Thoracic Spinal Cord Injury Research Articles

Evolution of Real-World Clinical Practice in Time to Surgery Following Thoracolumbar Spinal Cord Injury: An Observational Study of North American Trauma Centers from 2010 to 2020.

This study aims to estimate real-world clinical practice trends in time to surgery following thoracolumbar spinal cord injury (SCI) in trauma centers across North America over the last decade (2010-2020). A multi-center retrospective observational study was conducted using Trauma Quality Improvement Program data from 2010 to 2020. All surgically treated patients with thoracic and lumbar SCI were included. Descriptive plots and a multivariable Poisson regression model with time to spine surgery as the primary outcome were constructed. This study included 4350 adult patients with complete SCI surgically treated across 449 trauma centers. Within this group, 3978 (91.4%) patients were diagnosed with thoracic SCI and 372 (8.6%) patients were diagnosed with lumbar SCI. The overall mean time to surgery was 31.6 h (±34.1). Early surgery (≤24 h) was performed in 2599 patients (59.7%). An estimated annual reduction of 1.6 h in time to surgery was demonstrated over the study period, starting initially at a mean of 47.6 h (±40.6) in 2010, and reaching a mean of 25.3 h (±30) in 2020. Multivariable Poisson regression adjusting for patient, injury, and institution confounders, demonstrated a significant decrease in time to surgery by 5% per year over the study period (incidence rate ratios [IRR] = 0.95, 95% confidence interval [CI]: 0.93-0.96). Moreover, in a secondary analysis including 3270 patients with incomplete thoracolumbar SCI, a comparable significant annual reduction in time to surgery was demonstrated (IRR = 0.93, 95% CI: 0.91-0.94). This study provides real-world data on practice pattern trends with respect to time to spine surgery following traumatic thoracolumbar SCI. Over the years from 2010 to 2020, we found a significant reduction in time to surgery across trauma centers in North America.

Neurotrophic and synaptic effects of GnRH and/or GH upon motor function after spinal cord injury in rats

Thoracic spinal cord injury (SCI) profoundly impairs motor and sensory functions, significantly reducing life quality without currently available effective treatments for neuroprotection or full functional regeneration. This study investigated the neurotrophic and synaptic recovery potential of gonadotropin-releasing hormone (GnRH) and growth hormone (GH) treatments in ovariectomized rats subjected to thoracic SCI. Employing a multidisciplinary approach, we evaluated the effects of these hormones upon gene expression of classical neurotrophins (NGF, BDNF, and NT3) as well as indicative markers of synaptic function (Nlgn1, Nxn1, SNAP25, SYP, and syntaxin-1), together with morphological assessments of myelin sheath integrity (Klüver-Barrera staining and MBP immunoreactivity) and synaptogenic proteins (PSD95, SYP) by immunohystochemistry (IHC) , and also on the neuromotor functional recovery of hindlimbs in the lesioned animals. Results demonstrated that chronic administration of GnRH and GH induced notable upregulation in the expression of several neurotrophic and synaptogenic activity genes. Additionally, the treatment showed a significant impact on the restoration of functional synaptic markers and myelin integrity. Intriguingly, while individual GnRH application induced certain recovery benefits, the combined treatment with GH appeared to inhibit neuromotor recovery, suggesting a complex interplay in hormonal regulation post-SCI. GnRH and GH are bioactive and participate in modulating neurotrophic responses and synaptic restoration under neural damage conditions, offering insights into novel therapeutic approaches for SCI. However, the intricate effects of combined hormonal treatment accentuate the necessity for further investigation that conduce to optimal and novel therapeutic strategies for patients with spinal cord lesions.

Clinical risk factors associated with the need for tracheostomy in traumatic cervical and high thoracic spinal cord injury

BackgroundOur objective was to assess the association of completeness and level of spinal cord injury (SCI) with the need for tracheostomy and identify additional risk factors predictive of tracheostomy. MethodsThis was a retrospective review of patients with SCI between January 2017 and December 2022. ResultsPatients with complete SCI were roughly thirty-three times more likely to have a tracheostomy when compared to incomplete injury (82 ​% vs 12 ​%, p ​< ​0.001, OR ​= ​32.9). The rate of tracheostomy did not differ between spinal cord levels for complete (p ​= ​0.68) or incomplete (p ​= ​0.08) injuries. Penetrating injury, low GCS, high ISS, and polytrauma were associated with tracheostomy need in incomplete SCI. ConclusionComplete injury was statistically significantly associated with the need for tracheostomy while level of injury failed to reach significance. Patients with incomplete SCI that have certain clinical risk factors should be considered for early tracheostomy.

Cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injuries

Objectives To examine cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injury (SCI) compared with the general population, and explore if the neurological level of injury (NLI) is related to cardiovascular autonomic function. Design Population-based cross-sectional study with matched controls. Setting Outpatient SCI unit in Southern Sweden. Participants Twenty-five individuals (20% women, mean age 58 years and mean time since injury 28 years, NLI C2-T6, American Spinal Injury Association Impairment Scale A-C) from the Swedish SPinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment (SPICA). Matched controls were obtained from the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) at a ratio of 5:1. Interventions Not applicable. Outcome measures 24 h electrocardiography and deep breathing tests. 24 h ambulatory blood pressure (BP) monitoring and orthostatic BP tests. Results In individuals with SCI compared with controls, heart rate variability (24h mean SD of the normal-to-normal interval 112 ms vs 145 ms, P < 0.001) and diastolic orthostatic BP increase (2.0 and 9.4 mmHg, P < 0.001), were significantly lower, whereas BP variability was significantly higher (24h mean systolic SDBP 17.8 mmHg vs 15.7 mmHg, P = 0.029). Circadian patterns of heart rate variability and BP (lack of nocturnal dip) were significantly different among the individuals with SCI than controls. Higher NLI was significantly (P < 0.05) correlated with impairments to various cardiovascular autonomic function variables. Conclusions This exploratory study indicates that cardiovascular autonomic function is impaired in middle-aged people with long-term cervical and upper thoracic SCI compared with the general non-SCI population, and more pronounced with a higher NLI. Future research is needed to understand the pathophysiological mechanisms underlying these impairments, and the prognostic significance for individuals with SCI. Trial registration ClinicalTrials.gov identifier: NCT03515122.

Acute Implantation of a Bioresorbable Polymer Scaffold in Patients With Complete Thoracic Spinal Cord Injury: A Randomized Controlled Trial (INSPIRE 2.0).

Traumatic spinal cord injury (SCI) remains a devastating condition with no proven effective treatment options available. In a prior single-arm study of patients with thoracic complete SCI (INSPIRE; ClinicalTrials.gov, NCT02138110), acute implantation of an investigational bioresorbable polymer scaffold (Neuro-Spinal Scaffold [NSS]) appeared to be safe through 24 months postimplantation and was associated with an American Spinal Injury Association Impairment Scale (AIS) conversion rate that exceeded historical controls. Here, we evaluated whether NSS implantation demonstrates probable benefit for safety and neurological recovery in patients with thoracic complete SCI vs standard-of-care spine surgery. INSPIRE 2.0 was a randomized, controlled, parallel, multicenter study conducted at Level I trauma centers in the United States (ClinicalTrials.gov, NCT03762655; funded by InVivo Therapeutics Corporation). Patients with AIS grade A, thoracic (T2-T12), nonpenetrating SCI requiring spine surgery ≤7 days postinjury were randomized (1:1, computer-generated allocation) to undergo NSS implantation or spine surgery alone (control group). Patients and follow-up International Standards for Neurological Classification of SCI assessors were blinded. A predefined study success criterion required the proportion of patients with improvement of ≥1 AIS grade at 6 months postsurgery (primary endpoint) to be ≥20% higher in the NSS group than in the control group. Target enrollment was reached (N = 20) with 10 patients randomized and analyzed in each group. At 6 months postsurgery, an improvement in the AIS grade was reported in 2 NSS patients (20%; both to AIS C) and 3 control group patients (30%; to AIS B [n = 2] or AIS C [n = 1]). No serious or unanticipated adverse device effects were reported. The study was closed to further follow-up because of not meeting its primary endpoint. In this small group of patients with thoracic complete (AIS A) SCI, implantation of an intraparenchymal bioresorbable scaffold did not produce probable clinical benefit. However, this study provides evidence that surgical intervention in an injured spinal cord parenchyma may be performed safely.

