Sex-Related Discrepancies in the Access to Optimal Care and Outcomes After Traumatic Spinal Cord Injury: A Retrospective Cohort Study Using Data From a Canadian Registry

Sex-related disparities in mobility, sensory function, and psychological outcomes in Wistar and Sprague-Dawley rats following spinal cord injury

Spinal cord injury (SCI) causes persistent motor, sensory, psychological, and bladder dysfunctions, with clinical evidence indicating better recovery in females compared to males. However, the mechanisms driving these sex-specific differences remain unclear. This study assessed sex- and strain-specific differences in recovery using Wistar and Sprague-Dawley (SD) rats. SCI was induced at the T10 spinal level via a contusion model, and functional recovery was evaluated through standardized tests for locomotion, sensory thresholds, psychological outcomes, and bladder function. Female rats demonstrated superior motor recovery, with higher Basso, Beattie & Bresnahan (BBB) scores and improved coordination, alongside improved sensory outcomes, evidenced by reduced mechanical pain sensitivity and longer thermal response latencies. Strain differences were observed, with SD rats exhibiting greater pain thresholds than Wistar rats. Females also showed improved bladder outcomes, including higher leak point pressure and reduced bladder volumes, while males displayed more pronounced depression-like behaviors. Cognitive performance did not differ significantly between sexes. These findings highlight sex-specific advantages in motor, sensory, and bladder function, as well as strain-dependent sensory differences, emphasizing the importance of considering sex and strain in designing targeted therapies for SCI rehabilitation.

Cross-species comparisons between pigs and mice reveal conserved sex-specific intraspinal inflammatory responses after spinal cord injury

OBJECTIVE

Therapeutic translation is challenging in spinal cord injury (SCI) and large animal models with high clinical relevance may accelerate therapeutic development. Pigs have important anatomical and physiological similarities to humans. Intraspinal inflammation mediates SCI pathophysiology. The purpose of this study was to evaluate the effect of sex on inflammation and outcomes in a pig thoracic contusion/compression SCI model.

METHODS

Adult (gonad-intact) male and female Yucatan miniature swine were subjected to either SCI or sham (laminectomy-only) injury.

RESULTS

SCI caused locomotor dysfunction (measured with the Porcine Thoracic Injury Behavior Score) with some recovery over 6 weeks and limited tissue sparing at 6 weeks with no difference between sexes. Immunohistological evaluations of spinal cord tissue at 2 days and 6 weeks post-injury revealed intraspinal microglia/macrophage (IBA-1, CD68) and lymphocyte responses (T-cells (CD3) and B-cells (CD79a)) consistent with observations in rodents and humans. Astrocyte (GFAP) immunoreactivity was observed within the lesion core at 6 weeks in contrast to observations in rodents. No differences were seen for astrocytes, microglia, macrophages, B-cells, and neutrophil infiltration between males and females. Intraspinal CD3 + T-cell counts and T-cell microclusters were significantly higher in females compared to males 6 weeks post-injury. Interestingly, we observed a similar significant increase in intraspinal CD3 + T-cell accumulation in female vs. male mice at 6 weeks post-thoracic contusion SCI.

INTERPRETATION

Our observations indicate that sex is a potential biological variable for T-cell infiltration and may contribute to sex-based differences in SCI pathophysiology and recovery outcomes.

Sex disparities in adverse outcomes after surgically managed isolated traumatic spinal injury

BACKGROUND

Traumatic spinal injury (TSI) encompasses a wide range of injuries affecting the spinal cord, nerve roots, bones, and soft tissues that result in pain, impaired mobility, paralysis, and death. There is some evidence suggesting that women may have different physiological responses to traumatic injury compared to men; therefore, this study aimed to investigate if there are any associations between sex and adverse outcomes following surgically managed isolated TSI.

METHODS

Using the 2013-2019 TQIP database, all adult patients with isolated TSI, defined as a spine AIS ≥ 2 with an AIS ≤ 1 in all other body regions, resulting from blunt force trauma requiring spinal surgery, were eligible for inclusion in the study. The association between the sex and in-hospital mortality as well as cardiopulmonary and venothromboembolic complications was determined by calculating the risk ratio (RR) after adjusting for potential confounding using inverse probability weighting.

