Motor Complete Spinal Cord Injury Research Articles

A direct spinal cord-computer interface enables the control of the paralysed hand in spinal cord injury.

Paralysis of the muscles controlling the hand dramatically limits the quality of life for individuals living with spinal cord injury (SCI). Here, with a non-invasive neural interface, we demonstrate that eight motor complete SCI individuals (C5-C6) are still able to task-modulate in real-time the activity of populations of spinal motor neurons with residual neural pathways. In all SCI participants tested, we identified groups of motor units under voluntary control that encoded various hand movements. The motor unit discharges were mapped into more than 10 degrees of freedom, ranging from grasping to individual hand-digit flexion and extension. We then mapped the neural dynamics into a real-time controlled virtual hand. The SCI participants were able to match the cue hand posture by proportionally controlling four degrees of freedom (opening and closing the hand and index flexion/extension). These results demonstrate that wearable muscle sensors provide access to spared motor neurons that are fully under voluntary control in complete cervical SCI individuals. This non-invasive neural interface allows the investigation of motor neuron changes after the injury and has the potential to promote movement restoration when integrated with assistive devices.

Effects of releasing ankle joint during electrically evoked cycling in persons with motor complete spinal cord injury.

Literature has shown that simulated power production during conventional functional electrical stimulation (FES) cycling was improved by 14% by releasing the ankle joint from a fixed ankle setup and with the stimulation of the tibialis anterior and triceps surae. This study aims to investigate the effect of releasing the ankle joint on the pedal power production during FES cycling in persons with spinal cord injury (SCI). Seven persons with motor complete SCI participated in this study. All participants performed 1min of fixed-ankle and 1min of free-ankle FES cycling with two stimulation modes. In mode 1 participants performed FES-evoked cycling with the stimulation of quadriceps and hamstring muscles only (QH stimulation), while Mode 2 had stimulation of quadriceps, hamstring, tibialis anterior, and triceps surae muscles (QHT stimulation). The order of each trial was randomized in each participant. Free-ankle FES cycling offered greater ankle plantar- and dorsiflexion movement at specific slices of 20° crank angle intervals compared to fixed-ankle. There were significant differences in the mean and peak normalized pedal power outputs (POs) [F(1,500) = 14.03, p < 0.01 and F(1,500) = 7.111, p = 0.008, respectively] between fixed- and free-ankle QH stimulation, and fixed- and free-ankle QHT stimulation. Fixed-ankle QHT stimulation elevated the peak normalized pedal PO by 14.5% more than free-ankle QH stimulation. Releasing the ankle joint while providing no stimulation to the triceps surae and tibialis anterior reduces power output. The findings of this study suggest that QHT stimulation is necessary during free-ankle FES cycling to maintain power production as fixed-ankle.

Effectiveness and efficiency of telerehabilitation on functionality after spinal cord injury: A matched case-control study.

Telerehabilitation in spinal cord injury (teleSCI) is a growing field that can improve access to care and health outcomes in patients with spinal cord injury (SCI). The clinical effectiveness of teleSCI is not known. To compare independence in activities of daily living and mobility capacity in patients following teleSCI and matched controls undergoing traditional rehabilitation. Matched case-control study. TeleSCI occurring in home setting (cases) versus traditional rehabilitation on inpatient unit (controls). Forty-two consecutive patients with SCI followed with teleSCI were compared to 42 historical rehabilitation inpatients (controls) matched for age, time since injury to rehabilitation admission, level of injury (paraplegia/tetraplegia), complete or incomplete injury, and etiology (traumatic/nontraumatic). The teleSCI group (n = 42) was also compared to the complete cohort of historical controls (n = 613). The teleSCI group followed home-based telerehabilitation (3.5 h/day, 5 days/week, 67 days average duration) and historical controls followed in-person rehabilitation. The Functional Independence Measure (FIM), the Spinal Cord Independence Measure (SCIM) and the Walking Index for Spinal Cord Injury (WISCI). We formally compared gains, efficiency and effectiveness. International Standards for Neurological Classification of Spinal Cord Injury and the American Spinal Injury Association Impairment Scale (AIS) were used. The teleSCI group (57.1% nontraumatic, 71.4% paraplegia, 73.8% incomplete, 52.4% AIS grade D) showed no significant differences compared with historical controls in AIS grades, neurological levels, duration, gains, efficiency and effectiveness in FIM, SCIM, or WISCI, although the teleSCI cohort had significantly higher admission FIM scores compared with the complete cohort of historical controls. TeleSCI may provide similar improvements in mobility and functional outcomes as traditional rehabilitation in medically stable patients (predominantly with paraplegia and motor incomplete SCI) when provided with appropriate support and equipment.