Changes in intra- and interlimb reflexes from forelimb cutaneous afferents after staggered thoracic lateral hemisections during locomotion in cats.

In quadrupeds, such as cats, cutaneous afferents from the forepaw dorsum signal external perturbations and send inputs to spinal circuits to co-ordinate the activity in muscles of all four limbs. How these cutaneous reflex pathways from forelimb afferents are reorganized after an incomplete spinal cord injury is not clear. Using a staggered thoracic lateral hemisections paradigm, we investigated changes in intralimb and interlimb reflex pathways by electrically stimulating the left and right superficial radial nerves in seven adult cats and recording reflex responses in five forelimb and ten hindlimb muscles. After the first (right T5-T6) and second (left T10-T11) hemisections, forelimb-hindlimb co-ordination was altered and weakened. After the second hemisection, cats required balance assistance to perform quadrupedal locomotion. Short-, mid- and long-latency homonymous and crossed reflex responses in forelimb muscles and their phase modulation remained largely unaffected after staggered hemisections. The occurrence of homolateral and diagonal mid- and long-latency responses in hindlimb muscles evoked with left and right superficial radial nerve stimulation was significantly reduced at the first time point after the first hemisection, but partially recovered at the second time point with left superficial radial nerve stimulation. These responses were lost or reduced after the second hemisection. When present, all reflex responses, including homolateral and diagonal, maintained their phase-dependent modulation. Therefore, our results show a considerable loss in cutaneous reflex transmission from cervical to lumbar levels after incomplete spinal cord injury, albeit with preservation of phase modulation, probably affecting functional responses to external perturbations. KEY POINTS: Cutaneous afferent inputs co-ordinate muscle activity in the four limbs during locomotion when the forepaw dorsum contacts an obstacle. Thoracic spinal cord injury disrupts communication between spinal locomotor centres located at cervical and lumbar levels, impairing balance and limb co-ordination. We investigated cutaneous reflexes from forelimb afferents during quadrupedal locomotion by electrically stimulating the superficial radial nerve bilaterally, before and after staggered lateral thoracic hemisections in cats. We showed a loss/reduction of mid- and long-latency homolateral and diagonal reflex responses in hindlimb muscles early after the first hemisection that partially recovered with left superficial radial nerve stimulation, before being reduced after the second hemisection. Targeting cutaneous reflex pathways from forelimb afferents projecting to the four limbs could help develop therapeutic approaches aimed at restoring transmission in ascending and descending spinal pathways.

Enhancing upper extremity muscle strength in individuals with spinal cord injury using low-intensity blood flow restriction exercise.

This study explores the feasibility and effects of low-intensity blood flow restriction exercise on forearm muscle strength and function in individuals with spinal cord injury. Pilot randomized clinical trial. Ten male and female adult participants with chronic cervical and thoracic spinal cord injury underwent an 8-week low-intensity blood flow restriction exercise programme that targeted forearm muscles. Each participant's contralateral forearm served as the control. Grip strength was the primary outcome measure, and participants also provided qualitative feedback on their experiences. The study revealed a significant increase in participants' forearm muscle strength on the experimental side engaged in low-intensity blood flow restriction training, with an average strength gain of 7.5 ± 0.36 kg after 16 exercise sessions (Cohen's d = -6.32, 95% CI -8.34, -6.68). In comparison, the control side, following a conventional high- intensity exercise regimen without BFR, showed a more modest strength increase of 4.4 ± 0.67 kg. A mean Patient's Global Impression of Change score of 2.2 reflected overall improvements in participants' daily activities and health status. This study highlights the feasibility and effectiveness of low-intensity blood flow restriction exercise as a safe and promising approach to enhancing forearm muscle strength in individuals with spinal cord injury. The observed positive outcomes, coupled with a high level of participant satisfaction, underscore the potential of this innovative method to significantly improve limb muscle strength, thereby contributing to greater functional independence in this population.

Quantifying Treatments as Usual and with Technologies in Neurorehabilitation of Individuals with Spinal Cord Injury.

