Restoration of sensorimotor functions after spinal cord injury

Monocentric Retrospective Analysis of Clinical Outcomes, Complications, and Adjacent Segment Disease in 507 Patients Undergoing Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy

BACKGROUND

Degenerative cervical myelopathy (DCM) is a leading cause of nontraumatic spinal cord injury. Surgery aims to arrest neurological decline and improve conditions, but controversies surround risks and benefits in elderly patients, outcomes in mild myelopathy, and the risk of adjacent segment disease (ASD).

METHODS

Retrospective data of patients who underwent anterior cervical discectomy and fusion for DCM in our hospital were collected. Patients were stratified by preoperative modified Japanese Orthopaedic Association (mJOA) (mild, moderate, severe) and age (under 70, over 70). Clinical outcomes, complications, and ASD rate were analyzed. We evaluated the relationship between mJOA recovery rate and the risk of complications and various preoperative parameters.

RESULTS

Five hundred seven consecutive patients were included in the study, with a mean follow-up of 43.52 months (12-71). Improvement in all outcome variables was observed in mild, moderate, and severe myelopathy categories, with elderly patients showing a lower improvement. Except for age, no other variable correlated with mJOA recovery rate. We observed 45 complications (11.1% of patients), with 14 in the U70 group and 31 in the O70 group (P value < 0.001). Age, Charlson comorbidity index, and ASA score were found to be predictors of complications. Fourteen patients (2.8% of total), mean age 54.2, developed radiological and clinical ASD. Most had cranial-level ASD with Pfirmann grade ≥ 2 before index surgery.

CONCLUSIONS

Most myelopathic patients improve after anterior cervical discectomy and fusion. Elderly patients show a lower improvement and higher complication rates than their younger counterparts. ASD rates are low, and younger patients with preexisting cranial level alterations are more susceptible.

Biomineralized MnO2 Nanoparticle-Constituted Hydrogels Promote Spinal Cord Injury Repair by Modulating Redox Microenvironment and Inhibiting Ferroptosis

Spinal cord injury (SCI) is one of the most severe injuries, characterized by multiple positive feedback regulatory signaling networks formed by oxidative stress and inflammation in the injury microenvironment, leading to neuronal cell damage and even death. Here, astragaloside IV (AS), known for its regulatory role in ferroptosis, was encapsulated in the cavity of apoferritin (HFn) after an in situ biomineralization process involving MnO2, resulting in the synthesis of HFn@MnO2/AS nanoparticles. These nanoparticles were then dispersed in chitosan/polyvinyl alcohol/glutaraldehyde/sodium β-glycerophosphate (CGPG) hydrogels to form CGPG-HFn@MnO2/AS injectable thermosensitive hydrogels that can scavenge reactive oxygen species (ROS) in the microenvironment. Our findings indicated that the prepared CGPG-HFn@MnO2/AS hydrogel exhibited remarkable efficacy in scavenging ROS in vitro, effectively ameliorating the oxidative stress microenvironment post-SCI. Furthermore, it inhibited oxidative stress-induced ferroptosis in vitro and in vivo by regulating SIRT1 signaling, thereby promoting neuronal cell migration and repair. Hence, the developed hydrogel combining MnO2 and AS exhibited multifaceted abilities to modulate the pathological microenvironment, providing a promising therapeutic strategy for central nervous system (CNS) diseases.

Long-Term Pulmonary Function Postspinal Cord Injury

OBJECTIVE

To investigate mean values of pulmonary function tests (PFT) at specific time points to assess long-term progression in patients with spinal cord injury (SCI).

DESIGN

Retrospective cohort study from 1997-2022.

SETTING

National rehabilitation hospital, providing scheduled admission for potential SCI-related issues. Follow-up assessments are recommended annually, guiding the observation period into consecutive 1-year intervals.

PARTICIPANTS

This study included 1394 adult patients who were admitted at least twice to the National Rehabilitation Center between 1997 and 2022, selected from an initial pool of 1510. Overall, 116 patients were excluded owing to the absence of any PFT results.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Changes in PFT values over time, specifically assessing for a potential 2-phase pattern after injury. The hypothesis that PFT values would initially improve before declining was formulated based on existing literature.

RESULTS

Significant changes in pulmonary function were noted among 1394 adults with SCI. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) initially increased within the first 1-2 years after injury but declined to below baseline levels after 6 years. Pronounced changes occurred between <1 year and 1-2 years after injury (FVC: Δ=4.89, SE=0.87, P<.001; FEV1: Δ=4.28, SE=1.09, P=.002) and 1-2 years to >6 years (FVC: Δ= -5.83, SE=0.94, P<.001; FEV1: Δ= -6.49, SE=1.18, P<.001). No significant changes in the FEV1/FVC ratio. Motor completeness was significantly associated with the increase and decline phase, showing a steeper increase and less decline compared with the motor-incomplete group.

CONCLUSIONS

Pulmonary function in SCI initially increases but declines over time, falling below initial levels by 6 years. Further evaluation with more complete datasets is warranted to elucidate the factors influencing these changes.

Pilot Study of Home-Based Virtual Reality Fitness Training in Post-Discharge Rehabilitation for Patients with Spinal Cord Injury: A Randomized Double-Blind Multicenter Trial

Spinal cord injury (SCI) patients require continuous rehabilitation post-discharge to ensure optimal recovery. This study investigates the effectiveness of home-based virtual reality fitness training (VRFT) as a convenient and accessible rehabilitation method for SCI patients. This randomized, double-blind, multicenter trial will enroll 120 participants, assigning them to either an 8-week VRFT program (exercise group) or a control group engaging in regular daily activities. The outcomes measured include muscle function, cardiopulmonary fitness, body composition, and physical performance. Our study will determine the safety and feasibility of VRFT in a home setting for SCI patients and evaluate whether these patients can effectively participate in such a program post-discharge. The results of this study are expected to inform future exercise protocols for SCI rehabilitation, offering valuable insights into the utility of VRFT as a therapeutic tool.

Identification and bioinformatics analysis of genes associated with pyroptosis in spinal cord injury of rat and mouse

The mechanism of spinal cord injury (SCI) is highly complex, and an increasing number of studies have indicated the involvement of pyroptosis in the physiological and pathological processes of secondary SCI. However, there is limited bioinformatics research on pyroptosis-related genes (PRGs) in SCI. This study aims to identify and validate differentially expressed PRGs in the GEO database, perform bioinformatics analysis, and construct regulatory networks to explore potential regulatory mechanisms and therapeutic targets for SCI. We obtained high-throughput sequencing datasets of SCI in rats and mice from the GEO database. Differential analysis was conducted using the "limma" package in R to identify differentially expressed genes (DEGs). These genes were then intersected with previously reported PRGs, resulting in a set of PRGs in SCI. GO and KEGG enrichment analyses, as well as correlation analysis, were performed on the PRGs in both rat and mouse models of SCI. Additionally, a protein-protein interaction (PPI) network was constructed using the STRING website to examine the relationships between proteins. Hub genes were identified using Cytoscape software, and the intersection of the top 5 hub genes in rats and mice were selected for subsequent experimentally validated. Furthermore, a competing endogenous RNA (ceRNA) network was constructed to explore potential regulatory mechanisms. The gene expression profiles of GSE93249, GSE133093, GSE138637, GSE174549, GSE45376, GSE171441_3d and GSE171441_35d were selected in this study. We identified 10 and 12 PRGs in rats and mice datasets respectively. Six common DEGs were identified in the intersection of rats and mice PRGs. Enrichment analysis of these DEGs indicated that GO analysis was mainly focused on inflammation-related factors, while KEGG analysis showed that the most genes were enriched on the NOD-like receptor signaling pathway. We constructed a ceRNA regulatory network that consisted of five important PRGs, as well as 24 miRNAs and 34 lncRNAs. This network revealed potential regulatory mechanisms. Additionally, the three hub genes obtained from the intersection were validated in the rat model, showing high expression of PRGs in SCI. Pyroptosis is involved in secondary SCI and may play a significant role in its pathogenesis. The regulatory mechanisms associated with pyroptosis deserve further in-depth research.

Celastrol inhibits oligodendrocyte and neuron ferroptosis to promote spinal cord injury recovery

BACKGROUND

Spinal cord injury (SCI) is a traumatic injury to the central nervous system and can cause lipid peroxidation in the spinal cord. Ferroptosis, an iron-dependent programmed cell death, plays a key role in the pathophysiology progression of SCI. Celastrol, a widely used antioxidant drug, has potential therapeutic value for nervous system.

