Spinal Cord Perfusion Research Articles

Cerebrospinal fluid drain placement and comprehensive strategies for spinal cord protection in open thoracoabdominal aortic aneurysm repair.

Ischaemic spinal cord injury remains a significant challenge in thoracoabdominal aortic repairs. Modern techniques have reduced spinal cord injury rates yet managing patients during and after thoracoabdominal aortic repairs remains complex. This article outlines our comprehensive approach to the prevention of spinal cord injuries in open thoracoabdominal aortic repair operations, focusing on the placement of cerebrospinal fluid drain and intraoperative strategies to enhance spinal cord protection. Preoperative planning involves thorough patient assessment, prehabilitation and nutritional support, detailed imaging review, thorough operative planning and patient blood management. Intraoperative measures include the use of neuromonitoring techniques like near-infrared spectroscopy and motor evoked potentials, as well as cerebrospinal fluid drainage together with blood pressure management to optimize spinal cord perfusion. Postoperative management focuses on maintaining haemodynamic stability with high mean arterial pressure, along with close monitoring and management of the cerebrospinal fluid drain to improve spinal cord perfusion. Additionally, thromboelastography-guided strategies are crucial for optimizing coagulation and addressing postoperative bleeding complications. The goal of this multifaceted approach is to minimize the risk of spinal cord injury, thereby improving patient outcomes and reducing the incidence of postoperative paraplegia. Our video tutorial shows some of our preoperative and intraoperative techniques for spinal cord protection in thoracoabdominal aortic repairs.

Characterization of cerebrospinal fluid markers as indicators of spinal cord ischemia following an endovascular aortic aneurysm repair procedure.

Spinal cord ischemia (SCI) remains one of the most devastating complications in both open and endovascular stent graft repair of thoracoabdominal aortic aneurysms. The endovascular aortic aneurysm repair (EVAR) can be either thoracic (TEVAR) when it targets the thoracic aortic aneurysm or fenestrated branched when repair involves the visceral and/or renal arteries. Even though EVAR interventions are less invasive than open repair, they are still associated with a significant risk of SCI. The current primary strategy to prevent SCI after TEVAR is to increase and/or maintain spinal cord perfusion pressure (blood flow) by increasing the mean arterial pressure while simultaneously draining CSF. Although the benefit of CSF drainage in EVAR procedures remains uncertain, it provides an opportunity to study the changes in cytokine and oxidative stress markers that may signal the pathophysiology of SCI following EVAR. The aim of this study was to evaluate the temporal relationship between stent deployment and CSF cytokine and oxidative stress marker levels as predictors of delayed SCI in patients undergoing an EVAR procedure. There were 16 EVAR cases across 15 patients enrolled in this study, with 1 patient undergoing the procedure twice 1 year apart. The levels of oxidative stress (8-hydroxy-2'-deoxyguanosine [8-OHdG], glial fibrillary acidic [GFAP], and lactic acid) and proinflammatory (tumor necrosis factor-alpha [TNF-α], interleukin (IL)-6, and IL-1β) and antiinflammatory (IL-4) markers were quantified at different time points between 0 and 48 hours after EVAR by enzyme-linked immunosorbent assay. The changes in protein levels of both oxidative stress and inflammatory markers were expressed as fold change from the time of the lumbar drain insertion prior to surgery. Following the EVAR procedure, 8-OHdG resulted in the highest upregulation at later time points postoperatively (48 hours) and this increase was positively correlated with TNF-α level. The data also revealed that IL-6 peaked during the stent deployment intervention and this pattern of expression was positively correlated with the expression of lactic acid. No significant changes were noted in the expression levels of GFAP, lactic acid, and IL-1β. There appears to be a temporal relationship between lumbar CSF drainage and CSF cytokines and oxidative stress markers that may help 1) identify patients at risk for developing delayed SCI and 2) modify patient management to prevent the damage from delayed SCI.

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

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. 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. 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. 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.

Clinical Assessment and Management of Acute Spinal Cord Injury.