Several technologies have been introduced into neurorehabilitation programs to enhance traditional treatment of individuals with Spinal Cord Injury (SCI). Their effectiveness has been widely investigated, but their adoption has not been properly quantified. The aim of this study is to assess the distribution of conventional (Treatment As Usual-TAU) and technology-aided (Treatment With Technologies-TWT) treatments conveniently grouped based on different therapeutic goals in a selected SCI unit. Data from 104 individuals collected in 29 months were collected in a custom database and categorized according to both the conventional American Impairment Scale classification and a newly developed Multifactor (MF) clustering approach that considers additional sources of information (the lesion level, the level of independence in the activities of daily living, and the hospitalization duration). Results indicated an average technology adoption of about 30%. Moreover, the MF clusters were less overlapped, and the differences in TWT adoption were more pronounced than in AIS-based clustering. MF clustering was capable of grouping individuals based both on neurological features and functional abilities. In particular, individuals with motor complete injuries were grouped together, whereas individuals with sensorimotor incomplete SCI were collected separately based on the lesion level. As regards TWT adoption, we found that in the case of motor complete SCI, TWT for muscle tone control and modulation was mainly selected (about 90% of TWT), while the other types of TWT were seldom adopted. Even for individuals with incomplete SCI, the most frequent rehabilitation goal was muscle tone modulation (about 75% of TWT), regardless of the AIS level, and technologies to improve walking ability (about 12% of TWT) and balance control (about 10% of TWT) were mainly used for individuals with thoracic or lumbar lesions. Analyzing TAU distribution, we found that the highest adoption of muscle tone modulation strategies was reported in the case of individuals with motor complete SCI (about 42% of TAU), that is, in cases when almost no gait training was pursued (about 1% of TAU). In the case of cervical motor incomplete SCI, compared to thoracic and lumbar incomplete SCI, there was a greater focus on muscle tone control and force recruitment in addition to walking training (38% and 14% of TAU, respectively) than on balance training. Overall, the MF clustering provided more insights than the traditional AIS-based classification, highlighting differences in TWT adoption. These findings suggest that a wider overview that considers both neurological and functional characteristics of individuals after SCI based on a multifactor analysis could enhance the personalization of neurorehabilitation strategies.

Spinal Cord Injury Enhances Lung Inflammation and Exacerbates Immune Response After Acute Lung Injury.

The severity of spinal cord injury (SCI) is closely tied to pulmonary function, especially in cases of higher SCI levels. Despite this connection, the underlying pathological mechanisms in the lungs post-SCI are not well understood. Previous research has established a connection between disrupted sympathetic regulation and splenocyte apoptosis in high thoracic SCI, leading to pulmonary dysfunction. The aim of this study was to investigate whether mice with low-level SCI exhibit increased susceptibility to acute lung injury by eliciting systemic inflammatory responses that operate independently of the sympathetic nervous system. Here, we employed T9 contusion SCI and exposed mice to aerosolized lipopolysaccharide (LPS) to simulate lung inflammation associated with acute respiratory distress syndrome (ARDS). Twenty-four hours post-LPS exposure, lung tissues and bronchoalveolar lavage (BAL) fluid were analyzed. LPS markedly induced proinflammatory gene expression (SAA3, IRG1, NLRP3, IL-1beta, MCP-1) and cytokine release (IL-1beta, IL-6, MCP-1) in SCI mice compared to controls, indicating an exaggerated inflammatory response. Infiltration of Ly6G/C positive neutrophils and macrophages was significantly higher in SCI mice lungs post-LPS exposure. Interestingly, spleen size and weight did not differ between control and SCI mice, suggesting that T9 SCI alone does not cause spleen atrophy. Notably, bone-marrow-derived macrophages (BMDMs) from SCI mice exhibited hyper-responsiveness to LPS. This study demonstrated an increase in lung inflammation and immune responses subsequent to low-level T9 SCI, underscoring the widespread influence of systemic inflammation post-SCI, especially pronounced in specific organs like the lungs.

Intraspinal microstimulation of the ventral horn has therapeutically relevant cross-modal effects on nociception.

