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Animal Studies in Spinal Cord Injury: A Systematic Review of Methylprednisolone
Abstract
The objective of this study was to examine whether animal studies can reliably be used to determine the usefulness of methylprednisolone (MP) and other treatments for acute spinal cord injury (SCI) in humans. This was achieved by performing a systematic review of animal studies on the effects of MP administration on the functional outcome of acute SCI. Data were extracted from the published articles relating to: outcome; MP dosing regimen; species/strain; number of animals; methodological quality; type of injury induction; use of anaesthesia; functional scale used; and duration of follow-up. Subgroup analyses were performed, based on species or strain, injury method, MP dosing regimen, functional outcome measured, and methodological quality. Sixty-two studies were included, which involved a wide variety of animal species and strains. Overall, beneficial effects of MP administration were obtained in 34% of the studies, no effects in 58%, and mixed results in 8%. The results were inconsistent both among and within species, even when attempts were made to detect any patterns in the results through subgroup analyses. The results of this study demonstrate the barriers to the accurate prediction from animal studies of the effectiveness of MP in the treatment of acute SCI in humans. This underscores the need for the development and implementation of validated testing methods.
... These studies were refuted on the basis of the research design, data collection and statistical analysis. Akhtar et al [19] performed a systematic review of animal studies addressing the effects of methylprednisolone administration on the functional outcome of acute spinal cord injury. Sixty-two studies were included, which involved a wide variety of animal species and strains. ...
... The results of this study demonstrated the barriers to the accurate prediction from animal studies of the effectiveness of methylprednisolone in the treatment of acute spinal cord injury in humans. In addition, a large number of level I evidence studies [19][20][21][22][23] revealed that methylprednisolone use has many side effects and the treatment effectiveness is unclear. Therefore, there is insufficient evidence to support the use of high-dose methylprednisolone as a standard treatment in acute spinal cord injury. ...
... The relative contraindications are a history of gastrointestinal ulcer or bleeding, existing heart disease, and severe infection. (19) The time window (< 8 hours) and correct infusion speed should be strictly controlled when using high-dose methylprednisolone, with accurate measurement of body weight and dose. Great attention should be paid to preventing gastrointestinal bleeding and infection, and to controlling blood sugar levels. ...
This is an expert consensus on the evaluation and treatment of thoracolumbar spinal injury, established from February 2009 to July 2010. The expert consensus consists mainly of six parts with a total of 54 recommendations including the overview (one item); pre-hospital care (one item); evaluation and diagnosis (13 items); treatment (23 items); prevention and treatment of major complications (12 items); and rehabilitation (four items). This is the first time that Chinese experts have published a consensus on spine and spinal cord injury. The expert consensus was established based on Delphi methods, literature analysis, and clinical experiences. Each recommendation is supported by and was interpreted using multi-level evidences. The level of agreement with the recommendation among the panel members was assessed as either low, moderate, or strong. Each panel member was asked to indicate his or her level of agreement on a 5-point scale, with "1" corresponding to neutrality and "5" representing maximum agreement. Scores were aggregated across the panel members and an arithmetic mean was calculated. This mean score was then translated into low, moderate, or strong. After all of the votes were collected and calculated, the results showed no low-level recommendations, 10 moderate-level recommendations, and 44 strong-level recommendations. An expert consensus was reached and was recognized by Chinese spine surgeons. Wide-scale adoption of these recommendations is urgent in the management of acute thoracolumbar spine and spinal cord injury in a broader attempt to create a standard evaluation and treatment strategy for acute thoracolumbar spine and spinal cord injury in China.
... Historically, there are two main types of degenerative disc diseases [6,7,9]. Hansen-I or extrusion of intervertebral discs occurs which is usually seen in chondrodystrophic dog breeds and involves the extrusion of the nucleus pulposus through all layers of the degenerated annulus fibrosus into the spinal canal [6,9,14]. Hansen-II type or protrusion of the intervertebral disc is mainly found in nonchondrodystrophic dogs of medium and large breed [13,14,15]. ...
... Hansen-I or extrusion of intervertebral discs occurs which is usually seen in chondrodystrophic dog breeds and involves the extrusion of the nucleus pulposus through all layers of the degenerated annulus fibrosus into the spinal canal [6,9,14]. Hansen-II type or protrusion of the intervertebral disc is mainly found in nonchondrodystrophic dogs of medium and large breed [13,14,15]. The weakened hypertrophied annulus is displaced dorsally into the spinal canal, resulting in chronic progressive spinal cord compression. ...
... Due to its strong anti-inflammatory effect, MPS has a long history of use in a wide range of diseases. However, many animal studies demonstrate controversial results regarding the neuroprotective efficacy of MPS (Akhtar et al. 2009). Like other glucocorticoids, MPS is characterized by adverse side effects which depend on both the dose and the duration of administration and can vary from bodily changes (for example, swelling) to the effects that threaten the patient's life. ...
... Relatively slow progression of secondary damage, which can take from several hours to several days after the initial damage, provides a therapeutic window and lays the foundation for the development of modern clinical protocols for systemic administration of MPS after SCI. MPS was originally found to exhibit protective effect against secondary damage in animal models (Akhtar et al. 2009). To date, MPS is widely used to minimize secondary damage by reducing inflammatory response after SCI and the level of free radicals that cause lipid peroxidation (Zhang et al. 2013). ...
Localized carrier-mediated administration of drugs is a promising approach to treatment of acute phase of spinal cord injury (SCI) as it allows enhanced and/or sustained drug delivery to damaged tissues along with minimization of systemic side effects. We studied the effect of locally applied self-assembling micellar formulation of methylprednisolone succinate (MPS) with trifunctional block copolymer of ethylene oxide and propylene oxide (TBC) on functional recovery and tissue drug content after SCI in rats in comparison with local and systemic administration of MPS alone. Variations in the amplitude of motor evoked responses in the hindlimb muscles induced by epidural stimulation during acute phase of SCI and restoration of movements during chronic period after local vs. systemic application of MPS were evaluated in this study. Results demonstrate that local delivery of MPS in combination with TBC facilitates spinal cord sensorimotor circuitry, increasing the excitability. In addition, this formulation was found to be more effective in improvement of locomotion after SCI compared to systemic administration. LC–MS/MS data shows that the use of TBC carrier increases the glucocorticoid content in treated spinal cord by more than four times over other modes of treatment. The results of this study demonstrate that the local treatment of acute SCI with MPS in the form of mixed micelles with TBC can provide improved therapeutic outcome by promoting drug accumulation and functional restoration of the spinal cord.
... Informed consent is a basic ethical tenet of research involving human beings, however we do not allow this with other animals even when they indicate in their own way that they are unwilling subjects (159). 4 Even if a person who is an advocate for animals is on such a committee, my personal experience on such committees has shown this to be a token gesture because the control of the vote is made up of people who in some way have a vested interest in having the projects done or who do not rigorously apply logical ethical principles in making decisions. ...
... Also at issue is the scientific appropriateness of using one species as a "model" for another (4,156). Research involving the induction of diseases in healthy subjects is not scientifically valid. ...
This paper discusses the harmful and fatal use of non-human animals in research. It argues and demonstrates that such use can be scientifically invalid if the results are applied to humans. Alternatives to such use are discussed in the context of being more defensible morally and scientifically. It calls for a change in attitude in order to institute available alternatives and develop others.
Keywords: alternative, animal use committee, animal welfare, compassion, ethics, human animal, informed consent, kindness, morality, non-human animal, research, scientific method, species differences
... Studies of MP did not halt with conclusion of NASCIS III, and more recent experiments are the subject of an extensive literature review addressing problems in translating animal data to human applications (Akhtar et al., 2009). This review is commendable in showing the mix of conflicting results obtained in recent MP acute SCI studies along with many cogent problems in study designs coupled with other issues the author raised in a previous review on animal modeling (Akhtar et al., 2008) (summarized in Table 26.1). ...
... Post-injury management of animals with regards to housing, support care, handling is different across laboratories * Based on reviews published by Akhtar et al. (2008Akhtar et al. ( , 2009. Many inherent and inescapable differences exist between experimental and human spinal cord injury that place significant demand on the robustness of preclinical data. ...
Advances in the neurobiology of spinal cord injury (SCI) have prompted increasing attention to opportunities for moving experimental strategies towards clinical applications. Preclinical studies are the centerpiece of the translational process. A major challenge is to establish strategies for achieving optimal translational progression while minimizing potential repetition of previous disappointments associated with clinical trials. This chapter reviews and expands upon views pertaining to preclinical design reported in recently published opinion surveys. Subsequent discussion addresses other preclinical considerations more specifically related to current and potentially imminent cellular and pharmacological approaches to acute/subacute and chronic SCI. Lastly, a retrospective and prospective analysis examines how guidelines currently under discussion relate to select examples of past, current, and future clinical translations. Although achieving definition of the "perfect" preclinical scenario is difficult to envision, this review identifies therapeutic robustness and independent replication of promising experimental findings as absolutely critical prerequisites for clinical translation. Unfortunately, neither has been fully embraced thus far. Accordingly, this review challenges the notion "everything works in animals and nothing in humans", since more rigor must first be incorporated into the bench-to-bedside translational process by all concerned, whether in academia, clinical medicine, or corporate circles.
... However, systemic use of MPED in excessive dosages might create serious problems. Thus, the use of MPED is currently contentious, and several animal trials have raised doubt regarding its neuroprotective impact (Rabchevsky et al., 2002;Akhtar et al., 2009). Recent studies have shown that the use of topical MPED or MPED conveyed by specific carriers can greatly enhance motor function after SCI by reducing glucocorticoid side effects (Baltin et al., 2021;Suetsugu et al., 2021). ...
The regenerative capacity of the central nervous system is very limited and few effective treatments are currently available for spinal cord injury. It is therefore a priority to develop new drugs that can promote structural and functional recovery after spinal cord injury. Previous studies have shown that peptides can promote substantial repair and regeneration of injured tissue. While amphibians have a pronounced ability to regenerate the spinal cord, few studies have investigated the effect of amphibian spinal cord-derived peptides on spinal cord injury. Here we report for the first time the successful identification and isolation of a new polypeptide, VD11 (amino acid sequence: VDELWPPWLPC), from the spinal cord of an endemic Chinese amphibian (Odorrana schmackeri). In vitro experiments showed that VD11 promoted the secretion of nerve growth factor and brain-derived neurotrophic factor in BV2 cells stimulated with lipopolysaccharide, as well as the proliferation and synaptic elongation of PC12 cells subjected to hypoxia. In vivo experiments showed that intravertebral injection of VD11 markedly promoted recovery of motor function in rats with spinal cord injury, alleviated pathological damage, and promoted axonal regeneration. Furthermore, RNA sequencing and western blotting showed that VD11 may affect spinal cord injury through activation of the AMPK and AKT signaling pathways. In summary, we discovered a novel amphibian-derived peptide that promotes structural and functional recovery after spinal cord injury.
... A systematic review of 62 pre-clinical studies investigating the effects of methylprednisolone (MP) on functional outcomes of acute SCIs found that beneficial effects of MP administration were only observed in 34% of studies, while no effects were observed in 58% and mixed results in 8%. 18 Some of the promising early results, however, supported proceeding to RCTs, which have endeavored establishment of the optimal timing and effective dosages of steroid administration in an attempt to enhance neurological recovery in patients with acute traumatic SCIs. [6][7][8][9] FIG. 1. Flow chart showing the data preparation process and the numbers of participants included in this study. ...
Immunomodulatory therapeutics represent a potential neuroprotective strategy for the management of acute spinal cord injury (SCI). One of the most intensely debated neuroprotective drugs has been methylprednisolone sodium succinate (MPSS). MPSS was initially investigated for its role in mitigating lipid peroxidation. More recently, the anti-inflammatory/immunomodulatory properties of MPSS have been increasingly appreciated. Over the past two decades, several systematic reviews and clinical practice guidelines related to MPSS use in SCI have been published. The goal of this study was to investigate the temporal changes in the use of steroids at North American Clinical Trials Network (NACTN) centers and to correlate these with the evolution in published literature and guidelines. Data on patients enrolled from 2008 - 2018 in the prospective, multicenter NACTN registry, and in whom information related to the use of steroids was available, were analyzed. Patients were stratified as to whether they received steroids or not. The primary outcome was the change in the rate of steroid use per year between 2008 and 2018. Secondary outcomes included cardiac, gastrointestinal & genitourinary (GIGU), pulmonary and dermatologic complications. We identified 608 patients, of whom 171 (28.1%) were given steroids. In 2008 and 2009, the prevailing paradigm across NACTN centers was in favor of steroid administration and as such 70% (n=56) of patients received steroids in 2008 and 71.9% (n=46) in 2009. An abrupt practice reversal was observed in 2010, whereby only 19.7% of patients (n=14) received steroids, a trend that continued over subsequent years. Increasing literature in the 2000s arguing against the use of steroids culminated in the 2013 CNS/AANS practice guidelines for the management of acute SCI. These guidelines recommended against the use of MPSS for the treatment of acute SCI. Over the following years (2013-2018), steroids continued to be an uncommonly used therapeutic option in NACTN centers (range 3.9-16.9%). Patients receiving steroids had significantly higher rates of pulmonary complications (87%, n=147) compared to those not receiving steroids (73%, n=265; p=0.0003). However, compared to patients receiving steroids, those who did not receive steroids had significantly higher rates of cardiac (40%, [n=146] versus 23%, [n=39]; p=0.0001) and gastrointestinal/genitourinary complications (55%, [n=189], versus 31%, [n=52]; p<0.0001). The 2013 AANS/CNS guidelines and preceding literature appeared to have an impact on dramatically lowering the rates of corticosteroid use for acute SCI in NACTN sites after 2009. Of note, this analysis may not reflect the impact of the 2017 AO Spine Clinical Practice guidelines, which suggested the use of methylprednisolone as a valid practice option for acute SCI, especially for cervical injuries. Enhanced patient involvement in the clinical decision-making process and opportunities to personalize SCI management exist in reference to the use of MPSS in acute SCI.
