Motor Complete Spinal Cord Injury Research Articles

A comparison of one year outcomes between standardized locomotor training and usual care after motor incomplete spinal cord injury: Community participation, quality of life and re-hospitalization

Context/Objective Spinal cord injury (SCI) often results in a significant loss of mobility and independence coinciding with reports of decreased quality of life (QOL), community participation, and medical complications often requiring re-hospitalization. Locomotor training (LT), the repetition of stepping-like patterning has shown beneficial effects for improving walking ability after motor incomplete SCI, but the potential impact of LT on psychosocial outcomes has not been well-established. The purpose of this study was to evaluate one year QOL, community participation and re-hospitalization outcomes between individuals who participated in a standardized LT program and those who received usual care (UC). Design/Setting/Participants A retrospective (nested case/control) analysis was completed using SCI Model Systems (SCIMS) data comparing one year post-injury outcomes between individuals with traumatic motor incomplete SCI who participated in standardized LT to those who received UC. Outcome Measures Outcomes compared include the following: Satisfaction with Life Scale (SWLS™), Craig Handicap Assessment and Reporting Technique-Short Form (CHART-SF™), and whether or not an individual was re-hospitalized during the first year of injury. Results Statistically significant improvements for the LT group were found in the following outcomes: SWLS (P = 0.019); and CHART subscales [mobility (P = <0.001)]; occupation (P = 0.028); with small to medium effects sizes. Conclusion Individuals who completed a standardized LT intervention reported greater improvements in satisfaction with life, community participation, and fewer re-hospitalizations at one year post-injury in comparison to those who received UC. Future randomized controlled trials are needed to verify these findings.

Associations between upper extremity functioning and kinematics in people with spinal cord injury

IntroductionMore knowledge of the relationships between kinematic measures and clinical assessments is required to guide clinical decision making and future research.ObjectivesTo determine which kinematic variables obtained during a drinking task were associated with clinical assessments of upper extremity functioning in people with spinal cord injury (SCI).MethodsIn total, 25 individuals with chronic cervical (n = 17) or thoracic (n = 8) complete (n = 14) or motor incomplete (n = 11) SCI (mean age 58.4, SD 13.8) were included. Kinematic data, including movement time, smoothness and joint angles was captured with a 5-camera optoelectronic system during a unimanual drinking task. Action Research Arm Test (ARAT), Sollerman Hand Function Test (SHFT) and basic hand classification of the Upper Extremity Data Set (ISCI-Hand) were used as clinical assessments. Multiple regression analysis was used to identify kinematic variables associated with clinical assessments after controlling for potential confounding factors, such as, age, severity of SCI, sensory function, and hand surgery.ResultsMovement time, smoothness and movement pattern kinematics including trunk displacement, elbow and wrist joint angles were correlated (p < 0.05) with all three clinical scales while the velocity-related kinematics and inter-joint coordination showed low correlations. Multiple regression analysis revealed that wrist angle combined with movement time or smoothness explained 82% and 77% of the total variance in ARAT and SHFT, respectively. Wrist angle alone explained 59% of the variance in ISCI-Hand. The proprioception of the hand increased the explanatory power in the models of ARAT and SHFT. Associations between kinematics and clinical assessments in the subgroup with cervical SCI were equivalent to the whole group analyses. The number of participants in the subgroup with thoracic SCI was small and only allowed limited analysis.ConclusionsWrist angle, movement time, movement smoothness are the most important kinematic variables associated with upper extremity clinical assessments in people with SCI. The results are most valid for individuals with cervical SCI. All three assessments are appropriate for SCI. Further research with larger representative sample of thoracic SCI needed.

Distinct patterns of spasticity and corticospinal connectivity following complete spinal cord injury.

