Effects of body weight-supported treadmill training on heart rate variability and blood pressure variability in individuals with spinal cord injury

Effect of anti-gravity treadmill (Alter G) training on gait characteristics and postural stability in adult with healed burns: A single blinded randomized controlled trial

BACKGROUND

Burns constitute one of the foremost contributors to premature mortality and morbidity, and the recovery process from burn injuries is characterized by its intricate and protracted nature.

OBJECTIVE

The principal aim of this study was to assess the influence of an anti-gravity treadmill (Alter G) training program on both gait characteristics and postural stability indices (PSI) in adult individuals who have recovered from burns.

DESIGN

This study followed a single-blind, randomized, controlled design.

METHODS

A total of 45 adults, aged 18-35 years, with healed lower extremity burns that were circumferential and encompassed 35-50% of their total body surface area (TBSA) were randomly allocated to either the anti-gravity treadmill (Alter G) Training group (n = 22) or the traditional physical therapy program (TPTP) group (n=23). The TPTP group received conventional physical therapy, while the anti-gravity treadmill (Alter G) training group engaged in anti-gravity treadmill exercises alongside the traditional physical therapy program. The primary outcome measures, evaluated at both baseline and the conclusion of the 12-week intervention, included gait characteristics assessed using the GAITRite system and PSI measured by the Biodex Balance System (BBS).

RESULTS

The anti-gravity treadmill (Alter G) training group exhibited significantly greater enhancements than the TPTP group in terms of mean values and percentage changes in gait characteristics and PSI. Specifically, the percentage changes for the Alter G group were as follows: stride length (20.57%), step time (22.58%), step length (20.47%), velocity (15.67%), cadence (23.28%), and double support time (29.03%). In contrast, the TPTP group's percentage changes were: 6.73%, 8.19%, 7.65%, 7.75%, 8.89%, and 9.37%, respectively. Concerning PSI, the Alter G group exhibited percentage changes of 55.17% for the medio-lateral stability index (MLI), 48.21% for antero-posterior stability index (API), and 48.48% for the overall stability index (OSI). The TPTP group's corresponding percentage changes were 20%, 14.03%, and 16.41%.

CONCLUSIONS

The amalgamation of anti-gravity treadmill training with the traditional physical therapy program yields greater efficacy than TPTP in isolation. Consequently, the findings underscore the efficiency of anti-gravity treadmill (Alter G) Training as a valuable tool for rehabilitating patients with burn injuries.

Effects of percutaneously-implanted epidural stimulation on cardiovascular autonomic function and spasticity after complete spinal cord injury: A case report

Importance

There is a revived interest to explore spinal cord epidural stimulation (SCES) to improve physical function after spinal cord injury (SCI). This case report highlights the potential of eliciting multiple functional improvements with a single SCES configuration, a strategy which could improve clinical translation.

Objective

To determine whether SCES intended to facilitate walking also acutely yields benefits in cardiovascular autonomic regulation and spasticity.

Design

Case report from data collected at two timepoints 15 weeks apart from March to June 2022 as part of a larger clinical trial.

Setting

Research lab at Hunter Holmes McGuire VA Medical Center.

Participant

27-year-old male, 7 years post a C8 motor complete spinal cord injury.

Intervention

A SCES configuration intended to enhance exoskeleton-assisted walking training applied for autonomic and spasticity management.

Main outcomes and measures

The primary outcome was cardiovascular autonomic response to a 45-degree head-up-tilt test. Systolic blood pressure (SBP), heart rate (HR), and absolute power of the low-frequency (LF) and high-frequency (HF) components of a heart-rate variability analysis were collected in supine and tilt with and without the presence of SCES. Right knee flexor and knee extensor spasticity was assessed via isokinetic dynamometry with and without SCES.

Results

At both assessments with SCES off, transitioning from supine to tilt decreased SBP (assessment one: 101.8 to 70 mmHg; assessment two: 98.9 to 66.4 mmHg). At assessment one, SCES on in supine (3 mA) increased SBP (average 117 mmHg); in tilt, 5 mA stabilized SBP near baseline values (average 111.5 mmHg). At assessment two, SCES on in supine (3 mA) increased SBP (average 140 mmHg in minute one); decreasing amplitude to 2 mA decreased SBP (average 119 mmHg in minute five). In tilt, 3 mA stabilized SBP near baseline values (average 93.2 mmHg). Torque-time integrals at the right knee were reduced at all angular velocities for knee flexors (range: -1.9 to -7.8%) and knee extensors (range: -1 to -11.4%).

Conclusions and relevance

These results demonstrate that SCES intended to facilitate walking may also enhance cardiovascular autonomic control and attenuate spasticity. Using one configuration to enhance multiple functions after SCI may accelerate clinical translation.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/, identifier NCT04782947.

Human movement in simulated hypogravity-Bridging the gap between space research and terrestrial rehabilitation

Human movement is optimized to Earth's gravity and based on highly complex interactions between sensory and neuro-muscular systems. Yet, humans are able to adapt-at least partially-to extreme environments upon and beyond Earth's surface. With upcoming Lunar Gateway and Artemis missions, it is crucial to increase our understanding of the impact of hypogravity-i.e., reduced vertical loading-on physiological and sensory-motor performances to improve countermeasure programs, and define crewmember's readiness to perform mission critical tasks. Several methodologies designed to reduce vertical loading are used to simulate hypogravity on Earth, including body weight support (BWS) devices. Countering gravity and offloading the human body is also used in various rehabilitation scenarios to improve motor recovery in neurological and orthopedic impairments. Thus, BWS-devices have the potential of advancing theory and practice of both space exploration and terrestrial rehabilitation by improving our understanding of physiological and sensory-motor adaptations to reduced vertical loading and sensory input. However, lack of standardization of BWS-related research protocols and reporting hinders the exchange of key findings and new advancements in both areas. The aim of this introduction paper is to review the role of BWS in understanding human movement in simulated hypogravity and the use of BWS in terrestrial rehabilitation, and to identify relevant research areas contributing to the optimization of human spaceflight and terrestrial rehabilitation. One of the main aims of this research topic is to facilitate standardization of hypogravity-related research protocols and outcome reporting, aimed at optimizing knowledge transfer between space research and BWS-related rehabilitation sciences.

Evaluation of Cardiovascular Autonomic Function during Inpatient Rehabilitation following Traumatic Spinal Cord Injury

Assessment of the degree of impaired autonomic nervous system (ANS) function is not part of routine clinical practice during inpatient rehabilitation following traumatic spinal cord injury (SCI). The goal of this investigation was to determine the utility of the International Standards for Neurologic Classification of SCI (ISNCSCI) and the recently revised International Standards to document remaining Autonomic Function after SCI (ISAFSCI) in documenting cardiovascular ANS impairment during inpatient rehabilitation following traumatic SCI. Beat-to-beat recording of supine heart rate (HR) and blood pressure (BP) were collected at the bedside for estimation of total cardiovascular ISAFSCI score, cardio-vagal modulation (i.e., high frequency HR variability [HFHRV]) and sympathetic vasomotor regulation (i.e., Mayer wave component of systolic BP [SBPmayer]). A total of 41 participants completed baseline testing, which was conducted 11 ± 5 days from the admission ISNCSCI examination. There were no differences in supine HR or BP based on the ISNCSCI or ISAFSCI assessments. The HFHRV was generally lower with more distal lesions (r2 = 0.15; p = 0.01), and SBPmayer was significantly lower in those with American Spinal Injury Association Impairment Scale (AIS) A compared with AIS B, C, D (Cohen's d = -1.4; p < 0.001). There were no significant differences in HFHRV or SBPmayer in patients with or without ISAFSCI evidence of cardiovascular ANS impairment. These preliminary data suggest that neither the ISNCSCI nor the ISAFSCI are sensitive to changes in ANS cardiovascular function following traumatic SCI. Bedside assessment of HR and BP variabilities may provide insight, but are not readily available in the clinical setting. Further research is required to evaluate methods that accurately assess the degree of ANS impairment following traumatic SCI.

