Expansion duroplasty improves intraspinal pressure, spinal cord perfusion pressure, and vascular pressure reactivity index in patients with traumatic spinal cord injury: injured spinal cord pressure evaluation study

Invasive devices to monitor the intraspinal perfusion pressure in the hemodynamic management of acute spinal cord injury: A systematic scoping review

BACKGROUND

Various methods for measuring intrathecal pressure (ITP) after spinal cord injury (SCI) to guide hemodynamic management have been investigated. To synthesize the current literature, this current study conducted a scoping review of the use of intrathecal devices to monitor ITP during acute management of SCI with the aim of understanding the association between ITP monitoring with physiological and clinical outcomes.

METHODS

A systematic review of literature following the Cochrane Handbook for Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. All eligible studies were screened for inclusion and exclusion criteria. Data extracted included number of patients included, severity of injury, characteristics of the intervention-intrathecal device used to record the ITP, outcomes -hemodynamic parameters observed, changes in the American Spinal Injury Association (ASIA) Impairment Scale (AIS), total motor scores, association of ITP with other physiological variables.

RESULTS

The search yielded a total of 1,698 articles, of which 30 observational studies and 2 randomized clinical trials were deemed eligible based on their use of an intrathecal invasive device to monitor spinal cord perfusion pressure (SCPP) in patients with SCI. Of these, 9 studies used a lumbar drain, 23 a Codman pressure probe and 1 study that used both. These studies underscore the crucial interplay between ITP, the SCPP and physiological variables, with neurological outcome. It is still unclear whether monitoring from a lumbar drain is accurate enough to highlight what is occurring at the site of SCI, which is the main advantage of Codman Probe, however, the latter requires specialized personnel that may not be available in most settings. Minor adverse effects were associated with lumbar drain catheters, while cerebrospinal fluid leak requiring repair (~ 7%) is the main concern with Codman Probes.

CONCLUSION

Future investigation of SCPP protocols via lumbar drains and Codman probes ought to involve multi-centered randomized controlled trials and continued translational investigation with animal models.

Cerebrospinal fluid pressure dynamics across the intra- and postoperative setting: Retrospective study of a spine surgery cohort

Timely and sufficient decompression are critical objectives in degenerative cervical myelopathy (DCM) and spinal cord injury (SCI). We previously investigated intraoperative cerebrospinal fluid pressure (CSFP) for determining surgical outcomes. However, confounding factors during the intra- and postoperative setting need consideration. These are related to type of respiration (i.e., artificial vs. natural) and anesthesia, which affect CSFP dynamics through the interaction between the cardiorespiratory system and the CSF compartment. This retrospective cohort study (NCT02170155) aims to systematically investigate these factors to facilitate CSFP interpretation. CSFP was continuously measured through a lumbar catheter, intra- and postoperatively, in 21 patients with DCM undergoing decompression surgery. Mean CSFP and cardiac-driven CSFP peak-to-valley amplitude (CSFPp) were analyzed throughout the perioperative period, including the immediate extubation period in eight patients. Intraoperative mean CSFP had a median value and {interquartile range} of 10.8 {5.5} mmHg and increased 1.6-fold to 16.9 {7.1} mmHg postoperatively (p < 0.001). CSFPp increased 3-fold from 0.6 {0.7} to 1.8 {2.5} mmHg (p = 0.001). Increased CSFP persisted overnight. During extubation, there was a notable increase in CSFP and CSFPp of 14.0 {5.8} and 5.1 {3.1} mmHg, respectively. From case-based analysis, this was attributed to an arterial pCO2 increase. There was no correlation between respirator settings and CSFP metrics. There were distinct and quantifiable changes in CSFP dynamics from the intra- to postoperative setting related to type of respiration, anesthesia, and level of consciousness. When monitoring CSFP dynamics in spine surgery across these settings, cardiorespiratory factors must be controlled for.

Nerve Bypass Surgery for Spinal Cord Reconstruction

OBJECTIVE

Spinal cord injury (SCI) is a devastating condition that significantly decreases the patient's quality of life. Therefore, treatments that can facilitate nerve regeneration, reduce complications, and increase quality of life are valuable for these patients. In this study, we aimed to assess nerve bypass surgery's feasibility and clinical outcomes by transferring the intercostal nerves into the spinal cord.

METHODS

Eight patients with complete thoracic SCI and delayed presentation more than a year after the injury were analyzed retrospectively. All patients underwent nerve bypass surgery with the transfer of 2 pairs of intercostal nerves from proximal to the injury site to the anterolateral spinal cord, followed by duraplasty with fascia grafting to close the dura.

RESULTS

Six of the 8 (75%) patients demonstrated motor and sensory improvements, based on the American SCI Association score. Three patients demonstrated a limited recovery of motor function that could be independently triggered without ICN initiation. Five patients demonstrated evidence of cerebrospinal fluid leakage after surgery; however, only 1 patient complained of a headache.

CONCLUSIONS

Spinal cord bypass surgery is a potential reconstruction method to treat chronic complete thoracic SCI with functional improvements, and is worth further investigation.

Thoracolumbar spinal cord injury: management, techniques, timing

Acute traumatic spinal cord injury (tSCI) is a complex and heterogeneous injury, where the level of injury, injury severity, duration and degree of spinal cord compression, and blood pressure management seem to influence neurologic outcome. Although data in the literature seem to be inconsistent regarding the effectiveness of surgical decompression and spinal fixation in patients with thoracic and thoracolumbar tSCI, some single-center studies suggest that early surgical decompression may lead to a superior neurologic outcome, especially in patients with incomplete tSCI, suggesting surgical decompression to be performed as soon as possible. However, high energy injuries, especially to the upper thoracic levels, may be too severe to be influenced by surgical decompression, which may represent a critical second hit for the polytraumatized patient. Therefore, the surgeon first needs to critically evaluate the potential for neurologic recovery in each patient before determining the ideal timing of surgery. Circulatory stabilization must be achieved before surgical intervention, and minimally invasive procedures should be preferred. Invasive blood pressure monitoring should be started on admission, and maintenance of a MAP between 85 and 90 mmHg is recommended for a duration of 5-7 days, with special attention to the prevention of hypoxia, fever, acidosis and deep venous thrombosis. The role of a 24-hour infusion of high-dose MPSS is still controversial, but it may be offered at the discretion of the treating surgeon to adult patients within 8 h of acute tSCI as a treatment option, especially in the case of very early decompression or incomplete tSCI.

Advanced neuromonitoring powered by ICM+ and its place in the Brand New AI World, reflections at the 20th anniversary boundary

Introduction

Adoption of the ICM+® brain monitoring software by clinical research centres worldwide has been continuously growing over the past 20 years. This has necessitated ongoing updates to accommodate evolving neuromonitoring research needs, including recent explosion of artificial intelligence (AI).

Research question

We sought to provide an update on the current features of the software. In particular, we aimed to highlight the new options of integrating AI models.

Material and methods

We reviewed all currently available ICM+ analytical areas and discussed potential AI based extensions in each. We tested a proof-of-concept integration of an AI model and evaluated its performance for real-time data processing.

Results

ICM+ current analytical tools serve both real-time (bed-side) and offline (file based) analysis, including the calculation engine, Signal Calculator, Custom Statistics, Batch tools, ScriptLab and charting. The ICM+ Python plugin engine allows to execute custom Python scripts and take advantage of complex AI frameworks. For the proof-of-concept, we used a neural network convolutional model with 207,000 trainable parameters that classifies morphology of intracranial pressure (ICP) pulse waveform into 5 pulse categories (normal to pathological plus artefactual). When evaluated within ICM+ plugin script on a Windows 10 laptop the classification of a 5 min ICP waveform segment took only 0.19s with a 2.3s of initial, one-off, model loading time required.

Conclusions

Modernised ICM+ analytical tools, reviewed in this manuscript, include integration of custom AI models allowing them to be shared and run in real-time, facilitating rapid prototyping and validating of new AI ideas at the bed-side.

