A Review of Clinical Trials in Spinal Cord Injury Including Biomarkers

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.

Steroid inhibited Serpina3n expression which was positively correlated with the degrees of spinal cord injury

Aims

The aim of our project was to identify proteins associated with the extent of spinal cord injury (SCI) and subsequent long-term neurological recovery.

Methods

Through proteomic analysis, we identified proteins that are differentially expressed specifically in the acute phase of injury. We analyzed the concentrations of differentially expressed proteins in serum and the injured spinal cord segment by ELISA.

Results

Serpina3n protein expression in the injured spinal cord segment was increased 101-fold at 12 h after severe SCI and 89-fold at 12 h after mild SCI, as determined by LC‒MS/MS. In the mild and severe SCI groups, serum Serpina3n levels began to increase at 12 h and peaked at 24 h. At 12 h, 24 h and 3 d after injury, serum Serpina3n protein levels were significantly correlated with the severity of injury (12 h: r = 0.6034, P = 0.008; 24 h: r = 0.7542, P = 0.0003; 3 d: r = 0.862, P < 0.001). Serum Serpina3n levels at 2 h, 24 h and 3 d post injury were significantly correlated with long-term neurological recovery at 28 d after SCI (2 h: r = -0.5781, P = 0.012; 24 h: r = -0.5912, P = 0.0098; 3 d: r = -0.7792, P < 0.0001). Methylprednisolone treatment would decrease the serum Serpina3n levels in mice with mild and severe SCI compared with those in placebo-group mice at 12 h and 24 h after SCI. The serum Serpina3n concentration in the severe SCI group was significantly reduced on the third day after steroid treatment.

Conclusion

Taken together, these data suggest that serpina3n may be a circulating biomarker of acute SCI and may be closely associated with injury severity and long-term motor function recovery.

Riluzole in Spinal Cord Injury Study (RISCIS)-Pharmacokinetic (PK) Sub-Study: An Analysis of Pharmacokinetics, Pharmacodynamics, and Impact on Axonal Degradation of Riluzole in Patients With Traumatic Cervical Spinal Cord Injury Enrolled in the RISCIS Phase III Randomized Controlled Trial

To date, no drug therapy has shown significant efficacy in improving functional outcomes in patients with acute spinal cord injury (SCI). Riluzole is an approved benzothiazole sodium channel blocker to attenuate neurodegeneration in amyotrophic lateral sclerosis (ALS) and is of interest for neuroprotection in SCI. In a Phase I clinical trial (ClinicalTrials.gov Identifier: NCT00876889), riluzole was well tolerated with a 2-week treatment at the dose level approved for ALS and exhibited potential efficacy in patients with SCI. The acute and progressive nature of traumatic SCI and the complexity of secondary injury processes alter the pharmacokinetics (PK) of therapeutics. In the PK sub-study of the multi-center, randomized, placebo-controlled, double-blinded Riluzole in Spinal Cord Injury Study (RISCIS) Phase II/III trial (ClinicalTrials.gov Identifier: NCT01597518), a total of 32 SCI patients were enrolled, and most of our patients were middle-age Caucasian males with head and neck injuries. We studied the PK and pharmacodynamics (PD) of riluzole on motor recovery, measured by International Standards for Neurological Classification of SCI (ISNCSCI) Motor Score at injury and at 3-month and 6-month follow-ups, along with levels of the axonal injury biomarker phosphorylated neurofilament heavy chain (pNF-H), during the 2-week treatment. PK modeling, PK/PD correlations were developed to identify the potential effective exposure of riluzole for intended PD outcomes. The longitudinal impacts of SCI on the PK of riluzole are characterized. A time-varying population PK model of riluzole is established, incorporating time-varying clearance and volume of distribution from combined data of Phase I and Phase II/III trials. With the developed model, a rational, optimal dosing scheme can be designed with time-dependent modification to preserve the required therapeutic exposure of riluzole. The PD of riluzole and the relationship between PK and neurological outcomes of the treatment were established. The time course of efficacy in total motor score improvement (ΔTMS) and pNF-H were monitored. A three-dimensional (3D) PK/PD correlation was established for ΔTMS at 6 months with overall riluzole exposure area under the curve for Day 0-Day14 (AUCD0-D14) and baseline TMS for individual patients. Patients with baseline TMS between 1 and 36 benefited from the optimal exposure range of 16-48 mg*h/mL. The PD models of pNF-H revealed the riluzole efficacy, as treated subjects exhibited a diminished increase in progression of pNF-H, indicative of reduced axonal breakdown. The independent parameter of area between effective curves (ABEC) between the time profiles of pNF-H in placebo and treatment groups was statistically identified as a significant predictor for the treatment effect on the biomarker. A mechanistic clinical outcomes (CO)/PD (pNF-H) model was established, and the proposed structure demonstrated the feasibility of PK/PD/CO correlation model. No appreciable hepatic toxicity was observed with the current riluzole treatment regimen. The development of effective treatment for SCI is challenging. However, the future model-informed and PK-guided drug development and regimen modification can be rationally executed with the optimal dosing regimen design based on the developed 3D PK/PD model. The PK/PD/CO model can serve as a rational guide for future drug development, PKPD model refinement, and extension to other studies in SCI settings.

