Tracking Spinal Cord Injury: Differences in Cytokine Expression of IGF-1, TGF- B1, and sCD95l Can Be Measured in Blood Samples and Correspond to Neurological Remission in a 12-Week Follow-Up

Identification of Anoikis-Related Genes in Spinal Cord Injury: Bioinformatics and Experimental Validation

Spinal cord injury (SCI) is a serious disease without effective therapeutic strategies. To identify the potential treatments for SCI, it is extremely important to explore the underlying mechanism. Current studies demonstrate that anoikis might play an important role in SCI. In this study, we aimed to identify the key anoikis-related genes (ARGs) providing therapeutic targets for SCI. The mRNA expression matrix of GSE45006 was downloaded from the Gene Expression Omnibus (GEO) database, and the ARGs were downloaded from the Molecular Signatures Database (MSigDB database). Then, the potential differentially expressed ARGs were identified. Next, correlation analysis, gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) analysis were employed for the differentially expressed ARGs. Moreover, miRNA-gene networks were constructed by the hub ARGs. Finally, RNA expression of the top ten hub ARGs was validated in the SCI cell model and rat SCI model. A total of 27 common differentially expressed ARGs were identified at different time points (1, 3, 7, and 14 days) following SCI. The GO and KEGG enrichment analysis of these ARGs indicated several enriched terms related to proliferation, cell cycle, and apoptotic process. The PPI results revealed that most of the ARGs interacted with each other. Ten hub ARGs were further screened, and all the 10 genes were validated in the SCI cell model. In the rat model, only seven genes were validated eventually. We identified 27 differentially expressed ARGs of the SCI through bioinformatic analysis. Seven real hub ARGs (CCND1, FN1, IGF1, MYC, STAT3, TGFB1, and TP53) were identified eventually. These results may expand our understanding of SCI and contribute to the exploration of potential SCI targets.

Research Progress on the Effects of Different Exercise Modes on the Secretion of Exerkines After Spinal Cord Injury

Exercise training is a conventional treatment strategy throughout the entire treatment process for patients with spinal cord injury (SCI). Currently, exercise modalities for SCI patients primarily include aerobic exercise, endurance training, strength training, high-intensity interval training, and mind-body exercises. These exercises play a positive role in enhancing skeletal muscle function, inducing neuroprotection and regeneration, thereby influencing neural plasticity, reducing limb spasticity, and improving motor function and daily living abilities in SCI patients. However, the mechanism by which exercise training promotes functional recovery after SCI is still unclear, and there is no consensus on a unified and standardized exercise treatment plan. Different exercise methods may bring different benefits. After SCI, patients' physical activity levels decrease significantly due to factors such as motor dysfunction, which may be a key factor affecting changes in exerkines. The changes in exerkines of SCI patients caused by exercise training are an important and highly relevant and visual evaluation index, which may provide a new research direction for revealing the intrinsic mechanism by which exercise promotes functional recovery after SCI. Therefore, this article summarizes the changes in the expression of common exerkines (neurotrophic factors, inflammatory factors, myokines, bioactive peptides) after SCI, and intends to analyze the impact and role of different exercise methods on functional recovery after SCI from the perspective of exerkines mechanism. We hope to provide theoretical basis and data support for scientific exercise treatment programs after SCI.

Acute spinal cord injury serum biomarkers in human and rat: a scoping systematic review

STUDY DESIGN

Scoping systematic review.

OBJECTIVES

To summarize the available experimental clinical and animal studies for the identification of all CSF and serum-derived biochemical markers in human and rat SCI models.

SETTING

Tehran, Iran.

METHODS

In this scoping article, we systematically reviewed the electronic databases of PubMed, Scopus, WOS, and CENTRAL to retrieve current literature assessing the levels of different biomarkers in human and rat SCI models.

RESULTS

A total of 19,589 articles were retrieved and 6897 duplicated titles were removed. The remaining 12,692 studies were screened by their title/abstract and 12,636 were removed. The remaining 56 were considered for full-text assessment, and 11 papers did not meet the criteria, and finally, 45 studies were included. 26 studies were human observational studies comprising 1630 patients, and 19 articles studied SCI models in rats, including 832 rats. Upon reviewing the literature, we encountered a remarkable heterogeneity in terms of selected biomarkers, timing, and method of measurement, studied models, extent, and mechanism of injury as well as outcome assessment measures.