Effects of walking training on risk markers of cardiovascular disease in individuals with chronic spinal cord injury

OBJECTIVE

To investigate the effects of an 8-week walking training program on glycemic control, lipid profile, and inflammatory markers in individuals with chronic spinal cord injury (SCI).

DESIGN

A pilot, single-group, pretest-posttest study.

SETTING

A neuromuscular research laboratory.

PARTICIPANTS

Eleven participants with chronic SCI.

INTERVENTION

An 8-week walking training program using a treadmill, a body weight-supported system, and an assistive gait training device.

OUTCOME MEASURES

Levels of glycated hemoglobin (HbA_1c), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), and interleukin-6 were assessed before and after the walking training.

RESULTS

Following the walking training, there was a statistically significant decrease in HbA_1c level (P<0.01) of uncertain clinical significance. The lipid profile improved after training, as shown by a statistically and clinically significant increase in HDL-C level (P<0.01) and a statistically significant decrease in LDL-C level (P<0.1) of no clinical significance. The ratio of LDL-C to HDL-C was significantly reduced (P<0.01). In regard to inflammatory markers, concentrations of IL-6 showed a significant reduction after training (P=0.05) of unknown clinical significance, while those of CRP trended to decrease (P=0.13).

CONCLUSION

The findings of this pilot study suggest that an 8-week walking training program may produce favorable changes in risk markers of cardiovascular disease in individuals with chronic SCI as shown by clinically meaningful improvements in HDL-C, and small changes in the right direction, but uncertain clinical significance, in HbA1c, LDL-C and IL-6. A randomized controlled trial is needed to compare the effects of walking training on these outcome measures with those of other exercise modalities suitable for this population, and to see if more prolonged exercise exposure leads to favorable parameters of significant size to justify the exercise modality.

Respiratory Training and Plasticity After Cervical Spinal Cord Injury

While spinal cord injuries (SCIs) result in a vast array of functional deficits, many of which are life threatening, the majority of SCIs are anatomically incomplete. Spared neural pathways contribute to functional and anatomical neuroplasticity that can occur spontaneously, or can be harnessed using rehabilitative, electrophysiological, or pharmacological strategies. With a focus on respiratory networks that are affected by cervical level SCI, the present review summarizes how non-invasive respiratory treatments can be used to harness this neuroplastic potential and enhance long-term recovery. Specific attention is given to "respiratory training" strategies currently used clinically (e.g., strength training) and those being developed through pre-clinical and early clinical testing [e.g., intermittent chemical stimulation via altering inhaled oxygen (hypoxia) or carbon dioxide stimulation]. Consideration is also given to the effect of training on non-respiratory (e.g., locomotor) networks. This review highlights advances in this area of pre-clinical and translational research, with insight into future directions for enhancing plasticity and improving functional outcomes after SCI.

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

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

Intensive Locomotor Training Provides Sustained Alleviation of Chronic Spinal Cord Injury-Associated Neuropathic Pain: A Two-Year Pre-Clinical Study

Neuropathic pain often accompanies the functional deficits associated with spinal cord injury (SCI) and further reduces a patient's quality of life. Clinical and pre-clinical research is beginning to highlight the beneficial role that rehabilitative therapies such as locomotor training can have not only on functional recovery but also on chronic pain management. Our group has previously developed an intensive locomotor training (ILT) treadmill protocol on rats that reduced SCI neuropathic pain symptoms for at least 3 months. We have extended these findings in the current study to evaluate the ability of regular ILT regimen over a 2 year period post-SCI to maintain neuropathic pain reduction. To assess this, the rat clip compression SCI model (T7/8) was used and treadmill training was initiated starting 4 weeks after SCI and continuing through the duration of the study. Results showed continued suppression of SCI neuropathic pain responses (reduced mechanical, heat, and cold hypersensitivity throughout the entire time course of the study). In contrast, non-exercised rats showed consistent and sustained neuropathic pain responses during this period. In addition, prolonged survival and improved locomotor outcomes were observed in rats undergoing ILT as the study longevity progressed. Potential contributory mechanisms underlying beneficial effects of ILT include reduced inflammation and restoration of anti-nociceptive inhibitory processes as indicated by neurochemical assays in spinal tissue of remaining rats at 2 years post-SCI. The benefits of chronic ILT suggest that long-term physical exercise therapy can produce powerful and prolonged management of neuropathic pain, partly through sustained reduction of spinal pathological processes.

Cardiac, Autonomic, and Cardiometabolic Impact of Exercise Training in Spinal Cord Injury: A QUALITATIVE REVIEW

INTRODUCTION

Direct and indirect effects of spinal cord injury lead to important cardiovascular (CV) complications that are further increased by years of injury and the process of "accelerated aging." The present review examines the current evidence in the literature for the potential cardioprotective effect of exercise training in spinal cord injury.

REVIEW METHODS

PubMed and Web of Science databases were screened for original studies investigating the effect of exercise-based interventions on aerobic capacity, cardiac structure/function, autonomic function, CV function, and/or cardiometabolic markers. We compared the effects in individuals <40 yr with time since injury <10 yr with those in older individuals (≥40 yr) with longer time since injury (≥10 yr), reasoning that the two can be considered individuals with low versus high CV risk factors.

SUMMARY

Studies showed similar exercise effects in both groups (n = 31 in low CV risk factors vs n = 15 in high CV risk factors). The evidence does not support any effect of exercise training on autonomic function but does support an increased peripheral blood flow, improved left ventricular mass, higher peak cardiac output, greater lean body mass, better antioxidant capacity, and improved endothelial function. In addition, some evidence suggests that it can result in lower blood lipids, systemic inflammation (interleukin-6, tumor necrosis factor α, and C-reactive protein), and arterial stiffness. Training intensity, volume, and frequency were key factors determining CV gains. Future studies with larger sample sizes, well-matched groups of subjects, and randomized controlled designs will be needed to determine whether high-intensity hybrid forms of training result in greater CV gains.

Effect of Exercise on Cardiovascular Function Following Spinal Cord Injury: A REVIEW

Spinal cord injury (SCI) is associated with a reduced level of physical activity, deterioration of patient body composition, metabolic profile, quality of life, and psychological functioning. As a result, risk of cardiovascular disease (CVD) increases and CVD-related death occurs at an earlier age than in individuals without SCI. Regular participation in exercise has been shown to exert beneficial effects also in patients with SCI. In this review, we analyze and discuss the effects of regular exercise training in SCI on cardiovascular function, autonomic function of the cardiovascular system, arterial stiffness, metabolism, inflammation, and gene expression.