... Moreover, in Parkinson disease, many therapeutic options that have shown promising results in rats and non-human primate models have proved harmful in humans. Hence, to analyze the relevance of animal research to human health, the efficacy of animal experimentation should be examined systematically [94,95]. At the same time, the development of hyperoxaluria and renal failure (up to dialysis) after ileal-jejunal bypass was unexpected because this procedure was not preliminarily evaluated on an animal model [96]. ...
Animal experimentation is widely used around the world for the identification of the root causes of various diseases in humans and animals and for exploring treatment options. Among the several animal species, rats, mice and purpose-bred birds comprise almost 90% of the animals that are used for research purpose. However, growing awareness of the sentience of animals and their experience of pain and suffering has led to strong opposition to animal research among many scientists and the general public. In addition, the usefulness of extrapolating animal data to humans has been questioned. This has led to Ethical Committees’ adoption of the ‘four Rs’ principles (Reduction, Refinement, Replacement and Responsibility) as a guide when making decisions regarding animal experimentation. Some of the essential considerations for humane animal experimentation are presented in this review along with the requirement for investigator training. Due to the ethical issues surrounding the use of animals in experimentation, their use is declining in those research areas where alternative in vitro or in silico methods are available. However, so far it has not been possible to dispense with experimental animals completely and further research is needed to provide a road map to robust alternatives before their use can be fully discontinued.
... Steroids, with the most common drug used in this survey being MPSS (53.7%; n = 168), are potent synthetic glucocorticoids, which are thought to counteract the inflammatory response encountered during the secondary injury phase of traumatic SCI through upregulation of antiinflammatory cytokines and blockage of lipid peroxidation of neuronal cell membranes. 8,9 While newer studies have shown inconsistent results related to the efficacy of MPSS treatment in animal models of SCI, 10 historical results from preclinical studies showing enhanced tissue sparing and neuronal survival after administration of intravenous (IV) MPSS 8,9 supported proceeding to large-scale randomized clinical trials (RCTs) investigating the efficacy and safety of MPSS in patients with acute SCIs. ...
Study Design
Cross-sectional, international survey.
Objectives
To examine current international practices as well as knowledge, adoption, and barriers to guideline implementation for acute spinal cord injury (SCI) management.
Methods
A survey was distributed to members of AO Spine. The questionnaire was structured to obtain demographic data and preferred acute SCI practices surrounding steroid use, hemodynamic management, and timing of surgical decompression.
Results
593 members completed the survey including orthopaedic surgeons (54.3%), neurosurgeons (35.6%), and traumatologists (8.4%). Most (61.2%) respondents were from low and middle-income countries (LMICs). 53.6% of physicians used steroids for the treatment of acute SCIs. Respondents from LMICs were more likely to administer steroids than HICs (178 vs. 78; P < .001). 331 respondents (81.5%) answered that patients would receive mean arterial pressure (MAP) targeted treatment. In LMICs, SCI patients were less likely to be provided with MAP-targeted treatment (76.9%) as compared to HICs (89%; P < .05). The majority of respondents (87.8%) reported that patients would benefit from early decompression. Despite overwhelming evidence and surgeons’ responses that would offer early surgery, 62.4% of respondents stated they encounter logistical barriers in their institutions. This was particularly evident in LMICs, where 57.9% of respondents indicated that early intervention was unlikely to be accomplished, while only 21.1% of respondents from HICs stated the same ( P < .001).
Conclusion
This survey highlights challenges in the implementation of standardized global practices in the management of acute SCI. Future research efforts will need to refine SCI guidelines and address barriers to guideline implementation.
... Similarly, use of other drugs before and after surgery might also require controlling, or recording for inclusion as an analytical covariable. For instance, glucocorticoids have been examined for their effects in numerous studies (31), albeit without strong evidence of effect. More recently, opiates, specifically kappa opioids, have been implicated in worsening outcomes in experimental animals with spinal cord injury (32). ...
There is a clear need for new methods of treatment of acute disc herniation in dogs, most obviously to address the permanent loss of function that can arise because of the associated spinal cord injury. Clinical trials form the optimal method to introduce new therapies into everyday clinical practice because they are a reliable source of unbiased evidence of effectiveness. Although many designs are available, parallel cohort trials are most widely applicable to acute disc herniation in dogs. In this review another key trial design decision—that between pragmatic and explanatory approaches—is highlighted and used as a theme to illustrate the close relationship between trial objective and design. Acute disc herniation, and acute spinal cord injury, is common in dogs and there is a multitude of candidate interventions that could be trialed. Most current obstacles to large-scale clinical trials in dogs can be overcome by collaboration and cooperation amongst interested veterinarians.
... A meta-analysis of animal experiments concluded that "beneficial effects of MP administration were obtained in 34% of the studies, no effects in 58%, and mixed results in 8%. The results were inconsistent both among and within species, even when attempts were made to detect any patterns in the results through subgroup analyses" [32]. Due to its privileged role as the only FDA-approved pharmacological intervention in human SCI patients, MP is nonetheless often included in pre-clinical research. ...
Background:
Spinal cord injury (SCI) is a highly debilitating pathology without curative treatment. One of the most promising disease modifying strategies consists in the implantation of stem cells to reduce inflammation and promote neural regeneration. In the present study we tested a new human bone marrow-derived stromal cell preparation (bmSC) as a therapy of SCI.
Methods:
Spinal cord contusion injury was induced in adult male rats at thoracic level T9/T10 using the Infinite Horizon impactor. One hour after lesion the animals were treated with a sub-occipital injection of human bmSC into the cisterna magna. No immune suppression was used. One dose of bmSC consisted, on average, of 2.3 million non-manipulated cells in 100 μL suspension, which was processed out of fresh human bone marrow from the iliac crest of healthy volunteers. Treatment efficacy was compared with intraperitoneal injections of methylprednisolone (MP) and saline. The recovery of motor functions was assessed during a surveillance period of nine weeks. Adverse events as well as general health, weight and urodynamic functions were monitored daily. After this time, the animals were perfused, and the spinal cord tissue was investigated histologically.
Results:
Rats treated with bmSC did not reject the human implants and showed no sign of sickness behavior or neuropathic pain. Compared to MP treatment, animals displayed better recovery of their SCI-induced motor deficits. There were no significant differences in the recovery of bladder control between groups. Histological analysis at ten weeks after SCI revealed no differences in tissue sparing and astrogliosis, however, bmSC treatment was accompanied with reduced axonal degeneration in the dorsal ascending fiber tracts, lower Iba1-immunoreactivity (IR) close to the lesion site and reduced apoptosis in the ventral grey matter. Neuroinflammation, as evidenced by CD68-IR, was significantly reduced in the MP-treated group.
Conclusions:
Human bmSC that were prepared by negative selection without expansion in culture have neuroprotective properties after SCI. Given the effect size on motor function, implantation in the acute phase was not sufficient to induce spinal cord repair. Due to their immune modulatory properties, allogeneic implants of bmSC can be used in combinatorial therapies of SCI.
... Unfortunately, due to the lack of detail on the type and doses of corticosteroids, it is difficult to assess the importance of these results and they should be treated with caution. Nevertheless these results warrant further investigation especially given that nowadays, corticosteroids have been mostly abandoned from treatment recommendations for dogs with SCI and particularly IVDE due to the lack of proven efficacy for recovery of walking and known side effects [10,[23][24][25][26][27]. As for timing of surgery, we may have uncovered an important reason to consider corticosteroid use in severely injured dogs and further studies are needed to determine whether or not this class of drugs could be beneficial in a very specific population of dogs at higher risk of PMM. ...
Background:
Progressive myelomalacia (PMM) is a usually fatal complication of acute intervertebral disc extrusion (IVDE) in dogs but its risk factors are poorly understood. The objective of this retrospective case-control study was to identify risk factors for PMM by comparing dogs with complete sensorimotor loss following IVDE that did and did not develop the disease after surgery. We also investigated whether any risk factors for PMM influenced return of ambulation. Medical records of client-owned dogs with paraplegia and loss of pain perception that underwent surgery for IVDE from 1998 to 2016, were reviewed. Dogs were categorized as PMM yes or no based on clinical progression or histopathology. Walking outcome at 6 months was established. Signalment, onset and duration of signs (categorized), steroids, non-steroidal anti-inflammatory drugs (yes or no), site of IVDE (lumbar intumescence or thoracolumbar) and longitudinal extent of IVDE were retrieved and their associations with PMM and walking outcome were examined using logistic regression.
Results:
One hundred and ninety seven dogs were included, 45 with and 152 without PMM. A 6-month-outcome was available in 178 dogs (all 45 PMM dogs and 133 control dogs); 86 recovered walking (all in the control group). Disc extrusions at the lumbar intumescence were associated with PMM (p = 0.01, OR: 3.02, CI: 1.3-7.2). Surgery performed more than 12 h after loss of ambulation was associated with PMM (OR = 3.4; CI = 1.1-10.5, p = 0.03 for 12-24 h and OR = 4.6; CI = 1.3-16.6, p = 0.02 for the > 24 h categories when compared with the ≤12 h category). Treatment with corticosteroids was negatively associated with PMM (OR: 3.1; CI: 1.3-7.6, p = 0.01). The only variable to affect walking outcome was longitudinal extent of IVDE (OR = 2.6; CI = 1.3-5.3, p = 0.006).
Conclusion:
Dogs with lumbar intumescence IVDE are at increased risk of PMM. Timing of surgery and corticosteroid use warrant further investigations. PMM and recovery of walking are influenced by different factors.
... Conceivably, the inflammatory effects of substances such as S100A8 and S100A9, however harmful they may be initially, are necessary preliminaries with net benefits to the overall repair process, and lead later to neural-specific effects. Consistent with these ideas, three of the four top perturbagen classes that resembled the effect of 2 h of stimulation (Table 6) are known to produce improvements in SCI: PPARs agonists (Park et al., 2007), angiotensin receptor antagonists (Guler et al., 2010) and glucocorticoid receptor agonists, although this last group's benefits in SCI are more controversial (Akhtar et al., 2009). Furthermore, all three classes inactivate inflammatory pathways, such as those controlled by NF-κB (Bekhbat et al., 2017;Labandeira-Garcia et al., 2017;Villapol, 2018). ...
The spinal cord after injury shows altered transcription in numerous genes. We tested in a pilot study whether the nucleus raphé magnus, a descending serotonergic brainstem region whose stimulation improves recovery after incomplete spinal cord injury (SCI), can influence these transcriptional changes. Rats received 2 h of low-frequency electrical stimulation in the raphé magnus 3 days after an impact contusion at segment T8. Comparison groups lacked injuries or activated stimulators or both. Immediately following stimulation, spinal cords were extracted, their RNA transcriptome sequenced, and differential gene expression quantified. Confirming many previous studies, injury primarily increased inflammatory and immune transcripts and decreased those related to lipid and cholesterol synthesis and neuronal signaling. Stimulation plus injury, contrasted with injury alone, caused significant changes in 43 transcripts (39 increases, 4 decreases), all protein-coding. Injury itself decreased only four of these 43 transcripts, all reversed by stimulation, and increased none of them. The non-specific 5-HT7 receptor antagonist pimozide reversed 25 of the 43 changes. Stimulation in intact rats principally caused decreases in transcripts related to oxidative phosphorylation, none of which were altered by stimulation in injury. Gene ontology (biological process) annotations comparing stimulation with either no stimulation or pimozide treatment in injured rats highlighted defense responses to lipopolysaccharides and microorganisms, and also erythrocyte development and oxygen transport (possibly yielding cellular oxidant detoxification). Connectivity maps of human orthologous genes generated in the CLUE database of perturbagen-response transcriptional signatures showed that drug classes whose effects in injured rats most closely resembled stimulation without pimozide include peroxisome proliferator-activated receptor agonists and angiotensin receptor blockers, which are reportedly beneficial in SCI. Thus the initial transcriptional response of the injured spinal cord to raphé magnus stimulation is upregulation of genes that in various ways are mostly protective, some probably located in recently arrived myeloid cells.
... methylprednisolone have previously been advocated as neuroprotectants in spinal injuries; however, their impact on functional outcome is debatable. 38,39 In small animals, treatment with corticosteroids is associated with potentially fatal gastrointestinal disturbances. 40 It is likely that farm animals are at the same risk of mucosal damage which may develop into lethal abomasal or intestinal perforation. ...
Objective The aim of this study was to describe the signalment, clinical presentation, diagnostic findings, medical and surgical treatment and outcome of 22 farm animals diagnosed with a vertebral fracture or luxation.
Study design Medical records of 22 farm animals (7 goats, 6 alpacas, 5 cattle, 3 sheep and 1 deer) were reviewed for signalment, history, presenting clinical signs and neurological examination findings, clinicopathological results, diagnostic imaging, final diagnosis, medical and surgical management, clinical progression and outcome.
Results Animals' age ranged from 1 day to 15 years. Neurological examination findings included decreased motor function (20/22), recumbency (14/22), altered mentation (13/22), cranial nerve deficits (4/22) and lack of nociception (3/22). Lesions were localized to the atlanto-occipital region (2/22), C1 to C5 (7/22), C6 to T2 (4/22), T3 to L3 (3/22), and L4 to S1 (6/22). Diagnoses included vertebral fracture only (4/22), luxation only (5/22) or both vertebral fracture and luxation (13/22). In five cases, no therapy was attempted, while 12 cases were treated medically and five cases were treated surgically. Surgical interventions included manual reduction (n = 1); arthrodesis (n = 2); laminectomy (n = 1); and laminectomy with pin fixation, cerclage wire and polymethylmethacrylate bridging (n = 1). Five of the 22 cases survived to hospital discharge; two of these were treated surgically.
Conclusion The cervical region was most commonly affected. Prognosis for these injuries in farm animals is guarded.
