Delayed Paraparesis: An Unusual Complication Following Coarctation of Aorta Repair.

ABSTRACT: Paraparesis following cardiac surgery is a manifestation of spinal cord injury (SCI). It can occur in any aortic surgery from the aneurysm to the coarctation of the aorta (CoA) where the cross-clamp of the aorta is applied. Though the incidence of paraplegia is low, its occurrence affects the morbidity and mortality of the patient. There are only sporadic case reports on the development of paraplegia following recurrent and technically challenging repair of CoA. However, the spontaneous development of paraplegia has also been reported in cases of unoperated CoA. The present report describes the case of delayed SCI in which paraparesis developed 5 days post a coarctation repair. The risk factors and strategies to protect the spinal cord during aortic surgeries are emphasized.

Optimizing assessment of low frequency H-reflex depression in persons with spinal cord injury.

Considering the growing interest in clinical applications of neuromodulation, assessing effects of various modulatory approaches is increasingly important. Monosynaptic spinal reflexes undergo depression following repeated activation, offering a means to quantify neuromodulatory influences. Following spinal cord injury (SCI), changes in reflex modulation are associated with spasticity and impaired motor control. To assess disrupted reflex modulation, low-frequency depression (LFD) of Hoffman (H)-reflex excitability is examined, wherein the amplitudes of conditioned reflexes are compared to an unconditioned control reflex. Alternatively, some studies utilize paired-pulse depression (PPD) in place of the extended LFD train. While both protocols induce similar amounts of H-reflex depression in neurologically intact individuals, this may not be the case for persons with neuropathology. We compared the H-reflex depression elicited by PPD and by trains of 3-10 pulses to an 11-pulse LFD protocol in persons with incomplete SCI. The amount of depression produced by PPD was less than an 11-pulse train (mean difference = 0.137). When compared to the 11-pulse train, the 5-pulse train had a Pearson's correlation coefficient (R) of 0.905 and a coefficient of determination (R2) of 0.818. Therefore, a 5-pulse train for assessing LFD elicits modulation similar to the 11-pulse train and thus we recommend its use in lieu of longer trains.

Contribution of mechanoreceptors to spinal cord injury-induced mechanical allodynia.

ABSTRACT: Evidence from previous studies supports the concept that spinal cord injury (SCI)-induced neuropathic pain (NP) has its neural roots in the peripheral nervous system. There is uncertainty about how and to which degree mechanoreceptors contribute. Sensorimotor activation-based interventions (eg, treadmill training) have been shown to reduce NP after experimental SCI, suggesting transmission of pain-alleviating signals through mechanoreceptors. The aim of the present study was to understand the contribution of mechanoreceptors with respect to mechanical allodynia in a moderate mouse contusion SCI model. After genetic ablation of tropomyosin receptor kinase B expressing mechanoreceptors before SCI, mechanical allodynia was reduced. The identical genetic ablation after SCI did not yield any change in pain behavior. Peptidergic nociceptor sprouting into lamina III/IV below injury level as a consequence of SCI was not altered by either mechanoreceptor ablation. However, skin-nerve preparations of contusion SCI mice 7 days after injury yielded hyperexcitability in nociceptors, not in mechanoreceptors, which makes a substantial direct contribution of mechanoreceptors to NP maintenance unlikely. Complementing animal data, quantitative sensory testing in human SCI subjects indicated reduced mechanical pain thresholds, whereas the mechanical detection threshold was not altered. Taken together, early mechanoreceptor ablation modulates pain behavior, most likely through indirect mechanisms. Hyperexcitable nociceptors seem to be the main drivers of SCI-induced NP. Future studies need to focus on injury-derived factors triggering early-onset nociceptor hyperexcitability, which could serve as targets for more effective therapeutic interventions.

Combined rehabilitation therapy with botulinum toxin to the upper limbs for acute spinal cord injury: A case report.

