Chronic Incomplete Spinal Cord Injury Research Articles

Variability of corticospinal and spinal reflex excitability for the ankle dorsiflexor tibialis anterior across repeated measurements in people with and without incomplete spinal cord injury

To adequately evaluate the corticospinal and spinal plasticity in health and disease, it is essential to understand whether and to what extent the corticospinal and spinal responses fluctuate systematically across multiple measurements. Thus, in this study, we examined the session-to-session variability of corticospinal excitability for the ankle dorsiflexor tibialis anterior (TA) in people with and without incomplete spinal cord injury (SCI). In neurologically normal participants, the following measures were obtained across 4 days at the same time of day (N = 13) or 4 sessions over a 12-h period (N = 9, at 8:00, 12:00, 16:00, and 20:00): maximum voluntary contraction (MVC), maximum M-wave and H-reflex (Mmax and Hmax), motor evoked potential (MEP) amplitude, and silent period (SP) after MEP. In participants with chronic incomplete SCI (N = 17), the same measures were obtained across 4 days. We found no clear diurnal variation in the spinal and corticospinal excitability of the TA in individuals with no known neurological conditions, and no systematic changes in any experimental measures of spinal and corticospinal excitability across four measurement days in individuals with or without SCI. Overall, mean deviations across four sessions remained in a range of 5–13% for all measures in participants with or without SCI. The study shows the limited extent of non-systematic session-to-session variability in the TA corticospinal excitability in individuals with and without chronic incomplete SCI, supporting the utility of corticospinal and spinal excitability measures in mechanistic investigation of neuromodulation interventions. The information provided through this study may serve as the reference in evaluating corticospinal plasticity across multiple experimental sessions.

The effect of high-frequency repetitive transcranial magnetic stimulation on motor recovery and gait parameters in chronic incomplete spinal cord injury: A randomized-controlled study.

This study aims to examine the effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) on gait parameters and lower extremity motor recovery in a more specific sample of individuals with chronic and traumatic incomplete spinal cord injury (iSCI). This double-blind, sham-controlled, randomized study included a total of 28 individuals (20 males, 8 females; mean age: 35.7±12.1 years; range, 18 to 45 years) with chronic (>1 year) traumatic iSCI. The participants were randomly allocated to either sham rTMS group (n=14) or real rTMS group (n=14). We compared the groups based on the lower extremity motor scores (LEMS), the temporal-spatial gait measurements using three-dimensional gait analysis, the Walking Index for SCI-II (WISCI-II), and 10-m walking test at baseline, three weeks (post-treatment) and five weeks (follow-up) after the treatment. The real rTMS group revealed a significant improvement in walking speed, LEMS score, and 10-m walking test after the treatment compared to baseline (p=0.001, p=0.002, and p=0.023, respectively). Changes in the LEMS score were significantly increased in the real rTMS group compared to the sham group at both three and five weeks (p=0.001 and p=0.001, respectively). No significant difference was observed in the other variables between the groups (p>0.05). Our study findings support the therapeutic effectiveness of rTMS on motor recovery in chronic iSCI. The rTMS can be used as an adjuvant therapy to conventional physiotherapy in the rehabilitation of patients with iSCI.

Acute intermittent hypoxia enhances strength, and modulates spatial distribution of muscle activation in persons with chronic incomplete spinal cord injury