Electrical stimulation of spinal networks below a spinal cord injury is a promising approach to restore functions compromised by inadequate and/or inappropriate neural drive. The most translationally successful examples are paradigms intended to increase neural transmission in weakened yet spared descending motor pathways and spinal motoneurons rendered dormant after being severed from their inputs by lesion. Less well understood is whether spinal stimulation is also capable of reducing neural transmission in pathways made pathologically overactive by spinal cord injury. Debilitating spasms, spasticity and neuropathic pain are all common manifestations of hyperexcitable spinal responses to sensory feedback. Whereas spasms and spasticity can often be managed pharmacologically, spinal cord injury-related neuropathic pain is notoriously medically refractory. Interestingly, however, spinal stimulation is a clinically available option for ameliorating neuropathic pain arising from aetiologies other than spinal cord injury, and the limited evidence available to date suggests that it holds considerable promise for reducing spinal cord injury-related neuropathic pain, as well. Spinal stimulation for pain amelioration has traditionally been assumed to modulate sensorimotor networks overlapping with those engaged by spinal stimulation for rehabilitation of movement impairments. Thus, we hypothesize that spinal stimulation intended to increase the ability to move voluntarily may simultaneously reduce transmission in spinal pain pathways. To test this hypothesis, we coupled a rat model of incomplete thoracic spinal cord injury, which results in moderate to severe bilateral movement impairments and spinal cord injury-related neuropathic pain, with in vivo electrophysiological measures of neural transmission in networks of spinal neurons integral to the development and persistence of the neuropathic pain state. We find that when intraspinal microstimulation is delivered to the ventral horn with the intent of enhancing voluntary movement, transmission through nociceptive specific and wide dynamic range neurons is significantly depressed in response to pain-related sensory feedback. By comparison, spinal responsiveness to non-pain-related sensory feedback is largely preserved. These results suggest that spinal stimulation paradigms could be intentionally designed to afford multi-modal therapeutic benefits, directly addressing the diverse, intersectional rehabilitation goals of people living with spinal cord injury.

Emergent epileptiform activity in spinal sensory circuits drives ectopic bursting in afferent axons and sensory dysfunction after cord injury.

Spinal cord injury leads to hyperexcitability and dysfunction in spinal sensory processing. As hyperexcitable circuits can become epileptiform, we explored whether such activity emerges in a thoracic spinal cord injury (SCI) contusion model of neuropathic pain. Recordings from spinal sensory axons in multiple below-lesion segmental dorsal roots demonstrated that SCI facilitated the emergence of spontaneous ectopic burst spiking in afferent axons, which were correlated across multiple adjacent dorsal roots. Burst frequency correlated with behavioral mechanosensitivity. The same bursting events were recruited by afferent stimulation, and timing interactions with ongoing spontaneous bursts revealed that recruitment was limited by a prolonged post-burst refractory period. Ectopic bursting in afferent axons was driven by GABAA receptor activation, presumably by conversion of subthreshold GABAergic interneuronal presynaptic axoaxonic inhibitory actions to suprathreshold spiking. Collectively, the emergence of stereotyped bursting circuitry with hypersynchrony, sensory input activation, post-burst refractory period, and reorganization of connectivity represent defining features of an epileptiform network. Indeed, these same features were reproduced in naive animals with the convulsant 4-aminopyridine (fampridine). We conclude that spinal cord injury promotes the emergence of epileptiform activity in spinal sensory networks that promote profound corruption of sensory signaling. This includes hyperexcitability and bursting by ectopic spiking in afferent axons that propagate bidirectionally by reentrant central and peripheral projections as well as sensory circuit hypoexcitability during the burst refractory period. More broadly, the work links circuit hyperexcitability to epileptiform circuit emergence, further strengthening it as a conceptual basis to understand features of sensory dysfunction and neuropathic pain.

Impact of Frailty on Functional Improvement Following Traumatic Spinal Cord Injury: A Japanese Single-Center Experience.