INTRODUCTION: Patients with spinal cord injury (SCI) and incomplete paralysis may experience muscle immobilization due to functional impairment of agonist and antagonist muscles. This can induce spasticity and pain, with the risk of contracture increasing as the period of immobilization increases. This could be aggravated by pain, which interferes with rehabilitation. There is no established treatment for pain and joint contractures caused by acute SCI. Botulinum therapy plays a role in relieving muscle tension. Here, we report a case of acute SCI in which botulinum therapy was administered. CASE PRESENTATION: The patient experienced a C5-cervical SCI due to a road traffic accident, with marked paralysis in the upper and lower limbs below the C5 level. The patient had persistent elbow flexion since the SCI and complained of excruciating pain, making adequate rehabilitation difficult. Botulinum toxin was administered to the biceps and brachialis muscles 15 days after the SCI. After administration, the patient experienced a reduction in pain with relaxation of the elbow flexor muscles, and rehabilitation treatment was resumed. This patient's contracture did not worsen, his pain decreased, and he was able to initiate self-feeding training. DISCUSSION: In this case, occupational and physical therapy was administered with botulinum therapy. Together, they successfully reduced pain. Botulinum therapy provides analgesia and muscle relaxation and may lead to functional recovery, and we believe that treatment can be considered even in the acute phase.

Factors associated with symptomatic urinary tract infection in persons with spinal cord lesions who perform clean intermittent catheterization with single-use catheters.

OBJECTIVES: To investigate factors associated with symptomatic urinary tract infection (sUTI) in persons with chronic spinal cord lesion (SCL) who were using single-use catheters for intermittent self-catheterization (ISC). METHODS: Among respondents to an internet survey on the burden of illness on persons with SCL who were considered to be able to perform ISC, 111 persons using single-use catheters were included to examine factors associated with self-reported sUTI by univariate as well as multivariable analysis. RESULTS: The incidence of sUTI was significantly higher in males than in females (56.9% vs. 31.6%, p = .011), persons with stocks of antibiotics than those without it (82.9% vs. 28.6%, p < .011), and persons with more frequent bleeding during catheterization than those with less frequent bleeding (100% vs. 46.5%, p = .036). The incidence did not significantly differ between respective groups when various variables were evaluated by other characteristics of the participants, adherence to ISC procedures, and complications. On multivariable analysis, male gender and stocks of antibiotics were significant independent factors for sUTI. CONCLUSIONS: Male gender and stocks of antibiotics were associated with sUTI in persons with SCL who were performing ISC with single-use catheters.

ACOD1, rather than itaconate, facilitates p62-mediated activation of Nrf2 in microglia post spinal cord contusion.

BACKGROUND: Spinal cord injury (SCI)-induced neuroinflammation and oxidative stress (OS) are crucial events causing neurological dysfunction. Aconitate decarboxylase 1 (ACOD1) and its metabolite itaconate (Ita) inhibit inflammation and OS by promoting alkylation of Keap1 to induce Nrf2 expression; however, it is unclear whether there is another pathway regulating their effects in inflammation-activated microglia after SCI. METHODS: Adult male C57BL/6 ACOD1-/- mice and their wild-type (WT) littermates were subjected to a moderate thoracic spinal cord contusion. The degree of neuroinflammation and OS in the injured spinal cord were assessed using qPCR, western blot, flow cytometry, immunofluorescence, and trans-well assay. We then employed immunoprecipitation-western blot, chromatin immunoprecipitation (ChIP)-PCR, dual-luciferase assay, and immunofluorescence-confocal imaging to examine the molecular mechanisms of ACOD1. Finally, the locomotor function was evaluated with the Basso Mouse Scale and footprint assay. RESULTS: Both in vitro and in vivo, microglia with transcriptional blockage of ACOD1 exhibited more severe levels of neuroinflammation and OS, in which the expression of p62/Keap1/Nrf2 was down-regulated. Furthermore, silencing ACOD1 exacerbated neurological dysfunction in SCI mice. Administration of exogenous Ita or 4-octyl itaconate reduced p62 phosphorylation. Besides, ACOD1 was capable of interacting with phosphorylated p62 to enhance Nrf2 activation, which in turn further promoted transcription of ACOD1. CONCLUSIONS: Here, we identified an unreported ACOD1-p62-Nrf2-ACOD1 feedback loop exerting anti-inflammatory and anti-OS in inflammatory microglia, and demonstrated the neuroprotective role of ACOD1 after SCI, which was different from that of endogenous and exogenous Ita. The present study extends the functions of ACOD1 and uncovers marked property differences between endogenous and exogenous Ita. KEY POINTS: ACOD1 attenuated neuroinflammation and oxidative stress after spinal cord injury. ACOD1, not itaconate, interacted with p-p62 to facilitate Nrf2 expression and nuclear translocation. Nrf2 was capable of promoting ACOD1 transcription in microglia.

Facilitation of neurological recovery in a complete spinal cord injury with NeuroAiD: case report.

