Longitudinal Recovery and Reduced Costs After 120 Sessions of Locomotor Training for Motor Incomplete Spinal Cord Injury

A qualitative study of the perceived benefits of participating in a spinal cord rehabilitation intervention in a low-middle income country

PURPOSE

Improving quality of life (QoL) is a major goal of rehabilitation following spinal cord injury (SCI). However, people with disabilities in resource constrained contexts have limited access to rehabilitation and poorer health outcomes, including QoL. There is a paucity of qualitative research on the experiences of persons with SCI involved in rehabilitation programmes in low-middle income countries. This study aimed to assess participants' perceptions of the benefits of a 24-week SCI rehabilitation programme delivered as part of a pilot randomized controlled trial (RCT) in South Africa.

MATERIALS AND METHODS

Sixteen participants, with chronic motor-incomplete tetraplegia, were enrolled in a two-arm pilot RCT involving robotic locomotor training, a novel technology, and standard activity-based training (Pan African Clinical Trial Registry (PACTR201608001647143)). Data were collected via in-depth interviews and analysed using thematic analysis.

RESULTS

Participants described several improvements in QoL, including enhanced functional independence; reduced secondary complications; and improved psychosocial and emotional well-being.

CONCLUSIONS

The holistic approach to rehabilitation calls for the involvement of individuals' views about what matters to them to inform clinical practice and to highlight the role that physical activity and the perceived successes play in shaping the lived experiences after SCI.

TRIAL REGISTRATION

Pan African Clinical Trial Registry (PACTR201608001647143), registration date (21st May 2016), study start date (30th Nov 2016)https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1647.

Robotic locomotor training in a low-resource setting: a randomized pilot and feasibility trial

PURPOSE

Activity-based Training (ABT) represents the current standard of neurological rehabilitation. Robotic Locomotor Training (RLT), an innovative technique, aims to enhance rehabilitation outcomes. This study aimed to conduct a randomized pilot and feasibility trial of a locomotor training program within South Africa.

MATERIALS AND METHODS

Individuals with chronic traumatic motor incomplete tetraplegia (n = 16). Each intervention involved 60-minute sessions, 3x per week, for 24-weeks. Outcomes included feasibility measures and functional capacity.

RESULTS

17 out of 110 individuals initiated the program (recruitment rate = 15.4%) and 16 completed the program (drop-out rate = 5.8%) and attended sessions (attendance rate = 93.9%). Both groups showed a significant increase in upper extremity motor score (MS) and abdominal strength post intervention. Only the RLT group showed a significant change in lower extremity MS, with a mean increase of 3.00 [0.00; 16.5] points over time. Distance walked in the Functional Ambulatory Inventory (SCI-FAI) increased significantly (p = 0.02) over time only for the RLT group.

CONCLUSIONS

Feasibility rates of the intervention and functional outcomes justify a subsequent powered RCT comparing RLT to ABT as an effective rehabilitation tool for potentially improving functional strength and walking capacity in people with incomplete SCI.

Electrical stimulation of the cuneiform nucleus enhances the effects of rehabilitative training on locomotor recovery after incomplete spinal cord injury

Most human spinal cord injuries are anatomically incomplete, leaving some fibers still connecting the brain with the sublesional spinal cord. Spared descending fibers of the brainstem motor control system can be activated by deep brain stimulation (DBS) of the cuneiform nucleus (CnF), a subnucleus of the mesencephalic locomotor region (MLR). The MLR is an evolutionarily highly conserved structure which initiates and controls locomotion in all vertebrates. Acute electrical stimulation experiments in female adult rats with incomplete spinal cord injury conducted in our lab showed that CnF-DBS was able to re-establish a high degree of locomotion five weeks after injury, even in animals with initially very severe functional deficits and white matter lesions up to 80-95%. Here, we analyzed whether CnF-DBS can be used to support medium-intensity locomotor training and long-term recovery in rats with large but incomplete spinal cord injuries. Rats underwent rehabilitative training sessions three times per week in an enriched environment, either with or without CnF-DBS supported hindlimb stepping. After 4 weeks, animals that trained under CnF-DBS showed a higher level of locomotor performance than rats that trained comparable distances under non-stimulated conditions. The MLR does not project to the spinal cord directly; one of its main output targets is the gigantocellular reticular nucleus in the medulla oblongata. Long-term electrical stimulation of spared reticulospinal fibers after incomplete spinal cord injury via the CnF could enhance reticulospinal anatomical rearrangement and in this way lead to persistent improvement of motor function. By analyzing the spared, BDA-labeled giganto-spinal fibers we found that their gray matter arborization density after discontinuation of CnF-DBS enhanced training was lower in the lumbar L2 and L5 spinal cord in stimulated as compared to unstimulated animals, suggesting improved pruning with stimulation-enhanced training. An on-going clinical study in chronic paraplegic patients investigates the effects of CnF-DBS on locomotor capacity.

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

Background

After spinal cord injury (SCI), inpatient rehabilitation begins and continues through outpatient therapy. Overground exoskeleton gait training (OEGT) has been shown to be feasible in both settings, yet its use as an intervention across the continuum has not yet been reported.

Objectives

This study describes OEGT for patients with SCI across the continuum and its effects on clinical outcomes.

Methods

Medical records of patients with SCI who completed at least one OEGT session during inpatient and outpatient rehabilitation from 2018 to 2021 were retrospectively reviewed. Demographic data, Walking Index for Spinal Cord Injury-II (WISCI-II) scores, and OEGT session details (frequency, "walk" time, "up" time, and step count) were extracted.

Results

Eighteen patients [male (83%), White (61%), aged 37.4 ± 15 years, with tetraplegia (50%), American Spinal Injury Association Impairment Scale A (28%), B (22%), C (39%), D (11%)] completed OEGT sessions (motor complete, 18.2 ± 10.3; motor incomplete, 16.7 ± 7.7) over approximately 18 weeks (motor complete, 15.1 ± 6.4; motor incomplete, 19.0 ± 8.2). Patients demonstrated improved OEGT session tolerance on device metrics including "walk" time (motor complete, 7:51 ± 4:42 to 24:50 ± 9:35 minutes; motor incomplete, 12:16 ± 6:01 to 20:01 ± 08:05 minutes), "up" time (motor complete, 16:03 ± 7:41 to 29:49 ± 12:44 minutes; motor incomplete, 16:38 ± 4:51 to 23:06 ± 08:50 minutes), and step count (motor complete, 340 ± 295.9 to 840.2 ± 379.4; motor incomplete, 372.3 ± 225.2 to 713.2 ± 272). Across therapy settings, patients with motor complete SCI experienced improvement in WISCI-II scores from 0 ± 0 at inpatient admission to 3 ± 4.6 by outpatient discharge, whereas the motor incomplete group demonstrated a change of 0.2 ± 0.4 to 9.0 ± 6.4.

