Effects of gender on neurologic and functional recovery after spinal cord injury

Clinical characteristics and prognostic factors of primary spinal subependymoma: a single-center cohort study and systematic review

PURPOSE

This study analyzed spinal subependymoma (SP-SE) cases to evaluate treatment outcomes and identify factors influencing patient outcomes.

METHOD

Clinical data from our institution, along with relevant literature, were reviewed and summarized. Univariate and multivariate logistic regression analyses were conducted to assess factors impacting the prognosis of patients with primary spinal ependymomas.

RESULTS

Our cohort included 16 males and 11 females, with a mean age of 46.2 ± 12.1 years. Tumors most commonly involved the thoracic spinal cord (37.0%) and an average of 4.8 segments. Approximately half of the tumors exhibited intramedullary to extramedullary growth (48.1%), and the tumors were predominantly eccentric in growth (85.2%). The median symptom duration was 48.0 months (IQR: 18.0-78.0 months), with limb weakness as the most frequent symptom. The median follow-up period was 61.0 months (IQR: 26.0-96.0 months). At the final follow-up, tumor regrowth occurred in 1 patient (3.7%), and 9 patients (33.3%) achieved good neurological outcomes (modified McCormick Scale [MSS] grades I). Multivariate logistic regression analysis revealed that tumors located at the T3-9 vertebral level were associated with worse postoperative neurological function (OR: 0.070, 95% Confidence Interval [CI]: 0.006-0.826, P = 0.035). Additionally, although the difference was not statistically significant, male gender also showed a trend towards an association with worse postoperative neurological function (OR: 0.126, 95% CI: 0.014-1.119, P = 0.063).

CONCLUSION

SP-SE generally follows a benign clinical course with favorable long-term survival. However, tumors located at T3-T9 and male patients tend to have worse postoperative neurological outcomes, requiring special attention during treatment.

Recovery after neurologic injury in operative acetabular and pelvic fractures: Defining the natural history of foot drop

INTRODUCTION

Dorsiflexion weakness, or footdrop, is a well-described sequela of high-energy acetabular and pelvic trauma, but little data exists describing the factors related to neurologic recovery and the timeline therein. An improved understanding of these factors would facilitate prognostication, patient education, and treatment decision-making. The aim of this study was to compare neurologic recovery between acetabular and pelvic fractures, delineate factors associated with recovery, and determine the expected timeline of recovery.

METHODS

A retrospective chart review was conducted at a level 1 tertiary referral center from 2000 to 2021 using CPT codes and keyword search functions to identify adult patients with neurologic injury in the setting of operative acetabular and/or pelvic ring trauma. Patients were included if they had documented, graded weakness not clearly explained by a concomitant injury (extremity or spine) following a pelvic/acetabular injury. Patients were followed to a minimum of 6 months follow-up or to neurologic recovery. Primary outcomes were the presence of motor recovery and time to initial and maximum recovery. The contributions of injury type and initial neurologic status were analyzed using logistic regression for impact on neurologic recovery.

RESULTS

We identified 121 patients with neurologic injury and resultant footdrop in the setting of an operative pelvic ring or acetabular fracture. From this cohort, 58 patients (47.9 %) demonstrated some degree of neurologic recovery in follow-up. There was no difference in recovery when comparing injury type (pelvis vs. acetabulum). Any motor function (including flicker) at time of initial evaluation was predictive of recovery (OR 6.18, [2.00 - 19.14]; p = 0.002). Initial neurologic function also correlated with more rapid recovery in comparison to patients with initial absent neurologic function both in time to initial recovery (56 days vs 107 days; p = 0.016) and time to maximum recovery (153 days vs 241 days; p = 0.027).

CONCLUSIONS

These results highlight the relatively poor prognosis for neurologic recovery in operative pelvic and acetabular injuries. Any initial neurologic function is predictive of likelihood of neurologic recovery and correlates with a more expedient neurologic recovery. Ultimately, this enables providers to better educate patients and facilitates decisions regarding further intervention.

Sex-specific alterations in functional connectivity and network topology in patients with degenerative cervical myelopathy

Patients with degenerative cervical myelopathy (DCM) experience structural and functional brain reorganization. However, few studies have investigated the influence of sex on cerebral alterations. The present study investigates the role of sex on brain functional connectivity (FC) and global network topology in DCM and healthy controls (HCs). The resting-state functional MRI data was acquired for 100 patients (58 males vs. 42 females). ROI-to-ROI FC and network topological features were characterized for each patient and HC. Group differences in FC and network topological features were examined. Compared to healthy counterparts, DCM males exhibited higher FC between vision-related brain regions, and cerebellum, brainstem, and thalamus, but lower FC between the intracalcarine cortex and frontal and somatosensory cortices, while DCM females demonstrated higher FC between the thalamus and cerebellar and sensorimotor regions, but lower FC between sensorimotor and visual regions. DCM males displayed higher FC within the cerebellum and between the posterior cingulate cortex (PCC) and vision-related regions, while DCM females displayed higher FC between frontal regions and the PCC, cerebellum, and visual regions. Additionally, DCM males displayed significantly greater intra-network connectivity and efficiency compared to healthy counterparts. Results from the present study imply sex-specific supraspinal functional alterations occur in patients with DCM.

Sex differences in spontaneous respiratory recovery following chronic C2 hemisection

Respiratory deficits after C2 hemisection (C2Hx) have been well documented through single-sex investigations. Although ovarian sex hormones enable enhanced respiratory recovery observed in females 2 wk post-C2Hx, it remains unknown if sex impacts spontaneous respiratory recovery at chronic time points. We conducted a longitudinal study to provide a comprehensive sex-based characterization of respiratory neuromuscular recovery for 8 wk after C2Hx. We recorded ventilation and chronic diaphragm electromyography (EMG) output in awake, behaving animals, phrenic motor output in anesthetized animals, and performed diaphragm muscle histology in chronically injured male and female rodents. Our results show that females expressed a greater recovery of tidal volume and minute ventilation compared with males during subacute and chronic time points. Eupneic diaphragm EMG amplitude during wakefulness and phrenic motor amplitude are similar between sexes at all time points after injury. Our data also suggest that females have a greater reduction in ipsilateral diaphragm EMG amplitude during spontaneous deep breaths (e.g., sighs) compared with males. Finally, we show evidence for atrophy and remodeling of the fast, fatigable fibers ipsilateral to injury in females, but not in males. To our knowledge, the data presented here represent the first study to report sex-dependent differences in spontaneous respiratory recovery and diaphragm muscle morphology following chronic C2Hx. These data highlight the need to study both sexes to inform evidence-based therapeutic interventions in respiratory recovery after spinal cord injury (SCI).NEW & NOTEWORTHY In response to chronic C2 hemisection, female rodents display increased tidal volume during eupneic breathing compared with males. Females show a greater reduction in diaphragm electromyography (EMG) amplitude during spontaneous deep breaths (e.g., sighs) and atrophy and remodeling of fast, fatigable diaphragm fibers. Given that most rehabilitative interventions occur in the subacute to chronic stages of injury, these results highlight the importance of considering sex when developing and evaluating therapeutics after spinal cord injury.

The secondary injury cascade after spinal cord injury: an analysis of local cytokine/chemokine regulation

After spinal cord injury, there is an extensive infiltration of immune cells, which exacerbates the injury and leads to further neural degeneration. Therefore, a major aim of current research involves targeting the immune response as a treatment for spinal cord injury. Although much research has been performed analyzing the complex inflammatory process following spinal cord injury, there remain major discrepancies within previous literature regarding the timeline of local cytokine regulation. The objectives of this study were to establish an overview of the timeline of cytokine regulation for 2 weeks after spinal cord injury, identify sexual dimorphisms in terms of cytokine levels, and determine local cytokines that significantly change based on the severity of spinal cord injury. Rats were inflicted with either a mild contusion, moderate contusion, severe contusion, or complete transection, 7 mm of spinal cord centered on the injury was harvested at varying times post-injury, and tissue homogenates were analyzed with a Cytokine/Chemokine 27-Plex assay. Results demonstrated pro-inflammatory cytokines including tumor necrosis factor α, interleukin-1β, and interleukin-6 were all upregulated after spinal cord injury, but returned to uninjured levels within approximately 24 hours post-injury, while chemokines including monocyte chemoattractant protein-1 remained upregulated for days post-injury. In contrast, several anti-inflammatory cytokines and growth factors including interleukin-10 and vascular endothelial growth factor were downregulated by 7 days post-injury. After spinal cord injury, tissue inhibitor of metalloproteinase-1, which specifically affects astrocytes involved in glial scar development, increased more than all other cytokines tested, reaching 26.9-fold higher than uninjured rats. After a mild injury, 11 cytokines demonstrated sexual dimorphisms; however, after a severe contusion only leptin levels were different between female and male rats. In conclusion, pro-inflammatory cytokines initiate the inflammatory process and return to baseline within hours post-injury, chemokines continue to recruit immune cells for days post-injury, while anti-inflammatory cytokines are downregulated by a week post-injury, and sexual dimorphisms observed after mild injury subsided with more severe injuries. Results from this work define critical chemokines that influence immune cell infiltration and important cytokines involved in glial scar development after spinal cord injury, which are essential for researchers developing treatments targeting secondary damage after spinal cord injury.

Changes in functional independence after inpatient rehabilitation in patients with spinal cord injury: A simultaneous evaluation of prognostic factors

OBJECTIVE

This study aimed to investigate the improvements of functional independence following inpatient rehabilitation and compare those improvements between different levels and severities of Spinal Cord Injury (SCI). Prognostic factors affecting the patient's outcomes were also studied.

SETTINGS

Rofeideh Rehabilitation Hospital.

OUTCOME MEASURES

Spinal Cord Independence Measure version III (SCIM III), and Functional Independence Measure (FIM).