CONCLUSIONS

The specific expression and distribution patterns of biomarkers in relation to spinal cord injury (SCI) phases, and their varied concentrations over time, suggest that cerebrospinal fluid (CSF) and blood biomarkers are effective measures for assessing the severity of SCI.

A future blood test for acute traumatic spinal cord injury

Acute spinal cord injury (SCI) requires prompt diagnosis and intervention to minimize the risk of permanent neurologic deficit. Presently, SCI diagnosis and interventional planning rely on magnetic resonance imaging (MRI), which is not always available or feasible for severely injured patients. Detection of disease-specific biomarkers in biofluids via liquid biopsy may provide a more accessible and objective means of evaluating patients with suspected SCI. Cell-free DNA, which has been used for diagnosing and monitoring oncologic disease, may detect damage to spinal cord neurons via tissue-specific methylation patterns. Other types of biomarkers, including proteins and RNA species, have also been found to reflect neuronal injury and may be included as part of a multi-analyte assay to improve liquid biopsy performance. The feasibility of implementing liquid biopsy into current practices of SCI management is supported by the relative ease of blood sample collection as well as recent advancements in droplet digital polymerase chain reaction technology. In this review, we detail the current landscape of biofluid biomarkers for acute SCI and propose a framework for the incorporation of a putative blood test into the clinical management of SCI.

Motor rehabilitation as a therapeutic tool for spinal cord injury: New perspectives in immunomodulation

Traumatic spinal cord injury (SCI) is a devastating condition that significantly impacts motor, sensory and autonomic function in patients. Despite advances in therapeutic approaches, there is still no curative therapy currently available. Neuroinflammation is a persisting event of the secondary injury phase of SCI that affects functional recovery, and modulation of the inflammatory response towards a beneficial anti-inflammatory state can improve recovery in preclinical SCI models. In human SCI patients, rehabilitative exercise, or motor rehabilitation as we will refer to it from here on out, remains the cornerstone of treatment to increase functional capacity and prevent secondary health implications. Motor rehabilitation is known to have anti-inflammatory effects; however, current literature is lacking in the description of the effect of motor rehabilitation on inflammation in the context of SCI. Understanding the effect on different inflammatory markers after SCI should enable the optimization of motor rehabilitation as a therapeutic regime. This review extensively describes the effect of motor rehabilitation on selected inflammatory mediators in both preclinical and human SCI studies. Additionally, we summarize how the type, duration, and intensity of motor rehabilitation can affect the inflammatory response after SCI. In doing so, we introduce a new perspective on how motor rehabilitation can be optimized as an immunomodulatory therapy to improve patient outcome after SCI.

Advances in monitoring for acute spinal cord injury: a narrative review of current literature

Spinal cord injury (SCI) is a devastating condition that affects about 17,000 individuals every year in the United States, with approximately 294,000 people living with the ramifications of the initial injury. After the initial primary injury, SCI has a secondary phase during which the spinal cord sustains further injury due to ischemia, excitotoxicity, immune-mediated damage, mitochondrial dysfunction, apoptosis, and oxidative stress. The multifaceted injury progression process requires a sophisticated injury-monitoring technique for an accurate assessment of SCI patients. In this narrative review, we discuss SCI monitoring modalities, including pressure probes and catheters, micro dialysis, electrophysiologic measures, biomarkers, and imaging studies. The optimal next-generation injury monitoring setup should include multiple modalities and should integrate the data to produce a final simplified assessment of the injury and determine markers of intervention to improve patient outcomes.

Dynamics of biomarkers across the stages of traumatic spinal cord injury - implications for neural plasticity and repair

BACKGROUND

Traumatic spinal cord injury (SCI) is a complex medical condition causing significant physical disability and psychological distress. While the adult spinal cord is characterized by poor regenerative potential, some recovery of neurological function is still possible through activation of neural plasticity mechanisms. We still have limited knowledge about the activation of these mechanisms in the different stages after human SCI.

OBJECTIVE

In this review, we discuss the potential role of biomarkers of SCI as indicators of the plasticity mechanisms at work during the different phases of SCI.