The information contained in this article is suitable for clinicians practicing in the United States desiring a general overview of the assessment and management of spinal cord injury (SCI), focusing on initial care, assessment, acute management, complications, prognostication, and future research directions. SCI presents significant challenges, affecting patients physically, emotionally, and financially, with variable recovery outcomes ranging from full functionality to lifelong dependence on caregivers. Initial care aims to minimize secondary injury through thorough neurological evaluations and imaging studies to assess the severity of the injury. Acute management prioritizes stabilizing respiratory and cardiovascular functions and maintaining proper spinal cord perfusion. Patients with unstable or progressive neurological decline benefit from timely surgical intervention to optimize neurological recovery. Subacute management focuses on addressing common complications affecting the respiratory, gastrointestinal, and genitourinary systems, emphasizing a holistic, multidisciplinary approach. Prognostication is currently based on neurological assessments and imaging findings, but emerging biomarkers offer the potential to refine outcome predictions further. Additionally, novel therapeutic interventions, such as hypothermia therapy and neuroprotective medications are being explored to mitigate secondary damage and enhance recovery. This paper serves as a high-yield refresher for clinicians for the assessment and management of acute spinal cord injury during index admission.

Pre-operative spinal cord perfusion quantified by DSC MRI as a predictor of post-operative prognosis in patients with cervical spondylotic myelopathy.

This study aims to investigate the potential of preoperative blood supply condition measured by dynamic susceptibility contract (DSC) MRI in prediction of postoperative outcomes for patients with cervical spondylotic myelopathy (CSM). Thirty-nine patients (Age: 61 ± 7, male: 23, female: 16) with CSM who underwent laminoplasty were enrolled. All patients received DSC MRI before the operation. Five parameters include Enhance, rEnhance, full width at half maxima (FWHM), Slope1 and Slope2 in DSC MRI, were calculated at all the compressed spinal cord segments. Clinical outcomes were evaluated by modified Japanese Orthopaedic Association (mJOA) scores. Patients were divided into two groups based on mJOA recovery rate of 5years: good recovery (> 50%) or poor recovery (≤ 50%). The difference between two groups were compared. The value of DSC MRI to CSM was evaluated by logistic and receiver operating characteristic (ROC) curve analysis. There were 26 patients in good recovery group and 13 patients in poor recovery group. The baseline characteristics, including age, gender, preoperative mJOA score, and smoking status showed no significant difference between the two groups (all p > 0.05). The FWHM was significantly higher in the poor recovery group (9.77 ± 2.78) compared to the good recovery group (6.64 ± 1.65) (p = 0.002). Logistic regression analysis indicated that an increased FWHM was a significant risk factor for poor prognosis recovery (p = 0.013, OR = 0.392, 95%CI: 0.187-0.822). The AUC of FWHM for ROC was 0.843 (95% CI: 0.710-0.975) with a p value of 0.001. In addition, an FWHM greater than 5.87, with a sensitivity of 92.3% and specificity of 69.2%, was found to be an independent risk factor for poor postoperative recovery in patients with CSM. In this study, we successfully quantified the spinal cord blood supply condition by DSC MRI technique. We found that an increase in FWHM was an independent risk factor for poor postoperative recovery in CSM patients. Specifically, patients with FWHM > 5.87 have a poor postoperative recovery.

A novel minimally invasive and versatile kyphoplasty balloon-based model of porcine spinal cord injury.

