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

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

Non-invasive spinal cord electrical stimulation for arm and hand function in chronic tetraplegia: a safety and efficacy trial.

Cervical spinal cord injury (SCI) leads to permanent impairment of arm and hand functions. Here we conducted a prospective, single-arm, multicenter, open-label, non-significant risk trial that evaluated the safety and efficacy of ARCEX Therapy to improve arm and hand functions in people with chronic SCI. ARCEX Therapy involves the delivery of externally applied electrical stimulation over the cervical spinal cord during structured rehabilitation. The primary endpoints were safety and efficacy as measured by whether the majority of participants exhibited significant improvement in both strength and functional performance in response to ARCEX Therapy compared to the end of an equivalent period of rehabilitation alone. Sixty participants completed the protocol. No serious adverse events related to ARCEX Therapy were reported, and the primary effectiveness endpoint was met. Seventy-two percent of participants demonstrated improvements greater than the minimally important difference criteria for both strength and functional domains. Secondary endpoint analysis revealed significant improvements in fingertip pinch force, hand prehension and strength, upper extremity motor and sensory abilities and self-reported increases in quality of life. These results demonstrate the safety and efficacy of ARCEX Therapy to improve hand and arm functions in people living with cervical SCI. ClinicalTrials.gov identifier: NCT04697472 .

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

OBJECTIVE: To 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). DESIGN: Between-day exploratory analysis. SETTING: Research laboratory in a rehabilitation hospital PARTICIPANTS: PwMISCI (N=26). INTERVENTIONS: 3-day high-velocity MST. MAIN OUTCOME MEASURES: Overground WS, SL, SF, and WR measured during the 10-Meter Walk Test. RESULTS: Among 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%). CONCLUSIONS: On 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.

REPORT-SCS: minimum reporting standards for spinal cord stimulation studies in spinal cord injury.

Objective.Electrical spinal cord stimulation (SCS) has emerged as a promising therapy for recovery of motor and autonomic dysfunctions following spinal cord injury (SCI). Despite the rise in studies using SCS for SCI complications, there are no standard guidelines for reporting SCS parameters in research publications, making it challenging to compare, interpret or reproduce reported effects across experimental studies.Approach.To develop guidelines for minimum reporting standards for SCS parameters in pre-clinical and clinical SCI research, we gathered an international panel of expert clinicians and scientists. Using a Delphi approach, we developed guideline items and surveyed the panel on their level of agreement for each item.Main results.There was strong agreement on 26 of the 29 items identified for establishing minimum reporting standards for SCS studies. The guidelines encompass three major SCS categories: hardware, configuration and current parameters, and the intervention.Significance.Standardized reporting of stimulation parameters will ensure that SCS studies can be easily analyzed, replicated, and interpreted by the scientific community, thereby expanding the SCS knowledge base and fostering transparency in reporting.

Assessment of Dorsiflexion Ability across Tasks in Persons with Subacute SCI after Combined Locomotor Training and Transcutaneous Spinal Stimulation.

In people with spinal cord injury (SCI), transcutaneous spinal stimulation (TSS) has an immediate effect on the ability to dorsiflex the ankle, but persistent effects are not known. Furthermore, TSS has been associated with improved walking, increased volitional muscle activation, and decreased spasticity when combined with locomotor training (LT). In this study, the persistent impact of combined LT and TSS on dorsiflexion during the swing phase of walking and a volitional task in participants with SCI is determined. Ten participants with subacute motor-incomplete SCI received 2 weeks of LT alone (wash-in phase), followed by 2 weeks of either LT + TSS (TSS at 50 Hz) or LT + TSSSham (intervention phase). There was no persistent effect of TSS on dorsiflexion during walking and inconsistent effects on the volitional task. There was a strong positive correlation between the dorsiflexor ability for both tasks. There was a moderate effect of 4 weeks of LT on increased dorsiflexion during the task (d = 0.33) and walking (d = 0.34) and a small effect on spasticity (d = -0.2). Combined LT + TSS did not show persistent effects on dorsiflexion ability in people with SCI. Four weeks of locomotor training was associated with increased dorsiflexion across tasks. Improvements in walking observed with TSS may be due to factors other than improved ankle dorsiflexion.

