Traumatic and non-traumatic spinal cord-injured patients in Quebec, Canada. Part 2: biochemical profile

Regulating Astrocytes via Short Fibers for Spinal Cord Repair

Reactive astrogliosis is the main cause of secondary injury to the central nerves. Biomaterials can effectively suppress astrocyte activation, but the mechanism remains unclear. Herein, Differentially Expressed Genes (DEGs) are identified through whole transcriptome sequencing in a mouse model of spinal cord injury, revealing the VIM gene as a pivotal regulator in the reactive astrocytes. Moreover, DEGs are predominantly concentrated in the extracellular matrix (ECM). Based on these, 3D injectable electrospun short fibers are constructed to inhibit reactive astrogliosis. Histological staining and functional analysis indicated that fibers with unique 3D network spatial structures can effectively constrain the reactive astrocytes. RNA sequencing and single-cell sequencing results reveal that short fibers downregulate the expression of the VIM gene in astrocytes by modulating the "ECM receptor interaction" pathway, inhibiting the transcription of downstream Vimentin protein, and thereby effectively suppressing reactive astrogliosis. Additionally, fibers block the binding of Vimentin protein with inflammation-related proteins, downregulate the NF-κB signaling pathway, inhibit neuron apoptosis, and consequently promote the recovery of spinal cord neural function. Through mechanism elucidation-material design-feedback regulation, this study provides a detailed analysis of the mechanism chain by which short fibers constrain the abnormal spatial expansion of astrocytes and promote spinal cord neural function.

Spinal Obstruction-Related vs. Craniocervical Junction-Related Syringomyelia: A Comparative Study

Background

No prior reports have focused on spinal cord injury (SCI) characteristics or inflammation after destruction of the blood–spinal cord barrier by syringomyelia. This study aimed to determine the differences in syringomyelia-related central SCI between craniocervical junction (CCJ) syringomyelia and post-traumatic syringomyelia (PTS) before and after decompression.

Methods

In all, 106 CCJ, 26 CCJ revision and 15 PTS patients (mean history of symptoms, 71.5 ± 94.3, 88.9 ± 85.5, and 32.3 ± 48.9 months) between 2015 and 2019 were included. The symptom course was analyzed with the American Spinal Injury Association ASIA and Klekamp–Samii scoring systems, and neurological changes were analyzed by the Kaplan–Meier statistics. The mean follow-up was 20.7 ± 6.2, 21.7 ± 8.8, and 34.8 ± 19.4 months.

Results

The interval after injury was longer in the PTS group, but the natural history of syringomyelia was shorter (p = 0.0004 and 0.0173, respectively). The initial symptom was usually paraesthesia (p = 0.258), and the other main symptoms were hypoesthesia (p = 0.006) and abnormal muscle strength (p = 0.004), gait (p < 0.0001), and urination (p < 0.0001). SCI associated with PTS was more severe than that associated with the CCJ (p = 0.003). The cavities in the PTS group were primarily located at the thoracolumbar level, while those in the CCJ group were located at the cervical-thoracic segment at the CCJ. The syrinx/cord ratio of the PTS group was more than 75% (p = 0.009), and the intradural adhesions tended to be more severe (p < 0.0001). However, there were no significant differences in long-term clinical efficacy or peripheral blood inflammation markers (PBIMs) except for the red blood cell (RBC) count (p = 0.042).

Conclusion

PTS tends to progress faster than CCJ-related syringomyelia. Except for the RBC count, PBIMs showed no value in distinguishing the two forms of syringomyelia. The predictive value of the neutrophil-to-lymphocyte ratio for syringomyelia-related inflammation was negative except in the acute phase.

A Preliminary Cohort Study Assessing Routine Blood Analyte Levels and Neurological Outcome after Spinal Cord Injury

There is increasing interest in the identification of biomarkers that could predict neurological outcome following a spinal cord injury (SCI). Although initial American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade is a good indicator of neurological outcome, for the patient and clinicians, an element of uncertainty remains. This preliminary study aimed to assess the additive potential of routine blood analytes following principal component analysis (PCA) to develop prognostic models for neurological outcome following SCI. Routine blood and clinical data were collected from SCI patients (n = 82) and PCA used to reduce the number of blood analytes into related factors. Outcome neurology was obtained from AIS scores at 3 and 12 months post-injury, with motor (AIS and total including all myotomes) and sensory (AIS, touch and pain) abilities being assessed individually. Multiple regression models were created for all outcome measures. Blood analytes relating to “liver function” and “acute inflammation and liver function” factors were found to significantly increase prediction of neurological outcome at both 3 months (touch, pain, and AIS sensory) and at 1 year (pain, R² increased by 0.025 and total motor, R² increased by 0.016). For some models “liver function” and “acute inflammation and liver function” factors were both significantly predictive, with the greatest combined R² improvement of 0.043 occurring for 3 month pain prediction. These preliminary findings support ongoing research into the use of routine blood analytes in the prediction of neurological outcome in SCI patients.