Advancements in neuroregenerative and neuroprotective therapies for traumatic spinal cord injury

Traumatic spinal cord injuries (SCIs) continue to be a major healthcare concern, with a rising prevalence worldwide. In response to this growing medical challenge, considerable scientific attention has been devoted to developing neuroprotective and neuroregenerative strategies aimed at improving the prognosis and quality of life for individuals with SCIs. This comprehensive review aims to provide an up-to-date and thorough overview of the latest neuroregenerative and neuroprotective therapies currently under investigation. These strategies encompass a multifaceted approach that include neuropharmacological interventions, cell-based therapies, and other promising strategies such as biomaterial scaffolds and neuro-modulation therapies. In addition, the review discusses the importance of acute clinical management, including the role of hemodynamic management as well as timing and technical aspects of surgery as key factors mitigating the secondary injury following SCI. In conclusion, this review underscores the ongoing scientific efforts to enhance patient outcomes and quality of life, focusing on upcoming strategies for the management of traumatic SCI. Each section provides a working knowledge of the fundamental preclinical and patient trials relevant to clinicians while underscoring the pathophysiologic rationale for the therapies.

Under pressure - A historical vignette on surgical timing in traumatic spinal cord injury

Introduction

It was not even a century ago when a spinal cord injury (SCI) would inevitably result in a fatal outcome, particularly for those with complete SCI. Throughout history, there have been extensive endeavours to change the prospects for SCI patients by performing surgery, even though many believed that there was no way to alter the catastrophic course of SCI. To this day, the debate regarding the efficacy of surgery in improving the neurological outcome for SCI patients persists, along with discussions about the timing of surgical intervention.

Research question

How have the historical surgical results shaped our perspective on the surgical treatment of SCI?

Material and methods

Narrative literature review.

Results

Throughout history there have been multiple surgical attempts to alter the course of SCI, with conflicting results. While studies suggest a potential link between timing of surgery and neurological recovery, the exact impact of immediate surgery on individual cases remains ambiguous. It is becoming more evident that, alongside surgical intervention, factors specific to both the patient and their surgical treatment will significantly influence neurological recovery.

Conclusion

Although a growing number of studies indicates a potential correlation of surgical timing and neurological outcome, the precise influence of urgent surgery on an individual basis remains uncertain. It is increasingly apparent that, despite surgery, patient- and treatment-specific factors will also play a role in determining the neurological outcome. Notably, these very factors have influenced the results in previous studies and our views concerning surgical timing.

A 72-h sedated porcine model of traumatic spinal cord injury

Introduction

There is an increasing focus on the prevention of secondary injuries following traumatic spinal cord injury (TSCI), especially through improvement of spinal cord perfusion and immunological modulation. Such therapeutic strategies require translational and controlled animal models of disease progression of the acute phases of human TSCI.

Research question

Is it possible to establish a 72-h sedated porcine model of incomplete thoracic TSCI, enabling controlled use of continuous, invasive, and non-invasive modalities during the entire sub-acute phase of TSCI?

Material and methods

A sham-controlled trial was conducted to establish the model, and 10 animals were assigned to either sham or TSCI. All animals underwent a laminectomy, and animals in the TSCI group were subjected to a weight-drop injury. Animals were then kept sedated for 72 h. The amount of injury was assessed by ex-vivo measures MRI-based fiber tractography, histology and immunohistochemistry.

Results

In all animals, we were successful in maintaining sedation for 72 h without comprising vital physiological parameters. The MRI-based fiber tractography showed that all TSCI animals revealed a break in the integrity of spinal neurons, whereas histology demonstrated no transversal sections of the spine with complete injury. Notably, some animals displayed signs of secondary ischemic tissue in the cranial and caudal sections.

Discussion and conclusions

This study succeeded in producing a porcine model of incomplete TSCI, which was physiologically stable up to 72 h. We believe that this TSCI model will constitute a potential translational model to study the pathophysiology secondary to TSCI in humans.

Neurocritical care and neuromonitoring considerations in acute pediatric spinal cord injury

Management of pediatric spinal cord injury (SCI) is an essential skill for all pediatric neurocritical care physicians. In this review, we focus on the evaluation and management of pediatric SCI, highlight a novel framework for the monitoring of such patients in the intensive care unit (ICU), and introduce advancements in critical care techniques in monitoring and management. The initial evaluation and characterization of SCI is crucial for improving outcomes as well as prognostication. While physical examination and imaging are the main stays of the work-up, we propose the use of somatosensory evoked potentials (SSEPs) and transcranial magnetic stimulation (TMS) for challenging clinical scenarios. SSEPs allow for functional evaluation of the dorsal columns consisting of tracts associated with hand function, ambulation, and bladder function. Meanwhile, TMS has the potential for informing prognostication as well as response to rehabilitation. Spine stabilization, and in some cases surgical decompression, along with respiratory and hemodynamic management are essential. Emerging research suggests that targeted spinal cerebral perfusion pressure may provide potential benefits. This review aims to increase the pediatric neurocritical care physician's comfort with SCI while providing a novel algorithm for monitoring spinal cord function in the ICU.

Spinal Cord Injury: Emerging Technologies

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

Spinal decompression surgery may alleviate vasopressor-induced spinal hemorrhage and extravasation during acute cervical spinal cord injury in rats

BACKGROUND

Cervical spinal injury often disrupts the supraspinal vasomotor pathways projecting to the thoracic sympathetic preganglionic neurons, leading to cardiovascular dysfunction. The current guideline is to maintain the mean arterial blood pressure at 85 to 90 mmHg using a vasopressor during the first week of the injury. Some studies have demonstrated that this treatment might be beneficial to alleviate secondary injury and improve neurological outcomes; however, elevation of blood pressure may exacerbate spinal hemorrhage, extravasation, and edema, exacerbating the initial injury.

PURPOSE

The present study was designed to (1) examine whether vasopressor administration exacerbates spinal hemorrhage and extravasation; (2) evaluate whether spinal decompression surgery relieves vasopressor-induced spinal hemorrhage and extravasation.

STUDY DESIGN

In vivo animal study.

METHODS

Animals received a saline solution or a vasopressor (phenylephrine hydrochloride, 500 or 1000 μg/kg, 7 mL/kg/h) after mid-cervical contusion with or without spinal decompression (ie, incision of the dura and arachnoid mater). Spinal cord hemorrhage and extravasation were examined by expression of Evans blue within the spinal cord section.

RESULTS

The results demonstrated that cervical spinal contusion significantly reduced the mean arterial blood pressure and induced spinal hemorrhage and extravasation. Phenylephrine infusion significantly elevated the mean arterial blood pressure to the preinjury level within 15 to 60 minutes postcontusion; however, spinal hemorrhage and extravasation were more extensive in animals that received phenylephrine than in those that received saline. Notably, spinal decompression mitigated spinal hemorrhage and extravasation in contused rats who received phenylephrine.

CONCLUSIONS

These data indicate that, although phenylephrine can prevent hypotension after cervical spinal injury, it also causes excess spinal hemorrhage and extravasation.

CLINICAL SIGNIFICANCE

Spinal decompressive surgery seemed to minimize the side effect of phenylephrine as vasopressor treatment during acute spinal cord injury.

A Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on Hemodynamic Management

STUDY DESIGN

Clinical practice guideline development following the GRADE process.

OBJECTIVES

Hemodynamic management is one of the only available treatment options that likely improves neurologic outcomes in patients with acute traumatic spinal cord injury (SCI). Augmenting mean arterial pressure (MAP) aims to improve blood perfusion and oxygen delivery to the injured spinal cord in order to minimize secondary ischemic damage to neural tissue. The objective of this guideline was to update the 2013 AANS/CNS recommendations on the hemodynamic management of patients with acute traumatic SCI, acknowledging that much has been published in this area since its publication. Specifically, we sought to make recommendations on 1. The range of mean arterial pressure (MAP) to be maintained by identifying an upper and lower MAP limit; 2. The duration of such MAP augmentation; and 3. The choice of vasopressor. Additionally, we sought to make a recommendation on spinal cord perfusion pressure (SCPP) targets.

METHODS

A multidisciplinary guideline development group (GDG) was formed that included health care professionals from a wide range of clinical specialities, patient advocates, and individuals living with SCI. The GDG reviewed the 2013 AANS/CNS guidelines and voted on whether each recommendation should be endorsed or updated. A systematic review of the literature, following PRISMA standards and registered in PROSPERO, was conducted to inform the guideline development process and address the following key questions: (i) what are the effects of goal-directed interventions to optimize spinal cord perfusion on extent of neurological recovery and rates of adverse events at any time point of follow-up? and (ii) what are the effects of particular monitoring techniques, perfusion ranges, pharmacological agents, and durations of treatment on extent of neurological recovery and rates of adverse events at any time point of follow-up? The GDG combined the information from this systematic review with their clinical expertise in order to develop recommendations on a MAP target range (specifically an upper and lower limit to target), the optimal duration for MAP augmentation, and the use of vasopressors or inotropes. Using methods outlined by the GRADE working group, recommendations were formulated that considered the balance of benefits and harms, financial impact, acceptability, feasibility and patient preferences.