PURPOSE

To investigate whether celastrol can be a reliable candidate for ferroptosis inhibitor and the molecular mechanism of celastrol in repairing SCI by inhibiting ferroptosis.

METHODS

First, a rat SCI model was constructed, and the recovery of motor function was observed after treatment with celastrol. The regulatory effect of celastrol on ferroptosis pathway Nrf2-xCT-GPX4 was detected by Western blot and immunofluorescence. Finally, the ferroptosis model of neurons and oligodendrocytes was constructed in vitro to further verify the mechanism of inhibiting ferroptosis by celastrol.

RESULTS

Our results demonstrated that celastrol promoted the recovery of spinal cord tissue and motor function in SCI rats. Further in vitro and in vivo studies showed that celastrol significantly inhibited ferroptosis in neurons and oligodendrocytes and reduced the accumulation of ROS. Finally, we found that celastrol could inhibit ferroptosis by up-regulating the Nrf2-xCT-GPX4 axis to repair SCI.

CONCLUSION

Celastrol effectively inhibits ferroptosis after SCI by upregulating the Nrf2-xCT-GPX4 axis, reducing the production of lipid ROS, protecting the survival of neurons and oligodendrocytes, and improving the functional recovery.

Transplantation of Wnt5a-modified Bone Marrow Mesenchymal Stem Cells Promotes Recovery After Spinal Cord Injury via the PI3K/AKT Pathway

Spinal cord injury (SCI) is a severe neurological condition that can lead to paralysis or even death. This study explored the potential benefits of bone marrow mesenchymal stem cell (BMSC) transplantation for repairing SCI. BMSCs also differentiate into astrocytes within damaged spinal cord tissues hindering the cell transplantation efficacy, therefore it is crucial to enhance their neuronal differentiation rate to facilitate spinal cord repair. Wnt5a, an upstream protein in the non-classical Wnt signaling pathway, has been implicated in stem cell migration, differentiation, and neurite formation but its role in the neuronal differentiation of BMSCs remains unclear. Thus, this study investigated the role and underlying mechanisms of Wnt5a in promoting neuronal differentiation of BMSCs both in vivo and in vitro. Wnt5a enhanced neuronal differentiation of BMSCs in vitro while reducing astrocyte differentiation. Additionally, high-throughput RNA sequencing revealed a correlation between Wnt5a and phosphoinositide 3-kinase (PI3K)/protein kinase B(AKT) signaling, which was confirmed by the use of the PI3K inhibitor LY294002 to reverse the effects of Wnt5a on BMSC neuronal differentiation. Furthermore, transplantation of Wnt5a-modified BMSCs into SCI rats effectively improved the histomorphology (Hematoxylin and eosin [H&E], Nissl and Luxol Fast Blue [LFB] staining), motor function scores (Footprint test and Basso-Beattie-Bresnahan [BBB]scores)and promoted neuron production, axonal formation, and remodeling of myelin sheaths (microtubule associated protein-2 [MAP-2], growth-associated protein 43 [GAP43], myelin basic protein [MBP]), while reducing astrocyte production (glial fibrillary acidic protein [GFAP]). Therefore, targeting the Wnt5a/PI3K/AKT pathway could enhance BMSC transplantation for SCI treatment.

Enhancing touch sensibility with sensory electrical stimulation and sensory retraining

A large proportion of stroke survivors suffer from sensory loss, negatively impacting their independence, quality of life, and neurorehabilitation prognosis. Despite the high prevalence of somatosensory impairments, our understanding of somatosensory interventions such as sensory electrical stimulation (SES) in neurorehabilitation is limited. We aimed to study the effectiveness of SES combined with a sensory discrimination task in a well-controlled virtual environment in healthy participants, setting a foundation for its potential application in stroke rehabilitation. We employed electroencephalography (EEG) to gain a better understanding of the underlying neural mechanisms and dynamics associated with sensory training and SES. We conducted a single-session experiment with 26 healthy participants who explored a set of three visually identical virtual textures-haptically rendered by a robotic device and that differed in their spatial period-while physically guided by the robot to identify the odd texture. The experiment consisted of three phases: pre-intervention, intervention, and post-intervention. Half the participants received subthreshold whole-hand SES during the intervention, while the other half received sham stimulation. We evaluated changes in task performance-assessed by the probability of correct responses-before and after intervention and between groups. We also evaluated differences in the exploration behavior, e.g., scanning speed. EEG was employed to examine the effects of the intervention on brain activity, particularly in the alpha frequency band (8-13 Hz) associated with sensory processing. We found that participants in the SES group improved their task performance after intervention and their scanning speed during and after intervention, while the sham group did not improve their task performance. However, the differences in task performance improvements between groups only approached significance. Furthermore, we found that alpha power was sensitive to the effects of SES; participants in the stimulation group exhibited enhanced brain signals associated with improved touch sensitivity likely due to the effects of SES on the central nervous system, while the increase in alpha power for the sham group was less pronounced. Our findings suggest that SES enhances texture discrimination after training and has a positive effect on sensory-related brain areas. Further research involving brain-injured patients is needed to confirm the potential benefit of our solution in neurorehabilitation.

Use of water- and land-based gait training to improve walking capacity in adults with complete spinal cord injury: A pilot study

OBJECTIVE

Little is known regarding the extent to which mobility can be improved using gait-based therapies in individuals with complete spinal cord injury (cSCI). Against this backdrop, the purpose of our study was to document changes in walking capacity following an extended period of underwater treadmill training (UTT) and supplemental overground walk training (OWT) in persons with cSCI.

DESIGN

Longitudinal design.

SETTING

University research center.

PARTICIPANTS

Five adults (mean age = 41.2 ± 5.9 years) with motor-complete (AIS A), chronic (mean years post-injury = 3.2 ± 1.6 years) cSCI who had not received epidural spinal cord stimulation (eSCS).

INTERVENTION

Participants underwent one year of UTT (3 walking bouts per day; 2-3 days per week). Once independent stepping activity in the water was observed, OWT, as tolerated, was performed prior to UTT.

OUTCOME MEASURE

Walking capacity was evaluated using the Walking Index for Spinal Cord Injury (WISCI-II) prior to UTT (Time 1: T1), six months after the start of UTT (Time 2: T2), and following completion of UTT (Time 3: T3).

RESULTS

Non-parametric analyses revealed a significant time effect (P < .05) for WISCI-II. Pre-planned comparisons revealed no difference in WISCI-II levels measured at T1 (0.20 ± 0.45) and T2 (4.80 ± 4.55) and at T2 (4.80 ± 4.55) and T3 (8.40 ± 1.34). However, the WISCI-II level obtained at T3 (8.40 ± 1.34) was significantly higher compared to the T1 value.

CONCLUSION

Our preliminary findings demonstrate that in the absence of eSCS, combined UTT and supplemental OWT can improve functional walking capacity in adults with cSCI.

ICF-linking and psychometric properties of upper extremity mobility outcome measures in spinal cord injury - a scoping review

OBJECTIVE

The purpose of this study was to explore the outcome measures used in upper extremity rehabilitation and research in spinal cord injury and to investigate their psychometry.

DESIGN

Scoping review.

DATA SOURCES

PubMed, the Cochrane library, PEDro, Medline (Ovid).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

The search process and study selection was carried out as follows: Firstly, a systematic search was carried out for articles on upper extremity rehabilitation after SCI. Performance or observational outcome measures which were designed for a clinical setting were collected from selected studies. Secondly, eligible outcome measures were linked to the ICF. The ICF-linked outcome measures were further screened for inclusion according to how comprehensively they covered ICF categories. Finally, a search of the selected outcome measures was performed to investigate their psychometry.

RESULTS

A total of four outcome measures and nine psychometric studies were selected for the scoping review; six studies addressed GRASSP, one addressed AuSpinal, one addressed SHFT and one addressed TRI-HFT. Of the 13 COSMIN measurement properties, studies of GRASSP covered seven, AuSpinal covered five and both SHFT and TRI-HFT covered three properties.

CONCLUSIONS

The psychometric properties of GRASSP were most extensively studied showing eligible reliability and validity. Although there are still some measurement properties to be explored, GRASSP can be recommended for use in the evaluation of upper extremity mobility in the SCI rehabilitation and research. More research is needed on the psychometrics of other outcome measures in people with spinal cord injuries before the outcome measures can be unconditionally recommended.

