Effect of aluminum on neurological recovery in rats following spinal cord injury

2000 ◽  
Vol 93 (2) ◽  
pp. 276-282 ◽  
Author(s):  
Khalaf Al Moutaery ◽  
Saleh Al Deeb ◽  
Nabil Biary ◽  
Christudas Morais ◽  
Haseeb Ahmad Khan ◽  
...  

Object. This investigation was undertaken to study the effect of aluminum on neurobehavioral, electrophysiological, structural, and biochemical changes in rats following spinal cord injury (SCI). Methods. Adult male Sprague—Dawley rats classified into different groups were given aluminum sulfate—dosed drinking water in the concentrations of 0%, 0.25%, 0.5% and 1%, respectively. After 30 days of aluminum treatment, the animals were subjected to spinal cord trauma. Laminectomy was performed at T7–8 in anesthetized rats, followed by placement of a compression plate (2.2 × 5 mm) loaded with a 35-g weight over the exposed spinal cord for 5 minutes. Control animals underwent the same surgical procedure, but the compression injury was not induced (sham). Postoperative neurological function was assessed using the inclined-plane test and by obtaining a modified Tarlov score and vocal/sensory score daily for 10 days. Electrophysiological changes were assessed using corticomotor evoked potentials, whereas pathological changes were assessed by light microscopy. The level of vitamin E in the spinal cord was measured as an index of antioxidant defense. The behavioral, biochemical, and histological analyses were performed in a blinded fashion. Conclusions. Analysis of results obtained in the behavioral studies revealed that the compression of spinal cord produced transient paraparesis in which a maximum motor deficit occurred at Day 1 following SCI and resolved over a period of 10 days. Administration of aluminum significantly impaired the recovery following SCI. Analysis of the results of the biochemical, electrophysiological, and histopathological studies also confirmed the deleterious effects of aluminum on recovery from SCI in rats.

1989 ◽  
Vol 71 (3) ◽  
pp. 403-416 ◽  
Author(s):  
Michael G. Fehlings ◽  
Charles H. Tator ◽  
R. Dean Linden

✓ There is evidence that posttraumatic ischemia is important in the pathogenesis of acute spinal cord injury (SCI). In the present study spinal cord blood flow (SCBF), measured by the hydrogen clearance technique, and motor and somatosensory evoked potentials (MEP and SSEP) were recorded to evaluate whether the administration of nimodipine and dextran 40, alone or in combination, could increase posttraumatic SCBF and improve axonal function in the cord after acute SCI. Thirty rats received a 53-gm clip compression injury on the cord at T-1 and were then randomly and blindly allocated to one of six treatment groups (five rats in each). Each group was given an intravenous infusion of one of the following over 1 hour, commencing 1 hour after SCI: placebo and saline; placebo and dextran 40; nimodipine 0.02 mg/kg and saline; nimodipine 0.02 mg/kg and dextran 40; nimodipine 0.05 mg/kg and saline; and nimodipine 0.05 mg/kg and dextran 40. The preinjury physiological parameters, including the SCBF at T-1 (mean ± standard error of the mean: 56.84 ± 4.51 ml/100 gm/min), were not significantly different (p > 0.05) among the treatment groups. Following SCI, there was a significant decrease in the SCBF at T-1 (24.55 ± 2.99 ml/100 gm/min; p < 0.0001) as well as significant changes in the MEP recorded from the spinal cord (MEP-C) (p < 0.0001), the MEP recorded from the sciatic nerve (MEP-N) (p < 0.0001), and the SSEP (p < 0.002). Only the combination of nimodipine 0.02 mg/kg and dextran 40 increased the SCBF at T-1 (43.69 ± 6.09 ml/100 gm/min; p < 0.003) and improved the MEP-C (p < 0.0001), MEP-N (p < 0.04), and SSEP (p < 0.002) following SCI. With this combination, the changes in SCBF were significantly related to improvement in axonal function in the motor tracts (p < 0.0001) and somatosensory tracts (p < 0.0001) of the cord. This study provides quantitative evidence that an increase in posttraumatic SCBF can significantly improve the function of injured spinal cord axons, and strongly implicates posttraumatic ischemia in the pathogenesis of acute SCI.


2004 ◽  
Vol 1 (3) ◽  
pp. 322-329 ◽  
Author(s):  
Ajay Bakshi ◽  
Omar Fisher ◽  
Taner Dagci ◽  
B. Timothy Himes ◽  
Itzhak Fischer ◽  
...  