The Effect of Exercise on the Older Adult's Blood Pressure Suffering Hypertension: Systematic Review and Meta-Analysis on Clinical Trial Studies

Background

Senescence refers to spontaneous and progressive irreversible degenerative changes in which both the physical and psychological power diminish significantly. Hypertension is the most common cardiovascular disease in the elderly. Several studies have been conducted regarding the effect of exercise on reducing the blood pressure of the elderly, which have found contradictory results. One of the uses of meta-analysis study is responding to these assumptions and resolving the discrepancies. Accordingly, the aim of the present study is to determine the impact of exercise on the blood pressure of older adults.

Method

In this research, in order to find electronic published papers from 1992 to 2019, the papers published in both domestic and foreign databases including SID, MagIran, IranMedex, IranDox, Gogole Scholar, Cohrane, Embase, Science Direct, Scopus, PubMed, and Web of Science (ISI) were used. Heterogeneity index between the studies was determined based on Cochran test Q(c) and I². Considering existence of heterogeneity, random effects model was employed to estimate the standardized subtraction of the mean exercise test score for reduction of blood pressure in the older adults across the intervention group before and after the test.

Results

In this meta-analysis and systematic review, eventually 69 papers met the inclusion criteria. The total number of participants was 2272 in the pre- and postintervention groups when examining the systolic changes and 2252 subjects in the pre- and postintervention groups when inspecting the diastolic changes. The standardized mean difference in examining the systolic changes before the intervention was 137.1 ± 8.09 and 132.98 ± 0.96 after the intervention; when exploring the diastolic changes, the pre- and postintervention values were 80.3 ± 0.85 and 76.0 ± 6.56, respectively, where these differences were statistically significant (P < 0.01).

Conclusion

The results of this study indicated that exercise leads to significant reduction in both systolic and diastolic blood pressure. Accordingly, regular exercise can be part of the treatment plan for hypertensive elderly.

Effects of Robot-Assisted Gait Training in Patients with Burn Injury on Lower Extremity: A Single-Blind, Randomized Controlled Trial

This study investigated the effects of robot-assisted gait training (RAGT) on gait function in burn patients. Briefly, 40 burn patients were randomly divided into an RAGT group or a conventional training (CON) group. SUBAR^® (Cretem, Korea) is a wearable robot with a footplate that simulates normal gait cycles. The RAGT group underwent 30 min of robot-assisted training using SUBAR^® with 30 min of conventional physiotherapy once a day, 5 days a week for 12 weeks. Patients in the CON group received 30 min of overground gait training and range-of-motion (ROM) exercises twice a day for 5 days a week for 12 weeks. The RAGT group and the CON group underwent 60 min of training per day. The intervention frequency and duration did not differ between the RAGT group and the CON group. The main outcomes were functional ambulatory category (FAC); 6-min walking test (6MWT); visual analogue scale (VAS) during gait movement; ROM; and isometric forces of bilateral hip, knee, and ankle muscles before and after 12 weeks of training. The results of the VAS, FAC, and 6MWT (8.06 ± 0.66, 1.76 ± 0.56, and 204.41 ± 85.60) before training in the RAGT group improved significantly (4.41 ± 1.18, 4.18 ± 0.39, and 298.53 ± 47.75) after training (p < 0.001, p < 0.001, and p < 0.001). The results of the VAS, FAC, and 6MWT (8.00 ± 1.21, 1.75 ± 0.58, and 220.94 ± 116.88) before training in the CON group improved significantly (5.00 ± 1.03, 3.81 ± 1.05, and 272.19 ± 110.14) after training (p < 0.001, p < 0.001, and p = 0.05). There were differences in the improvement of results of the VAS, FAC, and 6MWT between groups after training, but they were not statistically significant (p = 0.23, p = 0.14, and p = 0.05). The isometric strengths of the right hip extensor (p = 0.02), bilateral knee flexor (p = 0.04 in the right, and p = 0.001 in the left), bilateral knee extensor (p = 0.003 in the right, and p = 0.002 in the left), bilateral ankle dorsiflexor (p = 0.04 in the right, and p = 0.02 in the left), and bilateral ankle plantarflexor (p = 0.001 in the right, and p = 0.008 in the left) after training were significantly improved compared with those before training in the RAGT group. The ROMs of the right knee extension (p = 0.03) and bilateral ankle plantarflexion (p = 0.008 in the right, and p = 0.03 in the left) were significantly improved compared with measurements before training in the RAGT. There were no significant differences of the isometric strengths and ROMs of the bilateral hip, knee, and ankle muscles after training in the CON group. There were significant improvements in the isometric strengths of the left knee flexor (p = 0.01), left ankle dorsiflexor (p = 0.01), and left ankle plantarflexor (p = 0.003) between the two groups. The results suggested that RAGT is effective to facilitate early recovery of muscles strength after a burn injury. This is the first study to evaluate the effectiveness of RAGT in patients with burns compared with those receiving conventional training. The absence of complications in burn patients provides an opportunity to enlarge the application area of RAGT.

Effect of Body Weight-Supported Treadmill Training on Cardiovascular and Pulmonary Function in People With Spinal Cord Injury: A Systematic Review

Objective: To assess the current evidence with regard to the effects of body weight-supported treadmill training (BWSTT) on cardiovascular and pulmonary function in people with spinal cord injury (SCI) with a focus on outcomes of heart rate (HR), blood pressure (BP), and respiratory parameters. Methods: A systematic literature search was conducted through MEDLINE/PubMed, the Cumulative Index to Nursing and Allied Health Literature, and Physiotherapy Evidence Database. Clinical trials involving adults with SCI and focusing on the effects of BWSTT on HR, BP, and respiratory measurements were included. The quality of included studies was assessed using the Downs and Black scale. The level of evidence of each study was identified using the Spinal Cord Injury Rehabilitation Evidence system. Results: Nine studies that met inclusion criteria were evaluated and included in this review. Overall, the quality index of all included studies was low. All studies scored less than 21 out of 28 on the Downs and Black scale. The level of evidence varied from level 2 to level 4. Level 4 evidence supports the use of BWSTT to decrease resting and exercise HR and improve heart rate variability. The use of BWSTT to improve respiratory parameters after SCI is supported by one study with level 2 evidence. The evidence that supports the use of BWSTT to improve resting BP is inconclusive. Conclusion: There has been low to moderate evidence to support the use of BWSTT in individuals with SCI to improve cardiovascular and pulmonary health. Future randomized controlled trials are needed to investigate the effect of BWSTT on cardiovascular and pulmonary function in people with SCI and compare BWSTT to other physical rehabilitation interventions.

Is Technology for Orthostatic Hypotension Ready for Primetime?