Damage to corticospinal axons has implications for the development of spasticity following spinal cord injury (SCI). Here, we examined to what extent residual corticospinal connections and spasticity are present in muscles below the injury (quadriceps femoris and soleus) in humans with motor complete thoracic SCI. We found three distinct subgroups of people: participants with spasticity and corticospinal responses in the quadriceps femoris and soleus; participants with spasticity and corticospinal responses in the quadriceps femoris only; and participants with no spasticity or corticospinalresponses in either muscle. Spasticity and corticospinal responses were present in the quadriceps but never only in the soleus muscle, suggesting a proximal to distal gradient of symptoms of hyperreflexia. These results suggest that concomitant patterns of residual corticospinal connectivity and spasticity exist in humans with motor complete SCI and that a clinical examination of spasticity might be a good predictor of residual descending motor pathways in people with severe paralysis. The loss of corticospinal axons has implications for the development of spasticity following spinal cord injury (SCI). However, the extent to which residual corticospinal connections and spasticity are present across muscles below the injury remains unknown. To address this question, we tested spasticity using the Modified Ashworth Scale and transmission in the corticospinal pathway by examining motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the leg motor cortex (cortical MEPs) and by direct activation of corticospinal axons by electrical stimulation over the thoracic spine (thoracic MEPs), in the quadriceps femoris and soleus muscles, in 30 individuals with motor complete thoracic SCI. Cortical MEPs were also conditioned by thoracic electrical stimulation at intervals allowing their summation or collision. We found three distinct subgroups of participants: 47% showed spasticity in the quadriceps femoris and soleus muscles; 30% showed spasticity in the quadriceps femoris muscle only; and 23% showed no spasticity in either muscle. Although cortical MEPs were present only in the quadriceps in participants with spasticity, thoracic MEPs were present in both muscles when spasticity was present. Thoracic electrical stimulation facilitated and suppressed cortical MEPs, showing that both forms of stimulation activated similar corticospinal axons. Cortical and thoracic MEPs correlated with the degree of spasticity in both muscles. These results provide the first evidence that related patterns of residual corticospinal connectivity and spasticity exist in muscles below the injury after motor complete thoracic SCI and highlight that a clinical examination of spasticity can predict residual corticospinal connectivity after severe paralysis.

Exercise Improves Cardiorespiratory Fitness, but Not Arterial Health, after Spinal Cord Injury: The CHOICES Trial.

Arterial stiffness, as measured by carotid-femoral pulse wave velocity (cfPWV), is elevated after spinal cord injury (SCI). In the uninjured population, exercise training has been shown to reduce arterial stiffness. In a randomized, multi-center clinical trial, we evaluated the impact of two exercise interventions on cardiovascular disease risk factors in persons with chronic SCI. A total of 46 adults with motor-complete SCI with neurological levels of injury between the fourth cervical and sixth thoracic spinal cord segments (C4-T6) were randomly assigned to either body-weight-supported treadmill training (BWSTT) or arm-cycle ergometer training (ACET). Participants trained 3 days per week for 24 weeks. Exercise session duration progressed gradually to reach 30 and 60 min for ACET and BWSTT, respectively. The primary outcome was arterial stiffness, assessed by cfPWV, and was measured at baseline, 12 weeks of training, and at 24 weeks. Secondary outcomes included cardiorespiratory fitness (CRF) and cardiometabolic health measures and were measured before and after completion of training. Fourteen participants per intervention arm completed the exercise intervention. Our results show no effect of either exercise intervention on arterial stiffness (p = 0.07) and cardiometabolic health measures (p > 0.36). However, peak oxygen uptake increased with ACET compared with BWSTT (p = 0.04). The findings of this trial demonstrate that although 24 weeks of upper-body exercise improved CRF in persons with motor-complete SCI ≥T6, neither intervention resulted in improvements in arterial stiffness or cardiometabolic health measures. ClinicalTrials.gov identifier: NCT01718977.

Internal consistency and convergent validity of the International Spinal Cord Injury Quality of Life Basic Data Set at discharge from first rehabilitation.

This study is a cross-sectional analysis using data from the Swiss Spinal Cord Injury Cohort Study. To examine internal consistency and convergent validity of the International Spinal Cord Injury Quality of Life Basic Data Set (QoL-BDS) at discharge from first inpatient rehabilitation. The study was performed at four rehabilitation centers in Switzerland. Participants were Swiss residents aged over 16 years newly diagnosed with traumatic or non-traumatic spinal cord injury (SCI). Measures included the QoL-BDS, World Health Organization Quality of Life (WHOQOL) items, Hospital Anxiety and Depression Scale (HADS), and Spinal Cord Independence Measure III (SCIM). A total of 495 participants were included. In all, 57% had a traumatic SCI, 71.1% a motor complete SCI, and 33.3% had tetraplegia. Mean age was 53 (SD = 16.4) years and 68% were male. No floor or ceiling effects were found. Inter-correlations were strong (0.73-0.80) and Cronbach's alpha was good (0.88). QoL-BDS mean scores were 6.4 (SD = 2.2) for life satisfaction, 5.8 (SD = 2.4) for physical health, 6.9 (SD = 2.4) for psychological health, and 6.4 (SD = 2.1) for total QoL. Correlations with reference measures were strongest for QoL-BDS total and WHOQOL general quality of life (r = 0.67), QoL-BDS physical health and WHOQOL health and daily activities (r = 0.64 and 0.53), and QoL-BDS psychological health and HADS depression and anxiety (r = -0.64 and -0.69). SCIM correlated weakly with all QoL-BDS items. The QoL-BDS revealed no floor or ceiling effects and demonstrated good internal consistency and convergent validity in individuals with SCI assessed at discharge from first rehabilitation. This study supports the clinical routine use of the QoL-BDS.