Htr2b Promotes M1 Microglia Polarization and Neuroinflammation after Spinal Cord Injury via Inhibition of Neuregulin-1/ErbB Signaling

The secondary injury of spinal cord injury (SCI) is dominated by neuroinflammation, which was caused by microglia M1 polarization. This study aimed to investigate the role and mechanism of Htr2b on neuroinflammation of SCI. The BV2 and HMC3 microglia were treated with lipopolysaccharide (LPS) or interferon (IFN)-γ to simulate in vitro models of SCI. Sprague-Dawley rats were subjected to the T10 laminectomy to induce animal model of SCI. Htr2b mRNA expression was measured by qRT-PCR. The expression of Htr2b and Iba-1 was detected by western blot and immunofluorescence. The expression of inflammatory cytokines in vitro and in vivo was also measured. Kyoto Encyclopedia of Genes and Genomes (KEGG) was employed to analyze Htr2b-regulated signaling pathways. Rat behavior was analyzed by the Basso, Beattie, and Bresnahan (BBB) and inclined plane test. Rat dorsal horn tissues were stained by hematoxylin-eosin (H&E) and Nissl to measure neuron loss. Htr2b was highly expressed in LPS- and IFN-γ-treated microglia and SCI rats. SCI modeling promoted M1 microglia polarization and increased levels of inflammatory cytokines. Inhibition of Htr2b by Htr2b shRNA or RS-127445 reduced the expression of Htr2b, Iba-1, and iNOS and suppressed cytokine levels. KEGG showed that Htr2b inhibited ErbB signaling pathway. Inhibition of Htr2b increased protein expression of neuregulin-1 (Nrg-1) and p-ErbB4. Inhibition of the ErbB signaling pathway markedly reversed the effect of Htr2b shRNA on M1 microglia polarization and inflammatory cytokines. Htr2b promotes M1 microglia polarization and neuroinflammation after SCI by inhibiting Nrg-1/ErbB signaling pathway.

Reliability of patient-specific gait profiles with inertial measurement units during the 2-min walk test in incomplete spinal cord injury

Most established clinical walking tests assess specific aspects of movement function (velocity, endurance, etc.) but are generally unable to determine specific biomechanical or neurological deficits that limit an individual's ability to walk. Recently, inertial measurement units (IMU) have been used to collect objective kinematic data for gait analysis and could be a valuable extension for clinical assessments (e.g., functional walking measures). This study assesses the reliability of an IMU-based overground gait analysis during the 2-min walk test (2mWT) in individuals with spinal cord injury (SCI). Furthermore, the study elaborates on the capability of IMUs to distinguish between different gait characteristics in individuals with SCI. Twenty-six individuals (aged 22-79) with acute or chronic SCI (AIS: C and D) completed the 2mWT with IMUs attached above each ankle on 2 test days, separated by 1 to 7 days. The IMU-based gait analysis showed good to excellent test-retest reliability (ICC: 0.77-0.99) for all gait parameters. Gait profiles remained stable between two measurements. Sensor-based gait profiling was able to reveal patient-specific gait impairments even in individuals with the same walking performance in the 2mWT. IMUs are a valuable add-on to clinical gait assessments and deliver reliable information on detailed gait pathologies in individuals with SCI.Trial registration: NCT04555759.

Effectiveness of Repetitive Transcranial Magnetic Stimulation Combined With Transspinal Electrical Stimulation on Corticospinal Excitability for Individuals With Incomplete Spinal Cord Injury: A Pilot Study

Repetitive Transcranial Magnetic Stimulation (rTMS) and transspinal electrical stimulation (tsES) have been proposed as a novel neurostimulation modality for individuals with incomplete spinal cord injury (iSCI). In this study, we integrated magnetic and electrical stimulators to provide neuromodulation therapy to individuals with incomplete spinal cord injury (iSCI). We designed a clinical trial comprising an 8-week treatment period and a 4-week treatment-free observation period. Cortical excitability, clinical features, inertial measurement unit and surface electromyography were assessed every 4 weeks. Twelve individuals with iSCI were recruited and randomly divided into a combined therapy group, a magnetic stimulation group, an electrical stimulation group, or a sham stimulation group. The magnetic and electric stimulations provided in this study were intermittent theta-burst stimulation (iTBS) and 2.5-mA direct current (DC) stimulation, respectively. Combined therapy, which involves iTBS and transspinal DC stimulation (tsDCS), was more effective than was iTBS alone or tsDCS alone in terms of increasing corticospinal excitability. In conclusion, the effectiveness of 8-week combined therapy in increasing corticospinal excitability faded 4 weeks after the cessation of treatment. According to the results, combination of iTBS rTMS and tsDCS treatment was more effective than was iTBS rTMS alone or tsDCS alone in enhancing corticospinal excitability. Although promising, the results of this study must be validated by studies with longer interventions and larger sample sizes.

Advances in Conductive Hydrogel for Spinal Cord Injury Repair and Regeneration

Spinal cord injury (SCI) treatment represents a major challenge in clinical practice. In recent years, the rapid development of neural tissue engineering technology has provided a new therapeutic approach for spinal cord injury repair. Implanting functionalized electroconductive hydrogels (ECH) in the injury area has been shown to promote axonal regeneration and facilitate the generation of neuronal circuits by reshaping the microenvironment of SCI. ECH not only facilitate intercellular electrical signaling but, when combined with electrical stimulation, enable the transmission of electrical signals to electroactive tissue and activate bioelectric signaling pathways, thereby promoting neural tissue repair. Therefore, the implantation of ECH into damaged tissues can effectively restore physiological functions related to electrical conduction. This article focuses on the dynamic pathophysiological changes in the SCI microenvironment and discusses the mechanisms of electrical stimulation/signal in the process of SCI repair. By examining electrical activity during nerve repair, we provide insights into the mechanisms behind electrical stimulation and signaling during SCI repair. We classify conductive biomaterials, and offer an overview of the current applications and research progress of conductive hydrogels in spinal cord repair and regeneration, aiming to provide a reference for future explorations and developments in spinal cord regeneration strategies.

Schwann Cell-Derived Exosomes and Methylprednisolone Composite Patch for Spinal Cord Injury Repair

Spinal cord injury (SCI) can cause permanent loss of sensory and motor function, and there is no effective clinical treatment, to date. Due to the complex pathological process involved after injury, synergistic treatments are very urgently needed in clinical practice. We designed a nanofiber scaffold hyaluronic acid hydrogel patch to release both exosomes and methylprednisolone to the injured spinal cord in a non-invasive manner. This composite patch showed good biocompatibility in the stabilization of exosome morphology and toxicity to nerve cells. Meanwhile, the composite patch increased the proportion of M2-type macrophages and reduced neuronal apoptosis in an in vitro study. In vivo, the functional and electrophysiological performance of rats with SCI was significantly improved when the composite patch covered the surface of the hematoma. The composite patch inhibited the inflammatory response through macrophage polarization from M1 type to M2 type and increased the survival of neurons by inhibition neuronal of apoptosis after SCI. The therapeutic effects of this composite patch can be attributed to TLR4/NF-κB, MAPK, and Akt/mTOR pathways. Thus, the composite patch provides a medicine-exosomes dual-release system and may provide a non-invasive method for clinical treatment for individuals with SCI.

DiSCIoser: unlocking recovery potential of arm sensorimotor functions after spinal cord injury by promoting activity-dependent brain plasticity by means of brain-computer interface technology: a randomized controlled trial to test efficacy

BACKGROUND

Traumatic cervical spinal cord injury (SCI) results in reduced sensorimotor abilities that strongly impact on the achievement of daily living activities involving hand/arm function. Among several technology-based rehabilitative approaches, Brain-Computer Interfaces (BCIs) which enable the modulation of electroencephalographic sensorimotor rhythms, are promising tools to promote the recovery of hand function after SCI. The "DiSCIoser" study proposes a BCI-supported motor imagery (MI) training to engage the sensorimotor system and thus facilitate the neuroplasticity to eventually optimize upper limb sensorimotor functional recovery in patients with SCI during the subacute phase, at the peak of brain and spinal plasticity. To this purpose, we have designed a BCI system fully compatible with a clinical setting whose efficacy in improving hand sensorimotor function outcomes in patients with traumatic cervical SCI will be assessed and compared to the hand MI training not supported by BCI.

METHODS

This randomized controlled trial will include 30 participants with traumatic cervical SCI in the subacute phase randomly assigned to 2 intervention groups: the BCI-assisted hand MI training and the hand MI training not supported by BCI. Both interventions are delivered (3 weekly sessions; 12 weeks) as add-on to standard rehabilitation care. A multidimensional assessment will be performed at: randomization/pre-intervention and post-intervention. Primary outcome measure is the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) somatosensory sub-score. Secondary outcome measures include the motor and functional scores of the GRASSP and other clinical, neuropsychological, neurophysiological and neuroimaging measures.

