Spinal Cord Injury: Emerging Technologies

The mainstay of treatment for spinal cord injury includes decompressive laminectomy and elevation of mean arterial pressure. However, outcomes often remain poor. Extensive research and ongoing clinical trials seek to design new treatment options for spinal cord injury, including stem cell therapy, scaffolds, brain-spine interfaces, exoskeletons, epidural electrical stimulation, ultrasound, and cerebrospinal fluid drainage. Some of these treatments are targeted at the initial acute window of injury, during which secondary damage occurs; others are designed to help patients living with chronic injuries.

Trends in the Use of Corticosteroids in the Management of Acute Spinal Cord Injury in North American Clinical Trials Network Sites

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), which was investigated initially 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 changes with the evolution in published literature and guidelines. Data on patients enrolled from 2008-2018 in the prospective, multi-center NACTN registry, and in whom information related to the use of steroids was available, were analyzed. Patients were stratified based on 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 and genitourinary (GIGU), pulmonary, and dermatological 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 those with 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 with those not receiving steroids (73%, n = 265; p = 0.0003). Compared with patients receiving steroids, however, 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.

A review of regenerative therapy for spinal cord injury using human iPS cells

Spinal cord injury (SCI) has been considered to cause sudden, irreversible loss of function in patients. However, developments in stem cell biology and regenerative medicine are changing this conventional notion. Here we reviewed the overview of regenerative medicine of SCI. As a consequence of the establishment of human induced pluripotent stem cells (hiPSCs), hiPSC-based therapies for SCI, such as neural stem/progenitor cell (NS/PC) transplantation, have emerged as promising therapeutic modalities. Using several animal models, hiPSC-NS/PC transplantation into subacute injured spinal cords has been repeatedly demonstrated to improve locomotor function. Some biological mechanisms underlying this improvement have been proposed. In particular, combined with advanced neuroscience techniques such as designer receptors exclusively activated by designer drugs (DREADDs), neuronal relay theory, in which the transplanted cell-derived neurons reconstruct disrupted neuronal circuits, was proven to be involved histologically, pharmaceutically, electrophysiologically, and via in vivo bioimaging. Based on these findings, hiPSC-NS/PC transplantation for subacute SCI was moved ahead to a clinical study on human patients. At the same time, the search for effective treatments for chronic SCI is proceeding gradually, combining hiPSC-NS/PC transplantation with other treatment modalities such as rehabilitation, pharmaceutical interventions, or optimal scaffolds. In addition to NS/PCs, oligodendrocyte precursor cells (OPCs) are also a promising cell source for transplantation, as demyelinated axons affected by SCI can be repaired by OPCs. Therapies with OPCs derived from hiPSCs are still in preclinical studies but have shown favorable outcomes in animal models. In the future, several therapeutic options may be available according to the pathological conditions and the time period of SCI. Moreover, the application of regenerative therapy for the spinal cord could be broadened to degenerative disorders, such as spinal canal stenosis. Summary sentence: A historical review of human induced pluripotent stem cell (hiPSC) based cell transplantation therapy for spinal cord injury (SCI), in particular about footsteps of hiPSC-derived neural stem/progenitor cell transplantation, recent clinical study, and its future perspective.

Selective Calpain Inhibition Improves Functional and Histopathological Outcomes in a Canine Spinal Cord Injury Model

Calpain activation has been implicated in various pathologies, including neurodegeneration. Thus, calpain inhibition could effectively prevent spinal cord injury (SCI) associated with neurodegeneration. In the current study, a dog SCI model was used to evaluate the therapeutic potential of a selective calpain inhibitor (PD150606) in combination with methylprednisolone sodium succinate (MPSS) as an anti-inflammatory drug. SCI was experimentally induced in sixteen mongrel dogs through an epidural balloon compression technique. The dogs were allocated randomly into four groups: control, MPSS, PD150606, and MPSS+PD150606. Clinical evaluation, serum biochemical, somatosensory evoked potentials, histopathological, and immunoblotting analyses were performed to assess treated dogs during the study. The current findings revealed that the combined administration of MPSS+PD150606 demonstrated considerably lower neuronal loss and microglial cell infiltration than the other groups, with a significant improvement in the locomotor score. The increased levels of inflammatory markers (GFAP and CD11) and calcium-binding proteins (Iba1 and S100) were significantly reduced in the combination group and to a lesser extent in MPSS or PD150606 treatment alone. Interestingly, the combined treatment effectively inhibited the calpain-induced cleavage of p35, limited cdk5 activation, and inhibited tau phosphorylation. These results suggest that early MPSS+PD150606 therapy after acute SCI may prevent subsequent neurodegeneration via calpain inhibition.

Tratamento das lesões agudas da medula espinal: Uma pesquisa entre cirurgiões de coluna iberoamericanos – Parte 1: Uso de corticosteroides em altas doses

Objetivo O objetivo do presente estudo foi avaliar a prática atual de uso do succinato sódico de metilprednisolona (MPSS, na sigla em inglês) nas lesões agudas da medula espinal (LAMEs) entre cirurgiões de coluna de países ibero-americanos.

Métodos Um estudo transversal descritivo foi realizado. O questionário continha duas seções, uma sobre os dados demográficos dos cirurgiões e acerca da administração de MPSS, e foi enviado por correio eletrônico aos membros da Sociedad Ibero Latinoamericana de Columna (SILACO, na sigla em espanhol) e sociedades associadas.

Resultados No total, 182 cirurgiões participaram do estudo: 65,4% (119) eram cirurgiões ortopédicos e 24,6% (63), neurocirurgiões. Sessenta e nove (37,9%) usaram MPSS no tratamento inicial da LAME. Não houve diferenças significativas entre países (p = 0,451), especialidades (p = 0,352) ou senioridade do cirurgião (p = 0,652) em relação ao uso de corticosteroides no tratamento inicial da LAME. Destes, 45 (65,2%) relataram a administração de um bolus de alta dose (30 mg/kg) seguido por perfusão (5,4 mg/kg/h). Quarenta e seis (66,7%) dos cirurgiões que usam MPSS apenas o prescrevem a pacientes tratados nas primeiras 8 horas após a LAME. A maioria dos cirurgiões (50,7% [35]) administrou corticosteroides em alta dose devido à convicção de seus benefícios clínicos e melhora da recuperação neurológica.