Spinal cord injury (SCI) animal models often utilize an open surgical laminectomy, which results in animal morbidity and also leads to changes in spinal canal diameter, spinal cord perfusion, cerebrospinal fluid flow dynamics, and spinal stability which may confound SCI research. Moreover, the use of open surgical laminectomy for injury creation lacks realism when considering human SCI scenarios. We developed a novel, image-guided, minimally invasive, large animal model of SCI which utilizes a kyphoplasty balloon inserted into the epidural space via an interlaminar approach without the need for open surgery. The model was validated in 5 Yucatán pigs with imaging, neurofunctional, histologic, and electrophysiologic findings consistent with a mild compression injury. Few large animal models exist that have the potential to reproduce the mechanisms of spinal cord injury (SCI) commonly seen in humans, which in turn limits the relevance and applicability of SCI translational research. SCI research relies heavily on animal models, which typically involve an open surgical, dorsal laminectomy which is inherently invasive and may have untoward consequences on animal morbidity and spinal physiology that limit translational impact. We developed a minimally invasive, large animal model of spinal cord injury which utilizes a kyphoplasty balloon inserted percutaneously into the spinal epidural space. Balloon inflation results in a targeted, compressive spinal cord injury with histological and electrophysiological features directly relevant to human spinal cord injury cases without the need for invasive surgery. Balloon inflation pressure, length of time that balloon remains inflated, and speed of inflation may be modified to achieve variations in injury severity and subtype.

Critical Care of Spinal Cord Injury.

Spinal cord injury (SCI) is a major cause of morbidity and mortality, posing a significant financial burden on patients and the healthcare system. While little can be done to reverse the primary mechanical insult, minimizing secondary injury due to ischemia and inflammation and avoiding complications that adversely affect neurologic outcome represent major goals of management. This article reviews important considerations in the acute critical care management of SCI to improve outcomes. Neuroprotective agents, such as riluzole, may allow for improved neurologic recovery but require further investigation at this time. Various forms of neuromodulation, such as transcranial magnetic stimulation, are currently under investigation. Early decompression and stabilization of SCI is recommended within 24h of injury when indicated. Spinal cord perfusion may be optimized with a mean arterial pressure goal from a lower limit of 75-80 to an upper limit of 90-95mmHg for 3-7days after injury. The use of corticosteroids remains controversial; however, initiation of a 24-h infusion of methylprednisolone 5.4mg/kg/hour within 8h of injury has been found to improve motor scores. Attentive pulmonary and urologic care along with early mobilization can reduce in-hospital complications.

Retrospective Analysis of Paraparalysis/Paraparesis Post Aortic Aneurysm Endovascular Repair

Abstract Objective Paralysis post TEVAR is a challenging complication, this study discusses its incidence, Risk factors, clinical outcome, reversibility, protective strategy and associated mortality. Methods Retrospective study Conducted on patients underwent thoracic and thoracoabdominal aortic Aneurysm Endovascular Repair in Last 11 years (January 2012 till June 2022) in single center as regard incidence, personal history, medical and surgical risk factors, preventive strategies, reversibility of paralysis and associated mortality. Data was obtained from records; paralysis was diagnosed through clinical examination immediately after emergence from anesthesia and frequently post operatively in SICU or even word and after discharge in follow-up outpatient clinic visits. Results A study carried on 137 patients, 15 patients of them developed lower limb paralysis with incidence of 10.9%, 3 patients of them (23.1%) developed paralysis immediately post operative, 4 patients developed paralysis in day 1 post operative (30.8%). And the rest of patients developed delayed onset paralysis (more than 24 Hour post procedure), The latest one developed paralysis 26 days post operative, 8 of paralyzed patients had spinal cord imaging (MRI) 4 of them (50%) didn’t show any abnormality and 3 of them (37.5%) showed spinal cord ischemia and 1 patient didn’t tolerate the MRI machine so the study was discontinued. According to reversibility, 9 patients had complete reversal of their motor and sensory symptoms to the baseline preoperative status. 2 patients had partial reversal of their symptoms, and 4 patients had persistent symptoms without any improvement despite the routine management that included elevating MAP and draining CSF to less than 10 mmHg in order to maintain spinal cord perfusion pressure at level of 80 mmHg and giving naloxone. Data showed 12 out of 81 patients (14.8%) who had functioning spinal drain developed paralysis. Duration of procedure is the most affecting risk factor on paralysis, patients with mean duration of 270 minutes had higher risk of paralysis. Conclusion Prediction of paralysis post TEVAR is still difficult and data analysis showed that the duration of procedure is the only statistically significant variable that we can rely on.