Cost-effectiveness analysis of overground robotic training versus conventional locomotor training in people with spinal cord injury.

BACKGROUND: Few, if any estimates of cost-effectiveness for locomotor training strategies following spinal cord injury (SCI) are available. The purpose of this study was to estimate the cost-effectiveness of locomotor training strategies following spinal cord injury (overground robotic locomotor training versus conventional locomotor training) by injury status (complete versus incomplete) using a practice-based cohort. METHODS: A probabilistic cost-effectiveness analysis was conducted using a prospective, practice-based cohort from four participating Spinal Cord Injury Model System sites. Conventional locomotor training strategies (conventional training) were compared to overground robotic locomotor training (overground robotic training). Conventional locomotor training included treadmill-based training with body weight support, overground training, and stationary robotic systems. The outcome measures included the calculation of quality adjusted life years (QALYs) using the EQ-5D and therapy costs. We estimate cost-effectiveness using the incremental cost utility ratio and present results on the cost-effectiveness plane and on cost-effectiveness acceptability curves. RESULTS: Participants in the prospective, practice-based cohort with complete EQ-5D data (n = 99) qualified for the analysis. Both conventional training and overground robotic training experienced an improvement in QALYs. Only people with incomplete SCI improved with conventional locomotor training, 0.045 (SD 0.28), and only people with complete SCI improved with overground robotic training, 0.097 (SD 0.20). Costs were lower for conventional training, $1758 (SD $1697) versus overground robotic training $3952 (SD $3989), and lower for those with incomplete versus complete injury. Conventional overground training was more effective and cost less than robotic therapy for people with incomplete SCI. Overground robotic training was more effective and cost more than conventional training for people with complete SCI. The incremental cost utility ratio for overground robotic training for people with complete spinal cord injury was $12,353/QALY. CONCLUSIONS: The most cost-effective locomotor training strategy for people with SCI differed based on injury completeness. Conventional training was more cost-effective than overground robotic training for people with incomplete SCI. Overground robotic training was more cost-effective than conventional training for people with complete SCI. The effect estimates may be subject to limitations associated with small sample sizes and practice-based evidence methodology. These estimates provide a baseline for future research.

Accuracy of self-reported severity and level of spinal cord injury.

STUDY DESIGN: Observational. OBJECTIVES: To assess accuracy of self-reported level of injury (LOI) and severity in individuals with chronic spinal cord injury (SCI) as compared with clinical examination. SETTING: An SCI Model System Hospital. METHODS: A 20-item survey evaluated demographics, physical abilities, and self-reported injury level and severity. A decision tree algorithm used responses to categorize participants into injury severity groups. Following the survey, participants underwent clinical examination to determine current injury level and severity. Participants were later asked three questions regarding S1 sparing. Chart abstraction was utilized to obtain initial injury level and severity. Injury level and severity from self-report, decision tree, clinical exam, and chart abstraction were compared. RESULTS: Twenty-eight individuals participated. Ninety-three percent correctly self-reported anatomical region of injury (ROI). Self-report of specific LOI matched current clinical LOI for 25% of participants, but matched initial LOI for 61%. Self-report of ASIA Impairment Scale (AIS) matched clinical AIS for 36%, but matched initial AIS for 46%. The injury severity decision tree was 75% accurate without, but 79% accurate with additional S1 questions. Self-report of deep anal pressure (DAP) was correct for 86% of participants, while self-report of voluntary anal contraction (VAC) was correct for 82%. CONCLUSION: Individuals with SCI are more accurate reporting ROI than specific LOI. Self-reported injury level and severity align more closely with initial clinical examination results than current exam results. Using aggregate data from multiple questions can categorize injury severity more reliably than self-report. Using this type of decision tree may improve injury severity classification in large survey studies.

Walking and Balance Outcomes Are Improved Following Brief Intensive Locomotor Skill Training but Are Not Augmented by Transcranial Direct Current Stimulation in Persons With Chronic Spinal Cord Injury.