Conclusão Os resultados do presente questionário mostram que o uso de MPSS na LAME não está disseminado entre os cirurgiões de coluna e que a controvérsia sobre sua administração ainda não foi resolvida. É provável que isto se deva ao baixo nível de evidência dos dados existentes, a variações ao longo dos anos, a inconsistências nos protocolos terapêuticos agudo e a diferentes sistemas de saúde.

The Immunological Roles of Olfactory Ensheathing Cells in the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating type of neurological disorder of the central nervous system (CNS) with high mortality and disability. The pathological processes of SCI can usually be described as two stages, namely, primary and acute secondary injuries. Secondary injury produces more significant exacerbations of the initial injury. Among all the mechanisms of secondary damage, infection and inflammatory responses, as the principle culprits in initiating the second phase of SCI, can greatly contribute to the severity of SCI and numerous sequelae after SCI. Therefore, effectively antagonizing pro-inflammatory responses may be a promising treatment strategy to facilitate functional recovery after SCI. Olfactory ensheathing cells (OECs), a unique type of glial cells, have increasingly become potential candidates for cell-based therapy in the injured CNS. Strikingly, there is growing evidence that the mechanisms underlying the anti-inflammatory role of OECs are associated with the immune properties and secretory functions of these cells responsible for anti-neuroinflammation and immunoregulatory effects, leading to maintenance of the internal microenvironment. Accordingly, a more profound understanding of the mechanism of OEC immunological functions in the treatment of SCI would be beneficial to improve the therapeutic clinical applications of OECs for SCI. In this review, we mainly summarize recent research on the cellular and molecular immune attributes of OECs. The unique biological functions of these cells in promoting neural regeneration are discussed in relation of the development of novel therapies for CNS injury.

3D Bioprinting for Spinal Cord Injury Repair

Spinal cord injury (SCI) is considered to be one of the most challenging central nervous system injuries. The poor regeneration of nerve cells and the formation of scar tissue after injury make it difficult to recover the function of the nervous system. With the development of tissue engineering, three-dimensional (3D) bioprinting has attracted extensive attention because it can accurately print complex structures. At the same time, the technology of blending and printing cells and related cytokines has gradually been matured. Using this technology, complex biological scaffolds with accurate cell localization can be manufactured. Therefore, this technology has a certain potential in the repair of the nervous system, especially the spinal cord. So far, this review focuses on the progress of tissue engineering of the spinal cord, landmark 3D bioprinting methods, and landmark 3D bioprinting applications of the spinal cord in recent years.

Potential of different cells-derived exosomal microRNA cargos for treating spinal cord injury

Spinal cord injury (SCI) is a disastrous situation that affects many patients worldwide. A profound understanding of the pathology and etiology of SCI is of great importance in inspiring new therapeutic concepts and treatment. In recent years, exosomes, which are complex lipid membrane structures secreted nearly by all kinds of plants and animal cells, can transport their valuable cargoes (e.g., proteins, lipids, RNAs) to the targeted cells and exert their communication and regulation functions, which open up a new field of treatment of SCI. Notably, the exosome's advantage is transporting the carried material to the target cells across the blood-brain barrier and exerting regulatory functions. Among the cargoes of exosomes, microRNAs, through the modulation of their mRNA targets, emerges with great potentiality in the pathological process, diagnosis and treatment of SCI. In this review, we discuss the role of miRNAs transported by different cell-derived exosomes in SCI that are poised to enhance SCI-specific therapeutic capabilities of exosomes.

Ecto-5'-nucleotidase (CD73) inhibits dorsal root ganglion neuronal apoptosis by promoting the Ado/cAMP/PKA/CREB pathway

Spinal cord injury (SCI) is a serious affliction that can lead to insufficient blood supply to the spinal cord, resulting in nutrient and energy deficiency in nerve cells such as neurons. In the present study, a spinal cord injury mouse model was constructed using wild-type (WT) and ecto-5'-nucleotidase (CD73)^-/- mice. The results of TUNEL and immunofluorescence assays indicated that the apoptosis of neurons in CD73^-/- mice was increased after spinal cord injury. Dorsal root ganglion (DRG) neurons from WT and CD73^-/- mice were cultured in low glucose and hypoxic conditions to simulate the effects of spinal cord injury on neurons. Subsequently, a western blot assay was used to detect the expression of CD73, caspase-3 and Bcl-2. Flow cytometry was used to detect cell apoptosis and the corresponding kits were used to detect changes in lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), reactive oxygen species (ROS), adenosine triphosphate (ATP) and cell activity. The results revealed that the apoptosis level of CD73-overexpressing DRG neurons was decreased under anoxia and glucose deficiency. The release of LDH, MDA and the production of ROS in CD73 DRG neurons was decreased, while the synthesis of ATP, the activity of SOD and cell activity increased after hypoxia-hypoglycemia treatment. Additional cellular studies demonstrated that blocking the expression and hydrolase activity of CD73 with α,β-methylene ADP (APCP) could counteract the protective effect of CD73 on neuronal apoptosis, while adenosine (Ado) could rescue the increased apoptosis caused by CD73 deletion. In addition, the cAMP/ protein kinase A (PKA)/cAMP response element-binding protein (CREB) signaling pathway was also positively regulated by CD73 and Ado. In conclusion, CD73 could inhibit DRG neuronal apoptosis by promoting the Ado/cAMP/PKA/CREB pathway.

Elucidating the Pivotal Neuroimmunomodulation of Stem Cells in Spinal Cord Injury Repair

Spinal cord injury (SCI) is a distressing incident with abrupt onset of the motor as well as sensory dysfunction, and most often, the injury occurs as result of high-energy or velocity accidents as well as contact sports and falls in the elderly. The key challenges associated with nerve repair are the lack of self-repair as well as neurotrophic factors and primary and secondary neuronal apoptosis, as well as factors that prevent the regeneration of axons locally. Neurons that survive the initial traumatic damage may be lost due to pathogenic activities like neuroinflammation and apoptosis. Implanted stem cells are capable of differentiating into neural cells that replace injured cells as well as offer local neurotrophic factors that aid neuroprotection, immunomodulation, axonal sprouting, axonal regeneration, and remyelination. At the microenvironment of SCI, stem cells are capable of producing growth factors like brain-derived neurotrophic factor and nerve growth factor which triggers neuronal survival as well as axonal regrowth. Although stem cells have proven to be of therapeutic value in SCI, the major disadvantage of some of the cell types is the risk for tumorigenicity due to the contamination of undifferentiated cells prior to transplantation. Local administration of stem cells via either direct cellular injection into the spinal cord parenchyma or intrathecal administration into the subarachnoid space is currently the best transplantation modality for stem cells during SCI.