Peak Torque Prediction Using Handgrip and Strength Predictors in Men and Women With Motor Complete Spinal Cord Injury.

To establish predictive equations for peak torque of muscle groups with totally and partially preserved innervation in individuals with motor complete spinal cord injury (SCI), based on hand dynamometry and strength predictor variables. The cross-sectional study conducted at a rehabilitation hospital consecutively recruited 108 men and women with SCI. All participants performed maximum peak torque tests for shoulder abduction/adduction (isokinetic), trunk flexion/extension (isometric), and handgrip strength testing (hand dynamometer) to establish predictive peak torque equations. The primary outcomes were peak torque variables. Handgrip strength, age, injury level, time since injury, age at injury, body mass, height, body mass index, and physical activity level were the secondary outcomes used as strength predictor variables. Handgrip strength was a predictor variable for shoulder abduction/adduction peak torque. The best predictive models for shoulder abduction/adduction peak torque exhibited R 2 = 0.57 and R 2 = 0.60, respectively (p ≤ .05). Injury level showed the highest significant predictive capacity for trunk flexion/extension peak torque models (R 2 = 0.38 and R 2 = 0.29; p ≤ .05). Shoulder abduction/adduction peak torque predictive equations may be an alternative for use in an accessible strength tool (hand dynamometry) to evaluate training and rehabilitation programs. Trunk flexion/extension peak torque equations exhibited moderate correlations and high standard error of the estimates and should be used with caution.

Recruitment order of motor neurons promoted by epidural stimulation in individuals with spinal cord injury.

Spinal cord epidural stimulation (scES) combined with activity-based training can promote motor function recovery in individuals with motor complete spinal cord injury (SCI). The characteristics of motor neuron recruitment, which influence different aspects of motor control, are still unknown when motor function is promoted by scES. Here, we enrolled five individuals with chronic motor complete SCI implanted with an scES unit to study the recruitment order of motor neurons during standing enabled by scES. We recorded high-density electromyography (HD-EMG) signals on the vastus lateralis muscle and inferred the order of recruitment of motor neurons from the relation between amplitude and conduction velocity of the scES-evoked EMG responses along the muscle fibers. Conduction velocity of scES-evoked responses was modulated over time, whereas stimulation parameters and standing condition remained constant, with average values ranging between 3.0 ± 0.1 and 4.4 ± 0.3 m/s. We found that the human spinal circuitry receiving epidural stimulation can promote both orderly (according to motor neuron size) and inverse trends of motor neuron recruitment, and that the engagement of spinal networks promoting rhythmic activity may favor orderly recruitment trends. Conversely, the different recruitment trends did not appear to be related with time since injury or scES implant, nor to the ability to achieve independent knees extension, nor to the conduction velocity values. The proposed approach can be implemented to investigate the effects of stimulation parameters and training-induced neural plasticity on the characteristics of motor neuron recruitment order, contributing to improve mechanistic understanding and effectiveness of epidural stimulation-promoted motor recovery after SCI.NEW & NOTEWORTHY After motor complete spinal cord injury, the human spinal cord receiving epidural stimulation can promote both orderly and inverse trends of motor neuron recruitment. The engagement of spinal networks involved in the generation of rhythmic activity seems to favor orderly recruitment trends.

Lateral Corticospinal Tract and Dorsal Column Damage: Predictive Relationships With Motor and Sensory Scores at Discharge From Acute Rehabilitation After Spinal Cord Injury