Study Design: This is a retrospective case series study. Objective: The aim of this study was to investigate whether frailty contributes to functional recovery in individuals with spinal cord injury (SCI). Methods: A total of 121 patients with SCI (106 cervical SCI, 15 thoracic SCI) discharged from our center over the past three years were studied. Moreover, 11-factor modified frailty index (mFI) scores, the length of hospital stays, the rate of returning home, and improvement in Spinal Cord Independence Measure (SCIM) scores were assessed retrospectively. Results: The average age at the time of injury for all 121 cases was 59.6 years. Based on pre-injury assessments, 24 cases were categorized as the Frail group, and 97 cases were categorized as the Robust group. The Frail group had SCIM improvement rates of 16.7% and a home discharge rate of 45.8%. In contrast, the Robust group had SCIM improvement rates of 33.5% and a home discharge rate of 68.0%, with statistically significant differences between the two groups. A significant negative correlation was observed between mFI scores and SCIM improvement rates (R = -0.231, p = 0.014). Conclusions: This study suggests that individuals with pre-existing frailty before SCI experience poorer SCIM improvement rates and face challenges in returning home.

Effect of Detraining on Muscle Strength, Functional Capacity, Mental Health, and Body Composition in Individuals with Spinal Cord Injury.

Spinal cord injury (SCI) is a condition that significantly affects the quality of life (QoL) of individuals, causing motor, physiological, social, and psychological impairments. Physical exercise plays a crucial role in maintaining the health and functional capacity of these individuals, helping to minimize the negative impacts of SCI. The aim of this study was to evaluate the effect of detraining (DT) (reduction or cessation of physical exercise) during the pandemic on five individuals with thoracic SCI. We assessed muscle strength using strength tests, functional capacity using a functional agility test, mental health using anxiety and depression inventories, and body composition using dual-energy X-ray absorptiometry (DEXA). The results after 33 months of DT showed significant losses in functional agility and MS, as well as a worsening in symptoms of anxiety and depression. It was observed that total body mass and fat mass (FM) exhibited varied behaviors among the individuals. Similarly, the results for lean body mass were heterogeneous, with one participant showing significant deterioration. It is concluded that DT caused by the pandemic worsened the physical and mental condition of individuals with SCI, highlighting the importance of continuous exercise for this population and underscoring the need for individual assessments to fully understand the impacts of DT.

Spinal cord injury etiology, severity, and care in East Asia: a cross-sectional analysis of the International Spinal Cord Society Database Project.

Cross-sectional study. To evaluate etiologic factors associated with spinal cord injury (SCI) severity and to identify predictive factors of reduction in SCI severity in six countries. SCI centers in Bangladesh, India, Malaysia, Nepal, Sri Lanka, and Thailand. Data from centers collected between October 2015 and February 2021 were analyzed using descriptive statistics and logistic regression. Among 2634 individuals, the leading cause of SCIs was falls (n = 1410, 54%); most occurred from ≥1 meter (n = 1078). Most single-level neurological injuries occurred in the thoracic region (n = 977, 39%). Greater than half of SCIs (n = 1423, 54%) were graded American Spinal Injury Association Impairment Scale (AIS) A. Thoracic SCIs accounted for 53% (n = 757) of all one-level AIS A SCIs. The percentage of thoracic SCIs graded AIS A (78%) was significantly higher than high cervical (52%), low cervical (48%), lumbar (24%), and sacral (31%) SCIs (p < 0.001). Regression analyses isolated predictive factors both of SCI severity and inpatient improvement. Four factors predicted severity: age, neurological level, etiology, and country of residence. Four factors predicted improvement: age, neurological level, AIS grade on intake, and country of residence. Findings can be used by healthcare providers and public health agencies in these countries to inform the public of the risk of SCI due to falls. Future studies should examine the social and occupational milieux of falls. Country-to-country comparisons of prehospital and inpatient care are also justified. Fall prevention policies can encourage the use of safety equipment when performing tasks at heights ≥1 meter.

Passive activity enhances residual control ability in patients with complete spinal cord injury.