METHOD

In this retrospective cohort study, 180 patients with SCI were enrolled to record their functional independence upon admission and discharge, and the changes were compared between different levels and severities of injury using non-parametric tests. The prognostic factors of outcomes were studied by generalized estimating equation (GEE) analysis.

RESULTS

The independence changes were significant for all the severities (American Spinal Injury Association Impairment Scale (AIS)) and levels of injury except for the patients with AIS A and B at upper cervical levels (P < 0.05). The level of injury, AIS, Length of Stay (LOS), and pressure ulcer had a significant prognostic value on patient's outcomes. Furthermore, there was a significant difference between different levels of injury with the same AIS grade in functional improvement (P < 0.05), while there was a significant difference between AIS groups with the same level of injury only at upper and middle cervical lesions (P < 0.05).

CONCLUSION

Recording the values of functional independence before and after rehabilitation in individuals with SCI can help clinicians approximately expect the outcomes of future patients. Moreover, a deeper study of the prognostic factors can provide a more logical expectation of rehabilitation outcomes.

Impact of Upper Limb Motor Recovery on Functional Independence After Traumatic Low Cervical Spinal Cord Injury

Cervical spinal cord injury (SCI) causes devastating loss of upper limb function and independence. Restoration of upper limb function can have a profound impact on independence and quality of life. In low-cervical SCI (level C5-C8), upper limb function can be restored via reinnervation strategies such as nerve transfer surgery. The translation of recovered upper limb motor function into functional independence in activities of daily living (ADLs), however, remains unknown in low cervical SCI (i.e., tetraplegia). The objective of this study was to evaluate the association of patterns in upper limb motor recovery with functional independence in ADLs. This will then inform prioritization of reinnervation strategies focused to maximize function in patients with tetraplegia. This retrospective study performed a secondary analysis of patients with low cervical (C5-C8) enrolled in the SCI Model Systems (SCIMS) database. Baseline neurological examinations and their association with functional independence in major ADLs-i.e., eating, bladder management, and transfers (bed/wheelchair/chair)-were evaluated. Motor functional recovery was defined as achieving motor strength, in modified research council (MRC) grade, of ≥ 3 /5 at one year from ≤ 2/5 at baseline. The association of motor function recovery with functional independence at one-year follow-up was compared in patients with recovered elbow flexion (C5), wrist extension (C6), elbow extension (C7), and finger flexion (C8). A multi-variable logistic regression analysis, adjusting for known factors influencing recovery after SCI, was performed to evaluate the impact of motor function at one year on a composite outcome of functional independence in major ADLs. Composite outcome was defined as functional independence measure score of 6 or higher (complete independence) in at least two domains among eating, bladder management, and transfers. Between 1992 and 2016, 1090 patients with low cervical SCI and complete neurological/functional measures were included. At baseline, 67% of patients had complete SCI and 33% had incomplete SCI. The majority of patients were dependent in eating, bladder management, and transfers. At one-year follow-up, the largest proportion of patients who recovered motor function in finger flexion (C8) and elbow extension (C7) gained independence in eating, bladder management, and transfers. In multi-variable analysis, patients who had recovered finger flexion (C8) or elbow extension (C7) had higher odds of gaining independence in a composite of major ADLs (odds ratio [OR] = 3.13 and OR = 2.87, respectively, p < 0.001). Age 60 years (OR = 0.44, p = 0.01), and complete SCI (OR = 0.43, p = 0.002) were associated with reduced odds of gaining independence in ADLs. After cervical SCI, finger flexion (C8) and elbow extension (C7) recovery translate into greater independence in eating, bladder management, and transfers. These results can be used to design individualized reinnervation plans to reanimate upper limb function and maximize independence in patients with low cervical SCI.

Sex Dependent Disparities in the Central Innate Immune Response after Moderate Spinal Cord Contusion in Rat

Subacute spinal cord injury (SCI) displays a complex pathophysiology associated with pro-inflammation and ensuing tissue damage. Microglia, the resident innate immune cells of the CNS, in concert with infiltrating macrophages, are the primary contributors to SCI-induced inflammation. However, subpopulations of activated microglia can also possess immunomodulatory activities that are essential for tissue remodeling and repair, including the production of anti-inflammatory cytokines and growth factors that are vital for SCI recovery. Recently, reports have provided convincing evidence that sex-dependent differences exist in how microglia function during CNS pathologies and the extent to which these cells contribute to neurorepair and endogenous recovery. Herein we employed flow cytometry and immunohistochemical methods to characterize the phenotype and population dynamics of activated innate immune cells within the injured spinal cord of age-matched male and female rats within the first week (7 days) following thoracic SCI contusion. This assessment included the analysis of pro- and anti-inflammatory markers, as well as the expression of critical immunomodulatory kinases, including P38 MAPK, and transcription factors, such as NFκB, which play pivotal roles in injury-induced inflammation. We demonstrate that activated microglia from the injured spinal cord of female rats exhibited a significantly diminutive pro-inflammatory response, but enhanced anti-inflammatory activity compared to males. These changes included lower levels of iNOS and TLR4 expression but increased levels of ARG-1 and CD68 in females after SCI. The altered expression of these markers is indicative of a disparate secretome between the microglia of males and females after SCI and that the female microglia possesses higher phagocytic capabilities (increased CD68). The examination of immunoregulatory kinases and transcription factors revealed that female microglia had higher levels of phosphorylated P38Thr180/Tyr182 MAPK and nuclear NFκB pp50Ser337 but lower amounts of nuclear NFκB pp65Ser536, suggestive of an attenuated pro-inflammatory phenotype in females compared to males after SCI. Collectively, this work provides novel insight into some of the sex disparities that exist in the innate immune response after SCI and indicates that sex is an important variable when designing and testing new therapeutic interventions or interpretating positive or negative responses to an intervention.

Guidelines for neuroprognostication in adults with traumatic spinal cord injury

BACKGROUND

Traumatic spinal cord injury (tSCI) impacts patients and their families acutely and often for the long term. The ability of clinicians to share prognostic information about mortality and functional outcomes allows patients and their surrogates to engage in decision-making and plan for the future. These guidelines provide recommendations on the reliability of acute-phase clinical predictors to inform neuroprognostication and guide clinicians in counseling adult patients with tSCI or their surrogates.

METHODS

A narrative systematic review was completed using Grading of Recommendations Assessment, Development, and Evaluation methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of an appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Timing/Setting question was framed as "When counseling patients or surrogates of critically ill patients with traumatic spinal cord injury, should < predictor, with time of assessment if appropriate > be considered a reliable predictor of < outcome, with time frame of assessment >?" Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an evidence profile and summary of findings, recommendations were based on four Grading of Recommendations Assessment, Development, and Evaluation criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. Good practice recommendations addressed essential principles of neuroprognostication that could not be framed in the Population/Intervention/Comparator/Outcome/Timing/Setting format. Throughout the guideline development process, an individual living with tSCI provided perspective on patient-centered priorities.

RESULTS

Six candidate clinical variables and one prediction model were selected. Out of 11,132 articles screened, 369 met inclusion criteria for full-text review and 35 articles met eligibility criteria to guide recommendations. We recommend pathologic findings on magnetic resonance imaging, neurological level of injury, and severity of injury as moderately reliable predictors of American Spinal Cord Injury Impairment Scale improvement and the Dutch Clinical Prediction Rule as a moderately reliable prediction model of independent ambulation at 1 year after injury. No other reliable or moderately reliable predictors of mortality or functional outcome were identified. Good practice recommendations include considering the complete clinical condition as opposed to a single variable and communicating the challenges of likely functional deficits as well as potential for improvement and for long-term quality of life with SCI-related deficits to patients and surrogates.

CONCLUSIONS

These guidelines provide recommendations about the reliability of acute-phase predictors of mortality, functional outcome, American Spinal Injury Association Impairment Scale grade conversion, and recovery of independent ambulation for consideration when counseling patients with tSCI or their surrogates and suggest broad principles of neuroprognostication in this context.

Comparison of One-Year Postinjury Mobility Outcomes Between Locomotor Training and Usual Care After Motor Incomplete Spinal Cord Injury

Objectives

To compare 1-year mobility outcomes of individuals with traumatic motor incomplete spinal cord injury (miSCI) who participated in standardized locomotor training (LT) within the first year of injury to those who did not.

Methods

This retrospective case-control analysis conducted with six US rehabilitation hospitals used SCI Model Systems (SCIMS) data comparing 1-year postinjury outcomes between individuals with miSCI who participated in standardized LT to those who received usual care (UC). Participants were matched on age, gender, injury year, mode of mobility, and rehabilitation center. The primary outcome is the FIM Total Motor score. Other outcomes include the FIM Transfer Index, FIM Stairs, and self-reported independence with household mobility, community mobility, and stairs.

Results

LT participants reported significantly better FIM Total Motor (difference = 2.812, 95% confidence interval [CI] = 5.896, 17.282) and FIM Transfer Index scores (difference = 0.958, 95% CI = 0.993, 4.866). No significant between-group differences were found for FIM Stairs (difference = 0.713, 95% CI = -0.104, 1.530) or self-reported household mobility (odds ratio [OR] = 5.065, CI = 1.435, 17.884), community mobility (OR = 2.933, 95% CI = 0.868, 9.910), and stairs (OR = 5.817, 95% CI = 1.424, 23.756) after controlling for multiple comparisons.

Conclusion

LT participants reported significantly greater improvements in primary and secondary measures of mobility and independence (FIM Total Motor score; FIM Transfer Index) compared to UC participants. Self-reported mobility outcomes were not significant between groups.

Effects of early mobilization within 48 hours of injury in patients with incomplete cervical spinal cord injury

OBJECTIVE

To investigate the effects of early mobilization within 48 h of injury on motor function and walking ability in patients with incomplete cervical spinal cord injury (SCI).

DESIGN

A retrospective observational study.

SETTING

Intensive care unit or high care unit of a university hospital emergency center.