Current Concepts of Biomaterial Scaffolds and Regenerative Therapy for Spinal Cord Injury

Spinal cord injury (SCI) is a catastrophic condition associated with significant neurological deficit and social and financial burdens. It is currently being managed symptomatically, with no real therapeutic strategies available. In recent years, a number of innovative regenerative strategies have emerged and have been continuously investigated in preclinical research and clinical trials. In the near future, several more are expected to come down the translational pipeline. Among ongoing and completed trials are those reporting the use of biomaterial scaffolds. The advancements in biomaterial technology, combined with stem cell therapy or other regenerative therapy, can now accelerate the progress of promising novel therapeutic strategies from bench to bedside. Various types of approaches to regeneration therapy for SCI have been combined with the use of supportive biomaterial scaffolds as a drug and cell delivery system to facilitate favorable cell-material interactions and the supportive effect of neuroprotection. In this review, we summarize some of the most recent insights of preclinical and clinical studies using biomaterial scaffolds in regenerative therapy for SCI and summarized the biomaterial strategies for treatment with simplified results data. One hundred and sixty-eight articles were selected in the present review, in which we focused on biomaterial scaffolds. We conducted our search of articles using PubMed and Medline, a medical database. We used a combination of "Spinal cord injury" and ["Biomaterial", or "Scaffold"] as search terms and searched articles published up until 30 April 2022. Successful future therapies will require these biomaterial scaffolds and other synergistic approaches to address the persistent barriers to regeneration, including glial scarring, the loss of a structural framework, and biocompatibility. This database could serve as a benchmark to progress in future clinical trials for SCI using biomaterial scaffolds.

Advantages and Limitations in the Evaluation of the Neurological and Functional Deficit in Patients with Spinal Cord Injuries

(1) Background: Vertebro-medullary trauma (VMT) causes osteo-articular injuries in a varied anatomical lesion associated with multiple clinical manifestations and therapeutic indications. The neurological evaluation of patients who have suffered a spinal cord injury (SCI) is costly in testing the motor and sensory function. To standardize the assessment, several scales are used that measure the neurological deficit in order to guide subsequent treatment according to complete or incomplete SCI. The aim of this study is to identify and present the relevant tools for assessing SCI. (2) Methods: Relevant SCI studies were used for a fact-finding investigation from a rational and critical perspective of this field of research. The relationship between clinical tools and those with a psychosocial component was assessed based on studies reported in the literature. (3) Results: SCI severity scales have been proposed throughout to be able to estimate the functional prognosis of victims of these traumatic events. These tools can be divided into scales for assessing the neurological deficit due to trauma, and functional scales that assess the ability to perform daily activities, self-care, etc. (4) Conclusions: The closest scale to the need for standardization and the most accurate assessment of neurological deficits secondary to SCI is ASIA/IMSOP.

The trajectory of serum levels of glial fibrillary acidic protein within four weeks post-injury is related to neurological recovery during the transition from acute to chronic spinal cord injury

The use of biomarkers in spinal cord injury (SCI) research has evolved rapidly in recent years whereby most studies focused on the acute post-injury phase. Since SCI is characterized by persisting neurological impairments, the question arises whether blood biomarkers remain altered during the subacute post-injury time. Sample collection in the subacute phase might provide a better insight in the ongoing SCI specific molecular mechanism with fewer confounding factors compared to the acute phase where, amongst other complications, individuals receive a substantial amount of medication. This study aimed to determine if the temporal dynamics of serum biomarkers of neurodegeneration differ between individuals depending on their extent of neurological recovery in the transition phase between acute and chronic SCI. We performed a secondary analysis of biomarkers in patients with SCI (n=41) who were treated at a level I trauma center in Germany. Patients with cervical or thoracic SCI regardless of injury severity were included. Blood samples were collected in the acute phase (1-4 days post-injury), and after 30- and 120-days post-injury. Serum protein levels of Glial Fibrillary Acidic Protein (GFAP), and Neurofilament light protein (NfL) were determined for each time point of sample collection using R-Plex Assays (Meso Scale Discovery). Linear mixed models were used to evaluate the trajectory of GFAP and NfL over time. Fixed effects of time, neurological recovery, and injury severity along with the recovery-by-time interaction were included in models with random slopes and intercepts. GFAP levels increase during the first days after SCI and decrease in subacute to chronic stages. Notably, the trajectory of GFAP over time is significantly associated with the extent of neurological recovery during the transition from acute to chronic SCI with a steeper decline in individuals who recovered better. Serum levels of NfL continue to rise significantly until day 30 followed by a decrease afterwards, independent of neurological recovery. The trajectory of serum GFAP levels qualifies as a prognostic biomarker for neurological recovery, and facilitates monitoring of disease progression in the sub-acute post-injury phase.

Translational PET Imaging of Spinal Cord Injury with the Serotonin Transporter Tracer [11C]AFM

PURPOSE

The descending raphespinal serotonin (5-HT) system contributes to neural activities required for locomotion. The presynaptic serotonin transporter (SERT) is a marker of 5-HT innervation. In this study, we explored the use of PET imaging with the SERT radioligand [¹¹C]AFM as a biomarker of 5-HT axon damage after spinal cord injury (SCI) in a rodent model and its translation to imaging SCI in humans.

PROCEDURES

PET imaging with [¹¹C]AFM was performed in healthy rats under baseline and citalopram blocking conditions and a mid-thoracic transection rat model of SCI. The lumbar-to-cervical activity (L/C) ratio was calculated for the healthy and SCI animals to assess SERT binding decrease after SCI. Finally, translation of [¹¹C]AFM PET was attempted to explore its potential to image SCI in humans.