Acute intermittent hypoxia (AIH) is an emerging technique for facilitating neural plasticity in individuals with chronic incomplete spinal cord injury (iSCI). A single sequence of AIH enhances hand grip strength and ankle plantarflexion torque, but underlying mechanisms are not yet clear. We sought to examine how AIH-induced changes in magnitude and spatial distribution of the electromyogram (EMG) of the biceps and triceps brachii contributes to improved strength. Seven individuals with iSCI visited the laboratory on two occasions, and received either AIH or Sham AIH intervention in a randomized order. AIH consisted of 15 brief (∼60s) periods of low oxygen (fraction of inspired O2 = 0.09) alternating with 60s of normoxia, whereas Sham AIH consisted of repeated exposures to normoxic air. High-density surface EMG of biceps and triceps brachii was recorded during maximal elbow flexion and extension. We then generated spatial maps which distinguished active muscle regions prior to and 60 min after AIH or Sham AIH. After an AIH sequence, elbow flexion and extension forces increased by 91.7 ± 88.4% and 51.7 ± 57.8% from baseline, respectively, whereas there was no difference after Sham AIH. Changes in strength were associated with an altered spatial distribution of EMG and increased root mean squared EMG amplitude in both biceps and triceps brachii muscles. These data suggest that altered motor unit activation profiles may underlie improved volitional strength after a single dose of AIH and warrant further investigation using single motor unit analysis techniques to further elucidate mechanisms of AIH-induced plasticity.

Spatial characteristics of reactive stepping among people living with chronic incomplete spinal cord injury

Objective: Compare the spatial characteristics of reactive stepping between individuals with chronic motor incomplete spinal cord injuries (iSCI) and able-bodied (AB) individuals. Design: Cross sectional. Setting: Lyndhurst Centre. Participants: Twelve individuals with iSCI (3 males, 53.6 ± 15.2 years old) and 11 age- and sex-matched AB individuals (3 males, 54.8 ± 14.0 years old). Interventions: The Lean-and-Release test was used to elicit reactive stepping. A horizontal cable, attached at waist height, was released when 8-12% body weight was supported in a forward lean position. Participants underwent up to 10 Lean-and-Release trials in a session. Kinematic and kinetic data were recorded. Outcome measures: The length, width and height of the first reactive step of each trial were calculated. Standard deviation between trials was calculated to represent the variability in step length, width and height within a participant. Among participants with iSCI, correlation coefficients were used to explore the relationship between step length and width variability and (1) Lean-and-Release test behavioral responses, (2) 3-month fall history, and (3) lower extremity strength. Results: Step length (P = 0.94), width (P = 0.52) and height (P = 0.97), normalized for participant height, did not differ between groups. Participants with iSCI showed greater variability in step length (P = 0.02) and width (P = 0.01), but not height (P = 0.32). No correlation was found between step length or width variability and behavioral responses, 3-month fall history, or lower extremity strength. Conclusions: Individuals with iSCI showed increased variability in length and width of reactive stepping compared to AB individuals, which may contribute to their impaired ability to execute single-step reactive responses. Trial registration: ClinicalTrials.gov identifier: NCT02960178.

Altered cutaneous reflexes to non-noxious stimuli in the triceps surae of people with chronic incomplete spinal cord injury.

Following spinal cord injury (SCI) task-dependent modulation of spinal reflexes are often impaired. To gain insight into the state of the spinal interneuronal pathways following injury, we studied the amplitude modulation of triceps surae cutaneous reflexes to non-noxious stimuli during standing and early-to-mid stance phase of walking in participants with and without chronic incomplete SCI. Reflex eliciting nerve stimulation was delivered to the superficial peroneal, sural, and distal tibial nerves about the ankle. Reflexes were analyzed in the short (SLR, 50-80 ms post stimulation onset) and the medium (MLR, 80-120 ms) latency response windows. Further, the relation between cutaneous and H-reflexes was also examined during standing. In participants without injuries the soleus SLR was modulated task-dependently with nerve specificity, and the soleus and medial gastrocnemius MLRs were modulated task-dependently. In contrast, participants with SCI, no task-dependent or nerve-specific modulation of triceps cutaneous reflexes was observed. The triceps surae cutaneous and H-reflexes were not correlated in either group (r = 0.01-0.37). The presence of cutaneous reflexes but the absence of significant amplitude modulation may suggest impaired function of spinal interneuronal pathways in this population. The lack of correlation between the cutaneous and H-reflexes may suggest that interneurons that are involved in H-reflex modulation and cutaneous reflex modulation do not receive common input, or the impact of the common input is outweighed by other input. Present findings highlight the importance of examining multiple spinal reflexes to better understanding spinal interneuronal pathways that affect motor control in people after SCI.