Brief High-Velocity Motor Skill Training Increases Step Frequency and Improves Length/Frequency Coordination in Slow Walkers With Chronic Motor-Incomplete Spinal Cord Injury

ObjectiveTo quantify spatiotemporal coordination during overground walking among persons with motor-incomplete spinal cord injury (PwMISCI) by calculating the step length (SL)/step frequency (SF) ratio (ie, the Walk Ratio [WR]) and to examine the effects of motor skill training (MST) on the relationship between changes in these parameters and walking speed (WS). DesignBetween-day exploratory analysis. SettingResearch laboratory in a rehabilitation hospital ParticipantsPwMISCI (N=26). Interventions3-day high-velocity MST. Main Outcome MeasuresOverground WS, SL, SF, and WR measured during the 10-Meter Walk Test. ResultsAmong the full sample, MST was associated with increases in WS, SL, SF, and a decrease in the WR. Relative change in WS and SF was higher among slow (ΔWS=↑46%, ΔSF=↑28%) vs fast (ΔWS=↑16%, ΔSF=↑8%) walkers. Change in the WR differed between groups (slow: ΔWR=↓10%; fast: ΔWR=0%). Twenty-six percent of the variability observed in ΔWR among slow walkers could be explained by ΔSF, while ΔSL did not contribute to ΔWR. Among fast walkers, ΔSL accounted for more than twice the observed ΔWR (43%) compared to ΔSF (15%). ConclusionsOn the whole, WR values among PwMISCI are higher than previous reports in other neurologic populations; however, values among fast walkers were comparable to noninjured adults. Slow walkers demonstrated greater variability in the WR, with higher values associated with slower WS. Following MST, increases in WS coincided with a decrease in the WR among slow walkers, mediated primarily through an effect on SF. This finding may point to a specific mechanism by which MST facilitates improvements in WS among PwMISCI with greater mobility deficits.

Robotic Postural Training With Epidural Stimulation for the Recovery of Upright Postural Control in Individuals With Motor Complete Spinal Cord Injury: A Pilot Study.

Activity-based training and lumbosacral spinal cord epidural stimulation (scES) have the potential to restore standing and walking with self-balance assistance after motor complete spinal cord injury (SCI). However, improvements in upright postural control have not previously been addressed in this population. Here, we implemented a novel robotic postural training with scES, performed with free hands, to restore upright postural control in individuals with chronic, cervical (n = 5) or high-thoracic (n = 1) motor complete SCI, who had previously undergone stand training with scES using a walker or a standing frame for self-balance assistance. Robotic postural training re-enabled and/or largely improved the participants' ability to control steady standing, self-initiated trunk movements and upper limb reaching movements while standing with free hands, receiving only external assistance for pelvic control. These improvements were associated with neuromuscular activation pattern adaptations above and below the lesion. These findings suggest that the human spinal cord below the level of injury can generate meaningful postural responses when its excitability is modulated by scES, and can learn to improve these responses. Upright postural control improvements can enhance functional motor recovery promoted by scES after severe SCI.

Peak Slope Ratio of the Recruitment Curves Compared to Muscle Evoked Potentials to Optimize Standing Configurations with Percutaneous Epidural Stimulation after Spinal Cord Injury.