Conclusion

Patients completed OEGT across the therapy continuum. Patients with motor incomplete SCI experienced clinically meaningful improvements in walking function.

Providing Insights into the Challenges of Implementing Activity-Based Therapy in Canada: A Comparative Analysis Using Focus Group Interviews with Key Interest Groups

Background

Activity-based therapy (ABT) has emerged as a therapeutic approach that may promote neurorecovery and reduce secondary complications in people living with spinal cord injury or disease (SCI/D). In spite of the numerous health benefits, adoption of ABT into practice has been limited across the Canadian care continuum.

Objectives

This study aimed to understand the challenges of implementing ABT in Canada for people living with SCI/D through the perspectives of key interest groups.

Methods

Researchers, hospital therapists, community trainers, administrators, persons living with SCI/D, and advocates, funders, and policy experts who had knowledge of and/or experience with ABT participated in focus group interviews to share their perspectives on the barriers to ABT practice. Interviews were analyzed using conventional content analysis followed by a comparative analysis across groups.

Results

The 48 participants identified six key challenges: (1) challenge of gaps in knowledge/training, (2) challenge of standardizing ABT, (3) challenge of determining the optimal timing of ABT, (4) challenge of defining, characterizing, and achieving high dosage and intensity, (5) challenge of funding ABT, and (6) challenge of measuring participation and performance in ABT. A comparative analysis found some challenges were emphasized by certain groups, such as the cost of ABT for persons with SCI/D, lack of education and training in ABT for therapists and trainers, minimal evidence to develop guidelines for researchers and advocates, and funding ABT programs for administrators.

Conclusion

Participants highlighted several challenges that limit ABT practice. Strategies to address these challenges will support successful implementation of ABT in Canada.

Challenges in Translating Regenerative Therapies for Spinal Cord Injury

Regenerating the injured spinal cord is a substantial challenge with many obstacles that need to be overcome to achieve robust functional benefits. This abundance of hurdles can partly explain the limited success when applying regenerative intervention treatments in animal models and/or people. In this article, we elaborate on a few of these obstacles, starting with the applicability of animal models and how they compare to the clinical setting. We then discuss the requirement for combinatorial interventions and the associated problems in experimental design, including the addition of rehabilitative training. The article expands on differences in lesion sizes and locations between humans and common animal models, and how this difference can determine the success or failure of an intervention. An additional and frequently overlooked problem in the translation of interventions that applies beyond the field of neuroregeneration is the reporting bias and the lack of transparency in reporting findings. New data mandates are tackling this problem and will eventually result in a more balanced view of the field. Finally, we will discuss strategies to negotiate the challenging course of successful translation to facilitate successful translation of regeneration promoting interventions.

Influence of Locomotion Therapy With the Wearable Cyborg HAL on Bladder and Bowel Function in Acute and Chronic SCI Patients

STUDY DESIGN

Retrospective survey.

OBJECTIVES

Purpose of this study was to explore whether bowel and bladder management can be influenced by locomotion therapy with HAL Robot Suit.

METHODS

35 subjects with acute (< one year since injury, n = 13) or chronic (> one year since injury, n = 22) incomplete paraplegia (American Spinal Injury Association Impairment Scale (AIS) B, n = 1 / AIS C, n = 22 / AIS D, n = 7) or complete paraplegia (AIS A, n = 5) with zones of partial preservation (ZPP) participated. A retrospective survey was carried out asking for bowel incontinence (Wexner Score), constipation (Cleveland Clinic Constipation Scoring System (CCCS)) and bladder function (self-developed questionnaire) before and after completing a training period of 12 weeks with HAL.

RESULTS

Wexner Score over all patients and for group of chronic patients decreased significantly. For group of acute patients Wexner Score decreased insignificantly. Patients from both groups with higher baseline scores could decrease significantly. CCCS was insignificantly reduced for all patients, group of acute and group of chronic patients. For subgroup of chronic patients with higher baseline scores, CCCS decreased at end of training period missing out significance. The self-developed questionnaire showed an improvement in bladder function in 28.24% of all patients, 31.43% of chronic patients, and 23.08% of acute patients.

CONCLUSIONS

Our findings show trends of enhanced bladder and bowel function following exoskeleton training. Patients with higher baseline scores in Wexner Score and CCCS seem to benefit more than those with mild to moderate scores.

Views of health care users and providers: Solutions to improve the prevention of secondary health conditions among people with spinal cord injury, South Africa

Study design

Explorative- qualitative study.

Objective

This study explored solutions to improve the prevention of secondary health conditions in people with spinal cord injury.

Setting

Rehabilitation hospital, South Africa.

Methods

Face to face semi-structured interviews were conducted with 21 therapists and 17 people with spinal cord injury at a public rehabilitation hospital. All the interviews were transcribed verbatim. Content analysis was conducted on the transcripts to identify proposed solutions to improve the prevention of secondary health conditions.

Results

The main theme that emerged was access to adequate health care. The categories linked to the main theme were: availability of health services, patient-centred care, strengthening rehabilitation care, access to resources and training health professionals.

Conclusions

Access to adequate health is central to preventing and managing secondary health conditions. Care for people with spinal cord injury needs to be empowering and address rehabilitation care needs across the lifespan. The proposed solutions will inform the development of a prevention care model for secondary health conditions in people with spinal cord injury.

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.

Is Graphene Shortening the Path toward Spinal Cord Regeneration?

Along with the development of the next generation of biomedical platforms, the inclusion of graphene-based materials (GBMs) into therapeutics for spinal cord injury (SCI) has potential to nourish topmost neuroprotective and neuroregenerative strategies for enhancing neural structural and physiological recovery. In the context of SCI, contemplated as one of the most convoluted challenges of modern medicine, this review first provides an overview of its characteristics and pathophysiological features. Then, the most relevant ongoing clinical trials targeting SCI, including pharmaceutical, robotics/neuromodulation, and scaffolding approaches, are introduced and discussed in sequence with the most important insights brought by GBMs into each particular topic. The current role of these nanomaterials on restoring the spinal cord microenvironment after injury is critically contextualized, while proposing future concepts and desirable outputs for graphene-based technologies aiming to reach clinical significance for SCI.

A Scoping Review of the Characteristics of Activity-based Therapy Interventions Across the Continuum of Care for People Living With Spinal Cord Injury or Disease

Objective

To identify the characteristics of activity-based therapy (ABT) that individuals with spinal cord injury and disease (SCI/D) participate in across the continuum of care.

Data Sources

A search of 8 databases was conducted from inception to 4 March 2020: Medline, CINAHL, Embase, Emcare, PEDro, APA PsycINFO, Cochrane Database of Systematic Reviews, and the CENTRAL. The search strategy used terms identifying the population (SCI/D) and concept (ABT).