... When publication bias against negative animal studies exists, it will lead to an overestimate of the value of animal studies. It is likely that if unpublished studies were to be included, then SRs would show more studies with no effect in animals (Akhtar, Pippin and Sandusky, 2009). Checklists and tools have been proposed to help improve SRs and meta-analyses (Hooijmans et al., 2014;Moher et al., 2009). ...
The 1st chapter 'Refinement on the way to replacement: Are we doing what we can?' of 'Animal Experimentation: Working Towards a Paradigm Change' starts by exploring the application of several refinement methods in practice, commencing with current housing and husbandry standards and a discussion about the benefits of a “culture of care”, followed by assessing important experimental refinements. To further assess the quality of animal-based research, it reviews necessary refinements in planning, conduct, and reporting practices of animal studies. The chapter then looks at feasible ways to reduce and replace animal use by first discussing tools to appraise animal studies that could lead to a significant reduction of animal experiments and thus numbers of animals used, and then reflecting on what the scientific community has been doing to move towards replacement of animals in research, testing, and education.
... In Parkinson's disease, several therapies that appeared promising in both NHPs and rat models observed inappropriate outcome in humans (Lane and Dunnett, 2008). The role of animal experiment in relevance to human health, animal experimentation's efficacy has been subjected to little systematic scrutiny (Akhtar, 2015;Akhtar et al., 2009). Standardization of laboratory settings and procedures (Macleod et al., 2004;O' Neil et al., 1999) highlight the systematic differences in the results of experiments in these labs (Crabbe et al., 1999). ...
Various upcoming techniques can be used in replacement of experiments requiring animal sacrifice or products of animal sacrifice. In many instances these techniques provide more reproducibility and control of parameter, compared to experiments involving animal or animal products. Use of these techniques can avoid the question of the animal sacrifice during experiment and subsequently permission of ethical approval. In silico simulation, informatics, 3D cell culture models, organ-on-chips are some innovative technology which can reduce the number of animals sacrifice. Scientist evolved some innovative culture procedures and production of animal friendly affinity reagents which are free from the product of animal sacrifice. Direct investigation on human body for treatment as well as further research, electronic health record is also helpful in the reduction of animals sacrifice in biomedical investigations. These techniques and strategies of research can be more cost effective as well as more relevant to various issues related to the human health. Some medical blunder has also been reported after the successful testing of drugs on animal’s model. Hence, the reliability of animal experiment in context with human health is questionable.
Alternative to animal experiments help to reduce the number of animals required for research up to certain extent but is not able to eliminate the need for animals in research completely. Wisely use of animals in teaching & research is expected and the importance of animal experimentation in futuristic development in life science cannot be ignored.
... During the development of such new drugs, numerous drug candidates (usually a few thousand) are screened in a high-throughput manner using cells cultured in plastic culture dishes and fewer than 100 effective candidates are selected. Then, the cytotoxicity of drug candidates is tested in a dose-dependent manner using the same two-dimensional (2D) culture dishes [4,5]. In the next preclinical stage, $115 million animals are used worldwide each year for experiments to ensure these drugs safety and efficacy [6]. ...
In this study, we demonstrate cell culture platforms that can provide a microenvironment similar to in vivo conditions so that in vivo-compatible drug testing results can be obtained from the in vitro experiments. To realize such in vivo microenvironment-mimetic platforms, different culture platforms such as a three-dimensional (3D) cell aggregate film, fluidic environment within a microfluidic system or extracellular matrix (ECM) coating were established. The tumor cell growth rate and sensitivity to doxorubicin (DOX) were studied using the glioblastoma cell line T98G. When 3 D spheroids were cultured, they grew significantly slower than under other culture conditions. When the cells were treated with DOX, the anticancer drug could not efficiently penetrate the 3 D spheroids to inhibit cell growth. When cultured on the Matrigel-coated culture vessel, T98G cells grew even in the presence of DOX, demonstrating chemoresistance. Nonetheless, in the 2D culture plate and in the microfluidic chip, cell growth decreased with DOX treatment and the binding ability was lost. These results indicate that the cells reacted differently to the same anticancer drug depending on the culture microenvironment. We believe that the development of a more physiologically relevant tumor cell culture platform will lead to more reliable antitumor drug responses.
... Within the context of traumatic spinal cord injury (SCI), preclinical animal studies have demonstrated mixed results with regard to the neuroprotective efficacy of MPSS. [1][2][3][4] From the standpoint of clinical investigation, randomized trials, namely, the National Acute Spinal Cord Injury Studies (NASCIS), investigating the potential efficacy and safety of MPSS, have formed the basis for the largest therapeutic studies completed in the history of SCI research. Although interpretation of, and reaction to, the results of these studies have varied over time, their publication led to the widespread adoption of this therapy by clinicians throughout the world. ...
Study Design
Systematic review and meta-analysis.
Objective
The objective of this study was to conduct a systematic review to assess the comparative effectiveness and safety of high-dose methylprednisolone sodium succinate (MPSS) versus no pharmacological treatment in patients with traumatic spinal cord injury (SCI).
Methods
A systematic search was performed in PubMed and the Cochrane Collaboration Library for literature published between January 1956 and June 17, 2015. Included studies were critically appraised, and Grades of Recommendation Assessment, Development and Evaluation methods were used to determine the overall quality of evidence for primary outcomes. Previous systematic reviews on this topic were collated and evaluated using the Assessment of Multiple Systematic Reviews scoring system.
Results
The search yielded 723 citations, 13 of which satisfied inclusion criteria. Among these, 6 were primary research articles and 7 were previous systematic reviews. Based on the included research articles, there was moderate evidence that the 24-hour NASCIS II (National Acute Spinal Cord Injury Studies) MPSS regimen has no impact on long-term neurological recovery when all postinjury time points are considered. However, there is also moderate evidence that subjects receiving the same MPSS regimen within 8 hours of injury achieve an additional 3.2 points (95% confidence interval = 0.10 to 6.33; P = .04) of motor recovery compared with patients receiving placebo or no treatment.
Conclusion
Although safe to administer, a 24-hour NASCIS II MPSS regimen, when all postinjury time points are considered, has no impact on indices of long-term neurological recovery. When commenced within 8 hours of injury, however, a high-dose 24-hour regimen of MPSS confers a small positive benefit on long-term motor recovery and should be considered a treatment option for patients with SCI.
... Within the context of acute spinal cord injury (SCI), preclinical animal studies have demonstrated mixed results with regard to the neuroprotective actions of methylprednisolone sodium succinate (MPSS). [1][2][3][4] Several randomized controlled trials, including the National Acute Spinal Cord Injury Studies (NASCIS), have investigated the efficacy and safety of MPSS in patients with acute SCI and comprise the largest therapeutic studies completed in the history of SCI research. [5][6][7][8] Although the interpretation of and reaction to the results of these studies have varied over time, their publication led to the widespread adoption of this therapy by clinicians throughout the world. ...
Introduction
The objective of this guideline is to outline the appropriate use of methylprednisolone sodium succinate (MPSS) in patients with acute spinal cord injury (SCI).
Methods
A systematic review of the literature was conducted to address key questions related to the use of MPSS in acute SCI. A multidisciplinary Guideline Development Group used this information, in combination with their clinical expertise, to develop recommendations for the use of MPSS. Based on GRADE (Grading of Recommendation, Assessment, Development and Evaluation), a strong recommendation is worded as “we recommend,” whereas a weaker recommendation is indicated by “we suggest.”
Results
The main conclusions from the systematic review included the following: (1) there were no differences in motor score change at any time point in patients treated with MPSS compared to those not receiving steroids; (2) when MPSS was administered within 8 hours of injury, pooled results at 6- and 12-months indicated modest improvements in mean motor scores in the MPSS group compared with the control group; and (3) there was no statistical difference between treatment groups in the risk of complications. Our recommendations were: (1) “We suggest not offering a 24-hour infusion of high-dose MPSS to adult patients who present after 8 hours with acute SCI”; (2) “We suggest a 24-hour infusion of high-dose MPSS be offered to adult patients within 8 hours of acute SCI as a treatment option”; and (3) “We suggest not offering a 48-hour infusion of high-dose MPSS to adult patients with acute SCI.”
Conclusions
These guidelines should be implemented into clinical practice to improve outcomes and reduce morbidity in SCI patients.
... It leads to significant recovery from primary tissue damage and secondary neuropathic pain and inflammation in SCI. MP use has been reported to significantly improve motor nerve activity in cases of SCI [8][9][10]. ...
Purpose: To prepare and characterize in situ gel-forming implants of methylprednisolone for the treatment of spinal cord injuries. Methods: In situ hydrogels of methylprednisolone were prepared by dispersing polylactide glycolic acid (PLGA) polymer and methylprednisolone in N-methyl-pyrrolidone solvent, and subsequent membrane sterilization. Hydrogels were prepared using varying concentrations of PLGA polymer. The physicochemical properties of hydrogels, including visual appearance, clarity, pH, viscosity, drug content, and in vitro drug release, were characterized. In vivo studies were performed to examine anti-inflammatory activity (paw edema test) and in vivo motor function activity in a rat spinal injury model after injecting the hydrogels into rats. Results: The physicochemical properties of the gels were satisfactory. F1, F2, F3, and F4 formulations showed 99.67, 95.29, 88.89 and 88.20% drug release, respectively, at the end of 7 days. In vivo anti-inflammatory activity was highest for F1 (62.85%). Motor function activity scores (arbitrary scale) for the F1, F2, F3 and F4 formulations were 4.82 ± 0.12, 4.70 ± 0.12, 4.68 ± 0.02, and 4.60 ± 0.05, respectively, and were higher (p < 0.05) for F1, F2 and F3) than for the standard (methylprednisolone, 30 mg/kg body weight, iv; activity score, 4.59 ± 0.20). Conclusions: The in situ hydrogels of methylprednisolone developed may be useful for the effective management of spinal cord injuries in patients. However, further investigations are required to ascertain their suitability for clinical use. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.
... It has been reported to show significant recovery from tissue damage, neuropathic pain and inflammation. Studies have also shown improvement in motor nerve activity with the use of MPSS in spinal injury [13,14]. This study aims to develop the polymeric implantable device of MPSS and to study its effect on traumatic spinal injured rats with paraplegia. ...
Purpose: To improve the effectiveness and reduce the systemic side effects of methylprednisolone in traumatic spinal injuries, its polymeric implants were prepared using chitosan and sodium alginate as the biocompatible polymers. Methods: Implants of methylprednisolone sodium succinate (MPSS) were prepared by molding the drug-loaded polymeric mass obtained after ionotropic gelation method. The prepared implants were evaluated for drug loading, in vitro drug release and in vivo performance in traumatic spinal-injury rat model with paraplegia. Results: All the implant formulations were light pale solid matrix with smooth texture. Implants showed 86.56 ± 2.07 % drug loading. Drug release was 89.29 ± 1.25 % at the end of 7 days. Motor function was evaluated in traumatic spinal injury-induced rats in terms of its movement on the horizontal bar. At the end of 7 days, the test group showed the activity score (4.75 ± 0.02) slightly higher than that of standard (4.62 ± 0.25), but the difference was not statistically different (p > 0.05). Conclusion: MPSS-loaded implants produces good recovery in traumatic spinal-injury rats. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.
... The analysis of studies in animals and humans showed that the use of the MP may not be effective in SCI treatment. Besides, a large number of studies have shown that using of MP can have many side effects such as infections, pneumonia and septic shock, diabetes complications, and delayed wound healing [10][11][12][13]. We observed the negative effects of the injection of large doses of MP in acute period of a change in the functional state of the hind limb muscles of rat in chronic period too. ...
An increasing number of treatments for spinal cord injury (SCI) out of the laboratories and in clinical trials pass. Many of them are used as soon as possible after the injury with the hope of weakening the secondary damage and maximize the preservation of nerve tissue. The aim of the study was to evaluate the effects metilprednizalonium and motor training at an experimental spinal cord injury in rats. To investigate the status of the peripheral neuromuscular system registered motor response (M-response) muscles. In the early period after spinal cord injury was observed, a decrease of the maximum amplitude of M-response. With that, in the group of animals with the introduction of metilprednizalonium, amplitude of M-response was higher than that without drug therapy. Combined therapy metilprednizalonium and motor training has a positive effect on the recovery of motor function in chronic period after contusion spinal cord injury in rats.
... A systematic review in the field of evidence-based medicine is the highest level of medical evidence, and accordingly the required standards have already been developed. 6 Recently, systematic reviews in the animal experimentation field have attracted great attention, [7][8][9] although there are not adequate guidelines for assessing the quality of experimental animal studies. In this regard, a few groups of researchers focused on the development of publication guidelines in order to improve the reporting transparency, which makes future systematic reviews more feasible and allows the researchers to replicate previously published papers. ...
... A systematic review in the field of evidence-based medicine is the highest level of medical evidence, and accordingly the required standards have already been developed. 6 Recently, systematic reviews in the animal experimentation field have attracted great attention, [7][8][9] although there are not adequate guidelines for assessing the quality of experimental animal studies. In this regard, a few groups of researchers focused on the development of publication guidelines in order to improve the reporting transparency, which makes future systematic reviews more feasible and allows the researchers to replicate previously published papers. ...
Study design:
This is a Delphi study.
Objectives:
Defining variables that potentially influence the outcomes of an animal study regarding pathophysiology of traumatic spinal cord injury (TSCI).
Setting:
This study was conducted in Iran.
Methods:
A modified two-round Delphi study was conducted. As the first round, an initial questionnaire was developed on the basis of literature and a series of focus group discussions. In the second round, the participants were asked to score the items through a 10-point scale. Consensus was achieved through the following criteria: (1) the median of scores has to be at 7.5 or higher, and (2) at least 70% of participants need to rate 7 or higher. Also, the inter-rater reliability analysis was performed to determine consistency among raters using the Kappa coefficient and Cronbach's alpha.