PARTICIPANTS

Of 224 patients with SCI having American Spinal Injury Association impairment scale grades C and D, 158 consecutive patients hospitalized for at least 3 weeks after injury were included.

INTERVENTIONS

Patients were categorized into two groups: an early mobilization group in which patients were mobilized within 48 h of injury and a delayed mobilization group in which they were mobilized after 48 h of injury.

OUTCOME MEASURES

The upper extremity motor score (UEMS), lower extremity motor score (LEMS), and Walking Index for Spinal Cord Injury II (WISCI II) were compared using propensity score matching analysis.

RESULTS

Of the 158 patients who met the eligibility criteria, 32 were matched between the groups. There was a significant difference in the change in LEMS from the initial assessment to the assessment 2 weeks postoperatively in the early mobilization group (median 9 points vs. 3 points, p < 0.05). There were no significant differences in UEMS or WISCI II.

CONCLUSION

Early mobilization within 48 h may improve lower extremity motor function in patients with acute incomplete cervical SCI.

PTEN deletion in spinal pathways via retrograde transduction with AAV-RG enhances forelimb motor recovery after cervical spinal cord injury; Sex differences and late-onset pathophysiologies

Spinal cord injuries (SCI) cause permanent functional impairments due to interruption of motor and sensory pathways. Regeneration of axons does not occur due to lack of intrinsic growth capacity of adult neurons and extrinsic inhibitory factors, especially at the injury site. However, some regeneration can be achieved via deletion of the phosphatase and tensin homolog (PTEN) in cells of origin of spinal pathways. Here, we deployed an AAV variant that is retrogradely transported (AAV-rg) to deliver gene modifying cargos to the cells of origin of multiple pathways interrupted by SCI, testing whether this promoted recovery of motor function. PTENf/f;RosatdTomato mice and control RosatdTomato mice received injections of different doses (number of genome copies, GCs) of AAV-rg/Cre into the cervical spinal cord at the time of a C5 dorsal hemisection injury. Forelimb grip strength was tested over time using a grip strength meter. PTENf/f;RosatdTomato mice with AAV-rg/Cre (PTEN-deleted) exhibited substantial improvements in forelimb gripping ability in comparison to controls. Of note, there were major sex differences in the extent of recovery, with male mice exhibiting greater recovery than females. However, at around 5-7 weeks post-injury/injection, many mice with SCI and AAV-rg-mediated PTEN deletion began to exhibit pathophysiologies involving excessive scratching of the ears and back of the neck and rigid forward extension of the hindlimbs. These pathophysiologies increased in incidence and severity over time. Our results reveal that although intra-spinal injections of AAV-rg/Cre in PTENf/f;RosatdTomato mice can enhance forelimb motor recovery after SCI, late-developing functional abnormalities occur with the experimental conditions used here. Mechanisms underlying late-developing pathophysiologies remain to be defined.

Burden of Cardiovascular Risk in Individuals With Spinal Cord Injury and Its Association With Rehabilitation Outcomes: Results From the Swiss Spinal Cord Injury Cohort

OBJECTIVES

The aims of the study are to determine the cardiovascular risk burden rehabilitation discharge and to explore the association between recovery during rehabilitation and cardiovascular disease risk profile.

METHODS

We included adults without cardiovascular disease admitted for rehabilitation. We evaluated rehabilitation outcomes on admission and discharge. Cardiovascular disease risk profile was assessed by Framingham risk score, high-density lipoprotein, and fasting glucose level.

RESULTS

We analyzed data from 706 participants (69.6% men) with a median age of 53.5 yrs. The median time since injury was 14 days, and the admission length was 5.2 months. Majority had paraplegia (53.3%) and motor incomplete injury (53.7%). One third of the cohort had high cardiovascular risk profile before discharge. At discharge, poorer anthropometric measures were associated with higher Framingham risk score and lower high-density lipoprotein levels. Individuals with higher forced vital capacity (>2.72 l) and peak expiratory flow (>3.4 l/min) had 0.16 mmol/l and 0.14 mmol/l higher high-density lipoprotein compared with those with lower respiratory function, respectively. Individuals with higher mobility score (>12.5) and functional independence score (>74) had 0.21 and 0.18 mmol/l higher high-density lipoprotein compared with those with lower scores.

CONCLUSIONS

There is high cardiometabolic syndrome burden and cardiovascular disease risk profile upon rehabilitation discharge. Higher respiratory function, mobility, and overall independence were associated with better cardiovascular disease risk profile, although with study design limitations and short follow-up. Future studies should explore whether rehabilitation outcomes could be used to prioritize screening.

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CME OBJECTIVES

Upon reading this journal article, the reader is expected to: (1) Determine the burden of cardiometabolic disease in the early phase of spinal cord injury (SCI); (2) Differentiate the proposed SCI cutoff for high-risk obesity from the able-bodied population; and (3) Increase physicians' acuity for detecting cardiometabolic disease in their practice.

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.

Plasticity of colonic enteric nervous system following spinal cord injury in male and female rats

BACKGROUND

Neurogenic bowel is a dysmotility disorder following spinal cord injury (SCI) that negatively impacts quality of life, social integration, and physical health. Colonic transit is directly modulated by the enteric nervous system. Interstitial Cells of Cajal (ICC) distributed throughout the small intestine and colon serve as specialized pacemaker cells, generating rhythmic electrical slow waves within intestinal smooth muscle, or serve as an interface between smooth muscle cells and enteric motor neurons of the myenteric plexus. Interstitial Cells of Cajal loss has been reported for other preclinical models of dysmotility, and our previous experimental SCI study provided evidence of reduced excitatory and inhibitory enteric neuronal count and smooth muscle neural control.

METHODS

Immunohistochemistry for the ICC-specific marker c-Kit was utilized to examine neuromuscular remodeling of the distal colon in male and female rats with experimental SCI.

KEY RESULTS

Myenteric plexus ICC (ICC-MP) exhibited increased cell counts 3 days following SCI in male rats, but did not significantly increase in females until 3 weeks after SCI. On average, ICC-MP total primary arborization length increased significantly in male rats at 3-day, 3-week, and 6-week time points, whereas in females, this increase occurred most frequently at 6 weeks post-SCI. Conversely, circular muscle ICC (ICC-CM) did not demonstrate post-SCI changes.

CONCLUSIONS AND INFERENCES

These data demonstrate resiliency of the ICC-MP in neurogenic bowel following SCI, unlike seen in other related disease states. This plasticity underscores the need to further understand neuromuscular changes driving colonic dysmotility after SCI in order to advance therapeutic targets for neurogenic bowel treatment.

Administration of Tamoxifen Can Regulate Changes in Gene Expression during the Acute Phase of Traumatic Spinal Cord Injury

Traumatic spinal cord injury (SCI) causes irreversible damage leading to incapacity. Molecular mechanisms underlying SCI damage are not fully understood, preventing the development of novel therapies. Tamoxifen (TMX) has emerged as a promising therapy. Our aim was to identify transcriptome changes in the acute phase of SCI and the effect of Tamoxifen on those changes in a rat model of SCI. Four groups were considered: (1) Non-injured without TMX (Sham/TMX-), (2) Non-injured with TMX (Sham/TMX+), (3) injured without TMX (SCI/TMX-), and (4) injured with TMX (SCI/TMX+). Tamoxifen was administered intraperitoneally 30 min after injury, and spinal cord tissues were collected 24 h after injury. Clariom S Assays Array was used for transcriptome analysis. After comparing Sham/TMX- versus SCI/TMX-, 708 genes showed differential expression. The enriched pathways were the SCI pathway and pathways related to the inflammatory response. When comparing SCI/TMX- versus SCI/TMX+, only 30 genes showed differential expression, with no pathways enriched. Our results showed differential expression of genes related to the inflammatory response after SCI, and Tamoxifen seems to regulate gene expression changes in Ccr2 and Mmp12. Our study contributes data regarding the potential value of tamoxifen as a therapeutic resource for traumatic SCI during the acute phase.

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

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Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

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.

PTEN deletion in spinal pathways via retrograde transduction with AAV-rg enhances forelimb motor recovery after cervical spinal cord injury; sex differences and late-onset pathophysiologies

Spinal cord injuries (SCI) cause permanent functional impairments due to interruption of motor and sensory pathways. Regeneration of axons does not occur due to lack of intrinsic growth capacity of adult neurons and extrinsic inhibitory factors, especially at the injury site. However, some regeneration can be achieved via deletion of the phosphatase and tensin homolog (PTEN) in cells of origin of spinal pathways. Here, we deployed an AAV variant that is retrogradely transported (AAV-rg) to deliver gene modifying cargos to the cells of origin of multiple pathways interrupted by SCI, testing whether this promoted recovery of motor function. PTEN f/f ;Rosa tdTomato mice and control Rosa tdTomato mice received injections of different doses (number of genome copies, GCs) of AAV-rg/Cre into the cervical spinal cord at the time of a C5 dorsal hemisection injury. Forelimb grip strength was tested over time using a grip strength meter. PTEN f/f ;Rosa tdTomato mice with AAV-rg/Cre (PTEN-deleted) exhibited substantial improvements in forelimb gripping ability in comparison to controls. Of note, there were major sex differences in the extent of recovery, with male mice exhibiting greater recovery than females. However, at around 5-7 weeks post-injury/injection, many mice with SCI and AAV-rg-mediated PTEN deletion began to exhibit pathophysiologies involving excessive scratching of the ears and back of the neck and rigid forward extension of the hindlimbs. These pathophysiologies increased in incidence and severity over time. Our results reveal that although intra-spinal injections of AAV-rg/Cre in PTEN f/f ;Rosa tdTomato mice can enhance forelimb motor recovery after SCI, late-developing functional abnormalities occur with the experimental conditions used here. Mechanisms underlying late-developing pathophysiologies remain to be defined.