RESULTS

The GDG suggested that MAP should be augmented to at least 75-80 mmHg as the "lower limit," but not actively augmented beyond an "upper limit" of 90-95 mmHg in order to optimize spinal cord perfusion in acute traumatic SCI. The quality of the evidence around the "target MAP" was very low, and thus the strength of this recommendation is weak. For duration of hemodynamic management, the GDG "suggested" that MAP be augmented for a duration of 3-7 days. Again, the quality of the evidence around the duration of MAP support was very low, and thus the strength of this recommendation is also weak. The GDG felt that a recommendation on the choice of vasopressor or the use of SCPP targets was not warranted, given the dearth of available evidence.

CONCLUSION

We provide new recommendations for blood pressure management after acute SCI that acknowledge the limitations of the current evidence on the relationship between MAP and neurologic recovery. It was felt that the low quality of existing evidence and uncertainty around the relationship between MAP and neurologic recovery justified a greater range of MAP to target, and for a broader range of days post-injury than recommended in previous guidelines. While important knowledge gaps still remain regarding hemodynamic management, these recommendations represent current perspectives on the role of MAP augmentation for acute SCI.

Randomized Controlled Trial of Durotomy as an Adjunct to Routine Decompressive Surgery for Dogs With Severe Acute Spinal Cord Injury

Although many interventions for acute spinal cord injury (SCI) appear promising in experimental models, translation directly from experimental animals to human patients is a large step that can be problematic. Acute SCI occurs frequently in companion dogs and may provide a model to ease translation. Recently, incision of the dura has been highlighted in both research animals and human patients as a means of reducing intraspinal pressure, with a view to improving perfusion of the injured tissue and enhancing functional recovery. Observational clinical data in humans and dogs support the notion that it may also improve functional outcome. Here, we report the results of a multi-center randomized controlled trial of durotomy as an adjunct to traditional decompressive surgery for treatment of severe thoracolumbar SCI caused by acute intervertebral disc herniation in dogs. Sample-size calculation was based on the proportion of dogs recovering ambulation improving from an expected 55% in the traditional surgery group to 70% in the durotomy group. Over a 3.5-year period, we enrolled 140 dogs, of which 128 had appropriate duration of follow-up. Overall, 65 (51%) dogs recovered ambulation. Recovery in the traditional decompression group was 35 of 62 (56%) dogs, and in the durotomy group 30 of 66 (45%) dogs, associated with an odds ratio of 0.643 (95% confidence interval: 0.320-1.292) and z-score of -1.24. This z-score indicates trial futility to reach the target 15% improvement over traditional surgery, and the trial was terminated at this stage. We conclude that durotomy is ineffective in improving functional outcome for severe acute thoracolumbar SCI in dogs. In the future, these data can be compared with similar data from clinical trials on duraplasty in human patients and will aid in determining the predictive validity of the "companion dog model" of acute 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.

A Review of Strategies Associated with Surgical Decompression in Traumatic Spinal Cord Injury

Traumatic spinal cord injury (TSCI) is frequent. Timely diagnosis and treatment have reduced the mortality, but the long-term recovery of neurologic functions remains ominous. After TSCI, tissue bleeding, edema, and adhesions lead to an increase in the intraspinal pressure, further causing the pathophysiologic processes of ischemia and hypoxia and eventually accelerating the cascade of secondary spinal cord injury. Timely surgery with appropriate decompression strategies can reduce that secondary injury. However, disagreement about the safety and effectiveness of decompression surgery and the timing of surgery still exists. The level and severity of spinal cord injury do have an impact on the timing of surgery; therefore, TSCI subpopulations may benefit from early surgery. Early surgery perhaps has little effect on recovery from complete TSCI but might be of benefit in patients with incomplete injury. Early decompression should be considered in patients with incomplete cervical TSCI. Patient age should not be used as an exclusion criterion for early surgery. The best time point for early surgery is although influenced by the shortest duration to thoroughly examine the patient's condition and stabilize the patient's state. After the patient's condition is fully evaluated, we can perform the surgical modality of emergency myelotomy and decompression. Therefore, a number of conditions should be considered, such as standardized decompression methods, indications and operation timing to ensure the effectiveness and safety of early surgical intervention, and promotion of the functional recovery of residual nerve tissue.

Posterior spinal decompression in adults with spinal cord injury without traumatic compromise of the spinal canal: what is the data?

Background

Spinal cord injury (SCI) can be caused by a variety of factors and its severity can range from a mild concussion to a complete severing of the spinal cord. Τreatment depends on the type and severity of injury, the patient's age and overall health. Reduction of dislocated or fractured vertebrae via closed manipulation or surgical procedures, fixation and removal of bony fragments and debris that compromise the spinal canal are indicated for decompression of the spinal cord and stabilization of the spine. However, when there is no obvious traumatic obstruction of spinal canal, the question arises as to whether laminectomy is needed to be performed to improve neurological outcome.

Methods

A literature review covering all indexed studies published between 2013 and 2023 was performed using keywords to identify the patient group of interest (spinal cord injury, SCI, spinal cord trauma, cervical, thoracic, lumbar, thoracolumbar),central cord syndrome (CCS) and the interventions (laminectomy, laminoplasty, decompression, duroplasty).

Results

This review includes6 observational studies investigating the outcome of posterior spinal decompression in patients suffering from spinal cord injury without traumatic spinal cord stenosis. Most patients already had degenerative stenosis. From a total of 202, 151 patients (74.7%) improved neurologically by at least one grade at ASIA scale, after being treated with either laminectomy, laminoplasty, duroplasty or a combination of these techniques.

Conclusion

Early decompression in SCI patients remains a reasonable practice option and can be performed safely, but no specific evidence supports the use of laminectomy alone. There is emerging evidence that intended durotomy followed by extended meningoplasty may improve the neurological outcome in patients suffering from SCI when meta-traumatic edema is apparent. However, the lack of high-quality evidence and results support the need for further research.

Early surgical intervention for acute spinal cord injury: time is spine

Acute traumatic spinal cord injury (tSCI) is a devastating occurrence that significantly contributes to global morbidity and mortality. Surgical decompression with stabilization is the most effective way to minimize the damaging sequelae that follow acute tSCI. In recent years, strong evidence has emerged that supports the rationale that early surgical intervention, within 24 h following the initial injury, is associated with a better prognosis and functional outcomes. In this review, we have summarized the evidence and elaborated on the nuances of this concept. Additionally, we have reviewed further concepts that stem from "time is spine," including earlier cutoffs less than 24 h and the challenging entity of central cord syndrome, as well as the emerging concept of adequate surgical decompression. Lastly, we identify barriers to early surgical care for acute tSCI, a key aspect of spine care that needs to be globally addressed via research and policy on an urgent basis.

Updates in the Early Management of Acute Spinal Cord Injury

Spinal cord injury (SCI) is a leading cause of disability worldwide, and effective management is necessary to improve clinical outcomes. Many long-standing therapies including early reduction and spinal cord decompression, methylprednisolone administration, and optimization of spinal cord perfusion have been around for decades; however, their efficacy has remained controversial because of limited high-quality data. This review article highlights studies surrounding the role of early surgical decompression and its role in relieving mechanical pressure on the microvascular circulation thereby reducing intraspinal pressure. Furthermore, the article touches on the current role of methylprednisolone and identifies promising studies evaluating neuroprotective and neuroregenerative agents. Finally, this article outlines the expanding body of literature evaluating mean arterial pressure goals, cerebrospinal fluid drainage, and expansive duroplasty to further optimize vascularization to the spinal cord. Overall, this review aims to highlight evidence for SCI treatments and ongoing trials that may markedly affect SCI care in the near future.

Duroplasty for injured cervical spinal cord with uncontrolled swelling: protocol of the DISCUS randomized controlled trial

BACKGROUND

Cervical traumatic spinal cord injury is a devastating condition. Current management (bony decompression) may be inadequate as after acute severe TSCI, the swollen spinal cord may become compressed against the surrounding tough membrane, the dura. DISCUS will test the hypothesis that, after acute, severe traumatic cervical spinal cord injury, the addition of dural decompression to bony decompression improves muscle strength in the limbs at 6 months, compared with bony decompression alone.