Microbubble Contrast-Enhanced Transcutaneous Ultrasound Enables Real-Time Spinal Cord Perfusion Monitoring Following Posterior Cervical Decompression

Ultrasound imaging is inexpensive, portable, and widely available. The development of a real-time transcutaneous spinal cord perfusion monitoring system would allow more precise targeting of mean arterial pressure goals following acute spinal cord injury (SCI). There has been no prior demonstration of successful real-time cord perfusion monitoring in humans. Four adult patients who had undergone posterior cervical decompression and instrumentation at a single center were enrolled into this prospective feasibility study. All participants had undergone cervical laminectomies spanning ≥2 contiguous levels ≥2months prior to inclusion with no history of SCI. The first 2 underwent transcutaneous ultrasound without contrast and the second 2 underwent contrast-enhanced ultrasound (CEUS) with intravenously injected microbubble contrast. Using noncontrast ultrasound with or without Doppler (n= 2), the dura, spinal cord, and vertebral bodies were apparent however ultrasonography was insufficient to discern intramedullary perfusion or clear white-gray matter differentiation. With application of microbubble contrast (n= 2), it was possible to quantify differential spinal cord perfusion within and between cross-sectional regions of the cord. Further, it was possible to quantify spinal cord hemodynamic perfusion using CEUS by measuring peak signal intensity and the time to peak signal intensity after microbubble contrast injection. Time-intensity curves were generated and area under the curves were calculated as a marker of tissue perfusion. CEUS is a viable platform for monitoring real-time cord perfusion in patients who have undergone prior cervical laminectomies. Further development has the potential to change clinical management acute SCI by tailoring treatments to measured tissue perfusion parameters.

Contrast enhanced ultrasound for traumatic spinal cord injury: an overview of current and future applications

Study designSystematic review.ObjectiveContrast-enhanced ultrasound (CEUS) is an imaging modality that has only recently seen neurosurgical application. CEUS uses inert microbubbles to intraoperatively visualize vasculature and perfusion of the brain and spinal cord in real time. Observation and augmentation of spinal cord perfusion is vital component of the management of traumatic spinal cord injury, yet there are limited imaging modalities to evaluate spinal cord perfusion. CEUS provides an intraoperative imaging tool to evaluate spinal cord perfusion in real time. The objective of this review is to evaluate the current literature on the various applications and benefits of CEUS in traumatic spinal cord injury.SettingSouth Carolina, USA.MethodsThis review was written according to the PRISMA 2020 guidelines.Results143 articles were found in our literature search, with 46 of them being unique. After excluding articles for relevance to CEUS and spinal cord injury, we were left with 10 papers. Studies in animal models have shown CEUS to be an effective non-invasive imaging modality that can detect perfusion changes of injured spinal cords in real time.ConclusionThis imaging modality can provide object perfusion data of the nidus of injury, surrounding penumbra and healthy neural tissue in a traumatized spinal cord. Investigation in its use in humans is ongoing and remains promising to be an effective diagnostic and prognostic tool for those suffering from spinal cord injury.

Advances in Medical and Surgical Care of Acute Spinal Cord injury

Acute cervical spinal cord injury (SCI) represents a significant challenge, with substantial implications for individual well-being and societal costs. In this chapter, we highlighted the importance of early surgical intervention within a critical time frame following injury to mitigate the risk of secondary damage and optimize neurological recovery. The chapter also delineated the dichotomy of primary and secondary injuries in traumatic cervical SCI, elucidating the pathophysiological mechanisms underlying each phase. Insights into the inflammatory cascade and cellular responses offer a nuanced understanding of injury progression, paving the way for targeted therapeutic interventions. Therefore, we delved into the current landscape of traumatic cervical SCI, addressing the advances in the medical and surgical care. Regarding surgical management, attention was directed towards established practices such as immobilization, respiratory support, and optimal timing of surgery, alongside emerging modalities including intraspinal pressure management, stem cell therapy, and nerve/tendon transfer. Similarly, the medical management section highlighted the importance of spinal cord perfusion, neurogenic shock management, and the role of steroids, while also exploring novel avenues such as genetic modification for spinal recovery. Overall, this chapter underscored the dynamic nature of SCI care, advocating for a holistic approach that integrates traditional and innovative treatment modalities.