Background: Percutaneous spinal cord epidural stimulation (pSCES) has effectively restored varying levels of motor control in persons with motor complete spinal cord injury (SCI). Studying and standardizing the pSCES configurations may yield specific motor improvements. Previously, reliance on the amplitude of the SCES-evoked potentials (EPs) was used to determine the correct stimulation configurations. Methods: We, hereby, retrospectively examined the effects of wide and narrow-field configurations on establishing the motor recruitment curves of motor units of three different agonist-antagonist muscle groups. Magnetic resonance imaging was also used to individualize SCI participants (n = 4) according to their lesion characteristics. The slope of the recruitment curves using a six-degree polynomial function was calculated to derive the slope ratio for the agonist-antagonist muscle groups responsible for standing. Results: Axial damage ratios of the spinal cord ranged from 0.80 to 0.92, indicating at least some level of supraspinal connectivity for all participants. Despite the close range of these ratios, standing motor performance was enhanced using different stimulation configurations in the four persons with SCI. A slope ratio of ≥1 was considered for the recommended configurations necessary to achieve standing. The retrospectively identified configurations using the supine slope ratio of the recruitment curves of the motor units agreed with that visually inspected muscle EPs amplitude of the extensor relative to the flexor muscles in two of the four participants. Two participants managed to advance the selected configurations into independent standing performance after using tonic stimulation. The other two participants required different levels of assistance to attain standing performance. Conclusions: The findings suggest that the peak slope ratio of the muscle agonists-antagonists recruitment curves may potentially identify the pSCES configurations necessary to achieve standing in persons with SCI.

Effectiveness of Body Weight-Supported Gait Training on Gait and Balance for Motor-Incomplete Spinal Cord Injuries: A Systematic Review with Meta-Analysis.

This review aims to analyse the effectiveness of body weight-supported gait training for improving gait and balance in patients with motor-incomplete spinal cord injuries. Relevant articles were systematically searched in electronic databases to identify randomised controlled trials of body weight-supported gait training (either with methods of robotic, manual, and functional electrical stimulation assistance) versus conventional physical therapy or no intervention. Subjects were >16 years-old with motor-incomplete spinal cord injury (AIS C or D). Primary outcomes were gait-related parameters (functionality, endurance, and speed) and balance. Quality of life was included as a secondary outcome. Articles were selected up to 31 December 2023. Fifteen studies met the inclusion criteria (n = 673). Nine studies used robotic assistance, four trials performed manual assistance, one study functional electrical stimulation assistance, and one trial performed the intervention without guidance. Robot-assisted body weight-supported gait training improved walking functionality (SMD = 1.74, CI 95%: 1.09 to 2.39), walking endurance (MD = 26.59 m, CI 95% = 22.87 to 30.31), and balance (SMD = 0.63, CI 95% = 0.24 to 1.02). Body weight-supported gait training is not superior to conventional physiotherapy in gait and balance training in patients with motor-incomplete spinal cord injury. However, body weight-supported gait training with robotic assistance does improve walking functionality, walking endurance, and balance, but not walking speed.

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

To compare 1-year mobility outcomes of individuals with traumatic motor incomplete spinal cord injury (miSCI) who participated in standardized locomotor training (LT) within the first year of injury to those who did not. This retrospective case-control analysis conducted with six US rehabilitation hospitals used SCI Model Systems (SCIMS) data comparing 1-year postinjury outcomes between individuals with miSCI who participated in standardized LT to those who received usual care (UC). Participants were matched on age, gender, injury year, mode of mobility, and rehabilitation center. The primary outcome is the FIM Total Motor score. Other outcomes include the FIM Transfer Index, FIM Stairs, and self-reported independence with household mobility, community mobility, and stairs. LT participants reported significantly better FIM Total Motor (difference = 2.812, 95% confidence interval [CI] = 5.896, 17.282) and FIM Transfer Index scores (difference = 0.958, 95% CI = 0.993, 4.866). No significant between-group differences were found for FIM Stairs (difference = 0.713, 95% CI = -0.104, 1.530) or self-reported household mobility (odds ratio [OR] = 5.065, CI = 1.435, 17.884), community mobility (OR = 2.933, 95% CI = 0.868, 9.910), and stairs (OR = 5.817, 95% CI = 1.424, 23.756) after controlling for multiple comparisons. LT participants reported significantly greater improvements in primary and secondary measures of mobility and independence (FIM Total Motor score; FIM Transfer Index) compared to UC participants. Self-reported mobility outcomes were not significant between groups.