RESULTS

Intense uptake in the brain and intact spinal cord was observed at 30-60 min post-injection of [¹¹C]AFM in healthy rats. About 65% of [¹¹C]AFM uptake in the spinal cord was blocked by citalopram. In the SCI rat model, the cervical uptake of [¹¹C]AFM was similar to that in healthy rats, but the lumbar uptake was dramatically reduced, resulting in about half the L/C ratio in SCI rats compared to healthy rats. In contrast, [¹¹C]AFM uptake in the human spinal cord showed no obvious decrease after treatment with citalopram. In the human subjects with SCI, decreases in [¹¹C]AFM uptake were also not obvious in the section of spinal cord caudal to the injury point.

CONCLUSION

[¹¹C]AFM PET imaging of SERT provides a useful preclinical method to non-invasively visualize the rodent spinal cord and detect SERT changes in SCI rodent models. However, there appears to be little detectable specific binding signal for [¹¹C]AFM in the human spinal cord. An SERT tracer with higher affinity and lower non-specific binding signal is needed to image the spinal cord in humans and to assess the axonal status in SCI patients.

Diffusional kurtosis imaging as a possible prognostic marker of cervical incomplete spinal cord injury outcome: a prospective pilot study

BACKGROUND

Spinal cord injury (SCI) is associated with substantial chronic morbidity and mortality. Routine imaging techniques such as T1- and T2-weighted magnetic resonance imaging (MRI) are not effective in predicting neurological deficiency grade or outcome. Diffusional kurtosis imaging (DKI) is an MR imaging technique that provides microstructural information about biological tissue. There are no longitudinal prospective studies assessing DKI metrics in acute traumatic SCI. Therefore, the purpose of this study was to establish a DKI protocol for acute SCI and correlate the DKI metrics to the functional neurological outcome of the patients.

METHODS

Eight consecutive SCI patients referred to our institution with cervical SCI were included in the study. An acute diagnostic MRI scan was supplemented with a novel fast, mean kurtosis DKI protocol, which describes the average deviation from Gaussian diffusional along nine different directions. Mean kurtosis values were measured at the injury site and normalized to the mean kurtosis values of a non-injured site. At discharge form specialized rehabilitation, patients were evaluated using the Spinal Cord Independence Measure-III (SCIM-III). The DKI metrics and SCIM-III were analysed using Spearman's rank correlation.

RESULTS

This pilot study found a significant correlation between decreasing mean kurtosis values at the injury site of the spinal cord and higher grade of disability measured by the SCIM-III (p = 0.002).

CONCLUSION

This pilot study found that DKI may be a valuable tool as a prognostic marker in the acute phase of SCI.

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.

Natural Progression of Routine Laboratory Markers after Spinal Trauma: A Longitudinal, Multi-Cohort Study

Our objective was to track and quantify the natural course of serological markers over the 1st year following spinal cord injury. For that purpose, data on serological markers, demographics, and injury characteristics were extracted from medical records of a clinical trial (Sygen) and an ongoing observational cohort study (Murnau study). The primary outcomes were concentration/levels/amount of commonly collected serological markers at multiple time points. Two-way analysis of variance (ANOVA) and mixed-effects regression techniques were used to account for the longitudinal data and adjust for potential confounders. Trajectories of serological markers contained in both data sources were compared using the slope of progression. Our results show that, at baseline (≤ 2 weeks post-injury), most serological markers were at pathological levels, but returned to normal values over the course of 6-12 months post-injury. The baseline levels and longitudinal trajectories were dependent on injury severity. More complete injuries were associated with more pathological values (e.g., hematocrit, ANOVA test; χ2 = 68.93, df = 3, adjusted p value <0.001, and χ2 = 73.80, df = 3, adjusted p value <0.001, in the Sygen and Murnau studies, respectively). Comparing the two databases revealed some differences in the serological markers, which are likely attributable to differences in study design, sample size, and standard of care. We conclude that because of trauma-induced physiological perturbations, serological markers undergo marked changes over the course of recovery, from initial pathological levels that normalize within a year. The findings from this study are important, as they provide a benchmark for clinical decision making and prospective clinical trials. All results can be interactively explored on the Haemosurveillance web site (https://jutzelec.shinyapps.io/Haemosurveillance/) and GitHub repository (https://github.com/jutzca/Systemic-effects-of-Spinal-Cord-Injury).

Characterization of Cerebrospinal Fluid Ubiquitin C-Terminal Hydrolase L1 as a Biomarker of Human Acute Traumatic Spinal Cord Injury

A major obstacle for translational research in acute spinal cord injury (SCI) is the lack of biomarkers that can objectively stratify injury severity and predict outcome. Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a neuron-specific enzyme that shows promise as a diagnostic biomarker in traumatic brain injury (TBI), but has not been studied in SCI. In this study, cerebrospinal fluid (CSF) and serum samples were collected over the first 72-96 h post-injury from 32 acute SCI patients who were followed prospectively to determine neurological outcomes at 6 months post-injury. UCH-L1 concentration was measured using the Quanterix Simoa platform (Quanterix, Billerica, MA) and correlated to injury severity, time, and neurological recovery. We found that CSF UCH-L1 was significantly elevated by 10- to 100-fold over laminectomy controls in an injury severity- and time-dependent manner. Twenty-four-hour post-injury CSF UCH-L1 concentrations distinguished between American Spinal Injury Association Impairment Scale (AIS) A and AIS B, and AIS A and AIS C patients in the acute setting, and predicted who would remain "motor complete" (AIS A/B) at 6 months with a sensitivity of 100% and a specificity of 86%. AIS A patients who did not improve their AIS grade at 6 months post-injury were characterized by sustained elevations in CSF UCH-L1 up to 96 h. Similarly, the failure to gain >8 points on the total motor score at 6 months post-injury was associated with higher 24-h CSF UCH-L1. Unfortunately, serum UCH-L1 levels were not informative about injury severity or outcome. In conclusion, CSF UCH-L1 in acute SCI shows promise as a biomarker to reflect injury severity and predict outcome.