Acute Intermittent Hypoxia Increases Motor Unit Discharge Rates And Strength in Persons with SCI

<h3>Research Objectives</h3> To determine whether changes in motor unit discharge rates contribute to acute intermittent hypoxia (AIH)-induced improvements in volitional strength in persons with chronic incomplete spinal cord injury (iSCI) at the cervical level. <h3>Design</h3> Repeated-measures crossover study. <h3>Setting</h3> Rehabilitation hospital. <h3>Participants</h3> Seven individuals with iSCI completed two different sessions (AIH and SHAM) in a randomized order. <h3>Interventions</h3> AIH consisted of breathing 15 brief (∼60s) periods of low oxygen (9% O2) interspersed with 60s of normoxia (21% O2), whereas SHAM consisted of repeated exposures to normoxia. <h3>Main Outcome Measures</h3> We recorded high-density surface electromyograms from biceps and triceps brachii during maximal elbow flexion and extension torques, and decomposed these signals into individual motor unit spike trains before and 60 minutes after the interventions. <h3>Results</h3> After AIH, elbow flexion and extension torque increased by 54% (p = 0.0078; g = 0.58) and 59% (p = 0.04, g = 0.63) from baseline, respectively, whereas there was no change (i.e. < 10% change and p > 0.2 in both cases) after SHAM. Across muscles, motor unit discharge rates increased by 3.96 pulses per second (∼38%; p = 0.0015; G = 0.86) during maximal efforts, from pre to post AIH. Using generalized linear mixed models, we found that changes in motor unit discharge rates explained 54% (p = 0.0033) of the variance of changes in volitional torque. <h3>Conclusions</h3> These findings suggest that excitability and/or the activation of spinal motoneurons are augmented after AIH, providing a mechanism to explain AIH-induced increases in voluntary strength. Pending validation, AIH could potentially be used in conjunction with other therapies to enhance rehabilitation outcomes due to these enhancements in motor unit function and strength. <h3>Author(s) Disclosures</h3> The authors have nothing to disclose.

Effectiveness of robotic-assisted gait training on cardiopulmonary fitness and exercise capacity for incomplete spinal cord injury: A systematic review and meta-analysis of randomized controlled trials

Objective To determine the effects of robotic-assisted gait training on cardiopulmonary fitness and exercise capacity for people with incomplete spinal cord injury. Methods PubMed, Embase, Web of Science, PEDro, CENTRAL and CINAHL were searched from inception until September 4, 2022. Randomized controlled trials that evaluated the effects of robotic-assisted gait training on cardiopulmonary fitness and exercise capacity for individuals with incomplete spinal cord injury were selected. Mean differences (MD) with 95% confidence interval (CI) were calculated. The methodological quality was evaluated by the Cochrane Risk of Bias 2.0 tool. Subgroup analyses were conducted according to the time since injury. Results In total 19 studies involving 770 patients were eligible for analysis. Individuals with acute incomplete spinal cord injury in robotic-assisted gait training groups showed significantly greater improvements in 6-minute walking test (MD 53.32; 95% CI 33.49 to 73.15; P < 0.001), lower extremity motor scale (MD 5.22; 95% CI 3.63 to 6.80; P < 0.001) and walking index for spinal cord injury II (MD 3.18; 95% CI 1.34 to 5.02; P < 0.001). Robotic-assisted gait training improved peak oxygen consumption to a greater degree for chronic incomplete spinal cord injury patients (MD 4.90; 95% CI 0.96 to 8.84; P = 0.01). Conclusion Robot-assisted gait training may be a feasible and effective intervention in terms of cardiopulmonary fitness and exercise capacity for individuals with incomplete spinal cord injury.