OVERGROUND ROBOTIC EXOSKELETON GAIT TRAINING INTENSITY IN PATIENTS WITH SCI

https://youtu.be/nreyPHEQASg BACKGROUND High-intensity gait training during inpatient rehabilitation (IPR) promotes functional recovery following spinal cord injury (SCI) and may be achieved with overground robotic exoskeleton gait training (OEGT). Due to neuromuscular and autonomic impairments associated with SCI, assessing intensity through heart rate response and perceived exertion during gait training may be inaccurate. Wearable metabolic systems (WMS) have been used to directly measure intensity using oxygen consumption (VO2) with SCI. However, the use of WMS to assess OEGT intensity during OEGT in IPR is unexplored. PURPOSE: To describe the use of WMS to measure physiological intensity of OEGT in patients with motor incomplete SCI during IPR. METHODS This observational study included adults aged 18 to 85 admitted to IPR with diagnosis of motor incomplete SCI who were eligible to initiate OEGT. OEGT intensity, duration, and step count were assessed during 1 OEGT session performed within 1 week of gait training initiation following IPR admission. Intensity was assessed by rate of perceived exertion (RPE) and VO2. VO2 was measured using a WMS worn during OEGT and expressed in metabolic equivalents (METs). Moderate and high intensity were defined as ≥ 3 and ≥ 6 METs, respectively, with 2.7 mL/min/kg of VO2 = 1 MET. RESULTS 4 participants [3 males; 1 non-Hispanic white, 2 Hispanic white, 1 Black] were aged 52±8.4 years with a body mass index of 28.4±3.2. Participants’ SCI characteristics were 3 diagnosed ASIA Impairment Scale (AIS) C, 1 AIS D; 2 tetraplegia and 2 paraplegia admitted within 30.5 [range=8-56] days after SCI. Duration of OEGT sessions (n=4) was 15:57 [range=10:23-19:43] minutes and participants completed 512 [287-761] steps. RPE was 4 [2-6], VO2 was 7.3 [3.05-15.6], and METs were 2.72 [1.1-5.8]. Three participants achieved ≥3 METs and ≥6 METs for 79-89.6% and 4.2-54.8% of the OEGT session, respectively. VO2 was highest in the AIS D participant. CONCLUSIONS WMS use was demonstrated to feasibly obtain intensity data of OEGT in adults with SCI during IPR. Future research should consider the utility of WMS to assess the capacity of OEGT to promote high-intensity gait training in this population during IPR.

Clinical Delivery of Overground Exoskeleton Gait Training in Persons With Spinal Cord Injury Across the Continuum of Care: A Retrospective Analysis.

After spinal cord injury (SCI), inpatient rehabilitation begins and continues through outpatient therapy. Overground exoskeleton gait training (OEGT) has been shown to be feasible in both settings, yet its use as an intervention across the continuum has not yet been reported. This study describes OEGT for patients with SCI across the continuum and its effects on clinical outcomes. Medical records of patients with SCI who completed at least one OEGT session during inpatient and outpatient rehabilitation from 2018 to 2021 were retrospectively reviewed. Demographic data, Walking Index for Spinal Cord Injury-II (WISCI-II) scores, and OEGT session details (frequency, "walk" time, "up" time, and step count) were extracted. Eighteen patients [male (83%), White (61%), aged 37.4 ± 15 years, with tetraplegia (50%), American Spinal Injury Association Impairment Scale A (28%), B (22%), C (39%), D (11%)] completed OEGT sessions (motor complete, 18.2 ± 10.3; motor incomplete, 16.7 ± 7.7) over approximately 18 weeks (motor complete, 15.1 ± 6.4; motor incomplete, 19.0 ± 8.2). Patients demonstrated improved OEGT session tolerance on device metrics including "walk" time (motor complete, 7:51 ± 4:42 to 24:50 ± 9:35 minutes; motor incomplete, 12:16 ± 6:01 to 20:01 ± 08:05 minutes), "up" time (motor complete, 16:03 ± 7:41 to 29:49 ± 12:44 minutes; motor incomplete, 16:38 ± 4:51 to 23:06 ± 08:50 minutes), and step count (motor complete, 340 ± 295.9 to 840.2 ± 379.4; motor incomplete, 372.3 ± 225.2 to 713.2 ± 272). Across therapy settings, patients with motor complete SCI experienced improvement in WISCI-II scores from 0 ± 0 at inpatient admission to 3 ± 4.6 by outpatient discharge, whereas the motor incomplete group demonstrated a change of 0.2 ± 0.4 to 9.0 ± 6.4. Patients completed OEGT across the therapy continuum. Patients with motor incomplete SCI experienced clinically meaningful improvements in walking function.