INTRODUCTION: NeuroAiD (MLC601 & MLC901)'s neuroprotective capabilities include limiting exaggerated calcium influx, decreasing excitotoxicity, reducing oxidative stress, and preventing glutamate-induced cell death. It has also been shown to facilitate synaptogenesis, neurogenesis, and neuroplasticity. However, its clinical efficacy has primarily been studied in the context of brain injuries, particularly stroke. NeuroAiD's potential application in SCI remains largely untapped. CASE PRESENTATION: A 34-year-old male presented with C4 complete tetraplegia. Following surgical decompression and initial inpatient rehabilitation, he started consuming MLC901 two capsules three times daily at month 4 post injury for 6 months. He regained considerable neurological recovery following the supplementation. Apart from the improvement in the neurological level of injury, the patient exhibited motor recovery beyond the initial zone of partial preservation up to 24 months post injury. DISCUSSION: Our findings align with a recent animal study demonstrating MLC901's potential to downregulate Vascular Endothelial Growth Factor (VEGF), a molecule known to increase vascular permeability and exacerbate tissue edema and infarction. In another animal study involving stroke-affected mice, MLC901 demonstrates the ability to promote neurological recovery by regulating the expression of proteins mediating angiogenesis, such as hypoxic inducible factor 1α, erythropoietin, angiopoietins 1 and 2, as well as VEGF. The anecdotal findings from this case report offer preliminary insights into NeuroAiD's potential in facilitating recovery during post-acute and chronic phases of severe SCI, necessitating further exploration.

Prediction model for spinal cord injury in spinal tuberculosis patients using multiple machine learning algorithms: a multicentric study.

Spinal cord injury (SCI) is a prevalent and serious complication among patients with spinal tuberculosis (STB) that can lead to motor and sensory impairment and potentially paraplegia. This research aims to identify factors associated with SCI in STB patients and to develop a clinically significant predictive model. Clinical data from STB patients at a single hospital were collected and divided into training and validation sets. Univariate analysis was employed to screen clinical indicators in the training set. Multiple machine learning (ML) algorithms were utilized to establish predictive models. Model performance was evaluated and compared using receiver operating characteristic (ROC) curves, area under the curve (AUC), calibration curve analysis, decision curve analysis (DCA), and precision-recall (PR) curves. The optimal model was determined, and a prospective cohort from two other hospitals served as a testing set to assess its accuracy. Model interpretation and variable importance ranking were conducted using the DALEX R package. The model was deployed on the web by using the Shiny app. Ten clinical characteristics were utilized for the model. The random forest (RF) model emerged as the optimal choice based on the AUC, PRs, calibration curve analysis, and DCA, achieving a test set AUC of 0.816. Additionally, MONO was identified as the primary predictor of SCI in STB patients through variable importance ranking. The RF predictive model provides an efficient and swift approach for predicting SCI in STB patients.

Intrathecal delivery of adipose-derived mesenchymal stem cells in traumatic spinal cord injury: Phase I trial.

Intrathecal delivery of autologous culture-expanded adipose tissue-derived mesenchymal stem cells (AD-MSC) could be utilized to treat traumatic spinal cord injury (SCI). This Phase I trial (ClinicalTrials.gov: NCT03308565) included 10 patients with American Spinal Injury Association Impairment Scale (AIS) grade A or B at the time of injury. The study's primary outcome was the safety profile, as captured by the nature and frequency of adverse events. Secondary outcomes included changes in sensory and motor scores, imaging, cerebrospinal fluid markers, and somatosensory evoked potentials. The manufacturing and delivery of the regimen were successful for all patients. The most commonly reported adverse events were headache and musculoskeletal pain, observed in 8 patients. No serious AEs were observed. At final follow-up, seven patients demonstrated improvement in AIS grade from the time of injection. In conclusion, the study met the primary endpoint, demonstrating that AD-MSC harvesting and administration were well-tolerated in patients with traumatic SCI.

Pressure ulcers acquired during inpatient rehabilitation after spinal cord injury, characterization and predictors: A 15-years' experience.

