Methylprednisolone treatment in acute spinal cord injury: the myth challenged through a structured analysis of published literature

The efficacy of erythropoietin on acute spinal cord injury. An experimental study on a rat model

INTRODUCTION

The accumulated knowledge of erythropoietin (EPO) interaction in neural injury has led to potentially novel therapeutic strategies. Previous experimental studies of recombinant human EPO (rhEPO) administration have shown favorable results after central and peripheral neural injury. In the present study we used the aneurysmal clip model to evaluate the efficacy of two different regimes of rhEPO administration on the functional outcome after severe acute spinal cord injury (ASCI).

MATERIALS AND METHODS

Thirty rats were operated on with posterior laminectomy at thoracic 10th vertebra. Spinal cord trauma produced by extradural placement of the aneurysm clip, for 1 min. Animals were divided into three groups; the first group received a low total EPO dose (EPO-L), (2 doses of 1,000 IU each s.c.). The second group was administered the high total EPO dose (EPO-H), (14 doses of 1,000 IU each s.c.), and the third was the Control group, which received normal saline in the same time fashion with EPO-H group. Follow-up was for 6 weeks. Estimation of the functional progress of each rat was calculated using the locomotor rating scale of Basso et al, with a range from 0 to 21.

RESULTS

After surgery the animals suffered paraplegia with urinary disturbances. Rats that received EPO demonstrated statistically significant functional improvement compared to the Control group, throughout study interval. On the last follow-up at 6 weeks the EPO-L rats achieved a mean score 17.3 +/- 1.15, the EPO-H 14.7 +/- 1.82, and the control group 8.2 +/- 0.78. Comparison between the two EPO groups reveals superior final outcome of the group treated with lower total dose.

CONCLUSION

Our study supports current knowledge, that EPO administration has a positive effect on functional recovery after experimental ASCI. These data reflect the positive impact of EPO on the pathophysiologic cascade of secondary neural damage. However, we observed a dose-related effect on functional recovery. Interestingly, large doses do not seem to favor the neurological recovery as lower doses do.

Adverse events associated with anterior cervical spine surgery

Anterior cervical procedures for neurologic decompression and fusion, including cervical diskectomy and cervical corpectomy, are commonly performed by orthopaedic surgeons and spinal neurosurgeons. These procedures are highly successful in treating most patients with persistent pain and neurologic symptoms that have not responded to nonsurgical methods. Adverse events occur infrequently, but several have been described, including esophageal injury, vertebral artery injury, dural tear, postoperative airway compromise, spinal cord injury, hematoma, dysphagia, dysphonia, and graft dislodgement. Newer procedures, such as cervical total disk replacement and the use of bone morphogenetic protein as a supplement to fusion, have raised unique concerns. Appropriate strategies must be utilized to avoid these adverse events, and the treating surgeon should have an understanding of how to detect and manage such events when they do arise.

Trauma

In terms of cost and years of potential lives lost, injury arguably remains the most important public health problem facing the United States. Care of traumatically injured patients depends on early surgical intervention and avoiding delays in the diagnosis of injuries that threaten life and limb. In the critical care phase, successful outcomes after injury depend almost solely on diligence, attention to detail, and surveillance for iatrogenic infections and complications.

Association of clinical and magnetic resonance imaging findings with outcome in dogs suspected to have ischemic myelopathy: 50 cases (2000-2006)

OBJECTIVE

To determine whether clinical signs or magnetic resonance imaging findings were associated with outcome in dogs with presumptive ischemic myelopathy.

DESIGN

Retrospective case series.

ANIMALS

50 dogs.

PROCEDURES

Medical records and magnetic resonance images were reviewed. A neurologic score from 1 (normal) to 5 (most severe degree of dysfunction) was assigned on the basis of neurologic signs at the time of initial examination. Follow-up information was obtained from the medical records and by means of a telephone questionnaire completed by owners and referring veterinarians.

RESULTS

Median neurologic score at the time of initial examination was 3 (range, 2 to 5). Median follow-up time was 584 days (range, 4 to 2,090 days). Neurologic score at the time of initial examination and extent of the lesion seen on magnetic resonance images (quantified as the lesion length-to-vertebral length ratio and as the percentage cross-sectional area of the lesion) were significantly associated with outcome. Sensitivity of using a lesion length-to-vertebral length ratio > 2.0 or a percentage cross-sectional area of the lesion > or = 67% to predict an unsuccessful outcome was 100%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that severity of neurologic signs at the time of initial examination and extent of the lesions seen on magnetic resonance images were associated with outcome in dogs with ischemic myelopathy.