ObjectiveTo determine if lateral corticospinal tract (LCST) integrity demonstrates a significant predictive relationship with future ipsilateral lower extremity motor function (LEMS) and if dorsal column (DC) integrity demonstrates a significant predictive relationship with future light touch (LT) sensory function post spinal cord injury (SCI) at time of discharge from inpatient rehabilitation. DesignRetrospective analyses of imaging and clinical outcomes. SettingUniversity and academic hospital. ParticipantsA total of 151 participants (N=151) with SCI. InterventionsInpatient rehabilitation. Main Outcome MeasuresLEMS and LT scores at discharge from inpatient rehabilitation. ResultsIn 151 participants, right LCST spared tissue demonstrated a significant predictive relationship with right LEMS percentage recovered (β=0.56; 95% confidence interval [CI], 0.37-0.73; R=0.43; P<.001). Left LCST spared tissue demonstrated a significant predictive relationship with left LEMS percentage recovered (β=0.66; 95% CI, 0.50-0.82; R=0.51; P<.001). DC spared tissue demonstrated a significant predictive relationship with LT percentage recovered (β=0.69; 95% CI, 0.52-0.87; R=0.55; P<.001). When subgrouping the participants into motor complete vs incomplete SCI, motor relationships were no longer significant, but the sensory relationship remained significant. Those who had no voluntary motor function but recovered some also had significantly greater LCST spared tissue than those who did not recover motor function. ConclusionsLCST demonstrated significant moderate predictive relationships with lower extremity motor function at the time of discharge from inpatient rehabilitation, in an ipsilesional manner. DC integrity demonstrated a significant moderate predictive relationship with recovered function of LT. With further development, these neuroimaging methods might be used to predict potential deficits after SCI and to provide corresponding targeted interventions.

Evaluation of safety and performance of the self balancing walking system Atalante in patients with complete motor spinal cord injury.

Prospective, open label, observational. To present results of the first clinical study on a newly developed robotic exoskeleton (Atalante®, Wandercraft, Paris, France) that enables individuals with spinal cord injury (SCI) to perform ambulatory functions without technical aids. Two sites specialized in SCI rehabilitation, France. Inclusion criteria were presence of chronic complete SCI (AIS A) ranging from T5 to T12. The study protocol included 12 one-hour training sessions during 3 weeks. Patients walked on floor with robotic assistance and wore a harness connected to a mobile suspension system (without weight-bearing) to prevent from falling. Main outcome was the ability to walk 10 meters unassisted, secondary outcomes were assessment of other ambulatory functions, bladder and bowel functions, pain and spasticity. Twelve patients were enrolled, and 11 completed the protocol, mean age 33,9 years. Six patients had T6 levels of lesion or above. Seven patients passed the 10mWT at the 12th session unassisted (mean walking speed 0.13 m/s) while four required some human help. All patients succeeded at the other ambulatory tests (stand-up, sit-down, balance, turn). There were no significant change for bladder (Qualiveen) or bowel (NBD) functions, neuropathic pain (NPSI, NPRS), yet five patients reported a subjective improvement of their bowel function. Impact on spasticity was variable depending on the muscle examined (Ashworth). Ischial skin erosion was seen in one patient that needed local dressing. The Atalante system is safe and enables to perform ambulatory functions in patients with complete SCI.

Efficacy of Transcutaneous Spinal Stimulation versus Whole Body Vibration for Spasticity Reduction in Persons with Spinal Cord Injury.

Transcutaneous spinal stimulation (TSS) and whole-body vibration (WBV) each have a robust ability to activate spinal afferents. Both forms of stimulation have been shown to influence spasticity in persons with spinal cord injury (SCI), and may be viable non-pharmacological approaches to spasticity management. In thirty-two individuals with motor-incomplete SCI, we used a randomized crossover design to compare single-session effects of TSS versus WBV on quadriceps spasticity, as measured by the pendulum test. TSS (50 Hz, 400 μs, 15 min) was delivered in supine through a cathode placed over the thoracic spine (T11-T12) and an anode over the abdomen. WBV (50 Hz; eight 45-s bouts) was delivered with the participants standing on a vibration platform. Pendulum test first swing excursion (FSE) was measured at baseline, immediately post-intervention, and 15 and 45 min post-intervention. In the whole-group analysis, there were no between- or within-group differences of TSS and WBV in the change from baseline FSE to any post-intervention timepoints. Significant correlations between baseline FSE and change in FSE were associated with TSS at all timepoints. In the subgroup analysis, participants with more pronounced spasticity showed significant decreases in spasticity immediately post-TSS and 45 min post-TSS. TSS and WBV are feasible physical therapeutic interventions for the reduction of spasticity, with persistent effects.

Transspinal stimulation and step training alter function of spinal networks in complete spinal cord injury.