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

OBJECTIVE

To compare males and females who were stratified into subgroups corresponding to premenopausal, perimenopausal, and postmenopausal ages, regarding access to optimal care and their outcomes after traumatic spinal cord injury (tSCI).

STUDY DESIGN

Retrospective cohort study.

SETTING

Eighteen acute care centers and 13 rehabilitation facilities across Canada.

PARTICIPANTS

This study included 5571 individuals with tSCI at C1-L2 who were enrolled in the Rick Hansen Spinal Cord Injury Registry from July 2004 to September 2019 (N=5571). Females were compared with males in the younger (aged ≤40 years), middle-aged (ages 41-50), and older (aged >50 years) subgroups.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Females were compared with males in each subgroup with regard to their demographic data, pre-existing comorbidities, injury characteristics, management choices, access to optimal care, and clinical, neurologic, and functional outcomes after tSCI.

RESULTS

In the younger subgroups, females (n=408) were significantly younger, had a greater proportion of aboriginals and transportation-related tSCIs, underwent surgical treatment more often, and had a greater sensory score change than males (n=1613). In the middle-aged subgroups, females (n=174) had a greater proportion of high-thoracic tSCIs than males (n=666). In the older subgroups, females (n=660) were significantly older, had more fall-related and less severe tSCIs, had a shorter stay at the rehabilitation center, had less spasticity, and were discharged home less often than males (n=2050).

CONCLUSIONS

The results of this study suggest some sex-related differences in individuals' demographics and injury characteristics, but fewer discrepancies between females and males regarding their access to optimal care and outcomes after tSCI. Overall, future clinical trials could consider inclusion of males and females of all age groups to enhance recruitment and augment generalizability.

Determinants of Quality of Life in Individuals With Spinal Cord Injury Using Structural Equation Modeling

OBJECTIVE

The objective of this study is to examine the interdependent associations between International Classification of Functioning, Disability and Health (ICF) domains and their relationship with environmental factors with regard to quality of life (QoL) in individuals with spinal cord injury (SCI).

DESIGN

Survey, cross-sectional study, and model testing using structural equation modeling.

SETTING

Two inpatient and outpatient SCI rehabilitation units, Sheba Medical Center and Loewenstein Hospital, Israel.

PARTICIPANTS

Convenience sample of 156 individuals with SCI (N=156).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

QoL assessed by the World Health Organization Quality of Life Assessment-BREF. Neurological impairment after SCI reflected by lesion completeness and neurologic level of injury as measured by the International Standards for Neurological Classification of Spinal Cord Injury. The Spinal Cord Independence Measure to assess SCI-related task performance. ICF Brief Core Sets composition scores to assess impairment in body structure and function domains, limitations in activities, restriction in participation constructs, and the effect of environmental factors within the ICF model.

RESULTS

Level of spinal cord injury and ICF Brief Core Sets composite score relating to activities and participation construct demonstrated a direct significant association with QoL. Moreover, a significant indirect association with QoL was found between the composite scores in ICF body structure and function and environmental factors, level of spinal cord injury, time since injury onset, and sex. Because the Spinal Cord Independence Measure was not related to QoL, we inferred that the categories related to instrumental activities of daily living and participation exert the most significant influence on QoL.

CONCLUSIONS

In order to optimize improvements in quality of life, current rehabilitation programs should target limitations specifically related to instrumental activities of daily living and participation restrictions. It may serve as a focal point for further development of current therapeutic models and analytical methods that optimize rehabilitation planning and decision making among both health care professionals and patients.

A Scoping Review of the Characteristics of Activity-based Therapy Interventions Across the Continuum of Care for People Living With Spinal Cord Injury or Disease

Objective

To identify the characteristics of activity-based therapy (ABT) that individuals with spinal cord injury and disease (SCI/D) participate in across the continuum of care.

Data Sources

A search of 8 databases was conducted from inception to 4 March 2020: Medline, CINAHL, Embase, Emcare, PEDro, APA PsycINFO, Cochrane Database of Systematic Reviews, and the CENTRAL. The search strategy used terms identifying the population (SCI/D) and concept (ABT).

Study Selection

Original studies involving individuals with SCI/D ≥16 years of age participating in ABT interventions for >1 session were included in the review. The Joanna Briggs Institute guidelines for scoping reviews were followed. The initial search produced 2306 records. Title, abstract, and full-text screening by 2 independent reviewers yielded 140 articles.

Data Extraction

Data extraction was conducted by 3 independent reviewers and charted according to key themes. Data fields included participant demographics, ABT interventions, exercises, parameters, technology, and setting. Data synthesis included frequency counts and descriptive analysis of key themes.

Data Synthesis

Eighty percent of participants were male. Eighty-seven percent of studies included individuals with tetraplegia (26% exclusive). Fifty-six percent of studies occurred in a research lab. Fifty-four percent of studies were single modality interventions encompassing the whole body (71%). Sixteen main types of ABT exercises were identified. The most common were treadmill training (59%), muscle strengthening (36%), and overground walking (33%). Electrical stimulation (50%) and virtual reality (6%) were used in combination with an ABT exercise. Eighty-four types of parameters were identified. Six were general intervention parameters and 78 were specific to the type of ABT exercise. Sixteen main categories of technology were reported. The most common were motorized treadmills (47%) and transcutaneous electrical stimulation (44%).

Conclusions

The characteristics of ABT are diverse in scope. The results will inform the content to include in tools that track ABT participation and performance.

Sexual Dimorphism in Lesion Size and Sensorimotor Responses Following Spinal Cord Injury

Spinal cord injury (SCI) is a devastating disorder, which impacts the lives of millions of people worldwide with no clinically standardized treatment. Both pro-recovery and anti-recovery factors contribute to the overall outcome after the initial SCI. Sex is emerging as an important variable, which can affect recovery post-SCI. Contusion SCI at T10 was generated in male and female rats. Open-field Basso, Beattie, Bresnahan (BBB) behavioral test, Von Frey test, and CatWalk gate analysis were performed. Histological analysis was performed at the 45-day post-SCI end point. Male/female differences in sensorimotor function recovery, lesion size, and the recruitment of immune cells to the lesion area were measured. A group of males with less severe injuries was included to compare the outcomes for severity. Our results show that both sexes with the same injury level plateaued at a similar final score for locomotor function. Males in the less severe injury group recovered faster and plateaued at a higher BBB score compared to the more severe injury group. Von Frey tests show faster recovery of sensory function in females compared to both male groups. All three groups exhibited reduced mechanical response thresholds after SCI. The lesion area was significantly larger in the male group with severe injury than in females, as well as in males of less severe injury. No significant differences in immune cell recruitment were identified when comparing the three groups. The faster sensorimotor recovery and significantly smaller lesion area in females potentially indicate that neuroprotection against the secondary injury is a likely reason for sex-dependent differences in functional outcomes after SCI.

A Scoping Review of Registered Clinical Studies on Management of Individuals With Acute Spinal Cord Injury (2000-2020): Trends and Characteristics of the Research Initiatives

ABSTRACT

This scoping review examined the current trends and characteristics of the clinical research initiatives on the management of acute spinal cord injury. This review included all clinical studies on the acute treatment of spinal cord injury that were registered in the ClinicalTrials.gov website from February 2000 to December 2020. The search strategy combined the terms "acute spinal cord injury" and "treatment." There has been a gradual increase in the number of registered clinical studies on acute treatment of spinal cord injury over the past two decades. Of the 116 studies, there were 103 interventional studies, 12 observational studies, and 1 registry. While 115 clinical studies recruited male and female participants, most of the registered clinical studies included only adults with an upper age limit after spinal cord injury. Most of the registered clinical studies were interventional studies led by single institutions in North America (n = 70), Europe (n = 29), and Asia (n = 15). Most of the research initiatives were interventional studies on new therapies for management of individuals with spinal cord injury (n = 91). In conclusion, the results of this scoping review suggest that although there has been an increase in the amount and diversity of the research initiatives on treatment of acute spinal cord injury over the past two decades, their generalizability remains relatively limited.

Detection of locomotion deficit in a post-traumatic syringomyelia rat model using automated gait analysis technique

Syringomyelia (SM) is a spinal cord disorder in which a cyst (syrinx) filled with fluid forms in the spinal cord post-injury/disease, in patients syrinx symptoms include loss of pain and temperature sensation or locomotion deficit. Currently, there are no small animal models and connected tools to help study the functional impacts of SM. The objective of this study was to determine the detectability of subtle locomotion deficits due to syrinx formation/expansion in post-traumatic syringomyelia (PTSM) rat model using the recently reported method of Gait Analysis Instrumentation, and Technology Optimized for Rodents (GAITOR) with Automated Gait Analysis Through Hues and Areas (AGATHA) technique. First videos of the rats were collected while walking in an arena (using GAITOR) followed by extracting meaningful locomotion information from collected videos using AGATHA protocol. PTSM injured rats demonstrated detectable locomotion deficits in terms of duty factor imbalance, paw placement accuracy, step contact width, stride length, and phase dispersion parameters compared to uninjured rats due to SM. We concluded that this technique could detect mild and subtle locomotion deficits associated with PTSM injury, which also in future work could be used further to monitor locomotion responses after different treatment strategies for SM.

Early Trauma Predictors of Mobility in People with Spinal Cord Injury

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

This study aims to assess the potential value of very early trauma variables such as Abbreviated Injury Scale (AIS) and the Injury Severity Score for predicting independent ambulation following a traumatic spinal cord injury (TSCI).

SUMMARY OF BACKGROUND DATA

Several models for prediction of ambulation early after TSCI have been published and validated. The vast majority rely on the initial examination of American Spinal Injury Association (ASIA) impairment scale and level of injury; however, in many locations and clinical situations this examination is not feasible early after the injury.