Advanced trauma life support, 8th edition, the evidence for change

The American College of Surgeons Committee on Trauma's Advanced Trauma Life Support Course is currently taught in 50 countries. The 8th edition has been revised following broad input by the International ATLS subcommittee. Graded levels of evidence were used to evaluate and approve changes to the course content. New materials related to principles of disaster management have been added. ATLS is a common language teaching one safe way of initial trauma assessment and management.

Can the immune system be harnessed to repair the CNS?

Experimental and clinical data have demonstrated that activating the immune system in the CNS can be destructive. However, other studies have shown that enhancing an immune response can be therapeutic, and several clinical trials have been initiated with the aim of boosting immune responses in the CNS of individuals with spinal cord injury, multiple sclerosis and Alzheimer's disease. Here, we evaluate the controversies in the field and discuss the remaining scientific challenges that are associated with enhancing immune function in the CNS to treat neurological diseases.

Kainate and metabolic perturbation mimicking spinal injury differentially contribute to early damage of locomotor networks in the in vitro neonatal rat spinal cord

Acute spinal cord injury evolves rapidly to produce secondary damage even to initially spared areas. The result is loss of locomotion, rarely reversible in man. It is, therefore, important to understand the early pathophysiological processes which affect spinal locomotor networks. Regardless of their etiology, spinal lesions are believed to include combinatorial effects of excitotoxicity and severe stroke-like metabolic perturbations. To clarify the relative contribution by excitotoxicity and toxic metabolites to dysfunction of locomotor networks, spinal reflexes and intrinsic network rhythmicity, we used, as a model, the in vitro thoraco-lumbar spinal cord of the neonatal rat treated (1 h) with either kainate or a pathological medium (containing free radicals and hypoxic/aglycemic conditions), or their combination. After washout, electrophysiological responses were monitored for 24 h and cell damage analyzed histologically. Kainate suppressed fictive locomotion irreversibly, while it reversibly blocked neuronal excitability and intrinsic bursting induced by synaptic inhibition block. This result was associated with significant neuronal loss around the central canal. Combining kainate with the pathological medium evoked extensive, irreversible damage to the spinal cord. The pathological medium alone slowed down fictive locomotion and intrinsic bursting: these oscillatory patterns remained throughout without regaining their control properties. This phenomenon was associated with polysynaptic reflex depression and preferential damage to glial cells, while neurons were comparatively spared. Our model suggests distinct roles of excitotoxicity and metabolic dysfunction in the acute damage of locomotor networks, indicating that different strategies might be necessary to treat the various early components of acute spinal cord lesion.

Case report: Brown-Séquard syndrome resulting from a ski injury in a 7-year-old male

Cervical spine and spinal cord injuries are rare in pediatric trauma victims. The majority result from blunt trauma. Spinal cord injury without radiographic abnormality has been reported to be more common among young children than adults. The Brown-Séquard syndrome is rarely seen as the result of blunt trauma. We present the case of young boy who suffered spinal cord injury without radiographic abnormality resulting in the Brown-Séquard syndrome and review the controversy surrounding the use of high-dose corticosteroids in the treatment of pediatric spinal cord injury. Current data do not support the use of corticosteroids as 'standard of care' for this population.

Methylprednisolone for acute spinal cord injury: 5-year practice reversal

OBJECTIVE

To re-evaluate practice patterns for methylprednisolone (MP) administration in patients with acute spinal cord injury (SCI) within the spinal surgery community across Canada five years after the publication of practice recommendations.

METHODS

Canadian orthopedic and neurological spine surgeons were surveyed at their respective annual meetings about their practice of steroid administration for acute SCI by means of a questionnaire comprised of the same seven questions posed five years ago plus an additional question related to change of view.

RESULTS

Forty-two surgeons and twenty-one residents directly involved in the acute management of SCI completed the questionnaire. Seventy-six percent of spinal surgeons do not prescribe MP for SCI in sharp contrast to 76% who prescribed it five years ago. Of the 24% who use steroids, the NASCIS II dosing regimen is most commonly followed. One third of physicians continue to administer MP because of fear of litigation.

CONCLUSIONS

Over a five year period there has been a complete reversal in practice patterns of MP administration for SCI, along with an increased familiarity of the published literature. Attendance at meetings, participation in local group discussions, and peer-reviewed publications appear effective in altering practice preferences arising from peer pressure and even fear of litigation.

