Possible mechanisms for observed pathophysiological variability in experimental spinal cord injury by the method of Allen

1976 ◽  
Vol 44 (4) ◽  
pp. 429-434 ◽  
Author(s):  
Said H. Koozekanani ◽  
W. Michael Vise ◽  
Reza M. Hashemi ◽  
Robert B. McGhee
Keyword(s):  
Spinal Cord ◽  
High Speed ◽  
Spinal Cord Injuries ◽  
Cord Compression ◽  
High Speed Photography ◽  
Content Type ◽  
Drop Mass ◽  
Injury Model ◽  
Cord Injury ◽  
Animal Material

✓ Experimental spinal cord injuries were induced in dogs by dropping calibrated weights through a vented tube onto a small impounder resting on the surgically exposed cord. The motion of the impounder and the drop-mass were recorded by high-speed photography and the resulting data were compared to those obtained from a computer simulation of the dynamics of the injury mechanism. It is concluded that this method of inducing spinal cord injuries may yield markedly different degrees of cord compression depending upon the parameters of the animal material and apparatus even when the gm-cm of impact energy is maintained at a constant value. Some approaches to standardization of this injury model are suggested.

A reproducible spinal cord injury model in the cat

1983 ◽  
Vol 59 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Ronald W. J. Ford
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Cord Injuries ◽  
Sharp Transition ◽  
Content Type ◽  
Spinal Cord Injury Model ◽  
Injury Model ◽  
Cord Injury ◽  
Weight Drop ◽  
Future Evaluation

✓ Allen's weight-drop method for producing experimental spinal cord injuries was improved by placing a curved stainless steel plate anterior to the spinal cord to provide a smooth, hard surface for the receipt of posterior cord impact. In addition, an electronic circuit was used to ensure that cord injury was produced by a single impact, thereby enhancing the reproducibility of the injury mechanism. Using a spinal cord injury model with these modifications, the author found that the recovery of hindlimb function and the histopathological appearance of the injured cord 6 weeks after upper lumbar injury were closely related to injury magnitude. The curve of functional recovery versus injury magnitude has a sharp transition centered at 10 gm × 15 cm, and indicates that an injury of 10 gm × 20 cm produces a “threshold” lesion suitable for the future evaluation of spinal cord treatment methods.

Spinal cord concussion

1990 ◽  
Vol 72 (6) ◽  
pp. 894-900 ◽  
Author(s):  
Thomas J. Zwimpfer ◽  
Mark Bernstein
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Spinal Injury ◽  
Cord Compression ◽  
Neurological Deficits ◽  
Content Type ◽  
Young Males ◽  
Cord Injury ◽  
Sensory Disturbances ◽  
Fine Print

✓ The hallmark of concussion injuries of the nervous system is the rapid and complete resolution of neurological deficits. Cerebral concussion has been well studied, both clinically and experimentally. In comparison, spinal cord concussion (SCC) is poorly understood. The clinical and radiological features of 19 SCC injuries in the general population are presented. Spinal cord injuries were classified as concussions if they met three criteria: 1) spinal trauma immediately preceded the onset of neurological deficits; 2) neurological deficits were consistent with spinal cord involvement at the level of injury; and 3) complete neurological recovery occurred within 72 hours after injury. Most cases involved young males, injured during athletics or due to falls. Concussion occurred at the two most unstable spinal regions, 16 involving the cervical spinal and three the thoracolumbar junction. Fifteen cases presented with combined sensorimotor deficits, while four exhibited only sensory disturbances. Many patients showed signs of recovery with the first few hours after injury and most had completely recovered within 24 hours. Only one case involved an unstable spinal injury. There was no evidence of ligamentous instability, spinal stenosis, or canal encroachment in the remaining 18 cases. Two patients, both children, suffered recurrent SCC injuries. No delayed deterioration or permanent cord injuries occurred. Spinal abnormalities that would predispose the spinal cord to a compressive injury were present in only one of the 19 cases. This suggests that, as opposed to direct cord compression, SCC may be the result of an indirect cord injury. Possible mechanisms are discussed.

Value of gas myelography in early management of acute cervical spinal cord injuries

1975 ◽  
Vol 42 (3) ◽  
pp. 330-337 ◽  
Author(s):  
Alain B. Rossier ◽  
Jean Berney ◽  
Arthur E. Rosenbaum ◽  
Jurg Hachen
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Cord Compression ◽  
Cervical Cord ◽  
Valuable Contribution ◽  
Early Management ◽  
Specific Patient ◽  
Content Type ◽  
Cord Injury

✓ Gas myelography was carried out in 22 patients with acute cervical spinal cord injuries in whom oily contrast media seemed contraindicated. The authors believe this technique makes a valuable contribution to the basic decision regarding the surgical versus medical treatment of a specific patient with a cervical cord injury. They emphasize the importance of visualizing cord compression due to disc herniation in these cases and conclude that gases are the optimal contrast agents for visualization of the entire circumference of the spinal cord.