Object. Spinal cord injury (SCI) is a complex pathological entity, the treatment of which requires a multipronged approach. One way to integrate different therapeutic strategies for SCI is to develop implantable scaffolds that can deliver therapies in a synergistic manner. Many investigators have developed implantable “bridges,” but an important property of such scaffolds—that is, mechanical compatibility with host tissues—has been neglected. In this study, the authors evaluated the results of implanting a mechanically matched hydrogel-based scaffold to treat SCI. Methods. A nonbiodegradable hydrogel, poly(2-hydroxyethylmethacrylate) (PHEMA), was engineered using thermally initiated free radical solution polymerization. Two groups of 12 adult Sprague—Dawley rats underwent partial cervical hemisection injury followed by implantation of either PHEMA or PHEMA soaked in 1 µg of brain-derived neurotrophic factor (BDNF). Four rats from each group were killed 1, 2, or 4 weeks after induction of the injury. Immunofluorescence staining was performed to determine the presence of scarring, cellular inflammatory responses, gliosis, angiogenesis, and axonal growth in and around the implanted scaffolds. Conclusions. The implanted PHEMA with 85% water content had a compressive modulus of 3 to 4 kPa, which matched the spinal cord. Implanted PHEMA elicited modest cellular inflammatory responses that disappeared by 4 weeks and minimal scarring was noted around the matrix. Considerable angiogenesis was observed in PHEMA, and PHEMA soaked in BDNF promoted axonal penetration into the gel. The authors conclude that mechanically engineered PHEMA is well accepted by host tissues and might be used as a platform for sustained drug delivery to promote axonal growth and functional recovery after SCI.


1985 ◽  
Vol 62 (5) ◽  
pp. 743-749 ◽  
Author(s):  
Masaki Kurihara

✓ A spinal cord injury was produced in Wistar rats by extradural compression of the cord with a Sugita aneurysm clip for 5 seconds. During a 2-week observation period following the injury, the tissue norepinephrine (NE), dopamine (DA), and serotonin (5-HT) concentrations decreased uniformly at and below the injured site. The chemical denervation of NE or 5-HT neurons produced by the intraspinal injection of 6-hydroxydopamine (6-OHDA) or 5,7-dihydroxytryptamine (5,7-DHT) 2 weeks before the injury did not cause a marked difference in the extent of hemorrhagic necrosis of the spinal cord after trauma as compared to control animals without pretreatment. In the rats pretreated with 6-OHDA, NE was decreased to less than 30% of control (non-pretreated) values, and, beginning at 5 days after injury, motor performance (assessed quantitatively with the inclined-plane method) was significantly improved compared to results in the non-pretreated control rats. The rats pretreated with 5,7-DHT showed no change from control animals. Spinal cord samples from non-pretreated control animals obtained at the injury site 30 minutes after the compression injury showed a marked decrease in the activity of synaptosomal Na+-K+-ATPase (adenosine triphosphatase) of about 50%, and an increase in both thiobarbituric acid reaction substance (about 170%) and cyclic guanine monophosphate (about 150%). The NE-denervated rats showed no significant changes in these three parameters. The results indicated that NE released after crush injury may impair the neuronal cell membrane around the lesion site by induction of lipid peroxidation. The possible mechanisms by which released NE may alter membrane function are discussed.


1994 ◽  
Vol 80 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Shlomo Constantini ◽  
Wise Young

✓ Recent clinical trials have reported that methylprednisolone sodium succinate (MP) or the monosialic ganglioside GM1 improves neurological recovery in human spinal cord injury. Because GM1 may have additive or synergistic effects when used with MP, the authors compared MP, GM1, and MP+GM1 treatments in a graded rat spinal cord contusion model. Spinal cord injury was caused by dropping a rod weighing 10 gm from a height of 1.25, 2.5, or 5.0 cm onto the rat spinal cord at T-10, which had been exposed via laminectomy. The lesion volumes were quantified from spinal cord Na and K shifts at 24 hours after injury and the results were verified histologically in separate experiments. A single dose of MP (30 mg/kg), given 5 minutes after injury, reduced 24-hour spinal cord lesion volumes by 56% (p = 0.0052), 28% (p = 0.0065), and 13% (p > 0.05) in the three injury-severity groups, respectively, compared to similarly injured control groups treated with vehicle only. Methylprednisolone also prevented injury-induced hyponatremia and increased body weight loss in the spine-injured rats. When used alone, GM1 (10 to 30 mg/kg) had little or no effect on any measured variable compared to vehicle controls; when given concomitantly with MP, GM1 blocked the neuroprotective effects of MP. At a dose of 3 mg/kg, GM1 partially prevented MP-induced reductions in lesion volumes, while 10 to 30 mg/kg of GM1 completely blocked these effects of MP. The effects of MP on injury-induced hyponatremia and body weight loss were also blocked by GM1. Thus, GM1 antagonized both central and peripheral effects of MP in spine-injured rats. Until this interaction is clarified, the authors recommend that MP and GM1 not be used concomitantly to treat acute human spinal cord injury. Because GM1 modulates protein kinase activity, protein kinases inhibit lipocortins, and lipocortins mediate anti-inflammatory effects of glucocorticoids, it is proposed that the neuroprotective effects of MP are partially due to anti-inflammatory effects and that GM1 antagonizes the effects of MP by inhibiting lipocortin. Possible beneficial effects of GM1 reported in central nervous system injury may be related to the effects on neural recovery rather than acute injury processes.