Methylprednisolone protects oligodendrocytes but not neurons after spinal cord injury

Methylprednisolone (MP) is used to treat a variety of neurological disorders involving white matter injury, including multiple sclerosis, acute disseminated encephalomyelitis, and spinal cord injury (SCI). Although its mechanism of action has been attributed to anti-inflammatory or antioxidant properties, we examined the possibility that MP may have direct neuroprotective activities. Neurons and oligodendrocytes treated with AMPA or staurosporine died within 24 h after treatment. MP attenuated oligodendrocyte death in a dose-dependent manner; however, neurons were not rescued by the same doses of MP. This protective effect was reversed by the glucocorticoid receptor (GR) antagonist (11, 17)-11-[4-(dimethylamino)phenyl]-17-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one (RU486) and small interfering RNA directed against GR, suggesting a receptor-dependent mechanism. MP reversed AMPA-induced decreases in the expression of anti-apoptotic Bcl-x(L), caspase-3 activation, and DNA laddering, suggesting anti-apoptotic activity in oligodendrocytes. To examine whether MP demonstrated this selective protection in vivo, neuronal and oligodendrocyte survival was assessed in rats subjected to spinal cord injury (SCI); groups of rats were treated with or without MP in the presence or absence of RU486. Eight days after SCI, MP significantly increased oligodendrocytes (CC-1-immunoreactive cells) after SCI, but neuronal (neuronal-specific nuclear protein-immunoreactive cells) number remained unchanged; RU486 reversed this protective effect. MP also inhibited SCI-induced decreases in Bcl-x(L) and caspase-3 activation. Consistent with these findings, the volume of demyelination, assessed by Luxol fast blue staining, was attenuated by MP and reversed by RU486. These results suggest that MP selectively inhibits oligodendrocyte but not neuronal cell death via a receptor-mediated action and may be a mechanism for its limited protective effect after SCI.

Bite wounds involving the spine: Characteristics, therapy and outcome in seven cases

Medical records of five dogs and two cats with bite wounds to the spine were reviewed. All dogs were bitten in the cervical spine and presented as quadriparetic. Both cats were bitten at the lumbar spine; one was paraparetic and the other paraplegic. Concomitant injuries to structures other than the spine were seen in two cases. Radiographic findings included vertebral fractures in all cases. Medical therapy included antibiotics (7/7), methylprednisolone sodium succinate (4/7) and analgesia (7/7). Five cases underwent minor (4/5) or extensive (1/5) surgical debridement. All cervical fractures were stabilized with fiberglass casts and animals with lumbar injury were cage rested for a month. Six of the cases survived, five of which regained good to excellent ambulatory ability within the first month. Although, the numbers of reported cases are limited, this study shows that adequate surgical debridement and wound drainage combined with external coaptation can be sufficient to manage bite wounds that involve the spine.

Intravenous infusion of dihydroginsenoside Rb1 prevents compressive spinal cord injury and ischemic brain damage through upregulation of VEGF and Bcl-XL

Red ginseng root (Panax Ginseng CA Meyer) has been used clinically by many Asian people for thousands of years without any detrimental effects. One of the major components of Red ginseng root is ginsenoside Rb(1) (gRb1). Previously, we showed that intravenous infusion of gRb1 ameliorated ischemic brain damage through upregulation of an anti-apoptotic factor, Bcl-x(L) and that topical application of gRb1 to burn wound lesion facilitated wound healing through upregulation of vascular endothelial growth factor (VEGF). In the present study, we produced dihydroginsenoside Rb1 (dgRb1), a stable chemical derivative of gRb1, and showed that intravenous infusion of dgRb1 improved spinal cord injury (SCI) as well as ischemic brain damage. As we expected, the effective dose of dgRb1 was ten times lower than that of gRb1. Intravenous infusion of dgRb1 at this effective dose did not affect brain temperature, blood pressure or cerebral blood flow, suggesting that dgRb1 rescued damaged neurons without affecting systemic parameters. In subsequent in vitro studies that focused on dgRb1-induced expression of gene products responsible for neuronal death or survival, we showed that dgRb1 could upregulate the expression of not only Bcl-x(L), but also a potent angiogenic and neurotrophic factor, VEGF. We also showed that dgRb1-induced expression of bcl-x(L) and VEGF mRNA was HRE (hypoxia response element) and STRE (signal transducers and activators of transcription 5 (Stat5) response element) dependent, respectively.