Motor training to improve walking and balance function is a common aspect of rehabilitation following motor-incomplete spinal cord injury (MISCI). Evidence suggests that moderate- to high-intensity exercise facilitates neuroplastic mechanisms that support motor skill acquisition and learning. Furthermore, enhancing corticospinal drive via transcranial direct current stimulation (tDCS) may augment the effects of motor training. In this pilot study, we investigated whether a brief moderate-intensity locomotor-related motor skill training (MST) circuit, with and without tDCS, improved walking and balance outcomes in persons with MISCI. In addition, we examined potential differences between within-day (online) and between-day (offline) effects of MST. Twenty-six adults with chronic MISCI, who had some walking ability, were enrolled in a 5-day double-blind, randomized study with a 3-day intervention period. Participants were assigned to an intensive locomotor MST circuit and concurrent application of either sham tDCS (MST+tDCSsham) or active tDCS (MST+tDCS). The primary outcome was overground walking speed measured during the 10-meter walk test. Secondary outcomes included spatiotemporal gait characteristics (cadence and stride length), peak trailing limb angle (TLA), intralimb coordination (ACC), the Berg Balance Scale (BBS), and the Falls Efficacy Scale-International (FES-I) questionnaire. Analyses revealed a significant effect of the MST circuit, with improvements in walking speed, cadence, bilateral stride length, stronger limb TLA, weaker limb ACC, BBS, and FES-I observed in both the MST+tDCSsham and MST+tDCS groups. No differences in outcomes were observed between groups. Between-day change accounted for a greater percentage of the overall change in walking outcomes. In persons with MISCI, brief intensive MST involving a circuit of ballistic, cyclic locomotor-related skill activities improved walking outcomes, and selected strength and balance outcomes; however, concurrent application of tDCS did not further enhance the effects of MST. Clinical Trial Registration: [ClinicalTrials.gov], identifier [NCT03237234].

A Pilot Study of Intensive Locomotor-Related Skill Training and Transcranial Direct Current Stimulation in Chronic Spinal Cord Injury.

BACKGROUND AND PURPOSE: Improved walking function is a priority among persons with motor-incomplete spinal cord injury (PwMISCI). Accessibility and cost limit long-term participation in locomotor training offered in specialized centers. Intensive motor training that facilitates neuroplastic mechanisms that support skill learning and can be implemented in the home/community may be advantageous for promoting long-term restoration of walking function. Additionally, increasing corticospinal drive via transcranial direct current stimulation (tDCS) may enhance training effects. In this pilot study, we investigated whether a moderate-intensity motor skill training (MST) circuit improved walking function in PwMISCI and whether augmenting training with tDCS influenced outcomes. METHODS: Twenty-five adults (chronic, motor-incomplete spinal cord injury) were randomized to a 3-day intervention of a locomotor-related MST circuit and concurrent application of sham tDCS (MST+tDCS sham ) or active tDCS (MST+tDCS). The primary outcome was overground walking speed. Secondary outcomes included walking distance, cadence, stride length, and step symmetry index (SI). RESULTS: Analyses revealed significant effects of the MST circuit on walking speed, walking distance, cadence, and bilateral stride length but no effect on interlimb SI. No significant between-groups differences were observed. Post hoc analyses revealed within-groups change in walking speed (ΔM = 0.13 m/s, SD = 0.13) that app-roached the minimally clinically important difference of 0.15 m/s. DISCUSSION AND CONCLUSIONS: Brief, intensive MST involving locomotor-related activities significantly increased walking speed, walking distance, and spatiotemporal measures in PwMISCI. Significant additive effects of tDCS were not observed; however, participation in only 3 days of MST was associated with changes in walking speed that were comparable to longer locomotor training studies.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A386 ).

Effects of whole-body vibration on neuropathic pain and the relationship between pain and spasticity in persons with spinal cord injury.