Therapeutic trial of hypercarbia and hypocarbia in acute experimental spinal cord injury

1984 ◽  
Vol 61 (5) ◽  
pp. 925-930 ◽  
Author(s):  
Ronald W. J. Ford ◽  
David N. Malm
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Cord Injuries ◽  
Mortality Rates ◽  
Therapeutic Trial ◽  
Tissue Preservation ◽  
Content Type ◽  
Experimental Spinal Cord Injury ◽  
Cord Injury ◽  
Fine Print

✓ Hypocarbia, normocarbia, or hypercarbia was maintained for an 8-hour period beginning 30 minutes after acute threshold spinal cord injuries in cats. No statistically significant differences in neurological recovery or histologically assessed tissue preservation were found among the three groups of animals 6 weeks after injury. No animal recovered the ability to walk. It is concluded that maintenance of hypercarbia or hypocarbia during the early postinjury period is no more therapeutic than maintenance of normocarbia. Mortality rates and tissue preservation data suggest, however, that postinjury hypocarbia may be less damaging than hypercarbia.

scholarly journals Improved rat spinal cord injury model using spinal cord compression by percutaneous method

2013 ◽  
Vol 14 (3) ◽  
pp. 329 ◽  
Author(s):  
Wook-Hun Chung ◽  
Jae-Hoon Lee ◽  
Dai-Jung Chung ◽  
Wo-Jong Yang ◽  
A-Jin Lee ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Cord Compression ◽  
Cord Compression ◽  
Rat Spinal Cord ◽  
Spinal Cord Injury Model ◽  
Injury Model ◽  
Cord Injury

The therapeutic window for spinal cord decompression in a rat spinal cord injury model

2005 ◽  
Vol 3 (4) ◽  
pp. 302-307 ◽  
Author(s):  
Christopher B. Shields ◽  
Y. Ping Zhang ◽  
Lisa B. E. Shields ◽  
Yingchun Han ◽  
Darlene A. Burke ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Stenosis ◽  
Spinal Cord Compression ◽  
Cord Compression ◽  
Therapeutic Window ◽  
Content Type ◽  
Significant Difference ◽  
Cord Injury ◽  
Fine Print

Object. There are no clinically based guidelines to direct the spine surgeon as to the proper timing to undertake decompression after spinal cord injury (SCI) in patients with concomitant stenosis-induced cord compression. The following three factors affect the prognosis: 1) severity of SCI; 2) degree of extrinsic spinal cord compression; and 3) duration of spinal cord compression. Methods. To elucidate further the relationship between varying degrees of spinal stenosis and a mild contusion-induced SCI (6.25 g-cm), a rat SCI/stenosis model was developed in which 1.13- and 1.24-mm-thick spacers were placed at T-10 to create 38 and 43% spinal stenosis, respectively. Spinal cord damage was observed after the stenosis—SCI that was directly proportional to the duration of spinal cord compression. The therapeutic window prior to decompression was 6 and 12 hours in the 43 and 38% stenosis—SCI lesions, respectively, to maintain locomotor activity. A significant difference in total lesion volume was observed between the 2-hour and the delayed time(s) to decompression (38% stenosis—SCI, 12 and 24 hours, p < 0.05; 43% stenosis—SCI, 24 hours, p < 0.05) indicating a more favorable neurological outcome when earlier decompression is undertaken. This finding was further supported by the animal's ability to support weight when decompression was performed by 6 or 12 hours compared with 24 hours after SCI. Conclusions. Analysis of the findings in this study suggests that early decompression in the rat improves locomotor function. Prolongation of the time to decompression may result in irreversible damage that prevents locomotor recovery.

Cerebrospinal fluid lactate and electrolyte levels following experimental spinal cord injury

1976 ◽  
Vol 44 (6) ◽  
pp. 715-722 ◽  
Author(s):  
Douglas K. Anderson ◽  
Leon D. Prockop ◽  
Eugene D. Means ◽  
Lawrence E. Hartley
Keyword(s):  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Spinal Cord Compression ◽  
Cord Compression ◽  
Spinal Cord Tissue ◽  
Post Injury ◽  
Content Type ◽  
Protein Levels ◽  
Cord Injury ◽  
Csf Lactate

✓ Cerebrospinal fluid (CSF) lactate, sodium (Na+), potassium (K+), calcium (Ca++), magnesium (Mg++), and chloride (Cl−) levels were determined for 17 to 21 days following experimental spinal cord compression in cats. Laminectomies were performed at L-2 under general anesthesia with aseptic techniques. Paraplegia was produced by applying a 170-gm weight transdurally for 5 minutes. Significant increases in CSF lactate levels were observed on the first through ninth days post injury with peak levels (50% above normal) occurring at Day 5. The only significant postinjury CSF electrolyte changes were elevation in Ca++ concentration on Days 3, 9, 11, 13, and 15, elevation in K+ concentration on Days 9 and 11 and decline in Cl− levels on the first day. The CSF K+ increase probably reflected cellular loss of K+ from damaged tissue whereas the Ca++ rise may have resulted from increased CSF protein levels. The prolonged elevation of CSF lactate indicates that tissue hypoxia plays a role in spinal cord compression paralysis, and that there is a continuing hypoxia of metabolically active spinal cord tissue for several days post injury.