Spinal cord injury (SCI) often results in the devastating loss of motor, sensory, and autonomic function. After SCI, the interruption of descending sympathoexcitatory pathways disrupts supraspinal control of blood pressure (BP). A common clinical consequence of cardiovascular dysfunction after SCI is orthostatic hypotension (OH), a debilitating condition characterized by rapid profound decreases in BP when assuming an upright posture. OH can result in a diverse array of insidious and pernicious health consequences. Acute effects of OH include decreased cardiac filling, cerebral hypoperfusion, and associated presyncopal symptoms such as lightheadedness and dizziness. Over the long term, repetitive exposure to OH is associated with a drastically increased prevalence of heart attack and stroke, which are leading causes of death in those with SCI. Current recommendations for managing BP after SCI primarily include pharmacologic interventions with prolonged time to effect. Because most episodes of OH occur in less than 3 minutes, this delay in action often renders most pharmacologic interventions ineffective. New innovative technologies such as epidural and transcutaneous spinal cord stimulation are being explored to solve this problem. It might be possible to electrically stimulate sympathetic circuitry caudal to the injury and elicit rapid modulation of BP to manage OH. This review describes autonomic control of the cardiovascular system before injury, resulting cardiovascular consequences after SCI such as OH, and the clinical assessment tools for evaluating autonomic dysfunction after SCI. In addition, current approaches for clinically managing OH are outlined, and new promising interventions are described for managing this condition.

Rehabilitative Training in Animal Models of Spinal Cord Injury

Rehabilitative motor training is currently one of the most widely used approaches to promote moderate recovery following injuries of the central nervous system. Such training is generally applied in the clinical setting, whereas it is not standard in preclinical research. This is a concern as it is becoming increasingly apparent that neuroplasticity enhancing treatments require training or some form of activity as a co-therapy to promote functional recovery. Despite the importance of training and the many open questions regarding its mechanistic consequences, its use in preclinical animal models is rather limited. Here we review approaches, findings and challenges when training is applied in animal models of spinal cord injury, and we suggest recommendations to facilitate the integration of training using an appropriate study design, into pre-clinical studies.

Activity-Based Training Alters Penile Reflex Responses in a Rat Model of Spinal Cord Injury

INTRODUCTION

Multisystem functional gains have been reported in males with spinal cord injury (SCI) after undergoing activity-based training (ABT), including increases in scoring of sexual function and reports of improved erectile function.

AIM

This study aims to examine the effect of daily 60-minute locomotor training and exercise in general on sexual function in a rat SCI contusion model.

METHODS

Male Wistar rats received a T9 contusion SCI. Animals were randomized into 4 groups: a quadrupedal stepping group (SCI + QT), a forelimb-only exercise group (SCI + FT), a non-trained harnessed group (SCI + NT), and a home cage non-trained group (SCI + HC). The 2 non-trained groups were combined (SCI) post hoc. Daily training sessions were 60 minutes in duration for 8 weeks. Urine samples were collected during bi-weekly 24-hour metabolic cage behavioral testing. Latency, numbers of penile dorsiflexion, and glans cupping were recorded during bi-weekly penile dorsiflexion reflex (PDFR) testing. Terminal electromyography (EMG) recordings of the bulbospongiosus muscle (BSM) were recorded in response to stimulation of the dorsal nerve of the penis (DNP).

OUTCOMES

ABT after SCI had a significant effect on PDFR, as well as BSM EMG latency and burst duration.

RESULTS

SCI causes a significant decrease in the latency to onset of PDFR. After 8 weeks of ABT, SCI + QT animals had a significantly increased latency relative to the post-SCI baseline. BSM EMG response to DNP stimulation had a significantly decreased latency and increase in average and maximum amplitude in SCI + QT animals. SCI animals had a significantly longer burst duration than trained animals. Time between PDFR events, penile dorsiflexion, glans cupping, and urine testosterone were not affected by ABT.

CLINICAL IMPLICATIONS

ABT has a positive influence on sexual function and provides a potential therapy to enhance the efficacy of current sexual dysfunction therapies in the male SCI population.

STRENGTHS AND LIMITATIONS

Several significant small improvements in sexual function were found in a clinically relevant rat model of SCI using a readily available rehabilitative therapy. The limited findings could reflect insensitivity of the PDFR as a measure of erectile function.

CONCLUSIONS

These results indicate that task-specific stepping and/or loading provide sensory input to the spinal cord impacting the neural circuitry responsible for sexual function. Steadman CJ, Hoey RF, Montgomery LR, et al. Activity-Based Training Alters Penile Reflex Responses in a Rat Model of Spinal Cord Injury. J Sex Med 2019; 16:1143-1154.

Neurohumoral and ambulatory haemodynamic adaptations following isometric exercise training in unmedicated hypertensive patients

OBJECTIVE

Hypertension remains the leading modifiable risk factor for cardiovascular disease. Isometric exercise training (IET) has been shown to be a useful nonpharmacological intervention for reducing resting blood pressure (BP). This study aimed to measure alterations in office BP, ambulatory BP, cardiac autonomic modulation and inflammatory and vascular biomarkers following a programme of IET in unmedicated hypertensive patients.

METHODS

Twenty-four unmedicated stage 1 hypertensive patients (age 43.8 ± 7.3 years; height, 178.1 ± 7 cm; weight 89.7 ± 12.8 kg) were randomly assigned in a cross-over study design, to 4-weeks of home-based IET and control period, separated by a 3-week washout period. Office and ambulatory BP, cardiac autonomic modulation, and inflammatory and vascular biomarkers were recorded pre and post-IET and control periods.

RESULTS

Clinic and 24-h ambulatory BP significantly reduced following IET by 12.4/6.2 and 11.8/5.6 mmHg in SBP/DBP, respectively (P < 0.001 for both), compared with the control. The BP adaptations were associated with a significant (P = 0.018) reduction in the average real variability of 24-h ambulatory BP following IET, compared with control. Cardiac autonomic modulation improved by 11% (P < 0.001), baroreceptor reflex sensitivity improved by 47% (P < 0.001), and IL-6 and asymmetric dimethylarginine reduced by 10% (P = 0.022) and 19% (P = 0.023), respectively, which differed significantly to the control period.

CONCLUSION

This is the first evidence of durable BP reduction and wider cardiovascular disease risk benefits of IET in a relevant patient population. Our findings support the role of IET as a safe and viable therapeutic and preventive intervention in the treatment of hypertension.

Exercise-Induced Alterations in Sympathetic-Somatomotor Coupling in Incomplete Spinal Cord Injury

The aim of this study was to understand how high- and low-intensity locomotor training (LT) affects sympathetic-somatomotor (SS) coupling in people with incomplete spinal cord injury (SCI). Proper coupling between sympathetic and somatomotor systems allows controlled regulation of cardiovascular responses to exercise. In people with SCI, altered connectivity between descending pathways and spinal segments impairs sympathetic and somatomotor coordination, which may have deleterious effects during exercise and limit rehabilitation outcomes. We postulated that high-intensity LT, which repeatedly engages SS systems, would alter SS coupling. Thirteen individuals (50 ± 7.2 years) with motor incomplete spinal cord injuries (American Spinal Injury Association Impairment Scale C or D; injury level >T6) participated in a locomotor treadmill training program. Patients were randomized into either a high-intensity (high-LT; 70-85% of maximum predicted heart rate; n = 6) group or a low-intensity (low-LT; 50-65% of maximum predicted heart rate; n = 7) group and completed up to 20 LT training sessions over 4-6 weeks, 3-5 days/week. Before and after taining, we tested SS coupling by eliciting reflexive sympathetic activity through a cold stimulation, noxious stimulation, and a mental math task while we measured tendon reflexes, blood pressure, and heart rate. Participants who completed high- versus low-LT exhibited significant decreases in reflex torques during triggered sympathetic activity (cold: -83 vs. 13%, p < 0.01; pain: -65 vs. 54%, p < 0.05; mental math: -43 vs. 41%; p < 0.05). Mean arterial pressure responses to sympathetic stimuli were slightly higher following high- versus low-LT (cold: 30 vs. -1.5%; pain: 6 vs. -12%; mental math: 5 vs. 7%), although differences were not statistically significant. These results suggest that high-LT may be advantageous to low-LT to improve SS coupling in people with incomplete SCI.