JOURNAL/nrgr/04.03/01300535-202508000-00024/figure1/v/2024-09-30T120553Z/r/image-tiff Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level. However, because of prolonged inactivity, initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway. A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation, as measured by surface electromyography. In this study, we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury. Eleven patients with chronic complete thoracic spinal cord injury were recruited. Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol. The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation. Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity, the difference was not statistically significant. These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

Comparisons of Evoked Skin Vasomotor and Sudomotor Responses to Single Pulse Median Nerve Stimulation

The sensorimotor dysfunction caused by cervical and thoracic spinal cord injury (SCI) is concomitant with sympathetic nervous system dysfunction, evidenced by the high prevalence of orthostatic hypotension and autonomic dysreflexia. Although the International Standards for Neurological Classification of SCI evaluate sensorimotor function both above and below the injury level, there are limited quantitative measures for gauging sympathetic outflow and the extent of dysautonomia resulting from neurological damage. Despite studies on the effects of SCI on electrodermal activity (EDA) and blood pressure (BP), there is a lack of detailed feature comparisons involving EDA, skin vasomotor activity, and BP. Therefore, we investigated the relationship between EDA, skin vasomotor, and BP responses to sympathetic activation via median nerve stimulation in persons with and without SCI. Adults with and without SCI (cohort demographics presented in poster) participated in this study. Lead II electrocardiogram (ECG), pneumogram (P), photoplethysmogram (PPG), and EDA were recorded from either the trunk (ECG, P) or both limbs (PPG, EDA). Beat-by-beat BP was recorded from the middle finger of the left hand (VitalStream, CareTaker Medical). Evoked responses in the above signals were measured surrounding a cathodal electrical pulse (30 mA, 200 μs) delivered to the distal right median nerve 1-2 cm proximal and medial to the radial styloid process either during systole or diastole of the cardiac cycle. There were notable differences between baseline signals before and after the experimental session, along with a consistent reduction of limb temperature (&gt; 2° Celsius). Increases in EDA (greater than two standard deviations from baseline) were found across non-SCI participants following stimulation both during systole and diastole, along with skin vasoconstriction following the onset of EDA modulation (&gt; 50% of trials). Individual differences were noted in evoked responses to stimulation at systole vs. diastole. Furthermore, attenuated responses were observed in individuals with SCI. Stimulation caused no evoked signal response habituation across trials within participants. Additionally, evoked BP changes were not consistent across all individuals with respect to stimulation. Our results show a fixed relationship between evoked skin vasomotor and sudomotor responses to single pulse stimuli across participants and had consistent waveform features. Potential individual effects of stimulation delivered at systole vs. diastole warrant an in-depth analysis of reflex gating of sudomotor and skin vasomotor responses. This would present insight into the population with SCI, where dysfunction could greatly exaggerate reflex gating. 1R01NS131493-01. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Passive heat therapy to improve cardiometabolic health in persons with a spinal cord injury — a pilot study

Objective: To test the effect of repeated heat therapy on markers of inflammation, glucose metabolism and vascular health in persons with a spinal cord injury (SCI). It was hypothesized that the heat therapy intervention would lead to a reduction in the fasting concentration of inflammatory markers as well as an improvement in glucose tolerance and microvascular function.Methods: Five adults with thoracic SCI ((1 female, age: 43 (27 – 60) yrs, BMI: 29 (23 to 30) kg/m2, years since injury: 7 (1 – 11) yrs)) enrolled in an 8-week passive heat therapy intervention consisting of 24 session during which the oral temperature was elevated by 1°C by means of a water-perfused suit and heating blankets. The number of completed sessions, time to reach the desired oral temperature and adverse events were reported. Thermoregulatory and perceptual responses to a single passive heat therapy session were assessed during the first session of the intervention. Fasting interleukin-6 (IL-6), C-reactive protein (CRP) and glucose concentration were measured in plasma before and after the chronic intervention. Additionally, thermal hyperemia in sensate (i.e., arm) and insensate (i.e., leg) skin through laser Doppler flowmetry were determined at 39°C and 45°C pre- and post-intervention. Descriptive data are expressed as median (range).Results: The median time to reach a 1°C increase in oral temperature during passive heating was 53 (49 – 75) min, which was accompanied by a final mean skin temperature of 38.6 (36.5 – 38.9)°C, a thermal comfort of 2 (0 – 4) on a 0 to 5 ratings scale and a basic affect of +3 (+1 - +4) on a -5 to +5 rating scale. Four out of the five participants completed all prescribed passive heating sessions. However, in two participants a number of sessions (N = 10 and 2 out of 24 sessions) were stopped at 0.8°C due to thermal discomfort. There were no skin burns or signs of autonomic dysreflexia. All participants remained hemodynamically stable throughout the sessions. Resting IL-6 and CRP changed from 3.2 (2.7 – 10.5) pg/ml to 8.1 (7.6 – 11.1) pg/ml and 0.40 (0.14 – 1.16) to 1.11 (0.51 – 1.26) pg/ml, respectively. Fasting glucose concentration changed from 90.0 (85.5 – 206.0) mg/dl to 94.5 (69 – 266) mg/dl. Cutaneous vascular conductance at 39°C as a percentage of maximal vasodilation at the arm and leg changed from 23.2 (11.2 – 36.0)% to 30.4 (13.8 – 46.1)% and 34.3 (30.4 – 49.4)% to 47.4 (6.7 – 52.8)%, respectively. Conclusion: These preliminary findings suggest that it is feasible, well-tolerated and safe for persons with SCI to engage in repeated heat therapy. A full data set of this ongoing study is needed to provide more conclusive insight into its effects on cardiometabolic health outcomes. VA Rehabilitation R&amp;D (I21RX003724-01A1). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Musculoskeletal morbidity in adults with spinal cord injuries: A nationwide cohort study.