Sirtuins: Potential Therapeutic Targets for Defense against Oxidative Stress in Spinal Cord Injury

Spinal cord injury (SCI) is one of the most incapacitating neurological disorders. It involves complex pathological processes that include a primary injury and a secondary injury phase, or a delayed stage, which follows the primary injury and contributes to the aggravation of the SCI pathology. Oxidative stress, a key pathophysiological event after SCI, contributes to a cascade of inflammation, excitotoxicity, neuronal and glial apoptosis, and other processes during the secondary injury phase. In recent years, increasing evidence has demonstrated that sirtuins are protective toward the pathological process of SCI through a variety of antioxidant mechanisms. Notably, strategies that modulate the expression of sirtuins exert beneficial effects in cellular and animal models of SCI. Given the significance and novelty of sirtuins, we summarize the oxidative stress processes that occur in SCI and discuss the antioxidant effects of sirtuins in SCI. We also highlight the potential of targeting sirtuins for the treatment of SCI.

Assessment of the Oral Delivery of a Myelin Basic Protein Gene Promoter with Antiapoptotic bcl-xL (pMBP-bcl-xL) DNA by Cyclic Peptide Nanotubes with Two Aspect Ratios and Its Biodistribution in the Brain and Spinal Cord

Cyclo-(D-Trp-Tyr) peptide nanotubes (PNTs) were reported to be potential carriers for oral gene delivery in our previous study; however, the effect of the aspect ratio (AR) of these PNTs on gene delivery in vivo could affect penetration or interception in biological environments. The aim of this study was to assess the feasibility of cyclo-(D-Trp-Tyr) PNTs with two ARs as carriers for oral pMBP-bcl-x_L-hRluc delivery to the spinal cord to treat spinal cord injury (SCI). We evaluated the biodistribution of oligodendrocyte (OLG)-specific myelin basic protein gene promoter-driven antiapoptotic DNA (pMBP-bcl-x_L) to the brain and spinal cord delivered with cyclo-(D-Trp-Tyr) PNTs with large (L) and small (S) PNTs with two ARs. After complex formation, the length, width, and AR of the L-PNTs/DNA were 77.86 ± 3.30, 6.51 ± 0.28, and 13.75 ± 7.29 μm, respectively, and the length and width of the S-PNTs/DNA were 1.17 ± 0.52 and 0.17 ± 0.05 μm, respectively, giving an AR of 7.12 ± 3.17 as detected by scanning electron microscopy. Each of these three parameters exhibited significant differences (p < 0.05) between L-PNTs/DNA and S-PNTs/DNA. However, there were no significant differences (p > 0.05) between the L-PNTs and S-PNTs for either their DNA encapsulation efficiency (29.72 ± 14.19 and 34.31 ± 16.78%, respectively) or loading efficiency (5.15 ± 2.58 and 5.95 ± 2.91%). The results of the in vitro analysis showed that the S-PNT/DNA complexes had a significantly higher DNA release rate and DNA permeation in the duodenum than the L-PNT/DNA complexes. Using Cy5 and TM-rhodamine to individually and chemically conjugate the PNTs with plasmid DNA, we observed, using laser confocal microscopy, that the PNTs and DNA colocalized in complexes. We further confirmed the complexation between DNA and the PNTs using fluorescence resonance energy transfer (FRET). Data from an in vivo imaging system (IVIS) showed that there was no significant difference (p > 0.05) in PNT distribution between L-PNTs/DNA and S-PNTs/DNA within 4 h. However, the S-PNT/DNA group had a significantly higher DNA distribution (p < 0.05) in several organs, including the ilium, heart, lungs, spleen, kidneys, testes, brain, and spinal cord. Finally, we determined the bcl-x_L protein expression levels in the brain and spinal cord regions for the L-PNT/DNA and S-PNT/DNA complex formulations. These results suggested that either L-PNTs or S-PNTs may be used as potential carriers for oral gene delivery to treat SCI.

Direct Injection of Hydrogels Embedding Gold Nanoparticles for Local Therapy after Spinal Cord Injury

In this study, we created a hydrogel composed of glycol chitosan (gC) and oxidized hyaluronate (oHA). Gold nanoparticles (GNPs) were conjugated with ursodeoxycholic acid (UDCA). The GNP-UDCA complex was embedded into gC-oHA (CHA) hydrogels to form a CHA-GNP-UDCA gel. This CHA-GNP-UDCA gel was injected once into an epicenter of an injured region in SCI rats. Near-infrared (NIR) irradiation was then applied to the lesion as a means of local therapy. To optimize the viscosity for injection into a lesion, several volume ratios of gC and oHA were investigated using scanning electron microscopy and a rotating rheometer. The optimally synthesized CHA-GNP-UDCA gel under NIR irradiation suppressed the production of inflammatory cytokines in vitro. In addition, the optimized CHA-GNP-UDCA gel under NIR irradiation inhibited the cystic cavity of the lesion and significantly improved the hindlimb function. The production of inflammatory cytokines following SCI was significantly inhibited in the CHA-GNP-UDCA gel + NIR group. CHA-GNP-UDCA gels with NIR irradiation can therefore have therapeutic effects for those with spinal cord injuries.

Comparison of systemic and localized carrier-mediated delivery of methylprednisolone succinate for treatment of acute spinal cord injury

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.