DISCUSSION

We expect the BCI-based intervention to promote meaningful cortical sensorimotor plasticity and eventually maximize recovery of arm functions in traumatic cervical subacute SCI. This study will generate a body of knowledge that is fundamental to drive optimization of BCI application in SCI as a top-down therapeutic intervention, thus beyond the canonical use of BCI as assistive tool.

TRIAL REGISTRATION

Name of registry: DiSCIoser: improving arm sensorimotor functions after spinal cord injury via brain-computer interface training (DiSCIoser).

TRIAL REGISTRATION NUMBER

NCT05637775; registration date on the ClinicalTrial.gov platform: 05-12-2022.

Perspectives on Data Sharing in Persons With Spinal Cord Injury

Open data sharing of clinical research aims to improve transparency and support novel scientific discoveries. There are also risks, including participant identification and the potential for stigmatization. The perspectives of persons participating in research are needed to inform open data-sharing policies. The aim of the current study was to determine perspectives on data sharing in persons with spinal cord injury (SCI), including risks and benefits, and types of data people are most willing to share. A secondary aim was to examine predictors of willingness to share data. Persons with SCIs in the United States and Canada completed a survey developed and disseminated through various channels, including our community partner, the North American Spinal Cord Injury Consortium. The study collected data from 232 participants, with 52.2% from Canada and 42.2% from the United States, and the majority completed the survey in English. Most participants had previously participated in research and had been living with an SCI for ≥5 years. Overall, most participants reported that the potential benefits of data sharing outweighed the negatives, with persons with SCI seen as the most trustworthy partners for data sharing. The highest levels of concern were that information could be stolen and companies might use the information for marketing purposes. Persons with SCI were generally supportive of data sharing for research purposes. Clinical trials should consider including a statement on open data sharing in informed consents to better acknowledge the contribution of research participants in future studies.

Gait training using a wearable robotic hip device for incomplete spinal cord injury: A preliminary study

CONTEXT/OBJECTIVE

To explore changes in gait functions for patients with chronic spinal cord injury (SCI) before and after standard rehabilitation and rehabilitation with a wearable hip device, explore the utility of robot-assisted gait training (RAGT), and evaluate the safety and dose of RAGT.

DESIGN

Single-arm, open-label, observational study.

SETTING

A rehabilitation hospital.

PARTICIPANTS

Twelve patients with SCI.

INTERVENTIONS

Standard rehabilitation after admission in the first phase. RAGT for two weeks in the second phase.

OUTCOME MEASURES

Self-selected walking speed (SWS), step length, cadence, and the 6-minute walking distance were the primary outcomes. Walking Index for SCI score, lower extremity motor score, and spasticity were measured. Walking abilities were compared between the two periods using a generalized linear mixed model (GLMM). Correlations between assessments and changes in walking abilities during each period were analyzed.

RESULTS

After standard rehabilitation for 66.1 ± 36.9 days, a period of 17.6 ± 3.3 days of RAGT was safely performed. SWS increased during both periods. GLMM showed that the increase in cadence was influenced by standard rehabilitation, whereas the limited step length increase was influenced by RAGT. During RAGT, the increase in step length was related to an increase in hip flexor function.

CONCLUSIONS

Gait speed in patients with SCI increased after rehabilitation, including RAGT, in the short-term. This increase was associated with improved muscle function in hip flexion at the start of RAGT.Trial Registration: This study was registered with the UMIN Clinical Trials Registry (UMIN-CTR; UMIN000042025).

Development of a New Control System for a Rehabilitation Robot Using Electrical Impedance Tomography and Artificial Intelligence

In this study, we present a tomography-based control system for a rehabilitation robot using a novel approach to assess advancement and a dynamic model of the system. In this model, the torque generated by the robot and the impedance of the patient's hand are used to determine each step of the rehabilitation. In the proposed control architecture, a regression model is developed and implemented based on the extraction of tomography signals to estimate the muscles state. During the rehabilitation session, the torque applied by the patient is adjusted according to this estimation. The first step of this protocol is to calculate the subject-specific parameters. These include the axis offset, inertia parameters, passive damping and stiffness. The second step involves identifying the other elements of the model, such as the torque resulting from interaction. In this case, the robot will calculate the torque generated by the patient. The developed robot-based solution and the suggested protocol were tested on different participants and showed promising results. First, the prediction of the impedance-position relationship was evaluated, and the prediction was below 2% error. Then, different participants with different impedances were tested, and the results showed that the control system controlled the force and position for each participant individually.

Efficacy of Wheelchair Skills Training Program in Enhancing Sitting Balance and Pulmonary Function in Chronic Tetraplegic Patients: A Randomized Controlled Study

Background and Objectives: This study aimed to evaluate the effectiveness of a wheelchair skills training program (WSTP) in improving sitting balance and pulmonary function in patients with chronic tetraplegia resulting from cervical spinal cord injury (cSCI). Materials and Methods: Twenty-four patients were randomly divided into WSTP and control groups. The WSTP group participated in the WSTP for eight weeks, while the control group underwent conventional physical therapy for the same eight-week period. Sitting balance was evaluated using the activity-based balance level evaluation (ABLE) scale, and pulmonary function was evaluated using forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF). Results: The WSTP group showed significant improvements in both sitting balance and pulmonary function during the intervention period (p < 0.05), whereas the control group did not show any significant changes. A strong positive correlation was found between ABLE scores and all three pulmonary function parameters across all time points. Conclusions: Our results suggest that the WSTP significantly improves sitting balance and specific aspects of lung function in patients with tetraplegia.

The effect of robot-assisted gait training for patients with spinal cord injury: a systematic review and meta-analysis

Background

With the aging of the global population, Spinal injuries are often prone to occur and affect human health. The development of technology has put robots on the stage to assist in the treatment of spinal injuries.

Methods

A comprehensive literature search were carried out in multiple databases, including PubMed, Medline (Ovid), Web of Science, Cochrane, Embase, Scopus, CKNI, Wang fang, VIP database, Sino Med, Clinical Trails until 20th, June, 2023 to collect effect of robot-assisted gait training for patients with spinal cord injury patients. Primary outcome includes any changes of gait distance and gait speed. Secondary outcomes include any changes in functions (Such as TUG, Leg strength, 10 MWT) and any advent events. Data were extracted from two independent individuals and Cochrane Risk of Bias tool version 2.0 was assessed for the included studies. Systematic review and meta-analysis were performed by RevMan 5.3 software.

Results

11 studies were included in meta-analysis. The result showed that gait distance [WMD = 16.05, 95% CI (-15.73, 47.83), I2 = 69%], gait speed (RAGT vs. regular treatment) [WMD = 0.01, 95% CI (-0.04, 0.05), I2 = 43%], gait speed (RAGT vs. no intervention) [WMD = 0.07, 95% CI (0.01, 0.12), I2 = 0%], leg strength [WMD = 0.59, 95% CI (-1.22, 2.40), I2 = 29%], TUG [WMD = 9.25, 95% CI (2.76, 15.73), I2 = 74%], 10 MWT [WMD = 0.01, 95% CI (-0.15, 0.16), I2 = 0%], and 6 MWT [WMD = 1.79, 95% CI (-21.32, 24.90), I2 = 0%].

Conclusion

Robot-assisted gait training seems to be helpful for patients with spinal cord to improve TUG. It may not affect gait distance, gait speed, leg strength, 10 MWT, and 6 MWT.

Spinal cord stimulation for spinal cord injury - Where do we stand? A narrative review

Recovery of function following a complete spinal cord injury (SCI) or an incomplete SCI where recovery has plateaued still eludes us despite extensive research. Epidural spinal cord stimulation (SCS) was initially used for managing neuropathic pain. It has subsequently demonstrated improvement in motor function in otherwise non-recovering chronic spinal cord injury in animal and human trials. The mechanisms of how it is precisely effective in doing so will need further research, which would help refine the technology for broader application. Transcutaneous spinal cord stimulation (TSCS) is also emerging as a modality to improve the functional outcome in SCI individuals, especially when coupled with appropriate rehabilitation. Apart from motor recovery, ESCS and TSCS have also shown improvement in autonomic, metabolic, genitourinary, and pulmonary function. Since the literature on this is still in its infancy, with no large-scale randomised trials and different studies using different protocols in a wide range of patients, a review of the present literature is imperative to better understand the latest developments in this field. This article examines the existing literature on the use of SCS for SCI individuals with the purpose of enabling functional recovery. It also examines the voids in the present research, thus providing future directions.

