MRI in acute and subacute post-traumatic spinal cord injury: pictorial review

Midsagittal Tissue Bridges as Predictors of Neurological Recovery in Traumatic Cervical Spinal Cord Injury

OBJECTIVE

This study aimed to explore the relationship between intramedullary injury and midsagittal tissue bridges at the epicenter of subacute traumatic cervical spinal cord injury (SCI) and long-term clinical recovery.

METHODS

Imaging and clinical data from 57 traumatic cervical SCI patients at the First Affiliated Hospital of Nanchang University were retrospectively assessed. Midsagittal T2-weighted scans at 1 month postinjury were used to quantify lesion size and tissue bridge width. Correlation analyses were performed to determine the association among tissue bridge width, lesion size, and long-term clinical recovery.

RESULTS

At 1 month after SCI, ventral midsagittal tissue bridges (VMTB), dorsal midsagittal tissue bridges (DMTB), and total midsagittal tissue bridges (TMTB) were associated with better American spinal injury association Impairment Scale grades at 1 year postinjury. Shorter intramedullary lesion length (IMLL) and smaller intramedullary lesion width (IMLW) were linked to better outcomes. TMTB exhibited a stronger correlation with improved American spinal injury association Impairment Scale grades compared to VMTB, DMTB, IMLL, and IMLW. Moreover, IMLL and IMLW were significantly higher, while the DMTB, VMTB, and TMTB widths were significantly lower in patients with a poor prognosis than in those with a good prognosis. Receiver operating characteristic analysis showed TMTB had better predictive performance than other measures.

CONCLUSIONS

The observed association between clinical prognosis and midsagittal tissue bridges underscores the clinical relevance of these structures as neuroimaging biomarkers in patients with subacute SCI. Thus, midsagittal tissue bridges may serve as promising and reliable magnetic resonance imaging biomarkers during the transition from acute to chronic phase for stratifying, treating, and evaluating patient subgroups in clinical trials.

Should dry spinal tuberculosis be managed differently than wet spinal tuberculosis?

BACKGROUND CONTEXT

On radiopathological examination of spinal tuberculosis (TB), 2 predominant forms are known: dry and wet types. Wet TB, as the name suggests, has abscess formation as its predominant presenting feature and is the exudative form; dry TB includes caseation and sequestration with minimal exudate. Dry TB often exhibits poorer recovery patterns than the wet counterparts, which can be possibly ascribed to vasculitis, ischemia, or tubercular myelitis, rather than isolated mechanical compression. These pathologic processes may lead to neurological deficit which is less responsive to treatment.

PURPOSE

To quantify the recovery and prognosis, and test for the significance of difference between neurological recovery pattern and prognosis of the 2 forms of spinal TB.

DESIGN

A retrospective analytical observational study design in the form of a cohort study was performed.

PATIENT SAMPLE

Single-center patient data over 6 years was analyzed. Of 217 patients with spinal TB, 18 had dry TB (Group 1). Two patients were excluded because they presented very late after the onset of neurological deficit, which could have played a role in the nonrecovering nature of motor weakness. The remaining patients had wet TB, of which 22 patients were selected for propensity score matching to form a comparison group.

OUTCOME MEASURES

Radiological measures included vertebral body height loss, deformity, canal encroachment, cord diameter, altered cord signal intensity and loss of CSF space. Functional measures were ambulatory status of the patient at final follow-up and neurologic status measured by ASIA (American Spinal Injury Association) and LEMS (Lower Extremity Motor Score) scoring.

METHODS

The criteria for dry TB were imaging suggestive of granulation tissue (heterogenous hypo- or hyper-intensity on T2WI sequence), with at least 1 of the 2 factors (1) absence of anterior or posterior epidural abscess formation within the spinal canal (2) a canal encroachment of <30%. The groups were compared with respect to their differences in demographic distribution, symptom complex, mycobacterial drug sensitivity and presence of history of tuberculosis elsewhere in the body. Analysis was done by various tests of significance depending on the type of variable. Bar charts and Pie charts were used for visual representation of the analyzed data. Level of significance was set at 0.05.

RESULTS

Dry TB showed partial or no return to ambulation (75% vs. 31.5% in wet, p=.01) at 12-months and took more time to reach final ambulatory level (9.16 months vs. 2.9 months in wet), despite having a lower average Cobb angle (16.5 degrees versus 20.95 in wet (p=.132), lower mean canal-encroachment (24.9% vs. 50.09% in wet, p<.01) and preserved posterior-CSF flow as compared to wet TB (p=.02). At final follow-up, 4/16 (25%) of dry and 0% of wet TB were ASIA A, and 9/16 (56.25%) dry and 18/22 (72.7%) of wet TB were ASIA E (p=.04).

CONCLUSION

Dry TB of the spine has poorer functional outcome in terms of time to ambulation and final ambulatory status despite having minimal destruction and abscess formation causing mechanical cord compression.

A deep learning approach for cervical cord injury severity determination through axial and sagittal magnetic resonance imaging segmentation and classification

STUDY DESIGN

Cross-sectional Database Study.

OBJECTIVE

While the American Spinal Injury Association (ASIA) Impairment Scale is the standard for assessing spinal cord injuries (SCI), it has limitations due to subjectivity and impracticality. Advances in machine learning (ML) and image recognition have spurred research into their use for outcome prediction. This study aims to analyze deep learning techniques for identifying and classifying cervical SCI severity from MRI scans.