METHODS

This is a prospective, phase III, multicenter, randomized controlled superiority trial. We aim to recruit 222 adults with acute, severe, traumatic cervical spinal cord injury with an American Spinal Injury Association Impairment Scale grade A, B, or C who will be randomized 1:1 to undergo bony decompression alone or bony decompression with duroplasty. Patients and outcome assessors are blinded to study arm. The primary outcome is change in the motor score at 6 months vs. admission; secondary outcomes assess function (grasp, walking, urinary + anal sphincters), quality of life, complications, need for further surgery, and mortality, at 6 months and 12 months from randomization. A subgroup of at least 50 patients (25/arm) also has observational monitoring from the injury site using a pressure probe (intraspinal pressure, spinal cord perfusion pressure) and/or microdialysis catheter (cord metabolism: tissue glucose, lactate, pyruvate, lactate to pyruvate ratio, glutamate, glycerol; cord inflammation: tissue chemokines/cytokines). Patients are recruited from the UK and internationally, with UK recruitment supported by an integrated QuinteT recruitment intervention to optimize recruitment and informed consent processes. Estimated study duration is 72 months (6 months set-up, 48 months recruitment, 12 months to complete follow-up, 6 months data analysis and reporting results).

DISCUSSION

We anticipate that the addition of duroplasty to standard of care will improve muscle strength; this has benefits for patients and carers, as well as substantial gains for health services and society including economic implications. If the addition of duroplasty to standard treatment is beneficial, it is anticipated that duroplasty will become standard of care.

TRIAL REGISTRATION

IRAS: 292031 (England, Wales, Northern Ireland) - Registration date: 24 May 2021, 296518 (Scotland), ISRCTN: 25573423 (Registration date: 2 June 2021); ClinicalTrials.gov number : NCT04936620 (Registration date: 21 June 2021); NIHR CRN 48627 (Registration date: 24 May 2021).

Spinal cord injury: molecular mechanisms and therapeutic interventions

Spinal cord injury (SCI) remains a severe condition with an extremely high disability rate. The challenges of SCI repair include its complex pathological mechanisms and the difficulties of neural regeneration in the central nervous system. In the past few decades, researchers have attempted to completely elucidate the pathological mechanism of SCI and identify effective strategies to promote axon regeneration and neural circuit remodeling, but the results have not been ideal. Recently, new pathological mechanisms of SCI, especially the interactions between immune and neural cell responses, have been revealed by single-cell sequencing and spatial transcriptome analysis. With the development of bioactive materials and stem cells, more attention has been focused on forming intermediate neural networks to promote neural regeneration and neural circuit reconstruction than on promoting axonal regeneration in the corticospinal tract. Furthermore, technologies to control physical parameters such as electricity, magnetism and ultrasound have been constantly innovated and applied in neural cell fate regulation. Among these advanced novel strategies and technologies, stem cell therapy, biomaterial transplantation, and electromagnetic stimulation have entered into the stage of clinical trials, and some of them have already been applied in clinical treatment. In this review, we outline the overall epidemiology and pathophysiology of SCI, expound on the latest research progress related to neural regeneration and circuit reconstruction in detail, and propose future directions for SCI repair and clinical applications.

Subacute Posttraumatic Ascending Myelopathy: Case Report and Systematic Review of the Literature

STUDY DESIGN

Case report and literature review.

OBJECTION

Aim of this study was to summarize the current evidence base behind subacute posttraumatic ascending myelopathy (SPAM) including the epidemiology, presentation, diagnosis, prognosis, and etiology.

SUMMARY OF BACKGROUND DATA

SPAM is a rare, potentially fatal disorder which is not attributable to ongoing mechanical instability, syrinx formation, or iatrogenic causes.

METHODS

A systematic literature search on SPAM was performed on Medline, Ovid, Cochrane, Embase, and PubMed databases between 1969 and 2021. Cases were reviewed and the findings summarized. Further evidence was reviewed to support the hypothesis that disruption of cerebrospinal fluid (CSF) circulation is the underlying etiology of the condition.

RESULTS

It is estimated to occur in 0.4%-0.7% of spinal cord injuries and may have a mortality of up to 10%. The most likely etiology disruption of CSF circulation leading to further damage to the spinal cord presumably through pressure mediated effects such as a reduction in cellular perfusion.

CONCLUSION

There is effectively no treatment of this condition, however, with interest developing in monitoring of CSF pressures during spinal cord injury this may help confirm the etiology, and allow the suggestion of therapies such as drains or expansion duraplasty to reduce spinal cord pressures.

LEVEL OF EVIDENCE

Level II-case report and systematic review.

Cerebrospinal Fluid Pressure Dynamics as a Bedside Test in Traumatic Spinal Cord Injury to Assess Surgical Spinal Cord Decompression: Safety, Feasibility, and Proof-of-Concept

BACKGROUND

Sufficient and timely spinal cord decompression is a critical surgical objective for neurological recovery in spinal cord injury (SCI). Residual cord compression may be associated with disturbed cerebrospinal fluid pressure (CSFP) dynamics.

OBJECTIVES

This study aims to assess whether intrathecal CSFP dynamics in SCI following surgical decompression are feasible and safe, and to explore the diagnostic utility.

METHODS

Prospective cohort study. Bedside lumbar CSFP dynamics and cervical MRI were obtained following surgical decompression in N = 9 with mostly cervical acute-subacute SCI and N = 2 patients with non-traumatic SCI. CSFP measurements included mean CSFP, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp), Valsalva maneuver, and Queckenstedt's test (firm pressure on jugular veins, QT). From QT, proxies for cerebrospinal fluid pulsatility curve were calculated (ie, relative pulse pressure coefficient; RPPC-Q). CSFP metrics were compared to spine-healthy patients. computer tomography (CT)-myelography was done in 3/8 simultaneous to CSFP measurements.

RESULTS

Mean age was 45 ± 9 years (range 17-67; 3F), SCI was complete (AIS A, N = 5) or incomplete (AIS B-D, N = 6). No adverse events related to CSFP assessments. CSFP rise during QT was induced in all patients [range 9.6-26.6 mmHg]. However, CSFPp was reduced in 3/11 (0.1-0.3 mmHg), and in 3/11 RPPC-Q was abnormal (0.01-0.05). Valsalva response was reduced in 8/11 (2.6-23.4 mmHg). CSFP dynamics corresponded to CT-myelography.

CONCLUSIONS

Comprehensive bedside lumbar CSFP dynamics in SCI following decompression are safe, feasible, and can reveal distinct patterns of residual spinal cord compression. Longitudinal studies are required to define critical thresholds of impaired CSFP dynamics that may impact neurological recovery and requiring surgical revisions.

Predicting the Role of Preoperative Intramedullary Lesion Length and Early Decompressive Surgery in ASIA Impairment Scale Grade Improvement Following Subaxial Traumatic Cervical Spinal Cord Injury

BACKGROUND

 Traumatic cervical spinal cord injury (TCSCI) is a disabling condition with uncertain neurologic recovery. Clinical and preclinical studies have suggested early surgical decompression and other measures of neuroprotection improve neurologic outcome. We investigated the role of intramedullary lesion length (IMLL) on preoperative magnetic resonance imaging (MRI) and the effect of early cervical decompressive surgery on ASIA impairment scale (AIS) grade improvement following TCSCI.

METHODS

 In this retrospective study, we investigated 34 TCSCI patients who were admitted over a 12-year period, from January 1, 2008 to January 31, 2020. We studied the patient demographics, mode of injury, IMLL and timing of surgical decompression. The IMLL is defined as the total length of edema and contusion/hemorrhage within the cord. Short tau inversion recovery (STIR) sequences or T2-weighted MR imaging with fat saturation increases the clarity of edema and depicts abnormalities in the spinal cord. All patients included had confirmed adequate spinal cord decompression with cervical fixation and a follow-up of at least 6 months.

RESULTS

 Of the 34 patients, 16 patients were operated on within 24 hours (early surgery group) and 18 patients were operated on more than 24 hours after trauma (delayed surgery group). In the early surgery group, 13 (81.3%) patients had improvement of at least one AIS grade, whereas in the delayed surgery group, AIS grade improvement was seen in only in 8 (44.5%) patients (early vs. late surgery; odds ratio [OR] = 1.828; 95% confidence interval [CI]: 1.036-3.225). In multivariate regression analysis coefficients, the timing of surgery and intramedullary edema length on MRI were the most significant factors in improving the AIS grade following cervical SCI. Timing of surgery as a unique variance predicted AIS grade improvement significantly (p < 0.001). The mean IMLL was 41.47 mm (standard deviation [SD]: 18.35; range: 20-87 mm). IMLL was a predictor of AIS grade improvement on long-term outcome in bivariate analysis (p < 0.001). This study suggests that patients who had IMLL of less than 30 mm had a better chance of grade conversion irrespective of the timing of surgery. Patients with an IMLL of 31 to 60 mm had chances of better grade conversion after early surgery. A longer IMLL predicts lack of improvement (p < 0.05). If the IMLL is greater than 61 mm, the probability of nonconversion of AIS grade is higher, even if the patient is operated on within 24 hours of trauma.