Clinical efficacy of γ-globulin combined with dexamethasone and methylprednisolone, respectively, in the treatment of acute transverse myelitis and its effects on immune function and quality of life

Effects of γ-globulin combined with dexamethasone or methylprednisolone in the treatment of acute transverse myelitis (ATM) were investigated. A retrospective analysis of medical records from 136 ATM patients admitted to Linzi District People's Hospital from July 2014 to September 2017 was performed. Patients treated with dexamethasone combined with γ-globulin were in group A (66 cases), and patients treated with methylprednisolone combined with γ-globulin were in group B (70 cases). Clinical efficacy, recovery time of bone marrow function and incidence rate of adverse reactions were analyzed and compared between the two groups. T-lymphocyte subsets in peripheral blood of both groups were detected by Flow cytometry. Quality of life of patients was assessed by the Quality of Life Scale (SF-36) developed by the American Institute of Medicine. Time of sensory recovery, self-walking, improving muscle strength at two levels and urination recovery after treatment in group B were significantly shorter than those in group A (P<0.001); effective rate of treatment in group B was significantly higher than that in group A (P<0.05); incidence rate of adverse reactions in group B was significantly lower than that in group A (P<0.05); ratios of CD3⁺, CD4⁺, CD8⁺ cells and CD4⁺/CD8⁺ in peripheral blood of group A and group B after treatment were significantly higher than those before treatment (P<0.05); scores of general health (GH), physical function (PF), role physical (RP), body pain (BP), social function (SF), role emotional (RE), mental health (MH) and vitality (VT) in group B after treatment were significantly higher than those in group A (P<0.05). In conclusion, clinical efficacy of γ-globulin combined with methylprednisolone in the treatment of ATM patients shows definitely fewer adverse reactions, which can improve their immune function and quality of life.

Phase I/II Study of Intrathecal Administration of Recombinant Human Hepatocyte Growth Factor in Patients with Acute Spinal Cord Injury: A Double-Blind, Randomized Clinical Trial of Safety and Efficacy

Spinal cord injury (SCI) is an abrupt traumatic injury that leads to permanent functional loss, and no practical treatment is available. We have developed pharmaceutical recombinant human hepatocyte growth factor (KP-100), and its efficacy for SCI has been verified using animal models. The purpose of this study was to evaluate the safety and efficacy of intrathecal KP-100 administration for SCI patients in the acute phase. This investigation was a multi-center, randomized, double-blind study. Subjects with modified Frankel grade A/B1/B2 at 72 h after SCI were included. KP-100 was administered intrathecally. Subjects were followed up for 168 days after the first administration. Outcomes were evaluated using American Spinal Injury Association (ASIA) scores and subjected to analysis of covariance. Our results demonstrated that the subjects did not show any serious adverse events caused by KP-100. Forty-three subjects underwent neurological function testing (26 in KP-100 group; 17 in placebo group), which revealed that KP-100 contributed to motor improvement at Days 140 (p = 0.050) and 168 (p = 0.079). In the subset of subjects with Frankel grade A, the proportions of subjects who gained at least 1 point on their lower-extremity motor scores were 33.3% (5/15) and 6.3% (1/16) in the KP-100 and placebo groups, respectively (p = 0.083). Therefore, KP-100 has the potential to be useful and beneficial for SCI patients during the acute phase. However, this was a phase I/II trial and did not definitely address the question of efficacy; a larger phase III trial would be required to assess the efficacy.

Risk factors associated with progressive myelomalacia in dogs with complete sensorimotor loss following intervertebral disc extrusion: a retrospective case-control study

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.

Cell therapy for spinal cord injury using induced pluripotent stem cells

For the past few decades, spinal cord injury (SCI) has been believed to be an incurable traumatic condition, but with recent developments in stem cell biology, the field of regenerative medicine has gained hopeful momentum in the development of a treatment for this challenging pathology. Among the treatment candidates, transplantation of neural precursor cells has gained remarkable attention as a reasonable therapeutic intervention to replace the damaged central nervous system cells and promote functional recovery. Here, we highlight transplantation therapy techniques using induced pluripotent stem cells to treat SCI and review the recent research giving consideration to future clinical applications.

Application of Hepatocyte Growth Factor for Acute Spinal Cord Injury: The Road from Basic Studies to Human Treatment

Hepatocyte growth factor (HGF) was first identified as a potent mitogen for mature hepatocytes, and has also gained attention as a strong neurotrophic factor in the central nervous system. We found that during the acute phase of spinal cord injury (SCI) in rats, c-Met, the specific receptor for HGF, increases sharply, while the endogenous HGF up-regulation is relatively weak. Introducing exogenous HGF into the spinal cord by injecting an HGF-expressing viral vector significantly increased the neuron and oligodendrocyte survival, angiogenesis, and axonal regeneration, to reduce the area of damage and to promote functional recovery in rats after SCI. Other recent studies in rodents have shown that exogenously administered HGF during the acute phase of SCI reduces astrocyte activation to decrease glial scar formation, and exerts anti-inflammatory effects to reduce leukocyte infiltration. We also reported that the intrathecal infusion of recombinant human HGF (intrathecal rhHGF) improves neurological hand function after cervical contusive SCI in the common marmoset, a non-human primate. Based on these collective results, we conducted a phase I/II clinical trial of intrathecal rhHGF for patients with acute cervical SCI who showed a modified Frankel grade of A/B1/B2 72 h after injury onset, from June 2014 to May 2018.

Treatment of Injuries to the Subaxial Cervical Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

STUDY DESIGN

Expert consensus.

OBJECTIVES

To establish treatment recommendations for subaxial cervical spine injuries based on current literature and the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma.

METHODS

This recommendation summarizes the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma.

RESULTS

Therapeutic goals are a stable, painless cervical spine and protection against secondary neurologic damage while retaining maximum possible motion and spinal profile. The AOSpine classification for subaxial cervical injuries is recommended. The Canadian C-Spine Rule is recommended to decide on the need for imaging. Computed tomography is the favoured modality. Conventional x-ray is preserved for cases lacking a "dangerous mechanism of injury." Magnetic resonance imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and to exclude disco-ligamentous injuries. Computed tomography angiography is recommended in high-grade facet joint injuries or in the presence of vertebra-basilar symptoms. A0-, A1- and A2-injuries are treated conservatively, but have to be monitored for progressive kyphosis. A3 injuries are operated in the majority of cases. A4- and B- and C-type injuries are treated surgically. Most injuries can be treated with anterior plate stabilization and interbody support; A4 fractures need vertebral body replacement. In certain cases, additive or pure posterior instrumentation is needed. Usually, lateral mass screws suffice. A navigation system is advised for pedicle screws from C3 to C6.

