Serum Biomarkers and Clinical Outcomes in Traumatic Spinal Cord Injury: Prospective Cohort Study

Interleukin-6 in Spinal Cord Injury: Could Immunomodulation Replace Immunosuppression in the Management of Acute Traumatic Spinal Cord Injuries?

Traumatic spinal cord injuries (SCI) result in devastating impairment to an individual's functional ability. The pathophysiology of SCI is related to primary injury but further propagated by secondary reactions to injury, such as inflammation and oxidation. The inflammatory and oxidative cascades ultimately cause demyelination and Wallerian degeneration. Currently, no treatments are available to treat primary or secondary injury in SCI, but some studies have shown promising results by lessening secondary mechanisms of injury. Interleukins (ILs) have been described as key players in the inflammation cascade after neuronal injury; however, their role and possible inhibition in the context of acute traumatic SCIs have not been widely studied. Here, we review the relationship between SCI and IL-6 concentrations in the CSF and serum of individuals after traumatic SCIs. Furthermore, we explore the dual IL-6 signaling pathways and their relevance for future IL-6 targeted therapies in SCI.

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.

Plasma GDNF levels in spinal dysraphism and its relation with neurological impairment in children: A point of care study

AIMS

GDNF plays a crucial role in the stimulation of recovery, neuroplasticity and synaptic reorganization after spinal cord injury providing neuroprotection and neuroregeneration. Plasma GDNF levels are upregulated in cases of spina bifida owing to the intrauterine damage of the exposed spinal cord. Our aim was to compare the plasma GDNF levels in patients of spina bifida with non-spina bifida cases and assess the correlation with neurological impairment at one year of follow up.

METHODS

Single centre prospective analysis of cases of spina bifida from 2020 to 2022 at presentation and after one year of follow up post-surgery. Cases with hernia and hydrocele without any other disorders were recruited into the control group. Plasma GDNF levels were assessed with immunoassay kits and compared with neurological involvement.

RESULTS

85 cases were included in the study. GDNF levels were elevated in cases compared to controls (mean 6.62 vs 1.76) with significant p value (<0.01). Same was observed for open and closed defects (mean 7.63 vs 4.86: p < 0.01). At follow up of 52 cases post-surgery cases with neurogenic bladder with abnormal urodynamic studies, sphincter involvement and motor impairment had significantly elevated baseline levels of GDNF compared with those who did not have this neurological impairment (p < 0.01).

DISCUSSION

The neurotrophic factor up-regulation can reflect an endogenous attempt at neuroprotection against the biochemical and molecular cascades triggered by the spinal cord damage. This upregulation can be represented as important biochemical markers of severe spinal cord damage and can be associated with severity of spine injury in MMC patients. Our results are in keeping with these findings, that, there were increased levels of plasma GDNF levels in cases of spinal dysraphism compared to control population. Also, the type of lesion reflecting the severity whether a closed or an open dysraphism, showed significant difference in levels between them suggesting, yet again, more damage in open defect as expected. The levels were higher with involvement of bladder, sphincter and lower limb power.

CONCLUSION

There is significant elevation of plasma GDNF levels in cases of spina bifida and this elevation is proportional to the degree of spinal damage and hence the neurological impairment. GDNF levels are a good predictor for assessing the severity of the lesion and thus the outcome in these cases. Additional prospective and long-term studies with a larger cohort are needed for a better understanding of neurotrophin pattern modulation in MMC.

Targeting the Microbiome to Improve Gut Health and Breathing Function After Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition characterized by impaired motor and sensory function, as well as internal organ pathology and dysfunction. This internal organ dysfunction, particularly gastrointestinal (GI) complications, and neurogenic bowel, can reduce the quality of life of individuals with an SCI and potentially hinder their recovery. The gut microbiome impacts various central nervous system functions and has been linked to a number of health and disease states. An imbalance of the gut microbiome, i.e., gut dysbiosis, contributes to neurological disease and may influence recovery and repair processes after SCI. Here we examine the impact of high cervical SCI on the gut microbiome and find that transient gut dysbiosis with persistent gut pathology develops after SCI. Importantly, probiotic treatment improves gut health and respiratory motor function measured through whole-body plethysmography. Concurrent with these improvements was a systemic decrease in the cytokine tumor necrosis factor-alpha and an increase in neurite sprouting and regenerative potential of neurons. Collectively, these data reveal the gut microbiome as an important therapeutic target to improve visceral organ health and respiratory motor recovery after SCI.

Research Highlights

Cervical spinal cord injury (SCI) causes transient gut dysbiosis and persistent gastrointestinal (GI) pathology.Treatment with probiotics after SCI leads to a healthier GI tract and improved respiratory motor recovery.Probiotic treatment decreases systemic tumor necrosis factor-alpha and increases the potential for sprouting and regeneration of neurons after SCI.The gut microbiome is a valid target to improve motor function and secondary visceral health after SCI.