Pilot study (case series). The objective of this study was to establish spinal neurophysiological changes following high-frequency transspinal stimulation during robot-assisted step training in individuals with chronic motor complete spinal cord injury (SCI). University research laboratory (Klab4Recovery). Four individuals with motor complete SCI received an average of 18 sessions of transspinal stimulation over the thoracolumbar region with a pulse train at 333 Hz during robotic-assisted step training. Each session lasted ~1 h, with an average of 240 stimulations delivered during each training session. Before and after the combined intervention, we evaluated the amplitude modulation of the long-latency tibialis anterior (TA) flexion reflex and transspinal evoked potentials (TEP) recorded from flexors and extensors during assisted stepping, and the TEP recruitment curves at rest. The long-latency TA flexion reflex was depressed in all phases of the step cycle and the phase-dependent amplitude modulation of TEPs was altered during assisted stepping, while spinal motor output based on TEP recruitment curves was increased after the combined intervention. This is the first study documenting noninvasive transspinal stimulation coupled with locomotor training depresses flexion reflex excitability and concomitantly increases motoneuron output over multiple spinal segments for both flexors and extensors in people with motor complete SCI. While both transspinal stimulation and locomotor training may act via similar activity-dependent neuroplasticity mechanisms, combined interventions for rehabilitation of neurological disorders has not been systematically assessed. Our current findings support locomotor training induced neuroplasticity may be augmented with transspinal stimulation.

Neurophysiology of epidurally evoked spinal cord reflexes in clinically motor-complete posttraumatic spinal cord injury

Increased use of epidural Spinal Cord Stimulation (eSCS) for the rehabilitation of spinal cord injury (SCI) has highlighted the need for a greater understanding of the properties of reflex circuits in the isolated spinal cord, particularly in response to repetitive stimulation. Here, we investigate the frequency-dependence of modulation of short- and long-latency EMG responses of lower limb muscles in patients with SCI at rest. Single stimuli could evoke short-latency responses as well as long-latency (likely polysynaptic) responses. The short-latency component was enhanced at low frequencies and declined at higher rates. In all muscles, the effects of eSCS were more complex if polysynaptic activity was elicited, making the motor output become an active process expressed either as suppression, tonic or rhythmical activity. The polysynaptic activity threshold is not constant and might vary with different stimulation frequencies, which speaks for its temporal dependency. Polysynaptic components can be observed as direct responses, neuromodulation of monosynaptic responses or driving the muscle activity by themselves, depending on the frequency level. We suggest that the presence of polysynaptic activity could be a potential predictor for appropriate stimulation conditions. This work studies the complex behaviour of spinal circuits deprived of voluntary motor control from the brain and in the absence of any other inputs. This is done by describing the monosynaptic responses, polysynaptic activity, and its interaction through its input–output interaction with sustain stimulation that, unlike single stimuli used to study the reflex pathway, can strongly influence the interneuron circuitry and reveal a broader spectrum of connectivity.

How to Identify Responders and Nonresponders to Dorsal Root Ganglion-Stimulation Aimed at Eliciting Motor Responses in Chronic Spinal Cord Injury: Post Hoc Clinical and Neurophysiological Tests in a Case Series of Five Patients

ObjectiveWhile integrity of spinal pathways below injury is generally thought to be an important factor in the success‐rate of neuromodulation strategies for spinal cord injury (SCI), it is still unclear how the integrity of these pathways conveying the effects of stimulation should be assessed. In one of our institutional case series of five patients receiving dorsal root ganglion (DRG)‐stimulation for elicitation of immediate motor response in motor complete SCI, only two out of five patients presented as responders, showing immediate muscle activation upon DRG‐stimulation. The current study focuses on post hoc clinical‐neurophysiological tests performed within this patient series to illustrate their use for prediction of spinal pathway integrity, and presumably, responder‐status.Materials and MethodsIn a series of three nonresponders and two responders (all male, American Spinal Injury Association [ASIA] impairment scale [AIS] A/B), a test‐battery consisting of questionnaires, clinical measurements, as well as a series of neurophysiological measurements was performed less than eight months after participation in the initial study.ResultsNonresponders presented with a complete absence of spasticity and absence of leg reflexes. Additionally, nonresponders presented with close to no compound muscle action potentials (CMAPs) or Hofmann(H)‐reflexes. In contrast, both responders presented with clear spasticity, elicitable leg reflexes, CMAPs, H‐reflexes, and sensory nerve action potentials, although not always consistent for all tested muscles.ConclusionsPost hoc neurophysiological measurements were limited in clearly separating responders from nonresponders. Clinically, complete absence of spasticity‐related complaints in the nonresponders was a distinguishing factor between responders and nonresponders in this case series, which mimics prior reports of epidural electrical stimulation, potentially illustrating similarities in mechanisms of action between the two techniques. However, the problem remains that explicit use and report of preinclusion clinical‐neurophysiological measurements is missing in SCI literature. Identifying proper ways to assess these criteria might therefore be unnecessarily difficult, especially for nonestablished neuromodulation techniques.