Effects of exercise interventions on cardiovascular health in individuals with chronic, motor complete spinal cord injury: protocol for a randomised controlled trial [Cardiovascular Health/Outcomes: Improvements Created by Exercise and education in SCI (CHOICES) Study]

INTRODUCTION

Recent studies demonstrate that cardiovascular diseases and associated complications are the leading cause of morbidity and mortality in individuals with spinal cord injury (SCI). Abnormal arterial stiffness, defined by a carotid-to-femoral pulse wave velocity (cfPWV) ≥10 m/s, is a recognised risk factor for heart disease in individuals with SCI. There is a paucity of studies assessing the efficacy of conventional training modalities on arterial stiffness and other cardiovascular outcomes in this population. Therefore, this study aims to compare the efficacy of arm cycle ergometry training (ACET) and body weight-supported treadmill training (BWSTT) on reducing arterial stiffness in individuals with chronic motor complete, high-level (above the sixth thoracic segment) SCI.

METHODS AND ANALYSIS

This is a multicentre, randomised, controlled, clinical trial. Eligible participants will be randomly assigned (1:1) into either ACET or BWSTT groups. Sixty participants with chronic (>1 year) SCI will be recruited from three sites in Canada (Vancouver, Toronto and Hamilton). Participants in each group will exercise three times per week up to 30 min and 60 min for ACET and BWSTT, respectively, over the period of 6 months. The primary outcome measure will be change in arterial stiffness (cfPWV) from baseline. Secondary outcome measures will include comprehensive assessments of: (1) cardiovascular parameters, (2) autonomic function, (3) body composition, (4) blood haematological and metabolic profiles, (5) cardiorespiratory fitness and (6) quality of life (QOL) and physical activity outcomes. Outcome measures will be assessed at baseline, 3 months, 6 months and 12 months (only QOL and physical activity outcomes). Statistical analyses will apply linear-mixed modelling to determine the training (time), group (ACET vs BWSTT) and interaction (time × group) effects on all outcomes.

ETHICS AND DISSEMINATION

Ethical approval was obtained from all three participating sites. Primary and secondary outcome data will be submitted for publication in peer-reviewed journals and widely disseminated.

TRIAL REGISTRATION NUMBER

NCT01718977; Pre-results.

TRIAL STATUS

Recruitment for this study began on January 2013 and the first participant was randomized on April 2013. Recruitment stopped on October 2018.

An examination of diurnal variations in neuropathic pain and affect, on exercise and non-exercise days, in adults with spinal cord injury

STUDY DESIGN

Case series.

OBJECTIVES

The temporal relationships between exercise, neuropathic pain and affect are not well understood. The purpose of this study was to utilize ecological momentary assessment to measure intra-individual diurnal variations in neuropathic pain and affect on exercise and non-exercise days. This study aimed to provide a deeper understanding of how neuropathic pain and affect change from pre- to post-exercise, and over time.

SETTING

Community.

METHODS

Six physically active men with SCI participated in a 6-day protocol (M age = 39.33 ± 8.24; 83.3% tetraplegics; years post injury = 6-17 years). Using their Smartphones, participants completed the Feeling Scale, Felt Arousal Scale, and Neuropathic Pain Scale in response to six daily prompts, and before and after exercise. Paired samples t-tests were conducted on changes in neuropathic pain and affect from pre to post-exercise. Bivariate Pearson's correlational analyses were computed between time of day, neuropathic pain and affect.

RESULTS

Participants experienced a significant decrease in neuropathic pain (t(5) = 3.93; p = 0.01) following completion of at least one bout of exercise. A large, but non-significant increase (Hgav = 0.76) in Feeling Scale scores occurred following one bout of exercise. Time of day, neuropathic pain and affect were significantly correlated for two participants.

CONCLUSIONS

Overall, results suggest exercise can reduce neuropathic pain, and may also increase feelings of pleasure. Given the inconsistent pattern of results across participants, further research is needed to look at both individual characteristics, and characteristics of exercise that may moderate changes in neuropathic pain and affect for adults with SCI.

Cardiac autonomic and left ventricular mechanics following high intensity interval training: a randomized crossover controlled study

Physical inactivity and sedentary behavior is associated with increased cardiovascular disease risk. Short duration high-intensity interval training (HIIT) has been shown to improve important health parameters. The aim of the present study was to assess the combined adaptations of the cardiac autonomic nervous system and myocardial functional and mechanical parameters to HIIT. Forty physically inactive and highly sedentary men completed two weeks of HIIT and control period. The HIIT protocol consisted of 3 × 30-s maximal cycle ergometer sprints against a resistance of 7.5% body weight, interspersed with 2 min of active recovery. Total power spectral density (PSD) and associated low-frequency (LF) and high-frequency (HF) power spectral components of heart rate variability were recorded. Conventional and speckle tracking echocardiography recorded left ventricular (LV) structural, functional, and mechanical parameters. HIIT produced a significant increase in total log-transformed (ln) PSD and ln HF and a significant decrease in LF/HF ratio (all P < 0.05) compared with the control period. HIIT produced significant improvements in LV diastolic function, including lateral E', estimated filling pressure (E/E' ratio), E deceleration time, and isovolumetric relaxation time ( P < 0.05 for all). Fractional shortening was the only conventional marker of LV systolic function to significantly improve ( P < 0.05). In this setting, there were significant improvements in global peak systolic strain rate, early and late diastolic strain rate, and early to late diastolic strain rate ratio, as well as apical rotation, apical systolic and diastolic rotation velocity, apical radial and circumferential strain and strain rate, LV torsion, and LV systolic and diastolic torsion velocity (all P < 0.05). A short-term program of HIIT was associated with a significant increase in cardiac autonomic modulation, demonstrated by a residual increase in cardiac vagal activity as well as significantly improved cardiac function and mechanics. This study demonstrates that HIIT may be an important stimulus to reduce the health implications associated with physical inactivity and sedentary behavior. NEW & NOTEWORTHY This is the first study to measure the combined adaptations of the cardiac autonomic nervous system and myocardial function and mechanics following high-intensity interval training (HIIT). This study demonstrates that a 2-wk HIIT intervention provides significant improvements in cardiac autonomic modulation and myocardial function and mechanics in a large cohort of young physically inactive and highly sedentary individuals. HIIT may be a powerful stimulus to reduce the health implications associated with physical inactivity and sedentary behavior.