Recovery of Volitional Motor Control and Overground Walking in Participants With Chronic Clinically Motor Complete Spinal Cord Injury: Restoration of Rehabilitative Function With Epidural Spinal Stimulation (RESTORES) Trial-A Preliminary Study.

Spinal cord injury (SCI) is damage to any part of the spinal cord resulting in paralysis, bowel and/or bladder incontinence, and loss of sensation and other bodily functions. Current treatments for chronic SCI are focused on managing symptoms and preventing further damage to the spinal cord with limited neuro-restorative interventions. Recent research and independent clinical trials of spinal cord stimulation (SCS) or intensive neuro-rehabilitation including neuro-robotics in participants with SCI have suggested potential malleability of the neuronal networks for neurological recovery. We hypothesize that epidural electrical stimulation (EES) delivered via SCS in conjunction with mental imagery practice and robotic neuro-rehabilitation can synergistically improve volitional motor function below the level of injury in participants with chronic clinically motor-complete SCI. In our pilot clinical RESTORES trial (RESToration Of Rehabilitative function with Epidural spinal Stimulation), we investigate the feasibility of this combined multi-modal approach in restoring volitional motor control and achieving independent overground locomotion in participants with chronic motor complete thoracic SCI. Secondary aims are to assess the safety of this combination therapy including the off-label SCS usage as well as improving functional outcome measures. To our knowledge, this is the first clinical trial that investigates the combined impact of this multi-modal EES and rehabilitation strategy in participants with chronic motor complete SCI. Two participants with chronic motor-complete thoracic SCI were recruited for this pilot trial. Both participants have successfully regained volitional motor control below their level of SCI injury and achieved independent overground walking within a month of post-operative stimulation and rehabilitation. There were no adverse events noted in our trial and there was an improvement in post-operative truncal stability score. Results from this pilot study demonstrates the feasibility of combining EES, mental imagery practice and robotic rehabilitation in improving volitional motor control below level of SCI injury and restoring independent overground walking for participants with chronic motor-complete SCI. Our team believes that this provides very exciting promise in a field currently devoid of disease-modifying therapies.

Effects of a lower limb walking exoskeleton on quality of life and activities of daily living in patients with complete spinal cord injury: A randomized controlled trial.

In recent years, lower limb walking exoskeletons have been widely used in the study of spinal cord injury (SCI). To explore the effect of a lower limb walking exoskeleton on quality of life and functional independence in patients with motor complete SCI. This was a multi-center, single blind, randomized controlled trial. A total of 16 SCI patients were randomly assigned to either the exoskeleton-assisted walking (EAW) group (n= 8) or the conventional group (n= 8). Both groups received conventional rehabilitation training, including aerobic exercise and strength training. The EAW group additionally conducted the exoskeleton-assisted walking training using an AIDER powered robotic exoskeleton for 40-50 minutes, 5 times/week for 8weeks. World Health Organization quality of life-BREF (WHOQOL-BREF) and the Spinal Cord Independence Measure III (SCIM-III) were used for assessment before and after training. There was an increasing tendency of scores in the psychological health, physical health, and social relationships domain of WHOQOL-BREF in the EAW group after the intervention compared with the pre-intervention period, but there was no significant difference (P> 0.05). SCIM-III scores increased in both groups compared to pre-training, with only the conventional group showing a significant difference after 8weeks of training (P< 0.05). A lower limb walking exoskeleton may have potential benefits for quality of life and activities of daily living in patients with motor complete SCI.

Identification of Spared and Proportionally Controllable Hand Motor Dimensions in Motor Complete Spinal Cord Injuries Using Latent Manifold Analysis.