Application of Conductive Hydrogels on Spinal Cord Injury Repair: A Review

Spinal cord injury (SCI) causes severe motor or sensory damage that leads to long-term disabilities due to disruption of electrical conduction in neuronal pathways. Despite current clinical therapies being used to limit the propagation of cell or tissue damage, the need for neuroregenerative therapies remains. Conductive hydrogels have been considered a promising neuroregenerative therapy due to their ability to provide a pro-regenerative microenvironment and flexible structure, which conforms to a complex SCI lesion. Furthermore, their conductivity can be utilized for noninvasive electrical signaling in dictating neuronal cell behavior. However, the ability of hydrogels to guide directional axon growth to reach the distal end for complete nerve reconnection remains a critical challenge. In this Review, we highlight recent advances in conductive hydrogels, including the incorporation of conductive materials, fabrication techniques, and cross-linking interactions. We also discuss important characteristics for designing conductive hydrogels for directional growth and regenerative therapy. We propose insights into electrical conductivity properties in a hydrogel that could be implemented as guidance for directional cell growth for SCI applications. Specifically, we highlight the practical implications of recent findings in the field, including the potential for conductive hydrogels to be used in clinical applications. We conclude that conductive hydrogels are a promising neuroregenerative therapy for SCI and that further research is needed to optimize their design and application.

Advances in Spinal Cord Neuromodulation: The Integration of Neuroengineering, Computational Approaches, and Innovative Conceptual Frameworks

Spinal cord stimulation (SCS) is an approved treatment for intractable pain and has recently emerged as a promising area of research for restoring function after spinal cord lesion. This review will focus on the historical evolution of this transition and the path that remains to be taken for these methods to be rigorously evaluated for application in clinical practice. New developments in SCS are being driven by advances in the understanding of spinal cord lesions at the molecular, cellular, and neuronal levels, as well as the understanding of compensatory mechanisms. Advances in neuroengineering and the computational neurosciences have enabled the development of new conceptual SCS strategies, such as spatiotemporal neuromodulation, which allows spatially selective stimulation at precise time points during anticipated movement. It has also become increasingly clear that these methods are only effective when combined with intensive rehabilitation techniques, such as new task-oriented methods and robotic aids. The emergence of innovative approaches to spinal cord neuromodulation has sparked significant enthusiasm among patients and in the media. Non-invasive methods are perceived to offer improved safety, patient acceptance, and cost-effectiveness. There is an immediate need for well-designed clinical trials involving consumer or advocacy groups to evaluate and compare the effectiveness of various treatment modalities, assess safety considerations, and establish outcome priorities.

GDNF-Loaded Polydopamine Nanoparticles-Based Anisotropic Scaffolds Promote Spinal Cord Repair by Modulating Inhibitory Microenvironment

Spinal cord injury (SCI) is a devastating injury that causes permanent loss of sensation and motor function. SCI repair is a significant challenge due to the limited regenerating ability of adult neurons and the complex inflammatory microenvironment. After SCI, the oxidative stress induced by excessive reactive oxygen species (ROS) often leads to prolonged neuroinflammation that results in sustained damage to the spinal cord tissue. Polydopamine (PDA) shows remarkable capability in scavenging ROS to treat numerous inflammatory diseases. In this study, glial cell-derived neurotrophic factor (GDNF)-loaded PDA nanoparticle-based anisotropic scaffolds for spinal cord repair are developed. It is found that mesoporous PDA nanoparticles (mPDA NPs) in the scaffolds efficiently scavenge ROS and promote microglia M2 polarization, thereby inhibiting inflammatory response at the injury site and providing a favorable microenvironment for nerve cell survival. Furthermore, the GDNF encapsulated in mPDA NPs promotes corticospinal tract motor axon regeneration and its locomotor functional recovery. Together, findings from this study reveal that the GDNF-loaded PDA/Gelatin scaffolds hold potential as an effective artificial transplantation material for SCI treatment.

Use of Robot-Assisted Ankle Training in a Patient with an Incomplete Spinal Cord Injury: A Case Report

Rehabilitation interventions are crucial in promoting neuroplasticity after spinal cord injury (SCI). We provided rehabilitation with a single-joint hybrid assistive limb (HAL-SJ) ankle joint unit (HAL-T) in a patient with incomplete SCI. The patient had incomplete paraplegia and SCI (neurological injury height: L1, ASIA Impairment Scale: C, ASIA motor score (R/L) L4:0/0, S1:1/0) following a rupture fracture of the first lumbar vertebra. The HAL-T consisted of a combination of ankle plantar dorsiflexion exercises in the sitting position, knee flexion, and extension exercises in the standing position, and stepping exercises in the standing position with HAL assistance. The plantar dorsiflexion angles of the left and right ankle joints and electromyograms of the tibialis anterior and gastrocnemius muscles were measured and compared using a three-dimensional motion analyzer and surface electromyography before and after HAL-T intervention. Phasic electromyographic activity was developed in the left tibialis anterior muscle during plantar dorsiflexion of the ankle joint after the intervention. No changes were observed in the left and right ankle joint angles. We experienced a case in which intervention using HAL-SJ induced muscle potentials in a patient with a spinal cord injury who was unable to perform voluntary ankle movements due to severe motor-sensory dysfunction.

Neuromodulation with transcutaneous spinal stimulation reveals different groups of motor profiles during robot-guided stepping in humans with incomplete spinal cord injury

Neuromodulation via spinal stimulation has been investigated for improving motor function and reducing spasticity after spinal cord injury (SCI) in humans. Despite the reported heterogeneity of outcomes, few investigations have attempted to discern commonalities among individual responses to neuromodulation, especially the impact of stimulation frequencies. Here, we examined how exposure to continuous lumbosacral transcutaneous spinal stimulation (TSS) across a range of frequencies affects robotic torques and EMG patterns during stepping in a robotic gait orthosis on a motorized treadmill. We studied nine chronic motor-incomplete SCI individuals (8/1 AIS-C/D, 8 men) during robot-guided stepping with body-weight support without and with TSS applied at random frequencies between 1 and up to 100 Hz at a constant, individually selected stimulation intensity below the common motor threshold for posterior root reflexes. The hip and knee robotic torques needed to maintain the predefined stepping trajectory and EMG in eight bilateral leg muscles were recorded. We calculated the standardized mean difference between the stimulation conditions grouped into frequency bins and the no stimulation condition to determine changes in the normalized torques and the average EMG envelopes. We found heterogeneous changes in robotic torques across individuals. Agglomerative clustering of robotic torques identified four groups wherein the patterns of changes differed in magnitude and direction depending mainly on the stimulation frequency and stance/swing phase. On one end of the spectrum, the changes in robotic torques were greater with increasing stimulation frequencies (four participants), which coincided with a decrease in EMG, mainly due to the reduction of clonogenic motor output in the lower leg muscles. On the other end, we found an inverted u-shape change in torque over the mid-frequency range along with an increase in EMG, reflecting the augmentation of gait-related physiological (two participants) or pathophysiological (one participant) output. We conclude that TSS during robot-guided stepping reveals different frequency-dependent motor profiles among individuals with chronic motor incomplete SCI. This suggests the need for a better understanding and characterization of motor control profiles in SCI when applying TSS as a therapeutic intervention for improving gait.

Piperine attenuates the inflammation, oxidative stress, and pyroptosis to facilitate recovery from spinal cord injury via autophagy enhancement

Spinal cord injury (SCI) is a serious injury that can lead to irreversible motor dysfunction. Due to its complicated pathogenic mechanism, there are no effective drug treatments. Piperine, a natural active alkaloid extracted from black pepper, has been reported to influence neurogenesis and exert a neuroprotective effect in traumatic brain injury. The aim of this study was to investigate the therapeutic effect of piperine in an SCI model. SCI was induced in mice by clamping the spinal cord with a vascular clip for 1 min. Before SCI and every 2 days post-SCI, evaluations using the Basso mouse scale and inclined plane tests were performed. On day 28 after SCI, footprint analyses, and HE/Masson staining of tissues were performed. On a postoperative Day 3, the spinal cord was harvested to assess the levels of pyroptosis, reactive oxygen species (ROS), inflammation, and autophagy. Piperine enhanced functional recovery after SCI. Additionally, piperine reduced inflammation, oxidative stress, pyroptosis, and activated autophagy. However, the effects of piperine on functional recovery after SCI were reversed by autophagy inhibition. The study demonstrated that piperine facilitated functional recovery after SCI by inhibiting inflammatory, oxidative stress, and pyroptosis, mediated by the activation of autophagy.