METHODS

An extensive review of literature related to SCI pathophysiology, neural plasticity and humoral biomarkers was conducted by consulting the PubMed database. Research and review articles from SCI animal models and SCI clinical trials published in English until January 2021 were reviewed. The selection of candidates for humoral biomarkers of plasticity after SCI was based on the following criteria: 1) strong evidence supporting involvement in neural plasticity (mandatory); 2) evidence supporting altered expression after SCI (optional).

RESULTS

Based on selected findings, we identified two main groups of potential humoral biomarkers of neural plasticity after SCI: 1) neurotrophic factors including: Brain derived neurotrophic factor (BDNF), Nerve growth factor (NGF), Neurotrofin-3 (NT-3), and Insulin-like growth factor 1 (IGF-1); 2) other factors including: Tumor necrosis factor-alpha (TNF-α), Matrix Metalloproteinases (MMPs), and MicroRNAs (miRNAs). Plasticity changes associated with these biomarkers often can be both adaptive (promoting functional improvement) and maladaptive. This dual role seems to be influenced by their concentrations and time-window during SCI.

CONCLUSIONS

Further studies of dynamics of biomarkers across the stages of SCI are necessary to elucidate the way in which they reflect the remodeling of neural pathways. A better knowledge about the mechanisms underlying plasticity could guide the selection of more appropriate therapeutic strategies to enhance positive spinal network reorganization.

Insulin-like growth factor 1 promotes neurological functional recovery after spinal cord injury through inhibition of autophagy via the PI3K/Akt/mTOR signaling pathway

Spinal cord injury (SCI) is a serious trauma; however, the mechanisms underlying the role of insulin-like growth factor 1 (IGF-1) in autophagy following SCI remain to be elucidated. The present study aimed to investigate the therapeutic effect of IGF-1 on SCI and to determine whether IGF-1 regulates autophagy via the PI3K/Akt/mTOR signaling pathway. SH-SY5Y neuroblastoma cells were assigned to the H₂O₂, IGF-1 and control groups to investigate subsequent neuron injury in vitro. An MTT assay was performed to evaluate cell survival. In addition, Sprague-Dawley rats were randomly assigned to SCI, SCI + IGF-1 and sham groups, and Basso-Beatlie-Bresnahan scores were assessed to determine rat neurological function. Western blotting was used to analyze the autophagy level and the activation of the PI3K/Akt/mTOR signaling pathway. Cell survival was increased significantly in the IGF-1 group compared with the control group in vitro (P<0.05). Furthermore, neurological function was improved in the SCI + IGF-1 group compared with the control group in vivo (P<0.05). The western blotting results further demonstrated that LC3II/LC3I expression was increased in the IGF-1 group compared with the sham group in vivo and compared with the control group in vitro (both P<0.05). In the SCI + IGF-1 group, the expression levels of PI3K, phosphorylated (p)-Akt and p-mTOR were higher compared with those in the sham and SCI groups in vivo (P<0.05). Moreover, in the IGF-1 group, the expression levels of p-Akt and p-mTOR were higher compared with the control and the H₂O₂ groups in vitro (P<0.05). Collectively, the results of the present study suggested that IGF-1 promoted functional recovery in rats following SCI through neuroprotective effects. Furthermore, the underlying mechanism may involve activation of the PI3K/Akt/mTOR signaling pathway, followed by inhibition of autophagy. However, further investigation into the association between IGF-1-regulated autophagy and the activation of different subtypes of PI3K is required.

Application value of biofluid-based biomarkers for the diagnosis and treatment of spinal cord injury