The loss of bilateral hand function is a debilitating challenge for millions of individuals that suffered a motor-complete spinal cord injury (SCI). We have recently demonstrated in eight tetraplegic individuals the presence of highly functional spared spinal motor neurons in the extrinsic muscles of the hand that are still capable of generating proportional flexion and extension signals. In this work, we hypothesized that an artificial intelligence (AI) system could automatically learn the spared electromyographic (EMG) patterns that encode the attempted movements of the paralyzed digits. We constrained the AI to continuously output the attempted movements in the form of a digital hand so that this signal could be used to control any assistive system (e.g. exoskeletons, electrical stimulation). We trained a convolutional neural network using data from 13 uninjured (control) participants and 8 tetraplegic participants (7 motor-complete, 1 incomplete) to study the latent space learned by the AI. Our model can automatically differentiate between eight different hand movements, including individual finger flexions, grasps, and pinches, achieving a mean accuracy of 98.3% within the SCI group. Analysis of the latent space of the model revealed that proportionally controllable movements exhibited an elliptical path, while movements lacking proportional control followed a chaotic trajectory. We found that proportional control of a movement can only be correctly estimated if the latent space embedding of the movement follows an elliptical path (correlation =0.73; p <0.001). These findings emphasize the reliability of the proposed system for closed-loop applications that require an accurate estimate of spinal cord motor output.

Consecutive Transcutaneous and Epidural Spinal Cord Neuromodulation to Modify Clinical Complete Paralysis—the Proof of Concept

ObjectiveTo evaluate the effect of transcutaneous (tSCS) and epidural electrical spinal cord stimulation (EES) in facilitating volitional movements, balance, and nonmotor functions, in this observational study, tSCS and EES were consecutively tested in 2 participants with motor complete spinal cord injury (SCI). Participants and MethodsTwo participants (a 48-year-old woman and a 28-year-old man), both classified as motor complete spinal injury, were enrolled in the study. Both participants went through a unified protocol, such as an initial electrophysiological assessment of neural connectivity, consecutive tSCS and EES combined with 8 wks of motor training with electromyography (EMG) and kinematic evaluation. The study was conducted from May 1, 2019, to December 31, 2021. ResultsIn both participants, tSCS reported a minimal improvement in voluntary movements still essential to start tSCS-enabled rehabilitation. Compared with tSCS, following EES showed immediate improvement in voluntary movements, whereas tSCS was more effective in improving balance and posture. Continuous improvement in nonmotor functions was found during tSCS-enabled and then during EES-enabled motor training. ConclusionResults report a significant difference in the effect of tSCS and EES on the recovery of neurologic functions and support consecutive tSCS and EES applications as a potential therapy for SCI. The proposed approach may help in selecting patients with SCI responsive to neuromodulation. It would also help initiate neuromodulation and rehabilitation therapy early, particularly for motor complete SCI with minimal effect from conventional rehabilitation.

Development of a Hypercoagulable-Hypofibrinolytic State Early After Spinal Cord Injury

ObjectivesTo determine whether spinal cord injury (SCI) is associated with adverse changes in coagulation and fibrinolytic factors that underlie thrombogenesis and contribute to atherothrombotic events such as myocardial infarctions (MIs) and strokes. DesignCross-sectional study. SettingNeurorehabilitation hospital and general community. ParticipantsThirty young and middle-aged (20-58 years) adults (N=30) were studied: 14 non-injured community dwelling adults. (11M/4F) and 16 with subacute tetraplegic motor complete SCI during initial inpatient rehabilitation (13M/3F; time since injury: 11.8±5.3 wk). InterventionsNot applicable. Main Outcome MeasuresCirculating markers of coagulation [von Willebrand factor (vWf) and factors VII, VIII, and X], the fibrinolytic system [tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) antigen and activity], and fibrin formation (D-dimer) were determined by enzyme immunoassay. ResultsThirty young and middle-aged (20-58 years) adults were studied: 14 non-injured (11M/4F) and 16 with subacute tetraplegic motor complete SCI (13M/3F; time since injury: range 4-25 wk). Circulating levels of coagulation factors VII, VIII, and X were significantly higher (∼20%-45%; P<.05) in the adults with SCI than non-injured adults, whereas vWf was similar between groups. Fibrinolytic markers were adversely disrupted with SCI with t-PA antigen, PAI-1 antigen and PAI-1 activity were markedly higher (∼50%-800%; P<.05) in adults with SCI compared with non-injured adults. The molar concentration ratio of active t-PA to PAI-1 was significantly higher (∼350%) in adults with SCI. Concordant with coagulation cascade activation and fibrinolytic system inhibition, D-dimer concentrations were markedly ∼70% higher (P<.05) in adults with SCI compared with non-injured adults. ConclusionsSubacute tetraplegic motor complete SCI is associated with a prothrombotic hemostatic profile. Adverse changes in the coagulation cascade and fibrinolytic system appear to occur early after injury and may contribute to the increased atherothrombotic risk in adults living with SCI.