Trajectories of Self-Efficacy, Depressed Mood, and Anxiety From Admission to Spinal Cord Injury Rehabilitation to 1 Year After Discharge

ObjectiveSelf-efficacy (SE) is an important determinant for the psychological adjustment of people with spinal cord injury (SCI). However, little is known about the course of SE during inpatient rehabilitation up to 1 year after discharge. The aim of this study was to determine latent trajectory classes of SE, depressive mood, and anxiety in people with SCI, as well as the interrelationships between these trajectories. DesignLongitudinal inception cohort study. SettingEight specialized SCI rehabilitation centers. ParticipantsThe participants (N=268) were mainly men 183 of 268 (68.3%) with a mean age of 55.6 years. Almost half had a traumatic SCI 135 of 268 (50.4%) and tetraplegia (53.7%), and the minority had a motor complete SCI (32.2%). InterventionsNot applicable. Main Outcome MeasuresSE was measured using the University of Washington Self-Efficacy Scale. In addition, the Hospital Anxiety and Depression Scale was used to asses distress and perform dual trajectory modeling analyses. ResultsThree trajectories of SE, indicating low, middle, and high SE, could be distinguished. Furthermore, a 2-class trajectory solution for depressive mood and a 4-class solution for anxiety were found to be most suitable. All trajectories were stable over time. Developmental connections between SE and depressive mood and between SE and anxiety were revealed. In particular, participants who adjusted well, reporting low scores on depressive mood and anxiety, could be identified by their high SE scores. However, the group of participants with high depressive mood scores and anxiety scores could not always be identified based on their SE trajectory. ConclusionsIn accordance with our hypotheses, distinct trajectories of SE, depressive mood, and anxiety were identified and high probabilities that SE trajectories were interrelated to the trajectories from depressive mood and anxiety were confirmed. Concurrent screening for SE and distress might best detect people at risk for adjustment problems.

Botulinum toxin type-A infiltration of the external anal sphincter to treat outlet constipation in motor incomplete spinal cord injury: pilot cohort study

Background Outlet constipation is a major problem in spinal cord injury (SCI) patients. We aimed to study the efficacy of external anal sphincter (EAS) infiltration with type-A botulinum toxin (BTX-A) in motor incomplete SCI patients with outlet constipation. Methods Double blind, randomized, placebo controlled, comparative study in 16 motor incomplete SCI subjects. Patients were randomly assigned toreceive100 UI of BTX-A (n = 9) or physiologic serum infiltration (n = 7) in the EAS under electromyographic guidance. Outcome measures included a questionnaire for clinical bowel function evaluation, colonic transit time and anorectal manometry. All assessments were done at baseline, 1 and 3 months after treatment. Results Fourteen patients completed the study. In the BTX-A group we observed an improvement of subjective perception of bowel function (p = 0.01), constipation (p = 0.02) and neurogenic bowel dysfunction score (p = 0.02). The anorectal manometry revealed are duction of EAS voluntary contraction pressure (p = 0.01). No changes were observed in the placebo group. No significant side effects were observed in none of the groups. Conclusion BTX-A infiltration of the EAS is a safe technique that in motor incomplete SCI, decreases the EAS contraction and the anal canal pressure during straining, and improves outlet constipation symptoms. Future studies in larger populations are needed.

Neurophysiological Changes After Paired Brain and Spinal Cord Stimulation Coupled With Locomotor Training in Human Spinal Cord Injury