CONCLUSIONS

These recommendations provide a framework for the treatment of subaxial cervical spine Injuries. They give advice about diagnostic measures and the therapeutic strategy.

iPSC-derived neural precursor cells: potential for cell transplantation therapy in spinal cord injury

A number of studies have demonstrated that transplantation of neural precursor cells (NPCs) promotes functional recovery after spinal cord injury (SCI). However, the NPCs had been mostly harvested from embryonic stem cells or fetal tissue, raising the ethical concern. Yamanaka and his colleagues established induced pluripotent stem cells (iPSCs) which could be generated from somatic cells, and this innovative development has made rapid progression in the field of SCI regeneration. We and other groups succeeded in producing NPCs from iPSCs, and demonstrated beneficial effects after transplantation for animal models of SCI. In particular, efficacy of human iPSC-NPCs in non-human primate SCI models fostered momentum of clinical application for SCI patients. At the same time, however, artificial induction methods in iPSC technology created alternative issues including genetic and epigenetic abnormalities, and tumorigenicity after transplantation. To overcome these problems, it is critically important to select origins of somatic cells, use integration-free system during transfection of reprogramming factors, and thoroughly investigate the characteristics of iPSC-NPCs with respect to quality management. Moreover, since most of the previous studies have focused on subacute phase of SCI, establishment of effective NPC transplantation should be evaluated for chronic phase hereafter. Our group is currently preparing clinical-grade human iPSC-NPCs, and will move forward toward clinical study for subacute SCI patients soon in the near future.

Therapeutic potential of flavonoids in spinal cord injury

Spinal cord injury (SCI) is a catastrophic event that can profoundly affect a patient's life, with far-reaching social and economic effects. A consequential sequence of SCI is the significant neurological or psychological deficit, which obviously contributes to the overall burden of this condition. To date, there is no effective treatment for SCI. Therefore, developing novel therapeutic strategies for SCI is highly prioritized. Flavonoids, one of the most numerous and ubiquitous groups of plant metabolites, are the active ingredients of traditional Chinese medicine such as Scutellaria baicalensis Georgi (Huang Qin) or Ginkgo biloba (Ying Xin). Accumulated research data show that flavonoids possess a range of key pharmacological properties such as anti-inflammatory, anti-oxidant, anti-tumor, anti-viral, anti-cardiovascular disease, immunomodulatory, and neuroprotective effects. Based on this, the flavonoids show therapeutic potential for SCI diseases. In this paper, we will review the pharmacological properties of different types of flavonoids for the treatment of SCI diseases, and potential underlying biochemical mechanisms of action will also be described.

An upper cervical cord compression secondary to occult follicular thyroid carcinoma metastases successfully treated with multiple radioiodine therapies: A clinical case report

RATIONALE

The spine is the most common site of bone metastases due to thyroid cancer; however, spinal cord compression as a complication of metastatic thyroid cancer is very rare.

PATIENT CONCERNS

A 48-year-old female patient was presented to the Neurosurgical Department, complaining of progressive back neck pain with bilateral upper extremities numbness and weakness for 4 months.

DIAGNOSIS

Imaging studies revealed osteolytic destruction in bodies and accessories of the second and third cervical vertebrae with a huge soft-tissue mass compressing spinal cord and causing swelling. After the neurosurgical decompression surgery, the pathological examination established a metastatic follicular carcinoma originating from the thyroid gland.

INTERVENTIONS

Her cervical spinal metastases were hardly removed by surgery and the risks of external beam radiation therapy (EBRT) were very high. So she underwent a total thyroidectomy and received multiple radioiodine (RAI) and concomitant glucocorticoid therapies postoperatively. Radioiodine whole-body scan (WBS) showed multiple abnormal radioiodine uptakes. Then single-photon emission tomography/computed tomography (SPECT/CT) located these spinal metastases involving cervical, lumbar, and sacral vertebrae.

OUTCOMES

After 5 times RAI therapy, her thyroglobulin obviously decreased, with the cervical lesion shrinkage and no spinal cord edema.

LESSONS

RAI therapy and concomitant glucocorticoid therapy could be used for spinal metastases of FTC, even with spinal cord compression.

Efficacy and Safety of Methylprednisolone Sodium Succinate in Acute Spinal Cord Injury: A Systematic Review

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.

A Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on the Use of Methylprednisolone Sodium Succinate

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.

Current Options for Cell Therapy in Spinal Cord Injury

Spinal cord injury (SCI) is a complex pathology that evolves after primary acute mechanical injury, causing further damage to the spinal cord tissue that exacerbates clinical outcomes. Based on encouraging results from preclinical experiments, some cell treatments being translated into clinical practice demonstrate promising and effective improvement in sensory/motor function. Combinatorial treatments of cell and drug/biological factors have been demonstrated to be more effective than cell treatments alone. Recent advances have led to the development of biomaterials aiming to promote in situ cell delivery for SCI, together with combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative cell treatments as well as potential delivery options to treat SCI.

"Direct vision" operation of posterior atlantoaxial transpedicular screw fixation for unstable atlantoaxial fractures: A retrospective study

BACKGROUND

The posterior screw fixation in atlas via posterior arch and lateral mass, also called C1 "pedicle" screw, combined with C2 pedicle screw fixiation has shown better biomechanical stability in unstable atlantoaxial fractures. However, its popularization has to fulfill the limitation imposed by anatomical characteristics. The aim of this study was to explore the manipulation, effect, and safety of the atlantoaxial transpedicular screw fixation under "direct vision" for the treatment of unstable atlantoaxial fracture.

METHODS

All the patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014 were reviewed. Only these patients that were diagnosed with atlantoaxial unstability secondary to trauma and were treated with atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft were included. The safety of transpedicular screw placement, postoperative outcome, atlantoaxial stability, autograft fusion, and complications was observed and analyzed retrospectively. The pain visual analog scale (VAS) and the Japanese Orthopedic Association (JOA) score were used as surgical curative effect evaluation standards.