Study Selection

Original studies involving individuals with SCI/D ≥16 years of age participating in ABT interventions for >1 session were included in the review. The Joanna Briggs Institute guidelines for scoping reviews were followed. The initial search produced 2306 records. Title, abstract, and full-text screening by 2 independent reviewers yielded 140 articles.

Data Extraction

Data extraction was conducted by 3 independent reviewers and charted according to key themes. Data fields included participant demographics, ABT interventions, exercises, parameters, technology, and setting. Data synthesis included frequency counts and descriptive analysis of key themes.

Data Synthesis

Eighty percent of participants were male. Eighty-seven percent of studies included individuals with tetraplegia (26% exclusive). Fifty-six percent of studies occurred in a research lab. Fifty-four percent of studies were single modality interventions encompassing the whole body (71%). Sixteen main types of ABT exercises were identified. The most common were treadmill training (59%), muscle strengthening (36%), and overground walking (33%). Electrical stimulation (50%) and virtual reality (6%) were used in combination with an ABT exercise. Eighty-four types of parameters were identified. Six were general intervention parameters and 78 were specific to the type of ABT exercise. Sixteen main categories of technology were reported. The most common were motorized treadmills (47%) and transcutaneous electrical stimulation (44%).

Conclusions

The characteristics of ABT are diverse in scope. The results will inform the content to include in tools that track ABT participation and performance.

Development and Application of Three-Dimensional Bioprinting Scaffold in the Repair of Spinal Cord Injury

Spinal cord injury (SCI) is a disabling and destructive central nervous system injury that has not yet been successfully treated at this stage. Three-dimensional (3D) bioprinting has become a promising method to produce more biologically complex microstructures, which fabricate living neural constructs with anatomically accurate complex geometries and spatial distributions of neural stem cells, and this is critical in the treatment of SCI. With the development of 3D printing technology and the deepening of research, neural tissue engineering research using different printing methods, bio-inks, and cells to repair SCI has achieved certain results. Although satisfactory results have not yet been achieved, they have provided novel ideas for the clinical treatment of SCI. Considering the potential impact of 3D bioprinting technology on neural studies, this review focuses on 3D bioprinting methods widely used in SCI neural tissue engineering, and the latest technological applications of bioprinting of nerve tissues for the repair of SCI are discussed. In addition to introducing the recent progress, this work also describes the existing limitations and highlights emerging possibilities and future prospects in this field.

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+tDCS_sham) 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+tDCS_sham 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.

Developing Peri-Operative Rehabilitation in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 6]: An Unexplored Opportunity?

STUDY DESIGN

Narrative review.

OBJECTIVE

Degenerative cervical myelopathy is one of the most frequent impairments of the spinal cord encountered internationally in adults. Currently, surgical decompression is the recommended treatment for people with DCM (PwCM) presenting with moderate to severe symptoms or neurological deficits. However, despite surgical intervention, not all patients make a complete recovery due to the irreversible tissue damage within the spinal cord. The objective of this review is to describe the state and gaps in the current literature on rehabilitation for PwCM and possible innovative rehabilitation strategies.

METHODS

Literature search.

RESULTS

In other neurological disorders such as stroke and acute traumatic spinal cord injury (SCI), timely and strategic rehabilitation has been shown to be indispensable for maximizing functional outcomes, and it is imperative that appropriate perioperative rehabilitative interventions accompany surgical approaches in order to enable the best outcomes. In this review, the current state of knowledge regarding rehabilitation for PwCM is described. Additionally, various therapies that have shown to improve outcomes in comparable neurological conditions such as stroke and SCI which may be translated to DCM will be reviewed.

CONCLUSIONS

We conclude that locomotor training and arm/hand therapy may benefit PwCM. Further, we conclude that body weight support, robotic assistance, and virtual/augmented reality therapies may be beneficial therapeutic analogs to locomotor and hand therapies.

Phase 1 Safety Trial of Autologous Human Schwann Cell Transplantation in Chronic Spinal Cord Injury

A phase 1 open-label, non-randomized clinical trial was conducted to determine feasibility and safety of autologous human Schwann cell (ahSC) transplantation accompanied by rehabilitation in participants with chronic spinal cord injury (SCI). Magnetic resonance imaging (MRI) was used to screen eligible participants to estimate an individualized volume of cell suspension to be implanted. The trial incorporated standardized multi-modal rehabilitation before and after cell delivery. Participants underwent sural nerve harvest, and ahSCs were isolated and propagated in culture. The dose of culture-expanded ahSCs injected into the chronic spinal cord lesion of each individual followed a cavity-filling volume approach. Primary outcome measures for safety and trend-toward efficacy were assessed. Two participants with American Spinal Injury Association Impairment Scale (AIS) A and two participants with incomplete chronic SCI (AIS B, C) were each enrolled in cervical and thoracic SCI cohorts (n = 8 total). All participants completed the study per protocol, and no serious adverse events related to sural nerve harvest or ahSC transplantation were reported. Urinary tract infections and skin abrasions were the most common adverse events reported. One participant experienced a 4-point improvement in motor function, a 6-point improvement in sensory function, and a 1-level improvement in neurological level of injury. Follow-up MRI in the cervical (6 months) and thoracic (24 months) cohorts revealed a reduction in cyst volume after transplantation with reduced effect over time. This phase 1 trial demonstrated the feasibility and safety of ahSC transplantation combined with a multi-modal rehabilitation protocol for participants with chronic SCI.

Eccentric rehabilitation induces white matter plasticity and sensorimotor recovery in chronic spinal cord injury

Experience-dependent white matter plasticity offers new potential for rehabilitation-induced recovery after neurotrauma. This first-in-human translational experiment combined myelin water imaging in humans and genetic fate-mapping of oligodendrocyte lineage cells in mice to investigate whether downhill locomotor rehabilitation that emphasizes eccentric muscle actions promotes white matter plasticity and recovery in chronic, incomplete spinal cord injury (SCI). In humans, of 20 individuals with SCI that enrolled, four passed the imaging screen and had myelin water imaging before and after a 12-week (3 times/week) downhill locomotor treadmill training program (SCI + DH). One individual was excluded for imaging artifacts. Uninjured control participants (n = 7) had two myelin water imaging sessions within the same day. Changes in myelin water fraction (MWF), a histopathologically-validated myelin biomarker, were analyzed in a priori motor learning and non-motor learning brain regions and the cervical spinal cord using statistical approaches appropriate for small sample sizes. PDGFRα-CreER^T2:mT/mG mice, that express green fluorescent protein on oligodendrocyte precursor cells and subsequent newly-differentiated oligodendrocytes upon tamoxifen-induced recombination, were either naive (n = 6) or received a moderate (75 kilodyne), contusive SCI at T9 and were randomized to downhill training (n = 6) or unexercised groups (n = 6). We initiated recombination 29 days post-injury, seven days prior to downhill training. Mice underwent two weeks of daily downhill training on the same 10% decline grade used in humans. Between-group comparison of functional (motor and sensory) and histological (oligodendrogenesis, oligodendroglial/axon interaction, paranodal structure) outcomes occurred post-training. In humans with SCI, downhill training increased MWF in brain motor learning regions (postcentral, precuneus) and mixed motor and sensory tracts of the ventral cervical spinal cord compared to control participants (P < 0.05). In mice with thoracic SCI, downhill training induced oligodendrogenesis in cervical dorsal and lateral white matter, increased axon-oligodendroglial interactions, and normalized paranodal structure in dorsal column sensory tracts (P < 0.05). Downhill training improved sensorimotor recovery in mice by normalizing hip and knee motor control and reducing hyperalgesia, both of which were associated with new oligodendrocytes in the cervical dorsal columns (P < 0.05). Our findings indicate that eccentric-focused, downhill rehabilitation promotes white matter plasticity and improved function in chronic SCI, likely via oligodendrogenesis in nervous system regions activated by the training paradigm. Together, these data reveal an exciting role for eccentric training in white matter plasticity and sensorimotor recovery after SCI.