Alpha 2-adrenoceptor participates in anti-hyperalgesia by regulating metabolic demand.

The α2-adrenoceptor agonist dexmedetomidine is a commonly used drug for sedatives in clinics and has analgesic effects; however, its mechanism of analgesia in the spine remains unclear. In this study, we systematically used behavioural and transcriptomic sequencing, pharmacological intervention, electrophysiological recording and ultrasound imaging to explore the analgesic effects of the α2-adrenoceptor and its molecular mechanism. Firstly, we found that spinal nerve injury changed the spinal transcriptome expression, and the differential genes were mainly related to calcium signalling and tissue metabolic pathways. In addition, α2-adrenoceptor mRNA expression was significantly upregulated, and α2-adrenoceptor was significantly colocalised with markers, particularly neuronal markers. Intrathecal dexmedetomidine suppressed neuropathic pain and acute inflammatory pain in a dose-dependent manner. The transcriptome results demonstrated that the analgesic effect of dexmedetomidine may be related to the modulation of neuronal metabolism. Weighted gene correlation network analysis indicated that turquoise, brown, yellow and grey modules were the most correlated with dexmedetomidine-induced analgesic effects. Bioinformatics also annotated the involvement of metabolic processes and neural plasticity. A cardiovascular-mitochondrial interaction was found, and ultrasound imaging revealed that injection of dexmedetomidine significantly enhanced spinal cord perfusion in rats with neuropathic pain, which might be regulated by pyruvate dehydrogenase kinase 4 (pdk4), cholesterol 25-hydroxylase (ch25h) and GTP cyclohydrolase 1 (gch1). Increasing the perfusion doses of dexmedetomidine significantly suppressed the frequency and amplitude of spinal nerve ligation-induced miniature excitatory postsynaptic currents. Overall, dexmedetomidine exerts analgesic effects by restoring neuronal metabolic processes through agonism of the α2-adrenoceptor and subsequently inhibiting changes in synaptic plasticity.

Interventions to Optimize Spinal Cord Perfusion in Patients With Acute Traumatic Spinal Cord Injury: An Updated Systematic Review.

Systematic review update. Interventions that aim to optimize spinal cord perfusion are thought to play an important role in minimizing secondary ischemic damage and improving outcomes in patients with acute traumatic spinal cord injuries (SCIs). However, exactly how to optimize spinal cord perfusion and enhance neurologic recovery remains controversial. We performed an update of a recent systematic review (Evaniew et al, J. Neurotrauma 2020) to evaluate the effects of Mean Arterial Pressure (MAP) support or Spinal Cord Perfusion Pressure (SCPP) support on neurological recovery and rates of adverse events among patients with acute traumatic SCI. We searched PubMed/MEDLINE, EMBASE and ClinicalTrials.gov for new published reports. Two reviewers independently screened articles, extracted data, and evaluated risk of bias. We implemented the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach to rate confidence in the quality of the evidence. From 569 potentially relevant new citations since 2019, we identified 9 new studies for inclusion, which were combined with 19 studies from a prior review to give a total of 28 studies. According to low or very low quality evidence, the effect of MAP support on neurological recovery is uncertain, and increased SCPP may be associated with improved neurological recovery. Both approaches may involve risks for specific adverse events, but the importance of these adverse events to patients remains unclear. Very low quality evidence failed to yield reliable guidance about particular monitoring techniques, perfusion ranges, pharmacological agents, or durations of treatment. This update provides an evidence base to support the development of a new clinical practice guideline for the hemodynamic management of patients with acute traumatic SCI. While avoidance of hypotension and maintenance of spinal cord perfusion are important principles in the management of an acute SCI, the literature does not provide high quality evidence in support of a particular protocol. Further prospective, controlled research studies with objective validated outcome assessments are required to examine interventions to optimize spinal cord perfusion in this setting.

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

Clinical practice guideline development following the GRADE process. 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. 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. 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 90-95mmHg 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 3-7days. 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. 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.