An increase in the demand for quality of life following spinal cord injuries (SCIs) is associated with an increase in musculoskeletal (MSK) pain, highlighting the need for preventive measure research. This study aimed to evaluate the incidence and hazards of MSK morbidities among Korean adults with SCIs, as well as the influence of SCI location on MSK morbidities. Patient populations were selected from Korean National Health Insurance Service data (n = 276). The control group included individuals without SCIs (n = 10,000). We compared the incidences and determined the unadjusted and adjusted hazard ratios (HRs) of common MSK morbidities (osteoarthritis, connective tissue disorders, sarcopenia, myalgia, neuralgia, rheumatoid arthritis, myositis, and musculoskeletal infections) based on the location of injury (cervical, thoracic, or lumbar). Adults with SCIs had a higher incidence of MSK morbidity (48.45% vs. 36.6%) and a lower survival probability than those without SCIs. The incidence of MSK morbidity and survival probabilities were not significantly different for cervical cord injuries, whereas both measures were significantly different for thoracic and lumbar injuries. SCI increases the risk of MSK morbidity. Lumbar SCI is associated with a higher incidence and risk of MSK morbidity than are cervical or thoracic SCIs.

Participation and autonomy, independence in activities of daily living and upper extremity functioning in individuals with spinal cord injury

Improvements in care and rehabilitation have resulted in a higher proportion of people living with spinal cord injury (SCI), which calls for an increased focus on participation and autonomy. This observational cross-sectional study investigated the impact of SCI on autonomy and how it correlates to activity performance and upper extremity functioning. A total of 25 adults (mean age 58 years) with chronic cervical or thoracic SCI were included. Self-perceived autonomy was measured with Impact on Participation and Autonomy questionnaire, independence in activities of daily living (ADL) with Spinal Cord Independence Measure, upper extremity functioning with Action Research Arm Test (ARAT) and kinematic measures of the drinking task. The results showed that most participants perceived injury-related restrictions in outdoor autonomy (80%), family role (76%), and in indoor autonomy (72%). Independence in self-care (r = 0.72), mobility (r = 0.59) and upper extremity kinematics of movement time (r = 0.63) and smoothness (r = 0.49) were correlated to indoors autonomy. Social life autonomy was correlated to self-care (r = 0.50) and ARAT (r = 0.41). In conclusion, autonomy was perceived restricted after SCI in several major life areas and correlated with independence in ADL and upper extremity functioning. The aspects of autonomy should be considered more in goal setting and clinical decision-making.

Thoracic spinal cord injury after surgical removal of a ruptured cerebellar arteriovenous malformation in a patient in the Concorde position: illustrative case.

Thoracic spinal cord injury after posterior cranial fossa surgery in younger patients is a rare complication. There have been reports of this complication in tumor and spine fields but not in vascular surgery. A 22-year-old-man experienced cerebellar arteriovenous malformation rupture, and the malformation was surgically removed with the man in the Concorde position. After surgery, the man had severe paraplegia, and a thoracic spinal cord injury was diagnosed. In younger patients, cervical hyperflexion in the Concorde position can cause thoracic spinal cord injury even in surgery for cerebrovascular disease.