Dynamics of Selected Biomarkers in Cerebrospinal Fluid During Complex Endovascular Aortic Repair - A Pilot Study

INTRODUCTION

Ischemic spinal cord injury (SCI) is a serious complication of complex aortic repair. Prophylactic cerebrospinal fluid (CSF) drainage, used to decrease lumbar cerebrospinal fluid (CSF) pressure, enables monitoring of CSF biomarkers that may aid in detecting impending SCI. We hypothesized that biomarkers, previously evaluated in traumatic SCI and brain injury, would be altered in CSF over time following complex endovascular aortic repair (cEVAR).

OBJECTIVES

To examine if a chosen cohort of CSF biomarker correlates to SCI and warrants further research.

METHODS

A prospective observational study on patients undergoing cEVAR with extensive aortic coverage. Vital parameters and CSF samples were collected on ten occasions during 72 hours post-surgery. A panel of ten biomarkers were analyzed (Neurofilament Light Polypeptide (NFL), Tau, Glial Fibrillary Acidic Protein (GFAP), Soluble Amyloid Precursos Protein (APP) α and β, Amyloid β 38, 40 and 42 (Aβ38, 40 and 42), Chitinase-3-like protein 1 (CHI3LI or YKL-40), Heart-type fatty acid binding protein (H-FABP).).

RESULTS

Nine patients (mean age 69, 7 males) were included. Median total aortic coverage was 68% [33, 98]. One patient died during the 30-day post-operative period. After an initial stable phase for the first few postoperative hours, most biomarkers showed an upward trend compared with baseline in all patients with >50% increase in value for NFL in 5/9 patients, in 7/9 patients for Tau and in 5/9 patients for GFAP. One patient developed spinal cord and supratentorial brain ischemia, confirmed with MRI. In this case, NF-L, GFAP and tau were markedly elevated compared with non-SCI patients (maximum increase compared with baseline in the SCI patient versus mean value of the maximal increase for all other patients: NF-L 367% vs 79%%, GFAP 95608% versus 3433%, tau 1020% vs 192%).

CONCLUSION

This study suggests an increase in all ten studied CSF biomarkers after coverage of spinal arteries during endovascular aortic repair. However, the pilot study was not able to establish a specific correlation between spinal fluid biomarker elevation and clinical symptoms of SCI due to small sample size and event rate.

Ultrasound in Traumatic Spinal Cord Injury: A Wide-Open Field

Traumatic spinal cord injury (SCI) is a common and devastating condition. In the absence of effective validated therapies, there is an urgent need for novel methods to achieve injury stabilization, regeneration, and functional restoration in SCI patients. Ultrasound is a versatile platform technology that can provide a foundation for viable diagnostic and therapeutic interventions in SCI. In particular, real-time perfusion and inflammatory biomarker monitoring, focal pharmaceutical delivery, and neuromodulation are capabilities that can be harnessed to advance our knowledge of SCI pathophysiology and to develop novel management and treatment options. Our review suggests that studies that evaluate the benefits and risks of ultrasound in SCI are severely lacking and our understanding of the technology's potential impact remains poorly understood. Although the complex anatomy and physiology of the spine and the spinal cord remain significant challenges, continued technological advances will help the field overcome the current barriers and bring ultrasound to the forefront of SCI research and development.

Acute spinal cord injury: Pathophysiology and pharmacological intervention (Review)

Spinal cord injury (SCI) is one of the most debilitating of all the traumatic conditions that afflict individuals. For a number of years, extensive studies have been conducted to clarify the molecular mechanisms of SCI. Experimental and clinical studies have indicated that two phases, primary damage and secondary damage, are involved in SCI. The initial mechanical damage is caused by local impairment of the spinal cord. In addition, the fundamental mechanisms are associated with hyperflexion, hyperextension, axial loading and rotation. By contrast, secondary injury mechanisms are led by systemic and cellular factors, which may also be initiated by the primary injury. Although significant advances in supportive care have improved clinical outcomes in recent years, a number of studies continue to explore specific pharmacological therapies to minimize SCI. The present review summarized some important pathophysiologic mechanisms that are involved in SCI and focused on several pharmacological and non‑pharmacological therapies, which have either been previously investigated or have a potential in the management of this debilitating injury in the near future.

Traumatic Spinal Cord Disorders: Current Topics and Future Directions

Traumatic spinal cord injury (tSCI) is a life-changing and potentially overwhelming event. The sudden disruption of the spinal cord's integrity necessitates rapid attention at a specialized medical center, and involves a multilateral collaboration between neurologists, spine surgeons, critical care physicians, and trauma specialists. Even with care under ideal conditions, many tSCI patients have significant disability that persists for the rest of their lives. However, recently, we have seen a proliferation in clinical and translational trials that offer the promise that new treatments may be available soon.