Neurophysiological changes that involve activity-dependent neuroplasticity mechanisms via repeated stimulation and locomotor training are not commonly employed in research even though combination of interventions is a common clinical practice. In this randomized clinical trial, we established neurophysiological changes when transcranial magnetic stimulation (TMS) of the motor cortex was paired with transcutaneous thoracolumbar spinal (transspinal) stimulation in human spinal cord injury (SCI) delivered during locomotor training. We hypothesized that TMS delivered before transspinal (TMS-transspinal) stimulation promotes functional reorganization of spinal networks during stepping. In this protocol, TMS-induced corticospinal volleys arrive at the spinal cord at a sufficient time to interact with transspinal stimulation induced depolarization of alpha motoneurons over multiple spinal segments. We further hypothesized that TMS delivered after transspinal (transspinal-TMS) stimulation induces less pronounced effects. In this protocol, transspinal stimulation is delivered at time that allows transspinal stimulation induced action potentials to arrive at the motor cortex and affect descending motor volleys at the site of their origin. Fourteen individuals with motor incomplete and complete SCI participated in at least 25 sessions. Both stimulation protocols were delivered during the stance phase of the less impaired leg. Each training session consisted of 240 paired stimuli delivered over 10-min blocks. In transspinal-TMS, the left soleus H-reflex increased during the stance-phase and the right soleus H-reflex decreased at mid-swing. In TMS-transspinal no significant changes were found. When soleus H-reflexes were grouped based on the TMS-targeted limb, transspinal-TMS and locomotor training promoted H-reflex depression at swing phase, while TMS-transspinal and locomotor training resulted in facilitation of the soleus H-reflex at stance phase of the step cycle. Furthermore, both transspinal-TMS and TMS-transspinal paired-associative stimulation (PAS) and locomotor training promoted a more physiological modulation of motor activity and thus depolarization of motoneurons during assisted stepping. Our findings support that targeted non-invasive stimulation of corticospinal and spinal neuronal pathways coupled with locomotor training produce neurophysiological changes beneficial to stepping in humans with varying deficits of sensorimotor function after SCI.

Single-session effects of acute intermittent hypoxia on breathing function after human spinal cord injury

After spinal cord injury (SCI) respiratory complications are a leading cause of morbidity and mortality. Acute intermittent hypoxia (AIH) triggers spinal respiratory motor plasticity in rodent models, and repetitive AIH may have the potential to restore breathing capacity in those with SCI. As an initial approach to provide proof of principle for such effects, we tested single-session AIH effects on breathing function in adults with chronic SCI. 17 adults (13 males; 34.1 ± 14.5 years old; 13 motor complete SCI; >6 months post injury) completed two randomly ordered sessions, AIH versus sham. AIH consisted of 15, 1-min episodes (hypoxia: 10.3% O2; sham: 21% O2) interspersed with room air breathing (1.5 min, 21% oxygen); no attempt was made to regulate arterial CO2 levels. Blood oxygen saturation (SpO2), maximal inspiratory and expiratory pressures (MIP; MEP), forced vital capacity (FVC), and mouth occlusion pressure within 0.1 s (P0.1) were assessed. Outcomes were compared using nonparametric Wilcoxon's tests, or a 2 × 2 ANOVA. Baseline SpO2 was 97.2 ± 1.3% and was unchanged during sham experiments. During hypoxic episodes, SpO2 decreased to 84.7 ± 0.9%, and returned to baseline levels during normoxic intervals. Outcomes were unchanged from baseline post-sham. Greater increases in MIP were evident post AIH vs. sham (median values; +10.8 cmH2O vs. -2.6 cmH2O respectively, 95% confidence interval (−18.7) – (−4.3), p = .006) with a moderate Cohen's effect size (0.68). P0.1, MEP and FVC did not change post-AIH. A single AIH session increased maximal inspiratory pressure generation, but not other breathing functions in adults with SCI. Reasons may include greater spared innervation to inspiratory versus expiratory muscles or differences in the capacity for AIH-induced plasticity in inspiratory motor neuron pools. Based on our findings, the therapeutic potential of AIH on breathing capacity in people with SCI warrants further investigation.

Orthostatic hypotension is associated with impaired cardiac structure and function after spinal cord injury

Heart disease is a primary cause of death after spinal cord injury (SCI). A 20 mmHg or more reduction in systolic blood pressure (BP) when assuming the upright posture is termed orthostatic hypotension (OH). Epidemiological data in the general population established a causal relationship between OH and heart disease. Orthostatic hypotension and heart disease are widespread after SCI however, it is unknown if the severity of OH after SCI is associated with cardiac structure or function and markers of cardiac health. We aimed to understand this relationship combining an interventional rodent study and a cross-sectional clinical study, using gold standard invasive techniques and cardiac-optimized magnetic resonance imaging, respectively. We hypothesized that after SCI, OH severity would be associated with reduced cardiac structure and function as well as poorer markers of cardiac health. Twenty-one wistar rats underwent a complete transection at the T3 spinal segment. One week later, half of these animals were exposed to five one-minute intervals of simulated OH daily for eight weeks using a custom lower body negative pressure chamber (n=10; Fig. 1A). Nine weeks post-SCI, invasive pressure-volume catheterization and inferior vena cava occlusion were performed on both groups. Daily exposure to OH impaired left ventricle (LV) structure and function in rats with SCI as evidenced by reduced stroke volume (SV), cardiac output (Q), and end-systolic elastance (Ees), along with increased ventricular-vascular coupling (VVC) and arterial elastance (Ea; Fig. 1B). Guided by these interventional preclinical results, we next cross-sectionally tested this association in a group of eight individuals with motor-complete chronic SCI using 3-Tesla cardiac-optimized magnetic resonance imaging (Fig. 1C), 24-hour ambulatory blood pressure monitoring (Fig. 1D), and orthostatic tilt-table testing at 60 degrees following clinical guidelines (Fig. 1E). More severe OH was associated with impaired cardiac structure and poorer markers of cardiac health, indicated by increased LV mass, increased left atrial volume, and increased troponin T (Fig. 1F). Our translational research, using both interventional preclinical and cross-sectional clinical assessments, indicates that OH after SCI is associated with impaired cardiac structure and function as well as poorer markers of cardiac health. The next step is to test if mitigating OH after SCI prevents this decline.