METHODS

The study included patients with traumatic and nontraumatic cervical SCI admitted from 2019 to 2022. MRI images were labeled by two senior resident physicians. A deep convolutional neural network was trained using axial and sagittal cervical MRI images from the dataset. Model performance was assessed using Dice Score and IoU to measure segmentation accuracy by comparing predicted and ground truth masks. Classification accuracy was evaluated with the F1 Score, balancing false positives and negatives.

RESULT

In the axial spinal cord segmentation, we achieved a Dice score of 0.94 for and IoU score of 0.89. In the sagittal spinal cord segmentation, we obtained Dice score up to 0.9201 and IoU scores up to 0.8541. The model for axial image score classification gave a satisfactory result with an F1 score of 0.72 and AUC of 0.79.

CONCLUSION

Our models successfully identified cervical SCI on T2-weighted MR images with satisfactory performance. Further research is needed to develop more advanced models for predicting patient outcomes in SCI cases.

No impact of anti-inflammatory medication on inflammation-driven recovery following cervical spinal cord injury in rats

Following spinal cord injury (SCI), inflammation is associated with the exacerbation of damage to spinal tissue. Consequently, managing inflammation during the acute and subacute phases is a common target in SCI treatment. However, inflammation may also induce potential benefits, including the stimulation of neuroplasticity and repair. This positive role of inflammation in spinal cord healing and functional recovery is not fully understood. To address this knowledge gap, we examined the effects of two common anti-inflammatory medications, Diphenhydramine and Methylprednisolone, on the efficacy of rehabilitative motor training on recovery from subacute cervical SCI in adult rats. Training depends critically on neuroplasticity thus if inflammation is a key regulator, we propose that anti-inflammatory drugs will reduce subsequent recovery. Both drugs were administered orally over one month, alongside task-specific reaching and grasping training. After treatment, no substantial changes in motor recovery or lesion size between the treated and control groups were observed. Treated animals also did not show any discernible changes in sensory function or anxiety-like behavior. Taken together, our data indicate that the prolonged use of these anti-inflammatory agents at commonly used doses did not profoundly impact recovery following an SCI. Therefore, considering earlier reports of the benefits of pro-inflammatory stimuli on plasticity, further studies in this area are imperative to elucidate the true impact of treating inflammation and its implications for recovery after spinal cord injuries.

A Study of the Role of Magnetic Resonance Imaging in the Evaluation of T2-Weighted Hyperintensities in Spinal Cord in a Tertiary Care Hospital in Central India

Background T2-weighted hyperintensities in the spinal cord are crucial markers for diagnosing a range of spinal cord pathologies. This study explores the prevalence, causes, and implications of these hyperintensities in patients with spinal cord injuries at a tertiary care hospital in Central India. The research aims to assess the utility of MRI in detecting T2-weighted hyperintensities in the spinal cord and to analyze the associated clinical and radiological characteristics. Materials and methods A prospective observational study was conducted involving patients referred to the Department of Radiodiagnosis at Acharya Vinoba Bhave Rural Hospital (AVBRH), Sawangi (Wardha), with suspected or confirmed spinal cord injuries. Advanced MRI techniques, including T2-weighted imaging, were used for the evaluation. The study analyzed demographic data, clinical features, and MRI findings to identify common causes and patterns of T2-weighted hyperintensities. Results The study revealed that T2-weighted hyperintensities were present in 54 (72%) MRI scans of patients with spinal cord pathologies at our tertiary care hospital in Central India. Among these, multiple sclerosis was the most frequent diagnosis, accounting for 27 (35%) cases. Traumatic spinal cord injuries were observed in 25% (n=19) of patients, while transverse myelitis was found in 15 (20%). The remaining 15 (20%) included a variety of other conditions, such as infections and tumors. The extent and distribution of T2-weighted hyperintensities varied significantly among different diagnoses, with multiple sclerosis and transverse myelitis demonstrating a more extensive involvement compared to trauma-related cases. Conclusion MRI is a valuable tool for diagnosing and understanding the underlying causes of spinal cord hyperintensities. The study highlights the need for targeted diagnostic and therapeutic approaches based on MRI findings to improve patient outcomes in spinal cord injuries.

Conversion of T2-Weighted Magnetic Resonance Images of Cervical Spine Trauma to Short T1 Inversion Recovery (STIR) Images by Generative Adversarial Network

INTRODUCTION

The short T1 inversion recovery (STIR) sequence is advantageous for visualizing ligamentous injuries, but the STIR sequence may be missing in some cases. The purpose of this study was to generate synthetic STIR images from MRI T2-weighted images (T2WI) of patients with cervical spine trauma using a generative adversarial network (GAN).  Methods: A total of 969 pairs of T2WI and STIR images were extracted from 79 patients with cervical spine trauma. The synthetic model was trained 100 times, and the performance of the model was evaluated with five-fold cross-validation.  Results: As for quantitative validation, the structural similarity score was 0.519±0.1 and the peak signal-to-noise ratio score was 19.37±1.9 dB. As for qualitative validation, the incorporation of synthetic STIR images generated by a GAN alongside T2WI substantially enhances sensitivity in the detection of interspinous ligament injuries, outperforming assessments reliant solely on T2WI.

CONCLUSION

The GAN model can generate synthetic STIRs from T2 images of cervical spine trauma using image-to-image conversion techniques. The use of a combination of synthetic STIR images generated by a GAN and T2WI improves sensitivity in detecting interspinous ligament injuries compared to assessments that use only T2WI.