Body mass index mortality paradox in chronic kidney disease patients with suspected cardiac chest pain

Background: Chronic kidney disease (CKD) is a silent clinical condition associated with adverse comorbidity and high cardiovascular disease (CVD) risk. An inverse relationship with body mass index (BMI) and mortality has been demonstrated in hemodialysis patients. However, it is unclear if this risk-factor paradox is evident in non-dialysis CKD patients. The aims of this study were to explore the relationship between, nutritional status, markers of inflammation, autonomic and cardiac function with BMI. Longitudinal follow-up explored the relationship between BMI and all-cause mortality. Methods: 211-consecutive CKD patients referred for dobutamine stress echocardiography to detect or exclude myocardial ischemia were recruited. BMI, albumin, C-reactive protein (CRP) and haemoglobin (Hb) were recorded as markers of nutritional and inflammatory status. Left ventricular ejection fraction (LVEF) and heart rate variability (HRV) as an indicator of cardiac function was recorded. All subjects were followed prospectively until November 2014 and study end-point was all-cause mortality. Results: BMI was inversely associated with CKD status. After covariate adjustment, this association remained. During a mean follow-up period of 3.3±0.9 years there were 35 deaths (17%). BMI was inversely associated with all-cause mortality (HR 0.81, 95% CI 0.71-0.9). Other important independent predictors of mortality were heart rate variability (HR 0.98, 95% CI 0.97-0.99), myocardial ischemia (HR 1.37, 95% CI 1.17-1.81), and albumin (HR 0.86, 95% CI 0.81-0.92). Conclusions: The presence of a body mass index paradox exists in non-dialysis CKD patients. This risk-factor paradox was an independent predictor of all-cause mortality and may have significant clinical implications relevant to screening, assessment and treatment and requires further study.

Enhancing neural activity to drive respiratory plasticity following cervical spinal cord injury

Cervical spinal cord injury (SCI) results in permanent life-altering sensorimotor deficits, among which impaired breathing is one of the most devastating and life-threatening. While clinical and experimental research has revealed that some spontaneous respiratory improvement (functional plasticity) can occur post-SCI, the extent of the recovery is limited and significant deficits persist. Thus, increasing effort is being made to develop therapies that harness and enhance this neuroplastic potential to optimize long-term recovery of breathing in injured individuals. One strategy with demonstrated therapeutic potential is the use of treatments that increase neural and muscular activity (e.g. locomotor training, neural and muscular stimulation) and promote plasticity. With a focus on respiratory function post-SCI, this review will discuss advances in the use of neural interfacing strategies and activity-based treatments, and highlights some recent results from our own research.

A Review on Locomotor Training after Spinal Cord Injury: Reorganization of Spinal Neuronal Circuits and Recovery of Motor Function

Locomotor training is a classic rehabilitation approach utilized with the aim of improving sensorimotor function and walking ability in people with spinal cord injury (SCI). Recent studies have provided strong evidence that locomotor training of persons with clinically complete, motor complete, or motor incomplete SCI induces functional reorganization of spinal neuronal networks at multisegmental levels at rest and during assisted stepping. This neuronal reorganization coincides with improvements in motor function and decreased muscle cocontractions. In this review, we will discuss the manner in which spinal neuronal circuits are impaired and the evidence surrounding plasticity of neuronal activity after locomotor training in people with SCI. We conclude that we need to better understand the physiological changes underlying locomotor training, use physiological signals to probe recovery over the course of training, and utilize established and contemporary interventions simultaneously in larger scale research studies. Furthermore, the focus of our research questions needs to change from feasibility and efficacy to the following: what are the physiological mechanisms that make it work and for whom? The aforementioned will enable the scientific and clinical community to develop more effective rehabilitation protocols maximizing sensorimotor function recovery in people with SCI.

Functional electrical stimulation: cardiorespiratory adaptations and applications for training in paraplegia

Regular exercise can be broadly beneficial to health and quality of life in humans with spinal cord injury (SCI). However, exercises must meet certain criteria, such as the intensity and muscle mass involved, to induce significant benefits. SCI patients can have difficulty achieving these exercise requirements since the paralysed muscles cannot contribute to overall oxygen consumption. One solution is functional electrical stimulation (FES) and, more importantly, hybrid training that combines volitional arm and electrically controlled contractions of the lower limb muscles. However, it might be rather complicated for therapists to use FES because of the wide variety of protocols that can be employed, such as stimulation parameters or movements induced. Moreover, although the short-term physiological and psychological responses during different types of FES exercises have been extensively reported, there are fewer data regarding the long-term effects of FES. Therefore, the purpose of this brief review is to provide a critical appraisal and synthesis of the literature on the use of FES for exercise in paraplegic individuals. After a short introduction underlying the importance of exercise for SCI patients, the main applications and effects of FES are reviewed and discussed. Major findings reveal an increased physiological demand during FES hybrid exercises as compared with arms only exercises. In addition, when repeated within a training period, FES exercises showed beneficial effects on muscle characteristics, force output, exercise capacity, bone mineral density and cardiovascular parameters. In conclusion, there appears to be promising evidence of beneficial effects of FES training, and particularly FES hybrid training, for paraplegic individuals.

Passive Hind-Limb Cycling Reduces the Severity of Autonomic Dysreflexia After Experimental Spinal Cord Injury

Background. Spinal cord injury (SCI) induces alterations in cardio-autonomic control of which autonomic dysreflexia (AD), a condition characterized by life-threatening hypertension, is arguably the most insidious. Passive hind-limb cycling represents a low-cost therapeutic intervention with demonstrable cardiovascular, sensory, and motor benefits. Objective. To investigate the effect of passive hind-limb cycling on AD in rodents with T3 SCI. Methods. Forty-five male Wistar rats were evenly assigned to either uninjured control (CON), SCI, or SCI plus hind-limb cycling exercise (SCI-EX). At the end of the experimental period (day 32), rats were randomly assigned to stream 1 (n = 24) or stream 2 (n = 21). Stream 1 rats were assessed for AD severity (pressor response to colorectal distension) and were then perfused for tissue dissection and immunohistochemistry. Stream 2 rats underwent excision of the superior mesenteric artery for in vitro myography assessments. Results. From 2 weeks post-SCI onwards, SCI-EX rats exhibited a significant reduction in the pressor response to colorectal distension versus SCI ( P < .001). Reduced AD severity in SCI-EX rats was accompanied by a prevention of the SCI-induced increase in density of CGRP+ afferents in the dorsal horn ( P = .001). Conversely, both SCI and SCI-EX rats exhibited a similar degree of mesenteric endothelial dysfunction and α-adrenoceptor hypersensitivity versus CON. Conclusion. Passive hind-limb cycling reduces the severity of AD in SCI, and is correlated with changes in primary afferent morphology, but has limited effects on the peripheral vasculature.

Energy expenditure and heart rate responses to increased loading in individuals with motor complete spinal cord injury performing body weight-supported exercises

OBJECTIVE

To examine acute metabolic and heart rate responses in individuals with motor complete spinal cord injury (SCI) during stepping and standing with body weight support (BWS).

DESIGN

Cohort study.

SETTING

Therapeutic exercise research laboratory.

PARTICIPANTS

Nonambulatory individuals with chronic, motor complete SCI between T5 and T12 (n=8) and healthy, able-bodied controls (n=8).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Oxygen consumption (V˙o2) and heart rate.

RESULTS

Individuals with motor complete SCI performed standing and stepping exercises in a BWS system with manual assistance of lower body kinematics. V˙o2 and heart rate responses were assessed in relation to level of BWS. Weight support was provided by an overhead lift at high (≥50% BWS) or low (20%-35% BWS) levels during stepping and standing. Although participants with motor complete SCI were unable to stand or step without assistance, levels of V˙o2 and heart rate were elevated by 38% and 37%, respectively, when load was maximized during stepping (ie, low BWS). Participants without an SCI (able-bodied group) had a similar acute response to exercise. None of the participants met the target range for V˙o2 response in any of the tasks. However, stepping was sufficient to enable half of the participants in the SCI group to attain the target range for heart rate response to exercise.