Altered regulation of Ia afferent input during voluntary contraction in humans with spinal cord injury.

Sensory input converging on the spinal cord contributes to the control of movement. Although sensory pathways reorganize following spinal cord injury (SCI), the extent to which sensory input from Ia afferents is regulated during voluntary contraction after the injury remains largely unknown. To address this question, the soleus H-reflex and conditioning of the H-reflex by stimulating homonymous [depression of the soleus H-reflex evoked by common peroneal nerve (CPN) stimulation, D1 inhibition] and heteronymous (d), [monosynaptic Ia facilitation of the soleus H-reflex evoked by femoral nerve stimulation (FN facilitation)] nerves were tested at rest, and during tonic voluntary contraction in humans with and without chronic incomplete SCI. The soleus H-reflex size increased in both groups during voluntary contraction compared with rest, but to a lesser extent in SCI participants. Compared with rest, the D1 inhibition decreased during voluntary contraction in controls but it was still present in SCI participants. Further, the FN facilitation increased in controls but remained unchanged in SCI participants during voluntary contraction compared with rest. Changes in the D1 inhibition and FN facilitation were correlated with changes in the H-reflex during voluntary contraction, suggesting an association between outcomes. These findings provide the first demonstration that the regulation of Ia afferent input from homonymous and heteronymous nerves is altered during voluntary contraction in humans with SCI, resulting in lesser facilitatory effect on motor neurons.

Trans-Spinal Direct Current Stimulation in Spasticity: A Literature Mini-Review

Spasticity is common after a stroke and has a negative impact on functional and quality-of-life measures. There is an unmet medical need to provide safe and effective treatment using non-pharmacological approaches. Trans-spinal direct current stimulation (tsDCS) is an emerging modality for non-invasive neuromodulation that induces reduction of spinal excitability leading to a decrease in spasticity. We describe current treatment options for spasticity, including a literature review about the use of tsDCS in patients with spasticity. We found four clinical studies that used tsDCS to treat spasticity for different neurological conditions including hereditary spastic paraplegia, upper extremity spasticity following stroke, multiple sclerosis, and incomplete chronic spinal cord injury. Spasticity was the primary outcome in three of the studies and a secondary outcome in the final study. The three studies that addressed spasticity as the primary outcome found that active tsDCS decreased spasticity compared to sham. These studies suggest that tsDCS can modulate spinal motor and sensory spinal pathways through the use of specific electrode montages and stimulation parameters. This therapy can improve motor functions and may represent a viable treatment option for spasticity.

Stimulation of the cuneiform nucleus enables training and boosts recovery after spinal cord injury.

Severe spinal cord injuries result in permanent paraparesis in spite of the frequent sparing of small portions of white matter. Spared fibre tracts are often incapable of maintaining and modulating the activity of lower spinal motor centres. Effects of rehabilitative training thus remain limited.Here, we activated spared descending brainstem fibres by electrical deep brain stimulation of the cuneiform nucleus of the mesencephalic locomotor region, the main control centre for locomotion in the brainstem, in adult female Lewis rats.We show that deep brain stimulation of the cuneiform nucleus enhances the weak remaining motor drive in highly paraparetic rats with severe, incomplete spinal cord injuries and enables high-intensity locomotor training. Stimulation of the cuneiform nucleus during rehabilitative aquatraining after subchronic (n = 8 stimulated versus n = 7 unstimulated versus n = 7 untrained rats) and chronic (n = 14 stimulated versus n = 9 unstimulated versus n = 9 untrained rats) spinal cord injury re-established substantial locomotion and improved long-term recovery of motor function. We additionally identified a safety window of stimulation parameters ensuring context-specific locomotor control in intact rats (n = 18) and illustrate the importance of timing of treatment initiation after spinal cord injury (n = 14).This study highlights stimulation of the cuneiform nucleus as a highly promising therapeutic strategy to enhance motor recovery after subchronic and chronic incomplete spinal cord injury with direct clinical applicability.