Recent studies in patients with spinal cord injuries (SCIs) have confirmed the diagnostic potential of biofluid-based biomarkers, as a topic of increasing interest in relation to SCI diagnosis and treatment. This paper reviews the research progress and application prospects of recently identified SCI-related biomarkers. Many structural proteins, such as glial fibrillary acidic protein, S100-β, ubiquitin carboxy-terminal hydrolase-L1, neurofilament light, and tau protein were correlated with the diagnosis, American Spinal Injury Association Impairment Scale, and prognosis of SCI to different degrees. Inflammatory factors, including interleukin-6, interleukin-8, and tumor necrosis factor α, are also good biomarkers for the diagnosis of acute and chronic SCI, while non-coding RNAs (microRNAs and long non-coding RNAs) also show diagnostic potential for SCI. Trace elements (Mg, Se, Cu, Zn) have been shown to be related to motor recovery and can predict motor function after SCI, while humoral markers can reflect the pathophysiological changes after SCI. These factors have the advantages of low cost, convenient sampling, and ease of dynamic tracking, but are also associated with disadvantages, including diverse influencing factors and complex level changes. Although various proteins have been verified as potential biomarkers for SCI, more convincing evidence from large clinical and prospective studies is thus required to identify the most valuable diagnostic and prognostic biomarkers for SCI.

Predicting neurological recovery after traumatic spinal cord injury by time-resolved analysis of monocyte subsets

Monocytes and lymphocytes elicit crucial activities for the regenerative processes after various types of injury. The survival of neurons exposed to mechanical and oxidative stress after traumatic spinal cord injury (TSCI) depends on a multitude of factors. The current study sought to evaluate a correlation between remission after TSCI and dynamics of monocyte subsets in respect to the lymphocytes' responsive potential, cytokine expression, patterns of trace element concentration and clinical covariates. We examined prospectively 18 (3 female, 15 male) patients after TSCI. Blood samples were drawn at admission and 4 h, 9 h, 12 h, 1 and 3 days as well as 1 and 2 weeks and 1, 2 and 3 months after the trauma. Analysis of cytokines (CCL-2, IL-10, Enolase 2, CXCL-12, TGF- β1, TGF- β2) was performed using a multiplex cytokine panel. Plasma trace element concentrations of selenium, copper and zinc were determined by total reflection X-ray fluorescence analysis, Neopterin, selenoprotein P (SELENOP) and ceruloplasmin (CP) by enzyme-linked immunosorbent assay (ELISA) and selenium binding protein 1 (SELENBP1) by luminometric immunoassay (LIA). The responsive potential of lymphocytes was assessed via transformation tests. The monocyte subsets (classical, intermediate, and non-classical) and expression of CD14, CD16, CXCR4 and intracellular IL-10 were identified using a multi-colour flow cytometry analysis. The dynamics of the cluster of intermediate CD14-/CD16+/IL10+/CXCR4int monocytes differed significantly between patients with an absence of neurological remission (G0) from those with an improvement (G1) by 1 or 2 AIS steps (Kruskal-Wallis Test, p = 0.010, G0 < G1, AIS+: 1 < G1, AIS+: 2) in the first 24 h. These dynamics were associated inversely with an increase in Enolase and SELENBP1 14 d after the injury. In the elastic net regularised model, we identified an association between the increase of a subpopulation of intermediate CD14-/CD16+/IL10+/CXCR4int monocytes and exacerbated immune response within 24 h after the injury. These findings are reflected in the consistently elevated response to mitogen stimulation of the lymphocytes of patients with significant neurological remission. Early elevated concentrations of CD14-/CD16+/IL10+/CXCR4int monocytes were related to higher odds of CNS regeneration and enhanced neurological remission. The cluster-dynamics of CD14-/CD16+/IL10+/CXCR4int monocytes in the early-acute phase after the injury revealed a maximum of prognostic information regarding neurological remission (mean parameter estimate: 0.207; selection count: 818/1000 repetitions). We conclude that early dynamics in monocyte subsets allow a good prediction of recovery from TSCI.

Early Management of Spinal Cord Injury: WFNS Spine Committee Recommendations

Scientific knowledge today is being generated more rapidly than we can assimilate thus requiring continuous review of gold-standards for diagnosis and treatment of specific pathologies. The aim of this paper is to provide an update on the best early management of spinal cord injury (SCI), in order to produce acceptable worldwide recommendations to standardize clinical practice as much as possible.The WFNS Spine Committee voted recommendations regarding management of SCI based on literature review of the last 10 years. The committee stated 9 recommendations on 3 main topics: (1) clinical assessment and classification of SCI; (2) emergency care and early management; (3) cardiopulmonary management. American Spinal Injury Association impairment scale, Spinal Cord Independence Measure, and International Spinal Cord Injury Basic Pain Data Set are considered the most useful and feasible in emergency evaluation and follow-up in case of SCI. Magnetic resonance imaging is the most indicated examination to evaluate patients with symptomatic SCI. In early phase, correction of hypotension (systolic blood pressure < 90 mmHg), and bradycardia are strongly recommended. Surgical decompression should be performed as soon as possible with the ideal surgical time being within 8 hours for both complete and incomplete lesions.