Results:
Twenty-one experts participated in our study. From the first round of the study, a 47-item checklist was developed. By considering the aforementioned criteria for consensus building on extremely important factors, we reached a 15-item checklist including species, strain, method and level of injury, control group, genetic background, severity of injury, attrition, use of appropriate test, blindness, method of allocation to treatments, regulation and ethics, age/weight, bladder expression, number of animals/group and statistics. The inter-rater reliability for the raters was found to be Kappa=0.82 (P<0.001). A Cronbach's alpha of 0.9 for all the questions indicated high internal consistency.
Conclusion:
This study introduces a checklist of variables that potentially influence the outcomes of animal studies regarding TSCI pathophysiology and describe its validity and reliability.Spinal Cord advance online publication, 22 December 2015; doi:10.1038/sc.2015.215.
... 28 Although numerous studies report the beneficial effect of MPSS in experimental models of spinal cord injury, a critical evaluation of the literature reported that 58% of experimental studies were unable to show benefit, as compared to 34% that did. 29 Comparing studies is extremely difficult because of the use of different injury models, species, treatment protocols and outcome measures, and the challenges in translating such results into clinical use are well recognized. 30 The NASCIS II and III trials were the first clinical trials in humans to demonstrate a benefit with MPSS treatment in patients with acute spinal cord injury 31,32 and their results have been replicated by some 33 and not by others, 34 leading to ongoing controversy over their study design, the impact of adverse effects, and the longterm benefits. ...
Background:
Acute intervertebral disk herniation (IVDH) is a common cause of spinal cord injury in dogs and currently there is no proven medical treatment to counter secondary injury effects. Use of methylprednisolone sodium succinate (MPSS) or polyethylene glycol (PEG) as neuroprotectants is advocated but controversial because neither treatment has been tested in placebo-controlled, randomized, blinded trials in dogs.
Hypothesis:
Polyethylene glycol will improve the outcome of severe spinal cord injury caused by IVDH compared to MPSS or placebo.
Animals:
Client-owned dogs with acute onset of thoracolumbar IVDH causing paralysis and loss of nociception for <24 hours.
Methods:
Dogs were randomized to receive MPSS, PEG, or placebo; drugs appeared identical and group allocation was masked. Drug administration was initiated once the diagnosis of IVDH was confirmed and all dogs underwent hemilaminectomy. Neurologic function was assessed 2, 4, 8, and 12 weeks postoperatively using an open field gait score (OFS) as the primary outcome measure. Outcomes were compared by the Wilcoxon rank sum test.
Results:
Sixty-three dogs were recruited and 47.6% recovered ambulation. 17.5% developed progressive myelomalacia but there was no association with group. There was no difference in OFS among groups. Although full study power was not reached, conditional power analyses indicated the futility of continued case recruitment.
Conclusions:
This clinical trial did not show a benefit of either MPSS or PEG in the treatment of acute, severe thoracolumbar IVDH when used as adjunctive medical treatment administered to dogs presenting within 24 hours of onset of paralysis.
... This review concluded that there was a need to develop validated methods for analyzing these treatments. 14 In humans, the results have been contradictory: according to Andrade, there was no relationship between application of the NASCIS II protocol and the patients' evolution. 15 However, among patients treated using MP and surgery, there was greater motor recovery than among patients who did not undergo this treatment. ...
The aim here was to conduct a review of the literature on pharmacological therapies for modifying the neurological status of patients with spinal cord injuries. The PubMed database was searched for articles with the terms “spinal cord injury AND methylprednisolone/GM1/apoptosis inhibitor/calpain inhibitor/naloxone/tempol/tirilazad”, in Portuguese or in English, published over the last five years. Older studies were included because of their historical importance. The pharmacological groups were divided according to their capacity to interfere with the physiopathological mechanisms of secondary injuries. Use of methylprednisolone needs to be carefully weighed up: other anti-inflammatory agents have shown benefits in humans or in animals. GM1 does not seem to have greater efficacy than methylprednisolone, but longer-term studies are needed. Many inhibitors of apoptosis have shown benefits in in vitro studies or in animals. Naloxone has not shown benefits. Tempol inhibits the main consequences of oxidation at the level of the spinal cord and other antioxidant drugs seem to have an effect superior to that of methylprednisolone. There is an urgent need to find new treatments that improve the neurological status of patients with spinal cord injuries. The benefits from treatment with methylprednisolone have been questioned, with concerns regarding its safety. Other drugs have been studied, and some of these may provide promising alternatives. Additional studies are needed in order to reach conclusions regarding the benefits of these agents in clinical practice.
... O estudo concluiu que é necessário desenvolver métodos validados para analisar esses tratamentos. 14 Em humanos, os estudos são contraditórios: segundo Andrade, não foi encontrada relação entre a aplicação do protocolo NASCIS II e a evolução dos pacientes. 15 No entanto, em doentes tratados com MP e cirurgia houve uma maior recuperação motora do que nos pacientes não submetidos a esse tratamento. ...
The aim here was to conduct a review of the literature on pharmacological therapies for modifying the neurological status of patients with spinal cord injuries. The PubMed database was searched for articles with the terms «spinal cord injury AND methylprednisolone / GM1 / apoptosis inhibitor / calpain inhibitor / naloxone / tempol / tirilazad», in Portuguese or in English, published over the last five years. Older studies were included because of their historical importance. The pharmacological groups were divided according to their capacity to interfere with the physiopathological mechanisms of secondary injuries. Use of methylprednisolone needs to be carefully weighed up: other anti‐inflammatory agents have shown benefits in humans or in animals. GM1 does not seem to have greater efficacy than methylprednisolone, but longer‐term studies are needed. Many inhibitors of apoptosis have shown benefits in in vitro studies or in animals. Naloxone has not shown benefits. Tempol inhibits the main consequences of oxidation at the level of the spinal cord and other antioxidant drugs seem to have an effect superior to that of methylprednisolone. There is an urgent need to find new treatments that improve the neurological status of patients with spinal cord injuries. The benefits from treatment with methylprednisolone have been questioned, with concerns regarding its safety. Other drugs have been studied, and some of these may provide promising alternatives. Additional studies are needed in order to reach conclusions regarding the benefits of these agents in clinical practice.
... were concerned with the methodological quality of the included trials. 46,47,49,51,53 One study49 used a methodological quality assessment checklist that included four items from other reviews. 56-58 Study quality was assessed using a checklist of 9 items adapted from good laboratory practice guidelines for in vivo stroke modeling 59 and the CAMARADES quality checklist 44 in 2 studies. ...
Spinal cord injury (SCI) is a devastating condition affecting young, healthy individuals worldwide. Existing agents have inadequate therapeutic efficacy, and some are associated with side effects. Our objective is to summarize and critically assess the neurological recovery and antioxidant effects of curcumin for treatment of SCI in rat models. PUBMED, EMBASE and Chinese databases were searched from their inception date to February 2014. Two reviewers independently selected animal studies that evaluated neurological recovery and antioxidant effects of curcumin compared with placebo in rats with SCI, extracted data and assessed the methodological quality. A pairwise analysis and a network meta-analysis were performed. Eight studies with adequate randomization were selected and included in the systematic review. Two studies had a higher methodological quality. Overall, curcumin appears to significantly improve neurological function, as assessed using Basso, Beattie, Bresnahan (BBB) locomotor rating scale (4 studies, n=132, pooled MD=3.09, 95% CI=3.40 to 4.45, P=0.04), in a random effects model and decrease the malondialdehyde (MDA) using a fixed effects model (4 studies, n=56, pooled MD=-1.00, 95% CI=-1.59 to -0.42, P=0.00008). The effect size, assessed using the BBB scale, increased gradually with increasing curcumin dosage. The difference between low-dose and high-dose curcumin using the BBB scale was statistically significant. Neurological recovery and antioxidant effects of curcumin were observed in rats with SCI despite poor study methodological quality. An assessment of the methodological quality of animal model SCI studies is required, and good methodological quality should be valued in systematic reviews of animal studies. Key words: systematic review; network meta-analysis; spinal cord injury; curcumin.
... Doubt developed both for significant high-dose-related side effects as well as the modest functional improvement. This was consistent from a meta-analysis of MP efficacy in preclinical reported studies that found considerable inconsistencies [92]. Despite more than two decades the controversy is still unsettled, and many reviewers consider it to be of marginal benefit in improving functional outcome. ...
Introduction:
Spinal cord injury (SCI) occurs within seconds, but host responses may take years. Although life expectancy has increased, half of the survivors end up as paraplegics, with many indeed as quadriplegics. Host responses may have multiple effects ranging from inhibiting inflammation to preventing repair and regeneration. Efforts seek to translate exciting results from unsatisfactory animal models to humans.
Areas covered:
The author reviews the current basic and translational research for SCI treatment that: i) limits secondary injury; and ii) enhances endogenous repair and regeneration. The article provides an emphasis on pro-inflammatory factors (TNF-α, high-mobility group B protein 1) that are targeted to encourage healing.
Expert opinion:
Research in the coming years needs to be directed at therapeutic agents - whether drugs, biologics or biomaterials - that encourage repair and regeneration and, at the same time, limit cell death and axonal lesions. The author believes that the process of harnessing the power of these innate responses will remain the challenge for the future in the quest for effective therapeutic options.
... In addition to rodents, those prior experimental studies also included cats, dogs, and monkeys. Generally speaking, the benefits of spinal cord decompression in those animal studies appear to be optimized when blood flow and electrophysiological parameters were restored earlier than 6 h; however, this did depend on the model of SCI, animal species or strain, methodological quality, outcome measure, use of anesthesia, and time period of follow-up (Akhtar et al., 2009). The critical analysis of the current pre-clinical evidence strongly indicated that time of spinal cord compression is a key determinant of recovery after SCI and, hence, there is a biological rationale to support early spinal cord compression for improved out- comes. ...
While the recommendations for spine surgery in specific cases of acute traumatic spinal cord injury (SCI) are well recognized, there is considerable uncertainty regarding the role of the timing of surgical decompression of the spinal cord in the management of patients with SCI. Given this, we sought to critically review the literature regarding the pre-clinical and clinical evidence on the potential impact of timing of surgical decompression of the spinal cord on outcomes after traumatic SCI. The primary literature search was performed using MEDLINE, CINAHL, EMBASE, and Cochrane databases. A secondary search strategy incorporated articles referenced in prior meta-analyses and systematic and nonsystematic review articles. Two reviewers independently assessed every study with regard to eligibility, level of evidence, and study quality. Of 198 abstracts of pre-clinical studies, 19 experimental studies using animal SCI models fulfilled our inclusion and exclusion criteria. Despite some discrepancies in the results of those pre-clinical studies, there is evidence for a biological rationale to support early decompression of the spinal cord. Of 153 abstracts of clinical studies, 22 fulfilled the inclusion and exclusion criteria. While the vast majority of the clinical studies were level-4 evidence, there were two studies of level-2b evidence. The quality assessment scores varied from 7 to 25 with a mean value of 12.41. While 2 of 22 clinical studies assessed feasibility and safety, 20 clinical studies examined efficacy of early surgical intervention to stabilize and align the spine and to decompress the spinal cord; the most common definitions of early operation used 24 and 72 h after SCI as timelines. A number of studies indicated that patients who undergo early surgical decompression can have similar outcomes to patients who received a delayed decompressive operation. However, there is evidence to suggest that early surgical intervention is safe and feasible and that it can improve clinical and neurological outcomes and reduce health care costs. Based on the current clinical evidence using a Delphi process, an expert panel recommended that early surgical intervention should be considered in all patients from 8 to 24 h following acute traumatic SCI.
... The current evidence for steroid use in adults is very weak. A systematic review of the animal literature on the use of corticosteroids showed a positive benefit in only 59% of the studies (Akhtar et al., 2009). ...
Spinal Cord Injury (SCI) in the pediatric population is relatively rare but carries significant psychological and physiological consequences. An interdisciplinary group of experts composed of medical and surgical specialists treating patients with SCI formulated the following questions: 1) What is the epidemiology of pediatric spinal cord injury and fractures?; 2) Are there unique features of pediatric SCI which distinguish the pediatric SCI population from adult SCI?; 3) Is there evidence to support the use of neuroprotective approaches, including hypothermia and steroids, in the treatment of pediatric SCI? A systematic review of the literature using multiple databases was undertaken to evaluate these three specific questions. A search strategy composed of specific search terms (Spinal Cord Injury, Paraplegia, Quadriplegia, tetraplegia, lapbelt injuries, seatbelt injuries, cervical spine injuries and Pediatrics) returned over 220 abstracts that were evaluated and by two observers. Relevant abstracts were then evaluated and papers were graded using the Downs and Black method. A table of evidence was then presented to a panel of experts using a modified Delphi approach and the following recommendation was then formulated using a consensus approach: Pediatric patients with traumatic SCI have different mechanisms of injury and have a better neurological recovery potential when compared to adults. Patients with SCI before their adolescent growth spurt have a high likelihood of developing scoliosis. Because of these differences, traumatic SCI should be highly suspected in the presence of abnormal neck or neurological exam, a high-risk mechanism of injury or a distracting injury even in the absence of radiological anomaly.
... 43,46-48 A recent systematic review of MP that included 62 studies showed beneficial effects of MP administration were obtained in 34% of the studies, no effects in 58%, and mixed results in 8%, thus demonstrating the barriers to the translation of animal study findings on the effectiveness of MP in the treatment of acute SCI to humans. 46 As in the animal studies, debate still exists in clinical practice. 49-51 It cannot be said at this point that MP has no beneficial effect in the treatment of acute SCI, but it seems clear that if any benefit exists, it is probably small and has not been demonstrated by the NASCIS studies. ...