Brain and spinal cord paired stimulation coupled with locomotor training affects polysynaptic flexion reflex circuits in human spinal cord injury.

Neurorecovery from locomotor training is well established in human spinal cord injury (SCI). However, neurorecovery resulting from combined interventions has not been widely studied. In this randomized clinical trial, we established the tibialis anterior (TA) flexion reflex modulation pattern when transcranial magnetic stimulation (TMS) of the primary motor cortex was paired with transcutaneous spinal cord (transspinal) stimulation over the thoracolumbar region during assisted step training. Single pulses of TMS were delivered either before (TMS-transspinal) or after (transspinal-TMS) transspinal stimulation during the stance phase of the less impaired leg. Eight individuals with chronic incomplete or complete SCI received at least 20 sessions of paired stimulation during assisted step training. Each session consisted of 240 paired stimuli delivered over 10-min blocks for 1h during robotic-assisted step training with the Lokomat6 Pro®. Body weight support, leg guidance force and treadmill speed were adjusted based on each participant's ability to step without knee buckling or toe dragging. Both the early and late TA flexion reflex remained unaltered after TMS-transspinal and locomotor training. In contrast, the early and late TA flexion reflexes were significantly depressed during stepping after transspinal-TMS and locomotor training. Reflex changes occurred at similar slopes and intercepts before and after training. Our findings support that targeted brain and spinal cord stimulation coupled with locomotor training reorganizes the function of flexion reflex pathways, which are a part of locomotor networks, in humans with varying levels of sensorimotor function after SCI.Trial registration number NCT04624607; Registered on November 12, 2020.

Feasibility of transcutaneous spinal direct current stimulation combined with locomotor training after spinal cord injury.

Feasibility study, consisting of random-order, cross-over study of a single intervention session, followed by a parallel-arm study of 16 sessions. To investigate the feasibility of a novel combinatorial approach with simultaneous delivery of transcutaneous spinal direct current stimulation (tsDCS) and locomotor training (tsDCS + LT) after spinal cord injury, compared to sham stimulation and locomotor training (sham + LT), and examine preliminary effects on walking function. Clinical research center in the southeastern United States. Eight individuals with chronic incomplete spinal cord injury (ISCI) completed the two-part protocol. Feasibility was assessed based on safety (adverse responses), tolerability (pain, spasticity, skin integrity), and protocol achievement (session duration, intensity). Walking function was assessed with the 10 m and 6 min walk tests. There were no major adverse responses. Minimal reports of skin irritation and musculoskeletal pain were consistent between groups. Average training peak heart rate as percent of maximum (mean(SD); tsDCS + LT: 66 (4)%, sham + LT: 69 (10)%) and Borg ratings of perceived exertion (tsDCS + LT: 17.5 (1.2), sham + LT: 14.4 (1.8)) indicate both groups trained at high intensities. Walking speed gains exceeded the minimal clinically important difference (MCID) in three of four who received tsDCS + LT (0.18 (0.29) m/s) and one of four in sham + LT (-0.05 (0.23) m/s). Gains in walking endurance exceeded the MCID in one of four in each group (tsDCS + LT: 36.4 (69.0) m, sham + LT: 4.9 (56.9) m). Combinatorial tsDCS and locomotor training is safe and feasible for individuals with chronic ISCI, even those with considerable walking impairment. Study outcomes support the need to investigate the efficacy of this approach.

Effect of long-term paired associative stimulation on the modulation of cortical sensorimotor oscillations after spinal cord injury

Study designA prospective interventional case series.ObjectivesTo explore changes in the modulation of cortical sensorimotor oscillations after long-term paired associative stimulation (PAS) in participants with spinal cord injury (SCI).SettingBioMag Laboratory, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.MethodsFive patients with chronic incomplete SCI received unilateral spinal PAS to upper limb for 16–22 days. Changes in the modulation of sensorimotor oscillations in response to tactile stimulus and active and imaginary hand movements were assessed with magnetoencephalography recorded before and after the intervention.ResultsPAS restored the modulation of sensorimotor oscillations in response to active hand movement in four patients, whereas the modulation following tactile stimulation remained unaltered. The observed change was larger in the hemisphere that received PAS and preceded the clinical effect of the intervention.ConclusionsLong-term spinal PAS treatment, which enhances the motor functions of SCI patients, also restores the modulation of cortical sensorimotor oscillations.