OBJECTIVE: Whole-body vibration (WBV) appears to modulate reflex hyperexcitability and spasticity. Due to common underlying neural mechanisms between spasticity and neuropathic pain, WBV may also reduce chronic pain after spinal cord injury (SCI). Our objective was to determine whether there are dose-related changes in pain following WBV and to examine the relationships between neuropathic pain and reflex excitability. STUDY DESIGN: Secondary analysis of a sub-population (participants with neuropathic pain, n = 16) from a larger trial comparing the effects of two different doses of WBV on spasticity in persons with SCI. SETTING: Hospital/Rehabilitation Center in Atlanta, GA, USA. METHODS: Participants were randomized to 8-bout or 16-bout WBV groups. Both groups received ten sessions of sham intervention, followed by ten sessions of WBV. Primary measures included the Neuropathic Pain Symptom Inventory (NPSI) for pain symptom severity and H-reflex paired-pulse depression (PPD) for reflex excitability. RESULTS: Mean change in NPSI scores were not significantly different between the groups (7 ± 6; p = 0.29; ES = 0.57); however, 8-bouts of WBV were consistently beneficial for participants with high neuropathic pain symptom severity (NPSI total score >30), while 16-bouts of WBV appeared to increase pain in some individuals with high NPSI scores. A baseline NPSI cut score of 30 predicted PPD response (sensitivity = 1.0, specificity = 0.83), with higher NPSI scores associated with decreased PPD in response to WBV. CONCLUSIONS: WBV in moderate doses appears to decrease neuropathic pain symptoms and improve reflex modulation. However, at higher doses neuropathic pain symptoms may be aggravated. Lower baseline NPSI scores were associated with improved reflex modulation.

Acceptability and impact on spasticity of a single session of upper extremity vibration in individuals with tetraplegia.

STUDY DESIGN: Pre-post design; before and after vibration intervention. OBJECTIVES: To explore effect of a focal, self-applied upper extremity (UE) vibration intervention on UE spasticity for individuals with tetraplegia. The secondary objectives were to explore the acceptability and ease of use of this intervention. SETTING: Specialty rehabilitation center in Georgia, USA. METHODS: Eleven participants each completed one session of focal, self-applied vibration to the UEs. UE spasticity was measured using the Modified Ashworth Scale (MAS). UE function was measured using the Box & Block (B&B) test which measures the effectiveness of grasp, transport, and release. These measurements were taken pre-intervention, immediately post-intervention, and 20 min post-intervention. Participants also self-reported the acceptability and usability of the intervention, their perception of change in their spasticity and completed the Qualities of Spasticity Questionnaire. RESULTS: In the full group analysis of the spasticity measures, no significant effects were found. Subgroup analysis, however, indicated participants with higher spasticity demonstrated significantly more change on the MAS than the lower spasticity group. Analysis did not reveal any impact of the intervention on UE function as measured by the B&B. Ten out of eleven participants indicated that they agreed or strongly agreed that the intervention would be valuable to have at home. CONCLUSIONS: Participants with higher spasticity demonstrated decreased spasticity after focal UE vibration, although there was no clear effect on grasp, transport and release function. Participants were satisfied with the intervention; most were able to use it independently and indicated it would be a valuable home intervention.

Commentary: Remote assessments of gait and balance - Implications for research during and beyond Covid-19.

The COVID-19 pandemic has disrupted non-essential in-person research activities that require contact with human subjects. While guidelines are being developed for ramping up human subjects research, one component of research that can be performed remotely is participant screening for lower limb function and gait impairments. In this commentary, we summarize evidence-supported clinical assessments that have potential to be conducted remotely in a safe manner, to make an initial determination of the functional mobility status of persons with neurological disorders. We present assessments that do not require complex or costly equipment, specialized software, or trained personnel to administer. We provide recommendations to implement remote functional assessments for participant recruitment and continuation of lower limb neurorehabilitation research as a rapid response to the COVID-19 pandemic and for utilization beyond the current pandemic. We also highlight critical research gaps related to feasibility and measurement characteristics of remote lower limb assessments, providing opportunities for future research to advance tele-assessment and tele-rehabilitation.

Characterizing the Experience of Spasticity after Spinal Cord Injury: A National Survey Project of the Spinal Cord Injury Model Systems Centers.