Approximately 11 000 people suffer traumatic spinal cord injury (TSCI) in the United States, each year. TSCI incidences vary from 13.1 to 52.2 per million people and the mortality rates ranged from 3.1 to 17.5 per million people. This review examines the critical care of TSCI. The discussion will focus on primary and secondary mechanisms of injury, spine stabilization and immobilization, surgery, intensive care management, airway and respiratory management, cardiovascular complication management, venous thromboembolism, nutrition and glucose control, infection management, pressure ulcers and early rehabilitation, pharmacologic cord protection, and evolving treatment options including the use of pluripotent stem cells and hypothermia.
... In addition to rodents, those prior experimental studies also included cats, dogs, and monkeys. Generally speaking, the benefits of spinal cord decompression in those animal studies appear to be optimized when blood flow and electrophysiological parameters were restored earlier than 6 h; however, this did depend on the model of SCI, animal species or strain, methodological quality, outcome measure, use of anesthesia, and time period of follow-up (Akhtar et al., 2009). The critical analysis of the current pre-clinical evidence strongly indicated that time of spinal cord compression is a key determinant of recovery after SCI and, hence, there is a biological rationale to support early spinal cord compression for improved outcomes. ...
Spinal cord injury (SCI) leading to neurological deficits produces long-term effects that persist over a lifetime. Survival analysis of patients with SCI, at individual and population level, is important for public health management and the assessment of treatment achievements. The current study evaluated survival following traumatic and non-traumatic SCI worldwide. A systematic review was conducted, and all included papers were assessed for quality using a purposely designed assessment form. Survival data were presented in Kaplan-Meier curves and compared using the log-rank test. Sixteen studies were included of which 11 concerned traumatic SCI, four non-traumatic SCI, and one both. Crude standard mortality rates (SMRs) revealed that overall mortality in SCI is up to three times higher than in the general population. Survival rates were statistically significantly lower in non-traumatic SCI than in traumatic SCI (log-rank p = 0.000). Age at injury, neurological level, extent of lesion, and year of injury have been described as predictors of survival. Causes of death stem from secondary complications, with failure of the respiratory system being the leading cause. This is the first systematic literature review on survival analysis following SCI worldwide. An increase in survival over time was found. However, the SMRs of individuals with SCI still exceed those of an age-matched non-disabled population, mainly due to secondary complications. Lower survival rates were observed in non-traumatic SCI compared with traumatic SCI.
Spinal cord injury (SCI) is associated with significant physical and psychological morbidity among patients and carries major economic ramifications to both individuals and health-care systems. The ability to mitigate the damage caused by acute SCI and impact the natural history of this condition with pharmacotherapy has been a naturally enticing, yet immensely complex, prospect for many years. Advancements on this front would serve to reduce disability and have major clinical, social, and economic impact. Over the past 40 years, there have been major efforts to find an effective drug to improve functional recovery after SCI. This goal has stemmed directly from advancements in our understanding of the pathobiological mechanisms of SCI secondary injury. A number of agents have undergone preclinical examination in animal models, with a small subset of these reaching clinical trials.
Preclinical research has unveiled therapeutic options for promoting functional outcomes after spinal cord injury (SCI) via neuroprotection, rehabilitation/neuroplasticity, and repair. Such advances have drawn attention to facilitating more timely clinical studies of promising treatments for SCI. However, judicious translation entails a host of scientific and logistical considerations in addition to a sense of urgency shared throughout the SCI community at large. Neuropathic pain is among secondary consequences of spinal trauma for which therapeutic discovery and subsequent clinical translation are crucially needed. Here, we provide a perspective on challenges in bridging the preclinical-to-clinical gap with selective emphasis on cell-based repair of the injured spinal cord and reference to chronic neuropathic pain post-SCI. Focus is initially on preclinical issues that were the foundation for early trials using embryonic neural tissue. Discussion then centers on how those considerations may still apply to future translational approaches. Realizing that rationales for initiating human trials can differ widely, the goal is not to prescribe a specific translational protocol. Instead, the objective is to present views related to systematic, scientific pursuit while not losing sight of the crucial need for more rapid translational progress.
Introdução. A metilprednisolona é um tratamento farmacológico para lesões medulares traumáticas agudas, cuja recomendação do uso permanece controversa. Objetivo. Descrever as evidências do uso de metilprednisolona nos pacientes com traumatismo raquimedular. Método. Trata-se de uma revisão sistemática da literatura. Pesquisou-se nas bases Lilacs e Medline estudos clínicos randomizados de pacientes que receberam metilprednisolona no braço intervenção, em comparação com placebo ou outra droga, com início do tratamento em até 48 horas do diagnóstico do trauma. Não houve restrição de idioma ou data de publicação. Os desfechos primários avaliados foram mortalidade, função motora, sensibilidade superficial e/ou profunda, enquanto os secundários foram efeitos adversos, qualidade de vida e independência funcional. Os estudos foram avaliados quanto ao viés pelo score de Jadad, enquanto a evidência foi classificada conforme os níveis da Universidade de Oxford. Os resultados foram sumarizados de forma qualitativa. Resultados. Cinco publicações foram incluídas na análise, todas no nível um de evidência para estudos de benefício de tratamento, com 1092 pacientes randomizados. 40% dos estudos atingiram score de boa qualidade, com o mascaramento e descrição das perdas de segmento foram os que acarretaram mais rebaixamentos de pontuação. Conclusão. Não recomendamos o uso de metilprednisolona, face a ausência de benefício de melhora significativa da função motora e sensibilidade, além de não reduzir mortalidade. A independência funcional também não apresentou melhora, enquanto a qualidade de vida sequer foi avaliada nos estudos incluídos. O uso da droga também se associou à elevação de efeitos adversos.
Study design:
Level-1 Diagnostic Study.
Objective:
The purpose of this study was to evaluate the sensitivity and specificity of combined motor and sensory intraoperative neuromonitoring (IONM) for cervical spondylotic myelopathy (CSM).
Summary of background data:
Intraoperative neuromonitoring during spine surgery began with sensory modalities with the goal of reducing neurological complications. Motor monitoring was later added and purported to further increase sensitivity and specificity when used in concert with sensory monitoring. Debate continues, however, as to whether neuromonitoring reliably detects reversible neurologic changes during surgery or simply adds set-up time, cost, or mere medico-legal reassurance.
Methods:
Neuromonitoring data using combined motor and sensory evoked potentials for 540 patients with CSM undergoing anterior or posterior decompressive surgery were collected prospectively. Patients were examined postoperatively to determine the clinical occurrence of new neurologic deficit which correlated with monitoring alerts recorded per established standard criteria.
Results:
The overall incidence of positive IONM alerts was 1.3% (N = 7) all of which were motor alerts. All were false positives as no patient had clinical neurological deterioration post-operatively. The false positive rate was 1.4% (N = 146) for anterior surgeries and 1.3% (N = 394) for posteriors with no statistical difference between them (p = 1.0, Fisher's exact test). There were no false negative alerts, and all negatives were true negatives (N = 533). The overall sensitivity of detecting a new neurologic deficit was 0%, overall specificity 98.7%.
Conclusion:
Combined motor and sensory neuromonitoring for CSM patients created a confusing choice between the motor or sensory data when in disagreement in 1.3% of surgical patients. Gold standard clinical exams confirmed all motor alerts were false positives. Surgical plan was negatively altered by following false motor alerts early on, but disregarded in later cases in favor of sensory data. Neuromonitoring added set-up time and cost, but without clear benefit in this series.Level of Evidence: 4.
Objective:
Fractures of the thoracolumbar spine can cause pain, long-term reductions in quality of life (QOL), and neural deficits. The aim of this study was to investigate the effects of methylene blue (MB) on preventing postoperative pain and improving QOL in patients with throracolumbar fractures undergoing posterior pedicle screw fixation.
Methods:
Fifty patients underwent standard posterior pedicular screw fixation for stabilization of the thoracolumbar fractures: 25 received 1ml of MB solution at a concentration of 0.5% and 25 received normal saline on the soft tissue around fusion site. Primary outcomes were the control of pain, evaluated at 48h, 2 and 6 months after surgery with the use of a visual analog scale (VAS), and the improvement of QOL, assessed 2 and 6 months postoperatively by means of Oswestry Disability Index (ODI) questionnaire.
Results:
The mean VAS scores for pain were significantly lower in the MB group compared with the control group at 2 months (1.30±0.45 vs. 2.60±1.19, P<0.001) and 6 months (1.17±0.37 vs. 1.60±0.87; P=0.028) after treatment. At 2 months after the surgery, the mean ODI score was significantly lower in the MB-treated patients than the control group (20.4±10.92 vs. 34.8±15.11; P=0.001). The ODI score in the MB-treated patients was better than the control group at 6 months after the surgery (12.2±11.66 vs. 20.8±11.14; P=0.016).
Conclusion:
A single dose of MB on the soft tissue around fusion site shows promising results in terms of safety, reduction of postoperative pain, and functional results when compared with placebo 6 months after surgery.
Background:
Intramedullary spinal cord tumors (IMSCT) account for about 2%-4% of tumors of the central nervous system. Surgical resection continues to be the most effective treatment modality for most intramedullary tumors, with gross total resection leading to preserved neurologic function and improved survival. However, surgical treatment is often difficult and carries significant risk of postoperative neurologic complications. Intraoperative neuromonitoring has been shown to be of clinical importance in the surgical resection of IMSCT. The main monitoring modalities include somatosensory evoked potentials, transcranial motor evoked potentials via limb muscles or spinal epidural space (D-waves), and dorsal column mapping. These monitoring modalities have been shown to inform surgeons intraoperatively and in many cases, have led to alterations in operative decision.
Methods:
We reviewed the literature on the usefulness of intraoperative neuromonitoring for intramedullary spinal tumor resection and its role in predicting postoperative neurologic deficits. A MEDLINE search was performed (2000-2015) and 13 studies were reviewed. Detailed information and data from the selected articles were assessed and compiled. Data were extracted showing the role of monitoring in outcomes of surgery.
Conclusions:
By using intraoperative somatosensory evoked potentials, transcranial motor evoked potentials, D-waves, and dorsal column mapping, spinal injury could be prevented in most cases, thereby improving postoperative neurologic functioning and outcome in patients undergoing surgery for IMSCT.
Despite our tremendous prevention power, the fact remains that drugs are important tools in the arsenal of modern medical science. To produce new drugs, we need research. This involves applied research, that is, research directly intended to produce a new treatment. Basic, or more exploratory, research is also utilized to help direct applied research. To approve a drug for the market, regulatory requirements usually dictate at least two major stages of safety and efficacy testing. The preclinical stage includes the use of in vitro and/or animal experiments to assess whether a drug is a viable candidate for further clinical investigation based on safety and efficacy evaluations. The clinical stage is broken down into three phases. Phase 1 typically involves a small group of healthy human volunteers to test the safety of a compound. Phases 2 and 3 usually include larger groups of volunteers in controlled clinical trials to test for both safety and efficacy of the potential treatment against the targeted disease or condition. Post-marketing studies are also often required to monitor the safety of a product once in use.
Current management of spinal cord injury is restricted to initial damage limitation, supportive treatment and rehabilitative care. Whilst advancements have been made, a reversal of the injury process and repair of the cord has so far not been achieved and hence this injury has remained "incurable". However, a number of innovative new therapies for spinal cord injury are on the horizon, heralding an exciting era for this field. Ranging from pharmaceuticals and immunoglobulins to hypothermia and cell transplants, the approaches are varied. Perhaps the most high-profile new technique is the injection of Oligodendrocyte Progenitor Cells (OPCs) into the acute spinal cord lesion. Despite some reservations regarding the theory underlying this approach, it was the subject of the first clinical trial using human embryonic stem cell derivatives in humans, commenced in late 2010. However, this phase I trial was closed to future enrolment one year later, due to financial reasons. This chapter looks firstly at the current management options for SCI and their limitations. This is followed by a review of the plethora of future avenues for therapeutic development, including pharmacological, physical and cellular approaches, and an in-depth analysis of treatment with Oligodendrocyte Progenitor Cells.
Nonhuman animal ("animal") experimentation is typically defended by arguments that it is reliable, that animals provide sufficiently good models of human biology and diseases to yield relevant information, and that, consequently, its use provides major human health benefits. I demonstrate that a growing body of scientific literature critically assessing the validity of animal experimentation generally (and animal modeling specifically) raises important concerns about its reliability and predictive value for human outcomes and for understanding human physiology. The unreliability of animal experimentation across a wide range of areas undermines scientific arguments in favor of the practice. Additionally, I show how animal experimentation often significantly harms humans through misleading safety studies, potential abandonment of effective therapeutics, and direction of resources away from more effective testing methods. The resulting evidence suggests that the collective harms and costs to humans from animal experimentation outweigh potential benefits and that resources would be better invested in developing human-based testing methods.
Animal ethics committees (AECs) appeal to utilitarian principles in their justification of animal experiments. Although AECs do not grant rights to animals, they do accept that animals have moral standing and should not be unnecessarily harmed. Although many appeal to utilitarian arguments in the justification of animal experiments, I argue that AECs routinely fall short of the requirements needed for such justification in a variety of ways. I argue that taking the moral status of animals seriously--even if this falls short of granting rights to animals--should lead to a thorough revision or complete elimination of many of the current practices in animal experimentation.
Traumatic fractures of the spine are most common at the thoracolumbar junction and can be a source of great disability.
To review the most current information regarding the pathophysiology, injury pattern, treatment options, and outcomes.
Literature review.
Relevant articles, textbook chapters, and abstracts covering thoracolumbar spine fractures with and without neurologic deficit from 1960 to the present were reviewed.
The thoracolumbar spine represents a unique system from a skeletal as well as neurological standpoint. The rigid rib-bearing thoracic spine articulates with the more mobile lumbar spine at the thoracolumbar junction (T10 - L2), the site of most fractures. A complete examination includes a careful neurologic examination of both motor and sensory systems. CT scans best describe bony detail while MRI is most efficient at describing soft tissues and neurological structures. The most recent classification system is that of the new Thoracolumbar Injury Classification and Severity Score. The different fracture types include compression fractures, burst fractures - both stable and unstable -, flexion-distraction injuries and fracture dislocations. Their treatment, both operative and non-operative depends on the degree of bony compromise, neurological involvement, and the integrity of the posterior ligamentous complex. Minimally invasive approaches to the care of thoracolumbar injuries have become more popular, thus, the evidence regarding their efficacy is presented. Finally, the treatment of osteoporotic fractures of the thoracolumbar spine is reviewed, including vertebroplasty and kyphoplasty, their risks and controversies, and senile burst fractures, as well.