Assessment of mitochondrial respiratory capacity using minimally invasive and noninvasive techniques in persons with spinal cord injury.

Muscle biopsies are the gold standard to assess mitochondrial respiration; however, biopsies are not always a feasible approach in persons with spinal cord injury (SCI). Peripheral blood mononuclear cells (PBMCs) and near-infrared spectroscopy (NIRS) may alternatively be predictive of mitochondrial respiration. The purpose of the study was to evaluate whether mitochondrial respiration of PBMCs and NIRS are predictive of respiration of permeabilized muscle fibers after SCI. Twenty-two individuals with chronic complete and incomplete motor SCI between 18-65 years old were recruited to participate in the current trial. Using high-resolution respirometry, mitochondrial respiratory capacity was measured for PBMCs and muscle fibers of the vastus lateralis oxidizing complex I, II, and IV substrates. NIRS was used to assess mitochondrial capacity of the vastus lateralis with serial cuff occlusions and electrical stimulation. Positive relationships were observed between PBMC and permeabilized muscle fibers for mitochondrial complex IV (r = 0.86, P < 0.0001). Bland-Altman displayed agreement for complex IV (MD = 0.18, LOA = -0.86 to 1.21), between PBMCs and permeabilized muscles fibers. No significant relationships were observed between NIRS mitochondrial capacity and respiration in permeabilized muscle fibers. This is the first study to explore and support the agreement of less invasive clinical techniques for assessing mitochondrial respiratory capacity in individuals with SCI. The findings will assist in the application of PBMCs as a viable alternative for assessing mitochondrial health in persons with SCI in future clinical studies.

Combining Neuromodulation Strategies to Improve Locomotor Function in SCI: A Proof of Concept Case Study

<h3>Research Objectives</h3> Acute intermittent hypoxia (AIH) and transcutaneous spinal cord stimulation (tSCS) are two non-invasive neuromodulation treatments that have been shown to individually induce spinal plasticity in persons with chronic incomplete spinal cord injury (iSCI). However, these two interventions have never been tested in combination to see if their combined effect is greater than each intervention alone. This proof of concept case study investigated how AIH combined with tSCS during ambulation training may facilitate improvements in walking function in individuals with iSCI. <h3>Design</h3> Single-blind, randomized, crossover trial. <h3>Setting</h3> Outpatient, Rehabilitation Hospital. <h3>Participants</h3> 1 participant (male, 70 years) with chronic iSCI. <h3>Interventions</h3> The participant completed 3 arms, in random order: 1. AIH+tSCS 2. Sham-AIH+Sham-tSCS 3. Sham-AIH+tSCS Each arm consisted of 5 treatment sessions on consecutive days. <h3>Main Outcome Measures</h3> Assessments were performed at Baseline, Post-intervention (Post), and 1-week follow-up (1WFU), with a 4-week wash out between arms. Changes in gait performance were measured using the 10-meter walk test (10MWT) for fast and comfortable speeds, and the 6-minute walk test (6MWT). <h3>Results</h3> Overall, the participant showed potential improvements in his walking performance with AIH+tSCS at Post, relative to Baseline (10MWT-Fast: 5.6%; 10MWT-Comfortable: 7.0%; 6MWT: 15.6%), with further improvements at 1WFU (10MWT-Fast: 6.9%; 10MWT-Comfortable: 19.2%; 6MWT: 19.3%). The participant also showed potential improvements at Post, relative to Baseline with Sham-AIH+Sham-tSCS (10MWT-Fast: 12.2%; 10MWT-Comfortable: 6.6%; 6MWT: 15.1%) and with Sham-AIH+tSCS (10MWT-Fast: -2.5%; 10MWT-Comfortable: 15.3%; 6MWT: 6.0%). However, sustained improvements were not present at 1WFU with the Sham-AIH+Sham-tSCS (10MWT-Fast: 3.8%; 10MWT-Comfortable: -2.5%; 6MWT: 8.3%) or Sham-AIH+tSCS (10MWT-Fast: -3.9%; 10MWT-Comfortable: -5.5%; 6MWT: -2.1%), suggesting the combined intervention yielded retention effects. <h3>Conclusions</h3> AIH +tSCS with gait training may promote persistent improvements in walking function compared to tSCS with gait training or gait training alone in persons with iSCI. Further studies are warranted to investigate this novel, combinational neuromodulation strategy. <h3>Author(s) Disclosures</h3> The authors have no conflicts of interest to disclose.