OBJECTIVE: To characterize the qualities that individuals with spinal cord injury (SCI) associate with their experience of spasticity and to describe the relationship between spasticity and perceived quality of life and the perceived value of spasticity management approaches. DESIGN: Online cross-sectional survey. SETTING: Multicenter collaboration among 6 Spinal Cord Injury Model Systems hospitals in the United States. PARTICIPANTS: Individuals with SCI (N=1076). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Qualities of Spasticity Questionnaire, modified Spinal Cord Injury-Spasticity Evaluation Tool (mSCI-SET), and the modified Patient-Reported Impact of Spasticity Measure (mPRISM). RESULTS: Respondents indicated that spasms most often occurred in response to movement-related triggering events. However, spontaneous spasms (ie, no triggering event) were also reported to be among the most common types. Frequency of spasms appears to decline with age. The highest frequency of spasms was reported by 56% of respondents aged <25 years and by only 28% of those >55 years. Stiffness associated with spasticity was reported to be more common than spasms (legs, 65% vs 54%; trunk, 33% vs 18%; arms, 26% vs 15%). Respondents reported negative effects of spasticity more commonly than positive effects. Based on their association with negative scores on the mSCI-SET and the mPRISM, the 5 most problematic experiences reported were stiffness all day, interference with sleep, painful spasms, perceived link between spasticity and pain, and intensification of pain before a spasm. Respondents indicated spasticity was improved more by stretching (48%) and exercise (45%) than by antispasmodics (38%). CONCLUSIONS: The experience of spasticity after SCI is complex and multidimensional, with consequences that affect mobility, sleep, comfort, and quality of life. Stiffness, rather than spasms, appears to be the most problematic characteristic of spasticity. Physical therapeutic interventions to treat spasticity warrant in-depth investigation.

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

OBJECTIVE: To 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. DESIGN: Cross-sectional, 1-5 days of data collection. SETTING: Community-based data collection. PARTICIPANTS: Adults with chronic (>1 year), motor incomplete SCI (N=27). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Ambulatory 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. RESULTS: The 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. CONCLUSIONS: The 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.

Predicting Duration of Outpatient Physical Therapy Episodes for Individuals with Spinal Cord Injury Based on Locomotor Training Strategy.

OBJECTIVE: To characterize individuals with spinal cord injuries (SCI) who use outpatient physical therapy or community wellness services for locomotor training and predict the duration of services, controlling for demographic, injury, quality of life, and service and financial characteristics. We explore how the duration of services is related to locomotor strategy. DESIGN: Observational study of participants at 4 SCI Model Systems centers with survival. Weibull regression model to predict the duration of services. SETTING: Rehabilitation and community wellness facilities at 4 SCI Model Systems centers. PARTICIPANTS: Eligibility criteria were SCI or dysfunction resulting in motor impairment and the use of physical therapy or community wellness programs for locomotor/gait training. We excluded those who did not complete training or who experienced a disruption in training greater than 45 days. Our sample included 62 participants in conventional therapy and 37 participants in robotic exoskeleton training. INTERVENTIONS: Outpatient physical therapy or community wellness services for locomotor/gait training. MAIN OUTCOME MEASURES: SCI characteristics (level and completeness of injury) and the duration of services from medical records. Self-reported perceptions of SCI consequences using the SCI-Functional Index for basic mobility and SCI-Quality of Life measurement system for bowel difficulties, bladder difficulties, and pain interference. RESULTS: After controlling for predictors, the duration of services for the conventional therapy group was an average of 63% longer than for the robotic exoskeleton group, however each visit was 50% shorter in total time. Men had an 11% longer duration of services than women had. Participants with complete injuries had a duration of services that was approximately 1.72 times longer than participants with incomplete injuries. Perceived improvement was larger in the conventional group. CONCLUSIONS: Locomotor/gait training strategies are distinctive for individuals with SCI using a robotic exoskeleton in a community wellness facility as episodes are shorter but individual sessions are longer. Participants' preferences and the ability to pay for ongoing services may be critical factors associated with the duration of outpatient services.

Noninvasive neuromodulation and rehabilitation to promote functional restoration in persons with spinal cord injury.