Thermosensitive heparin-poloxamer hydrogel encapsulated bFGF and NGF to treat spinal cord injury

The application of growth factors (GFs) for treating chronic spinal cord injury (SCI) has been shown to promote axonal regeneration and functional recovery. However, direct administration of GFs is limited by their rapid degradation and dilution at the injured sites. Moreover, SCI recovery is a multifactorial process that requires multiple GFs to participate in tissue regeneration. Based on these facts, controlled delivery of multiple growth factors (GFs) to lesion areas is becoming an attractive strategy for repairing SCI. Presently, we developed a GFs‐based delivery system (called GFs‐HP) that consisted of basic fibroblast growth factor (bFGF), nerve growth factor (NGF) and heparin‐poloxamer (HP) hydrogel through self‐assembly mode. This GFs‐HP was a kind of thermosensitive hydrogel that was suitable for orthotopic administration in vivo. Meanwhile, a 3D porous structure of this hydrogel is commonly used to load large amounts of GFs. After single injection of GFs‐HP into the lesioned spinal cord, the sustained release of NGF and bFGF from HP could significantly improve neuronal survival, axon regeneration, reactive astrogliosis suppression and locomotor recovery, when compared with the treatment of free GFs or HP. Moreover, we also revealed that these neuroprotective and neuroregenerative effects of GFs‐HP were likely through activating the phosphatidylinositol 3 kinase and protein kinase B (PI3K/Akt) and mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK) signalling pathways. Overall, our work will provide an effective therapeutic strategy for SCI repair.

Zinc Concentration Dynamics Indicate Neurological Impairment Odds after Traumatic Spinal Cord Injury

Traumatic Spinal Cord Injury (TSCI) is debilitating and often results in a loss of motor and sensory function caused by an interwoven set of pathological processes. Oxidative stress and inflammatory processes are amongst the critical factors in the secondary injury phase after TSCI. The essential trace element Zinc (Zn) plays a crucial role during this phase as part of the antioxidant defense system. The study aims to determine dynamic patterns in serum Zn concentration in patients with TSCI and test for a correlation with neurological impairment. A total of 42 patients with TSCI were enrolled in this clinical observational study. Serum samples were collected at five different points in time after injury (at admission, and after 4 h, 9 h, 12 h, 24 h, and 3 days). The analysis of the serum Zn concentrations was conducted by total reflection X-ray fluorescence (TXRF). The patients were divided into two groups—a study group S (n = 33) with neurological impairment, including patients with remission (G1, n = 18) and no remission (G0, n = 15) according to a positive AIS (American Spinal Injury Association (ASIA) Impairment Scale) conversion within 3 months after the trauma; and a control group C (n = 9), consisting of subjects with vertebral fractures without neurological impairment. The patient data and serum concentrations were examined and compared by non-parametric test methods to the neurological outcome. The median Zn concentrations in group S dropped within the first 9 h after injury (964 µg/L at admission versus 570 µg/L at 9 h, p < 0.001). This decline was stronger than in control subjects (median of 751 µg/L versus 729 µg/L, p = 0.023). A binary logistic regression analysis including the difference in serum Zn concentration from admission to 9 h after injury yielded an area under the curve (AUC) of 82.2% (CI: 64.0–100.0%) with respect to persistent neurological impairment. Early Zn concentration dynamics differed in relation to the outcome and may constitute a helpful diagnostic indicator for patients with spinal cord trauma. The fast changes in serum Zn concentrations allow an assessment of neurological impairment risk on the first day after trauma. This finding supports strategies for improving patient care by avoiding strong deficits via adjuvant nutritive measures, e.g., in unresponsive patients after trauma.