Prelude to the special issue on novel neurocircuit, cellular and molecular targets for developing functional rehabilitation therapies of neurotrauma

The poor endogenous recovery capacity and other impediments to reinstating sensorimotor or autonomic function after adult neurotrauma have perplexed modern neuroscientists, bioengineers, and physicians for over a century. However, despite limited improvement in options to mitigate acute pathophysiological sequalae, the past 20 years have witnessed marked progresses in developing efficacious rehabilitation strategies for chronic spinal cord and brain injuries. The achievement is mainly attributable to research advancements in elucidating neuroplastic mechanisms for the potential to enhance clinical prognosis. Innovative cross-disciplinary studies have established novel therapeutic targets, theoretical frameworks, and regiments to attain treatment efficacy. This Special Issue contained eight papers that described experimental and human data along with literature reviews regarding the essential roles of the conventionally undervalued factors in neural repair: systemic inflammation, neural-respiratory inflammasome axis, modulation of glutamatergic and monoaminergic neurotransmission, neurogenesis, nerve transfer, recovery neurobiology components, and the spinal cord learning, respiration and central pattern generator neurocircuits. The focus of this work was on how to induce functional recovery from manipulating these underpinnings through their interactions with secondary injury events, peripheral and supraspinal inputs, neuromusculoskeletal network, and interventions (i.e., activity training, pharmacological adjuncts, electrical stimulation, and multimodal neuromechanical, brain-computer interface [BCI] and robotic assistance [RA] devices). The evidence suggested that if key neurocircuits are therapeutically reactivated, rebuilt, and/or modulated under proper sensory feedback, neurological function (e.g., cognition, respiration, limb movement, locomotion, etc.) will likely be reanimated after neurotrauma. The efficacy can be optimized by individualizing multimodal rehabilitation treatments via BCI/RA-integrated drug administration and neuromechanical protheses.

Routine Blood Chemistry Predicts Functional Recovery After Traumatic Spinal Cord Injury: A Post Hoc Analysis

BACKGROUND

Spinal cord injury (SCI) leads to various degrees of lifelong functional deficits. Most individuals with incomplete SCI experience a certain degree of functional recovery, especially within the first-year postinjury. However, this is difficult to predict, and surrogate biomarkers are urgently needed.

OBJECTIVE

We aimed to (1) determine if routine blood chemistry parameters are related to neurological recovery after SCI, (2) evaluate if such parameters could predict functional recovery, and (3) establish cutoff values that could inform clinical decision-making.

METHODS

We performed a post hoc analysis of routine blood chemistry parameters in patients with traumatic SCI (n = 676). Blood samples were collected between 24 and 72 hours as well as at 1, 2, 4, 8, and 52 weeks postinjury. Linear mixed models, regression analysis, and unbiased recursive partitioning (URP) of blood chemistry data were used to relate to and predict walking recovery 1 year postinjury.

RESULTS

The temporal profile of platelet counts and serum levels of albumin, alkaline phosphatase, and creatinine differentiated patients who recovered walking from those who remained wheelchair bound. The 4 blood chemistry parameters from the sample collection 8 weeks postinjury predicted functional recovery observed 1 year after incomplete SCI. Finally, URP defined a cutoff for serum albumin at 3.7 g/dL, which in combination with baseline injury severity differentiates individuals who regain ambulation from those not able to walk. Specifically, about 80% of those with albumin >3.7 g/dL recovered walking.

CONCLUSIONS

Routine blood chemistry data from the postacute phase, together with baseline injury severity, predict functional outcome after incomplete SCI.

Targeting axon guidance cues for neural circuit repair after spinal cord injury

At least two-thirds of spinal cord injury cases are anatomically incomplete, without complete spinal cord transection, although the initial injuries cause complete loss of sensory and motor functions. The malleability of neural circuits and networks allows varied extend of functional restoration in some individuals after successful rehabilitative training. However, in most cases, the efficiency and extent are both limited and uncertain, largely due to the many obstacles of repair. The restoration of function after anatomically incomplete injury is in part made possible by the growth of new axons or new axon branches through the spared spinal cord tissue and the new synaptic connections they make, either along the areas they grow through or in the areas they terminate. This review will discuss new progress on the understanding of the role of axon guidance molecules, particularly the Wnt family proteins, in spinal cord injury and how the knowledge and tools of axon guidance can be applied to increase the potential of recovery. These strategies, combined with others, such as neuroprotection and rehabilitation, may bring new promises. The recovery strategies for anatomically incomplete spinal cord injuries are relevant and may be applicable to traumatic brain injury and stroke.

Traumatic Injuries to the Spinal Cord and Peripheral Nervous System

Both blunt and penetrating trauma can cause injuries to the peripheral and central nervous systems. Emergency providers must maintain a high index of suspicion, especially in the setting of polytrauma. There are 2 major classifications of peripheral nerve injuries (PNIs). Some PNIs are classically associated with certain traumatic mechanisms. Most closed PNIs are managed conservatively, whereas sharp nerve transections require specialist consultation for urgent repair. Spinal cord injuries almost universally require computed tomography imaging; some require emergent magnetic resonance imaging. Providers should work to minimize secondary injury. Surgical specialists are needed for closed reduction, surgical decompression, or stabilization.

Factors related to improved American Spinal Injury Association grade of acute traumatic spinal cord injury

BACKGROUND

Acute traumatic spinal cord injury (ATSCI) usually results in disability, yet data on contemporary national trends of ATSCI incidence are limited.

AIM

To provide a systematic and basic theoretical basis for improving the treatment of acute spinal cord injury.