CONCLUSION

 Surgical decompression within 24 hours of trauma and shorter preoperative IMLL are significantly associated with improved neurologic outcome, reflected by better AIS grade improvement at 6 months' follow-up. The IMLL on preoperative MRI can reliably predict outcome after 6 months. The present study suggests that patients have lesser chances of AIS grade improvement when the IMLL is ≥61 mm.

A decrease in the neuroprotective effects of acute spinal cord decompression according to injury severity: introducing the concept of a ceiling effect

OBJECTIVE

Acute traumatic spinal cord injury (tSCI) is followed by a prolonged period of secondary neuroglial cell death. Neuroprotective interventions, such as surgical spinal cord decompression, aim to mitigate secondary injury. In this study, the authors explore whether the effect size of posttraumatic neuroprotective spinal cord decompression varies with injury severity.

METHODS

Seventy-one adult female Long Evans rats were subjected to a thoracic tSCI using a third-generation spinal contusion device. Moderate and severe tSCI were defined by recorded impact force delivered to the spinal cord. Immediately after injury (< 15 minutes), treatment cohorts underwent either a decompressive durotomy or myelotomy. Functional recovery was documented using the Basso, Beattie, and Bresnahan locomotor scale, and tissue sparing was documented using histological analysis.

RESULTS

Moderate and severe injuries were separated at a cutoff point of 231.8 kdyn peak impact force based on locomotor recovery at 8 weeks after injury. Durotomy improved hindlimb locomotor recovery 8 weeks after moderate trauma (p < 0.01), but not after severe trauma (p > 0.05). Myelotomy led to increased tissue sparing (p < 0.0001) and a significantly higher number of spared motor neurons (p < 0.05) in moderate trauma, but no such effect was noted in severely injured rats (p > 0.05). Within the moderate injury group, myelotomy also resulted in significantly more spared tissue when compared with durotomy-only animals (p < 0.01).

CONCLUSIONS

These results suggest that the neuroprotective effects of surgical spinal cord decompression decrease with increasing injury severity in a rodent tSCI model.

Tensile properties of human spinal dura mater and pericranium

Autologous pericranium is a promising dural graft material. An optimal graft should exhibit similar mechanical properties to the native dura, but the mechanical properties of human pericranium have not been characterized, and studies of the biomechanical performance of human spinal dura are limited. The primary aim of this study was to measure the tensile structural and material properties of the pericranium, in the longitudinal and circumferential directions, and of the dura in each spinal region (cervical, thoracic and lumbar) and in three directions (longitudinal anterior and posterior, and circumferential). The secondary aim was to determine corresponding constitutive stress-strain equations using a one-term Ogden model. A total of 146 specimens were tested from 7 cadavers. Linear regression models assessed the effect of tissue type, region, and orientation on the structural and material properties. Pericranium was isotropic, while spinal dura was anisotropic with higher stiffness and strength in the longitudinal than the circumferential direction. Pericranium had lower strength and modulus than spinal dura across all regions in the longitudinal direction but was stronger and stiffer than dura in the circumferential direction. Spinal dura and pericranium had similar strain at peak force, toe, and yield, across all regions and directions. Human pericranium exhibits isotropic mechanical behavior that lies between that of the longitudinal and circumferential spinal dura. Further studies are required to determine if pericranium grafts behave like native dura under in vivo loading conditions. The Ogden parameters reported may be used for computational modeling of the central nervous system. Graphical abstract.

Proposal of a Management Algorithm to Predict the Need for Expansion Duraplasty in American Spinal Injury Association Impairment Scale Grades A-C Traumatic Cervical Spinal Cord Injury Patients

Expansion duraplasty to reopen effaced subarachnoid space and improve spinal cord perfusion, autoregulation, and spinal pressure reactivity index (sPRX) has been advocated in patients with traumatic cervical spinal cord injury (tCSCI). We designed this study to identify candidates for expansion duraplasty, based on the absence of cerebrospinal fluid (CSF) interface around the spinal cord on magnetic resonance imaging (MRI), in the setting of otherwise adequate bony decompression. Over a 61-month period, 104 consecutive American Spinal Injury Association Impairment Scale (AIS) grades A-C patients with tCSCI had post-operative MRI to assess the adequacy of surgical decompression. Their mean age was 53.4 years, and 89% were male. Sixty-one patients had falls, 31 motor vehicle collisions, 11 sport injuries, and one an assault. The AIS grade was A in 56, B in 18, and C in 30 patients. Fifty-four patients had fracture dislocations; there was no evidence of skeletal injury in 50 patients. Mean intramedullary lesion length (IMLL) was 46.9 (standard deviation = 19.4) mm. Median time from injury to decompression was 17 h (interquartile range 15.2 h). After surgery, 94 patients had adequate decompression as judged by the presence of CSF anterior and posterior to the spinal cord, whereas 10 patients had effacement of the subarachnoid space at the injury epicenter. In two patients whose decompression was not definitive and post-operative MRI indicated inadequate decompression, expansion duraplasty was performed. Candidates for expansion duraplasty (i.e., those with inadequate decompression) were significantly younger (p < 0.0001), were AIS grade A (p < 0.0016), had either sport injuries (six patients) or motor vehicle collisions (three patients) (p < 0.0001), had fracture dislocation (p = 0.00016), and had longer IMLL (p = 0.0097). In regression models, patients with sport injuries and inadequate decompression were suitable candidates for expansion duraplasty (p = 0.03). Further, 9.6% of patients failed bony decompression alone and either did (2) or would have (8) benefited from expansion duraplasty.

Multimodal interventions to optimize spinal cord perfusion in patients with acute traumatic spinal cord injuries: a systematic review

OBJECTIVE

The authors systematically reviewed current evidence for the utility of mean arterial pressure (MAP), intraspinal pressure (ISP), and spinal cord perfusion pressure (SCPP) as predictors of outcomes after traumatic spinal cord injury (SCI).

METHODS

PubMed, Cochrane Reviews Library, EMBASE, and Scopus databases were queried in December 2020. Two independent reviewers screened articles using Covidence software. Disagreements were resolved by a third reviewer. The inclusion criteria for articles were 1) available in English; 2) full text; 3) clinical studies on traumatic SCI interventions; 4) involved only human participants; and 5) focused on MAP, ISP, or SCPP. Exclusion criteria were 1) only available in non-English languages; 2) focused only on the brain; 3) described spinal diseases other than SCI; 4) interventions altering parameters other than MAP, ISP, or SCPP; and 5) animal studies. Studies were analyzed qualitatively and grouped into two categories: interventions increasing MAP or interventions decreasing ISP. The Scottish Intercollegiate Guidelines Network level of evidence was used to assess bias and the Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate confidence in the anticipated effects of each outcome.

RESULTS

A total of 2540 unique articles were identified, of which 72 proceeded to full-text review and 24 were included in analysis. One additional study was included retrospectively. Articles that went through full-text review were excluded if they were a review paper (n = 12), not a full article (n = 12), a duplicate paper (n = 9), not a human study (n = 3), not in English (n = 3), not pertaining to traumatic SCI (n = 3), an improper intervention (n = 3), without intervention (n = 2), and without analysis of intervention (n = 1). Although maintaining optimal MAP levels is the current recommendation for SCI management, the published literature supports maintenance of SCPP as a stronger indicator of favorable outcomes. Studies also suggest that laminectomy and durotomy may provide better outcomes than laminectomy alone, although higher-level studies are needed. Current evidence is inconclusive on the effectiveness of CSF drainage for reducing ISP.

CONCLUSIONS

This review demonstrates the importance of assessing how different interventions may vary in their ability to optimize SCPP.