Utility and Feasibility of Transcutaneous Spinal Cord Stimulation for Patients With Incomplete SCI in Therapeutic Settings: A Review of Topic

Transcutaneous Spinal Cord Stimulation (TSCS) has been shown to enhance the excitability of spinal neural circuits. This excitation is associated with enhanced voluntary performance in patients with incomplete SCI (iSCI). Though there is much we do not know, combining this altered state of exciability with therapy has the potential to enhance the outcomes associated with activity-based interventions. It is a promising tool to augment the work being done in therapeutic settings with the potential to expedite recovery. There is, however, a lag in assimilating the science for clinical practice. This article will examine current literature related to the application of TSCS in combination with therapeutic interventions for motor recovery and aims to elucidate trends in waveform selection, duration and frequency, and combinatorial therapies that may inform clinical practice. With specific consideration for therapeutic settings, potential benefits, applications, and pitfalls for clinical use are considered. Finally, the next steps in research to move toward wider clinical utility are discussed.

Activity-based therapy in the community for individuals living with spinal cord injury or disease: qualitative interviews with clinicians

PURPOSE

Activity-based therapy (ABT) is a restorative approach that promotes neurological recovery below the level of injury in individuals with spinal cord injury or disease (SCI/D). This study sought to understand how ABT and its associated technologies were being used in community-based facilities across Canada.

METHODS

One to two participants from ten community-based ABT facilities completed a semi-structured interview that queried types of technologies or techniques used in ABT, and barriers and facilitators to providing ABT for individuals with SCI/D. Interviews were audio-recorded and transcribed verbatim, and analyzed using an interpretive description approach to identify themes and categories.

RESULTS

The overarching theme that emerged was that ABT in the community is a client-centered approach characterized by variety in techniques, clinicians, and clientele. The researchers identified three categories within this theme: characteristics of ABT in the community, perceived challenges, and a need for advocacy. Participants advocated for earlier implementation, increased education, and reduced costs of ABT to address the challenges with implementation and accessibility.

CONCLUSIONS

The use of ABT and its associated technologies varied across participating community-based facilities in Canada, despite a consistent focus on client goals and well-being. Addressing system-level limitations of ABT may improve implementation and accessibility in Canada.Implications for rehabilitationActivity-based therapy (ABT) is a group of interventions targeting recovery of sensory and motor function below the level of injury in individuals with spinal cord injury or disease (SCI/D).ABT in the community emphasizes a client-centered approach and is characterized by variety in techniques, clinicians, and clientele.Participants advocated that earlier implementation, reduced costs, and increased education will help overcome barriers to providing ABT, ultimately assisting to facilitate neurorecovery in individuals with SCI/D.Challenges in implementation, accessibility, and knowledge of ABT exist, highlighting a need to explore and address system-level limitations in Canada.

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.

Exercise-Induced Plasticity in Signaling Pathways Involved in Motor Recovery after Spinal Cord Injury

Spinal cord injury (SCI) leads to numerous chronic and debilitating functional deficits that greatly affect quality of life. While many pharmacological interventions have been explored, the current unsurpassed therapy for most SCI sequalae is exercise. Exercise has an expansive influence on peripheral health and function, and by activating the relevant neural pathways, exercise also ameliorates numerous disorders of the central nervous system (CNS). While the exact mechanisms by which this occurs are still being delineated, major strides have been made in the past decade to understand the molecular underpinnings of this essential treatment. Exercise rapidly and prominently affects dendritic sprouting, synaptic connections, neurotransmitter production and regulation, and ionic homeostasis, with recent literature implicating an exercise-induced increase in neurotrophins as the cornerstone that binds many of these effects together. The field encompasses vast complexity, and as the data accumulate, disentangling these molecular pathways and how they interact will facilitate the optimization of intervention strategies and improve quality of life for individuals affected by SCI. This review describes the known molecular effects of exercise and how they alter the CNS to pacify the injury environment, increase neuronal survival and regeneration, restore normal neural excitability, create new functional circuits, and ultimately improve motor function following SCI.

The Effect of Exoskeletal-Assisted Walking on Spinal Cord Injury Bowel Function: Results from a Randomized Trial and Comparison to Other Physical Interventions

Bowel function after spinal cord injury (SCI) is compromised because of a lack of voluntary control and reduction in bowel motility, often leading to incontinence and constipation not easily managed. Physical activity and upright posture may play a role in dealing with these issues. We performed a three-center, randomized, controlled, crossover clinical trial of exoskeletal-assisted walking (EAW) compared to usual activity (UA) in people with chronic SCI. As a secondary outcome measure, the effect of this intervention on bowel function was assessed using a 10-question bowel function survey, the Bristol Stool Form Scale (BSS) and the Spinal Cord Injury Quality of Life (SCI-QOL) Bowel Management Difficulties instrument. Fifty participants completed the study, with bowel data available for 49. The amount of time needed for the bowel program on average was reduced in 24% of the participants after EAW. A trend toward normalization of stool form was noted. There were no significant effects on patient-reported outcomes for bowel function for the SCI-QOL components, although the time since injury may have played a role. Subset analysis suggested that EAW produces a greater positive effect in men than women and may be more effective in motor-complete individuals with respect to stool consistency. EAW, along with other physical interventions previously investigated, may be able to play a previously underappreciated role in assisting with SCI-related bowel dysfunction.