1984 ◽  
Vol 61 (5) ◽  
pp. 925-930 ◽  
Author(s):  
Ronald W. J. Ford ◽  
David N. Malm

✓ 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.


2002 ◽  
Vol 97 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Erkan Kaptanoglu ◽  
Selcuk Palaoglu ◽  
H. Selcuk Surucu ◽  
Mutlu Hayran ◽  
Etem Beskonakli

Object. There is a need for an accurate quantitative histological technique that also provides information on neurons, axons, vascular endothelium, and subcellular organelles after spinal cord injury (SCI). In this paper the authors describe an objective, quantifiable technique for determining the severity of SCI. The usefulness of ultrastructural scoring of acute SCI was assessed in a rat model of contusion injury. Methods. Spinal cords underwent acute contusion injury by using varying weights to produce graded SCI. Adult Wistar rats were divided into five groups. In the first group control animals underwent laminectomy only, after which nontraumatized spinal cord samples were obtained 8 hours postsurgery. The weight-drop technique was used to produce 10-, 25-, 50-, and 100-g/cm injuries. Spinal cord samples were also obtained in the different trauma groups 8 hours after injury. Behavioral assessment and ultrastructural evaluation were performed in all groups. When the intensity of the traumatic injury was increased, behavioral responses showed a decreasing trend. A similar significant negative correlation was observed between trauma-related intensity and ultrastructural scores. Conclusions. In the present study the authors characterize quantitative ultrastructural scoring of SCI in the acute, early postinjury period. Analysis of these results suggests that this method is useful in evaluating the degree of trauma and the effectiveness of pharmacotherapy in neuroprotection studies.


2005 ◽  
Vol 3 (4) ◽  
pp. 302-307 ◽  
Author(s):  
Christopher B. Shields ◽  
Y. Ping Zhang ◽  
Lisa B. E. Shields ◽  
Yingchun Han ◽  
Darlene A. Burke ◽  
...  

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.


1986 ◽  
Vol 65 (1) ◽  
pp. 108-110 ◽  
Author(s):  
Daniel Dumitru ◽  
James E. Lang

✓ A rare case of cruciate paralysis is reported in a 39-year-old man following a motor-vehicle accident. The differentiation of this syndrome from a central cervical spinal cord injury is delineated.


2004 ◽  
Vol 100 (1) ◽  
pp. 56-61
Author(s):  
Pierre-Yves Mure ◽  
Mark Galdo ◽  
Nathalie Compagnone

Object. The authors conducted a study to establish outcomes associated with bladder function in a mouse model of spinal cord injury (SCI) and to assess the sensitivity of these outcomes in determining the efficacy of pharmacological treatments. Methods. A mouse model of moderate contusive SCI was used. Outcome parameters included physiological, behavioral, and morphological measurements. To test the sensitivity of these outcomes, the authors used a dehydroepiandrosterone (DHEA) treatment that they had previously shown to promote neurological recovery effectively after SCI. A behavioral scale was used to identify the day at which autonomic function of the bladder was recovered. The reduction in the daily volume of urine during the period of functional recovery paralleled this scale. They then determined the day postinjury at which the functional differences between the vehicle- and DHEA-treated mice exhibited the maximal amplitude. Changes were measured in the composition of the extracellular matrix relative to collagen expression in the layer muscularis of the detrusor at this time point. They found that SCI increases the ratio of collagen type III to collagen type I in the detrusor. Moreover, in the DHEA-treated group, this ratio was similar to that demonstrated in sham-operated mice, establishing the sensitivity of this outcome to assess therapeutic benefits to the bladder function. They next examined the relationship between measurements of neurological recovery and controlled voiding by using cluster analysis. Conclusions. The authors found that early recovery of controlled voiding is predictive of motor recovery.


1985 ◽  
Vol 62 (4) ◽  
pp. 558-562 ◽  
Author(s):  
Giancarlo Barolat-Romana ◽  
Joel B. Myklebust ◽  
David C. Hemmy ◽  
Barbara Myklebust ◽  
William Wenninger

✓ Six patients with intractable spasms after spinal cord injury underwent implantation of an epidural spinal cord stimulation system. All the patients experienced good relief postoperatively. In three patients spinal cord stimulation consistently produced immediate inhibition of the spasms. This was evident within less than 1 minute of stimulation. Conversely, the spasms reappeared within less than 1 minute after cessation of the stimulation. The clinical observations were confirmed by polygraphic electromyographic recordings.


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