METHODS

Patient characteristics, trauma data, and ASIA scores on admission to rehabilitation were collected for each of the 144 individuals in the study. Outcome measure was the indoor mobility item of the Spinal Cord Independence Measure taken upon discharge from rehabilitation. Univariate and multivariable models were created for each predictor, Odds ratios (ORs) were obtained by a multivariable logistic regression analysis, and area under the receiver operator curve was calculated for each model.

RESULTS

We observed a significant correlation between the trauma variables and independent ambulation upon discharge from rehabilitation. Of the early variables, the AIS for the spine region showed the strongest correlation.

CONCLUSION

These findings support using preliminary trauma variables for early prognostication of ambulation following a TSCI, allowing for tailored individual interventions.Level of Evidence: 3.

External Devices Among Individuals With Spinal Cord Injury From a Developing Country

OBJECTIVE

The aim of this study was to explore the proportion, number, and type of external devices (including mobility devices, ambulatory aides, and orthotics) possessed and used by individuals with spinal cord injury (SCI) from a developing country.

DESIGN

This was a cross-sectional study.

PARTICIPANTS

A total of 163 participants with SCI from several rural communities in a developing country participated in the study from June 2018 to August 2019.

METHODS

The participants were interviewed and assessed for their SCI characteristics and the external devices (i.e., mobility devices, ambulatory aides, and orthotics) they possessed and used in their daily living.

RESULTS

Most participants (85%), who lived in rural communities with a family income of less than $3167 per year, possessed external devices (one to five types), and 80% of all participants actually used the devices (one to three types) in their daily living. Most participants with motor-complete SCI used a single device, especially a manual wheelchair, whereas those with mild lesion severity used multiple devices for their daily activities, particularly a standard walker.

CONCLUSION

Owing to budget and environmental constraints, the external devices used by individuals with SCI from a developing country are different from those reported in a developed country. The findings provide particular insights into the management of external devices for these individuals of a developing country.

The Influence of Sex on Upper Extremity Joint Dynamics in Pediatric Manual Wheelchair Users With Spinal Cord Injury

INTRODUCTION

Manual wheelchair propulsion is a physically demanding task associated with upper extremity pain and pathology. Shoulder pain is reported in over 25% of pediatric manual wheelchairs users, and this number rises over the lifespan. Upper extremity biomechanics in adults has been associated with shoulder pain and pathology; however, few studies have investigated upper extremity joint dynamics in children. Furthermore, sex may be a critical factor that is currently unexplored with regard to pediatric wheelchair mobility.

OBJECTIVES

To investigate differences in upper extremity joint dynamics between pediatric male and female manual wheelchair users with spinal cord injury (SCI) during wheelchair propulsion.

METHODS

Novel instrumented wheelchair hand-rims synchronized with optical motion capture were used to acquire upper extremity joint dynamics of 20 pediatric manual wheelchair users with SCI (11 males, 9 females). Thorax, sternoclavicular, acromioclavicular, glenohumeral, elbow, and wrist joint kinematics and kinetics were calculated during wheelchair propulsion. Linear mixed models were used to assess differences between sexes.

RESULTS

Females exhibited significantly greater peak forearm pronation (p = .007), normalized wrist lateral force (p = .03), and normalized elbow posterior force (p = .04) than males. Males exhibited significantly greater peak sternoclavicular joint retraction (p < .001) than females. No significant differences between males and females were observed for the glenohumeral joint (p > .012).

CONCLUSION

This study found significant differences in upper extremity joint dynamics between sexes during manual wheelchair propulsion. Our results underscore the importance of considering sex when evaluating pediatric wheelchair mobility and developing comprehensive wheelchair training interventions for early detection and prevention of upper extremity pain and pathology.

Early Predictors of Neurological Outcomes After Traumatic Spinal Cord Injury: A Systematic Review and Proposal of a Conceptual Framework

BACKGROUND

Neurological outcomes after traumatic spinal cord injury are variable and depend on patient-, trauma-, and treatment-related factors as well as on spinal cord injury characteristics, imaging, and biomarkers.

OBJECTIVE

The aims of the study were to identify and classify the early predictors of neurological outcomes after traumatic spinal cord injury.

DATA SOURCES

The Medline, PubMed, Embase, and the Cochrane Central Database were searched using medical subject headings. The search was extended to the reference lists of identified studies.

STUDY ELIGIBILITY CRITERIA

The study eligibility criteria were assessment of neurological outcomes as primary or secondary outcome, predictors collected during the acute phase after traumatic spinal cord injury, and multivariate design.

PARTICIPANTS

The participants were adult patients with traumatic spinal cord injury followed at least 3 mos after injury.

STUDY APPRAISAL AND SYNTHESIS METHODS

The quality of studies was assessed by two independent reviewers using the Study Quality Assessment Tools for Observational Cohort and Cross-sectional Studies. The studies' narrative synthesis relied on a classification of the predictors according to quantity, quality, and consistency of the evidence. Results were summarized in a conceptual framework.

RESULTS

Forty-nine articles were included. The initial severity of traumatic spinal cord injury (American Spinal Injury Association Impairment Scale, motor score, and neurological level of injury) was the strongest predictor of neurological outcomes: patients with more severe injury at admission presented poor neurological outcomes. Intramedullary magnetic resonance imaging signal abnormalities were also associated with neurological outcomes, as the presence of intramedullary hemorrhage was a factor of poor prognosis. Other largely studied predictors, such as age and surgical timing, showed some inconsistency in results depending on cutoffs. Younger age and early surgery were generally associated with good outcomes. Although widely studied, other factors, such as vertebral and associated injuries, failed to show association with outcomes. Cerebrospinal fluid inflammatory biomarkers, as emerging factors, were significantly associated with outcomes.

CONCLUSIONS

This study provides a comprehensive review of predictors of neurological outcomes after traumatic spinal cord injury. It also highlights the heterogeneity of outcomes used by studies to assess neurological recovery. The proposed conceptual framework classifies predictors and illustrates their relationships with outcomes.

Obstetric Outcomes of Women Who Sustained Traumatic Spinal Injury during Pregnancy: A Systematic Review

Literature regarding pregnant women who sustained traumatic spinal injury during pregnancy is limited. Existing papers are mainly case reports, and this indicates a need for more high-quality research evidence in this area. Therefore, this study was designed to systematically review available literature that reported demographic information, clinical characteristics, and obstetric outcomes of women who sustained spinal injury during pregnancy. Studies published from the earliest record to January 2019, which reported traumatic spinal injury during pregnancy, were included. Studies that have reported pregnancy in patients with pre-existing spinal injury, review articles, commentaries, letter to editors, conference papers, and studies published in languages other than English were excluded. Sixteen studies reporting on 26 women were included. Their mean age was 26.7±5.5 years. Motor vehicle accidents were the main cause of spinal injury (n=15, 58%). Of the cases, four women sustained spinal injury during the 1st trimester of pregnancy, of which one had a spontaneous abortion, one delivered a baby with arthrogryposis multiplex congenital disorder, and the third one delivered a premature baby who died shortly after the delivery. Fifteen women sustained injury during their 2nd trimester, of which 14 delivered normal babies, while six sustained spinal injury during the 3rd trimester. Of these women, five delivered normal babies at term. Outcomes of pregnancy appear significantly affected if a spinal injury occurs during the 1st trimester of pregnancy; however, injuries sustained during the 2nd and 3rd trimesters can have good obstetric outcomes.

Characterizing Natural Recovery after Traumatic Spinal Cord Injury

The predominant tool used to predict outcomes after traumatic spinal cord injury (SCI) is the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), in association with the American Spinal Injury Association (ASIA) Impairment Scale (AIS). These measures have evolved based on analyses of large amounts of longitudinal neurological recovery data published in numerous separate studies. This article reviews and synthesizes published data on neurological recovery from multiple sources, only utilizing data in which the sacral sparing definition was applied for determination of completeness. Conversion from a complete to incomplete injury is more common in tetraplegia than paraplegia. The majority of AIS conversion and motor recovery occurs within the first 6-9 months, with the most rapid rate of motor recovery occurring in the first three months after injury. Motor score changes, as well as recovery of motor levels, are described with the initial strength of muscles as well as the levels of the motor zone of partial preservation influencing the prognosis. Total motor recovery is greater for patients with initial AIS B than AIS A, and greater after initial AIS C than with motor complete injuries. Older age has a negative impact on neurological and functional recovery after SCI; however, the specific age (whether >50 or >65 years) and underlying reasons for this impact are unclear. Penetrating injury is more likely to lead to a classification of a neurological complete injury compared with blunt trauma and reduces the likelihood of AIS conversion at one year. There are insufficient data to support gender having a major effect on neurological recovery after SCI.

Identification of Classes of Functioning Trajectories and Their Predictors in Individuals With Spinal Cord Injury Attending Initial Rehabilitation in Switzerland

Objectives

To identify classes of functioning trajectories in individuals with spinal cord injury (SCI) undergoing initial rehabilitation after injury and to examine potential predictors of class membership to inform clinical planning of the rehabilitation process.

Design

Longitudinal analysis of the individual's rehabilitation stay using data from the Inception Cohort of the Swiss Spinal Cord Injury Cohort Study (SwiSCI).

Setting

Initial rehabilitation in specialized centers in Switzerland.

Participants

Individuals with newly acquired SCI (N=748; mean age, 54.66±18.38y) who completed initial rehabilitation between May 2013 and September 2019. The cohort was primarily composed of men (67.51%), persons with paraplegia (56.15%), incomplete injuries (67.51%), and traumatic etiologies (55.48%).

Interventions

Not applicable.

Main Outcome Measures

Functioning was operationalized with the interval-based sum score of the Spinal Cord Independence Measure version III (SCIM III). For each individual, the SCIM III sum score was assessed at up to 4 time points during rehabilitation stay. The corresponding time of assessment was recorded by the difference in days between the SCIM III assessment and admission to the rehabilitation program.