BACKGROUND: Most studies focus on the risk factors associated with the development of pressure ulcers (PUs) during acute phase or community care for individuals with spinal cord injury (SCI). OBJECTIVES: This study aimed to i) compare clinical and demographic characteristics of inpatients after SCI with PUs acquired during rehabilitation vs inpatients without PUs and ii) evaluate an existing PU risk assessment tool iii) identify first PU predictors. METHODS: Individuals (n = 1,135) admitted between 2008 and 2022 to a rehabilitation institution within 60 days after SCI were included. Admission Functional Independence Measure (FIM), American Spinal Injury Association Impairment Scale (AIS) and mEntal state, Mobility, Incontinence, Nutrition, Activity (EMINA) were assessed. Kaplan-Meier curves and Cox proportional hazards models were fitted. RESULTS: Overall incidence of PUs was 8.9%. Of these, 40.6% occurred in the first 30 days, 47.5% were sacral, 66.3% were Stage II. Patients with PUs were older, mostly with traumatic injuries (67.3%), AIS A (54.5%), lower FIM motor (mFIM) score and mechanical ventilation. We identified specific mFIM items to increase EMINA specificity. Adjusted Cox model yielded sex (male), age at injury, AIS grade, mFIM and diabetes as PUs predictors (C-Index = 0.749). CONCLUSION: Inpatients can benefit from combined assessments (EMINA + mFIM) and clinical features scarcely addressed in previous studies to prevent PUs.

Integrating Patient Preferences with Guideline-Based Care in Neurogenic Lower Urinary Tract Dysfunction After Spinal Cord Injury.

Individual and social factors are important for clinical decision-making in patients with neurogenic bladder secondary to spinal cord injury (SCI). These factors include the availability of caregivers, social infrastructure, and personal preferences, which all can drive bladder management decisions. These elements can be overlooked in clinical decision-making; therefore, there is a need to elicit and prioritize patient preferences and values into neurogenic bladder care to facilitate personalized bladder management choices. For the purposes of this article, we review the role of guideline-based care and shared decision-making in the SCI population with neurogenic lower urinary tract dysfunction.

A portable system to measure knee extensor spasticity after spinal cord injury.

BACKGROUND: The pendulum test is a quantitative method used to assess knee extensor spasticity in humans with spinal cord injury (SCI). Yet, the clinical implementation of this method remains limited. The goal of our study was to develop an objective and portable system to assess knee extensor spasticity during the pendulum test using inertial measurement units (IMU). METHODS: Spasticity was quantified by measuring the first swing angle (FSA) using a 3-dimensional optical tracking system (with external markers over the iliotibial band, lateral knee epicondyle, and lateral malleolus) and two wireless IMUs (positioned over the iliotibial band and mid-part of the lower leg) as well as a clinical exam (Modified Ashworth Scale, MAS). RESULTS: Measurements were taken on separate days to assess test-retest reliability and device agreement in humans with and without SCI. We found no differences between FSA values obtained with the optical tracking system and the IMU-based system in control subjects and individuals with SCI. FSA values from the IMU-based system showed excellent agreement with the optical tracking system in individuals with SCI (ICC > 0.98) and good agreement in controls (ICC > 0.82), excellent test-retest reliability across days in SCI (ICC = 0.93) and good in controls (ICC = 0.87). Notably, FSA values measured by both systems showed a strong association with MAS scores ( ρ  ~ -0.8) being decreased in individuals with SCI with higher MAS scores, reflecting the presence of spasticity. CONCLUSIONS: These findings suggest that our new portable IMU-based system provides a robust and flexible alternative to a camera-based optical tracking system to quantify knee extensor spasticity following SCI.

A case report of three people experiencing intractable autonomic dysreflexia following instillation of Uro-Tainer® Polyhexanide 0.02.

INTRODUCTION: Historically, bladder washouts were used to instil therapeutic reagents directly into the bladder. This practice has expanded to include instillation of solutions that deal with catheter issues such as encrustation or formation of bio-film. They appear to provide a promising strategy for people with long term catheters. These products are readily available to purchase, but there is concern that people are using these solutions without a complete understanding of the purpose for the rinse and without clinical guidance to monitor response to treatment. CASE PRESENTATION: These case studies include three people living with spinal cord injury (SCI) who developed severe autonomic dysreflexia (AD) when a catheter rinse was carried out using a particular solution. Each of the cases developed immediate and, in some cases, intractable AD requiring further intervention to resolve symptoms. DISCUSSION: Catheter-associated urinary tract infection is a significant cause of morbidity and mortality in people living with SCI. Long-term catheters provide a vector for opportunistic micro-organisms to form bio-film and create an environment that promotes formation of struvite calculi, thus increasing the risk of chronic catheter blockage and urinary tract infection. Whilst these solutions are used to reduce these risks, they also pose additional risks to people susceptible to AD. These cases highlight the need for judicious patient selection and clinical oversight and management of adverse events when using catheter rinse solutions in certain people living with SCI. This is supported by a decision-making algorithm and a response to AD algorithm. This case report was prepared following the CARE Guidelines (supplementary file 1).