Walking improvement in chronic incomplete spinal cord injury with exoskeleton robotic training (WISE): a randomized controlled trial

Study designClinical trial.ObjectiveTo demonstrate that a 12-week exoskeleton-based robotic gait training regimen can lead to a clinically meaningful improvement in independent gait speed, in community-dwelling participants with chronic incomplete spinal cord injury (iSCI).SettingOutpatient rehabilitation or research institute.MethodsMulti-site (United States), randomized, controlled trial, comparing exoskeleton gait training (12 weeks, 36 sessions) with standard gait training or no gait training (2:2:1 randomization) in chronic iSCI (>1 year post injury, AIS-C, and D), with residual stepping ability. The primary outcome measure was change in robot-independent gait speed (10-meter walk test, 10MWT) post 12-week intervention. Secondary outcomes included: Timed-Up-and-Go (TUG), 6-min walk test (6MWT), Walking Index for Spinal Cord Injury (WISCI-II) (assistance and devices), and treating therapist NASA-Task Load Index.ResultsTwenty-five participants completed the assessments and training as assigned (9 Ekso, 10 Active Control, 6 Passive Control). Mean change in gait speed at the primary endpoint was not statistically significant. The proportion of participants with improvement in clinical ambulation category from home to community speed post-intervention was greatest in the Ekso group (>1/2 Ekso, 1/3 Active Control, 0 Passive Control, p < 0.05). Improvements in secondary outcome measures were not significant.ConclusionsTwelve weeks of exoskeleton robotic training in chronic SCI participants with independent stepping ability at baseline can improve clinical ambulatory status. Improvements in raw gait speed were not statistically significant at the group level, which may guide future trials for participant inclusion criteria. While generally safe and tolerable, larger gains in ambulation might be associated with higher risk for non-serious adverse events.

The effects of virtual soccer game on balance, gait function, and kick speed in chronic incomplete spinal cord injury: a randomized controlled trial.

Participant-blinded comparative pre-post randomized controlled trial. To evaluate the effects of virtual soccer game on balance, gait function, and kick speed in individuals with spinal cord injuries. Forty participants with incomplete spinal cord injury (SCI) were included. The participants were randomized into either an experimental group (EG) or a control group for treatment 3 days/week over 4 weeks. The clinical outcomes included the results of the chair stand test (CST), timed up-and-go (TUG) test, and 10 m walking test (10MWT). The virtual reality (VR) content outcome measure was kick speed. The independent t-test results indicated that the participants in the EG exhibited superior performances in the CST, TUG test, 10MWT, and kick speed test (all P < 0.05). Our results provide novel, promising clinical evidence that VR rehabilitation improves both dynamic and static balance and reduces the risk of falls in patients with incomplete SCI of Asia impairment scale grades C-D.

Nerve root magnetic stimulation improves locomotor function following spinal cord injury with electrophysiological improvements and cortical synaptic reconstruction.