Effects of Exercise-Based Interventions on Urogenital Outcomes in Persons with Spinal Cord Injury: A Systematic Review and Meta-Analysis

In this systematic review, objectives were to investigate dropout rates, adverse events, and effects of exercise-based therapies on urogenital function and quality of life (QoL) in persons with spinal cord injury (SCI). Database searches were conducted on MEDLINE, EMBASE, and CINAHL for studies examining any form of exercise intervention on urogenital function and/or QoL in adults with SCI. Quality of publications was evaluated using the Joanna Briggs Institute critical evaluation tools. When possible, Hedges' g was calculated for overall effect sizes. Subgroup analyses were conducted on sex and injury severity. Ten studies (228 participants) were included in this review. Three studies examined pelvic floor muscle training, and seven studies examined locomotor training. Overall quality of evidence was low because of small sample sizes and non-randomized designs in most studies. Dropout rates ranged from 12% to 25%, and adverse events were reported only in some studies investigating locomotor training. For lower urinary tract (LUT) outcomes, urodynamic findings were mixed despite moderately positive changes in maximum bladder capacity (g = 0.50) and bladder compliance (g = 0.37). Fairly consistent, but small, improvements were observed in LUT symptoms, primarily bladder awareness and incontinence. LUT QoL improved in most cases. Fewer data were available for sexual outcomes, and only minor improvements were reported. Subgroup analyses, based on sex and severity of injury, were inconclusive. There is some indication for the potential benefit of exercise on urogenital outcomes in persons with SCI, but there is insufficient evidence given the number of studies and heterogeneity of outcome measures.

Perspectives of people living with a spinal cord injury on activity-based therapy

PURPOSE

Activity-Based Therapy (ABT) targets recovery of function below the injury level in individuals with spinal cord injury (SCI). This qualitative study is the first to capture the perspectives of individuals with SCI on community ABT programs in Canada.

METHODS

Ten participants (6 males, aged 23.0-65.0 years, 2.5-23.0 years post-SCI) were recruited using purposive sampling, and completed semi-structured interviews. Interview questions explored benefits and challenges, facilitators and barriers to access, and motivations for participating in ABT. Themes were identified using conventional content analysis and collaboratively analyzed using the DEPICT model.

RESULTS

An overarching theme of ABT as a key part of participants' evolving and lifelong recovery process emerged. Motivations for initiating ABT included dissatisfaction with early rehabilitation, and a desire to improve function and stay active. Participants perceived that ABT contributed to neurological recovery, physical and mental health benefits, independence, and hope. Factors contributing to recovery and factors limiting accessibility and participation in ABT were identified. Participants discussed advocating for ABT, and how ABT empowered self-management.

CONCLUSIONS

ABT was perceived to play a significant role in promoting ongoing recovery and well-being in individuals with SCI. Addressing limitations in awareness and availability of ABT may improve participation in ABT programs.Implications for rehabilitationActivity-Based Therapy (ABT) targets recovery of function and sensation below the level of injury in individuals with spinal cord injury (SCI).ABT plays a key role in the evolving and lifelong recovery process of individuals with SCI.Participants reported that ABT has a positive impact on physical, functional, and psychosocial domains, leading to improved independence and quality of life.Awareness and availability of ABT remain limited, highlighting a need to further explore and address factors limiting access to this therapy.

Novel velocity estimation for symmetric and asymmetric self-paced treadmill training

Background

Self-paced treadmills (SPT) can provide an engaging setting for gait rehabilitation by responding directly to the user’s intent to modulate the external environment and internal effort. They also can improve gait analyses by allowing scientists and clinicians to directly measure the effect of an intervention on walking velocity. Unfortunately, many common SPT algorithms are not suitable for individuals with gait impairment because they are designed for symmetric gait patterns. When the user’s gait is asymmetric due to paresis or if it contains large accelerations, the performance is diminished. Creating and validating an SPT that is suitable for asymmetric gait will improve our ability to study rehabilitation interventions in populations with gait impairment. The objective of this study was to test and validate a novel self-paced treadmill on both symmetric and asymmetric gait patterns and evaluate differences in gait kinematics, kinetics, and muscle activity between fixed-speed and self-paced treadmill walking.

Methods

We collected motion capture, ground reaction force data, and muscle activity from 6 muscles in the dominant leg during walking from 8 unimpaired subjects. In the baseline condition, the subjects walked at 3 fixed-speeds normalized to their leg length as Froude numbers. We developed a novel kinematic method for increasing the accuracy of the user’s estimated walking velocity and compared our method against other published algorithms at each speed. Afterward, subjects walked on the SPT while matching their walking speed to a given target velocity using visual feedback of the treadmill speed. We evaluated the SPT by measuring steady-state error and the number of steps to reach the desired speed. We split the gait cycle into 7 phases and compared the kinematic, kinetic, and muscle activity between the fixed speed and self-paced mode in each phase. Then, we validated the performance of the SPT for asymmetric gait by having subjects walk on the SPT while wearing a locked-knee brace set to 0° on the non-dominant leg.

Results

Our SPT enabled controlled walking for both symmetric and asymmetric gait patterns. Starting from rest, subjects were able to control the SPT to reach the targeted speeds using visual feedback in 13–21 steps. With the locked knee brace, subjects controlled the treadmill with substantial step length and step velocity asymmetry. One subject was able to execute a step-to gait and halt the treadmill on heel-strikes with the braced leg. Our kinematic correction for step-length outperformed the competing algorithms by significantly reducing the velocity estimation error at the tested velocities. The joint kinematics, joint torques, and muscle activity were generally similar between fixed-speed and self-paced walking. Statistically significant differences were found in 5 of 63 tests for joint kinematics, 2 of 63 tests for joint torques, and 9 of 126 tests for muscle activity. The differences that were statistically significant were not found across all speeds and were generally small enough to be of limited clinical relevance.

Conclusions

We present a validated method for implementing a self-paced treadmill for asymmetric and symmetric gaits. As a result of the increased accuracy of our estimation algorithm, our SPT produced controlled walking without including a position feedback controller, thereby reducing the influence of the controller on measurements of the user’s true walking speed. Our method relies only on a kinematic correction to step length and step time which can support transfer to systems outside of the laboratory for symmetric and asymmetric gaits in clinical populations.

Improvements in Bladder Function Following Activity-Based Recovery Training With Epidural Stimulation After Chronic Spinal Cord Injury

Spinal cord injury (SCI) results in profound neurologic impairment with widespread deficits in sensorimotor and autonomic systems. Voluntary and autonomic control of bladder function is disrupted resulting in possible detrusor overactivity, low compliance, and uncoordinated bladder and external urethral sphincter contractions impairing storage and/or voiding. Conservative treatments managing neurogenic bladder post-injury, such as oral pharmacotherapy and catheterization, are important components of urological surveillance and clinical care. However, as urinary complications continue to impact long-term morbidity in this population, additional therapeutic and rehabilitative approaches are needed that aim to improve function by targeting the recovery of underlying impairments. Several human and animal studies, including our previously published reports, have documented gains in bladder function due to activity-based recovery strategies, such as locomotor training. Furthermore, epidural stimulation of the spinal cord (scES) combined with intense activity-based recovery training has been shown to produce volitional lower extremity movement, standing, as well as improve the regulation of cardiovascular function. In our center, several participants anecdotally reported improvements in bladder function as a result of training with epidural stimulation configured for motor systems. Thus, in this study, the effects of activity-based recovery training in combination with scES were tested on bladder function, resulting in improvements in overall bladder storage parameters relative to a control cohort (no intervention). However, elevated blood pressure elicited during bladder distention, characteristic of autonomic dysreflexia, was not attenuated with training. We then examined, in a separate, large cross-sectional cohort, the interaction between detrusor pressure and blood pressure at maximum capacity, and found that the functional relationship between urinary bladder distention and blood pressure regulation is disrupted. Regardless of one’s bladder emptying method (indwelling suprapubic catheter vs. intermittent catheterization), autonomic instability can play a critical role in the ability to improve bladder storage, with SCI enhancing the vesico-vascular reflex. These results support the role of intersystem stimulation, integrating scES for both bladder and cardiovascular function to further improve bladder storage.

