Biomechanics of Spinal Cord Injury: A Multimodal Investigation Using Ex Vivo Guinea Pig Spinal Cord White Matter

2008 ◽  
Vol 25 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Hui Ouyang ◽  
Beth Galle ◽  
Jianming Li ◽  
Eric Nauman ◽  
Riyi Shi
2020 ◽  
Author(s):  
Beike Chen ◽  
Qiang Tan ◽  
Weikang Zhao ◽  
Qiming Yang ◽  
Hongyan Zhang ◽  
...  

Abstract Background: Diffusion tensor imaging (DTI) was an effective method to identify subtle changes to normal‐appearing white matter (WM). Here we analyzed the DTI data with other examinations, including motor evoked potentials (MEPs), histopathological images, and behavioral results, to reflect the lesion development in different degrees of spinal cord injury (SCI) in acute and subacute stage. Method: Except for 2 Sprague -Dawley rats died from anesthesia accident, the rest 42 female rats were randomized into 3 groups: control (n=6), moderate group (n=18), and severe group (n=18). Moderate (a 50-g aneurysm clip with 0.4-mm thickness spacer) or severe (a 50-g aneurysm clip with no spacer) contusion SCI at T8 vertebrae were induced. Then the electrophysiological assessments via MEPs, behavioral deterioration via the Basso, Beattie, and Bresnaha (BBB) scores, DTI data, and histopathology examination were analyzed. Results: In this study, we found that the damage of WM myelin, MEPs amplitude, BBB scores and the decreases in values of fractional anisotropy (FA) and axial diffusivity (AD) were more obvious in the severe injury group than that of the moderate group. Additionally, the FA and AD values could identify the extent of SCI in subacute and early acute SCI respectively, reflected in the robust correlations with MEPs and BBB scores. While the values of radial diffusivity (RD) showed no significant changes. Conclusions: Our data confirmed that DTI was a valuable in ex vivo imaging tool to identify damaged white matter tracts after graded SCI in rat, which may provide useful information for the early identification of the severity of SCI.


2007 ◽  
Vol 6 (3) ◽  
pp. 255-266 ◽  
Author(s):  
Anthony M. Choo ◽  
Jie Liu ◽  
Clarrie K. Lam ◽  
Marcel Dvorak ◽  
Wolfram Tetzlaff ◽  
...  

Object In experimental models of spinal cord injury (SCI) researchers have typically focused on contusion and transection injuries. Clinically, however, other injury mechanisms such as fracture–dislocation and distraction also frequently occur. The objective of the present study was to compare the primary damage in three clinically relevant animal models of SCI. Methods Contusion, fracture–dislocation, and flexion–distraction animal models of SCI were developed. To visualize traumatic increases in cellular membrane permeability, fluorescein–dextran was infused into the cerebrospi-nal fluid prior to injury. High-speed injuries (approaching 100 cm/second) were produced in the cervical spine of deeply anesthetized Sprague–Dawley rats (28 SCI and eight sham treated) with a novel multimechanism SCI test system. The animals were killed immediately thereafter so that the authors could characterize the primary injury in the gray and white matter. Sections stained with H & E showed that contusion and dislocation injuries resulted in similar central damage to the gray matter vasculature whereas no overt hemorrhage was detected following distraction. Contusion resulted in membrane disruption of neuronal somata and axons localized within 1 mm of the lesion epicenter. In contrast, membrane compromise in the dislocation and distraction models was observed to extend rostrally up to 5 mm, particularly in the ventral and lateral white matter tracts. Conclusions Given the pivotal nature of hemorrhagic necrosis and plasma membrane compromise in the initiation of downstream SCI pathomechanisms, the aforementioned differences suggest the presence of mechanism-specific injury regions, which may alter future clinical treatment paradigms.


2007 ◽  
Vol 58 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Joong Hee Kim ◽  
David N. Loy ◽  
Hsiao-Fang Liang ◽  
Kathryn Trinkaus ◽  
Robert E. Schmidt ◽  
...  

Author(s):  
Marie-Helene Beausejour ◽  
Eric Wagnac ◽  
Pierre-Jean Arnoux ◽  
Jean-Marc Mac-Thiong ◽  
Yvan Petit

Abstract Flexion-distraction injuries frequently cause traumatic cervical spinal cord injury (SCI). Post-traumatic instability can cause aggravation of the secondary SCI during patient's care. However, there is little information on how the pattern of disco-ligamentous injury affects the SCI severity and mechanism. This study objective was to analyze how different flexion-distraction disco-ligamentous injuries affect the SCI mechanisms during post-traumatic flexion and extension. A cervical spine finite element model including the spinal cord was used and different combinations of partial or complete intervertebral disc (IVD) rupture and disruption of various posterior ligaments were modeled at C4-C5, C5-C6 or C6-C7. In flexion, complete IVD rupture combined with posterior ligamentous complex rupture was the most severe injury leading to the most extreme von Mises stress (47 to 66 kPa), principal strains p1 (0.32 to 0.41 in white matter) and p3 (-0.78 to -0.96 in white matter) in the spinal cord and to the most important spinal cord compression (35 to 48 %). The main post-trauma SCI mechanism was identified as compression of the anterior white matter at the injured level combined with distraction of the posterior spinal cord during flexion. There was also a concentration of the maximum stresses in the gray matter after injury. Finally, in extension, the injuries tested had little impact on the spinal cord. The capsular ligament was the most important structure in protecting the spinal cord. Its status should be carefully examined during patient's management.


2018 ◽  
Vol 234 (2) ◽  
pp. 244-251 ◽  
Author(s):  
Azim Patar ◽  
Peter Dockery ◽  
Linda Howard ◽  
Siobhan S. McMahon

2021 ◽  
Author(s):  
Zheng Cao ◽  
Weitao Man ◽  
Yuhui Xiong ◽  
Yi Guo ◽  
Shuhui Yang ◽  
...  

Abstract A hierarchically aligned fibrin hydrogel (AFG) that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo. However, its potential in promoting nerve regeneration in large animal models that is critical for clinical translation has not been sufficiently specified. Here, the effects of AFG on directing neuroregeneration in canine hemisected T12 spinal cord injuries were explored. Histologically obvious white matter regeneration consisting of a large area of consecutive, compact, and aligned nerve fibers is induced by AFG, leading to a significant motor functional restoration. The canines with AFG implantation start to stand well with their defective legs from 3 to 4 weeks postoperatively and even effortlessly climb the steps from 7 to 8 weeks. Moreover, high-resolution multi-shot diffusion tensor imaging illustrates the spatiotemporal dynamics of nerve regeneration rapidly crossing the lesion within 4 weeks in the AFG group. Our findings indicate that AFG could be a potential therapeutic vehicle for spinal cord injury by inducing rapid white matter regeneration and restoring locomotion, pointing out its promising prospect in clinic practice.


2021 ◽  
Vol 16 (3) ◽  
pp. 550 ◽  
Author(s):  
HyunJoon Lee ◽  
RustemRobertovich Islamov ◽  
FilipOlegovich Fadeev ◽  
FaridVagizovich Bashirov ◽  
VaheArshaluysovich Markosyan ◽  
...  

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