Thoracolumbar spine fractures remain a significant source of potential morbidity. Advances in treatment have minimized the invasiveness of our surgery and in certain stable situations, eliminated it all together.
Salvianolic acid B (Sal B), a bioactive compound isolated from the Chinese medicinal herb danshen, is commonly used for the prevention and treatment of cardiovascular disease. The present study was performed to investigate the effect of Sal B on the blood-spinal cord barrier (BSCB) after spinal cord injury (SCI) in a rat model. Sal B (1, 10, and 50 mg/kg i.v.) was administered to rats immediately following SCI. The permeability of the BSCB and spinal cord tissue water content were evaluated. Additionally, the expression levels of tight junction proteins and heme oxygenase-1 (HO-1) were monitored by Western blot analysis. Enzyme-linked immunosorbent assay analysis of spinal cord tissue homogenates was performed 24 h post-SCI to evaluate the expression of inflammation-related cytokines. In addition, the motor recovery of SCI rats was assessed using the Basso, Beattie, and Bresnahan scoring system. Compared to the SCI group, rats treated with Sal B (10, 50 mg/kg) exhibited significantly reduced spinal cord tissue water content and BSCB permeability. Further, the motor function of rats was also greatly improved by Sal B administration. The expression of pro-inflammatory factors TNF-α and NF-κB was found to be greatly increased 24 h post-SCI, and this upregulation was significantly attenuated by Sal B treatment. The expression of ZO-1 and occludin was upregulated by Sal B (10 mg/kg) treatment after SCI, and this effect was blocked by the HO-1 inhibitor ZnPP. Taken together, our results clearly indicate that Sal B attenuates SCI by promoting the repair of the damaged BSCB, demonstrating that this molecule is a novel and promising therapeutic agent for human SCI.
The activation of a delayed secondary cascade of unsatisfactory cellular and molecular responses after a primary mechanical insult to the spinal cord causes the progressive degeneration of this structure. Disturbance of ionic homeostasis is part of the secondary injury process and plays an integral role in the early stage of spinal cord injury (SCI). The secondary pathology of SCI is complex and involves disturbance of the homeostasis of K(+) , Na(+) , and Ca(2+) . The effect of ion channel blockers on chronic SCI has also been proved. In this Mini-Review, we provide a comprehensive summary of the effects of ion channel blockers on the natural responses after SCI. Combination therapy is based on the roles of ions and disturbance of their homeostasis in SCI. The effects of ion channel blockers suggest that they have potential in the treatment of SCI, although the complexity of their effects shows that further knowledge is needed before they can be applied clinically.
Studies in animals indicate that methylprednisolone and naloxone are both potentially beneficial in acute spinal-cord injury, but whether any treatment is clinically effective remains uncertain. We evaluated the efficacy and safety of methylprednisolone and naloxone in a multicenter randomized, double-blind, placebo-controlled trial in patients with acute spinal-cord injury, 95 percent of whom were treated within 14 hours of injury. Methylprednisolone was given to 162 patients as a bolus of 30 mg per kilogram of body weight, followed by infusion at 5.4 mg per kilogram per hour for 23 hours. Naloxone was given to 154 patients as a bolus of 5.4 mg per kilogram, followed by infusion at 4.0 mg per kilogram per hour for 23 hours. Placebos were given to 171 patients by bolus and infusion. Motor and sensory functions were assessed by systematic neurological examination on admission and six weeks and six months after injury. After six months the patients who were treated with methylprednisolone within eight hours of their injury had significant improvement as compared with those given placebo in motor function (neurologic change scores of 16.0 and 11.2, respectively; P = 0.03) and sensation to pinprick (change scores of 11.4 and 6.6; P = 0.02) and touch (change scores, 8.9 and 4.3; P = 0.03). Benefit from methylprednisolone was seen in patients whose injuries were initially evaluated as neurologically complete, as well as in those believed to have incomplete lesions. The patients treated with naloxone, or with methylprednisolone more than eight hours after their injury, did not differ in their neurologic outcomes from those given placebo. Mortality and major morbidity were similar in all three groups. We conclude that in patients with acute spinal-cord injury, treatment with methylprednisolone in the dose used in this study improves neurologic recovery when the medication is given in the first eight hours. We also conclude that treatment with naloxone in the dose used in this study does not improve neurologic recovery after acute spinal-cord injury.
The effects of methyl prednisolone (MPD), dimethyl sulphoxide (DMSO), and naloxone were examined in 38 albino rats after making an impact spinal cord injury on the midthoracic segments with a modified Allen's weight dropping trauma method. Somatosensorial evoked potentials (SEPs) were recorded before and 12 h and 14 d after the injury from epidurally inserted electrodes on the parietal cortex with sciatic nerve stimulations. Lower extremity motor functions of the animals were also examined. It may be concluded that in this study model, DMSO has a moderate effect which can be demonstrated clinically and through SEPs. Naloxone has no effect on the clinical outcome but causes reasonable improvement electrophysiologically.
We have studied the effects of sevoflurane on neurological outcome in a rat model of incomplete cerebral ischaemia. After institutional approval, 30 non-fasted male Sprague-Dawley rats (455-555 g) were anaesthetized, the trachea intubated and the lungs ventilated mechanically with isoflurane and 30% oxygen in air. Catheters were inserted into the right femoral artery, both femoral veins and into the right jugular vein for measurement of arterial pressure, drug administration and blood sampling. At completion of surgery, isoflurane was discontinued and the rats were allowed an equilibration period of 30 min according to the following regimens: group 1 (n = 10) received 70% nitrous oxide in oxygen and fentanyl (bolus 10 micrograms kg-1 i.v.; infusion 25 micrograms kg-1 h-1); group 2 (n = 10) received 1.98 vol% sevoflurane in oxygen and air (FIO2 0.3); group 3 (n = 10) received 1.98 vol% sevoflurane in oxygen and air (FIO2 0.3) and 40% glucose (6 ml kg-1 i.p.) 30 min before ischaemia. Ischaemia was produced by combined unilateral common carotid artery ligation and haemorrhagic hypotension to 35 mm Hg for 30 min. Temperature, arterial blood-gas variables and arterial pH were maintained within the physiological range. Plasma glucose concentration was measured before, during and after ischaemia. Neurological deficit was evaluated for 3 days after ischaemia. Neurological outcome was better in sevoflurane anaesthetized animals, regardless of the plasma glucose concentration, compared with nitrous oxide-fentanyl controls. This indicates that differences in plasma glucose concentrations do not account for the cerebral protection seen with sevoflurane.
To compare the efficacy of methylprednisolone administered for 24 hours with methyprednisolone administered for 48 hours or tirilazad mesylate administered for 48 hours in patients with acute spinal cord injury.
Double-blind, randomized clinical trial.
Sixteen acute spinal cord injury centers in North America.
A total of 499 patients with acute spinal cord injury diagnosed in National Acute Spinal Cord Injury Study (NASCIS) centers within 8 hours of injury.
All patients received an intravenous bolus of methylprednisolone (30 mg/kg) before randomization. Patients in the 24-hour regimen group (n=166) received a methylprednisolone infusion of 5.4 mg/kg per hour for 24 hours, those in the 48-hour regimen group (n=167) received a methylprednisolone infusion of 5.4 mg/kg per hour for 48 hours, and those in the tirilazad group (n=166) received a 2.5 mg/kg bolus infusion of tirilazad mesylate every 6 hours for 48 hours.
Motor function change between initial presentation and at 6 weeks and 6 months after injury, and change in Functional Independence Measure (FIM) assessed at 6 weeks and 6 months.
Compared with patients treated with methylprednisolone for 24 hours, those treated with methylprednisolone for 48 hours showed improved motor recovery at 6 weeks (P=.09) and 6 months (P=.07) after injury. The effect of the 48-hour methylprednisolone regimen was significant at 6 weeks (P=.04) and 6 months (P=.01) among patients whose therapy was initiated 3 to 8 hours after injury. Patients who received the 48-hour regimen and who started treatment at 3 to 8 hours were more likely to improve 1 full neurologic grade (P=.03) at 6 months, to show more improvement in 6-month FIM (P=.08), and to have more severe sepsis and severe pneumonia than patients in the 24-hour methylprednisolone group and the tirilazad group, but other complications and mortality (P=.97) were similar. Patients treated with tirilazad for 48 hours showed motor recovery rates equivalent to patients who received methylprednisolone for 24 hours.
Patients with acute spinal cord injury who receive methylprednisolone within 3 hours of injury should be maintained on the treatment regimen for 24 hours. When methylprednisolone is initiated 3 to 8 hours after injury, patients should be maintained on steroid therapy for 48 hours.
The demyelination process is an important factor contributing to long term sensory and motor impairments after spinal cord injury (SCI). Exposure of axonal K+ channels after demyelination may contribute to blockage of action potentials across the injury site. A K+ channel blocker, 4-aminopyridine (4-AP), has been effective in restoring some sensory and motor impairment in incomplete SCI patients. The long-term effect of this compound in chronic model of SCI is not known. In this study, after a compression injury of 50 grams in rats, a randomized treatment was initiated 3 weeks after the initial injury which was followed by daily administration of 4-AP at 2 mg/kg (n = 8), 4 mg/kg (n = 8), and 6 mg/kg (n = 8) for 4 weeks. A group of methylprednisolone (MP)-treated (30 mg/kg, n = 8) and non-treated animals (n = 8) were included for comparison. The functional motor outcome was measured in each animal at regular time points up to 4 weeks post-treatment. All animals receiving 6 mg/kg developed generalized seizure and were excluded from the study. In the other animal groups, analysis of the behavioral outcome and neuro-pathological changes were essentially similar and did not show any significant effect of treatment. Our data indicate that daily administration of 4-AP, over 4 weeks of treatment period, lacks any significant effect on axonal function in chronically injured rats. This could be due to (a) lack of significant numbers of demyelinated axons which could improve the functional outcome and (b) a treatment regimen that was not adequate to contribute to a better functional outcome. One time bolus-administration of MP at 30 mg/kg also did not ensure a better functional outcome.
The timeliness of a review of the neuropathology ofhuman spinal cord injury (SCI) centres on theincreasing interest in central axonal regeneration inthe search for a ‘cure’ of spinal paralysis. Neuropathol-ogy contributes to this end by describing the nature ofthe disorder to be cured. More broadly a knowledge ofthe neuropathology underlying SCI is essential also forthe clinician responsible for management of the patientas well as the neuroscientist working on SCI. There hasbeen spectacular progress in neurobiology in recentyears with CNS repair and regeneration now reportedby many centres. However, in order for thesediscoveries to be applied to human SCI an apprecia-tion of the neuropathology is required. The neurobiol-ogist must be aware of the nature of the condition tobe cured for the research to be relevant. Furthermore,before the experimental findings may be applied to thepatient it must be shown that the reactions to injuryare comparable in each. An outline of recent advancesin the neurobiology of experimental SCI is thereforeincluded in this review in order to bridge the gapbetween human SCI and the experimental models.Most importantly the insight provided by the complex-ity of the problem of finding a cure serves to informthose waiting for this to occur to be realistic in theirexpectations.
A renewable source of human sensory neurons would greatly facilitate basic research and drug development. We had established previously conditionally immortalized human CNS cell lines that can differentiate into functional neurons (). We report here the development of an immortalized human dorsal root ganglion (DRG) clonal cell line, HD10.6, with a tetracycline-regulatable v-myc oncogene. In the proliferative condition, HD10.6 cells have a doubling time of 1.2 d and exhibit a neuronal precursor morphology. After differentiation of clone HD10.6 for 7 d in the presence of tetracycline, v-myc expression was suppressed, and >50% of the cells exhibited typical neuronal morphology, stained positively for neuronal cytoskeletal markers, and fired action potentials in response to current injection. Furthermore, this cell line was fate-restricted to a neuronal phenotype; even in culture conditions that promote Schwann cell or smooth muscle differentiation of neural crest stem cells, HD10.6 differentiated exclusively into neurons. Moreover, differentiated HD10.6 cells expressed sensory neuron-associated transcription factors and exhibited capsaicin sensitivity. Taken together, these data indicate that we have established an immortalized human DRG cell line that can differentiate into sensory neurons with nociceptive properties. The cell line HD10.6 represents the first example of a human sensory neuronal line and will be valuable for basic research, as well as for the discovery of novel drug targets and clinical candidates.