Urinary Tract Infection Diagnostic and Management Considerations in People with Spinal Cord Injury and Neurogenic Bladder.

Urinary tract infections (UTIs) are common complications in people with neurogenic bladder. Prevention, diagnosis, and treatment are challenging for several reasons, including a high prevalence of asymptomatic bacteriuria and catheter use, frequent ambiguous nonlocalizing signs and symptoms, increased risk for complications and difficult-to-treat pathogens, and a lack of effective preventative methods. Current research aims to improve elicitation and evaluation of signs and symptoms, implement algorithms to avoid urine cultures in asymptomatic patients and use appropriate antibiotics for UTI, and identify novel effective prevention methods.

ATF3 is a neuron-specific biomarker for spinal cord injury and ischaemic stroke.

BACKGROUND: Although many molecules have been investigated as biomarkers for spinal cord injury (SCI) or ischemic stroke, none of them are specifically induced in central nervous system (CNS) neurons following injuries with low baseline expression. However, neuronal injury constitutes a major pathology associated with SCI or stroke and strongly correlates with neurological outcomes. Biomarkers characterized by low baseline expression and specific induction in neurons post-injury are likely to better correlate with injury severity and recovery, demonstrating higher sensitivity and specificity for CNS injuries compared to non-neuronal markers or pan-neuronal markers with constitutive expressions. METHODS: In animal studies, young adult wildtype and global Atf3 knockout mice underwent unilateral cervical 5 (C5) SCI or permanent distal middle cerebral artery occlusion (pMCAO). Gene expression was assessed using RNA-sequencing and qRT-PCR, while protein expression was detected through immunostaining. Serum ATF3 levels in animal models and clinical human samples were measured using commercially available enzyme-linked immune-sorbent assay (ELISA) kits. RESULTS: Activating transcription factor 3 (ATF3), a molecular marker for injured dorsal root ganglion sensory neurons in the peripheral nervous system, was not expressed in spinal cord or cortex of naïve mice but was induced specifically in neurons of the spinal cord or cortex within 1 day after SCI or ischemic stroke, respectively. Additionally, ATF3 protein levels in mouse blood significantly increased 1 day after SCI or ischemic stroke. Importantly, ATF3 protein levels in human serum were elevated in clinical patients within 24 hours after SCI or ischemic stroke. Moreover, Atf3 knockout mice, compared to the wildtype mice, exhibited worse neurological outcomes and larger damage regions after SCI or ischemic stroke, indicating that ATF3 has a neuroprotective function. CONCLUSIONS: ATF3 is an easily measurable, neuron-specific biomarker for clinical SCI and ischemic stroke, with neuroprotective properties. HIGHLIGHTS: ATF3 was induced specifically in neurons of the spinal cord or cortex within 1 day after SCI or ischemic stroke, respectively. Serum ATF3 protein levels are elevated in clinical patients within 24 hours after SCI or ischemic stroke. ATF3 exhibits neuroprotective properties, as evidenced by the worse neurological outcomes and larger damage regions observed in Atf3 knockout mice compared to wildtype mice following SCI or ischemic stroke.

Bilateral tibial fractures associated with powered exoskeleton use in complete spinal cord injury - a case report & literature review.

INTRODUCTION: Powered robotic exoskeleton (PRE) physiotherapy programmes are a relatively novel frontier which allow patients with reduced mobility to engage in supported walking. Research is ongoing regarding their utility, risks, and benefits. This article describes the case of two fractures occurring in one patient using a PRE. CASE: We report the case of a 54 year old man who sustained bilateral tibial fractures while using a PRE, on a background of T10 AIS A SCI. The initial session was discontinued due to acute severe bilateral knee swelling after approximately 15 min. The patient attended their local hospital the following day, where radiographs demonstrated bilateral proximal tibial fractures. The patient was treated with manipulation under anaesthetic and long-leg casting for five weeks, at which point he was stepped down to hinged knee braces which were weaned gradually while he remained non-weight bearing for 12 weeks. The patient was investigated with DEXA scan and was diagnosed with osteoporosis. He was liaised with rheumatology services and bone protection was initiated. Fracture healing was achieved and weight-bearing precautions were discontinued, however this period of immobilisation led to significant spasticity. The patient was discharged from orthopaedic services, with ongoing rehabilitation and physiotherapy follow-up. CONCLUSION: PRE assisted physiotherapy programmes are a promising concept in terms of rehabilitation and independence, however they are not without risk and it is important that both providers and patients are aware of this. Furthermore, SCI patients are at increased risk for osteoporosis and should be monitored and considered for bone protection.