RESULTS

We reviewed a total of 92 patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014, and 87 patients were treated with atlantoaxial transpedicular screw fixation under "direct vision" and were included this analysis. A total of 306 transpedicular screws in atlas and axis were placed successfully. All cases were followed-up >12 months. The overall breach rate was 11.36%. None of the breaches resulted in new-onset neurological sequela. The neurological status in cases with bilateral upper extremities numbness and lower extremities weakness had improved after surgery. At the latest follow-up, the neck VAS and JOA scores were significantly improved (P < .01) than those preoperatively. No cases demonstrated implantation failure and bone graft absorption on the postoperative x-ray films and CT scans.

CONCLUSION

Atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft for the treatment of unstable atlantoaxial fracture has shown simple manipulation and efficient performance. Thus, the technique of C1-C2 fixation is feasible in treating unstable atlantoaxial fracture.

A causal relationship between the neurotherapeutic effects of miR182/7a and decreased expression of PRDM5

BACKGROUND

Spinal cord injury (SCI) is terrible damage resulting in the deficiencies and necrosis of neurology and causes infinite inconvenience to sufferers. The therapy of SCI still meets a larger number of problems. Therefore, the underlying mechanism and novel therapy of acute SCI (ASCI) are urgent to explore.

MATERIALS AND METHODS

The SCI model was established in rats. The expression of miR-182/miR-7a and PRDM5 at mRNA level was detected by quantitative real-time PCR and the protein expression of PRDM5 and c-caspase 3 was assessed by western blotting assays. The apoptosis of spinal cord neurons (SCN) was assessed on flow cytometry. The transfection of cells was performed by Lipofectamine 2000 kit. The relationship between PRDM5 and miR-182/miR-7a was examined by Luciferase assay.

RESULTS

The expression of PRDM5 was up-regulated at either mRNA (2.212 folds) or protein level after SCI in rats, and knockdown of PRDM5 in SCN declined the c-caspase3 expression. In addition, the expression of miR-182 and miR-7a was decreased by 44.6% and 39.3% after SCI in rats. Moreover, the expression of miR-182 and miR-7a were negatively correlated with the level of PRDM5 expression, and the expression of PRDM5 was inhibited due to the increase of miR-182 and/or miR-7a expression. Moreover, both miR-182 and miR-7a could regulate PRDM5 to control SCN apoptosis. According to the BBB score increased 2 folds, the intrathecal injection of miR-182 and miR-7a improved the neurological function of rats.

CONCLUSION

Inhibition of PRDM5 which was apparently negative correlation with miR-182 and miR-7a could suppress the neurons apoptosis to attenuate acute spinal cord injury in rats.

Puerperal ventral epidural hematoma after epidural labor analgesia

Serious complications in obstetric anesthesia are a rare occurrence. High neuraxial block, respiratory arrest in labor and delivery, and an unrecognized spinal catheter are among the most frequently reported serious complications. A serious complication occurs in approximately 1:3000 obstetric patients. Neuraxial hematoma after obstetric epidural analgesia or anesthesia is extremely rare. We present a case of a puerperal spinal epidural hematoma following epidural labor analgesia. The patient presented with foot drop, which resolved after conservative treatment. We reviewed the epidemiology, clinical manifestations and treatment options for this rare complication.

Traumatic spinal cord injury

Traumatic spinal cord injury (SCI) has devastating consequences for the physical, social and vocational well-being of patients. The demographic of SCIs is shifting such that an increasing proportion of older individuals are being affected. Pathophysiologically, the initial mechanical trauma (the primary injury) permeabilizes neurons and glia and initiates a secondary injury cascade that leads to progressive cell death and spinal cord damage over the subsequent weeks. Over time, the lesion remodels and is composed of cystic cavitations and a glial scar, both of which potently inhibit regeneration. Several animal models and complementary behavioural tests of SCI have been developed to mimic this pathological process and form the basis for the development of preclinical and translational neuroprotective and neuroregenerative strategies. Diagnosis requires a thorough patient history, standardized neurological physical examination and radiographic imaging of the spinal cord. Following diagnosis, several interventions need to be rapidly applied, including haemodynamic monitoring in the intensive care unit, early surgical decompression, blood pressure augmentation and, potentially, the administration of methylprednisolone. Managing the complications of SCI, such as bowel and bladder dysfunction, the formation of pressure sores and infections, is key to address all facets of the patient's injury experience.

The regulatory effect of electro-acupuncture on the expression of NMDA receptors in a SCI rat model

BACKGROUND

In early spinal cord injury (SCI), glutamate receptors, including N-methyl-d-aspartate (NMDA) receptors (NMDARs), are over-stimulated by excessively released glutamate. The enhanced activity of NMDARs may cause cell death by overloading calcium (Ca²⁺) into cells based on their high permeability to Ca²⁺. Studies in SCI animals have shown that treatment with electro-acupuncture (EA) is able to reduce cell death and to improve functional recovery. One possible mechanism of this neuroprotective effect is that EA has regulatory effect on NMDARs.

AIMS

To test whether EA could protect the spinal cord after SCI by decreasing the expression levels of NR1 and NR2A.

MAIN METHODS

We conducted EA treatment on a rat SCI model produced with a New York University (NYU) Impactor and measured hindlimb locomotor function by Basso, Beattie and Bresnahan Locomotor Rating Scale (BBB Scale). The expression of NR1 and NR2, the subunits of NMDARs, in the injured spinal cord was measured by Immunofluorescence stainings, western blot and real-time quantitative PCR (RT-qPCR).

KEY FINDING

Our results showed that two days after the SCI the expression of NR1 and NR2 were dramatically enhanced at both protein and mNRA levels, which were significantly reduced by EA treatment at two specific acupoints, Dazhui (DU14) and Mingmen (DU4).

SIGNIFICANCE

EA is a potential therapeutic method for treating early SCI in human.

