DAÑO AXONAL DIFUSO SECUNDARIO A TRAUMATISMO CRANEOENCEFÁLICO Neurología del paciente en situación critica ( Neurocríticos).
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Log in Sign up. Immediate disconnection of axons could be observed in severe brain injury, but the major damage of DAI is delayed secondary axon disconnections slowly developed over an extended time course.
Case qxonal Case 5. In Grade I, widespread axonal damage is present but no focal abnormalities are seen. Misalignment of cytoskeletal elements after stretch injury can lead to tearing of the axon and death of the neuron.
Diffuse axonal injury | Radiology Reference Article |
Some lesions may be difisa non-hemorrhagic even using high field strength SWI sequences. Non-contrast CT of the brain is routine in patients presenting with head lesioon. Case 4 Case 4. Textbook Of Traumatic Brain Injury. As such the diagnosis is often not suspected until later when patients fail to recover neurologically as expected. DAI is the result of traumatic shearing forces that occur when the head is rapidly accelerated or decelerated, as may occur in car accidents, falls, and assaults.
As such, it is usually a safe assumption that if a couple of small hemorrhagic lesions are visible on CT, the degree of damage is much greater.
Diffuse axonal injury
The amount of axonal injury in the brainstem is predictive of long-term vegetative aonal, whereas supratentorial injury can result in focal neurological or neuropsychiatric deficits 1.
Retrieved 18 July The patients at risk of diffuse axonal injury belong to the same cohort as those who suffer traumatic brain injury and as such young men are very much over-represented.
Thus injury is frequently more severe than is realized, and medical professionals should suspect DAI in any patients whose CT scans appear normal but who have symptoms like unconsciousness. They typically become more evident over the first few days as edema develops around them.
Journal of Clinical Difussa. The Journal of Neuroscience. Importantly, it should be noted, that even with high field strength modern scanners, the absence of findings does not categorically exclude the presence of axonal injury.
When the axon is transected, Wallerian degenerationin which the part of the axon distal to the break degrades, takes place within one to two days after injury. DAI can occur across the spectrum of traumatic brain injury TBI severity, wherein the burden axinal injury increases from mild to severe.
In Grade II, damage found in Grade I is present in addition to focal abnormalities, especially in the corpus callosum. Besides mechanical breaking of the axonal cytoskeleton, DAI pathology also includes secondary physiological changes such as interrupted axonal transport, progressive swellings and degeneration. Howard University College of Medicine. Over the first few days, the degree of surrounding edema will typically increase, although by 3-months post-injury FLAIR changes will have largely resolved 7.
Susceptibility weighted image SWI of diffuse axonal injury in trauma at 1. In other projects Wikimedia Commons. Support Radiopaedia and see fewer ads.
Neuroimaging Clinics of Axonap America. This is to be expected as edema is faster to resolve than hemorrhage. In contrast, SWI changes will usually take longer to resolve, although by months post-injury there will have been substantial resolution 7. Unfortunately, it is not sensitive to subtle diffuse axonal injury and as such, some patients with relatively normal CT scans may have significant unexplained neurological deficit Nerve injury Peripheral nerve injury classification Wallerian degeneration Injury of accessory nerve Brachial plexus injury Traumatic neuroma.
Traumatic axonal injury induces calcium influx modulated by tetrodotoxin-sensitive sodium channels.
Evidence for enduring changes in axolemmal permeability with associated cytoskeletal change. Axons are normally elastic, but when rapidly stretched they become brittle, and the axonal cytoskeleton can be broken. Neurotrauma S06, Sx4, T DAI is classified into grades based on severity of the injury. Retrieved 8 October Journal of Neuropathology and Experimental Neurology. Diffuse injury has more microscopic injury than macroscopic injury and is difficult to detect with CT and MRI, but its presence can be inferred when small bleeds are visible in the corpus callosum or the cerebral cortex.
Axoplasmic transport and neuronal responses to injury Archived at the Wayback Machine.
Lseion Wikipedia, the free encyclopedia. DAI is difficult to detect since it does not show up well on CT scans or with other macroscopic imaging techniques, though it shows up microscopically. Diffuse axonal injury is characterised by multiple focal lesions with a characteristic distribution: Management and staging of traumatic brain injury.
In the majority of cases, these forces result in damage to the cells and result in edema. About Blog Go ad-free.
Diffuse axonal injury – Wikipedia
Mechanism of calcium entry during axon injury and degeneration. Central Nervous SystemTrauma. When lesions are hemorrhagic, and especially when they are large, then CT is quite sensitive. Non-hemorrhagic ldsion are hypodense.