Improved Recovery of Complete Spinal Cord Transection by a Plasma-Modified Fibrillar Scaffold

Complete spinal cord injury causes an irreversible disruption in the central nervous system, leading to motor, sensory, and autonomic function loss, and a secondary injury that constitutes a physical barrier preventing tissue repair. Tissue engineering scaffolds are presented as a permissive platform for cell migration and the reconnection of spared tissue. Iodine-doped plasma pyrrole polymer (pPPy-I), a neuroprotective material, was applied to polylactic acid (PLA) fibers and implanted in a rat complete spinal cord transection injury model to evaluate whether the resulting composite implants provided structural and functional recovery, using magnetic resonance (MR) imaging, diffusion tensor imaging and tractography, magnetic resonance spectroscopy, locomotion analysis, histology, and immunofluorescence. In vivo, MR studies evidenced a tissue response to the implant, demonstrating that the fibrillar composite scaffold moderated the structural effects of secondary damage by providing mechanical stability to the lesion core, tissue reconstruction, and significant motor recovery. Histologic analyses demonstrated that the composite scaffold provided a permissive environment for cell attachment and neural tissue guidance over the fibers, reducing cyst formation. These results supply evidence that pPPy-I enhanced the properties of PLA fibrillar scaffolds as a promising treatment for spinal cord injury recovery.

Model-based parcellation of diffusion MRI of injured spinal cord predicts hand use impairment and recovery in squirrel monkeys

A mathematical model-based parcellation of magnetic resonance diffusion tensor images (DTI) has been developed to quantify progressive changes in three types of tissues - grey (GM), white matter (WM), and damaged spinal cord tissue, along with behavioral assessments over a 6 month period following targeted spinal cord injuries (SCI) in monkeys. Sigmoid Gompertz function based fittings of DTI metrics provide early indicators that correlate with, and predict, recovery of hand grasping behavior. Our three tissue pool model provided unbiased, data-driven segmentation of spinal cord images and identified DTI metrics that can serve as reliable biomarkers of severity of spinal cord injuries and predictors of behavioral outcomes.

Integrated Machine Learning Approach for the Early Prediction of Pressure Ulcers in Spinal Cord Injury Patients

(1) Background: Pressure ulcers (PUs) substantially impact the quality of life of spinal cord injury (SCI) patients and require prompt intervention. This study used machine learning (ML) techniques to develop advanced predictive models for the occurrence of PUs in patients with SCI. (2) Methods: By analyzing the medical records of 539 patients with SCI, we observed a 35% incidence of PUs during hospitalization. Our analysis included 139 variables, including baseline characteristics, neurological status (International Standards for Neurological Classification of Spinal Cord Injury [ISNCSCI]), functional ability (Korean version of the Modified Barthel Index [K-MBI] and Functional Independence Measure [FIM]), and laboratory data. We used a variety of ML methods-a graph neural network (GNN), a deep neural network (DNN), a linear support vector machine (SVM_linear), a support vector machine with radial basis function kernel (SVM_RBF), K-nearest neighbors (KNN), a random forest (RF), and logistic regression (LR)-focusing on an integrative analysis of laboratory, neurological, and functional data. (3) Results: The SVM_linear algorithm using these composite data showed superior predictive ability (area under the receiver operating characteristic curve (AUC) = 0.904, accuracy = 0.944), as demonstrated by a 5-fold cross-validation. The critical discriminators of PU development were identified based on limb functional status and laboratory markers of inflammation. External validation highlighted the challenges of model generalization and provided a direction for future research. (4) Conclusions: Our study highlights the importance of a comprehensive, multidimensional data approach for the effective prediction of PUs in patients with SCI, especially in the acute and subacute phases. The proposed ML models show potential for the early detection and prevention of PUs, thus contributing substantially to improving patient care in clinical settings.

Traumatic Spinal Cord Injury

OBJECTIVE

This article provides a review of the initial clinical and radiologic evaluation and treatment of patients with traumatic spinal cord injuries. It specifically highlights essential knowledge for neurologists who encounter patients with these complex injuries.

LATEST DEVELOPMENTS

There has been improvement in the care of patients with traumatic spinal cord injuries, particularly in the prehospital evaluation, approach for immediate immobilization, standardized spinal clearance, efficient triage, and transportation of appropriate patients to traumatic spinal cord injury specialized centers. Advancements in spinal instrumentation have improved the surgical management of spinal fractures and the ability to manage patients with spinal mechanical instability. The clinical evidence favors performing early surgical decompression and spine stabilization within 24 hours of traumatic spinal cord injuries, regardless of the severity or location of the injury. There is no evidence that supports the use of neuroprotective treatments to improve outcomes in patients with traumatic spinal cord injuries. The administration of high-dose methylprednisolone, which is associated with significant systemic adverse effects, is strongly discouraged. Early and delayed mortality rates continue to be high in patients with traumatic spinal cord injuries, and survivors often confront substantial long-term physical and functional impairments. Whereas the exploration of neuroregenerative approaches, such as stem cell transplantation, is underway, these methods remain largely investigational. Further research is still necessary to advance the functional recovery of patients with traumatic spinal cord injuries.