From the beginning, the reporting of the results of National Acute Spinal Cord Injury Studies (NASCIS) II and III has been incomplete, leaving clinicians in the spinal cord injury (SCI) community to use or avoid using methylprednisolone in acute SCI on the basis of faith rather than a publicly developed scientific consensus. NASCIS II was initially reported by National Institutes of Health announcements, National Institutes of Health facsimiles to emergency room physicians, and the news media. The subsequent report in the New England Journal of Medicine implied that there was a positive result in the primary efficacy analysis for the entire 487 patient sample. However, this analysis was in fact negative, and the positive result was found only in a secondary analysis of the subgroup of patients who received treatment within 8 hours. In addition, that subgroup apparently had only 62 patients taking methylprednisolone and 67 receiving placebo. The NASCIS II and III reports embody specific choices of statistical methods that have strongly shaped the reporting of results but have not been adequately challenged or or even explained. These studies show statistical artifacts that call their results into question. In NASCIS II, the placebo group treated before 8 hours did poorly, not only when compared with the methylprednisolone group treated before 8 hours but even when compared with the placebo group treated after 8 hours. Thus, the positive result may have been caused by a weakness in the control group rather than any strength of methylprednisolone. In NASCIS III, a randomization imbalance occurred that allocated a disproportionate number of patients with no motor deficit (and therefore no chance for recovery) to the lower dose control group. When this imbalance is controlled for, much of the superiority of the higher dose group seems to disappear. The NASCIS group's decision to admit persons with minor SCIs with minimal or no motor deficit not only enables statistical artifacts it complicates the interpretation of results from the population actually sampled. Perhaps one half of the NASCIS III sample may have had at most a minor deficit. Thus, we do not know whether the results of these studies reflect the severely injured population to which they have been applied. The numbers, tables, and figures in the published reports are scant and are inconsistently defined, making it impossible even for professional statisticians to duplicate the analyses, to guess the effect of changes in assumptions, or to supply the missing parts of the picture. Nonetheless, even 9 years after NASCIS II, the primary data have not been made public. The reporting of the NASCIS studies has fallen far short of the guidelines of the ICH/FDA and of the Evidence-based Medicine Group. Despite the lucrative "off label" markets for methylprednisolone in SCI, no Food and Drug Association indication has been obtained. There has been no public process of validation. These shortcomings have denied physicians the chance to use confidently a drug that many were enthusiastic about and has left them in an intolerably ambiguous position in their therapeutic choices, in their legal exposure, and in their ability to perform further research to help their patients.
Strains of mice that show characteristic patterns of behavior are critical for research in neurobehavioral genetics. Possible
confounding influences of the laboratory environment were studied in several inbred strains and one null mutant by simultaneous
testing in three laboratories on a battery of six behaviors. Apparatus, test protocols, and many environmental variables were
rigorously equated. Strains differed markedly in all behaviors, and despite standardization, there were systematic differences
in behavior across labs. For some tests, the magnitude of genetic differences depended upon the specific testing lab. Thus,
experiments characterizing mutants may yield results that are idiosyncratic to a particular laboratory.
Objective.
—To compare the efficacy of methylprednisolone administered for 24 hours with methyprednisolone administered for 48 hours or tirilazad mesylate administered for 48 hours in patients with acute spinal cord injury.Design.
—Double-blind, randomized clinical trial.Setting.
—Sixteen acute spinal cord injury centers in North America.Patients.
—A total of 499 patients with acute spinal cord injury diagnosed in National Acute Spinal Cord Injury Study (NASCIS) centers within 8 hours of injury.Intervention.
—All patients received an intravenous bolus of methylprednisolone (30 mg/kg) before randomization. Patients in the 24-hour regimen group (n=166) received a methylprednisolone infusion of 5.4 mg/kg per hour for 24 hours, those in the 48-hour regimen group (n=167) received a methylprednisolone infusion of 5.4 mg/kg per hour for 48 hours, and those in the tirilazad group (n=166) received a 2.5 mg/kg bolus infusion of tirilazad mesylate every 6 hours for 48 hours.Main Outcome Measures.
—Motor function change between initial presentation and at 6 weeks and 6 months after injury, and change in Functional Independence Measure (FIM) assessed at 6 weeks and 6 months.Results.
—Compared with patients treated with methylprednisolone for 24 hours, those treated with methylprednisolone for 48 hours showed improved motor recovery at 6 weeks (P=.09) and 6 months (P=.07) after injury. The effect of the 48-hour methylprednisolone regimen was significant at 6 weeks (P=.04) and 6 months (P=.01) among patients whose therapy was initiated 3 to 8 hours after injury. Patients who received the 48-hour regimen and who started treatment at 3 to 8 hours were more likely to improve 1 full neurologic grade (P=.03) at 6 months, to show more improvement in 6-month FIM (P=.08), and to have more severe sepsis and severe pneumonia than patients in the 24-hour methylprednisolone group and the tirilazad group, but other complications and mortality (P=.97) were similar. Patients treated with tirilazad for 48 hours showed motor recovery rates equivalent to patients who received methylprednisolone for 24 hours.Conclusions.
—Patients with acute spinal cord injury who receive methylprednisolone within 3 hours of injury should be maintained on the treatment regimen for 24 hours. When methylprednisolone is initiated 3 to 8 hours after injury, patients should be maintained on steroid therapy for 48 hours.
Objectives. Randomized trials are widely recognized as providing the most reliable evidence for assessing efficacy and safety of therapeutic interventions. This evidence base is used to evaluate the current status of methylprednisolone (MPSS) in the early treatment of acute spinal cord injury. Methods. Medline, CINAHL, and other specified databases were searched for MeSH headings “methylprednisolone and acute spinal cord injury.” The Cochrane Library and an existing systematic review on the topic were also searched. Results. Five randomized controlled trials were identified that evaluated high-dose MPSS for acute spinal cord injury. Three trials by the NASCIS group were of high methodologic quality, and a Japanese and French trial of moderate to low, methodologic quality. Meta-analysis of the final result of three trials comparing 24-hour high-dose MPSS with placebo or no therapy indicates an average unilateral 4.1 motor function score improvement (95% confidence interval 0.6–7.6, P = 0.02) in patients treated with MPSS. This neurologic recovery is likely to be correlated with improved functional recovery in some patients. The safety of this regimen of MPSS is evident from the spinal cord injury trials and a systematic review of 51 surgical trials of high-dose MPSS. Conclusion. High-dose MPSS given within 8 hours of acute spinal cord injury is a safe and modestly effective therapy that may result in important clinical recovery for some patients. Further trials are needed to identify superior pharmacologic therapies and to test drugs that may sequentially influence the postinjury cascade.
This chapter outlines the history and practice of animal spinal cord contusion models, with particular emphasis on the Multicenter Animal Spinal Cord Injury Study (MASCIS) Impactor model of rat spinal cord injury. Most human spinal cord injuries involve contusions of the spinal cord. Many investigators have long used weight-drop contusion animal models to study the pathophysiology and genetic responses of spinal cord injury. All spinal cord injury therapies tested to date in clinical trial were validated in such models. In recent years, the trend has been towards use of rats for spinal cord injury studies. The MASCIS Impactor is a well-standardized rat spinal cord contusion model that produces very consistent graded spinal cord damage that linearly predicts 24-h lesion volumes, 6-week white matter sparing, and locomotor recovery in rats. All aspects of the model, including anesthesia for male and female rats, age rather than body weight criteria, and arterial blood gases were empirically selected to enhance the consistency of injury.
Report by Paul Wallman, Clinical Fellow Search checked by Kevin Mackway-Jones, Consultant
A 40 year old man is involved in a road traffic accident. He has bony disruption at C7/T1 with acute spinal cord injury. He has no associated head injury and no other life threatening …
From the beginning, the reporting of the results of National Acute Spinal Cord Injury Studies (NASCIS) II and III has been incomplete, leaving clinicians in the spinal cord injury (SCI) community to use or avoid using methylprednisolone in acute SCI on the basis of faith rather than a publicly developed scientific consensus. NASCIS II was initially reported by National Institutes of Health announcements, National Institutes of Health facsimiles to emergency room physicians, and the news media. The subsequent report in the New England Journal of Medicine implied that there was a positive result in the primary efficacy analysis for the entire 487 patient sample. However, this analysis was in fact negative, and the positive result was found only in a secondary analysis of the subgroup of patients who received treatment within 8 hours. In addition, that subgroup apparently had only 62 patients taking methylprednisolone and 67 receiving placebo. The NASCIS II and III reports embody specific choices of statistical methods that have strongly shaped the reporting of results but have not been adequately challenged or or even explained. These studies show statistical artifacts that call their results into question. In NASCIS II, the placebo group treated before 8 hours did poorly, not only when compared with the methylprednisolone group treated before 8 hours but even when compared with the placebo group treated after 8 hours. Thus, the positive result may have been caused by a weakness in the control group rather than any strength of methylprednisolone. In NASCIS III, a randomization imbalance occurred that allocated a disproportionate number of patients with no motor deficit (and therefore no chance for recovery) to the lower dose control group. When this imbalance is controlled for, much of the superiority of the higher dose group seems to disappear. The NASCIS group's decision to admit persons with minor SCIs with minimal or no motor deficit not only enables statistical artifacts it complicates the interpretation of results from the population actually sampled. Perhaps one half of the NASCIS III sample may have had at most a minor deficit. Thus, we do not know whether the results of these studies reflect the severely injured population to which they have been applied. The numbers, tables, and figures in the published reports are scant and are inconsistently defined, making it impossible even for professional statisticians to duplicate the analyses, to guess the effect of changes in assumptions, or to supply the missing parts of the picture. Nonetheless, even 9 years after NASCIS II, the primary data have not been made public. The reporting of the NASCIS studies has fallen far short of the guidelines of the ICH/FDA and of the Evidence-based Medicine Group. Despite the lucrative “off label” markets for methylprednisolone in SCI, no Food and Drug Association indication has been obtained. There has been no public process of validation. These shortcomings have denied physicians the chance to use confidently a drug that many were enthusiastic about and has left them in an intolerably ambiguous position in their therapeutic choices, in their legal exposure, and in their ability to perform further research to help their patients.
A model simulating acute-compressive spinal cord trauma at the second lumbar spinal cord segment (100 g, 300 seconds) was used to evaluate the efficacy of a vehicle control, methylprednisolone sodium succinate (MPSS), and a 21-aminosteroid compound (U74389G). Dogs were allocated into one of five treatment groups (A to E) using ultrasonographic determination of spinal cord diameters to ensure even distribution of spinal cord diameters among the treatment groups. Initial dosages of the vehicle control (A), methylprednisolone (30 mg/kg of body weight) (B), or U74389G (30 mg/kg, 3 mg/kg, or 10 mg/kg of body weight) (C, D, or E, respectively) were administered intravenously 30 minutes after trauma. Dosages were reduced by one-half for 2 and 6 hour treatments. Then every 4 hours for 42 hours, dosages were reduced one-third and one-sixth from the original dose of methylprednisolone and U74389G, respectively. Neurological examinations were performed daily for 21 days. Histopathological examination of the traumatized spinal cord showed malacic and degenerative lesions. Although significant differences in some portions of the neurological and histopathologic examinations were observed, clinical efficacy for MPSS and U74389G could not be established in this model.
We used a new injury device that produces consistent spinal cord contusion injuries (T8) in rats to compare the behavioral and histologic effects of methylprednisolone sodium succinate (MPSS) administration, the clinical standard of therapy after acute spinal cord injury (ASCI), with the 21-aminosteroid, U-74006F (U74), and the TRH analogue, YM-14673 (YM), at different trauma doses. Three sequential experiments were conducted: Experiment 1 . U74 (3.0/1.5/1.5 mg/kg; 10/5/5 mg/kg; 30/15/15 mg/kg), MPSS (30/15/15 mg/kg), or vehicle were administered intravenously (iv) at 5 min, 2 and 6 h after the injury (n = 8/group). U74 (10/5/5 mg/kg) and MPSS animals scored better than controls (Days 8-43) in open field walking (OFW); no other differences were seen between groups. Experiment 2. Dose-response evaluation of MPSS determined more effective doses. Groups (n = 16) receiving 30/30/30/30 mg/kg and 60/60/60/60 mg/kg iv at 5 min and 2, 4, and 6 h after the injury had better OFW scores than controls (Days 8-29; Day 29). Both groups performed better than controls (Days 8-29) on inclined plane (IP); 30 mg/kg animals scored higher on Day 29. Percentage tissue spared (%TS) at the lesion center was greater for 60 mg/kg animals (23.4%) than controls (17.3%). Experiment 3. Compounds were administered as in experiment 2 (n = 15/group); MPSS (60/30/30/30 mg/kg) and YM (1/1/1/1 mg/kg and 1 mg/kg/day ip) were most effective. YM and MPSS combination produced no additive effects. YM animals scored better than MPSS and control animals in OFW (Days 8-29) and better than controls on IP (Days 8-29; Day 29) and grid walking (Day 29), MPSS animals scored better than controls on IP (Days 8-29 ). YM and MPSS groups had greater %TS than controls.
The validity of reproduction of the controlled contusion injury to the spinal cord in the experimental animal is questioned. The dynamic pathology involving the microvasculature within the first two hours is illustrated using light microscopy. After 15-30 minutes swelling of axons and disruption of myelin sheaths become evident in most areas of white matter. After four hours microcysts have formed in the columns of white matter and are evidence of irreversible damage. Swelling of the cord following injury results from congestion, extravasation and intracellular swelling of neurones, rather than from any demonstrable increase in extracellular fluid. Oedema was only demonstrated with perfusion fixation. Isotope and contrast myelography were compared in the identification of the degree and extent of spinal cord swelling. Significant improvement in motor power was found in a group of paraplegic sheep treated with alpha-methyl paratyrosine. There was no significant improvement in the degree of recovery of motor power or sensation in those animals treated with intrathecal methyl prednisolone (Depo-Medrol). The histopathology in the crushed spinal cord tissue of the treated and untreated animals at various intervals of time was compared. Some possible explanations for the different patterns of clinical recovery in the treated animals are discussed.
The effect of the 21-aminosteroid U74006F on neurologic recovery after a spinal cord compression trauma was investigated in rats. The compression was induced by a blocking weight technique, in which a 35 g (moderate injury) or a 50 g (severe injury) weight was applied for 5 minutes to an 11 mm2 plate over the midthoracic spinal cord. One hour after trauma, the severely injured animals were treated either with U74006F, 3 mg/kg, methylprednisolone, 30 mg/kg, or vehicle, whereas the moderately injured animals received U74006F, 3 mg/kg or vehicle. Neurologic hind limb function was evaluated by the inclined plane technique. On day 1 after trauma, subtotal paraparesis occurred in the 35 g group treated with vehicle (31 +/- 1 degrees, mean +/- SEM) on the inclined plane vs 64 +/- 1 degrees before trauma) and complete paraplegia in the 50 g group (22 +/- 1 degrees). Treatment with U74006F resulted in less hind limb weakness in the 35 g group (42 +/- 2 degrees) but had no beneficial effect in the 50 g group (25 +/- 2 degrees). Neurologic function gradually improved in the 35 g groups over the 9-day observation period. However, those animals treated with U74006F were significantly better over the entire period. In the 50 g group, no recovery from paraplegia was noted over the 4 day observation period in any of the three groups. These results suggest that after weight-induced spinal cord trauma, U74006F is associated with improved neurologic function in moderately injured, but not severely injured animals.