METHODS

Data from the Peking University Third Hospital Inpatient Sample databases were analyzed. A total of 304 patients with ATSCI were included from 2012 to 2017. The epidemiological data, treatment, complications and clinical outcomes of these patients were reviewed.

RESULTS

Of the 304 patients, 257 (84.5%) were male, and 75% of the patients were 55 years old or younger. 135 patients had improved follow-up American Spinal Injury Association (ASIA) grades (44.4%). Only 14 patients with ASIA grade A improved. A statistically significant difference in prognosis between patients who underwent surgery within 72 h and those who underwent surgery after 72 h was observed (P < 0.05). Surgery within 72 h resulted in better prognosis. The Steroid group and the Non-Steroid group showed a significant difference in outcome among patients with ASIA grades A and B (P < 0.05). Patients with pneumonia had a poorer prognosis than patients without pneumonia (P < 0.05). Surgery within 72 h resulted in better prognosis.

CONCLUSION

This study found that there was no significant difference in hospitalization time and prognosis between the Steroid group and the Non-Steroid group, but the patients with severe spinal cord injury (ASIA grades A and B) who underwent surgery combined with steroid therapy had a better prognosis than those who underwent surgery alone. The disastrous consequences of ATSCI and lack of consensus on the management strategy are obvious. Further improvements in treatment planns are needed in order to obtain more reliable functional outcomes.

Neuroinflammation Treatment via Targeted Delivery of Nanoparticles

The lack of effective treatments for most neurological diseases has prompted the search for novel therapeutic options. Interestingly, neuroinflammation is emerging as a common feature to target in most CNS pathologies. Recent studies suggest that targeted delivery of small molecules to reduce neuroinflammation can be beneficial. However, suboptimal drug delivery to the CNS is a major barrier to modulate inflammation because neurotherapeutic compounds are currently being delivered systemically without spatial or temporal control. Emerging nanomaterial technologies are providing promising and superior tools to effectively access neuropathological tissue in a controlled manner. Here we highlight recent advances in nanomaterial technologies for drug delivery to the CNS. We propose that state-of-the-art nanoparticle drug delivery platforms can significantly impact local CNS bioavailability of pharmacological compounds and treat neurological diseases.

A Randomized Controlled Trial of Early versus Late Surgical Decompression for Thoracic and Thoracolumbar Spinal Cord Injury in 73 Patients

Convincing clinical evidence exists to support early surgical decompression in the setting of cervical spinal cord injury (SCI). However, clinical evidence on the effect of early surgery in patients with thoracic and thoracolumbar (from T1 to L1 [T1–L1]) SCI is lacking and a critical knowledge gap remains. This randomized controlled trial (RCT) sought to evaluate the safety and efficacy of early (<24 h) compared with late (24–72 h) decompressive surgery after T1–L1 SCI. From 2010 to 2018, patients (≥16 years of age) with acute T1–L1 SCI presenting to a single trauma center were randomized to receive either early (<24 h) or late (24–72 h) surgical decompression. The primary outcome was an ordinal change in American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade at 12-month follow-up. Secondary outcomes included complications and change in ASIA motor score (AMS) at 12 months. Outcome assessors were blinded to treatment assignment.

Of 73 individuals whose treatment followed the study protocol, 37 received early surgery and 36 underwent late surgery. The mean age was 29.74 ± 11.4 years. In the early group 45.9% of patients and in the late group 33.3% of patients had a ≥1-grade improvement in AIS (odds ratio [OR] 1.70, 95% confidence interval [CI]: 0.66-4.39, p = 0.271); significantly more patients in the early (24.3%) than late (5.6%) surgery group had a ≥2-grade improvement in AIS (OR 5.46, 95% CI: 1.09-27.38, p = 0.025). There was no statistically significant difference in the secondary outcome measures. Surgical decompression within 24 h of acute traumatic T1–L1 SCI is safe and is associated with improved neurological outcome, defined as at least a 2-grade improvement in AIS at 12 months.

A Guide to Extract Spinal Cord for Translational Stem Cell Biology Research: Comparative Analysis of Adult Human, Porcine, and Rodent Spinal Cord Stem Cells

Improving the clinical translation of animal-based neural stem/progenitor cell (NSPC) therapies to humans requires an understanding of intrinsic human and animal cell characteristics. We report a novel in vitro method to assess spinal cord NSPCs from a small (rodent) and large (porcine) animal model in comparison to human NSPCs. To extract live adult human, porcine, and rodent spinal cord tissue, we illustrate a strategy using an anterior or posterior approach that was simulated in a porcine model. The initial expansion of primary NSPCs is carried out using the neurosphere assay followed by a pharmacological treatment phase during which NSPCs derived from humans, porcines, and rodents are assessed in parallel using the same defined parameters. Using this model, NSPCs from all species demonstrated multi-lineage differentiation and self-renewal. Importantly, these methods provide conditions to enable the direct comparison of species-dependent cell behavior in response to specific exogenous signals.

Chronic Pain After Spinal Cord Injury: Is There a Role for Neuron-Immune Dysregulation?