ESSENTIAL POINTS

Traumatic spinal cord injury is a complex and devastating condition that leads to long-term neurologic deficits with profound physical, social, and vocational implications, resulting in a diminished quality of life, particularly for severely affected patients. The initial management of traumatic spinal cord injuries demands comprehensive interdisciplinary care to address the potentially catastrophic multisystem effects. Ongoing endeavors are focused on optimizing and customizing initial management approaches and developing effective therapies for neuroprotection and neuroregeneration to enhance long-term functional recovery.

Cross-hemicord spinal fiber reorganization associates with cortical sensory and motor network expansion in the rat model of hemicontusion cervical spinal cord injury

Magnetic resonance imaging plays an important role in characterizing microstructural changes and reorganization after traumatic injuries to the nervous system. In this study, we tested the feasibility of ex-vivo spinal cord diffusion tensor imaging (DTI) in combination with in vivo brain functional MRI to characterize spinal reorganization and its supraspinal association after a hemicontusion cervical spinal cord injury (SCI). DTI parameters (fractional anisotropy [FA], mean diffusion [MD]) and fiber orientation changes related to reorganization in the contused cervical spinal cord were compared to sham specimens. Altered fiber density and fiber directions occurred across the ipsilateral and contralateral hemicords but with only ipsilateral FA and MD changes. The hemicontusion SCI resulted in ipsilateral fiber breaks, voids and vivid fiber reorientations along the injury epicenter. Fiber directional changes below the injury level were primarily inter-hemispheric, indicating prominent below-level cross-hemispheric reorganization. In vivo resting state functional connectivity of the brain from the respective rats before obtaining the spinal cord samples indicated spatial expansion and increased connectivity strength across both the sensory and motor networks after SCI. The consistency of the neuroplastic changes along the neuraxis (both brain and spinal cord) at the single-subject level, indicates that distinctive reorganizational relationships exist between the spinal cord and the brain post-SCI.

Finite element analysis of electric field distribution during direct current stimulation of the spinal cord: Implications for device design

Spinal cord injury (SCI) arises from damage to the spinal cord, often caused by trauma or disease. The resulting sensorimotor dysfunction is variable and dependent on the extent of the injury. Despite years of research, curative options for SCI remain limited. However, recent advancements in electric field stimulated axonal regrowth have shown promise for neuronal regeneration. One roadblock in the development of therapeutic treatments based on this is a lack of understanding of the exogenous electric field distribution in the injured tissue, and in particular, how this is influenced by electrode geometry and placement. To better understand this electric field, and provide a means by which it can be optimized, we have developed a finite element model of such spinal cord treatment. We investigate the impact of variations in electrode geometry, spinal cord size, and applied current magnitude as well as looking at several injury models in relation to clinically observed outcomes. Through this, we show that electrode shape has little effect on the induced electric field, that the placement of these electrodes has a noticeable influence on the field distribution, and that the magnitude of this field is governed by both the applied current and the spinal cord morphology. We also show that the injury modality influences the induced field distribution and that a stronger understanding of the injury will help decide treatment parameters. This work provides guidance in the design of electrodes for future clinical application in direct current electric field stimulation for axonal regeneration.

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.

Species Differences in Blood Lymphocyte Responses After Spinal Cord Injury

People with spinal cord injury (SCI) get recurrent infections, such as urinary tract infections (UTIs) and pneumonias, that cause mortality and worsen neurological recovery. Over the past decades, researchers have proposed that post-SCI lymphopenia and decreased lymphocyte function increase susceptibility to infections and worsen neurological outcome in humans, leading to a condition called SCI-induced immune depression syndrome (SCI-IDS). In this review, we explore how SCI affects blood lymphocyte homeostasis and function in humans and rodents. Understanding how SCI affects blood lymphocytes will help the management of recurrent infections in spinal cord injured people and shed light on the clinical translation of findings in animal models to humans.

Difficulties capturing co-occurring traumatic brain injury among people with traumatic spinal cord injury: a population-based study

STUDY DESIGN

This is a population-based prospective cohort study.

OBJECTIVES

Traumatic brain injury (TBI) is common among people with traumatic spinal cord injury (TSCI), but rates vary across studies associated with variable approaches to diagnosis. We aimed to determine if a published diagnostic algorithm could be consistently applied to capture co-occurring TBI among persons sustaining TSCI.

SETTING

One of two spinal centres in New Zealand (NZ), the Burwood Spinal Unit (BSU) captures approximately 45% of NZ TSCI admissions.

METHODS

Adults (age 16+) with TSCI admitted to the BSU between 1 January 2021 and 31 August 2021 (n = 51) were included. Clinical notes were audited prospectively to identify co-occurring TBI.

RESULTS

We identified co-occurring TBI in 39% of TSCI cases with a small number of additional suspected TBI cases where TBI could not be confidently ruled in or out. Including all TBI cases, suspected or otherwise resulted in up to 55% of the sample having sustained co-occurring TBI. There were difficulties applying the published algorithm, associated with inconsistent documentation of TBI indicators from acute to rehabilitation contexts.

CONCLUSIONS

In this study, the feasibility of a TBI diagnostic algorithm for the TSCI population was low. Alternative approaches to screening for TBI among people sustaining TSCI are needed. Greater consistency in documenting TBI across the continuum of care will ensure TBI if present, is included in treatment planning.