CONCLUSIONS

Individuals with motor complete SCI exhibit cardiovascular responses during body weight-supported exercise. Findings indicate that body weight-supported stepping provides a minimal cardiovascular challenge for individuals with paraplegia. Emphasis on low weight support during locomotor training can trigger additional heart rate adaptations.

Time and Effort Required by Persons with Spinal Cord Injury to Learn to Use a Powered Exoskeleton for Assisted Walking

BACKGROUND

Powered exoskeletons have been demonstrated as being safe for persons with spinal cord injury (SCI), but little is known about how users learn to manage these devices.

OBJECTIVE

To quantify the time and effort required by persons with SCI to learn to use an exoskeleton for assisted walking.

METHODS

A convenience sample was enrolled to learn to use the first-generation Ekso powered exoskeleton to walk. Participants were given up to 24 weekly sessions of instruction. Data were collected on assistance level, walking distance and speed, heart rate, perceived exertion, and adverse events. Time and effort was quantified by the number of sessions required for participants to stand up, walk for 30 minutes, and sit down, initially with minimal and subsequently with contact guard assistance.

RESULTS

Of 22 enrolled participants, 9 screen-failed, and 7 had complete data. All of these 7 were men; 2 had tetraplegia and 5 had motor-complete injuries. Of these, 5 participants could stand, walk, and sit with contact guard or close supervision assistance, and 2 required minimal to moderate assistance. Walk times ranged from 28 to 94 minutes with average speeds ranging from 0.11 to 0.21 m/s. For all participants, heart rate changes and reported perceived exertion were consistent with light to moderate exercise.

CONCLUSIONS

This study provides preliminary evidence that persons with neurological weakness due to SCI can learn to walk with little or no assistance and light to somewhat hard perceived exertion using a powered exoskeleton. Persons with different severities of injury, including those with motor complete C7 tetraplegia and motor incomplete C4 tetraplegia, may be able to learn to use this device.

Differing autonomic responses to dobutamine stress in the presence and absence of myocardial ischaemia

KEY POINTS

Dobutamine stress echocardiography is a validated tool for the non-invasive evaluation of myocardial ischaemia and enables the recording of heart rate variability in non-resting conditions. In this study we determined whether individuals with transient myocardial ischaemia had different autonomic responses to the stress of dobutamine infusion compared to non-ischaemic (normal) responders. Non-ischaemic responders had a residual predominance of parasympathetic over sympathetic activity. However, under conditions of myocardial ischaemia, there was a directionally opposite cardiac autonomic response with a residual increase of sympathetic over parasympathetic modulation. The sympathetic response to dobutamine stress is augmented as the burden of myocardial ischaemia is increased.

ABSTRACT

Cardiac autonomic dysfunction has prognostic significance in patients with coronary artery disease. This investigation aimed to assess changes in autonomic modulation induced by dobutamine stress in the presence and absence of myocardial ischaemia. In total, 314 individuals underwent dobutamine stress echocardiography to detect or exclude myocardial ischaemia. Simultaneous autonomic and haemodynamic data were obtained using a plethysmographic device. Total power spectral density and associated low-frequency (LF) and high-frequency (HF) power spectral components in absolute (ms(2) ) and normalised units (nu) were determined. Participants were categorised as non-ischaemic (NI) or ischaemic (IS) responders. There were no significant differences in LFnu or HFnu between groups at baseline. At peak stress, LFnu decreased from baseline in NI (43 ± 1.8 to 40 ± 1.8%), but increased from baseline in IS responders (39.5 ± 2 to 56 ± 2%, P < 0.05). In contrast, HFnu increased in NI patients (57 ± 1.8 to 60 ± 1.8%) but decreased in IS responders (60.5 ± 2 to 44 ± 2%, P < 0.05). Those with a high ischaemic burden [more than three ischaemic left ventricular (LV) segments] had a greater increase in LFnu (41 ± 4.8 to 65 ± 3.2% vs. 44.8 ± 3.8 to 57.7 ± 3.1%, P < 0.05) and greater decrease in HFnu (59 ± 4.8 to 35 ± 3.2% vs. 55.2 ± 3.8 to 42.3 ± 3.1%, P < 0.05) compared to patients with a low ischaemic burden (1-3 ischaemic LV segments) respectively, at peak stress. In the absence of myocardial ischaemia, dobutamine stress is associated with a residual predominance of parasympathetic over sympathetic activity. Under conditions of ischaemia, there is a directionally opposite autonomic response with a significant residual increase of sympathetic over parasympathetic modulation. This response is augmented as the burden of ischaemia is increased.

Treadmill gait training improves baroreflex sensitivity in Parkinson's disease

BACKGROUND

Partial weight supported treadmill gait training (PWSTT) is widely used in rehabilitation of gait in patient with Parkinson’s Diseases (PD). However, its effect on blood pressure variability (BPV) and baroreflex sensitivity (BRS) in PD has not been studied.

AIM

To evaluate the effect of conventional and treadmill gait training on BPV components and BRS.

METHODS

Sixty patients with idiopathic PD were randomized into three groups. Twenty patients in control group were on only stable medication, 20 patients in conventional gait training (CGT) group (Stable medication with CGT) and 20 patients in PWSTT group (Stable medication with 20 % PWSTT). The CGT and PWSTT sessions were given for 30 min per day, 4 days per week, for 4 weeks (16 sessions). Groups were evaluated in their best ‘ON’ states. The beat-to-beat finger blood pressure (BP) was recorded for 10 min using a Finometer instrument (Finapres Medical Systems, The Netherlands). BPV and BRS results were derived from artifact-free 5-min segments using Nevrocard software.

RESULTS

BRS showed a significant group with time interaction (F = 6.930; p = 0.003). Post-hoc analysis revealed that PWSTT group showed significant improvement in BRS (p < 0.001) after 4 weeks of training. No significant differences found in BPV parameters; systolic BP, diastolic BP, co-variance of systolic BP and low frequency component of systolic BP.

CONCLUSIONS

Four weeks of PWSTT significantly improves BRS in patients with PD. It can be considered as a non-invasive method of influencing BRS for prevention of orthostatic BP fall in patients with PD.

Heart rate response during underwater treadmill training in adults with incomplete spinal cord injury

BACKGROUND

Walking on a submerged treadmill can improve mobility in persons displaying lower limb muscle weakness and balance deficits. Little is known, however, regarding the effect of water treadmill exercise on cardiac performance in persons with incomplete spinal cord injury (iSCI).

OBJECTIVE

To assess heart rate response during underwater treadmill training (UTT) in adults with iSCI.

METHODS

Seven males and 4 females with iSCI (age = 48 ± 13 years; 5 ± 8 years after injury) completed 8 weeks of UTT (3 sessions per week; 3 walks per session) incorporating individually determined walking speeds, personalized levels of body weight unloading, and gradual, alternating increases in speed and duration. Heart rate was monitored during the last 15 seconds of the final 2 minutes of each walk.

RESULTS

Over the course of 3 biweekly periods in which walking speed remained constant, heart rate fell by 7% (7 ± 1 b•min(-1); P < .001) in weeks 2 and 3, 14% (17 ± 6 b•min(-1); P < .001) in weeks 4 and 5, and 17% (21 ± 11 b•min(-1); P < .001) in weeks 6 and 7.