Serum glucose/potassium ratio as a clinical risk factor for predicting the severity and prognosis of acute traumatic spinal cord injury

OBJECTIVE

Acute traumatic Spinal cord injury (TSCI) is a devastating event that causes severe sensory and motor impairments as well as autonomic dysfunction in patients, yet relevant clinical biomarkers have not been established. This study aimed to determine the significance of the serum glucose/potassium ratio (GPR) in evaluating TSCI severity and predicting prognosis.

METHODS

An analysis of 520 clinical records of acute TSCI patients from January 2012 to June 2022 was conducted. The relationships between serum GPR and The American Spinal Injury Association Impairment Scale (AIS) grade 6-month post-trauma prognosis and the admission AIS grade were analyzed. To evaluate the discriminatory ability, a receiver operating characteristic curve (ROC) analysis was used. All methods were performed in accordance with the relevant guidelines and regulations.

RESULTS

Based on the initial assessment of AIS grade, 256 (49.2%) patients were categorized into the severe TSCI group (AIS A-B), and there was a significant correlation between the severe TSCI group and serum GPR (p < 0.001). Serum GPR was reduced in an AIS grade-dependent manner (R = - 0.540, p < 0.001). Of the 520 patients, 262 (50.4%) patients were classified as having a poor prognosis according to the AIS grade at discharge. Serum GPR was also reduced in an AIS grade at discharge-dependent manner (R = - 0.599, p < 0.001), and was significantly higher in the poor prognosis group compared to the good prognosis group (p < 0.001). Poor prognosis was significantly associated with sex (p = 0.009), severity of TSCI (p < 0.001), location of TSCI (p < 0.001), surgical decompression (p < 0.018), body temperature (p < 0.001), heart rate (p < 0.001), systolic arterial pressure (SAP) (p < 0.001), diastolic arterial pressure (DAP) (p < 0.001), serum GPR (p < 0.001), serum glucose (p < 0.001), serum potassium (p < 0.001), and white blood cell count (p = 0.003). Multivariate logistic regression analysis showed a significant correlation between poor prognosis and serum GPR (p = 0.023). The ROC analysis showed the area under the curve of serum GPR to be a poor predictor of prognosis in TSCI patients at 0.842 (95% confidence interval, 0.808-0.875).

CONCLUSION

There was a significant relationship between serum GPR and admission injury severity and the 6-month prognosis of acute TSCI patients. Serum GPR serves as a readily available clinical risk factor for predicting the severity and 6-month prognosis of acute traumatic spinal cord injury, which holds potential clinical significance for patients with TSCI.

Glial fibrillary acidic protein is a robust biomarker in cerebrospinal fluid and peripheral blood after traumatic spinal cord injury: a prospective pilot study

PURPOSE

Biochemical biomarkers to determine the injury severity and the potential for functional recovery of traumatic spinal cord injury (TSCI) are highly warranted; however, it remains to be clarified whether cerebrospinal fluid (CSF) or peripheral blood (PB) is the ideal sample media. This study aims to measure and compare biomarker concentrations in CSF and PB and to explore associations between biomarker concentrations and injury severity, i.e., American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade, and biomarker concentrations and clinical outcome, i.e., AIS grade improvement and Spinal Cord Independent Measure version III (SCIM-III) score.

METHODS

From 2018 to 2020, we conducted a single-center prospective pilot study of TSCI patients (n=15) and healthy controls (n=15). Sample collection and clinical outcome assessment were performed at median 13 h [IQR: 19], 9 days [IQR: 2], and 148 days [IQR: 49] after TSCI. Concentrations of neuron-specific enolase (NSE); glial fibrillary acid protein (GFAP); neurofilament light chain (NfL); interferon-γ (IFN-γ); interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, and IL-13; and tumor necrosis factor α (TNF-α) were measured and associated to clinical outcomes.

RESULTS

The biomarker concentrations were higher in CSF than PB. CSF concentrations of GFAP, NSE, IFN-y, TNF-a, IL-2, IL-12p70, IL-4, IL-10, and IL-13 and PB concentrations of GFAP and IFN-y were significantly associated with AIS grade, but not with AIS grade improvement or SCIM-III score.

CONCLUSIONS

Our results support GFAP as a potential diagnostic biomarker that may be measured in CSF as well as PB.

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.

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.

Early Predictors of Neurological Outcomes After Traumatic Spinal Cord Injury: A Systematic Review and Proposal of a Conceptual Framework

BACKGROUND

Neurological outcomes after traumatic spinal cord injury are variable and depend on patient-, trauma-, and treatment-related factors as well as on spinal cord injury characteristics, imaging, and biomarkers.