Acute Magnetic Resonance Imaging Predictors of Chronic Motor Function and Tissue Sparing in Rat Cervical Spinal Cord Injury

Predicting functional outcomes from spinal cord injury (SCI) at the acute setting is important for patient management. This work investigated the relationship of early magnetic resonance imaging (MRI) biomarkers in a rat model of cervical contusion SCI with long-term functional outcome and tissue sparing. Forty rats with contusion injury at C5 at either the spinal cord midline (bilateral) or over the lateral cord (unilateral) were examined using in vivo multi-modal quantitative MRI at 1 day post-injury. The extent of T2-weighted hyperintensity reflecting edema was greater in the bilateral model compared with the unilateral injury. Diffusion tensor imaging (DTI) exhibited microscopic damage in similar regions of the cord as reductions in fractional anisotropy (FA) and mean diffusivity (MD), but DTI parameter maps were also confounded by the presence of vasogenic edema that locally increased FA and MD. In comparison, filtered diffusion-weighted imaging (fDWI) more clearly delineated the location of acute axonal damage without effects of vasogenic edema. Pairwise correlation analysis revealed that 28-day motor functional outcomes were most strongly associated with the extent of edema (R = -0.69). Principal component analysis identified close associations of motor functional score with tissue sparing, the extent of edema, lesion area, and injury type (unilateral or bilateral). Among the diffusion MRI parameters, lesion areas measured with fDWI had the strongest association with functional outcome (R = -0.41). Voxelwise correlation analysis identified a locus of white matter damage associated with function in the dorsal white matter, although this was likely driven by variance across the two injury patterns (unilateral and bilateral injury). Nonetheless, correlation with motor function within the damaged region found in the voxelwise analysis outperformed morphological lesion area measurement as a predictor of chronic function. Collectively, this study characterized anatomical and diffusion MRI signatures of acute SCI at cervical spine and their association with chronic functional outcomes and histological results.

Quantifying Intraparenchymal Hemorrhage after Traumatic Spinal Cord Injury: A Review of Methodology

Intraparenchymal hemorrhage (IPH) after a traumatic injury has been associated with poor neurological outcomes. Although IPH may result from the initial mechanical trauma, the blood and its breakdown products have potentially deleterious effects. Further, the degree of IPH has been correlated with injury severity and the extent of subsequent recovery. Therefore, accurate evaluation and quantification of IPH following traumatic spinal cord injury (SCI) is important to define treatments' effects on IPH progression and secondary neuronal injury. Imaging modalities, such as magnetic resonance imaging (MRI) and ultrasound (US), have been explored by researchers for the detection and quantification of IPH following SCI. Both quantitative and semiquantitative MRI and US measurements have been applied to objectively assess IPH following SCI, but the optimal methods for doing so are not well established. Studies in animal SCI models (rodent and porcine) have explored US and histological techniques in evaluating SCI and have demonstrated the potential to detect and quantify IPH. Newer techniques using machine learning algorithms (such as convolutional neural networks [CNN]) have also been studied to calculate IPH volume and have yielded promising results. Despite long-standing recognition of the potential pathological significance of IPH within the spinal cord, quantifying IPH with MRI or US is a relatively new area of research. Further studies are warranted to investigate their potential use. Here, we review the different and emerging quantitative MRI, US, and histological approaches used to detect and quantify IPH following SCI.

Differences between spinal cord injury and cervical compressive myelopathy in intramedullary high-intensity lesions on T2-weighted magnetic resonance imaging: A retrospective study

Increases in aging populations have raised the number of patients with cervical spinal cord injury (SCI) without fractures due to compression of the cervical spinal cord. In such patients, it is necessary to clarify whether SCI or cervical compressive myelopathy (CCM) is the cause of disability after trauma. This study aimed to clarify the differences in magnetic resonance imaging (MRI) features between SCI and CCM. Overall, 60 SCI patients and 60 CCM patients with intramedullary high-intensity lesions on T2-weighted MRI were included in this study. The longitudinal lengths of the intramedullary T2 high-intensity lesions were measured using sagittal MRI sections. Snake-eye appearance on axial sections was assessed as a characteristic finding of CCM. The T2 values of the high-intensity lesions and normal spinal cords at the first thoracic vertebra level were measured, and the contrast ratio was calculated using these values. The longitudinal length of T2 high-intensity lesions was significantly longer in SCI patients than in CCM patients. Snake-eye appearance was found in 26 of the 60 CCM patients, but not in SCI patients. On both the sagittal and axial images, the contrast ratio was significantly higher in the SCI group than in the CCM group. Based on these results, a diagnostic scale was created. This scale made it possible to distinguish between SCI and CCM with approximately 90% accuracy.

Neuroplasticity of spinal cord injury and repair

The sudden loss of movement after spinal cord injury (SCI) is life-changing and is a major impetus to study spinal cord motor system plasticity and devise novel repair strategies. This review focuses on the motor cortex and the corticospinal tract, which are key to producing voluntary movements. The motor cortex projects directly to the spinal cord, via the corticospinal tract, and indirectly, via relays in the brain stem. With loss of the corticospinal tract after SCI, the indirect paths may bypass the injury and play an important role in voluntary control. In health and after injury, the spinal cord is a key site for activity-dependent neuroplasticity of the corticospinal system. Three kinds of activity-dependent plasticity have been identified: (1) corticospinal tract axon sprouting after electrical stimulation of the motor cortex; (2) synaptic competition between corticospinal tract and proprioceptive afferent fiber terminations; and (3) long-term potentiation (LTP) at the corticospinal tract-spinal interneuron synapse. SCI damages descending motor pathway connections and, in turn, triggers a loss of down-stream activity-dependent processes. This activity loss produces spinal interneuron degeneration and several activity-dependent maladaptive changes that underly hyperreflexia, spasticity, and spasms. Animal studies show that phasic electrical and tonic direct current stimulation can be used to supplement activity after SCI to reduce the activity-dependent degenerative and maladaptive changes. Importantly, when applied chronically neuromodulation recruits spinal neuroplasticity to improve function after SCI by promoting activity-dependent corticospinal axon sprouting and synapse formation. This helps establish new functional connections and strengthens spared connections. Combining neuromodulation to promote repair and motor rehabilitation to train circuits can most effectively promote motor recovery.