RESULTS

A total of 43,756 patients were included. After adjusting for potential confounders, female sex was associated with a 37% lower risk of in-hospital mortality [adjusted RR (95% CI): 0.63 (0.57-0.69), p < 0.001], a 27% lower risk of myocardial infarction [adjusted RR (95% CI): 0.73 (0.56-0.95), p = 0.021], a 37% lower risk of cardiac arrest [adjusted RR (95% CI): 0.63 (0.55-0.72), p < 0.001], a 34% lower risk of deep vein thrombosis [adjusted RR (95% CI): 0.66 (0.59-0.74), p < 0.001], a 45% lower risk of pulmonary embolism [adjusted RR (95% CI): 0.55 (0.46-0.65), p < 0.001], a 36% lower risk of acute respiratory distress syndrome [adjusted RR (95% CI): 0.64 (0.54-0.76), p < 0.001], a 34% lower risk of pneumonia [adjusted RR (95% CI): 0.66 (0.60-0.72), p < 0.001], and a 22% lower risk of surgical site infection [adjusted RR (95% CI): 0.78 (0.62-0.98), p < 0.032], compared to male sex.

CONCLUSION

Female sex is associated with a significantly decreased risk of in-hospital mortality as well as cardiopulmonary and venothromboembolic complications following surgical management of traumatic spinal injuries. Further studies are needed to elucidate the cause of these differences.

Racial and Ethnical Discrepancies and Similarities in the Epidemiology, Survival, and Neurological Outcomes After Acute Traumatic Spinal Cord Injury: A Retrospective Cohort Study Using Data from the NASCIS-1 Trial

Background

Little is known about the impact of race/ethnicity on the clinical and neurological outcomes after acute traumatic spinal cord injury (tSCI).

Objectives

This study examined the influence of race/ethnicity on the individuals' survival and neurological recovery within the first year after tSCI.

Methods

The 306 cases enrolled in the First National Acute Spinal Cord Injury Study (NASCIS-1) were grouped as African American individuals (n = 84), non-Hispanic White individuals (n = 159), and other races/ethnicities that included Hispanic individuals (n = 60) and Asian individuals (n = 3). Outcome measures included survival and neurological recovery within the first year after tSCI. Data analyses were adjusted for major potential confounders.

Results

There were 39 females and 267 males with mean age of 31 years who mostly sustained cervical severe tSCI after motor vehicle accidents or falls. The three groups were comparable regarding sex distribution, level and severity of tSCI, level of consciousness at admission, and total received dose of methylprednisolone. African American individuals were significantly older than non-Hispanic White individuals (p = .0238). African American individuals and individuals of other races/ethnicities more often had a tSCI with open wound caused by missile and water-related accidents than non-Hispanic White individuals (p < .0001). Survival rates within the first year after tSCI were comparable among the three groups (p = .3191). Among the survivors, there were no significant differences among the three groups regarding motor and pinprick and light-touch sensory recovery (p > .0500).

Conclusions

The results of this study suggest that, while there were few differences among the racial/ethnical groups regarding the epidemiology of tSCI, race/ethnicity did not influence survival rate or neurological recovery within the first year post-tSCI.

Progress Report on the Spinal Cord Rehabilitation Research Initiatives Based on Registered Clinical Studies From 2000 to 2022

TO CLAIM CME CREDITS

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CME OBJECTIVES

Upon completion of this article, the reader should be able to: (1) Identify the most common trends and features of research studies on spinal cord rehabilitation, which were registered in the ClinicalTrials.gov Website between 2000 and 2022; (2) Discuss the main limitations of research on spinal cord rehabilitation, based on the protocols published on the ClinicalTrials.gov Website; and (3) Recognize important knowledge gaps in clinical studies on spinal cord rehabilitation that were registered in the ClinicalTrials.gov Website.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.