Corticospinal and spinal adaptations to motor skill and resistance training: Potential mechanisms and implications for motor rehabilitation and athletic development

Optimal strategies for enhancing strength and improving motor skills are vital in athletic performance and clinical rehabilitation. Initial increases in strength and the acquisition of new motor skills have long been attributed to neurological adaptations. However, early increases in strength may be predominantly due to improvements in inter-muscular coordination rather than the force-generating capacity of the muscle. Despite the plethora of research investigating neurological adaptations from motor skill or resistance training in isolation, little effort has been made in consolidating this research to compare motor skill and resistance training adaptations. The findings of this review demonstrated that motor skill and resistance training adaptations show similar short-term mechanisms of adaptations, particularly at a cortical level. Increases in corticospinal excitability and a release in short-interval cortical inhibition occur as a result of the commencement of both resistance and motor skill training. Spinal changes show evidence of task-specific adaptations from the acquired motor skill, with an increase or decrease in spinal reflex excitability, dependant on the motor task. An increase in synaptic efficacy of the reticulospinal projections is likely to be a prominent mechanism for driving strength adaptations at the subcortical level, though more research is needed. Transcranial electric stimulation has been shown to increase corticospinal excitability and augment motor skill adaptations, but limited evidence exists for further enhancing strength adaptations from resistance training. Despite the logistical challenges, future work should compare the longitudinal adaptations between motor skill and resistance training to further optimise exercise programming.

Hydrogels as delivery systems for spinal cord injury regeneration

Spinal cord injury is extremely debilitating, both at physiological and psychological levels, changing completely the patient's lifestyle. The introduction of biomaterials has opened a new window to develop a therapeutic approach to induce regeneration after injury due to similarities with extracellular matrix. Particularly, hydrogels have the ability to support axonal growth and endogenous regeneration. Moreover, they can also act as potential matrixes in which to load and deliver therapeutic agents at injury site. In this review, we highlight some important characteristics to be considered when designing hydrogels as delivery systems (DS), such as rheology, mesh size, swelling, degradation, gelation temperature and surface charge. Additionally, affinity-based release systems, incorporation of nanoparticles, or ion-mediated interactions are also pondered. Overall, hydrogel DS aim to promote a sustained, controlled and prolonged release at injury site, allowing a targeted oriented action of the therapeutic agent that will be used.

Feasibility and utility of transcutaneous spinal cord stimulation combined with walking-based therapy for people with motor incomplete spinal cord injury

STUDY DESIGN

Prospective case series.

OBJECTIVES

To evaluate the feasibility and preliminary efficacy of combining transcutaneous spinal cord stimulation (TSCS) with walking-based physical therapy.

SETTING

Hospital-based outpatient center in Maryland, United States.

METHODS

Ten individuals with chronic (>1 year) motor incomplete spinal cord injury (iSCI) completed 23 sessions of 2-h therapy over 8 weeks. TSCS was delivered for the first 30 min of each session using a clinically available device with adjustable current. To assess feasibility of the intervention, we tracked pain, adverse events, and participant retention. Preliminary efficacy was assessed by evaluating changes in walking speed, endurance, and quality following the intervention with select functional outcome measures (10-m walk test (10MWT), 6-min walk test (6MWT), timed up and go, and walking index for spinal cord injury II).

RESULTS

We found that the combined intervention was feasible in an outpatient clinical setting. Participants tolerated the TSCS well, with no reports of significant adverse events or other issues (e.g., skin irritation or pain that disrupted training). None of the participants elected to discontinue the study. Participants also showed significant improvements in each measure of walking function following the intervention. Changes in walking speed, as measured by the 10MWT (0.56 ± 0.29 m/s to 0.72 ± 0.36 m/s), exceeded the minimal clinically important difference for individuals with iSCI. Changes in walking quality and endurance, as measured by the 6MWT (149.88 ± 99.87 m to 194.53 ± 106.56 m), exceeded the minimal detectable change for individuals with iSCI.

CONCLUSIONS

These results indicate that TSCS is clinically feasible and may be useful as an adjunct to walking-based therapy for adults with iSCI.

Functional Electrical Stimulation Plus Visual Feedback Balance Training for Standing Balance Performance Among Individuals With Incomplete Spinal Cord Injury: A Case Series

Individuals with an incomplete spinal cord injury (iSCI) are highly susceptible to falls during walking or standing. Our objective was to evaluate a therapeutic tool for standing balance that combined functional electrical stimulation, applied bilaterally to the plantarflexors and dorsiflexors, with visual feedback balance training (FES+VFBT). Five adults with iSCI completed 12 FES+VFBT sessions over 4 weeks. During the training sessions, participants completed each of the four balance exercises twice. Visual feedback of the center-of-pressure (COP) location was provided as participants completed the balance exercises and received FES to assist with performance of the exercises. A closed-loop FES system was used in which the COP was continually monitored and the level of electrical current administered was automatically adjusted. Balance abilities were assessed pre- and post- training using clinical balance scales (i.e., Berg Balance Scale, Mini-Balance Evaluation Systems Test, and Activities-specific Balance Confidence Scale) and biomechanical assessments (i.e., postural sway measures and limits of stability test during standing). User acceptability was explored through semi-structured interviews. Improvements were seen for four of the five participants on at least one of the clinical scales following completion of the training intervention. All participants showed greater maximal COP excursion area during the limits of stability test after the training intervention, whereas only one participant demonstrated a reduction in postural sway. Specific components of FES+VFBT, including the ability to safely practice challenging balance exercises, were deemed important by the participants. These results suggest that FES+VFBT has potential as an intervention for standing balance after iSCI.