Evolution of tissue damage in compressive spinal cord injury in rats

1987 ◽  
Vol 66 (4) ◽  
pp. 595-603 ◽  
Author(s):  
Hideaki Iizuka ◽  
Hirotaka Yamamoto ◽  
Yuzo Iwasaki ◽  
Teiji Yamamoto ◽  
Hidehiko Konno
Keyword(s):  
Spinal Cord ◽  
Tissue Damage ◽  
Spinal Cord Injuries ◽  
Sodium Dodecyl ◽  
Membrane Integrity ◽  
Secondary Degeneration ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Cord Injury ◽  
Mechanical Insult

✓ The evolution of tissue damage in compressive spinal cord injuries in rats was studied using an immunohistochemical technique and by sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) analysis. The rupture of small vessels accompanied by intense tissue permeation of serum components in and around the hemorrhagic foci appeared to be immediate consequences of the mechanical insult. The loss of cell membrane integrity in neural elements became evident within 1 hour after injury as shown by the diffuse albumin-immunoreactivity of the cytoplasm. At the site of mechanical insult, approximately 30% of the neurofilament proteins were degraded within 1 hour, and 70% of them were lost within 4 hours after injury. A large number of cells positive for glial fibrillary acidic protein were found to demarcate the injured tissue within 1 hour after injury. The progression of tissue damage largely subsided within 48 hours. One week after, injury, severe degeneration of the ascending tracts in the posterior funiculus was shown clearly by axon staining and less convincingly by myelin staining. Secondary degeneration of the corticospinal tract in distal segments remained inconspicuous for up to 3 months.

Effect of vasodilators and myelotomy on recovery after acute spinal cord injury in rats

1979 ◽  
Vol 50 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Alex S. Rivlin ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Quantitative Method ◽  
Cord Compression ◽  
Central Canal ◽  
Compression Injury ◽  
Dorsal Midline ◽  
Content Type ◽  
Cord Injury ◽  
Spinal Cord Function ◽  
Fine Print

✓ The effect of papaverine, nitroprusside, or myelotomy on the recovery of spinal cord function was studied in rats after acute cord-compression injury. Spinal cord recovery was measured by a quantitative method of clinical assessment previously developed in our laboratory. Neither papaverine nor nitroprusside improved recovery of cord function. Dorsal midline myelotomy extending anteriorly as far as the central canal did not produce significant improvement (p > 0.05). However, when the myelotomy extended completely through the cord in the anteroposterior plane significant improvement (p < 0.01) was obtained.

Pediatric spinal injury: the very young

1988 ◽  
Vol 68 (1) ◽  
pp. 25-30 ◽  
Author(s):  
John R. Ruge ◽  
Grant P. Sinson ◽  
David G. McLone ◽  
Leonard J. Cerullo
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Cord Injuries ◽  
Spinal Injury ◽  
Causative Factor ◽  
Important Variable ◽  
Neurological Injury ◽  
Content Type ◽  
Significant Difference ◽  
Cord Injury

✓ Maturity of the spine and spine-supporting structures is an important variable distinguishing spinal cord injuries in children from those in adults. Cinical data are presented from 71 children aged 12 years or younger who constituted 2.7% of 2598 spinal cord-injured patients admitted to the authors' institutions from June, 1972, to June, 1986. The 47 children with traumatic spinal cord injury averaged 6.9 years of age and included 20 girls (43%). The etiology of the pediatric injuries differed from that of adult injuries in that falls were the most common causative factor (38%) followed by automobile-related injuries (20%). Ten children (21.3%) had spinal cord injury without radiographic abnormality (SCIWORA), whereas 27 (57%) had evidence of neurological injury. Complete neurological injury was seen in 19% of all traumatic pediatric spinal cord injuries and in 40% of those with SCIWORA. The most frequent level of spinal injury was C-2 (27%, 15 cases) followed by T-10 (13%, seven cases). Upon statistical examination of the data, a subpopulation of children aged 3 years or younger emerged. These very young children had a significant difference in level of injury, requirement for surgical stability, and sex distribution compared to 4- to 12-year-old children.

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