Spasticity Predicts Motor Recovery for Patients with Subacute Motor Complete Spinal Cord Injury.

A motor complete spinal cord injury (SCI) results in the loss of voluntary motor control below the point of injury. Some of these patients can regain partial motor function through inpatient rehabilitation; however, there is currently no biomarker to easily identify which patients have this potential. Evidence indicates that spasticity could be that marker. Patients with motor complete SCI who exhibit spasticity show preservation of descending motor pathways, the pathways necessary for motor signals to be carried from the brain to the target muscle. We hypothesized that the presence of spasticity predicts motor recovery after subacute motor complete SCI. Spasticity (Modified Ashworth Scale and pendulum test) and descending connectivity (motor evoked potentials) were tested in the rectus femoris muscle in patients with subacute motor complete (n = 36) and motor incomplete (n = 30) SCI. Motor recovery was assessed by using the International Standards for Neurological Classification of Spinal Cord Injury and the American Spinal Injury Association Impairment Scale (AIS). All measurements were taken at admission and discharge from inpatient rehabilitation. We found that motor complete SCI patients with spasticity improved in motor scores and showed AIS conversion to either motor or sensory incomplete. Conversely, patients without spasticity showed no changes in motor scores and AIS conversion. In incomplete SCI patients, motor scores improved and AIS conversion occurred regardless of spasticity. These findings suggest that spasticity represents an easy-to-use clinical outcome that might help to predict motor recovery after severe SCI. This knowledge can improve inpatient rehabilitation effectiveness for motor complete SCI patients. ANN NEUROL 2023.

Characteristics Associated with Bone Loss after Spinal Cord Injury: Implications for Hip Region Vulnerability.

In individuals with spinal cord injury (SCI), bone loss progresses rapidly to the area below the level of injury, leading to an increased risk of fracture. However, there are limited data regarding SCI-relevant characteristics for bone loss and the degree of bone loss in individuals with SCI compared with that in non-SCI community-dwelling adults. Data from men with SCI who underwent dual-energy X-ray absorptiometry at the National Rehabilitation Center (2008 to 2020) between 12 and 36 months after injury were collected and analyzed. Community-dwelling men were matched 1:1 for age, height, and weight as the control group, using data from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008 to 2011). A comparison of the SCI and the matched control group revealed significantly lower hip region T-scores in the SCI group, whereas the lumbar spine T-score did not differ between groups. Among the 113 men with SCI, the paraplegia group exhibited significantly higher Z-scores of the hip region than the tetraplegia group. Participants with motor-incomplete SCI showed relatively preserved Z-scores of the hip region compared to those of the lumbar region. Moreover, in participants with SCI, the percentage of skeletal muscle displayed a moderate positive correlation with femoral neck Z-scores. Men with SCI exhibited significantly lower bone mineral density of the hip region than community-dwelling men. Paraplegia rather than tetraplegia, and motor incompleteness rather than motor completeness were protective factors in the hip region. Caution for loss of skeletal muscle mass or increased adiposity is also required.

Stabilizing leaning postures with feedback controlled functional neuromuscular stimulation after trunk paralysis.