Significance of the neurological level of injury as a prognostic predictor for motor complete cervical spinal cord injury patients

Objective: To investigate the usefulness of the combination of neurological findings and magnetic resonance imaging (MRI) as a prognostic predictor in patients with motor complete cervical spinal cord injury (CSCI) in the acute phase. Design: A cross-sectional analysis Setting: Department of Orthopaedic Surgery, Spinal Injuries Center Participants/Methods: Forty-two patients with an initial diagnosis of motor complete CSCI (AIS A, n = 29; AIS B, n = 13) within 72 h after injury were classified into the recovery group (Group R) and the non-recovery group (Group N), based on the presence or absence of motor recovery (conversion from AIS A/B to C/D) at three months after injury, respectively. The Neurological Level of Injury (NLI) at the initial diagnosis was investigated and the presumptive primary injured segment of the spinal cord was inferred from MRI performed at the initial diagnosis. We investigated whether or not the difference between the presumptive primary injured segment and the NLI exceeded one segment. The presence of a difference between the presumptive primary injured segment and the NLI was compared between Groups R and N. Results: The number of cases with the differences between the presumptive primary injured segment and the NLI was significantly higher in Group N than in Group R. Conclusion: The presence of differences between the presumptive primary injured segment and the NLI might be a poor improving prognostic predictor for motor complete CSCI. The NLI may be useful for predicting the recovery potential of patients with motor complete CSCI when combined with the MRI findings.

Toward Improving the Prediction of Functional Ambulation After Spinal Cord Injury Through the Inclusion of Limb Accelerations During Sleep and Personal Factors

ObjectiveTo determine if functional measures of ambulation can be accurately classified using clinical measures; demographics; personal, psychosocial, and environmental factors; and limb accelerations (LAs) obtained during sleep among individuals with chronic, motor incomplete spinal cord injury (SCI) in an effort to guide future, longitudinal predictions models. DesignCross-sectional, 1-5 days of data collection. SettingCommunity-based data collection. ParticipantsAdults with chronic (>1 year), motor incomplete SCI (N=27). InterventionsNot applicable. Main Outcome MeasuresAmbulatory ability based on the 10-m walk test (10MWT) or 6-minute walk test (6MWT) categorized as nonambulatory, household ambulator (0.01-0.44 m/s, 1-204 m), or community ambulator (>0.44 m/s, >204 m). A random forest model classified ambulatory ability using input features including clinical measures of strength, sensation, and spasticity; demographics; personal, psychosocial, and environmental factors including pain, environmental factors, health, social support, self-efficacy, resilience, and sleep quality; and LAs measured during sleep. Machine learning methods were used explicitly to avoid overfitting and minimize the possibility of biased results. ResultsThe combination of LA, clinical, and demographic features resulted in the highest classification accuracies for both functional ambulation outcomes (10MWT=70.4%, 6MWT=81.5%). Adding LAs, personal, psychosocial, and environmental factors, or both increased the accuracy of classification compared with the clinical/demographic features alone. Clinical measures of strength and sensation (especially knee flexion strength), LA measures of movement smoothness, and presence of pain and comorbidities were among the most important features selected for the models. ConclusionsThe addition of LA and personal, psychosocial, and environmental features increased functional ambulation classification accuracy in a population with incomplete SCI for whom improved prognosis for mobility outcomes is needed. These findings provide support for future longitudinal studies that use LA; personal, psychosocial, and environmental factors; and advanced analyses to improve clinical prediction rules for functional mobility outcomes.