PURPOSE OF REVIEW: This review will focus on the use of clinically accessible neuromodulatory approaches for functional restoration in persons with spinal cord injury (SCI). RECENT FINDINGS: Functional restoration is a primary rehabilitation priority for individuals with SCI. High-tech neuromodulatory modalities have been used in laboratory settings to improve hand and walking function as well as to reduce spasticity and pain in persons with SCI. However, the cost, limited accessibility, and required expertise are prohibitive for clinical applicability of these high-tech modalities. Recent literature indicates that noninvasive and clinically accessible approaches targeting supraspinal, spinal, and peripheral neural structures can modulate neural excitability. Although a limited number of studies have examined the use of these approaches for functional restoration and amelioration of secondary complications in SCI, early evidence investigating their efficacy when combined with training is encouraging. SUMMARY: Larger sample studies addressing both biomarker identification and dosing are crucial next steps in the field of neurorehabilitation research before novel noninvasive stimulation approaches can be incorporated into standard clinical practice.

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.

The influence of physiologic and atmospheric variables on spasticity after spinal cord injury.

BACKGROUND: A number of physiological and atmospheric variables are believed to increase spasticity in persons with spinal cord injury (SCI) based on self-reported measures, however, there is limited objective evidence about the influence of these variables on spasticity. OBJECTIVE: We investigated the relationship between physiological/ atmospheric variables and level of spasticity in individuals with SCI. METHODS: In 53 participants with motor-incomplete SCI, we assessed the influence of age, time since injury, sex, injury severity, neurological level of injury, ability to walk, antispasmodic medication use, temperature, humidity, and barometric pressure on quadriceps spasticity. Spasticity was assessed using the pendulum test first swing excursion (FSE). To categorize participants based on spasticity severity, we performed cluster analysis. We used multivariate stepwise regression to determine variables associated with spasticity severity level. RESULTS: Three spasticity groups were identified based on spasticity severity level: low, moderate, and high. The regression analysis revealed that only walking ability and temperature were significantly related to spasticity severity. CONCLUSIONS: These outcomes validate the self-reported perception of people with SCI that low temperatures worsen spasticity. The findings refine prior evidence that people with motor-incomplete SCI have higher levels of spasticity, showing that those with sufficient motor function to walk have the highest levels of spasticity.

Combined Transcutaneous Spinal Stimulation and Locomotor Training to Improve Walking Function and Reduce Spasticity in Subacute Spinal Cord Injury: A Randomized Study of Clinical Feasibility and Efficacy.

Locomotor training (LT) is intended to improve walking function and can also reduce spasticity in motor-incomplete spinal cord injury (MISCI). Transcutaneous spinal stimulation (TSS) also influences these outcomes. We assessed feasibility and preliminary efficacy of combined LT + TSS during inpatient rehabilitation in a randomized, sham-controlled, pragmatic study. Eighteen individuals with subacute MISCI (2-6 months post-SCI) were enrolled and randomly assigned to the LT + TSS or the LT + TSSsham intervention group. Participants completed a 4-week program consisting of a 2-week wash-in period (LT only) then a 2-week intervention period (LT + TSS or LT + TSSsham). Before and after each 2-week period, walking (10 m walk test, 2-min walk test, step length asymmetry) and spasticity (pendulum test, clonus drop test, modified spinal cord injury-spasticity evaluation tool) were assessed. Sixteen participants completed the study. Both groups improved in walking speed and distance. While there were no significant between-groups differences, the LT + TSS group had significant improvements in walking outcomes following the intervention period; conversely, improvements in the LT + TSSsham group were not significant. Neither group had significant changes in spasticity, and the large amount of variability in spasticity may have obscured ability to observe change in these measures. TSS is a feasible adjunct to LT in the subacute stage of SCI and may have potential to augment training-related improvements in walking outcomes.

Meeting Proceedings for SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research.

The spinal cord injury (SCI) research community has experienced great advances in discovery research, technology development, and promising clinical interventions in the past decade. To build upon these advances and maximize the benefit to persons with SCI, the National Institutes of Health (NIH) hosted a conference February 12-13, 2019 titled "SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research." The purpose of the conference was to bring together a broad range of stakeholders, including researchers, clinicians and healthcare professionals, persons with SCI, industry partners, regulators, and funding agency representatives to break down existing communication silos. Invited speakers were asked to summarize the state of the science, assess areas of technological and community readiness, and build collaborations that could change the trajectory of research and clinical options for people with SCI. In this report, we summarize the state of the science in each of five key domains and identify the gaps in the scientific literature that need to be addressed to move the field forward.