Results

Latent process mixed model analysis revealed 4 classes of functioning trajectories within the present sample. Class-specific predicted mean functioning trajectories describe stable high functioning (n=307; 41.04%), early functioning improvement (n=39; 5.21%), moderate functioning improvement (n=287; 38.37%), and slow functioning improvement (n=115; 15.37%), respectively. Out of 12 tested factors, multinomial logistic regression showed that age, injury level, injury severity, and ventilator assistance were robust predictors that could distinguish between identified classes of functioning trajectories in the present sample.

Conclusions

The current study establishes a foundation for future research on the course of functioning of individuals with SCI in initial rehabilitation by identifying classes of functioning trajectories. This supports the development of specifically tailored rehabilitation programs and prediction models, which can be integrated into clinical rehabilitation planning.

Sex and gender gap in spinal cord injury research: Focus on cardiometabolic diseases. A mini review

Cardiometabolic disease (CMD) is among the leading causes of morbidity and mortality in people with a spinal cord injury (SCI). Despite well-acknowledged sex and gender differences in CMD in the general population, they remain insufficiently studied in persons with SCI. To describe the landscape of sex and gender in SCI research, we searched the literature for systematic reviews on cardiometabolic health in this population. Out of 15 systematic reviews identified, only 9 provided meaningful information on sex. Although one-quarter to one-fifth of the SCI population is female, women comprised only one-eighth to a quarter of study participants. A number of clinical studies purposively excluded women, to make the study population more homogenous. For those studies which included both sexes, in general, no sex-specific analyses were performed due to small sample sizes. All these reasons have contributed to the underrepresentation of females in the current body of evidence. Therefore, future studies should adopt a more sex- and gender-sensitive research framework to address cardiometabolic risk in SCI. Novel and advanced epidemiological methods should also be used, considering small sample sizes. Finally, collaborative research (through consortia and multi-center studies) should be encouraged to include more females. More inclusive research will ensure that everyone will benefit from scientific advancements, regardless of sex and gender.

Effects on Outcomes of Hyperglycemia in the Hyperacute Stage after Acute Traumatic Spinal Cord Injury

Hyperglycemia has adverse effects on neuronal recovery after brain injury, but its effects after spinal cord injury (SCI) are understudied. This retrospective cohort study examined the potential effects on outcomes of hyperglycemia in the hyperacute stage after acute traumatic SCI. This study included all individuals enrolled in the National Acute Spinal Cord Injury Study 3 (NASCIS-3). Glycemic levels at 24 h, at 48 h, and at day 7 after acute SCI were examined as potential determinants of survival, neurological outcomes (using NASCIS motor, sensory, and pain scores), and functional outcome (using the Functional Independence Measure [FIM]) within the first year post-SCI. Hyperglycemia was defined using two thresholds (140 mg/dL and 180 mg/dL). Study subjects were 76 females and 423 males with an overall mean age of 36 years who sustained mostly cervical SCI due to motor vehicle accidents or falls. Hyperglycemia diagnosed at day 7 post-injury was associated with significantly greater mortality rates post-SCI. Among the survivors, hyperglycemia during the hyperacute stage was not significantly correlated with neurological recovery post-SCI. Hyperglycemia persistent until day 7 was significantly correlated with lower functional scores post-SCI. These results suggest that hyperglycemia at day 7 is correlated with greater mortality rates within the first year post-SCI. Although hyperglycemia during the hyperacute stage was not associated with neurological recovery, hyperglycemia at day 7 may adversely affect functional recovery within the first year post-SCI. Future investigations are needed to determine the optimal glycemic target in the management of patients with SCI.

Time-to-treatment window and cross-sex potential of β2-adrenergic receptor-induced mitochondrial biogenesis-mediated recovery after spinal cord injury

Mitochondrial dysfunction is a well-characterized consequence of spinal cord injury (SCI). We previously reported that treatment with the FDA-approved β2-adrenergic receptor agonist formoterol beginning 8 h post-SCI induces mitochondrial biogenesis (MB) and improves body composition and locomotor recovery in female mice. To determine the time-to-treatment window of formoterol, female mice were subjected to 80 kdyn contusion SCI and daily administration of vehicle or formoterol (0.3 mg/kg) beginning 24 h after injury. This delayed treatment paradigm improved body composition in female mice by 21 DPI, returning body weight to pre-surgery weight and restoring gastrocnemius mass to sham levels; however, there was no effect on locomotor recovery, as measured by the Basso-Mouse Scale (BMS), or lesion volume. To assess the cross-sex potential of formoterol, injured male mice were treated with vehicle or formoterol (0.3 or 1.0 mg/kg) beginning 8 h after SCI. Formoterol also improved body composition post-SCI in male mice, restoring body weight and muscle mass regardless of dose. Interestingly, however, improved BMS scores and decreased lesion volume was observed only in male mice treated with 0.3 mg/kg. Additionally, 0.3 mg/kg formoterol induced MB in the gastrocnemius and injured spinal cord, as evidenced by increased MB protein expression and mitochondrial number. These data indicate that formoterol treatment improves recovery post-SCI in both male and female mice in a dose- and initiation time-dependent manner. Furthermore, formoterol-induced functional recovery post-SCI is not directly associated with peripheral effects, such as muscle mass and body weight.

Endocrine Therapy for the Functional Recovery of Spinal Cord Injury

Spinal cord injury (SCI) is a major cause of physical disability and leads to patient dissatisfaction with their quality of life. Patients with SCI usually exhibit severe clinical symptoms, including sensory and motor dysfunction below the injured levels, paraplegia, quadriplegia and urinary retention, which can exacerbate the substantial medical and social burdens. The major pathological change observed in SCI is inflammatory reaction, which induces demyelination, axonal degeneration, and the apoptosis and necrosis of neurons. Traditional medical treatments are mainly focused on the recovery of motor function and prevention of complications. To date, numerous studies have been conducted to explore the cellular and molecular mechanism of SCI and have proposed lots of effective treatments, but the clinical applications are still limited due to the complex pathogenesis and poor prognosis after SCI. Endocrine hormones are kinds of molecules that are synthesized by specialized endocrine organs and can participate in the regulation of multiple physiological activities, and their protective effects on several disorders have been widely discussed. In addition, many studies have identified that endocrine hormones can promote nerve regeneration and functional recovery in individuals with central nervous system diseases. Therefore, studies investigating the clinical applications of endocrine hormones as treatments for SCI are necessary. In this review, we described the neuroprotective roles of several endocrine hormones in SCI; endocrine hormone administration reduces cell death and promotes functional repair after SCI. We also proposed novel therapies for SCI.

Trends in Rates of ASIA Impairment Scale Conversion in Traumatic Complete Spinal Cord Injury

Recent studies of persons with spinal cord injury (SCI) report higher conversion rates of the American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades, especially for complete injuries. We examined the rate of conversion over time after complete SCI, accounting for demographic and injury characteristics. Subjects were 16 years of age and older with a complete SCI injury between 1995 and 2015, enrolled in the National SCI Database as day-1 admissions. We grouped subjects into 3-year intervals and assessed trends in conversion for the total sample and by tetraplegia (Tetra), high paraplegia (levels T1–9, HPara), and low paraplegia (levels T10–12, LPara).We used logistic regression to identify factors related to conversion such as age, sex, etiology, and level of injury. Of 2036 subjects, 1876 subjects had a follow-up examination between 30 and 730 days post-injury. Average age at injury was 34.2 ± 14.6 years; 79.8% were male, 44.6% Tetra, 35.3% HPara, and 20.1% LPara. There was a strong trend toward increased rates of conversion over time (p < 0.01 for all groups), especially for Tetra (to incomplete from 17.6% in 1995–1997 to 50% in 2013–2015, and to motor incomplete from 9.4% to 28.1%). Conversion rates for Para were less dramatic. There were increased odds of converting to incomplete for year of injury, level of injury (Tetra >LPara >HPara), non-violent etiology, and age (older is better). We found similar factors for conversion to motor incomplete, except sex was significant and etiology was not. Conversion rates from complete to incomplete and motor incomplete injury have been increasing, particularly for persons with tetraplegia. This has implications for acute clinical trials and for prognostication early after SCI.

Delayed microglial depletion after spinal cord injury reduces chronic inflammation and neurodegeneration in the brain and improves neurological recovery in male mice

Neuropsychological deficits, including impairments in learning and memory, occur after spinal cord injury (SCI). In experimental SCI models, we and others have reported that such changes reflect sustained microglia activation in the brain that is associated with progressive neurodegeneration. In the present study, we examined the effect of pharmacological depletion of microglia on posttraumatic cognition, depressive-like behavior, and brain pathology after SCI in mice.

Methods: Young adult male C57BL/6 mice were subjected to moderate/severe thoracic spinal cord contusion. Microglial depletion was induced with the colony-stimulating factor 1 receptor (CSF1R) antagonist PLX5622 administered starting either 3 weeks before injury or one day post-injury and continuing through 6 weeks after SCI. Neuroinflammation in the injured spinal cord and brain was assessed using flow cytometry and NanoString technology. Neurological function was evaluated using a battery of neurobehavioral tests including motor function, cognition, and depression. Lesion volume and neuronal counts were quantified by unbiased stereology.

Results: Flow cytometry analysis demonstrated that PLX5622 pre-treatment significantly reduced the number of microglia, as well as infiltrating monocytes and neutrophils, and decreased reactive oxygen species production in these cells from injured spinal cord at 2-days post-injury. Post-injury PLX5622 treatment reduced both CD45^int microglia and CD45^hi myeloid counts at 7-days. Following six weeks of PLX5622 treatment, there were substantial changes in the spinal cord and brain transcriptomes, including those involved in neuroinflammation. These alterations were associated with improved neuronal survival in the brain and neurological recovery.

Conclusion: These findings indicate that pharmacological microglia-deletion reduces neuroinflammation in the injured spinal cord and brain, improving recovery of cognition, depressive-like behavior, and motor function.