The 2023 AO Spine-Praxis Guidelines in Acute Spinal Cord Injury: What Have We Learned? What Are the Critical Knowledge Gaps and Barriers to Implementation?

Narrative summary of the 2023 AO Spine-Praxis clinical practice guidelines for management in acute spinal cord injury (SCI). The objective of this article is to summarize the key findings of the clinical practice guidelines for the optimal management of traumatic and intraoperative SCI (ISCI). This article will also highlight potential knowledge translation opportunities for each recommendation and discuss important knowledge gaps and areas of future research. Systematic reviews were conducted according to accepted methodological standards to evaluate the current body of evidence and inform the guideline development process. The summarized evidence was reviewed by a multidisciplinary guidelines development group that consisted of international multidisciplinary stakeholders. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of the evidence for each critical outcome and the "evidence to recommendation" framework was used to formulate the final recommendations. The key recommendations regarding the timing of surgical decompression, hemodynamic management, and the prevention, diagnosis, and management of ISCI are summarized. While a strong recommendation was made for early surgery, further prospective research is required to define what constitutes sufficient surgical decompression, examine the role of ultra-early surgery, and assess the impact of early surgery in different SCI phenotypes, including central cord syndrome. Furthermore, additional investigation is required to evaluate the impact of mean arterial blood pressure targets on neurological recovery and to determine the utility of spinal cord perfusion pressure measurements. Finally, there is a need to examine the role of neuroprotective agents for the treatment of ISCI and to prospectively validate the new AO Spine-Praxis care pathway for the prevention, diagnosis, and management of ISCI. To optimize the translation of these guidelines into practice, important barriers to their implementation, particularly in underserved areas, need to be explored. Ultimately, these recommendations will help to establish more personalized approaches to care for SCI patients. The recommendations from the 2023 AO Spine-Praxis guidelines not only highlight the current best practice in the management of SCI, but reveal critical knowledge gaps and barriers to implementation that will help to guide further research efforts in SCI.

Cervical spinal cord angiography and vessel-selective perfusion imaging in the rat.

Arterial spin labeling (ASL) has been widely used to evaluate arterial blood and perfusion dynamics, particularly in the brain, but its application to the spinal cord has been limited. The purpose of this study was to optimize vessel-selective pseudocontinuous arterial spin labeling (pCASL) for angiographic and perfusion imaging of the rat cervical spinal cord. A pCASL preparation module was combined with a train of gradient echoes for dynamic angiography. The effects of the echo train flip angle, label duration, and a Cartesian or radial readout were compared to examine their effects on visualizing the segmental arteries and anterior spinal artery (ASA) that supply the spinal cord. Lastly, vessel-selective encoding with either vessel-encoded pCASL (VE-pCASL) or super-selective pCASL (SS-pCASL) were compared. Vascular territory maps were obtained with VE-pCASL perfusion imaging of the spinal cord, and the interanimal variability was evaluated. The results demonstrated that longer label durations (200 ms) resulted in greater signal-to-noise ratio in the vertebral arteries, improved the conspicuity of the ASA, and produced better quality maps of blood arrival times. Cartesian and radial readouts demonstrated similar image quality. Both VE-pCASL and SS-pCASL adequately labeled the right or left vertebral arteries, which revealed the interanimal variability in the segmental artery with variations in their location, number, and laterality. VE-pCASL also demonstrated unique interanimal variations in spinal cord perfusion with a right-sided dominance across the six animals. Vessel-selective pCASL successfully achieved visualization of the arterial inflow dynamics and corresponding perfusion territories of the spinal cord. These methodological developments provide unique insights into the interanimal variations in the arterial anatomy and dynamics of spinal cord perfusion.

