits the inhibitory output from the BG network to the thalamus modulating the activity of the corticospinal tract
It is considered that a damaged central nervous system will never be restored , but we reported that the once paralyzed motor function of the forelimbs of juvenile rats had been restored due to a significant change that occurred in the corticospinal tract
pathways after a brain injury .
Li, "Functional repair of the corticospinal tract
by delayed transplantation of olfactory ensheathing cells in adult rats," Journal of Neuroscience, vol.
* white matter tracts: corticospinal tract
, reticulospinal tracts and afferent tracts, e.g.
In humans, the corticospinal tract
extends from the cerebral cortex in the upper brain down into the spinal cord.
Intraoperative neurophysiological monitoring of the spinal cord during spinal cord and spine surgery: a review focus on the corticospinal tracts
. Clin Neurophysiol.
Brain MRI revealed increased signal intensity on T2 in the "corona radiate" extending into the "corticospinal tracts
." There was an initial impression of ALS.
Neuropathologic examination of FSP reveals axonal degeneration in the terminal portions of the spinal cord affecting corticospinal tracts
and dorsal column fibers with little involvement of the spinocerebellar tracts.
His MRI Brain done on Day 3 of admission revealed the following interesting finding: Hyperintense signal change in pons with partial sparing of the tegmentum, ventrolateral pons and corticospinal tracts
on FLAIR (Fig.
This is in contrast to the pyramidal corticospinal tracts
that control volitional movement and are predominantly crossed (approximately 90% of the corticospinal tract
fibers that originate from one hemisphere innervate the contralateral upper and lower extremities) .