Applications of induced pluripotent stem cell technologies in spinal cord injury

Numerous basic research studies have suggested the potential efficacy of neural precursor cell (NPC) transplantation in spinal cord injury (SCI). However, in most such studies, the origin of the cells used was mainly fetal tissue or embryonic stem cells, both of which carry potential ethical concerns with respect to clinical use. The development of induced pluripotent stem cells (iPSCs) opened a new path toward regenerative medicine for SCI. iPSCs can be generated from somatic cells by induction of transcription factors, and induced to differentiate into NPCs with characteristics of cells of the central nervous system. The beneficial effect of iPSC-derived NPC transplantation has been reported from our group and others working in rodent and non-human primate models. These promising results facilitate the application of iPSCs for clinical applications in SCI patients. However, iPSCs also have issues, such as genetic/epigenetic abnormalities and tumorigenesis because of the artificial induction method, that must be addressed prior to clinical use. The selection of somatic cells, generation of integration-free iPSCs, and characterization of differentiated NPCs with thorough quality management are all needed to address these potential risks. To enhance the efficacy of the transplanted iPSC-NPCs, especially at chronic phase of SCI, administration of a chondroitinase or semaphorin3A inhibitor represents a potentially important means of promoting axonal regeneration through the lesion site. The combined use of rehabilitation with such cell therapy approaches is also important, as repetitive training enhances neurite outgrowth of transplanted cells and strengthens neural circuits at central pattern generators. Our group has already evaluated clinical grade iPSC-derived NPCs, and we look forward to initiating clinical testing as the next step toward determining whether this approach is safe and effective for clinical use. This article is part of the mini review series "60th Anniversary of the Japanese Society for Neurochemistry".

Methylprednisolone for acute spinal cord injury: an increasingly philosophical debate

Following publication of NASCIS II, methylprednisolone sodium succinate (MPSS) was hailed as a breakthrough for patients with acute spinal cord injury (SCI). MPSS use for SCI has since become very controversial and it is our opinion that additional evidence is unlikely to break the stalemate amongst clinicians. Patient opinion has the potential to break this stalemate and we review our recent findings which reported that spinal cord injured patients informed of the risks and benefits of MPSS reported a preference for MPSS administration. We discuss the implications of the current MPSS debate on translational research and seek to address some misconceptions which have evolved. As science has failed to resolve the MPSS debate we argue that the debate is an increasingly philosophical one. We question whether SCI might be viewed as a serious condition like cancer where serious side effects of therapeutics are tolerated even when benefits may be small. We also draw attention to the similarity between the side effects of MPSS and isotretinoin which is prescribed for the cosmetic disorder acne vulgaris. Ultimately we question how patient autonomy should be weighed in the context of current SCI guidelines and MPSS's status as a historical standard of care.

MicroRNA-9 controls apoptosis of neurons by targeting monocyte chemotactic protein-induced protein 1 expression in rat acute spinal cord injury model

OBJECTIVE

For the purpose of an early identification of intervention targets for acute spinal cord injury (ASCI), we investigated the changes in expression levels of microRNA-9 (miR-9) and MCPIP1 in rat ASCI model.

METHOD

A total of 108 healthy rats were randomly divided into non-ASCI group (n=18) and five ASCI groups, 6h, 12h, 24h, 3 days and 7 days, representing the experimental time points following ASCI (n=18 per group). Hematoxylin and eosin (HE) staining was used to assess the ASCI damage, and quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH) were employed for the detection of miR-9 and MCPIP1 mRNA expression.

RESULTS

HE staining results showed normal neuronal morphology in the non-ASCI group, but spinal cord tissue at 6h after ASCI showed developing neuronal necrosis. Acute inflammatory response was evident at 12h and 24h, with immune cells infiltrating into the gray matter. Vascular permeability increased and the nerve cells in gray-white matter exhibited extensive damage and necrosis at 24h and 7 days after ASCI. MiR-9 expression in ASCI tissue was significantly lower than that in normal spinal cord tissue. Statistical analysis showed a significant decrease in miR-9 expression in all the ASCI groups, compared to the non-ASCI group. Results from real-time PCR analysis revealed that MCPIP1 expression in all the ASCI groups was significantly higher than the non-ASCI group, and MCPIP1 expressions gradually increased with times at 6h-24h after ASCI. ISH revealed the following results after ASCI (1) miR-9 and MCPIP1 mRNA expression mainly distributed in ventral horn motor neurons, (2) miR-9 expression was high at 7 day after ASCI and (3) in the non-ASCI group, MCPIP1 expression was high at 6h, 12h, 24h and 3 days.

CONCLUSION

MCPIP1 is significantly up-regulated after ASCI. The negative relationship between MCPIP1 and miR-9 suggest that MCPIP1 mRNA could be a target of miR-9 during ASCI. Thus, miR-9 is a marker for apoptosis in neurons, and an excellent therapeutic target for ASCI patients.

Methylprednisolone for the Treatment of Patients with Acute Spinal Cord Injuries: A Systematic Review and Meta-Analysis

Previous meta-analyses of methylprednisolone (MPS) for patients with acute traumatic spinal cord injuries (TSCIs) have not addressed confidence in the quality of evidence used for pooled effect estimates, and new primary studies have been recently published. We aimed to determine whether MPS improves motor recovery and is associated with increased risks for adverse events. We searched MEDLINE, EMBASE, and The Cochrane Library, and two reviewers independently screened articles, extracted data, and evaluated risk of bias. We pooled outcomes from randomized, controlled trials (RCTs) and controlled observational studies separately and used the Grades of Recommendation, Assessment, Development, and Evaluation approach to evaluate confidence. We included four RCTs and 17 observational studies. MPS was not associated with an increase in long-term motor score recovery (two RCTs: 335 participants; mean difference [MD], −1.11; 95% confidence interval [CI], −4.75 to 2.53; p = 0.55, low confidence; two observational studies: 528 participants; MD, 1.37; 95% CI, −3.08 to 5.83; p = 0.55, very low confidence) or improvement by at least one motor grade (three observational studies: 383 participants; risk ratio [RR], 0.84; 95% CI, 0.53–1.33; p = 0.46, very low confidence). Evidence from two RCTs demonstrated superior short-term motor score improvement if MPS was administered within 8 h of injury (two RCTs: 250 participants; MD, 4.46; 95% CI, 0.97–7.94; p = 0.01, low confidence), but risk of bias and imprecision limit confidence in these findings. Observational studies demonstrated a significantly increased risk for gastrointestinal bleeding (nine studies: 2857 participants; RR, 2.18; 95% CI, 1.13–4.19; p = 0.02, very low confidence), but RCTs did not. Pooled evidence does not demonstrate a significant long-term benefit for MPS in patients with acute TSCIs and suggests it may be associated with increased gastrointestinal bleeding. These findings support current guidelines against routine use, but strong recommendations are not warranted because confidence in the effect estimates is limited.