A Comparison of FES and SCS for Neuroplastic Recovery After SCI: Historical Perspectives and Future Directions

There is increasing evidence that neuroplastic changes can occur even years after spinal cord injury, leading to reduced disability and better health which should reduce the cost of healthcare. In motor-incomplete spinal cord injury, recovery of leg function may occur if repetitive training causes afferent input to the lumbar spinal cord. The afferent input may be due to activity-based therapy without electrical stimulation but we present evidence that it is faster with electrical stimulation. This may be spinal cord stimulation or peripheral nerve stimulation. Recovery is faster if the stimulation is phasic and that the patient is trying to use their legs during the training. All the published studies are small, so all conclusions are provisional, but it appears that patients with more disability (AIS A and B) may need to continue using stimulation and for them, an implanted stimulator is likely to be convenient. Patients with less disability (AIS C and D) may make useful recovery and improve their quality of life from a course of therapy. This might be locomotion therapy but we argue that cycling with electrical stimulation, which uses biofeedback to encourage descending drive, causes rapid recovery and might be used with little supervision at home, making it much less expensive. Such an electrical therapy followed by conventional physiotherapy might be affordable for the many people living with chronic SCI. To put this in perspective, we present some information about what treatments are funded in the UK and the US.

Pavlovian control of intraspinal microstimulation to produce over-ground walking

OBJECTIVE

Neuromodulation technologies are increasingly used for improving function after neural injury. To achieve a symbiotic relationship between device and user, the device must augment remaining function, and independently adapt to day-to-day changes in function. The goal of this study was to develop predictive control strategies to produce over-ground walking in a model of hemisection spinal cord injury (SCI) using intraspinal microstimulation (ISMS).

APPROACH

Eight cats were anaesthetized and placed in a sling over a walkway. The residual function of a hemisection SCI was mimicked by manually moving one hind-limb through the walking cycle. ISMS targeted motor networks in the lumbosacral enlargement to activate muscles in the other, presumably 'paralyzed' limb, using low levels of current (<130 μA). Four people took turns to move the 'intact' limb, generating four different walking styles. Two control strategies, which used ground reaction force and angular velocity information about the manually moved 'intact' limb to control the timing of the transitions of the 'paralyzed' limb through the step cycle, were compared. The first strategy used thresholds on the raw sensor values to initiate transitions. The second strategy used reinforcement learning and Pavlovian control to learn predictions about the sensor values. Thresholds on the predictions were then used to initiate transitions.

MAIN RESULTS

Both control strategies were able to produce alternating, over-ground walking. Transitions based on raw sensor values required manual tuning of thresholds for each person to produce walking, whereas Pavlovian control did not. Learning occurred quickly during walking: predictions of the sensor signals were learned rapidly, initiating correct transitions after ≤4 steps. Pavlovian control was resilient to different walking styles and different cats, and recovered from induced mistakes during walking.

SIGNIFICANCE

This work demonstrates, for the first time, that Pavlovian control can augment remaining function and facilitate personalized walking with minimal tuning requirements.

Changes in bowel function following exoskeletal-assisted walking in persons with spinal cord injury: an observational pilot study

STUDY DESIGN

Prospective, observational study.

OBJECTIVE

To explore the effects of exoskeletal-assisted walking (EAW) on bowel function in persons with spinal cord injury (SCI).

SETTING

Ambulatory research facility located in a tertiary care hospital.

METHODS

Individuals 18-65 years of age, with thoracic vertebrae one (T1) to T11 motor-complete paraplegia of at least 12 months duration were enrolled. Pre- and post-EAW training, participants were asked to report on various aspects of their bowel function as well as on their overall quality of life (QOL) as related to their bowel function.

RESULTS

Ten participants completed 25-63 sessions of EAW over a period of 12-14 weeks, one participant was lost to follow up due to early withdrawal after ten sessions. Due to the small sample size, each participant's results were presented descriptively in a case series format. At least 5/10 participants reported improvements with frequency of bowel evacuations, less time spent on bowel management per bowel day, fewer bowel accidents per month, reduced laxative and/or stool softener use, and improved overall satisfaction with their bowel program post-EAW training. Furthermore, 8/10 reported improved stool consistency and 7/10 reported improved bowel function related QOL. One participant reported worsening of bowel function post-EAW.

CONCLUSION

Between 50 and 80% of the participants studied reported improvements in bowel function and/or management post-EAW training. EAW training appeared to mitigate SCI-related bowel dysfunction and the potential benefits of EAW on bowel function after SCI is worthy or further study.

The effects of FES cycling combined with virtual reality racing biofeedback on voluntary function after incomplete SCI: a pilot study

Background

Functional Electrical Stimulation (FES) cycling can benefit health and may lead to neuroplastic changes following incomplete spinal cord injury (SCI). Our theory is that greater neurological recovery occurs when electrical stimulation of peripheral nerves is combined with voluntary effort. In this pilot study, we investigated the effects of a one-month training programme using a novel device, the iCycle, in which voluntary effort is encouraged by virtual reality biofeedback during FES cycling.

Methods

Eleven participants (C1-T12) with incomplete SCI (5 sub-acute; 6 chronic) were recruited and completed 12-sessions of iCycle training. Function was assessed before and after training using the bilateral International Standards for Neurological Classification of SCI (ISNC-SCI) motor score, Oxford power grading, Modified Ashworth Score, Spinal Cord Independence Measure, the Walking Index for Spinal Cord Injury and 10 m-walk test. Power output (PO) was measured during all training sessions.

Results

Two of the 6 participants with chronic injuries, and 4 of the 5 participants with sub-acute injuries, showed improvements in ISNC-SCI motor score > 8 points. Median (IQR) improvements were 3.5 (6.8) points for participants with a chronic SCI, and 8.0 (6.0) points for those with sub-acute SCI. Improvements were unrelated to other measured variables (age, time since injury, baseline ISNC-SCI motor score, baseline voluntary PO, time spent training and stimulation amplitude; p > 0.05 for all variables). Five out of 11 participants showed moderate improvements in voluntary cycling PO, which did not correlate with changes in ISNC-SCI motor score. Improvement in PO during cycling was positively correlated with baseline voluntary PO (R² = 0.50; p < 0.05), but was unrelated to all other variables (p > 0.05). The iCycle was not suitable for participants who were too weak to generate a detectable voluntary torque or whose effort resulted in a negative torque.

Conclusions

Improved ISNC-SCI motor scores in chronic participants may be attributable to the iCycle training. In sub-acute participants, early spontaneous recovery and changes due to iCycle training could not be distinguished. The iCycle is an innovative progression from existing FES cycling systems, and positive results should be verified in an adequately powered controlled trial.

Trial registration

ClinicalTrials.gov, NCT03834324. Registered 06 February 2019 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03834324. Protocol V03, dated 06.08.2015.

Assessing the ability of the Sacral Autonomic Standards to document bladder and bowel function based upon the Asia Impairment Scale

Study design

Retrospective review of data.

Objective

To determine if there is a relationship between the Asia Impairment Scale (AIS) and the bladder and bowel components of the International Standards to Document Remaining Autonomic Function after SCI (ISAFSCI).

Setting

University-Based Academic Rehabilitation Program.