Spinal cord injury (SCI) can cause paralysis of trunk and hip musculature that negatively impacts seated balance and ability to lean away from an upright posture and interact fully with the environment. Constant levels of electrical stimulation of peripheral nerves can activate typically paralyzed muscles and aid in maintaining a single upright seated posture. However, in the absence of a feedback controller, such seated postures and leaning motions are inherently unstable and unable to respond to perturbations. Three individuals with motor complete SCI who had previously received a neuroprosthesis capable of activating the hip and trunk musculature volunteered for this study. Subject-specific muscle synergies were identified through system identification of the lumbar moments produced via neural stimulation. Synergy-based calculations determined the real-time stimulation parameters required to assume leaning postures. When combined with a proportional, integral, derivative (PID) feedback controller and an accelerometer to infer trunk orientation, all individuals were able to assume non-erect postures of 30-40° flexion and 15° lateral bending. Leaning postures increased forward reaching capabilities by 10.2, 46.7, and 16 cm respectively for each subject when compared with no stimulation. Additionally, the leaning controllers were able to resist perturbations of up to 90 N, and all subjects perceived the leaning postures as moderately to very stable. Implementation of leaning controllers for neuroprostheses have the potential of expanding workspaces, increasing independence, and facilitating activities of daily living for individuals with paralysis.

Lack of improvement in anorectal manometry parameters after implementation of a pelvic floor/anal sphincter biofeedback in persons with motor-incomplete spinal cord injury.

Effect of biofeedback on improving anorectal manometric parameters in incomplete spinal cord injury is unknown. A short-term biofeedback program investigated any effect on anorectal manometric parameters without correlation to bowel symptoms. This prospective uncontrolled interventional study comprised three study subject groups, Group 1: sensory/motor-complete American Spinal Injury Association Impairment Scale (AIS) A SCI (n = 13); Group 2 (biofeedback group): sensory incomplete AIS B SCI (n = 17) (n = 3), and motor-incomplete AIS C SCI (n = 8), and AIS D SCI (n = 6); and Group 3: able-bodied (AB) controls (n = 12). High-resolution anorectal manometry (HR-ARM) was applied to establish baseline characteristics in all subjects for anorectal pressure, volume, length of pressure zones, and duration of sphincter squeeze pressure. SCI participants with motor-incomplete SCI were enrolled in pelvic floor/anal sphincter bowel biofeedback training (2 × 6-week training periods comprised of two training sessions per week for 30-45 min per session). HR-ARM was also performed after each of the 6-week periods of biofeedback training. Compared to motor-complete or motor-incomplete SCI participants, AB subjects had higher mean intra-rectal pressure, maximal sphincteric pressure, residual anal pressure, recto-anal pressure gradient, and duration of squeeze (p < 0.05 for each of the endpoints). No significant difference was evident at baseline between the motor-complete and motor-incomplete SCI groups. In motor-incomplete SCI subjects, the pelvic floor/anal sphincter biofeedback protocol failed to improve HR-ARM parameters. Biofeedback training program did not improve anal manometric parameters in subjects with motor-incomplete or sensory-incomplete SCI. Biofeedback did not change physiology, and its effects on symptoms are unknown. Utility of biofeedback is limited in patients with incomplete spinal cord injury in terms of improving HR-ARM parameters.

Student Competition (Knowledge Generation) ID 1985170

Background/Objectives Functional electrical stimulation (FES)-assisted arm and leg (A&amp;L) cycling is an effective rehabilitative intervention for improving walking following an incomplete spinal cord injury (SCI). The goal of this study was to assess the potential benefits of combining transcutaneous spinal cord stimulation (tSCS) with A&amp;L cycling to potentially improve functional mobility and activities of daily living for persons living with motor complete SCI. Methods This is a case study of a participant with AIS B SCI. The participant has been undergoing FES-assisted A&amp;L cycling training combined with cervical and lumbar tSCS (1 hr/day, 5 days/week) for 37 weeks. Assessments were performed pre-training and every 6 weeks thereafter and include the International Standards for Neurological Classification of SCI (ISNCSCI), time able to stand while assisted, and training load of each exercise session. Results Although there were no changes in the ISNCSCI scores, the duration of assisted standing increased from 10s per-training to 33.5s at 36 weeks post-training. Interestingly, the addition of tSCS enhanced standing duration to 38.5s. Moreover, the total power output exerted by the participant consistently increased over time. Conclusion This study provides, for the first time, evidence that FES-assisted A&amp;L cycling paired with non-invasive tSCS can be safely completed after severe SCI and leads to improvements in training load and assisted standing. Additional assessments will be incorporated to further identify improvements in function and quality of life. Future work will assess the benefits of using epidural spinal cord stimulation combined with A&amp;L cycling after motor complete SCI.