Significance of spinal cord perfusion pressure following spinal cord injury: A systematic scoping review

This scoping review systematically reviewed relevant research to summarize the literature addressing the significance of monitoring spinal cord perfusion pressure (SCPP) in acute traumatic spinal cord injury (SCI). The objectives of the review were to (1) examine the nature of research in the field of SCPP monitoring in SCI, (2) summarize the key research findings in the field, and (3) identify research gaps in the existing literature and future research priorities. Primary literature searches were conducted using databases (Medline and Embase) and expanded searches were conducted by reviewing the references of eligible articles and searches of Scopus, Web of Science core collection, Google Scholar, and conference abstracts. Relevant data were extracted from the studies and synthesis of findings was guided by the identification of patterns across studies to identify key themes and research gaps within the literature. Following primary and expanded searches, a total of 883 articles were screened. Seventy-three articles met the review inclusion criteria, including 34 original research articles. Other articles were categorized as conference abstracts, literature reviews, systematic reviews, letters to the editor, perspective articles, and editorials. Key themes relevant to the research question that emerged from the review included the relationship between SCPP and neurological recovery, the safety of monitoring pressures within the intrathecal space, and methods of intervention to enhance SCPP in the setting of acute traumatic SCI. Original research that aims to enhance SCPP by targeting increases in mean arterial pressure or reducing pressure in the intrathecal space is reviewed. Further discussion regarding where pressure within the intrathecal space should be measured is provided. Finally, we highlight research gaps in the literature such as determining the feasibility of invasive monitoring at smaller centers, the need for a better understanding of cerebrospinal fluid physiology following SCI, and novel pharmacological interventions to enhance SCPP in the setting of acute traumatic SCI. Ultimately, despite a growing body of literature on the significance of SCPP monitoring following SCI, there are still a number of important knowledge gaps that will require further investigation.

Expression and regulatory network of long noncoding RNA in rats after spinal cord hemisection injury

Long noncoding RNAs (lncRNAs) participate in a variety of biological processes and diseases. However, the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed. In this study of right side hemisection of the spinal cord at T10, we detected the expression of lncRNAs in the proximal tissue of T10 lamina at different time points and found 445 lncRNAs and 6522 mRNA were differentially expressed. We divided the differentially expressed lncRNAs into 26 expression trends and analyzed Profile 25 and Profile 2, the two expression trends with the most significant difference. Our results showed that the expression of 68 lncRNAs in Profile 25 rose first and remained high 3 days post-injury. There were 387 mRNAs co-expressed with the 68 lncRNAs in Profile 25. The co-expression network showed that the co-expressed genes were mainly enriched in cell division, inflammatory response, FcγR-mediated cell phagocytosis signaling pathway, cell cycle and apoptosis. The expression of 56 lncRNAs in Profile2 first declined and remained low after 3 days post-injury. There were 387 mRNAs co-expressed with the 56 lncRNAs in Profile 2. The co-expression network showed that the co-expressed genes were mainly enriched in the chemical synaptic transmission process and in the signaling pathway of neuroactive ligand-receptor interaction. The results provided the expression and regulatory network of the main lncRNAs after spinal cord injury and clarified their co-expressed gene enriched biological processes and signaling pathways. These findings provide a new direction for the clinical treatment of spinal cord injury.

Fibrotic Scar in CNS Injuries: From the Cellular Origins of Fibroblasts to the Molecular Processes of Fibrotic Scar Formation

Central nervous system (CNS) trauma activates a persistent repair response that leads to fibrotic scar formation within the lesion. This scarring is similar to other organ fibrosis in many ways; however, the unique features of the CNS differentiate it from other organs. In this review, we discuss fibrotic scar formation in CNS trauma, including the cellular origins of fibroblasts, the mechanism of fibrotic scar formation following an injury, as well as the implication of the fibrotic scar in CNS tissue remodeling and regeneration. While discussing the shared features of CNS fibrotic scar and fibrosis outside the CNS, we highlight their differences and discuss therapeutic targets that may enhance regeneration in the CNS.

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.

Established and Emerging Therapies in Acute Spinal Cord Injury

Acute spinal cord injury (SCI) is devastating for patients and their caretakers and has an annual incidence of 20–50 per million people. Following initial assessment with appropriate physical examination and imaging, patients who are deemed surgical candidates should undergo decompression with stabilization. Earlier intervention can improve neurological recovery in the post-operative period while allowing earlier mobilization. Optimized medical management is paramount to improve outcomes. Emerging strategies for managing SCI in the acute period stem from an evolving understanding of the pathophysiology of the injury. General areas of focus include ischemia prevention, reduction of secondary injury due to inflammation, modulation of the cytotoxic and immune response, and promotion of cellular regeneration. In this article, we review established, emerging, and novel experimental therapies. Continued translational research on these methods will improve the feasibility of bench-to-bedside innovations in treating patients with acute SCI.

The past, present, and future of traumatic spinal cord injury therapies: a review

This review provides a concise outline of the advances made in the care of patients and to the quality of life after a traumatic spinal cord injury (SCI) over the last century. Despite these improvements reversal of the neurological injury is not yet possible. Instead, current treatment is limited to providing symptomatic relief, avoiding secondary insults and preventing additional sequelae. However, with an ever-advancing technology and deeper understanding of the damaged spinal cord, this appears increasingly conceivable. A brief synopsis of the most prominent challenges facing both clinicians and research scientists in developing functional treatments for a progressively complex injury are presented. Moreover, the multiple mechanisms by which damage propagates many months after the original injury requires a multifaceted approach to ameliorate the human spinal cord. We discuss potential methods to protect the spinal cord from damage, and to manipulate the inherent inhibition of the spinal cord to regeneration and repair. Although acute and chronic SCI share common final pathways resulting in cell death and neurological deficits, the underlying putative mechanisms of chronic SCI and the treatments are not covered in this review.

Elevated intraspinal pressure in traumatic spinal cord injury is a promising therapeutic target

The currently recommended management for acute traumatic spinal cord injury aims to reduce the incidence of secondary injury and promote functional recovery. Elevated intraspinal pressure (ISP) likely plays an important role in the processes involved in secondary spinal cord injury, and should not be overlooked. However, the factors and detailed time course contributing to elevated ISP and its impact on pathophysiology after traumatic spinal cord injury have not been reviewed in the literature. Here, we review the etiology and progression of elevated ISP, as well as potential therapeutic measures that target elevated ISP. Elevated ISP is a time-dependent process that is mainly caused by hemorrhage, edema, and blood-spinal cord barrier destruction and peaks at 3 days after traumatic spinal cord injury. Duraplasty and hypertonic saline may be promising treatments for reducing ISP within this time window. Other potential treatments such as decompression, spinal cord incision, hemostasis, and methylprednisolone treatment require further validation.

Monitoring Spinal Cord Tissue Oxygen in Patients With Acute, Severe Traumatic Spinal Cord Injuries

Objectives

To determine the feasibility of monitoring tissue oxygen tension from the injury site (psctO2) in patients with acute, severe traumatic spinal cord injuries.

Design

We inserted at the injury site a pressure probe, a microdialysis catheter, and an oxygen electrode to monitor for up to a week intraspinal pressure (ISP), spinal cord perfusion pressure (SCPP), tissue glucose, lactate/pyruvate ratio (LPR), and psctO2. We analyzed 2,213 hours of such data. Follow-up was 6-28 months postinjury.

Setting

Single-center neurosurgical and neurocritical care units.

Subjects

Twenty-six patients with traumatic spinal cord injuries, American spinal injury association Impairment Scale A-C. Probes were inserted within 72 hours of injury.

Interventions

Insertion of subarachnoid oxygen electrode (Licox; Integra LifeSciences, Sophia-Antipolis, France), pressure probe, and microdialysis catheter.

Measurements and Main Results

psctO2 was significantly influenced by ISP (psctO2 26.7 +/- 0.3 mm Hg at ISP > 10 mmHg vs psctO2 22.7 +/- 0.8 mm Hg at ISP <= 10 mm Hg), SCPP (psctO2 26.8 +/- 0.3 mm Hg at SCPP < 90 mm Hg vs psctO2 32.1 +/- 0.7 mm Hg at SCPP >= 90 mm Hg), tissue glucose (psctO2 26.8 +/- 0.4 mm Hg at glucose < 6 mM vs 32.9 +/- 0.5 mm Hg at glucose >= 6 mM), tissue LPR (psctO2 25.3 +/- 0.4 mm Hg at LPR > 30 vs psctO2 31.3 +/- 0.3 mm Hg at LPR <= 30), and fever (psctO2 28.8 +/- 0.5 mm Hg at cord temperature 37-38[degrees]C vs psctO2 28.7 +/- 0.8 mm Hg at cord temperature >= 39[degrees]C). Tissue hypoxia also occurred independent of these factors. Increasing the FIO2 by 0.48 increases psctO2 by 71.8% above baseline within 8.4 minutes. In patients with motor-incomplete injuries, fluctuations in psctO2 correlated with fluctuations in limb motor score. The injured cord spent 11% (39%) hours at psctO2 less than 5 mm Hg (< 20 mm Hg) in patients with motor-complete outcomes, compared with 1% (30%) hours at psctO2 less than 5 mm Hg (< 20 mm Hg) in patients with motor-incomplete outcomes. Complications were cerebrospinal fluid leak (5/26) and wound infection (1/26).