Antioxidant and anti-inflammatory effects of intravenously injected adipose derived mesenchymal stem cells in dogs with acute spinal cord injury

Introduction

Mesenchymal stem cells can potentially be used in therapy for spinal cord injury (SCI). Methylprednisolone sodium succinate (MPSS) has been used as a scavenging agent in acute SCI treatment, but its use no longer recommended. This study aimed to identify ways to reduce the usage and risk of high doses of glucocorticoid steroids, and determine whether AD-MSCs could be used as an early alternative treatment modality for acute SCI.

Methods

Sixteen adult beagle dogs with SCI were assigned to four treatment groups: control, MPSS, AD-MSCs, and AD-MSCs + MPSS. Additionally, one dog was used to evaluate the distribution of AD-MSCs in the body after injection. AD-MSCs (1 × 10⁷ cells) were injected intravenously once a day for 3 days beginning at 6 hours post-SCI. MPSS was also injected intravenously according to the standard protocol for acute SCI. A revised Tarlov scale was used to evaluate hindlimb functional recovery. The levels of markers for oxidative metabolism (3-nitrotyrosine, 4-hydroxynonenal, and protein carbonyl) and inflammation (cyclooxygenase-2, interleukin-6, and tumor necrosis factor-α) were also measured.

Results

At 7 days post-treatment, hindlimb movement had improved in the AD-MSCs and AD-MSCs + MPSS groups; however, subjects in the groups treated with MPSS exhibited gastrointestinal hemorrhages. Hematoxylin and eosin staining revealed fewer hemorrhages and lesser microglial infiltration in the AD-MSCs group. The green fluorescent protein-expressing AD-MSCs were clearly detected in the lung, spleen, and injured spinal cord; however, these cells were not detected in the liver and un-injured spinal cord. Levels of 3-nitrotyrosine were decreased in the MPSS and AD-MSCs + MPSS groups; 4-hydroxynenonal and cyclooxygenase-2 levels were decreased in all treatment groups; and interleukin-6, tumor necrosis factor-α, and phosphorylated-signal transducer and activator transcription 3 levels were decreased in the AD-MSCs and AD-MSCs + MPSS groups.

Conclusion

Our results suggest that early intravenous injection of AD-MSCs after acute SCI may prevent further damage through enhancement of antioxidative and anti-inflammatory mechanisms, without inducing adverse effects. Additionally, this treatment could also be used as an alternative intravenous treatment modality for acute SCI.

Methylprednisolone for the Treatment of Patients with Acute Spinal Cord Injuries: A Propensity Score-Matched Cohort Study from a Canadian Multi-Center Spinal Cord Injury Registry

In prior analyses of the effectiveness of methylprednisolone for the treatment of patients with acute traumatic spinal cord injuries (TSCIs), the prognostic importance of patients' neurological levels of injury and their baseline severity of impairment has not been considered. Our objective was to determine whether methylprednisolone improved motor recovery among participants in the Rick Hansen Spinal Cord Injury Registry (RHSCIR). We identified RHSCIR participants who received methylprednisolone according to the Second National Spinal Cord Injury Study (NASCIS-II) protocol and used propensity score matching to account for age, sex, time of neurological exam, varying neurological level of injury, and baseline severity of neurological impairment. We compared changes in total, upper extremity, and lower extremity motor scores using the Wilcoxon signed-rank test and performed sensitivity analyses using negative binomial regression. Forty-six patients received methylprednisolone and 1555 received no steroid treatment. There were no significant differences between matched participants for each of total (13.7 vs. 14.1, respectively; p=0.43), upper extremity (7.3 vs. 6.4; p=0.38), and lower extremity (6.5 vs. 7.7; p=0.40) motor recovery. This result was confirmed using a multivariate model and, as predicted, only cervical (C1-T1) rather than thoracolumbar (T2-L3) injury levels (p<0.01) and reduced baseline injury severity (American Spinal Injury Association [ASIA] Impairment Scale grades; p<0.01) were associated with greater motor score recovery. There was no in-hospital mortality in either group; however, the NASCIS-II methylprednisolone group had a significantly higher rate of total complications (61% vs. 36%; p=0.02) NASCIS-II methylprednisolone did not improve motor score recovery in RHSCIR patients with acute TSCIs in either the cervical or thoracic spine when the influence of anatomical level and severity of injury were included in the analysis. There was a significantly higher rate of total complications in the NASCIS-II methylprednisolone group. These findings support guideline recommendations against routine administration of methylprednisolone in acute TSCI.

Investigational drugs for the treatment of spinal cord injury: review of preclinical studies and evaluation of clinical trials from Phase I to II

INTRODUCTION

Efforts in basic research have clarified mechanisms involved in spinal cord injury (SCI), and resulted in positive findings using experimental treatments including cell transplantation and drug administration preclinically. Based on accumulated results, various clinical trials have begun for human SCI.

AREAS COVERED

In this review, the authors focus on five investigational drugs: riluzole, minocycline, Rho protein antagonist, magnesium chloride in polyethylene glycol formulation, and basic fibroblast growth factor. All drugs have established safety and tolerability from Phase I clinical trials, and are now in Phase II. They have been proven to have neuroprotective and/or neuroregenerative effects in animal models of SCI.

EXPERT OPINION

To date, diverse drugs have been translated into clinical trials, but none have reached clinical application. A key gap was the lack of reliable biomarkers for SCI to fast-track Phase I/II trials. Furthermore, problems were often due to lack of adequate outcome assessments for both animal models and SCI patients. In order to advance clinical trials more quickly and with greater success, more clinically relevant animal models should be used in basic research. Clinically, it is indispensable to use appropriate outcome measurements and to construct a wide network among clinical centers to validate the efficacy of drugs.