Selenium and copper status - potential signposts for neurological remission after traumatic spinal cord injury

INTRODUCTION

Traumatic Spinal Cord Injury (TSCI) is a severe incident resulting in loss of motor and sensory function caused by complex pathological mechanisms including massive oxidative stress and extensive inflammatory processes. The essential trace elements selenium (Se) and copper (Cu) play crucial roles as part of the antioxidant defense.

HYPOTHESIS

Remission after TSCI is associated with characteristic dynamics of early changes in serum Cu and Se status.

STUDY DESIGN

Single-center prospective observational study.

PATIENTS AND METHODS

Serum samples from TSCI patients were analyzed (n = 52); 21 recovered and showed a positive abbreviated injury score (AIS) conversion within 3 months (G1), whereas 21 had no remission (G0). Ten subjects with vertebral fractures without neurological impairment served as control (C). Different time points (at admission, and after 4, 9, 12, and 24 h) were analyzed for total serum Se and Cu concentrations by total reflection X-ray fluorescence, and for Selenoprotein P (SELENOP) and Ceruloplasmin (CP) by sandwich ELISA.

RESULTS

At admission, CP and SELENOP concentrations were higher in the remission group (G1) than in the non-remission group (G0). Within 24 h, there were marginal changes in Se, SELENOP, Cu and CP concentrations in the groups of controls (C) and G0. In contrast, these parameters decreased significantly in G1. Binary logistic regression analysis including Cu and Se levels at admission in combination with Se and CP levels after 24 h allowed a prediction for potential remission, with an area under the curve (AUC) of 87.7% (CI: 75.1%-100.0%).

CONCLUSION

These data indicate a strong association between temporal changes of the Se and Cu status and the clinical outcome after TSCI. The dynamics observed may reflect an ongoing redistribution of the trace elements in favor of a better anti-inflammatory response and a more successful neurological regeneration.

The Role of Magnesium in the Secondary Phase After Traumatic Spinal Cord Injury. A Prospective Clinical Observer Study

In the secondary injury phase after traumatic spinal cord injury (TSCI), oxidative stress and neuroinflammatory responses at the site of injury constitute crucial factors controlling damage extent and may serve as potential therapeutic targets. We determined Magnesium (Mg) serum concentration dynamics in context with the potential of neurological remission in patients with TSCI as Mg is suspected to limit the production of reactive oxygen species and reduce lipid peroxidation. A total of 29 patients with acute TSCI were enrolled, and blood samples were drawn over 3 months at 11 time-points and Mg quantification was performed. Patients were divided into those with (G1, n = 18) or without neurological remission (G0, n = 11). Results show a slight drop in Mg level during the first 4 h after injury, then remained almost unchanged in G1, but increased continuously during the first 7 days after injury in G0. At day 7 Mg concentrations in G1 and G0 were significantly different (p = 0.039, G0 > G1). Significant differences were detected between patients in G1 that presented an AIS (ASIA Impairment Scale) conversion of 1 level versus those with more than 1 level (p = 0.014, G1 AIS imp. = +1 > G1 AI imp. > +1). Low and decreasing levels of Mg within the first 7 days are indicative of a high probability of neurological remission, whereas increasing levels are associated with poor neurological outcome.

Myelin status and oligodendrocyte lineage cells over time after spinal cord injury: What do we know and what still needs to be unwrapped?

Spinal cord injury (SCI) affects over 17,000 individuals in the United States per year, resulting in sudden motor, sensory and autonomic impairments below the level of injury. These deficits may be due at least in part to the loss of oligodendrocytes and demyelination of spared axons as it leads to slowed or blocked conduction through the lesion site. It has long been accepted that progenitor cells form new oligodendrocytes after SCI, resulting in the acute formation of new myelin on demyelinated axons. However, the chronicity of demyelination and the functional significance of remyelination remain contentious. Here we review work examining demyelination and remyelination after SCI as well as the current understanding of oligodendrocyte lineage cell responses to spinal trauma, including the surprisingly long-lasting response of NG2+ oligodendrocyte progenitor cells (OPCs) to proliferate and differentiate into new myelinating oligodendrocytes for months after SCI. OPCs are highly sensitive to microenvironmental changes, and therefore respond to the ever-changing post-SCI milieu, including influx of blood, monocytes and neutrophils; activation of microglia and macrophages; changes in cytokines, chemokines and growth factors such as ciliary neurotrophic factor and fibroblast growth factor-2; glutamate excitotoxicity; and axon degeneration and sprouting. We discuss how these changes relate to spontaneous oligodendrogenesis and remyelination, the evidence for and against demyelination being an important clinical problem and if remyelination contributes to motor recovery.