Conclusions

This study lays the foundation for measuring and altering spinal cord oxygen at the injury site. Future studies are required to investigate whether this is an effective new therapy.

Management of Acute Traumatic Spinal Cord Injury: A Review of the Literature

Traumatic spinal cord injury (TSCI) is a debilitating disease that poses significant functional and economic burden on both the individual and societal levels. Prognosis is dependent on the extent of the spinal injury and the severity of neurological dysfunction. If not treated rapidly, patients with TSCI can suffer further secondary damage and experience escalating disability and complications. It is important to quickly assess the patient to identify the location and severity of injury to make a decision to pursue a surgical and/or conservative management. However, there are many conditions that factor into the management of TSCI patients, ranging from the initial presentation of the patient to long-term care for optimal recovery. Here, we provide a comprehensive review of the etiologies of spinal cord injury and the complications that may arise, and present an algorithm to aid in the management of TSCI.

Detection and Analysis of Perfusion Pressure through Measuring Oxygen Saturation and Requirement of Dural Incision Decompression after Laminectomy

BACKGROUND

Traumatic spinal cord injury (SCI) can continue and transform long after the time of initial injury. Preventing secondary injury after SCI is one of the most significant challenges, and early intervention to return the blood flow at the injury site can minimize the likelihood of secondary injury.

OBJECTIVE

The purpose of this study is to investigate whether laminectomy can achieve the spinal cord blood flow by measuring the spinal blood oxygen saturation intraoperatively without the presence of light.

METHODS

Between June and August 2021, eight patients were admitted after traumatic spinal cord injury for surgical treatment. We explored the effectiveness of laminectomy and whether the patients required further procedures or not. We used a brain oxygen saturation monitor at the spine injury site under dark conditions.

RESULTS

Eight cervical trauma patients, six males and two females, underwent laminectomy decompression. Three patients' ASIA grade improved by one level, and one patient showed slight motor-sensory improvement. Oxygen saturation was in the normal range.

CONCLUSION

Performing bony decompression can show good results. Therefore, finding an examination method to confirm the improvement of blood perfusion by measuring oxygen saturation at the injury site after laminectomy is essential to avoid other complications.

Acute, severe traumatic spinal cord injury: improving urinary bladder function by optimizing spinal cord perfusion

OBJECTIVE

The authors sought to investigate the effect of acute, severe traumatic spinal cord injury on the urinary bladder and the hypothesis that increasing the spinal cord perfusion pressure improves bladder function.

METHODS

In 13 adults with traumatic spinal cord injury (American Spinal Injury Association Impairment Scale grades A-C), a pressure probe and a microdialysis catheter were placed intradurally at the injury site. We varied the spinal cord perfusion pressure and performed filling cystometry. Patients were followed up for 12 months on average.

RESULTS

The 13 patients had 63 fill cycles; 38 cycles had unfavorable urodynamics, i.e., dangerously low compliance (< 20 mL/cmH2O), detrusor overactivity, or dangerously high end-fill pressure (> 40 cmH2O). Unfavorable urodynamics correlated with periods of injury site hypoperfusion (spinal cord perfusion pressure < 60 mm Hg), hyperperfusion (spinal cord perfusion pressure > 100 mm Hg), tissue glucose < 3 mM, and tissue lactate to pyruvate ratio > 30. Increasing spinal cord perfusion pressure from 67.0 ± 2.3 mm Hg (average ± SE) to 92.1 ± 3.0 mm Hg significantly reduced, from 534 to 365 mL, the median bladder volume at which the desire to void was first experienced. All patients with dangerously low average initial bladder compliance (< 20 mL/cmH2O) maintained low compliance at follow-up, whereas all patients with high average initial bladder compliance (> 100 mL/cmH2O) maintained high compliance at follow-up.

CONCLUSIONS

We conclude that unfavorable urodynamics develop within days of traumatic spinal cord injury, thus challenging the prevailing notion that the detrusor is initially acontractile. Urodynamic studies performed acutely identify patients with dangerously low bladder compliance likely to benefit from early intervention. At this early stage, bladder function is dynamic and is influenced by fluctuations in the physiology and metabolism at the injury site; therefore, optimizing spinal cord perfusion is likely to improve urological outcome in patients with acute severe traumatic spinal cord injury.

Medical Communication Services after Traumatic Spinal Cord Injury

It is difficult to assess and monitor the spinal cord injury (SCI) because of its pathophysiology after injury, with different degrees of prognosis and various treatment methods, including laminectomy, durotomy, and myelotomy. Medical communication services with different factors such as time of surgical intervention, procedure choice, spinal cord perfusion pressure (SCPP), and intraspinal pressure (ISP) contribute a significant role in improving neurological outcomes. This review aims to show the benefits of communication services and factors such as ISP, SCPP, and surgical intervention time in order to achieve positive long-term outcomes after an appropriate treatment method in SCI patients. The SCPP was found between 90 and 100 mmHg for the best outcome, MAP was found between 110 and 130 mmHg, and mean ISP is ≤20 mmHg after injury. Laminectomy alone cannot reduce the pressure between the dura and swollen cord. Durotomy and duroplasty considered as treatment choices after severe traumatic spinal cord injury (TSCI).

Rationally Designed, Self-Assembling, Multifunctional Hydrogel Depot Repairs Severe Spinal Cord Injury

Following severe spinal cord injury (SCI), dysregulated neuroinflammation causes neuronal and glial apoptosis, resulting in scar and cystic cavity formation during wound healing and ultimately the formation of an atrophic microenvironment that inhibits nerve regrowth. Because of this complex and dynamic pathophysiology, a systemic solution for scar- and cavity-free wound healing with microenvironment remodeling to promote nerve regrowth has rarely been explored. A one-step solution is proposed through a self-assembling, multifunctional hydrogel depot that punctually releases the anti-inflammatory drug methylprednisolone sodium succinate (MPSS) and growth factors (GFs) locally according to pathophysiology to repair severe SCI. Synergistically releasing the anti-inflammatory drug MPSS and GFs in the hydrogel depot throughout SCI pathophysiology protects spared tissues/axons from secondary injury, promotes scar boundary- and cavity-free wound healing, and results in permissive bridges for remarkable axonal regrowth. Behavioral and electrophysiological studies indicate that remnants of spared axons, not regenerating axons, mediate functional recovery, strongly suggesting that additional interventions are still required to render the rebuilt neuronal circuits functional. These findings pave the way for the development of a systemic solution to treat acute SCI.

A review of spinal cord perfusion pressure guided interventions in traumatic spinal cord injury

PURPOSE

To evaluate the causality between interventions on spinal cord perfusion pressure and neurological outcome in traumatic spinal cord injury.

METHODS

A systematic review was conducted in concordance with PRISMA guidelines. The literature was found in the EMBASE, PUBMED, SCOPUS, and WEB OF SCIENCE. Eligible studies included those that reported measurements and interventions on the spinal cord perfusion pressure in either animals or patients suffering from spinal cord injury. Only studies that reported a clinical or relevant clinical outcome measure (i.e., neurophysiology) were included.

RESULTS

The search yielded 795 unique records, and six studies were included after careful review. These studies suggested a positive correlation between spinal cord perfusion pressure and neurological outcome, but conclusions on causality could not be made.

CONCLUSION

In spite of growing indications that neurological outcomes are related to the spinal cord perfusion pressure in traumatic spinal cord injuries, a solid conclusion cannot be made due to the limited literature available. Additional well-designed studies are needed to address this issue.