Spinal cord injury (SCI) is a devastating event with a tremendous impact in the life of the affected individual and family. Traumatic injuries related to motor vehicle accidents, falls, sports, and violence are the most common causes. The majority of spinal lesions is incomplete and occurs at cervical levels of the cord, causing a disruption of several ascending and descending neuronal pathways. Additionally, many patients develop chronic pain and describe it as burning, stabbing, shooting, or shocking and often arising with no stimulus. Less frequently, people with SCI also experience pain out of context with the stimulus (e.g., light touch). While abolishment of the endogenous descending inhibitory circuits is a recognized cause for chronic pain, an increasing number of studies suggest that uncontrolled release of pro- and anti-inflammatory mediators by neurons, glial, and immune cells is also important in the emergence and maintenance of SCI-induced chronic pain. This constitutes the topic of the present mini-review, which will focus on the importance of neuro-immune dysregulation for pain after SCI.

Dysregulation in the expression of (lncRNA-TSIX, TP53INP2 mRNA, miRNA-1283) in spinal cord injury

AIM

The objective of this study is to examine the alterations in the levels of expression of serum lncRNA-TSIX, TP53INP2 mRNA, miRNA-1283 in spinal cord injured (SCI) patients versus healthy control.

METHOD

The expression of the selected RNAs in the sera was determined in 23 patients suffering from acute spinal cord injury, 41 individuals with chronic spinal cord injury, and 36 healthy control using real-time reverse-transcription polymerase chain reaction method.

RESULTS

The results showed that lncRNA-TSIX and the TP53INP2 mRNA expression levels in SCI patients was overexpressed in comparison to the control group alongside with a significant downregulation of miR-1283. Statistically,there was a highly significant positive correlation between lnc-RNA-TRIX and TP53INP2 mRNA with inverse correlation between miRNA-1283 and lnc-RNA-TRIX based on fold changes.

CONCLUSION

Up-regulation of lncRNA-TSIX, TP53INP2 mRNA with downregulation of miRNA-1283 might be closely associated with progression of SCI.

Evaluation of a ketogenic diet for improvement of neurological recovery in individuals with acute spinal cord injury: study protocol for a randomized controlled trial

BACKGROUND

Therapies that significantly improve the neurological and functional recovery of individuals with spinal cord injury (SCI) are still urgently needed. The ketogenic diet (KD) has been shown to improve forelimb motor function in an SCI rat model, likely by reducing inflammation and cell death in the spinal cord. Furthermore, our recent pilot study in patients with SCI showed that, compared with a standard hospital diet (SD), 5 weeks of KD started during acute care improved upper extremity motor function and reduced serum levels of a neuroinflammatory blood protein. The primary goals of the current study are to: 1) show the safety and feasibility of administering a KD during acute care for SCI; 2) determine if consuming 5 weeks of a KD significantly improves motor and sensory functions, functional independence and glycemic control; and 3) quantify serum biomarkers that are linked to improvements in neurological recovery and functional independence via targeted proteomics.

METHODS/DESIGN

In a single-masked, longitudinal, randomized, parallel-controlled study, a total of 60 eligible, acutely traumatic spinal cord injured (cervical 5 to thoracic 12) participants ranging in age from 18 to 60 years with American Spinal Injury Association impairment scale (AIS) grades A-C (AIS-A, sensorimotor complete; AIS-B, sensory incomplete/motor complete; and AIS-C, nonfunctional motor incomplete) are being enrolled. Neurological and functional examinations, resting energy expenditure, blood, urine, and stool collections, and protein analyses related to neurological recovery will be performed within 72 h of injury (baseline measure) and repeated after 5 weeks of KD or SD (discharge measure). We anticipate a completion rate of 80% with a total of 48 participants.

DISCUSSION

Intervention with a more neuroprotective diet during acute care of SCI can be implemented anywhere in the world at low cost and without major regulatory hurdles. Better functional recovery will lead to a better quality of life and long-term health outcomes in individuals with SCI. While this study targets SCI, if successful it has the potential to improve neurological outcomes for individuals with various traumatic injuries.

TRIAL REGISTRATION

NCT03509571 Registered on April 28, 2018.

Neuroprotective Agents as an Adjuvant Treatment in Patients With Acute Spinal Cord Injuries: A Qualitative Systematic Review of Randomized Trials

STUDY DESIGN

This was a systematic literature review.

OBJECTIVE

The objective of this study was to evaluate randomized clinical trials that address potential neuroprotective agents used to improve neurological outcome in patients with spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

Clinical treatment of acute SCI has evolved significantly, but neurological recovery of severely injured patients remains modest. Neuroprotective agents may act to limit secondary damage in the sequence of pathophysiologic insults that occur after primary SCI.

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines of all clinical randomized trials that evaluated potential neuroprotective agents (drugs, stem cells, and any type of medicative interventions) in neurological outcome of acute SCI. All the studies were graded according to their level of evidence in accordance with the Oxford Level of Evidence-based Medicine.

RESULTS

A total of 16 randomized clinical trials were included and fully analyzed in our review. The following 12 substances/drugs were analyzed: methylprednisolone (MP), naloxone, tirilizad, nimodipine, Sygen, autologous incubated macrophages, autologous bone marrow cells, minocycline, erythropoietin, ganglioside, vitamin D, and progesterone. Modest benefits were attributed to minocycline and Sygen (without statistical significance), and some benefits were obtained with erythropoietin and progesterone plus vitamin D in neurological outcome. For MP, the benefits are also controversial and may be attributed to statistical artifacts and with a high risk of adverse effects. The other substances did not change the final outcome. All studies were considered as grade B of recommendation (100%) and levels of evidences as B2 (81.25%) and B3 (18.75%).