OBJECTIVE

The aims of the study were to identify and classify the early predictors of neurological outcomes after traumatic spinal cord injury.

DATA SOURCES

The Medline, PubMed, Embase, and the Cochrane Central Database were searched using medical subject headings. The search was extended to the reference lists of identified studies.

STUDY ELIGIBILITY CRITERIA

The study eligibility criteria were assessment of neurological outcomes as primary or secondary outcome, predictors collected during the acute phase after traumatic spinal cord injury, and multivariate design.

PARTICIPANTS

The participants were adult patients with traumatic spinal cord injury followed at least 3 mos after injury.

STUDY APPRAISAL AND SYNTHESIS METHODS

The quality of studies was assessed by two independent reviewers using the Study Quality Assessment Tools for Observational Cohort and Cross-sectional Studies. The studies' narrative synthesis relied on a classification of the predictors according to quantity, quality, and consistency of the evidence. Results were summarized in a conceptual framework.

RESULTS

Forty-nine articles were included. The initial severity of traumatic spinal cord injury (American Spinal Injury Association Impairment Scale, motor score, and neurological level of injury) was the strongest predictor of neurological outcomes: patients with more severe injury at admission presented poor neurological outcomes. Intramedullary magnetic resonance imaging signal abnormalities were also associated with neurological outcomes, as the presence of intramedullary hemorrhage was a factor of poor prognosis. Other largely studied predictors, such as age and surgical timing, showed some inconsistency in results depending on cutoffs. Younger age and early surgery were generally associated with good outcomes. Although widely studied, other factors, such as vertebral and associated injuries, failed to show association with outcomes. Cerebrospinal fluid inflammatory biomarkers, as emerging factors, were significantly associated with outcomes.

CONCLUSIONS

This study provides a comprehensive review of predictors of neurological outcomes after traumatic spinal cord injury. It also highlights the heterogeneity of outcomes used by studies to assess neurological recovery. The proposed conceptual framework classifies predictors and illustrates their relationships with outcomes.

Improving Diagnostic Workup Following Traumatic Spinal Cord Injury: Advances in Biomarkers

PURPOSE OF REVIEW

Traumatic spinal cord injury (SCI) is a life-changing event with drastic implications for patients due to sensorimotor impairment and autonomous dysfunction. Current clinical evaluations focus on the assessment of injury level and severity using standardized neurological examinations. However, they fail to predict individual trajectories of recovery, which highlights the need for the development of advanced diagnostics. This narrative review identifies recent advances in the search of clinically relevant biomarkers in the field of SCI.

RECENT FINDINGS

Advanced neuroimaging and molecular biomarkers sensitive to the disease processes initiated by the SCI have been identified. These biomarkers range from advanced neuroimaging techniques, neurophysiological readouts, and molecular biomarkers identifying the concentrations of several proteins in blood and CSF samples. Some of these biomarkers improve current prediction models based on clinical readouts. Validation with larger patient cohorts is warranted. Several biomarkers have been identified-ranging from imaging to molecular markers-that could serve as advanced diagnostic and hence supplement current clinical assessments.

Blood Serum Cytokines in Patients with Subacute Spinal Cord Injury: A Pilot Study to Search for Biomarkers of Injury Severity

Background. Despite considerable interest in the search for a spinal cord injury (SCI) therapy, there is a critical need to develop a panel of diagnostic biomarkers to determine injury severity. In this regard, there is a requirement for continuing research into the fundamental processes of neuroinflammatory and autoimmune reactions in SCI, identifying changes in the expression of cytokines. Methods. In this pilot study, an extended multiplex analysis of the cytokine profiles in the serum of patients at 2 weeks post-SCI (n = 28) was carried out, together with an additional assessment of neuron-specific enolase (NSE) and vascular endothelial growth factor (VEGF) levels by enzyme-linked immunosorbent assay. A total of 16 uninjured subjects were enrolled as controls. Results. The data obtained showed a large elevation of IFNγ (>52 fold), CCL27 (>13 fold), and CCL26 (>8 fold) 2 weeks after SCI. The levels of cytokines CXCL5, CCL11, CXCL11, IL10, TNFα, and MIF were different between patients with baseline American Spinal Injury Association Impairment Scale (AIS) grades of A or B, whilst IL2 (>2 fold) and MIP-3a (>6 fold) were significantly expressed in the cervical and thoracic regions. There was a trend towards increasing levels of NSE. However, the difference in NSE was lost when the patient set was segregated based on AIS group. Conclusions. Our pilot research demonstrates that serum concentrations of cytokines can be used as an affordable and rapid detection tool to accurately stratify SCI severity in patients.