Duraplasty in Traumatic Thoracic Spinal Cord Injury: Impact on Spinal Cord Hemodynamics, Tissue Metabolism, Histology, and Behavioral Recovery Using a Porcine Model

After acute traumatic spinal cord injury (SCI), the spinal cord can swell to fill the subarachnoid space and become compressed by the surrounding dura. In a porcine model of SCI, we performed a duraplasty to expand the subarachnoid space around the injured spinal cord and evaluated how this influenced acute intraparenchymal hemodynamic and metabolic responses, in addition to histological and behavioral recovery. Female Yucatan pigs underwent a T10 SCI, with or without duraplasty. Using microsensors implanted into the spinal cord parenchyma, changes in blood flow (ΔSCBF), oxygenation (ΔPO₂), and spinal cord pressure (ΔSCP) during and after SCI were monitored, alongside metabolic responses. Behavioral recovery was tested weekly using the Porcine Injury Behavior Scale (PTIBS). Thereafter, spinal cords were harvested for tissue sparing analyses. In both duraplasty and non-animals, the ΔSCP increased ∼5 mm Hg in the first 6 h post-injury. After this, the SCP appeared to be slightly reduced in the duraplasty animals, although the group differences were not statistically significant after controlling for injury severity in terms of impact force. During the first seven days post-SCI, the ΔSCBF or ΔPO₂ values were not different between the duraplasty and control animals. Over 12 weeks, there was no improvement in hindlimb locomotion as assessed by PTIBS scores and no reduction in tissue damage at the injury site in the duraplasty animals. In our porcine model of SCI, duraplasty did not provide any clear evidence of long-term behavioral or tissue sparing benefit after SCI.

Spinal Cord Perfusion Pressure Correlates with Anal Sphincter Function in a Cohort of Patients with Acute, Severe Traumatic Spinal Cord Injuries

Background

Acute, severe traumatic spinal cord injury often causes fecal incontinence. Currently, there are no treatments to improve anal function after traumatic spinal cord injury. Our study aims to determine whether, after traumatic spinal cord injury, anal function can be improved by interventions in the neuro-intensive care unit to alter the spinal cord perfusion pressure at the injury site.

Methods

We recruited a cohort of patients with acute, severe traumatic spinal cord injuries (American Spinal Injury Association Impairment Scale grades A–C). They underwent surgical fixation within 72 h of the injury and insertion of an intrathecal pressure probe at the injury site to monitor intraspinal pressure and compute spinal cord perfusion pressure as mean arterial pressure minus intraspinal pressure. Injury-site monitoring was performed at the neuro-intensive care unit for up to a week after injury. During monitoring, anorectal manometry was also conducted over a range of spinal cord perfusion pressures.

Results

Data were collected from 14 patients with consecutive traumatic spinal cord injury aged 22–67 years. The mean resting anal pressure was 44 cmH₂O, which is considerably lower than the average for healthy patients, previously reported at 99 cmH₂O. Mean resting anal pressure versus spinal cord perfusion pressure had an inverted U-shaped relation (Ȓ² = 0.82), with the highest resting anal pressures being at a spinal cord perfusion pressure of approximately 100 mmHg. The recto-anal inhibitory reflex (transient relaxation of the internal anal sphincter during rectal distension), which is important for maintaining fecal continence, was present in 90% of attempts at high (90 mmHg) spinal cord perfusion pressure versus 70% of attempts at low (60 mmHg) spinal cord perfusion pressure (P < 0.05). During cough, the rise in anal pressure from baseline was 51 cmH₂O at high (86 mmHg) spinal cord perfusion pressure versus 37 cmH₂O at low (62 mmHg) spinal cord perfusion pressure (P < 0.0001). During anal squeeze, higher spinal cord perfusion pressure was associated with longer endurance time and spinal cord perfusion pressure of 70–90 mmHg was associated with stronger squeeze. There were no complications associated with anorectal manometry.

Conclusions

Our data indicate that spinal cord injury causes severe disruption of anal sphincter function. Several key components of anal continence (resting anal pressure, recto-anal inhibitory reflex, and anal pressure during cough and squeeze) markedly improve at higher spinal cord perfusion pressure. Maintaining too high of spinal cord perfusion pressure may worsen anal continence.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01232-1.

Selenium-Binding Protein 1 (SELENBP1) as Biomarker for Adverse Clinical Outcome After Traumatic Spinal Cord Injury

Introduction: Traumatic spinal cord injury (TSCI) presents a diagnostic challenge as it may have dramatic consequences for the affected patient. Additional biomarkers are needed for improved care and personalized therapy.

Objective: Serum selenium binding protein 1 (SELENBP1) has been detected in myocardial infarction, reflecting hypoxic tissue damage and recovery odds. As SELENBP1 is usually not detected in the serum of healthy subjects, we tested the hypothesis that it may become detectable in TSCI and indicate tissue damage and regeneration odds.

Methods: In this prospective observational study, patients with comparable injuries were allocated to three groups; vertebral body fractures without neurological impairment (control “C”), TSCI without remission (“G0”), and TSCI with signs of remission (“G1”). Consecutive serum samples were available from different time points and analyzed for SELENBP1 by sandwich immunoassay, for trace elements by X-ray fluorescence and for cytokines by multiplex immunoassays.

Results: Serum SELENBP1 was elevated at admission in relation to the degree of neurological impairment [graded as A, B, C, or D according to the American Spinal Injury Association (AISA) impairment scale (AIS)]. Patients with the most severe neurological impairment (classified as AIS A) exhibited the highest SELENBP1 concentrations (p = 0.011). During the first 3 days, SELENBP1 levels differed between G0 and G1 (p = 0.019), and dynamics of SELENBP1 correlated to monocyte chemoattractant protein 1, chemokine ligand 3 and zinc concentrations.

Conclusion: Circulating SELENBP1 concentrations are related to the degree of neurological impairment in TSCI and provide remission odds information. The tight correlation of SELENBP1 with CCL2 levels provides a novel link between Se metabolism and immune cell activation, with potential relevance for neurological damage and regeneration processes, respectively.

Acute, Severe Traumatic Spinal Cord Injury: Monitoring from the Injury Site and Expansion Duraplasty

We discuss 2 evolving management options for acute spinal cord injury that hold promise to further improve outcome: pressure monitoring from the injured cord and expansion duraplasty. Probes surgically implanted at the injury site can transduce intraspinal pressure, spinal cord perfusion pressure, and cord metabolism. Intraspinal pressure is not adequately reduced by bony decompression alone because the swollen, injured cord is compressed against the dura. Expansion duraplasty may be necessary to effectively decompress the injured cord. A randomized controlled trial called DISCUS is investigating expansion duraplasty as a novel treatment for acute, severe traumatic cervical spinal cord injury.

Efficacy of Early (≤ 24 Hours), Late (25-72 Hours), and Delayed (>72 Hours) Surgery with Magnetic Resonance Imaging-Confirmed Decompression in American Spinal Injury Association Impairment Scale Grades C and D Acute Traumatic Central Cord Syndrome Caused by Spinal Stenosis

The therapeutic significance of timing of decompression in acute traumatic central cord syndrome (ATCCS) caused by spinal stenosis remains unsettled. We retrospectively examined a homogenous cohort of patients with ATCCS and magnetic resonance imaging (MRI) evidence of post-treatment spinal cord decompression to determine whether timing of decompression played a significant role in American Spinal Injury Association (ASIA) motor score (AMS) 6 months following trauma. We used the t test, analysis of variance, Pearson correlation coefficient, and multiple regression for statistical analysis. During a 19-year period, 101 patients with ATCCS, admission ASIA Impairment Scale (AIS) grades C and D, and an admission AMS of ≤95 were surgically decompressed. Twenty-four of 101 patients had an AIS grade C injury. Eighty-two patients were males, the mean age of patients was 57.9 years, and 69 patients had had a fall. AMS at admission was 68.3 (standard deviation [SD] 23.4); upper extremities (UE) 28.6 (SD 14.7), and lower extremities (LE) 41.0 (SD 12.7). AMS at the latest follow-up was 93.1 (SD 12.8), UE 45.4 (SD 7.6), and LE 47.9 (SD 6.6). Mean number of stenotic segments was 2.8, mean canal compromise was 38.6% (SD 8.7%), and mean intramedullary lesion length (IMLL) was 23 mm (SD 11). Thirty-six of 101 patients had decompression within 24 h, 38 patients had decompression between 25 and 72 h, and 27 patients had decompression >72 h after injury. Demographics, etiology, AMS, AIS grade, morphometry, lesion length, surgical technique, steroid protocol, and follow-up AMS were not statistically different between groups treated at different times. We analyzed the effect size of timing of decompression categorically and in a continuous fashion. There was no significant effect of the timing of decompression on follow-up AMS. Only AMS at admission determined AMS at follow-up (coefficient = 0.31; 95% confidence interval [CI]:0.21; p = 0.001). We conclude that timing of decompression in ATCCS caused by spinal stenosis has little bearing on ultimate AMS at follow-up.