Neurological recovery following traumatic spinal cord injury: a systematic review and meta-analysis

OBJECTIVE

Predicting neurological recovery following traumatic spinal cord injury (TSCI) is a complex task considering the heterogeneous nature of injury and the inconsistency of individual studies. This study aims to summarize the current evidence on neurological recovery following TSCI by use of a meta-analytical approach, and to identify injury, treatment, and study variables with prognostic significance.

METHODS

A literature search in MEDLINE and EMBASE was performed, and studies reporting follow-up changes in American Spinal Injury Association (ASIA) Impairment Scale (AIS) or Frankel or ASIA motor score (AMS) scales were included in the meta-analysis. The proportion of patients with at least 1 grade of AIS/Frankel improvement, and point changes in AMS were calculated using random pooled effect analysis. The potential effect of severity, level and mechanism of injury, type of treatment, time and country of study, and follow-up duration were evaluated using meta-regression analysis.

RESULTS

A total of 114 studies were included, reporting AIS/Frankel changes in 19,913 patients and AMS changes in 6920 patients. Overall, the quality of evidence was poor. The AIS/Frankel conversion rate was 19.3% (95% CI 16.2-22.6) for patients with grade A, 73.8% (95% CI 69.0-78.4) for those with grade B, 87.3% (95% CI 77.9-94.8) for those with grade C, and 46.5% (95% CI 38.2-54.9) for those with grade D. Neurological recovery was significantly different between all grades of SCI severity in the following order: C > B > D > A. Level of injury was a significant predictor of recovery; recovery rates followed this pattern: lumbar > cervical and thoracolumbar > thoracic. Thoracic SCI and penetrating SCI were significantly more likely to result in complete injury. Penetrating TSCI had a significantly lower recovery rate compared to blunt injury (OR 0.76, 95% CI 0.62-0.92; p = 0.006). Recovery rate was positively correlated with longer follow-up duration (p = 0.001). Studies with follow-up durations of approximately 6 months or less reported significantly lower recovery rates for incomplete SCI compared to studies with long-term (3-5 years) follow-ups.

CONCLUSIONS

The authors' meta-analysis provides an overall quantitative description of neurological outcomes associated with TSCI. Moreover, they demonstrated how neurological recovery after TSCI is significantly dependent on injury factors (i.e., severity, level, and mechanism of injury), but is not associated with type of treatment or country of origin. Based on these results, a minimum follow-up of 12 months is recommended for TSCI studies that include patients with neurologically incomplete injury.

Biomarkers in Spinal Cord Injury: Prognostic Insights and Future Potentials

Spinal Cord Injury (SCI) is a major challenge in Neurotrauma research. Complex pathophysiological processes take place immediately after the injury and later on as the chronic injury develops. Moreover, SCI is usually accompanied by traumatic injuries because the most common modality of injury is road traffic accidents and falls. Patients develop significant permanent neurological deficits that depend on the extent and the location of the injury itself and in time they develop further neurological and body changes that may risk their mere survival. In our review, we explored the recent updates with regards to SCI biomarkers. We observed two methods that may lead to the appearance of biomarkers for SCI. First, during the first few weeks following the injury the Blood Spinal Cord Barrier (BSCB) disruption that releases several neurologic structure components from the injured tissue. These components find their way to Cerebrospinal Fluid (CSF) and the systemic circulation. Also, as the injury develops several components of the pathological process are expressed or released such as in neuroinflammation, apoptosis, reactive oxygen species, and excitotoxicity sequences. Therefore, there is a growing interest in examining any correlations between these components and the degrees or the outcomes of the injury. Additionally, some of the candidate biomarkers are theorized to track the progressive changes of SCI which offers an insight on the patients' prognoses, potential-treatments-outcomes assessment, and monitoring the progression of the complications of chronic SCI such as Pressure Ulcers and urinary dysfunction. An extensive literature review was performed covering literature, published in English, until February 2018 using the Medline/PubMed database. Experimental and human studies were included and titles, PMID, publication year, authors, biomarkers studies, the method of validation, relationship to SCI pathophysiology, and concluded correlation were reported. Potential SCI biomarkers need further validation using clinical studies. The selection of the appropriate biomarker group should be made based on the stage of the injuries, the accompanying trauma and with regards to any surgical, or medical interference that might have been done. Additionally, we suggest testing multiple biomarkers related to the several pathological changes coinciding to offer a more precise prediction of the outcome.