Vitamin D and spinal cord injury: should we care?

STUDY DESIGN

Narrative review.

OBJECTIVES

This review provides an overview of the etiological factors and consequences of vitamin D insufficiency in relation to spinal cord injury (SCI) as well as important considerations for vitamin D supplementation.

SETTING

Montreal, Canada.

METHODS

Literature search.

RESULTS

Vitamin D insufficiency is common in SCI individuals owing to the presence of many contributing factors including limited sun exposure and intake, use of medication and endocrine perturbations. Although there are several biological plausible mechanisms by which vitamin D may act upon musculoskeletal and cardiometabolic health, the impact of vitamin D insufficiency on such systems remains ill defined in SCI. In the absence of guidelines for the management of vitamin D insufficiency in this high-risk population and in an attempt to provide clinical guidance, considerations for vitamin D supplementation such as the type of vitamin D, dosing regimens and toxicity are discussed and tentative recommendations suggested with particular reference to issues faced by SCI patients.

CONCLUSION

Although high rates of vitamin D insufficiency are encountered in SCI individuals, its consequences and the amount of vitamin D required to prevent insufficiency are still unknown, indicating a need for more intervention studies with well-defined outcome measures. Routine screening and monitoring of vitamin D as well as treatment of suboptimal status should be instituted in both acute and chronic setting. The close interactions between vitamin D and related bone minerals should be kept in mind when supplementing SCI individuals, and practices should be individualized with clinical conditions.

Demographic and clinical characteristics of patients with spinal cord injury: a single hospital-based study

STUDY DESIGN

Retrospective study.

OBJECTIVES

To evaluate the demographic and clinical characteristics of patients diagnosed with spinal cord injury (SCI) admitted to a single center.

SETTING

Single center study, México.

METHODS

This study reviewed 433 patients with SCI. Data were extracted from medical records and retrospectively reviewed.

RESULTS

A total of 433 patients with a diagnosis of SCI were included in the analysis. Of these, 346 (79.9%) had traumatic SCI (TSCI) and 87 (20.1%) had non-traumatic SCI (NTSCI). The principal causes of traumatic TSCI were motor vehicle accidents in 150 patients (43.4%), falls in 107 patients (30.9%) and a result of firearms in 58 patients (16.8%). Tumoral cord compression was the main cause of NTSCI in 50 patients (57.4%), followed by degenerative disease-causing myelopathy in 17 patients (19.5%). The proportion of patients affected with NTSCI was significantly lower, 29.9 vs 79.1% (P=0.0001), the age of patients was higher 53.9 vs 37.8 (P<0.002) and SCI was less severe, AIS D 41.33 vs 9.5% (P=0.0001) compared with the TSCI group.

CONCLUSIONS

The demographic profiles of patients with TSCI and NTSCI differ in terms of proportion of total SCIs, patient age, male:female ratio and incomplete vs complete injury. The most common etiology of TSCI was motor vehicle accidents (43.4%), and neurological lesions were complete in 62.7% of patients. The most common etiology of NTSCI was tumoral spinal lesions (57.4%), and lesions were incomplete in 75.8% of patients.

New pharmacological approaches against chronic bowel and bladder problems in paralytics

Spinal cord injury (SCI) leads generally to an irreversible loss of sensory functions and voluntary motor control below injury level. Cures that could repair SCI and/or restore voluntary walking have not been yet developed nor commercialized. Beyond the well-known loss of walking capabilities, most SCI patients experience also a plethora of motor problems and health concerns including specific bladder and bowel dysfunctions. Indeed, chronic constipation and urinary retention, two significant life-threatening complications, are typically found in patients suffering of traumatic (e.g., falls or car accidents) or non-traumatic SCI (e.g., multiple sclerosis, spinal tumors). Secondary health concerns associated with these dysfunctions include hemorrhoids, abdominal distention, altered visceral sensitivity, hydronephrosis, kidney failure, urinary tract infections, sepsis and, in some cases, cardiac arrest. Consequently, individuals with chronic SCI are forced to regularly seek emergency and critical care treatments when some of these conditions occur or become intolerable. Increasing evidence supports the existence of a novel experimental approach that may be capable of preventing the occurrence or severity of bladder and bowel problems. Indeed, recent findings in animal models of SCI have revealed that, despite paraplegia or tetraplegia, it remains possible to elicit episodes of micturition and defecation by acting pharmacologically or electrically upon specialized lumbosacral neuronal networks, namely the spinal or sacral micturition center (SMC) and lumbosacral defecation center (LDC). Daily activation of SMC and LDC neurons could potentially become, new classes of minimally invasive treatments (i.e., if orally active) against these dysfunctions and their many life-threatening complications.