LncRNA Xist Contributes to Endogenous Neurological Repair After Chronic Compressive Spinal Cord Injury by Promoting Angiogenesis Through the miR-32-5p/Notch-1 Axis

Endogenous repair after chronic compressive spinal cord injury (CCSCI) is of great clinical interest. Ischemia-hypoxia-induced angiogenesis has been proposed to play an important role during this repair process. Emerging evidence indicates that long non-coding RNAs (lncRNAs) are involved in the pathophysiological processes of various diseases. Here, we identified a lncRNA (Xist; X-inactive specific transcript) with upregulated expression in cervical spine lesions during endogenous neurological repair in CCSCI rats. Therapeutically, the introduction of Xist to rats increased neurological function in vivo as assayed using the Basso, Beattie, and Bresnahan (BBB) score and inclined plane test (IPT). We found that the introduction of Xist enhanced endogenous neurological repair by promoting angiogenesis and microvessel density after CCSCI, while depletion of Xist inhibited angiogenesis and cell sprouting and migration. Mechanistically, Xist promoted angiogenesis by sponging miR-32-5p and modulating Notch-1 expression both in vitro and in vivo. These findings suggest a role of the Xist/miR-32-5p/Notch-1 axis in endogenous repair and provide a potential molecular target for the treatment of ischemia-related central nervous system (CNS) diseases.

Considerations for Studying Sex as a Biological Variable in Spinal Cord Injury

In response to NIH initiatives to investigate sex as a biological variable in preclinical animal studies, researchers have increased their focus on male and female differences in neurotrauma. Inclusion of both sexes when modeling neurotrauma is leading to the identification of novel areas for therapeutic and scientific exploitation. Here, we review the organizational and activational effects of sex hormones on recovery from injury and how these changes impact the long-term health of spinal cord injury (SCI) patients. When determining how sex affects SCI it remains imperative to expand outcomes beyond locomotor recovery and consider other complications plaguing the quality of life of patients with SCI. Interestingly, the SCI field predominately utilizes female rodents for basic science research which contrasts most other male-biased research fields. We discuss the unique caveats this creates to the translatability of preclinical research in the SCI field. We also review current clinical and preclinical data examining sex as biological variable in SCI. Further, we report how technical considerations such as housing, size, care management, and age, confound the interpretation of sex-specific effects in animal studies of SCI. We have uncovered novel findings regarding how age differentially affects mortality and injury-induced anemia in males and females after SCI, and further identified estrus cycle dysfunction in mice after injury. Emerging concepts underlying sexually dimorphic responses to therapy are also discussed. Through a combination of literature review and primary research observations we present a practical guide for considering and incorporating sex as biological variable in preclinical neurotrauma studies.

Pericytes improve locomotor recovery after spinal cord injury in male and female neonatal rats

OBJECTIVE

It is not known how activation of the hypoxia-inducible factor (HIF) pathway in pericytes, cells of the microvascular wall, influences new capillary growth. We tested the hypothesis that HIF-activated pericytes promote angiogenesis in a neonatal model of spinal cord injury (SCI).

METHODS

Human placental pericytes stimulated with cobalt chloride and naïve pericytes were injected into the site of a thoracic hemi-section of the spinal cord in rat pups on postnatal day three (P3). Hindlimb motor recovery and Doppler blood flow perfusion at the site of transection were measured on P10. Immunohistochemistry was used to visualize vessel and neurofilament density for quantification.

RESULTS

Injection of HIF-activated pericytes resulted in greater vascular density in males but did not result in improved motor function for males or females. Injection of non-HIF-activated pericytes resulted improved motor function recovery in both sexes (males, 2.722 ± 0.31-fold score improvement; females, 3.824 ± 0.58-fold score improvement, P < .05) but produced no significant changes in vessel density.

CONCLUSIONS

HIF-activated pericytes promote vascular density in males post-SCI. Acute delivery of non-HIF-activated pericytes at the site of injury can improve motor recovery post-SCI.

Examining the complexity of functioning in persons with spinal cord injury attending first rehabilitation in Switzerland using structural equation modelling

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To examine the associations between activities, body structures and functions, and their relationship with aetiology, age and sex in persons with spinal cord injury (SCI) at discharge from first rehabilitation.

SETTING

Swiss SCI Cohort Study (SwiSCI).

METHODS

The study included 390 participants with newly acquired SCI and the International Classification of Functioning, Disability and Health (ICF) as conceptual frame of reference. Body structures were represented by injury level and severity; body functions by cardiovascular, pulmonary, skin, bowel and urinary functions and pain; mental functions by anxiety, depression, optimism and self-esteem; and activities by independence in performing activities of daily living (ADL). Using structural equation modelling (SEM), indirect effects of body structures and functions on independence in performing ADL through mental functions were tested for each mental function separately. For each structural model, fit was assessed using several indices and differences in aetiology, age and sex groups were explored.

RESULTS

The structural model about optimism showed good fit in all indices; the models about anxiety, depression and self-esteem showed conflicting fit indices, respectively. Within all models, effects on independence in performing ADL were mainly direct. Pain showed significant (P < 0.05) indirect effects on independence in performing ADL within the depression, optimism and self-esteem models. The model about anxiety showed differences in aetiology groups.

CONCLUSIONS

Using an ICF-based modelling approach, this study presents an attempt towards a more comprehensive understanding of functioning in first rehabilitation of persons with SCI, which might be fundamental for rehabilitation planning.

Effects of a rehabilitation program for individuals with chronic spinal cord injury in Shanghai, China

Background

Specialized Institution-Based Rehabilitation (SIBR) is the cornerstone of care and treatment for individuals with spinal cord injury, but most people with chronic spinal cord injury (CSCI) living in China have no SIBR experience after acute care hospital discharge. In 2009, an SIBR facility was set up in Shanghai (China) to fill this important gap in care. The purpose of the study was to evaluate the effectiveness of an integrated rehabilitation training program among individuals with CSCI living in Shanghai.

Methods

A within-subject pre-posttest design was used to evaluate the SIBR. The sample included 455 individuals ≥1 year post-SCI, who were older than 18 years of age and were enrolled in a rehabilitation center in Shanghai, China, between 2013 and 2019. The data included individuals’ sociodemographic and injury characteristics, and twenty-three indicators were used as outcome measurements to evaluate basic life skills and their applications in family and social life. Multivariate linear regression was conducted to determine which factors might have influenced the effectiveness of the SIBR.

Results

All basic life skills and their applications in family and social life were improved, but with variations across socio-demographics. Female individuals with CSCI had better outcomes in basic life skills than did males. In terms of basic life skills and their applications in family and social life, individuals with a low level (thoracic or lumbosacral) of injury achieved more significant functional gains than those with a higher level (cervical). The baseline score was also a relevant factor in functional outcome.

Conclusions

Even for individuals with a long SCI history, SIBR training can improve basic life skills and the applications of those skills in family and social life settings.

A Long-Term Pilot Study on Sex and Spinal Cord Injury Shows Sexual Dimorphism in Functional Recovery and Cardio-Metabolic Responses

More than a quarter of a million individuals in the US live with spinal cord injury (SCI). SCI disrupts neural circuitry to vital organs in the body. Despite severe incidences of long-term peripheral complications from SCI, the cardio-metabolic consequences and divergences in sex-related responses are not well described. We examined the effects of SCI on functional recovery, cardiac structure and function, body composition, and glucose metabolism on adult female and male Sprague Dawley (SD) rats. SCI was induced at T10 via contusion. Measured outcomes include behavioral assessment, body weight, dual-energy X-ray absorptiometry (DEXA) for body composition, echocardiography for cardiac structure and function, intraperitoneal glucose tolerance test (IPGTT) for glucose metabolism, insulin tolerance test (ITT), and histology of cardiac structure at the endpoint. There was a decrease in body fat percentage in both sexes, with SCI females disproportionately affected in percent body fat change. Left ventricular internal diameter during systole (LVIDs) was decreased in SCI females more than in SCI males. No significant differences in glucose metabolism were observed up to 20 weeks post-injury (PI). These data show significant cardio-metabolic differences as a consequence of SCI and, furthermore, that sex is an underlying factor in these differences.

Effectiveness of occupational therapy in improving activities of daily living performance in complete cervical tetraplegic patients; A quasi experimental study

OBJECTIVE

To determine the effectiveness of Occupational therapy (OT) in improving activities of daily living performance in complete cervical tetraplegic patients.

METHODS

A quasi experimental study was conducted at Paraplegic Center Peshawar from May 2018 to March 2019. Seventy two spinal cord injury patients with complete cervical tetraplegia having age 18-60 years were included in the study using non probability convenience sampling technique. A trained Occupational therapist conducted two occupational therapy sessions per day, three times a week on alternative days for a period of six weeks. Self-care portion of Spinal cord injury independence measure (SCIM) was used to collect pre and post data. Data was analyzed using SPSS version 20.

RESULTS

Mean age of the participants was 30.21±13.52.Majority of the participants were (n= 61, 84.7%) male while remaining 11 (15.3%) participants were female. Pre self-care total score was 0.39±0.987 and post self-care total score was 7.17±5.536. There was significant differences (P value <0.05) between pre and post scores of feeding, upper & lower body bathing, upper & lower body dressing, grooming and total self-care scores.

CONCLUSION

Occupational therapy significantly improves activities of daily living performance in complete cervical tetraplegic spinal cord injury patients.