Relation of selenium status to neuro-regeneration after traumatic spinal cord injury

INTRODUCTION

The trace element selenium (Se) is crucial for the biosynthesis of selenoproteins. Both neurodevelopment and the survival of neurons that are subject to stress depend on a regular selenoprotein biosynthesis and sufficient Se supply by selenoprotein P (SELENOP).

HYPOTHESIS

Neuro-regeneration after traumatic spinal cord injury (TSCI) is related to the Se status.

STUDY DESIGN

Single-centre prospective observational study.

PATIENTS AND METHODS

Three groups of patients with comparable injuries were studied; vertebral fractures without neurological impairment (n = 10, group C), patients with TSCI showing no remission (n = 9, group G0), and patients with remission developing positive abbreviated injury score (AIS) conversion within 3 months (n = 10, group G1). Serum samples were available from different time points (upon admission, and after 4, 9 and 12 h, 1 and 3 days, 1 and 2 weeks, and 1, 2 and 3 months). Serum trace element concentrations were determined by total reflection X-ray fluorescence, SELENOP by ELISA, and further parameters by laboratory routine.

RESULTS

Serum Se and SELENOP concentrations were higher on admission in the remission group (G1) as compared to G0. During the first week, both parameters remained constant in C and G0, whereas they declined significantly in the remission group. Similarly, the concentration changes between admission and 24 h were most pronounced in this group of recovering patients (G1). Binary logistic regression analysis including the delta of Se and SELENOP within the first 24 h indicated an AUC of 90.0% (CI: 67.4%-100.0%) with regards to predicting the outcome after TSCI.

CONCLUSION

A Se deficit might constitute a risk factor for poor outcome after TSCI. A dynamic decline of serum Se and SELENOP concentrations after admission may reflect ongoing repair processes that are associated with higher odds for a positive clinical outcome.

CCL-2 as a possible early marker for remission after traumatic spinal cord injury

STUDY DESIGN

Prospective observational study.

OBJECTIVES

To describe the correlation between CCL-2, CCL-3, CCL-4 and CXCL-5 serum levels and remission after traumatic spinal cord injury (SCI) in a human protocol compared with animal studies.

SETTING

Germany, Rhineland-Palatinate (Rheinland-Pfalz).

METHODS

We examined the serum levels of CCL-2, CCL-3, CCL-4 and CXCL-5 over a 12-week period; in particular, at admission and 4, 9 and 12 h, 1 and 3 days and 1, 2, 4, 8 and 12 weeks after trauma. According to our study design, we matched 10 patients with TSCI and neurological remission with 10 patients with an initial ASIA A grade and no neurological remission. In all, 10 patients with vertebral fracture without neurological deficits served as control. Our analysis was performed using a Luminex Cytokine Panel. Multivariate logistic regression models were used to examine the predictive value with respect to neurological remission vs no neurological remission.

RESULTS

The results of our study showed differences in the serum expression patterns of CCL-2 in association with the neurological remission (CCL-2 at admission P=0.013). Serum levels of CCL-2 and CCL-4 were significantly different in patients with and without neurological remission. The favored predictive model resulted in an area under the curve (AUC) of 93.1% in the receiver operating characteristic (ROC) analysis.

CONCLUSIONS

Our results indicate that peripheral serum analysis is a suitable concept for predicting the patient's potential for neurological remission after TSCI. Furthermore, the initial CCL-2 concentration provides an additional predictive value compared with the NLI (neurological level of injury). Therefore, the present study introduces a promising approach for future monitoring concepts and tracking techniques for current therapies. The results indicate that future investigations with an enlarged sample size are needed in order to develop monitoring, prognostic and scoring systems.