Adherence to international guidelines in neurocritical care of cervical traumatic spinal cord injury-a retrospective study

IntroductionThe American Association of Neurologic Surgeons guidelines on the management of traumatic spinal cord injury (SCI), updated in 2013, focus on spinal cord perfusion, early decompressive surgery, and venous thromboembolism (VTE) prophylaxis to improve neurological outcome. Research questionHow neurocritical care and initial management have changed with the implementation of updated management guidelines, focusing on guidelines adherence and neurological outcome. Material and methodsSystemic physiological variables, time to neurosurgical treatment and VTE prophylaxis, and neurological outcome, were retrospectively collected from adult patients treated for cervical SCI 2001–2021. ResultsFifty-two patients were included. Mean arterial blood pressure (MAP) was significantly higher after 2013 (86±9.9 mmHg) when compared to before 2013 (79±9.9 mmHg), p = 0.041. Median time to surgery was 41 h before, and 20 h after 2013 (p = 0.029). Time to VTE prophylaxis was six days before and four days after 2013. Most neurocritical care complications were less commonly observed after 2013. Despite improved adherence to treatment goals, 44 % of MAP levels were below target, and 33% of patients were operated beyond 24h post-injury. Neurological outcome was not improved after implementation of the revised guidelines. Discussion and conclusionWhile implementation of the revised 2013 guidelines improved most aspects of the acute SCI management, many guideline targets were not met in a large subset of patients. Strict adherence to the acute neurocritical management goals, and early surgical treatment, is likely crucial when aiming to improve SCI outcome.

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

IntroductionThere 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 questionIs 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 methodsA 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. ResultsIn 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 conclusionsThis 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.

The Other Aortic Syndrome-Intramural Hematoma and Neurological Deficit: Case Report.

Acute thoracic aortic syndromes are among the most concerning presentations in emergency medicine and are associated with significant morbidity and mortality. Thoracic aortic dissection is most common, followed by penetrating aortic ulcer and, least commonly, intramural hematoma. A 67-year-old woman presented to the emergency department with chest and back pain, and sudden onset of paraparesis. Aortic intramural hematoma was diagnosed, and she underwent spinal drain placement with blood pressure control to optimize spinal cord perfusion. When neurological deficits are present, rapid diagnosis of spinal ischemia and blood pressure optimization is vital. Spinal drains may be considered as an adjunctive treatment.

Efficacy of levosimendan vs its combination with magnesium sulphate on spinal cord protection in infants undergoing coarctectomy: A randomized controlled study

ABSTRACT Background and Objective Spinal cord ischemia with subsequent paraplegia secondary to aortic coarctation repair procedures is rare, but it has serious consequences that can affect quality of life. Infrared spectroscopy (NIRS) is used for non invasive spinal cord oxygenation monitoring to estimate cord perfusion and detect early cord ischemic changes. Several pharmacological agents have been used to improve cord perfusion, the main action of these agents is to improve regional/systemic perfusion and decrease ICP. In the current study, we studied magnesium sulphate and levosimendan for their vasodilating effect that might improve spinal cord perfusion as part of spinal cord protection. Methods Forty two infants undergoing aortic coarctectomy under general anaesthesia were registered in double blinded randomized controlled study, three groups were included; group C received i.v. saline, group L received levosimendan in loading dose 6ug/kg i.v. for 15 minutes then maintenance dose 0.1 ug/kg/min till end of surgery and group M received levosimendan in loading dose 6 ug/kg i.v. for 15 minutes then maintenance dose 0.1 ug/kg/min in combination with magnesium sulphate in loading dose 25 mg/kg i.v. for 15 minutes then maintenance dose 10 mg/kg/hr till the end of surgery. The vital signs and NIRS values assessed before, during and after clamping of aorta. Results All baseline demographic data were comparable among all groups except for height (cm), which was significantly lower in Group L compared to Group C (p = 0.013). NIRS values were comparable among the three groups throughout experimental protocol except after cross clamp at 20 minutes, where Group M was significantly higher compared to group C (P = 0.007).Heart rate, mean arterial blood pressure, total fluid intake, urine output, aortic cross clamp time and surgical time was comparable among all groups, were comparable among 3 studied groups. Conclusion Adding magnesium sulphate to levosimendan has showed improvement in spinal cord perfusion during cross clamping as monitored by NIRS when compared to use of levosimendan alone or placebo in coarctectomy operations without affecting hemodynamics.