Spine MRI: A Review of Commonly Encountered Emergent Conditions

Over the last 2 decades, the proliferation of magnetic resonance imaging (MRI) availability and continuous improvements in acquisition speeds have led to significantly increased MRI utilization across the health care system, and MRI studies are increasingly ordered in the emergent setting. Depending on the clinical presentation, MRI can yield vital diagnostic information not detectable with other imaging modalities. The aim of this text is to report on the up-to-date indications for MRI of the spine in the ED, and review the various MRI appearances of commonly encountered acute spine pathology, including traumatic injuries, acute non traumatic myelopathy, infection, neoplasia, degenerative disc disease, and postoperative complications. Imaging review will focus on the aspects of the disease process that are not readily resolved with other modalities.

Early Management of Spinal Cord Injury: WFNS Spine Committee Recommendations

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

Prevalence of sports-related spinal injury stratified by competition level and return to play guidelines

Spinal injury is among the most severe and feared injuries an athlete may face. We present an up-to-date review of the recent literature, stratifying recommendations based on injury location (cervical, thoracic, and lumbar spine) and type, as well as, the level of competitive play (high school, collegiate, professional). A literature search was completed to identify all publications reporting return to play guidelines for athletic injuries or injury-related surgery irrespective of the study design. Publication dates were not restricted by year. Search terms used included "return to play" and "spinal injury" on National Library of Medicine (PubMed) and Google Scholar. Selection criteria for literature included axial spine injury guidelines for athletic participation post-injury or post-surgery. Literature found from the search criteria was sorted based on level of competition and location of axial spine injury involved. It was found that professional athletes are more likely to suffer severe spinal injuries, require surgery, and necessitate a longer return to play (RTP), with high school and college athletes usually returning to play within days or weeks. Injuries occur mainly within contact sports and concordance exists between initial and subsequent spinal injuries. Adequate rest, rehabilitation, and protective equipment alongside the education of athletes and coaches are recommended. In conclusion, a multidisciplinary approach to patient management is required with consideration for the emotional, social, and perhaps financial impact that spinal injury may have upon the athlete. Consensus from the literature states that in order for an athlete to safely return to play, that athlete should not be actively suffering from pain, should have a full range of motion, and complete return of their strength in the absence of neurological deficit.

Pharmacokinetics and anti-inflammatory effect of naproxen in rats with acute and subacute spinal cord injury

Previous reports have warned about the influence of spinal cord injury (SCI) on the pharmacokinetics of various drugs. However, the role of SCI in the efficacy and safety of pharmacotherapy remains unknown. Thereby, our aim was to explore the role of SCI on pharmacokinetics and anti-inflammatory effect of naproxen in response to a local inflammatory challenge. Rats received a severe contusive SCI at T9 or sham injury. Pharmacokinetics of a single intravenous dose of naproxen (10 mg kg^-1) was studied at days 1 and 15 post-surgery. For the anti-inflammatory assessment, carrageenan was subcutaneously injected in forelimb and hindlimb paws at the same post-surgery periods, and naproxen efficacy was evaluated measuring paw swelling. Plasma protein concentrations and body weight changes were also determined. Plasma naproxen levels and pharmacokinetic parameters were unchanged by acute injury, but subacute injury generated alterations in volume of distribution, clearance, and bioavailability, resulting in significantly reduced plasma naproxen concentrations, in the absence of changes in plasma proteins. Assessment of naproxen anti-inflammatory activity during the acute stage of injury could not be determined because of carrageenan failure to elicit swelling. During the subacute stage, naproxen anti-inflammatory effect on forelimbs (above injury) was similar to that observed in sham-injured animals, while it was almost absent in paralyzed hindlimbs. Under conditions of SCI and peripheral inflammation, pharmacokinetics and anti-inflammatory activity of naproxen vary according to post-injury timing and neurological status of the assessed region.

Traumatic Spinal Cord Injury

PURPOSE OF REVIEW

This article provides an update on the acute and subacute management and prognostication of patients with traumatic spinal cord injury.

RECENT FINDINGS

Immobilization of the spine and spine clearance should be individualized depending on the ability to perform a reliable neurologic examination, the presence of neck pain, and the imaging findings. Early surgery (within 24 hours) to achieve definitive cord decompression and spine stabilization may be beneficial. Ensuring adequate oxygenation and perfusion and avoiding secondary systemic complications remain the goals of the critical care of these patients. No neuroprotective treatment has been shown to improve outcomes. In fact, the use of high-dose methylprednisolone is now generally discouraged because of its major systemic adverse effects. Survivors of severe cervical traumatic spinal cord injury typically sustain substantial long-term functional impairment. Advances in our understanding of neuroregenerative strategies, especially stem cell transplantation, can offer the future hope of functional improvement to the many patients currently living with the consequences of traumatic spinal cord injury. Yet, at present, these therapies remain strictly investigational.