Trends in Rates of ASIA Impairment Scale Conversion in Traumatic Complete Spinal Cord Injury

Recent studies of persons with spinal cord injury (SCI) report higher conversion rates of the American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades, especially for complete injuries. We examined the rate of conversion over time after complete SCI, accounting for demographic and injury characteristics. Subjects were 16 years of age and older with a complete SCI injury between 1995 and 2015, enrolled in the National SCI Database as day-1 admissions. We grouped subjects into 3-year intervals and assessed trends in conversion for the total sample and by tetraplegia (Tetra), high paraplegia (levels T1–9, HPara), and low paraplegia (levels T10–12, LPara).We used logistic regression to identify factors related to conversion such as age, sex, etiology, and level of injury. Of 2036 subjects, 1876 subjects had a follow-up examination between 30 and 730 days post-injury. Average age at injury was 34.2 ± 14.6 years; 79.8% were male, 44.6% Tetra, 35.3% HPara, and 20.1% LPara. There was a strong trend toward increased rates of conversion over time (p < 0.01 for all groups), especially for Tetra (to incomplete from 17.6% in 1995–1997 to 50% in 2013–2015, and to motor incomplete from 9.4% to 28.1%). Conversion rates for Para were less dramatic. There were increased odds of converting to incomplete for year of injury, level of injury (Tetra >LPara >HPara), non-violent etiology, and age (older is better). We found similar factors for conversion to motor incomplete, except sex was significant and etiology was not. Conversion rates from complete to incomplete and motor incomplete injury have been increasing, particularly for persons with tetraplegia. This has implications for acute clinical trials and for prognostication early after SCI.

Biomarkers in Traumatic Spinal Cord Injury—Technical and Clinical Considerations: A Systematic Review

Objective. To examine (1) if serological or cerebrospinal fluid (CSF) biomarkers can be used as diagnostic and/or prognostic tools in patients with spinal cord injury (SCI) and (2) if literature provides recommendations regarding timing and source of biomarker evaluation. Data Sources. A systematic literature search to identify studies reporting on diagnostic and prognostic blood and/or CSF biomarkers in SCI was conducted in PubMed/MEDLINE, CINAHL, Science Direct, The Cochrane Library, ISI Web of Science, and PEDro. Study Selection. Clinical trials, cohort, and pilot studies on patients with traumatic SCI investigating at least one blood or CSF biomarker were included. Following systematic screening, 19 articles were included in the final analysis. PRISMA guidelines were followed to conduct this review. Data Extraction. Independent extraction of articles was completed by 2 authors using predefined inclusion criteria and study quality indicators. Data Synthesis. Nineteen studies published between 2002 and April 2019 with 1596 patients were included in the systematic review. In 14 studies, blood biomarkers were measured, 4 studies investigated CSF biomarkers, and 1 study used both blood and CSF samples. Conclusions. Serum/CSF concentrations of several biomarkers (S100b, IL-6, GFAP, NSE, tau, TNF-α, IL-8, MCP-1, pNF-H, and IP-10) following SCI are highly time dependent and related to injury severity. Future studies need to validate these markers as true biomarkers and should control for secondary complications associated with SCI. A deeper understanding of secondary pathophysiological events after SCI and their effect on biomarker dynamics may improve their clinical significance as surrogate parameters in future clinical studies.

Practical Application of Recent Advances in Diagnostic, Prognostic, and Therapeutic Modalities for Spinal Cord Injury

OBJECTIVE

Spinal cord injury remains a highly morbid entity, with limited treatment modalities in both acute and chronic settings. Clinical research efforts to improve therapeutic guidelines are confounded by initial evaluation inaccuracies, as presentations are frequently complicated by trauma and objective diagnostic and prognostic methods are poorly defined. The purpose of our study was to review recent practical advances for further delineation of these injuries and how such classification may benefit the development of novel treatments.

METHODS

A review was carried out of recent studies reported within the last 5 years for prognostic and diagnostic modalities of acute spinal cord injury.

RESULTS

Substantial efforts have been made to improve the timeliness and accuracy of the initial assessment, not only for the purpose of enhancing prognostication but also in determining the efficacy of new treatments. Whether it be applying traumatic brain injury principles to limit injury extent, external stimulators used for chronic pain conditions to enhance the effects of physical therapy, or creative algorithms incorporating various nerve or muscle transfer techniques, innovative and practical solutions continue to be developed in lieu of definitive treatment. Further development will benefit from enhanced stratification of injury from accurate and practical assessment modalities.

CONCLUSIONS

Recent advances in accurate, timely, and practical classification methods of acute spinal cord injury will assist in the development of novel treatment approaches for both acute and chronic injury alike.