A study of the dose-response effects of naloxone and methylprednisolone after rat ventral spinal cord injury is presented. The spinal cord injury model used herein is unique in that it results in a ventral compression of the spinal cord without the need for a prior laminectomy. This allows for a close approximation of the human clinicopathological situation. There was a statistically significant positive effect on neurological outcome with a naloxone dose of 2.5 mg/kg, whereas higher and lower doses yielded little or no influence on outcome. Methylprednisolone was observed to offer similar results. These results, however, did not achieve statistical significance. The early administration of moderately high doses (45-60 mg/kg), however, offered the best results. The responses to the treatment regimens presented here offer hope for spinal cord injury victims. The observed dose-response relationships indicate that erroneous conclusions may arise from studies using inappropriate doses of narcotic antagonists, as well as other drugs.
The effect of methylprednisolone (MP) on neurologic recovery and spinal cord blood flow (SCBF) was investigated up to 4 days after a spinal cord compression injury in rats. The injury was produced at midthoracic level by applying a load of 35 g on a 2.2 x 5.0 mm compression plate for 5 min, which resulted in transient paraparesis. MP was given as a bolus dose of 30 mg/kg i.v. 60 min after injury (n = 20) and controls were given saline (n = 10). The motor performance was assessed daily as the capacity angle on the inclined plane and SCBF was measured by 14C-iodoantipyrine autoradiography on Days 1 or 4. On Day 1 the capacity angle was reduced from about 63 degrees preoperatively to 33 +/- 2 degrees (mean +/- SEM) in the control group and to 50 +/- 1 degrees in the group treated with MP (p less than 0.05). Thereafter there was a slight improvement in both groups, but the difference persisted throughout the observation period. On Day 4 both gray and white matter SCBF was better preserved in MP-treated animals than in the control group (59 +/- 4 versus 49 +/- 3 ml/min/100 g tissue for gray matter and 13.6 +/- 0.6 versus 10.7 +/- 0.8 ml/min/100 g tissue for white matter). Posttraumatic treatment with MP, thus, improved both the neurologic recovery during the first 4 days and SCBF as measured on Day 4. It is speculated that the effect of MP is at least partly exerted on the vascular bed.
The effect of large doses of methylprednisolone sodium succinate (MPSS) and two protease inhibitors, leupeptin and bestatin, on experimental acute spinal cord injury was evaluated by morphometric analysis of degenerating axons with the aid of an automated image analyzer. Spinal cord injury was produced by epidural compression with a surgical clip on the T-11 segment in rats. The extent of axonal damage was assessed in Rexed's lamina VIII in the L-6 segment by measuring the amount of silver grains, representing degenerating axons and their terminals, using the Fink-Heimer method. The severity of axonal damage was expressed as the degeneration index: that is, the amount of silver grains in experimental animals/the amount of silver grains in cord-transected animals. When examined on the 7th postoperative day, axonal degeneration in MPSS-treated rats was significantly decreased, with an average degeneration index difference of 6 (p less than 0.05). Increased preservation of axons was seen in the leupeptin-treated rats sacrificed 7, 10, and 14 days after trauma. The difference in the degeneration index between the leupeptin-treated and untreated groups was 16 on Day 7 (p less than 0.001), 12 on Day 10 (p less than 0.001), and 13 on Day 14 (p less than 0.01). Bestatin had no beneficial effect. The implications for the use of calcium-activated neutral protease inhibitors in acute spinal cord injury are discussed.
Beginning 30 minutes after compression trauma of the upper lumbar (L-2) spinal cord, cats were treated with either a high-dose regimen of methylprednisolone (MP) administered as the sodium salt of the 21-succinate ester (Solu-Medrol sterile powder) or the MP vehicle. Animals were randomly assigned to either treatment group (10 cats per group), and all personnel were blind as to which animals received vehicle or drug. The intensive 48-hour dosing regimen was designed to maintain therapeutic tissue levels of MP and consisted of an initial 30 mg/kg intravenous bolus of MP; 2 and 6 hours later additional 15 mg/kg MP doses were administered by intravenous bolus. Immediately following the bolus given at 6 hours, a continuous MP infusion of 2.5 mg/kg/hr was started. The infusion was stopped abruptly at 48 hours with no dose tapering. Animals in the vehicle group received an equivalent volume of MP vehicle. The total MP dose administered over 48 hours was 165 mg/kg. Animals were evaluated weekly for neurological recovery based upon a 12-point functional scale which assessed general mobility, running, and stair-climbing. Mean recovery scores at 1 month after injury (+/- standard error of the mean) were: vehicle group (seven cats) 3.7 +/- 0.9, and MP group (10 cats) 8.7 +/- 0.2; (p less than 0.001). Histological evaluation of the spinal cords revealed a strong negative correlation between neurological recovery and size of the spinal cord cavity at 1 month (r = -0.88). Three of 10 animals in the vehicle group became ill and had to be dropped from the study, whereas all of the 10 MP-treated animals survived in excellent health. The results demonstrate the therapeutic effectiveness and low incidence of side effects associated with an intensive MP dose regimen for treatment of experimental spinal cord injury.
Compression trauma of the cat spinal cord induces a very rapid alteration in the lipid metabolism of cellular membranes, including lipid hydrolysis with release of fatty acids including arachidonate, production of biologically active eicosanoids, and loss of cholesterol. This disturbance of cellular membranes can directly damage cells and can lead to the secondary development of tissue ionic imbalance, ischemia, edema, and inflammation with neuronophagia. Pretreatment with either the synthetic glucocorticoid methylprednisolone sodium succinate (MPSS) or the antioxidants vitamin E and selenium (Se) completely prevented the loss of cholesterol and partially inhibited lipolysis and prostanoid production. Treatment with MPSS significantly reduced the postinjury tissue necrosis and paralysis. Preliminary evidence indicates that pretreatment with vitamin E and Se also protected against the effects of spinal cord injury (SCI). We speculate that the ability of these agents to preserve function after SCI may, in part, reside in their capacity to limit the trauma-induced changes in lipid metabolism.
We investigated the probability of survival of mouse spinal neurons in monolayer cultures after transection lesions of dendrites made within 400 microns of the perikarya. Based on a total of 650 lesioned neurons, the following observations were made. First, neuronal survival is a function of lesion distance from the perikaryon and of process diameter at the lesion site. For an average lesion diameter of 3 microns, dendrite transections at 50 microns, 100 microns, and 150 microns were associated with survival probabilities of 30%, 53%, and 70%, respectively. Second, the fate of the injured cells was definitely established 24 hours after injury and very likely was determined as early as 2 hours. Third, early stages of deterioration leading to cell death were associated with cytoplasmic phase brightness on light microscopy, correlating with an appearance of numerous, small, electron-lucent vacuoles and swollen mitochondria on electron microscopy. The cytoplasm of these moribund cells stained darkly and contained no visible microtubules or neurofilaments. Fourth, the magnitude and time course of injury potentials recorded at the somata were a function of the lesion distance and did not return to prelesion levels within 30 minutes after transection. Fifth, at 24 hours after injury, the average membrane potential of lesioned neurons was 8% below that of control neurons. Sixth, at a lesion distance of approximately 300 microns both the injury potential and the probability of cell death approach zero. We conclude that, in the model system used, neuronal survival after dendrite amputation depends on physical parameters of the lesion that determine the magnitude of the injury current reaching the soma. Survival is not assured if the injury is inflicted within 250 microns of the cell body, and cell death is likely for lesions within 50 microns of the soma. The below-normal membrane potentials at 24 hours after injury suggest a possible greater vulnerability of recovering neurons to secondary insults. The characteristic mitochondrial disruption and loss of microtubules implies that the calcium component of the injury current contributes to cell death.
Corticosteroids are frequently used in the treatment of spinal trauma, although neither experimental nor clinical evidence to support their use is persuasive. Recently there have been claims that extremely high doses ("megadoses") of corticosteroids (equivalent to 15 to 30 mg/kg of methylprednisolone) improve neurological recovery compared to results with traditional steroid doses. The authors have compared the effect of megadose dexamethasone and methylprednisolone therapy to that of saline treatment following traumatic cervical spinal injury in the cat. During 6 weeks postinjury, neurological recovery did not differ significantly in corticosteroid-treated and saline-treated animals. Moreover, histopathological changes in the spinal cord were similar in methylprednisolone- and saline-treated cats. Corticosteroid-treated animals had a higher mortality rate than did control animals, with the predominant cause of death being neurogenic pulmonary edema. It is concluded that megadose corticosteroid treatment does not improve neurological recovery in this experimental model of spinal injury, and is associated with increased mortality.
Steroids are commonly used in the treatment of acute spinal cord injury patients although a review of the literature fails to define a consistent regimen for administration with regard to optimal preparation or dosage or schedule. This study was designed to evaluate the effect of exogenous steroids on the outcome of experimental spinal cord injury and the effect of experimental spinal cord injury on endogenous cortisol production. Thirty female rhesus monkeys received a 660 gm cm lesion to the T10 spinal cord. They were randomly placed into one of six groups of five animals each. Two groups were controls used to assess the endogenous cortisol response to spinal cord injury. These animals received no steroids. The other four groups received one of two commonly used steroid preparations. All animals were evaluated serially for neurological status using motor testing and for general physical status. Serial cortisol determinations were obtained for an eight-week post injury period. The steroid groups showed some benefit from treatment when compared to the untreated controls. There were no significant differences in physical condition between treated and control groups. Of special interest was the response of endogenous cortisol production to spinal cord injury. Early cortisol elevation following injury peaked by eight hours and then precipitously dropped to baseline levels before 24 hours following injury.
The hypothesis that pathologic free-radical reactions are initiated and catalyzed in the major central nervous system (CNS) disorders has been further supported by the current acute spinal cord injury work that has demonstrated the appearance of specific, cholesterol free-radical oxidation products. The significance of these products is suggested by the fact that: (i) they increase with time after injury; (ii) their production is curtailed with a steroidal antioxidant; (iii) high antioxidant doses of the steroidal antioxidant which curtail the development of free-radical product prevent tissue degeneration and permit functional restoration. The role of pathologic free-radical reactions is also inferred from the loss of ascorbic acid, a principal CNS antioxidant, and of extractable cholesterol. These losses are also prevented by the steroidal antioxidant. This model system is among others in the CNS which offer distinctive opportunities to study, in vivo, the onset and progression of membrane damaging free-radical reactions within well-defined parameters of time, extent of tissue injury, correlation with changes in membrane enzymes, and correlation with readily measurable in vivo functions.
The purpose of this study was to determine the effect of methylprednisolone sodium succinate on clincal recovery and tissue preservation following compression trauma of feline spinal cord. Cats were anesthetized with pentobarbital and injured by placing a 170-gm weight on the spinal cord for 5 minutes. One hour after injury, the animals were given intravenous steroid (15 mg/kg/day) for 2 days in three devided doses, 15 mg/kg/day for 1 day intramuscularly, 7.5 mg/kg/day intramuscularly for 3 days, and 3.75 mg/kg/day intramuscularly for 3 days, for a total of 9 days. In a control group, the animals were injured but untreated. At 60 days after injury, the animals were sacrifieced by perfusion fixation with 10% formalin. The spinal cord was removed and evaluated for a number of morphometric parameters, including percentage of spinal cord cross-sectional area containing the cavity (%area) and percentage of spinal cord volume occupied by the cavity (%volume). A clinical recovery score (recovery index) was devised to evaluate neurological recovery. Steroid-treated cats showed significantly greater recovery than the untreated controls (p less than 0.001). Moreover, the spinal cord of treated cats displayed greater tissue preservation as measured by %area (p leass than 0.005) and %volume (p less than 0.004). Correlation coefficients comparing the recovery index with morphometric parameters revealed a negative correlation between cavity size and recovery. These data provide evidence for a beneficial effect of methylprednisolone in promoting recovery and preserving spinal cord tissue following blunt injury to the feline spinal cord.
The purpose of this study was to develop a simple, reproducible model for examining the morphologic, physiologic, and biochemical consequences of stretch-induced injury on tissue-cultured cells of brain origin. Rat cortical astrocytes from 1- to 2-day-old rats were cultured to confluency in commercially available 25-mm-diameter tissue culture wells with a 2-mm-thick flexible silastic bottom. A cell injury controller was used to produce a closed system and exert a rapid positive pressure of known amplitude (psi) and duration (msec). The deformation of the membrane, and thus the stretch of the cells growing on the membrane, was proportional to the amplitude and duration of the air pressure pulse. Extent of cell injury was qualitatively assessed by light and electron microscopy and quantitatively assessed by nuclear uptake of the fluorescent dye propidium iodide, which is excluded from cells with intact membranes. Lactate dehydrogenase (LDH) enzyme release was measured spectrophotometrically. Cell injury was found to be proportional to the extent of the silastic membrane deformation. Increasing cell stretch caused mitochondrial swelling and vacuolization as well as disruption of glial filaments. Stretching also caused increased dye uptake, with maximum dye uptake occurring with a 50 msec pressure pulse duration, whereas deformations produced over longer periods of time (seconds) caused little dye uptake. With increasing postinjury survival fewer cells took up dye, implying cell repair. LDH release was also proportional to the amplitude of cell stretch, with maximum release occurring within 2 h of injury. In summary we have developed a simple, reproducible model to produce graded, strain-related injuries in cultured cells. Our continuing experiments suggest that this model can be used to study the biochemistry and physiology of injury as well as serve as a tool to examine the efficacy of therapeutic agents.