SUMMARY

The treatment of traumatic spinal cord injury remains supportive, and prognosis is still poor for patients who are severely affected. While much remains to be learned about how to optimize the acute management of these patients, future efforts would be most useful if focused on injury prevention and the development of effective neuroregenerative therapies.

Traumatic cervical spinal cord transection

MRI plays a crucial role in the assessment of spinal cord injury in cervical trauma. Transection of the cord is a rare post-traumatic cord injury, which appears on T₂W images as a high signal between the two disrupted ends of the cord.

Width and neurophysiologic properties of tissue bridges predict recovery after cervical injury

OBJECTIVE

To assess whether preserved dorsal and ventral midsagittal tissue bridges after traumatic cervical spinal cord injury (SCI) encode tract-specific electrophysiologic properties and are predictive of appropriate recovery.

METHODS

In this longitudinal study, we retrospectively assessed MRI scans at 1 month after SCI that provided data on width and location (dorsal vs ventral) of midsagittal tissue bridges in 28 tetraplegic patients. Regression analysis assessed associations between midsagittal tissue bridges and motor- and sensory-specific electrophysiologic recordings and appropriate outcome measures at 12 months after SCI.

RESULTS

Greater width of dorsal midsagittal tissue bridges at 1 month after SCI identified patients who were classified as being sensory incomplete at 12 months after SCI (p = 0.025), had shorter sensory evoked potential (SEP) latencies (r = -0.57, p = 0.016), and had greater SEP amplitudes (r = 0.61, p = 0.001). Greater width of dorsal tissue bridges predicted better light-touch score at 12 months (r = 0.40, p = 0.045) independently of baseline clinical score and ventral tissue bridges. Greater width of ventral midsagittal tissue bridges at 1 month identified patients who were classified as being motor incomplete at 12 months (p = 0.002), revealed shorter motor evoked potential (MEP) latencies (r = -0.54, p = 0.044), and had greater ratios of MEP amplitude to compound muscle action potential amplitude (r = 0.56, p = 0.005). Greater width of ventral tissue bridges predicted better lower extremity motor scores at 12 months (r = 0.41, p = 0.035) independently of baseline clinical score and dorsal tissue bridges.

CONCLUSION

Midsagittal tissue bridges, detectable early after SCI, underwrite tract-specific electrophysiologic communication and are predictors of appropriate sensorimotor recovery. Neuroimaging biomarkers of midsagittal tissue bridges may be integrated into the diagnostic workup, prediction of recovery, and patients' stratification in clinical trials.

Highlighting discrepancies in walking prediction accuracy for patients with traumatic spinal cord injury: an evaluation of validated prediction models using a Canadian Multicenter Spinal Cord Injury Registry

BACKGROUND CONTEXT

Models for predicting recovery in traumatic spinal cord injury (tSCI) patients have been developed to optimize care. Several models predicting tSCI recovery have been previously validated, yet recent findings question their accuracy, particularly in patients whose prognoses are the least predictable.

PURPOSE

To compare independent ambulatory outcomes in AIS (ASIA [American Spinal Injury Association] Impairment Scale) A, B, C, and D patients, as well as in AIS B+C and AIS A+D patients by applying two existing logistic regression prediction models.

STUDY DESIGN

A prospective cohort study.

PARTICIPANT SAMPLE

Individuals with tSCI enrolled in the pan-Canadian Rick Hansen SCI Registry (RHSCIR) between 2004 and 2016 with complete neurologic examination and Functional Independence Measure (FIM) outcome data.

OUTCOME MEASURES

The FIM locomotor score was used to assess independent walking ability at 1-year follow-up.

METHODS

Two validated prediction models were evaluated for their ability to predict walking 1-year postinjury. Relative prognostic performance was compared with the area under the receiver operating curve (AUC).

RESULTS

In total, 675 tSCI patients were identified for analysis. In model 1, predictive accuracies for 675 AIS A, B, C, and D patients as measured by AUC were 0.730 (95% confidence interval [CI] 0.622-0.838), 0.691 (0.533-0.849), 0.850 (0.771-0.928), and 0.516 (0.320-0.711), respectively. In 160 AIS B+C patients, model 1 generated an AUC of 0.833 (95% CI 0.771-0.895), whereas model 2 generated an AUC of 0.821 (95% CI 0.754-0.887). The AUC for 515 AIS A+D patients was 0.954 (95% CI 0.933-0.975) with model 1 and 0.950 (0.928-0.971) with model 2. The difference in prediction accuracy between the AIS B+C cohort and the AIS A+D cohort was statistically significant using both models (p=.00034; p=.00038). The models were not statistically different in individual or subgroup analyses.

CONCLUSIONS

Previously tested prediction models demonstrated a lower predictive accuracy for AIS B+C than AIS A+D patients. These models were unable to effectively prognosticate AIS A+D patients separately; a failure that was masked when amalgamating the two patient populations. This suggests that former prediction models achieved strong prognostic accuracy by combining AIS classifications coupled with a disproportionately high proportion of AIS A+D patients.