An upconversion nanoparticle-integrated fibrillar scaffold combined with a NIR-optogenetic strategy to regulate neural cell performance

Optogenetics using light-sensitive proteins such as calcium transport channel rhodopsin (CatCh) opens up new possibilities for non-invasive remote manipulation of neural function. However, current optogenetic approaches for neurological disorder therapies rely on visible light excitation and are rarely applied to neurogenesis and nerve regeneration. Herein, we propose a new strategy for tissue engineering which combines optogenetic technology and biomimetic nerve scaffolds. Upconversion nanoparticles (UCNPs) were synthesized and integrated with oriented fibrillar PCL membranes with a collagen coating to establish neuro-matrix interfaces. Benefiting from the excellent bioactivity, oriented fibrillation and NIR-photoresponsivity, the CatCh-transfected PC12 cells on these interfaces exhibited enhanced cell elongation and neurite extension, as well as upregulated neurogenesis upon NIR excitation. Furthermore, a UCNP-integrated scaffold as an optogenetic actuator allowed NIR to penetrate dermal tissues to mediate neural activation, with an efficiency comparable to that of a 470 nm blue light. Compared with current visible light-excited optogenetics, our composite scaffold-mediated NIR stimulation addresses the problem of tissue penetration and will enable less-invasive neurofunctional manipulation, with the potential for remote therapy.

Activation of MAP2K signaling by genetic engineering or HF-rTMS promotes corticospinal axon sprouting and functional regeneration

Facilitating axon regeneration in the injured central nervous system remains a challenging task. RAF-MAP2K signaling plays a key role in axon elongation during nervous system development. Here, we show that conditional expression of a constitutively kinase-activated BRAF in mature corticospinal neurons elicited the expression of a set of transcription factors previously implicated in the regeneration of zebrafish retinal ganglion cell axons and promoted regeneration and sprouting of corticospinal tract (CST) axons after spinal cord injury in mice. Newly sprouting axon collaterals formed synaptic connections with spinal interneurons, resulting in improved recovery of motor function. Noninvasive suprathreshold high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) activated the BRAF canonical downstream effectors MAP2K1/2 and modulated the expression of a set of regeneration-related transcription factors in a pattern consistent with that induced by BRAF activation. HF-rTMS enabled CST axon regeneration and sprouting, which was abolished in MAP2K1/2 conditional null mice. These data collectively demonstrate a central role of MAP2K signaling in augmenting the growth capacity of mature corticospinal neurons and suggest that HF-rTMS might have potential for treating spinal cord injury by modulating MAP2K signaling.

Rehabilitation of People With Chronic Spinal Cord Injury Using a Laparoscopically Implanted Neurostimulator: Impact on Mobility and Urinary, Anorectal, and Sexual Functions

OBJECTIVES

This study aimed to assess the impact of the laparoscopic implantation of neuromodulation electrodes (Possover-LION procedure) on mobility and on sexual, urinary, and anorectal functions of people with chronic spinal cord injury (SCI).

MATERIAL AND METHODS

Longitudinal analysis of 30 patients with chronic SCI (21 ASIA impairment scale (AIS) A, eight AIS B, and one AIS C) submitted to the Possover-LION procedure for bilateral neuromodulation of femoral, sciatic, and pudendal nerves. Assessments were performed before the surgical procedure and at 3, 6, and 12 months postoperatively. The primary outcome was evolution in walking, measured by the Walking Index for Spinal Cord Injury score, preoperatively and at 12 months. Secondary outcomes were changes in overall mobility (Mobility Assessment Tool for Evaluation of Rehabilitation score), urinary function and quality of life (Qualiveen questionnaire), and bowel (time for bowel emptying proceedings and Wexner's Fecal Incontinence Severity Index [FISI]) and sexual functions (International Index of Erectile Function for men and Female Sexual Function Index for women). Surgical time, intraoperative bleeding, and perioperative complications were also recorded.

RESULTS

Qualitatively, 18 of 25 (72%) patients with thoracic injury and 3 of 5 (60%) patients with cervical injury managed to establish a walker-assisted gait at one-year follow-up (p < 0.0001). A total of 11 (47.8%) have improved in their urinary incontinence (p < 0.0001), and seven (30.4%) improved their enuresis (p = 0.0156). The FISI improved from a median of 9 points preoperatively to 5.5 at 12 months (p = 0.0056). Of note, 20 of 28 (71.4%) patients reported an improvement on genital sensitivity at 12 months postoperatively (p < 0.0001), but this was not reflected in sexual quality-of-life questionnaires.

CONCLUSIONS

Patients experienced improved mobility and genital sensitivity and a reduction in the number of urinary and fecal incontinence episodes. By demonstrating reproducible outcomes and safety, this study helps establish the Possover-LION procedure as an addition to the therapeutic armamentarium for the rehabilitation of patients with chronic SCI.

CLINICAL TRIAL REGISTRATION

This study was registered at the WHO Clinical Trials Database through the Brazilian Registry of Clinical Trials-REBEC (Universal Tracking Number: U1111-1261-4428).

Paving the way for a better management of pain in patients with spinal cord injury: An exploratory study on the use of Functional Electric Stimulation(FES)-cycling

CONTEXT/OBJECTIVE

Chronic pain is common in patients with spinal cord injury (SCI), for whom it negatively affects quality of life, and its treatment requires an integrated approach. To this end, lower limb functional electrical stimulation (FES) cycling holds promise.

OBJECTIVE

To investigate pain reduction in a sample of patients with SCI by means of lower limb rehabilitation using FES cycling.

DESIGN, SETTING AND PARTICIPANTS

Sixteen patients with incomplete and complete SCIs, attending the Neurorobotic Unit of our research institute and reporting pain at or below the level of their SCI were recruited to this exploratory study.

INTERVENTIONS

Patients undertook two daily sessions of FES cycling, six times weekly, for 6 weeks.

OUTCOME MEASURES

Pain outcomes were measured using the 0-10 numerical rating scale (NRS), the Multidimensional Pain Inventory for SCI (MPI-SCI), and the 36-Item Short Form Survey (SF-36). Finally, we assessed the features of dorsal laser-evoked potentials (LEPs) to objectively evaluate Aδ fiber pathways.

RESULTS

All participants tolerated the intervention well, and completed the training without side effects. Statistically significant changes were found in pain-NRS, MPI-SCI, and SF-36 scores, and LEP amplitudes. Following treatment, we found that three patients experienced high pain relief (an NRS decrease of at least 80%), six individuals achieved moderate pain relief (an NRS decrease of about 30-70%), and five participants had mild pain relief (an NRS decrease of less than 30%).

CONCLUSION

Our preliminary results suggest that FES cycling training is capable of reducing the pain reported by patients with SCI, regardless of American Spinal Injury Association scoring, pain level, or the neurological level of injury. The neurophysiological mechanisms underlying such effects are likely to be both spinal and supraspinal.

Systemic inflammation after spinal cord injury: A review of biological evidence, related health risks, and potential therapies

Individuals with chronic traumatic spinal cord injury (SCI) develop progressive multi-system health problems that result in clinical illness and disability. Systemic inflammation is associated with many of the common medical complications and acquired diseases that accompany chronic SCI, suggesting that it contributes to a number of comorbid pathological conditions. However, many of the mechanisms that promote persistent systemic inflammation and its consequences remain ill-defined. This review describes the significant biological factors that contribute to systemic inflammation, major organ systems affected, health risks, and the potential treatment strategies. We aim to highlight the need for a better understanding of inflammatory processes, and to establish appropriate strategies to address inflammation in SCI.

Therapy of spinal cord injury by folic acid polyethylene glycol amine-modified zeolitic imidazole framework-8 nanoparticles targeted activated M/Ms

Excessively activated microglia/macrophages (M/Ms) re-establish the proinflammatory microenvironment that exacerbates motor and/or sensory dysfunction after spinal cord injury (SCI). Thus, proinflammatory M/Ms-suppressed treatments may be effective strategies for SCI. However, the utilization of anti-inflammatory drugs for clinical approaches and biomedical research has side effects, such as nephrotoxicity and hepatotoxicity. In this study, we fabricated folic acid-polyethylene glycol (FA-PEG) amine-modified zeolitic imidazole framework-8 (ZIF-8) nanoparticles (FA-PEG/ZIF-8) and found that it effectively restored function in vivo. FA-PEG/ZIF-8 treatment significantly eliminated proinflammatory M/Ms without targeting other nerve cells and downregulated inflammation in the injured lesion. Furthermore, FA-PEG/ZIF-8 caused little toxicity in SCI mice compared to normal mice. These results suggest that FA-PEG/ZIF-8 has the potential to help recover from early-stage SCI by suppressing proinflammatory M/Ms.