CONCLUSIONS

Our review reported some potential substances that may improve neurological outcome in acute SCI: MP, vitamin D associated with progesterone, and erythropoietin. Their potential benefits were modest in the evaluated studies, requiring further randomized clinical trials with large samples of patients, without statistical artifacts, for routine clinical use. Furthermore, potential adverse effects must be considered with the use of neuroprotective agents in SCI. Until then, the use of these substances may be experimental or restricted to specific clinical situations.

Therapeutic repair for spinal cord injury: combinatory approaches to address a multifaceted problem

The recent years saw the advent of promising preclinical strategies that combat the devastating effects of a spinal cord injury (SCI) that are progressing towards clinical trials. However, individually, these treatments produce only modest levels of recovery in animal models of SCI that could hamper their implementation into therapeutic strategies in spinal cord injured humans. Combinational strategies have demonstrated greater beneficial outcomes than their individual components alone by addressing multiple aspects of SCI pathology. Clinical trial designs in the future will eventually also need to align with this notion. The scenario will become increasingly complex as this happens and conversations between basic researchers and clinicians are required to ensure accurate study designs and functional readouts.

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.

Possible Strategies to Optimize a Biomarker Discovery Approach to Correlate with Neurological Outcome in Patients with Spinal Cord Injury: A Pilot Study

The lack of reliable diagnostic and prognostic markers for spinal cord injured (SCI) patients is a severe obstacle in development and testing of new therapies, and it also impairs appropriate rehabilitation care. The sparse available data on the biochemical composition of cerebrospinal fluid (CSF) during the acute and/or chronic phase of the lesion provide, up until now, inconsistent results. In this pilot study, we then explored the possibility of combining a multi-parametric and bioinformatic analysis of CSF for its biological properties tested on different cells types, suitable for investigating inflammation and re-myelination. The patient enrollment was based on stringent inclusion criteria; that is, cervical and thoracic SCI trauma, CSF collection within 24 h of trauma, type of surgical approach for spine stabilization, and absence of steroid therapy before CSF collection. Eleven SCI patients and four healthy controls were included, and in three patients, CSF was also collected at 3 months after lesion. We identified 19 proteins among the 60 investigated cytokines, chemokines, growth factors, and structural biomarkers, which are transiently regulated 24 h after SCI. A bioinformatic analysis indicated that interleukin (IL)-6 and IL-10 are in the core of the interconnected net of activated proteins. Cell-based experiments indicate that CSF from SCI patients stimulates astroglia derivation from neural precursor cells, and an inverse correlation between IL-8 CSF level and oligodendrocyte precursor cells generated from neural stem cells was also observed. Results from this pilot study suggest that using a combined bioanalytic and biological approach to analyze SCI CSF at different times after injury could be a useful approach for identifying reliable diagnostic and prognostic markers in SCI.

MicroRNA Biomarkers in Cerebrospinal Fluid and Serum Reflect Injury Severity in Human Acute Traumatic Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition with variability in injury mechanisms and neurologic recovery. Spinal cord impairment after SCI is measured and classified by a widely accepted standard neurological examination. In the very acute stages post-injury, however, this examination is extremely challenging (and often impossible) to conduct and has modest prognostic value in terms of neurological recovery. The lack of objective tools to classify injury severity and predict outcome is a barrier for clinical trials and thwarts development of therapies for those with SCI. Biological markers (biomarkers) represent a promising, complementary approach to these challenges because they represent an unbiased approach to classify injury severity and predict neurological outcome. Identification of a suitable panel of molecular biomarkers would comprise a fundamental shift in how patients with acute SCI are evaluated, stratified, and treated in clinical trials. MicroRNA are attractive biomarker candidates in neurological disorders for several reasons, including their stability in biological fluids, their conservation between humans and model mammals, and their tissue specificity. In this study, we used next-generation sequencing to identify microRNA associated with injury severity within the cerebrospinal fluid (CSF) and serum of human patients with acute SCI. The CSF and serum samples were obtained 1-5 days post-injury from 39 patients with acute SCI (24 American Spinal Injury Association Impairment Scale [AIS] A, 8 AIS B, 7 AIS C) and from five non-SCI controls. We identified a severity-dependent pattern of change in microRNA expression in CSF and identified a set of microRNA that are diagnostic of baseline AIS classification and prognostic of neurological outcome six months post-injury. The data presented here provide a comprehensive description of the CSF and serum microRNA expression changes that occur after acute human SCI. This data set reveals microRNA candidates that warrant further evaluation as biomarkers of injury severity after SCI and as key regulators in other neurological disorders.

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.

Protein Profiling in Serum and Cerebrospinal Fluid Following Complex Surgery on the Thoracic Aorta Identifies Biological Markers of Neurologic Injury

Surgery on the arch or descending aorta is associated with significant risk of neurological complications. As a consequence of intubation and sedation, early neurologic injury may remain unnoticed. Biomarkers to aid in the initial diagnostics could prove of great value as immediate intervention is critical. Twenty-three patients operated in the thoracic aorta with significant risk of perioperative neurological injury were included. Cerebrospinal fluid (CSF) and serum were obtained preoperatively and in the first and second postoperative days and assessed with a panel of 92 neurological-related proteins. Three patients suffered spinal cord injury (SCI), eight delirium, and nine hallucinations. There were markers in both serum and CSF that differed between the affected and non-affected patients (SCI; IL6, GFAP, CSPG4, delirium; TR4, EZH2, hallucinations; NF1). The study identifies markers in serum and CSF that reflect the occurrence of neurologic insults following aortic surgery, which may aid in the care of these patients.