Following a spinal cord injury, there are usually a number of neural pathways that remain intact in the spinal cord. These residual nerve fibers are important, as they could be used to reconstruct the neural circuits that enable motor function. Our group previously designed a novel magnetic stimulation protocol, targeting the motor cortex and the spinal nerve roots, that led to significant improvements in locomotor function in patients with a chronic incomplete spinal cord injury. Here, we investigated how nerve root magnetic stimulation contributes to improved locomotor function using a rat model of spinal cord injury. Rats underwent surgery to clamp the spinal cord at T10; three days later, the rats were treated with repetitive magnetic stimulation (5 Hz, 25 pulses/train, 20 pulse trains) targeting the nerve roots at the L5-L6 vertebrae. The treatment was repeated five times a week over a period of three weeks. We found that the nerve root magnetic stimulation improved the locomotor function and enhanced nerve conduction in the injured spinal cord. In addition, the nerve root magnetic stimulation promoted the recovery of synaptic ultrastructure in the sensorimotor cortex. Overall, the results suggest that nerve root magnetic stimulation may be an effective, noninvasive method for mobilizing the residual spinal cord pathways to promote the recovery of locomotor function.

Walking with and without a robotic exoskeleton in people with incomplete spinal cord injury compared to a typical gait pattern.

Robotic exoskeleton (RE) enables individuals with lower extremity weakness or paralysis to stand and walk in a stereotypical pattern. Examine whether people with chronic incomplete spinal cord injury (SCI) demonstrate a more typical gait pattern when walking overground in a RE than when walking without. Motion analysis system synchronized with a surface electromyographic (EMG) was used to obtain temporospatial gait parameters, lower extremity kinematics, and muscle activity in ambulatory individuals with SCI and healthy adults. Temporospatial parameters and kinematics for participants with SCI (n = 12; age 41.4±12.5 years) with and without RE were significantly different than a typical gait (healthy adults: n = 15; age 26.2±8.3 years). EMG amplitudes during the stance phase of a typical gait were similar to those with SCI with and without RE, except the right rectus femoris (p = 0.005) and left gluteus medius (p = 0.014) when participants with SCI walked with RE. EMG amplitudes of participants with SCI during the swing phase were significantly greater compared to those of a typical gait, except for left medial hamstring with (p = 0.025) and without (p = 0.196) RE. First-time walking in a RE does not appear to produce a typical gait pattern in people with incomplete SCI.

The Rehabilitation Effects of Myoelectric Powered Wearable Orthotics on Improving Upper Extremity Function in Persons with SCI.

Upper extremity (UE) weakness and/or paralysis following spinal cord injury (SCI) can lead to a limited capacity to perform activities of daily living (ADL). Such disability significantly reduces an individual's level of independence. Further, restoration of UE motor function in people with SCI remains a high priority in rehabilitation and the field of assistive technology. The overall goal of this study was to evaluate the effects of a myoelectric-powered wearable orthosis (MPWO) manufactured by MyoMo, Inc. (Boston, MA) for UE movement assistance on ameliorating UE motor function in order to improve ADL and quality of life in people with SCI. Two male participants with chronic incomplete SCI (iSCI), a 75- and a 31-year-old with AIS D and B, respectively, underwent 18 sessions (over 6 weeks) of UE movement rehabilitation using the MPWO. Handgrip strength, active range of motion (AROM) of the hand, response time to initiate a movement, and muscles activations were examined before and after the rehabilitation training using the MPWO. The response time to initiate UE movements decreased, and handgrip strength and AROM improved after training with the MPWO. These preliminary data suggest that rehabilitation with the use of the UE-MPWO device could enhance the participants' UE activities that led to improved function.Clinical Relevance- These preliminary results from two individuals with iSCI suggest that training with UE-MPWO assistive devices may improve UE utilization during ADL for individuals with muscle weakness or paralysis but still possessing residual voluntary muscle activation capabilities.