Bu Shen Huo Xue decoction promotes functional recovery in spinal cord injury mice by improving the microenvironment to promote axonal regeneration

BACKGROUND

Bu-Shen-Huo-Xue (BSHX) decoction has been used in the postoperative rehabilitation of patients with spinal cord injury in China. In the present study, we aim to reveal the bioactive compounds in BSHX decoction and comprehensively explore the effects of BSHX decoction and the underlying mechanism in spinal cord injury recovery.

METHODS

The main chemical constituents in BSHX decoction were determined by UPLC-MS/MS. SCI mice were induced by a pneumatic impact device at T9-T10 level of the vertebra, and treated with BSHX decoction. Basso-Beattie-Bresnahan (BBB) score, footprint analysis, hematoxylin-eosin (H&E) staining, Nissl staining and a series of immunofluorescence staining were performed to investigate the functional recovery, glial scar formation and axon regeneration after BSHX treatment. Immunofluorescent staining of bromodeoxyuridine (BrdU), neuronal nuclei (NeuN) and glial fibrillary acidic protein (GFAP) was performed to evaluate the effect of BSHX decoction on neural stem cells (NSCs) proliferation and differentiation.

RESULTS

We found that the main compounds in BSHX decoction were Gallic acid, 3,4-Dihydroxybenzaldehyde, (+)-Catechin, Paeoniflorin, Rosmarinic acid, and Diosmetin. BSHX decoction improved the pathological findings in SCI mice through invigorating blood circulation and cleaning blood stasis in the lesion site. In addition, it reduced tissue damage and neuron loss by inhibiting astrocytes activation, and promoting the polarization of microglia towards M2 phenotype. The functional recovery test revealed that BSHX treatment improved the motor function recovery post SCI.

CONCLUSIONS

Our study provided evidence that BSHX treatment could improve the microenvironment of the injured spinal cord to promote axonal regeneration and functional recovery in SCI mice.

Analysis of temperaturepain sensitivity in patients with consequences of the cervical spinal cord injury

Background. The standard neurological assessment in patients with long-term consequences of spine-and-spinal cord injury and severe neurological deficit does not allow to accurately identify changes in sensitivity that determine the level, degree and nature of spinal cord injury, as well as to evaluate the minimal dynamics of these disorders with different treatment options. As a result, an objective instrumental assessment of the sensory sphere in the long-term period of spinal cord injury has not lost its relevance.The aim. To conduct an instrumental study of the temperature-pain sensitivity condition in patients with partial gross damage to the cervical spinal cord in the long-term period of the disease (type B on the ASIA scale).Methods. We examined 23 patients with consequences of vertebral fractures of the cervical spine in the late period of traumatic spinal cord disease, Grade B on the ASIA scale ASIA. The clinical analysis of sensitive disorders was performed according to ISNCSCI and ASIA scales. While studying the temperature-pain sensitivity the threshold of thermal sensitivity and the threshold of pain from hot were determined in СIV–SI dermatomes on the right and on the left using an electricesthesiometer.Results. The examined patients had hypesthesia of heat and pain sensitivity, hyperesthesia of pain sensitivity, thermoanesthesia and thermoanalgesia. The degree of changes in the temperature-pain sensitivity depended on the topographic localization of dermatomes. The more distally the study area was located from the level of damage, the more pronounced the disorders were. In 30.4 % of patients, the pain sensitivity from hot in the chain of dermatomes from CIV to SI was preserved on at least one side. The combination of thermoanesthesia with thermoanalgesia was observed in 69.6 % of cases in dermatomes with ThVII and distally.Conclusions. The instrumentally registered level of the temperature-pain sensitivity disorder did not correspond to clinically determined localization of sensory disorders. The range of discrepancy ranged from 2 to 12 dermatomes, with defining the sensitivity subclinical deficit over the area of clinical sensory disorders.

Responsiveness and minimal clinically important differences of the Trunk Assessment Scale for Spinal Cord injury (TASS)

OBJECTIVE

To confirm the responsiveness and minimal clinically important differences (MCIDs) of the Trunk Assessment Scale for Spinal Cord Injury (TASS).

PARTICIPANTS AND METHODS

We evaluated 48 Japanese individuals with spinal cord injury (SCI) (age 64.1 ± 10.4 yrs, 28 with tetraplegia) admitted to two institutions at admission, at 1 month of hospitalization, and at discharge with the TASS, the Trunk Control Test in individuals with an SCI (TCT-SCI) motor score, the Functional Independence Measure motor score (mFIM), and the Global Rating of Change Scale (GRCS). We assessed the TASS responsiveness by determining the correlation coefficients for the changes in the TASS' and other assessments' scores. We calculated the MCIDs by five anchor-based methods.

RESULTS

The changes in the TASS and those in the other assessments were weakly correlated at 1 month and moderately correlated at discharge. The TASS MCIDs were observed at 1 month and at discharge.

CONCLUSION

Our findings confirmed that the change in TASS scores had weak-to-moderate correlations with the changes in the participants' upper- and lower-limb function and activities of daily living. Using the MCID for the TASS determined by anchor-based methods may lead to a better interpretation of changes in the trunk function of individuals with SCIs.

Phenotypes of Motor Deficit and Pain after Experimental Spinal Cord Injury

Motor disability is a common outcome of spinal cord injury (SCI). The recovery of motor function after injury depends on the severity of neurotrauma; motor deficit can be reversible, at least partially, due to the innate tissue capability to recover, which, however, deteriorates with age. Pain is often a comorbidity of injury, although its prediction remains poor. It is largely unknown whether pain can attend motor dysfunction. Here, we implemented SCI for modelling severe and moderate neurotrauma and monitored SCI rats for up to 5 months post-injury to determine the profiles of both motor deficit and nociceptive sensitivity. Our data showed that motor dysfunction remained persistent after a moderate SCI in older animals (5-month-old); however, there were two populations among young SCI rats (1 month-old) whose motor deficit either declined or exacerbated even more over 4–5 weeks after identical injury. All young SCI rats displayed changed nociceptive sensitivity in thermal and mechanical modalities. The regression analysis of the changes revealed a population trend with respect to hyper- or hyposensitivity/motor deficit. Together, our data describe the phenotypes of motor deficit and pain, the two severe complications of neurotrauma. Our findings also suggest the predictability of motor dysfunction and pain syndromes following SCI that can be a hallmark for long-term rehabilitation and recovery after injury.

International surveillance study in acute spinal cord injury confirms viability of multinational clinical trials

BACKGROUND

The epidemiological international landscape of traumatic spinal cord injury (SCI) has evolved over the last decades along with given inherent differences in acute care and rehabilitation across countries and jurisdictions. However, to what extent these differences may influence neurological and functional recovery as well as the integrity of international trials is unclear. The latter also relates to historical clinical data that are exploited to inform clinical trial design and as potential comparative data.

METHODS

Epidemiological and clinical data of individuals with traumatic and ischemic SCI enrolled in the European Multi-Center Study about Spinal Cord Injury (EMSCI) were analyzed. Mixed-effect models were employed to account for the longitudinal nature of the data, efficiently handle missing data, and adjust for covariates. The primary outcomes comprised demographics/injury characteristics and standard scores to quantify neurological (i.e., motor and sensory scores examined according to the International Standards for the Neurological Classification of Spinal Cord Injury) and functional recovery (walking function). We externally validated our findings leveraging data from a completed North American landmark clinical trial.

RESULTS

A total of 4601 patients with acute SCI were included. Over the course of 20 years, the ratio of male to female patients remained stable at 3:1, while the distribution of age at injury significantly shifted from unimodal (2001/02) to bimodal distribution (2019). The proportional distribution of injury severities and levels remained stable with the largest percentages of motor complete injuries. Both, the rate and pattern of neurological and functional recovery, remained unchanged throughout the surveillance period despite the increasing age at injury. The findings related to recovery profiles were confirmed by an external validation cohort (n=791). Lastly, we built an open-access and online surveillance platform ("Neurosurveillance") to interactively exploit the study results and beyond.

CONCLUSIONS

Despite some epidemiological changes and considerable advances in clinical management and rehabilitation, the neurological and functional recovery following SCI has remained stable over the last two decades. Our study, including a newly created open-access and online surveillance tool, constitutes an unparalleled resource to inform clinical practice and implementation of forthcoming clinical trials targeting neural repair and plasticity in acute spinal cord injury.