Methods

Retrospective cross-sectional study assessing International Standards for Neurologic Classification After SCI (ISNCSCI) examination along with bladder and bowel components of the ISAFSCI.

Results

Subjects with AIS A injuries were statistically less likely to have history of bladder control and bowel control per investigator determination and bladder sensation via self-report versus patients categorized with AIS B injuries. Self-reported history of bowel sensation and control of voiding were more likely in subjects with C, D, or E injuries than with B injuries. Bowel and bladder control as determined by investigator and bladder and bowel sensation and control as self-reported were all statistically less likely in persons with AIS A injuries versus CDE.

Conclusions

This retrospective study provides initial data regarding components of the bladder and bowel sections of the sacral ISAFSCI and AIS. Further prospective research is needed to further characterize the relationship between retention of bladder and bowel sensation and function and the AIS. We suggest that incorporation of the sacral components of the ISAFSCI into the ISNCSCI may be beneficial to obtain further information about retention of sacral function with specific patterns of injury.

Activity-Based Training Reverses Spinal Cord Injury-Induced Changes in Kidney Receptor Densities and Membrane Proteins

Complications in upper and lower urinary function arise after spinal cord injury (SCI), which creates a significant impact on quality of life for those affected. One upper urinary complication is SCI-induced polyuria, or the overproduction of urine, of which the underlying mechanisms have yet to be elucidated. Activity-based training (ABT) has been utilized in both animal and clinical settings as a rehabilitative therapy to improve many issues that arise after SCI, including more recently urogenital function. The goal of the current study was to identify potential mechanisms contributing to previously identified improvements in polyuria with ABT, using a male rat moderate-severe spinal contusion model. Although ABT had no significant effect on reversing injury-induced alterations of serum arginine vasopressin and urinary atrial natriuretic peptide levels, there was a dramatic effect upon the receptors of these fluid balance hormones (vasopressin receptor 2 and natriuretic peptide A receptor), as well as kidney aquaporin 2 and sodium channels. ABT changes in densities of key receptors and kidney membrane proteins involved in fluid balance after chronic SCI support the likelihood of multiple mechanisms through which exercise can positively influence urinary tract function after SCI. By understanding the mechanisms, amount, and timing regarding how ABT improves different aspects of urinary function, more targeted training strategies can be developed to optimize the functional gains within the SCI population.

Rehabilitation following spinal cord injury: how animal models can help our understanding of exercise-induced neuroplasticity

Spinal cord injury is a devastating condition that is followed by long and often unsuccessful recovery after trauma. The state of the art approach to manage paralysis and concomitant impairments is rehabilitation, which is the only strategy that has proven to be effective and beneficial for the patients over the last decades. How rehabilitation influences the remodeling of spinal axonal connections in patients is important to understand, in order to better target these changes and define the optimal timing and onset of training. While clinically the answers to these questions remain difficult to obtain, rodent models of rehabilitation like bicycling, treadmill training, swimming, enriched environments or wheel running that mimic clinical rehabilitation can be helpful to reveal the axonal changes underlying motor recovery. This review will focus on the different animal models of spinal cord injury rehabilitation and the underlying changes in neuronal networks that are improved by exercise and rehabilitation.

Clinical Trials in Traumatic Spinal Cord Injury

Traumatic spinal cord injury (SCI) results in impaired neurologic function that for many individuals is permanent and significantly impacts health, function, quality of life, and life expectancy. Many efforts have been taken to develop effective treatments for SCI; nevertheless, proven therapies targeting neurologic regeneration and functional recovery have been limited. Existing therapeutic approaches, including early surgery, strict blood pressure control, and consideration of treatment with steroids, remain debated and largely focus on mitigating secondary injury after the primary trauma has occurred. Today, there is more research being performed in SCI than ever before. Current clinical trials are exploring pharmacologic, cell-based, physiologic, and rehabilitation approaches to reduce secondary injury and also overcome barriers to neurorecovery. In the future, it is likely that tailored treatments combining many of these strategies will offer significant benefits for persons with SCI. This article aims to review key past, current and emerging neurologic and rehabilitation therapeutic approaches for adults with traumatic SCI.

Activity-Based Physical Rehabilitation with Adjuvant Testosterone to Promote Neuromuscular Recovery after Spinal Cord Injury

Neuromuscular impairment and reduced musculoskeletal integrity are hallmarks of spinal cord injury (SCI) that hinder locomotor recovery. These impairments are precipitated by the neurological insult and resulting disuse, which has stimulated interest in activity-based physical rehabilitation therapies (ABTs) that promote neuromuscular plasticity after SCI. However, ABT efficacy declines as SCI severity increases. Additionally, many men with SCI exhibit low testosterone, which may exacerbate neuromusculoskeletal impairment. Incorporating testosterone adjuvant to ABTs may improve musculoskeletal recovery and neuroplasticity because androgens attenuate muscle loss and the slow-to-fast muscle fiber-type transition after SCI, in a manner independent from mechanical strain, and promote motoneuron survival. These neuromusculoskeletal benefits are promising, although testosterone alone produces only limited functional improvement in rodent SCI models. In this review, we discuss the (1) molecular deficits underlying muscle loss after SCI; (2) independent influences of testosterone and locomotor training on neuromuscular function and musculoskeletal integrity post-SCI; (3) hormonal and molecular mechanisms underlying the therapeutic efficacy of these strategies; and (4) evidence supporting a multimodal strategy involving ABT with adjuvant testosterone, as a potential means to promote more comprehensive neuromusculoskeletal recovery than either strategy alone.

Feasibility of robotic exoskeleton ambulation in a C4 person with incomplete spinal cord injury: a case report

INTRODUCTION

To determine whether an individual with C4 incomplete spinal cord injury (SCI) with limited hand functions can effectively operate a powered exoskeleton (Ekso) to improve parameters of physical activity as determined by swing-time, up-time, walk-time, and total number of steps.

CASE PRESENTATION

A 21-year-old male with incomplete chronic (>1 year postinjury) SCI C4, participated in a clinical exoskeleton program to determine the feasibility of standing up and walking with limited hand functions. The participant was invited to attend 3 sessions including fitting, familiarization and gait training separated by one week intervals. Walk-time, up-time and total number of steps were measured during each training session. A complete body composition assessment using dual-energy X-ray absorptiometry (DXA) of the spine, knees and hips was conducted before training.Using a platform walker and cuffing both hands, the participant managed to stand up and ambulate successfully using exoskeleton. Over the course of 2 weeks, maximum walk-time increased from 7 to 17 min and number of steps increased from 83 to 589 steps. The total up-time increased from 19 to 31 min.

DISCUSSION

Exoskeleton training may be a safe and feasible approach for persons with higher levels of SCI after effectively providing a supportive assistive device for weight shifting. The current case study demonstrates the use of a powered exoskeleton for an individual with high level tetraplegia (C4 and above) and limited hand functions.