A practical approach to the diagnosis of spinal cord lesions

Every neurologist will be familiar with the patient with atypical spinal cord disease and the challenges of taking the diagnosis forward. This is predominantly because of the limited range of possible clinical and investigation findings making most individual features non-specific. The difficulty in obtaining a tissue diagnosis further contributes and patients are often treated empirically based on local prevalence and potential for reversibility. This article focuses on improving the diagnosis of adult non-traumatic, non-compressive spinal cord disorders. It is structured to start with the clinical presentation in order to be of practical use to the clinician. We aim, by combining the onset phenotype with the subsequent course, along with imaging and laboratory features, to improve the diagnostic process.

A prospective study of neurological outcome in relation to findings of imaging modalities in acute spinal cord injury

AIM

The aim was to correlate the clinical profile and neurological outcome with findings of imaging modalities in acute spinal cord injury (SCI) patients.

SUBJECTS AND METHODS

Imaging (radiographs, computed tomography [CT], and magnetic resonance imaging [MRI]) features of 25 patients of acute SCI were analyzed prospectively and correlated with clinical and neurology outcome at presentation, 3, 6 and 12 months.

RESULTS

Average initial sagittal index, Gardner's index, and regional kyphosis were 8.12 ± 3.90, 15.68 ± 4.09, 16.44 ± 2.53, respectively; and at 1-year were 4.8 ± 3.03, 12.24 ± 4.36, 12.44 ± 2.26, respectively. At presentation patients with complete SCI had significantly more compression percentage (CP) (P < 0.001), maximum canal compromise (P < 0.001), maximum spinal cord compression (P < 0.001), in comparison to incomplete SCI patients. Qualitative MRI findings; hemorrhage, cord swelling, stenosis showed a predilection toward complete SCI. Improvement in canal dimensions (P = 0.001), beck index (P = 0.008), spinal cord edema (P = 0.010) and stenosis (P = 0.001) was more significant in patients managed operatively; but it was not associated with improved neurological outcome. Cord edema was found more in incomplete SCI patients. Patients presenting with complete SCI improved neurologically to a lesser extent.

CONCLUSIONS

The present study concludes that imaging modalities in spinal cord injuries have a major role in diagnosis, directing management and predicting prognosis. Imaging findings of severe kyphotic deformities, higher canal and cord compression, lesion length, hemorrhage, and cord swelling are associated with poor initial neurological status and recovery. Quantitative and qualitative parameters measured on MRI have a significant role in predicting initial severity of neurological status and outcome. Operative intervention helps in improving few of these imaging parameters, but not ultimate neurological outcome. MRI is an excellent modality to evaluate acute SCI, and MR images obtained in the acute period significantly and usefully predict neurological outcome.

Evaluation of Traumatic Spine by Magnetic Resonance Imaging and Correlation with Neurological Recovery

Study Design

Prospective study.

Purpose

To compare magnetic resonance imaging (MRI) findings with clinical profile and neurological status of the patient and to correlate the MRI findings with neurological recovery of the patients and predict the outcome.

Overview of Literature

Previous studies have reported poor neurological recovery in patients with cord hemorrhage, as compared to cord edema in spine injury patients. High canal compromise, cord compression along with higher extent of cord injury also carries poor prognostic value.

Methods

Neurological status of patients was assessed at the time of admission and discharge in as accordance with the American Spine Injury Association (ASIA) impairment scale. Mean stay in hospital was 14.11±5.74 days. Neurological status at admission and neurological recovery at discharge was compared with various qualitative cord findings and quantitative parameters on MRI. In 27 patients, long-term follow-up was done at mean time of 285.9±43.94 days comparing same parameters.

Results

Cord edema and normal cord was associated with favorable neurological outcome. Cord contusion showed lesser neurological recovery, as compared to cord edema. Cord hemorrhage was associated with worst neurological status at admission and poor neurological recovery. Mean canal compromise (MCC), mean spinal cord compression (MSCC) and lesion length values were higher in patients presenting with ASIA A impairment scale injury and showed decreasing trends towards ASIA E impairment scale injury. Patients showing neurological recovery had lower mean MCC, MSCC, and lesion length, as compared to patients showing no neurological recovery (p<0.05).

Conclusions

Cord hemorrhage, higher MCC, MSCC, and lesion length values have poor prognostic value in spine injury patients.

Clinical applicability of magnetic resonance imaging in acute spinal cord trauma

PURPOSE

To assess the clinical application of magnetic resonance imaging (MRI) in patients with acute spinal cord trauma (SCT) according to the type, extension, and severity of injury and the clinical-radiological correlation.

METHODS

Diagnostic imaging [computed tomography (CT) and MRI] tests of 98 patients with acute SCT were analyzed to assess their clinical diagnostic value. The following radiological findings of SCT were investigated: vertebral compression fractures, bursts and dislocations, posterior element fractures, C1 and C2 lesions, vertebral listhesis, bone swelling, spinal canal compression, disk herniation, extradural hematoma, spinal cord contusions, spinal cord swelling, and posterior ligamentous complex (PLC) injuries.

RESULTS

The radiological findings were better visualized using MRI, except for the posterior elements (p = 0.001), which were better identified with CT. A total of 271 lesions were diagnosed as follows: 217 using MRI, 154 using CT, and 100 (36.9 %) using both MRI and CT. MRI detected 117 more lesions than CT.

CONCLUSION

MRI was significantly superior to CT in the diagnosis of bone swelling, PLC injury, disk herniation, spinal canal compression, spinal cord contusion and swelling present in SCT. MRI detected a larger number of lesions than CT and is highly useful for the diagnosis of soft tissue and intrathecal injuries.