scholarly journals Longitudinal changes in DTI parameters of specific spinal white matter tracts correlate with behavior following spinal cord injury in monkeys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Arabinda Mishra ◽  
Feng Wang ◽  
Li Min Chen ◽  
John C. Gore
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Spinal Cord Injuries ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Human Subjects ◽  
Realistic Model ◽  
White Matter Tracts ◽  
Injured Side ◽  
Cord Injury

Abstract This study aims to evaluate how parameters derived from diffusion tensor imaging reflect axonal disruption and demyelination in specific white matter tracts within the spinal cord of squirrel monkeys following traumatic injuries, and their relationships to function and behavior. After a unilateral section of the dorsal white matter tract of the cervical spinal cord, we found that both lesioned dorsal and intact lateral tracts on the lesion side exhibited prominent disruptions in fiber orientation, integrity and myelination. The degrees of pathological changes were significantly more severe in segments below the lesion than above. The lateral tract on the opposite (non-injured) side was minimally affected by the injury. Over time, RD, FA, and AD values of the dorsal and lateral tracts on the injured side closely tracked measurements of the behavioral recovery. This unilateral section of the dorsal spinal tract provides a realistic model in which axonal disruption and demyelination occur together in the cord. Our data show that specific tract and segmental FA and RD values are sensitive to the effects of injury and reflect specific behavioral changes, indicating their potential as relevant indicators of recovery or for assessing treatment outcomes. These observations have translational value for guiding future studies of human subjects with spinal cord injuries.

scholarly journals White matter regeneration induced by aligned fibrin nanofiber hydrogel contributes to motor functional recovery in canine T12 spinal cord injury

2021 ◽  
Author(s):  
Zheng Cao ◽  
Weitao Man ◽  
Yuhui Xiong ◽  
Yi Guo ◽  
Shuhui Yang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Nerve Regeneration ◽  
Spinal Cord Injuries ◽  
Diffusion Tensor ◽  
Nerve Fibers ◽  
Functional Restoration ◽  
Large Animal ◽  
Cord Injury

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.

scholarly journals Segmented quantitative diffusion tensor imaging evaluation of acute traumatic cervical spinal cord injury

2020 ◽  
pp. 20201000
Author(s):  
Mahmud Mossa-Basha ◽  
Daniel J Peterson ◽  
Daniel S Hippe ◽  
Justin E Vranic ◽  
Christoph Hofstetter ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury ◽  
Motor Tracts ◽  
Normal Controls

Objectives: To evaluate segmented diffusion tensor imaging (DTI) white matter tract fractional anisotropy (FA) and mean diffusivity (MD) values in acute cervical spinal cord injury (CSCI). Methods: 15 patients with acute CSCI and 12 control subjects were prospectively recruited and underwent axial DTI as part of the spine trauma MRI. Datasets were put through a semi-automated probabilistic segmentation algorithm that analyzed white matter, motor and sensory tracts. FA and MD values were calculated for white matter, sensory (spinal lemniscal) and motor tracts (ventral/lateral corticospinal) at the level of clinical injury, levels remote from injury and in normal controls. Results: There were significant differences in FA between the level of injury and controls for total white matter (0.65 ± .09 vs 0.68 ± .07; p = .044), motor tracts (0.64 ± .07 vs 0.7 ± .09; p = .006), and combined motor/sensory tracts (0.63 ± .09 vs 0.69 ± .08; p = .022). In addition, there were significant FA differences between the level of injury and one level caudal to the injury for combined motor tracts (0.64 ± .07 vs 0.69 ± .05; p = .002) and combined motor/sensory tracts (0.63 ± .09 vs 0.7 ± .07; p = .011). There were no significant differences for MD between the level of injury and one level caudal to the injury or normal controls. Conclusion: Abnormalities in DTI metrics of DTI-segmented white matter tracts were detected at the neurological level of injury relative to normal controls and levels remote from the injury site, confirming its value in CSCI assessment. Advances in knowledge: Segmented DTI analysis can help identify microstructural spinal cord abnormalities in the setting of traumatic cervical spinal cord injury.

scholarly journals Noninvasive diffusion tensor imaging of evolving white matter pathology in a mouse model of acute spinal cord injury

2007 ◽  
Vol 58 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Joong Hee Kim ◽  
David N. Loy ◽  
Hsiao-Fang Liang ◽  
Kathryn Trinkaus ◽  
Robert E. Schmidt ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Mouse Model ◽  
Diffusion Tensor ◽  
Acute Spinal Cord Injury ◽  
Cord Injury ◽  
White Matter Pathology