Inhibition of microRNA-711 limits angiopoietin-1 and Akt changes, tissue damage, and motor dysfunction after contusive spinal cord injury in mice

Spinal cord injury (SCI) causes neuronal cell death and vascular damage, which contribute to neurological dysfunction. Given that many biochemical changes contribute to such secondary injury, treatment approaches have increasingly focused on combined therapies or use of multi-functional drugs. MicroRNAs (miRs) are small (20-23 nucleotide), non-protein-coding RNAs and can negatively regulate target gene expression at the post-transcriptional level. As individual miRs can potentially modulate expression of multiple relevant proteins after injury, they are attractive candidates as upstream regulators of the secondary SCI progression. In the present study we examined the role of miR-711 modulation after SCI. Levels of miR-711 were increased in injured spinal cord early after SCI, accompanied by rapid downregulation of its target angiopoietin-1 (Ang-1), an endothelial growth factor. Changes of miR-711 were also associated with downregulation of the pro-survival protein Akt (protein kinase B), another target of miR-711, with sequential activation of glycogen synthase kinase 3 and the pro-apoptotic BH3-only molecule PUMA. Central administration of a miR-711 hairpin inhibitor after SCI limited decreases of Ang-1/Akt expression and attenuated apoptotic pathways. Such treatment also reduced neuronal/axonal damage, protected microvasculature and improved motor dysfunction following SCI. In vitro, miR-711 levels were rapidly elevated by neuronal insults, but not by activated microglia and astrocytes. Together, our data suggest that post-traumatic miR-711 elevation contributes to neuronal cell death after SCI, in part by inhibiting Ang-1 and Akt pathways, and may serve as a novel therapeutic target.

Decision tree analysis to better control treatment effects in spinal cord injury clinical research

OBJECTIVE

The aim of this study was to use decision tree modeling to identify optimal stratification groups considering both the neurological impairment and spinal column injury and to investigate the change in motor score as an example of a practical application. Inherent heterogeneity in spinal cord injury (SCI) introduces variation in natural recovery, compromising the ability to identify true treatment effects in clinical research. Optimized stratification factors to create homogeneous groups of participants would improve accurate identification of true treatment effects.

METHODS

The analysis cohort consisted of patients with acute traumatic SCI registered in the Vancouver Rick Hansen Spinal Cord Injury Registry (RHSCIR) between 2004 and 2014. Severity of neurological injury (American Spinal Injury Association Impairment Scale [AIS grades A-D]), level of injury (cervical, thoracic), and total motor score (TMS) were assessed using the International Standards for Neurological Classification of Spinal Cord Injury examination; morphological injury to the spinal column assessed using the AOSpine classification (AOSC types A-C, C most severe) and age were also included. Decision trees were used to determine the most homogeneous groupings of participants based on TMS at admission and discharge from in-hospital care.

RESULTS

The analysis cohort included 806 participants; 79.3% were male, and the mean age was 46.7 ± 19.9 years. Distribution of severity of neurological injury at admission was AIS grade A in 40.0% of patients, grade B in 11.3%, grade C in 18.9%, and grade D in 29.9%. The level of injury was cervical in 68.7% of patients and thoracolumbar in 31.3%. An AOSC type A injury was found in 33.1% of patients, type B in 25.6%, and type C in 37.8%. Decision tree analysis identified 6 optimal stratification groups for assessing TMS: 1) AOSC type A or B, cervical injury, and age ≤ 32 years; 2) AOSC type A or B, cervical injury, and age > 32-53 years; 3) AOSC type A or B, cervical injury, and age > 53 years; 4) AOSC type A or B and thoracic injury; 5) AOSC type C and cervical injury; and 6) AOSC type C and thoracic injury.

CONCLUSIONS

Appropriate stratification factors are fundamental to accurately identify treatment effects. Inclusion of AOSC type improves stratification, and use of the 6 stratification groups could minimize confounding effects of variable neurological recovery so that effective treatments can be identified.

Sex-related discrepancies in the epidemiology, injury characteristics and outcomes after acute spine trauma: A retrospective cohort study

Context/Objective: The potential effects of sex on injury severity and outcomes after acute spine trauma (AST) have been reported in pre-clinical and clinical studies, even though the data are conflicting. This study compared females and males regarding the epidemiology, injury characteristics, and clinical outcomes of AST. Design: Retrospective cohort study. Setting: Acute spine care quaternary center. Participants: All consecutive cases of AST admitted from January/1996 to December/2007 were included. Interventions: None. Outcome Measures: The potential effects of sex on the epidemiology, injury characteristics, and clinical outcomes of AST were studied. Results: There were 504 individuals with AST (161 females, 343 males; mean age of 49.44 ± 0.92 years). Sex was not associated with age or pre-existing co-morbidities as assessed using the Charlson Co-morbidity Index, however, females had a greater number of International Classifications of Diseases (ICD) codes at admission and higher Cumulative Illness Rating Scale (CIRS) than males. Over the 12-year period, the male-to-female ratio has not significantly changed. Although there were significant sex-related discrepancies regarding injury etiology, level and severity of AST, males and females had similar lengths of stay in the acute spine center, in-hospital survival post-AST, and need for mechanical ventilation and tracheostomy. Conclusion: This study suggests that females with AST present with a greater number of pre-existing co-morbidities, a higher frequency of thoraco-lumbar trauma, less severe neurological impairment and a greater proportion of MVA-related injuries. However, females and males have a similar length of stay in the acute spine center, and comparable in-hospital survival, need for mechanical ventilation, and tracheostomy after AST.

Inhibition of NOX2 signaling limits pain-related behavior and improves motor function in male mice after spinal cord injury: Participation of IL-10/miR-155 pathways

NADPH oxidase (NOX2) is an enzyme that induces reactive oxygen species (ROS) and serves as a switch between the pro-inflammatory and neurorestorative microglial/macrophage phenotypes; such changes play an important role in neuropathic pain and motor dysfunction. Increased NOX2 expression after spinal cord injury (SCI) has been reported, and inhibition of NOX2 improves motor function. However, the underlying mechanisms of NOX2 in post-traumatic pain and motor deficit remain unexplored. In the present study, we report that depletion of NOX2 (NOX2^-/-) or inhibition of NOX2 using NOX2ds-tat significantly reduced mechanical/thermal cutaneous hypersensitivity and motor dysfunction after moderate contusion SCI at T10 in male mice. Western blot (WB, 3 mm lesion area) and immunohistochemistry (IHC) showed that SCI elevates NOX2 expression predominantly in microglia/macrophages up to 8 weeks post-injury. Deletion of NOX2 significantly reduced CD11b⁺/CD45^hiF4/80⁺ macrophage infiltration at 24 h post-injury detected by flow cytometry and 8-OHG⁺ ROS production at 8 weeks post-injury by IHC in both lesion area and lumbar enlargement. NOX2 deficiency also altered microglial/macrophage pro-inflammatory and anti-inflammatory balance towards the neurorestorative response. WB analysis showed robust increase of Arginase-1 and YM1 proteins in NOX2^-/- mice. Furthermore, qPCR analysis showed significant up-regulation of anti-inflammatory cytokine IL-10 levels in NOX2^-/- mice, associated with reduced microRNA-155 expression. These findings were confirmed in CD11b⁺ microglia/macrophages isolated from spinal cord at 3 days post-injury. Taken together, our data suggest an important role for IL-10/miR-155 pathway in regulating NOX2-mediated SCI-dysfunction. Thus, specific targeting of NOX2 may provide an effective strategy for treating neurological dysfunction in SCI patients.

Spinal Cord Injury in Rats Dysregulates Diurnal Rhythms of Fecal Output and Liver Metabolic Indicators

Spinal cord injury (SCI) dysregulates metabolic homeostasis. Metabolic homeostasis is optimized across the day by the circadian system. Despite the prevalence of metabolic pathologies after SCI, post-SCI circadian regulation of metabolism remains understudied. Here, we hypothesized that SCI in rats would disrupt circadian regulation of key metabolic organs, leading to metabolic dysregulation. Female and male Sprague-Dawley rats received moderate thoracic (T)-9 contusion SCI (or sham surgery). First, SCI disrupted diurnal rhythms in two metabolic behaviors: fecal production and food intake rhythms were ablated acutely. SCI also expedited whole-gut transit time. In parallel, acute SCI increased plasma glucose. Diurnal glucose storage-release cycles regulated by the liver were disrupted by SCI, which also increased liver glucose metabolism messenger RNAs (mRNAs). Further, SCI disrupted liver clock gene expression and suppressed inflammatory gene rhythms. Together, our novel data suggest that SCI disrupts typical metabolic and circadian function. Improving post-SCI metabolic function could enhance recovery of homeostasis.

Feasibility of predicting improvements in motor function following SCI using the SCAR outcome measure: a retrospective study

STUDY DESIGN

A retrospective study.

OBJECTIVES

To assess improvement in volitional motor function after SCI, using The Spinal Cord Ability Ruler (SCAR) as a metric and investigate participant characteristics and recovery of motor functioning.

SETTING

A highly-specialized SCI rehabilitation unit (Spinal Cord Injury Centre of Western Denmark, SCIWDK).

METHODS

Retrospectively, data on all SCI patients admitted to SCIWDK between 1 January 1997 and 1 November 2018 were extracted from a database. The SCAR score (range: 0-100) was calculated by combining items from ISNCSCI and SCIM.

RESULTS

Mean (95%CI) improvement in volitional motor function was of 17.2 (CI: 14.5-19.9) equal to an improvement of 43% from baseline after median 155 days in-hospital rehabilitation. Individuals with tetraplegia exerted larger improvement (mean difference of 8.9 (CI: 3.6-14.2) points) as compared to paraplegia. Male gender predicted better improvement (p < 0.03), as did no need for mechanical ventilation with a gain of 8.5 (CI: 1.8-15.3) points as compared to those in need.

CONCLUSIONS

Overall mean improvement of 43% in volitional motor function was found in 84 in-hospitalized patients using SCAR as a metric at a highly-specialized SCI unit. Following factors; level-of-injury, gender, age, need of ventilation support predicted improvement in volitional motor function after a rehabilitation period. Results should be cautiously interpreted as a majority of hospitalized patients did not fulfill criteria for SCAR scoring. Prospectively designed studies with better internal validation and external validations are needed to confirm these findings.