Priorities, needs and willingness of use of nerve stimulation devices for bladder and bowel function in people with spinal cord injury (SCI): an Australian survey.

STUDY DESIGN: Anonymous online survey OBJECTIVES: To investigate the priorities, needs and willingness to adopt nerve stimulation devices for managing neurogenic bladder and bowel function in people with spinal cord injury (SCI) living in Australia. SETTING: Online survey of people living with SCI in Australia. METHODS: This anonymous online survey used Qualtrics and was advertised via standard communication channels, such as advocacy groups representing the SCI community in Australia, social media, attending SCI sporting events and by word-of-mouth. RESULTS: Responses from 62 individuals (32% female, 68% male) were included. Bladder emptying through urethra without catheter was the highest priority for bladder function. Reducing time required for bowel routines and constipation were the top priorities regarding bowel function. The highest concern for internal/implanted devices was the 4% chance of device surgical removal, while wearing wires under the clothes was the main concern for external devices. 53% of respondents were willing to trial an implanted nerve stimulation device, while 70% would trial an external device to improve and gain independence in bladder and bowel function. CONCLUSION: The findings of this study highlighted the potential role in which nerve stimulation can have in addressing bladder and bowel dysfunction in people with SCI, and have also identified that there was a need for Australian physiotherapists to evaluate their role in bladder and bowel dysfunction. Results from this study can help guide further research in nerve stimulation devices for bladder and bowel dysfunction in people with SCI. SPONSORSHIP: n/a.

Fisetin orchestrates neuroinflammation resolution and facilitates spinal cord injury recovery through enhanced autophagy in pro-inflammatory glial cells.

BACKGROUND: Neuroinflammation, a critical component of the secondary injury cascade post-spinal cord injury, involves the activation of pro-inflammatory cells and release of inflammatory mediators. Resolution of neuroinflammation is closely linked to cellular autophagy. This study investigates the potential of Fisetin, a natural anti-inflammatory compound, to ameliorate neuroinflammation and confer spinal cord injury protection through the regulation of autophagy in pro-inflammatory cells. METHODS: Utilizing a rat T10 spinal cord injury model with distinct treatment groups (Sham, Fisetin-treated, and Fisetin combined with autophagy inhibitor), alongside in vitro models involving lipopolysaccharide (LPS)-stimulated microglial cell activation and co-culture with neurons, we employed techniques such as transcriptomic sequencing, histological assessments (immunofluorescence staining, etc.), molecular analyses (PCR, WB, ELISA, etc.), and behavioral evaluations to discern differences in neuroinflammation, autophagy, neuronal apoptosis, and neurological function recovery. RESULTS: Fisetin significantly augmented autophagic activity in injured spinal cord tissue, crucially contributing to neurological function recovery in spinal cord-injured rats. Fisetin's autophagy-dependent effects were associated with a reduction in neuronal apoptosis at the injury site. The treatment reduced the population of CD68+ and iNOS+ cells, coupled with decreased pro-inflammatory cytokines IL-6 and TNF-α levels, through autophagy-dependent pathways. Fisetin pre-treatment attenuated LPS-induced pro-inflammatory polarization of microglial cells, with this protective effect partially blocked by autophagy inhibition. Fisetin-induced autophagy in the injured spinal cord and pro-inflammatory microglial cells was associated with significant activation of AMPK and inhibition of mTOR. CONCLUSION: Fisetin orchestrates enhanced autophagy in pro-inflammatory microglial cells through the AMPK-mTOR signaling pathway, thereby mitigating neuroinflammation and reducing the apoptotic effects of neuroinflammation on neurons. This mechanistic insight significantly contributes to the protection and recovery of neurological function following spinal cord injury, underscoring the vital nature of Fisetin as a potential therapeutic agent.

Multi-session transcutaneous spinal cord stimulation prevents chloride homeostasis imbalance and the development of hyperreflexia after spinal cord injury in rat.

Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.