Numerical Investigation of Spinal Cord Injury After Flexion-Distraction Injuries At the Cervical Spine

2021 ◽  
Author(s):  
Marie-Helene Beausejour ◽  
Eric Wagnac ◽  
Pierre-Jean Arnoux ◽  
Jean-Marc Mac-Thiong ◽  
Yvan Petit
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spine ◽  
White Matter ◽  
Cervical Spinal Cord ◽  
Element Model ◽  
Von Mises Stress ◽  
Study Objective ◽  
Cord Injury ◽  
Post Traumatic

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.

scholarly journals Important Role of Reverse Na+-Ca2+Exchange in Spinal Cord White Matter Injury at Physiological Temperature

2000 ◽  
Vol 84 (2) ◽  
pp. 1116-1119 ◽  
Author(s):  
Shuxin Li ◽  
Qiubo Jiang ◽  
Peter K. Stys
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Traumatic Injury ◽  
White Matter Injury ◽  
Mechanical Trauma ◽  
White Matter Tracts ◽  
Physiological Temperature ◽  
Cord Injury ◽  
Cellular Ca

Spinal cord injury is a devastating condition in which most of the clinical disability results from dysfunction of white matter tracts. Excessive cellular Ca2+ accumulation is a common phenomenon after anoxia/ischemia or mechanical trauma to white matter, leading to irreversible injury because of overactivation of multiple Ca2+-dependent biochemical pathways. In the present study, we examined the role of Na+-Ca2+ exchange, a ubiquitous Ca2+ transport mechanism, in anoxic and traumatic injury to rat spinal dorsal columns in vitro. Excised tissue was maintained in a recording chamber at 37°C and injured by exposure to an anoxic atmosphere for 60 min or locally compressed with a force of 2 g for 15 s. Mean compound action potential amplitude recovered to ≈25% of control after anoxia and to ≈30% after trauma. Inhibitors of Na+-Ca2+ exchange (50 μM bepridil or 10 μM KB-R7943) improved functional recovery to ≈60% after anoxia and ≈70% after traumatic compression. These inhibitors also prevented the increase in calpain-mediated spectrin breakdown products induced by anoxia. We conclude that, at physiological temperature, reverse Na+-Ca2+exchange plays an important role in cellular Ca2+ overload and irreversible damage after anoxic and traumatic injury to dorsal column white matter tracts.

scholarly journals Reduced FOV diffusion tensor MR imaging and fiber tractography of pediatric cervical spinal cord injury

Spinal Cord ◽  
2016 ◽  
Vol 55 (3) ◽  
pp. 314-320 ◽  
Author(s):  
M Alizadeh ◽  
A Intintolo ◽  
D M Middleton ◽  
C J Conklin ◽  
S H Faro ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Mr Imaging ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Fiber Tractography ◽  
Cord Injury ◽  
Diffusion Tensor Mr Imaging

Recurrent Asystole Resulting from High Cervical Spinal Cord Injuries

2006 ◽  
Vol 72 (6) ◽  
pp. 525-529 ◽  
Author(s):  
D.L. Franga ◽  
M.L. Hawkins ◽  
R.S. Medeiros ◽  
D. Adewumi
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Cardiac Pacemakers ◽  
Cord Injury ◽  
Pacemaker Placement ◽  
Level I ◽  
High Cervical ◽  
Short Time ◽  
Injured Patients

Cervical spinal cord injury is a highly morbid condition frequently associated with cardiovascular instability. This instability may include bradyarrhythmias, as well as hypotension, and usually resolves in a relatively short time. However, over a 3-year period (January 2003–December, 2005), 5 of 30 patients with complete cervical spinal cord injuries seen at our Level I trauma center required placement of permanent cardiac pacemakers for recurrent bradycardia/asystolic events. Strong consideration for pacemaker placement should be given for those spinal cord-injured patients with symptomatic bradyarrhythmic events still occurring 2 weeks after injury.

Identification of Severities of Spinal Cord Injury during Acute Phase in Rats by Diffusion Tensor Imaging

2020 ◽  
Author(s):  
Beike Chen ◽  
Qiang Tan ◽  
Weikang Zhao ◽  
Qiming Yang ◽  
Hongyan Zhang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Motor Evoked Potentials ◽  
Ex Vivo ◽  
Female Rats ◽  
Aneurysm Clip ◽  
Cord Injury

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.

Sign in / Sign up

Export Citation Format

Share Document