Emerging Roles of Microglia Depletion in the Treatment of Spinal Cord Injury

Microglia, as the resident immune cells and first responder to neurological insults, play an extremely important role in the pathophysiological process of spinal cord injury. On the one hand, microglia respond rapidly and gather around the lesion in the early stage of injury to exert a protective role, but with the continuous stimulation of the injury, the excessive activated microglia secrete a large number of harmful substances, aggravate the injury of spinal cord tissue, and affect functional recovery. The effects of microglia depletion on the repair of spinal cord injury remain unclear, and there is no uniformly accepted paradigm for the removal methods and timing of microglia depletion, but different microglia depletion strategies greatly affect the outcomes after spinal cord injury. Therefore, this review summarizes the physiological and pathological roles of microglia, especially the effects of microglia depletion on spinal cord injury-sustained microglial depletion would aggravate injury and impair functional recovery, while the short-term depletion of microglial population in diseased conditions seems to improve tissue repair and promote functional improvement after spinal cord injury. Furthermore, we discuss the advantages and disadvantages of major strategies and timing of microglia depletion to provide potential strategy for the treatment of spinal cord injury.

Transcriptome-Wide N6-Methyladenosine Methylome Alteration in the Rat Spinal Cord After Acute Traumatic Spinal Cord Injury

Recent studies showed that RNA N6-methyladenosine (m6A) plays an important role in neurological diseases. We used methylated RNA immunoprecipitation sequencing (MeRIP-Seq) technology to generate the m6A modification map after traumatic spinal cord injury (TSCI). A total of 2,609 differential m6A peaks were identified after TSCI. Our RNA sequencing results after TSCI showed 4,206 genes with significantly altered expression. Cross-link analysis of m6A sequencing results and RNA sequencing results showed that 141 hyper-methylated genes were upregulated, 53 hyper-methylated genes were downregulated, 57 hypo-methylated genes were upregulated, and 197 hypo-methylated genes were downregulated. Among these, the important inflammatory response factor Tlr4 and the important member of the neurotrophin family Ngf were both upregulated and hyper-methylated after TSCI. This study provides that in the future, the epigenetic modifications of the genes could be used as an indicator of TSCI.

The Immunological Roles of Olfactory Ensheathing Cells in the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a devastating type of neurological disorder of the central nervous system (CNS) with high mortality and disability. The pathological processes of SCI can usually be described as two stages, namely, primary and acute secondary injuries. Secondary injury produces more significant exacerbations of the initial injury. Among all the mechanisms of secondary damage, infection and inflammatory responses, as the principle culprits in initiating the second phase of SCI, can greatly contribute to the severity of SCI and numerous sequelae after SCI. Therefore, effectively antagonizing pro-inflammatory responses may be a promising treatment strategy to facilitate functional recovery after SCI. Olfactory ensheathing cells (OECs), a unique type of glial cells, have increasingly become potential candidates for cell-based therapy in the injured CNS. Strikingly, there is growing evidence that the mechanisms underlying the anti-inflammatory role of OECs are associated with the immune properties and secretory functions of these cells responsible for anti-neuroinflammation and immunoregulatory effects, leading to maintenance of the internal microenvironment. Accordingly, a more profound understanding of the mechanism of OEC immunological functions in the treatment of SCI would be beneficial to improve the therapeutic clinical applications of OECs for SCI. In this review, we mainly summarize recent research on the cellular and molecular immune attributes of OECs. The unique biological functions of these cells in promoting neural regeneration are discussed in relation of the development of novel therapies for CNS injury.

Spinal Cord Injury and Loss of Cortical Inhibition

After spinal cord injury (SCI), the destruction of spinal parenchyma causes permanent deficits in motor functions, which correlates with the severity and location of the lesion. Despite being disconnected from their targets, most cortical motor neurons survive the acute phase of SCI, and these neurons can therefore be a resource for functional recovery, provided that they are properly reconnected and retuned to a physiological state. However, inappropriate re-integration of cortical neurons or aberrant activity of corticospinal networks may worsen the long-term outcomes of SCI. In this review, we revisit recent studies addressing the relation between cortical disinhibition and functional recovery after SCI. Evidence suggests that cortical disinhibition can be either beneficial or detrimental in a context-dependent manner. A careful examination of clinical data helps to resolve apparent paradoxes and explain the heterogeneity of treatment outcomes. Additionally, evidence gained from SCI animal models indicates probable mechanisms mediating cortical disinhibition. Understanding the mechanisms and dynamics of cortical disinhibition is a prerequisite to improve current interventions through targeted pharmacological and/or rehabilitative interventions following SCI.

Hippocampal Mitochondrial Abnormalities Induced the Dendritic Complexity Reduction and Cognitive Decline in a Rat Model of Spinal Cord Injury

Spinal cord injury (SCI) is a progressive neurodegenerative disease in addition to a traumatic event. Cognitive dysfunction following SCI has been widely reported in patients and animal models. However, the neuroanatomical changes affecting cognitive function after SCI, as well as the mechanisms behind these changes, have so far remained elusive. Herein, we found that SCI accelerates oxidative stress damage of hippocampal neuronal mitochondria. Then, for the first time, we presented a three-dimensional morphological atlas of rat hippocampal neurons generated using a fluorescence Micro-Optical Sectioning Tomography system, a method that accurately identifies the spatial localization of neurons and trace neurites. We showed that the number of dendritic branches and dendritic length was decreased in late stage of SCI. Western blot and transmission electron microscopy analyses also showed a decrease in synaptic communication. In addition, a battery of behavioral tests in these animals revealed hippocampal based cognitive dysfunction, which could be attributed to changes in the dendritic complexity of hippocampal neurons. Taken together, these results suggested that mitochondrial abnormalities in hippocampal neurons induced the dendritic complexity reduction and cognitive decline following SCI. Our study highlights the neuroanatomical basis and importance of mitochondria in brain degeneration following SCI, which might contribute to propose new therapeutic strategies.

How Does the Central Nervous System for Posture and Locomotion Cope With Damage-Induced Neural Asymmetry?

In most vertebrates, posture and locomotion are achieved by a biomechanical apparatus whose effectors are symmetrically positioned around the main body axis. Logically, motor commands to these effectors are intrinsically adapted to such anatomical symmetry, and the underlying sensory-motor neural networks are correspondingly arranged during central nervous system (CNS) development. However, many developmental and/or life accidents may alter such neural organization and acutely generate asymmetries in motor operation that are often at least partially compensated for over time. First, we briefly present the basic sensory-motor organization of posturo-locomotor networks in vertebrates. Next, we review some aspects of neural plasticity that is implemented in response to unilateral central injury or asymmetrical sensory deprivation in order to substantially restore symmetry in the control of posturo-locomotor functions. Data are finally discussed in the context of CNS structure-function relationship.

The role of electrical stimulation for rehabilitation and regeneration after spinal cord injury

Electrical stimulation is used to elicit muscle contraction and can be utilized for neurorehabilitation following spinal cord injury when paired with voluntary motor training. This technology is now an important therapeutic intervention that results in improvement in motor function in patients with spinal cord injuries. The purpose of this review is to summarize the various forms of electrical stimulation technology that exist and their applications. Furthermore, this paper addresses the potential future of the technology.

Antioxidative and Conductive Nanoparticles-Embedded Cell Niche for Neural Differentiation and Spinal Cord Injury Repair

Following spinal cord injury (SCI), the transmission of electrical signals is interrupted, and an oxidative microenvironment is generated, hindering nerve regeneration and functional recovery. The strategies of regulating oxidative pathological microenvironment while restoring endogenous electrical signal transmission hold promise for SCI treatment. However, challenges are still faced in simply fabricating bioactive scaffolds with both antioxidation and conductivity. Herein, aiming to construct an antioxidative and conductive microenvironment for nerve regeneration, the difunctional polypyrrole (PPy) nanoparticles were developed and incorporated into bioactive collagen/hyaluronan hydrogel. Owing to the embedded PPy in hydrogel, the encapsulated bone marrow mesenchymal stem cells (BMSCs) can be protected from oxidative damage, and their neuronal differentiation was promoted by the synergy between conductivity and electrical stimulation, which is proved to be related to PI3K/Akt and the mitogen-activated protein kinase (MAPK) pathway. In SCI rats, the BMSC-laden difunctional hydrogel restored the transmission of bioelectric signals and inhibited secondary damage, thereby facilitating neurogenesis, resulting in prominent nerve regeneration and functional recovery. Overall, taking advantage of a difunctional nanomaterial to meet two essential requirements in SCI repair, this work provides intriguing insights into the design of biomaterials for nerve regeneration and tissue engineering.