Combination of dexamethasone and etanercept reduces secondary damage in experimental spinal cord trauma

The aim of our study was to evaluate the therapeutic efficacy of combination therapy with etanercept and dexamethasone (DEX) in vivo in experimental murine model of spinal cord trauma, which was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and cytokine production followed by recruitment of other inflammatory cells, production of inflammation mediators, tissue damage, apoptosis and disease. Treatment of the mice with etanercept (1.25 mg/kg) and DEX (0.025 mg/kg) when administered as a combination therapy but not as a single treatment significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) infiltration of neutrophils (MPO evaluation), (3) inducible nitric oxide synthase, nitrotyrosine, and cytokines expression (tumor necrosis factor-alpha and interleukin-1 beta), (4) and apoptosis (Terminal deoxynucleotidyltransferase-mediated UTP end labeling staining, Fas-ligand expression and Bax and Bcl-2 expression). In a separate set of experiments we have also clearly demonstrated that the combination therapy significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate for the first time that strategies targeting multiple proinflammatory pathways may be more effective than a single effector molecule for the treatment of spinal cord trauma.

An overview of tissue engineering approaches for management of spinal cord injuries

Severe spinal cord injury (SCI) leads to devastating neurological deficits and disabilities, which necessitates spending a great deal of health budget for psychological and healthcare problems of these patients and their relatives. This justifies the cost of research into the new modalities for treatment of spinal cord injuries, even in developing countries. Apart from surgical management and nerve grafting, several other approaches have been adopted for management of this condition including pharmacologic and gene therapy, cell therapy, and use of different cell-free or cell-seeded bioscaffolds. In current paper, the recent developments for therapeutic delivery of stem and non-stem cells to the site of injury, and application of cell-free and cell-seeded natural and synthetic scaffolds have been reviewed.

A review of progress in understanding the pathophysiology and treatment of brain edema

Object

Brain edema resulting from traumatic brain injury (TBI) or ischemia if uncontrolled exhausts volume reserve and leads to raised intracranial pressure and brain herniation. The basic types of edema—vasogenic and cytotoxic—were classified 50 years ago, and their definitions remain intact.

Methods

In this paper the author provides a review of progress over the past several decades in understanding the pathophysiology of the edematous process and the success and failures of treatment. Recent progress focused on those manuscripts that were published within the past 5 years.

Results

Perhaps the most exciting new findings that speak to both the control of production and resolution of edema in both trauma and ischemia are the recent studies that have focused on the newly described “water channels” or aquaporins. Other important findings relate to the predominance of cellular edema in TBI.

Conclusions

Significant new findings have been made in understanding the pathophysiology of brain edema; however, less progress has been made in treatment. Aquaporin water channels offer hope for modulating and abating the devastating effects of fulminating brain edema in trauma and stroke.

REVIEW OF TREATMENT TRIALS IN HUMANSPINAL CORD INJURY

OBJECTIVE

To provide a comprehensive review of the treatment trials in the field of spinal cord injury, emphasizing what has been learned about the effectiveness of the agents and strategies tested and the quality of the methodology. The review aims to provide useful information for the improvement of future trials. The review audience includes practitioners, researchers, and consumers.

METHODS

All publications describing organized trials since the 1960s were analyzed in detail, emphasizing randomized, prospective controlled trials and published Phase I and II trials. Trials were categorized into neuroprotection, surgery, regeneration, and rehabilitation trials. Special attention was paid to design, outcome measures, and case selection.

RESULTS

There are 10 randomized prospective control trials in the acute phase that have provided much useful information. Current neurological grading systems are greatly improved, but still have significant shortcomings, and independent, trained, and blinded examiners are mandatory. Other trial designs should be considered, especially those using adaptive randomization. Only methylprednisolone and thyrotropin-releasing hormone have been shown to be effective, but the results of the former are controversial, and studies involving the latter involved too few patients. None of the surgical trials has proven effectiveness. Currently, a multitude of cell-based Phase I trials in several countries are attracting large numbers of patients, but such treatments are unproven in effectiveness and may cause harm. Only a small number are being conducted in a randomized or blinded format. Several consortia have committed to a promise to improve the conduct of trials.

CONCLUSION

A large number of trials in the field of spinal cord injury have been conducted, but with few proven gains for patients. This review reveals several shortcomings in trial design and makes several recommendations for improvement.