CONCLUSION

In adults with iSCI, progressively greater absolute and relative reductions in submaximal exercise heart rate occurred after 2 months of UTT featuring a systematic increase in training volume.

Clinical treatment of orthostatic hypotension after spinal cord injury with training based on electric uprise bed coupled with remote ECG and BP monitor

BACKGROUND

The treatment for orthostatic hypotension (OH) after spinal cord injury (SCI) is an important part of rehabilitation in late-stage SCI. Electric uprise bed training is a relatively commonly used method in treating OH, and how to carry out uprise bed training safely and effectively is an urgent problem. In the early stage of SCI, we used a remote monitoring system to monitor the whole process of uprise bed training, and we explored a safe and efficient method of electric uprise bed training.

MATERIAL AND METHODS

The experimental group consisted of 36 patients diagnosed with orthostatic hypotension (OH) after SCI and who received training with an electric uprise bed coupled with remote monitoring system, and the control group of 18 subjects who used a traditional training method.

RESULTS

There were no differences in baseline data between the 2 groups. There were no severe symptoms during training in the experimental group, but 3 patients had severe symptoms in the control group. Among the 32 enrolled subjects reaching upright training status within 30 days (17 subjects in the experimental group and 15 subjects in the control group), time interval of training from horizontal position to erect position in the experimental group was 18.00±3.12 days and 21.40±4.95 days in the control group. Time interval in the experimental group was significantly less than in the control group. However, among all 36 subjects, by combining results of follow-up, there was no significant difference of time interval of training from horizontal position to erect position between the experimental group and the control group. In the experimental group 90.52% of patients finished training compared to 78.19% in the control group (P<0.01). After training, values of OCs and OCd of the experimental group were lower than in the control group. There was no significant difference between groups in number of re-diagnosed OH.

CONCLUSIONS

Implementation of training with electric uprise bed coupled with remote monitoring system is generally safe for patients with OH after SCI. For patients who could reach standing training status within 30 days, implementation can improve efficiency of training by shortening time interval of training from horizontal position to erect position. It can increase orthostatic blood pressure change during position change.

Adverse events in cardiovascular-related training programs in people with spinal cord injury: a systematic review

CONTEXT

There are anecdotal reports of adverse events (AEs) associated with exercise in people with spinal cord injury (SCI) and consequent concern by people with SCI and their providers about potential risks of exercise. Enumeration of specific events has never been performed and the extent of risk of exercise to people with SCI is not understood.

OBJECTIVE

To systematically review published evidence to identify and enumerate reports of adverse events or AEs associated with training in persons with SCI.

METHODS

Review was limited to peer-reviewed studies published in English from 1970 to 2011: (1) in adults with SCI, (2) evaluating training protocols consisting of repeated sessions over at least 4 weeks to maintain or improve cardiovascular health, (3) including volitional exercise modalities and functional electrical stimulation (FES)-enhanced exercise modalities, and (4) including a specific statement about AEs. Trained reviewers initially identified a total of 145 studies. After further screening, 38 studies were included in the review. Quality of evidence was evaluated using established procedures.

RESULTS

There were no serious AEs reported. There were no common AEs reported across most types of interventions, except for musculoskeletal AEs related to FES walking. There were few AEs in volitional exercise studies.

CONCLUSION

There is no evidence to suggest that cardiovascular exercise done according to guidelines and established safety precautions is harmful. To improve the strength of these conclusions, future publications should include definition of AEs, information about pre-intervention screening, and statements of the nature and extent of AEs.

The Effect of Treadmill-based Incremental Leg Weight Loading Training on the Balance of Stroke Patients

[Purpose] The purpose of this study was to examine the effect of treadmill-based gait training using incremental weight loading on the ankle of the affected side on hemiplegic stroke patients’ balance. [Subjects] In this study, 30 hemiplegic stroke patients were randomly divided into an incremental weight load group (IWLG, n=15) and a no-load group (NLG, n=15). [Methods] The IWLG performed gait training on treadmills for four weeks wearing a sandbag weighing 3% of the body weight on the affected side ankle, followed by wearing a sandbag weighing 5% of the body weight from the 5th week. The NLG performed similar training without sandbags. [Results] Both the IWLG and the NLG showed significant improvements in balance ability. The IWLG showed a larger decrease in the area and length of movement of the center of pressure in static standing positions after the experiment although the difference was not significant. [Conclusion] We recommend, utilizing the treadmill-based gait training using incremental weight loading on the affected side ankle as a clinical intervention for improving hemiplegic stroke patients’ balance ability.

Treino locomotor com suporte parcial de peso corporal na reabilitação da lesão medular: revisão da literatura

INTRODUÇÃO: O treino locomotor com suporte de peso corporal (TLSP) é utilizado há aproximadamente 20 anos no campo da reabilitação em pacientes que sofrem de patologias neurológicas. O TLSP favorece melhoras osteomusculares, cardiovasculares e psicológicas, pois desenvolve ao máximo o potencial residual do organismo, proporcionando a reintegração na convivência familiar, profissional e social. OBJETIVO: Identificar as principais modalidades de TLSP e seus parâmetros de avaliação com a finalidade de contribuir com o estabelecimento de evidências confiáveis para as práticas reabilitativas de pessoas com lesão medular. MATERIAIS E MÉTODOS: Foram analisados artigos originais, publicados entre 2000 e 2011, que envolvessem treino de marcha após a lesão medular, com ou sem suporte parcial de peso corporal, e tecnologias na assistência do treino, como biofeedback e estimulação elétrica funcional, entre outras. RESULTADOS: A maioria dos participantes dos estudos era do sexo masculino; os níveis de lesão variavam de C3 a L3; ASIA teve pontuações de A a D; os tempos de lesão variaram entre 0,3 meses a 33 anos. Também se verificou que não há consenso em relação ao protocolo de TLSP. CONCLUSÃO: O treino locomotor com suporte de peso corporal mostra-se viável na reabilitação de pacientes que sofrem de uma patologia neurológica como a lesão medular. Independentemente do protocolo de treino utilizado, os benefícios referentes ao aumento da força muscular, manutenção ou aumento da densidade óssea, diminuição da frequência cardíaca e aumento do condicionamento físico estão presentes

Cardiovascular function after spinal cord injury: prevalence and progression of dysfunction during inpatient rehabilitation and 5 years following discharge

BACKGROUND

Autonomic dysfunction after spinal cord injury (SCI) is an under-researched area when compared with motor and sensory dysfunction. Cardiovascular autonomic dysfunction is a particular concern, leading to impaired control of blood pressure and heart rate.

OBJECTIVES

(1) To determine the prevalence of hypotension in individuals with SCI during and after rehabilitation; (2) To investigate changes in cardiovascular variables during and after rehabilitation; (3) To evaluate the influence of personal and lesion characteristics on cardiovascular variables.

METHODS

Cardiovascular variables (resting systolic [SAP] and diastolic [DAP] arterial pressures and resting [HRrest] and peak heart rates [HRpeak]) were measured on 5 test occasions: start of inpatient rehabilitation, 3 months later, at discharge, and at 1 and 5 years after discharge. The time course and effects of personal and lesion characteristics on cardiovascular variables were studied using multilevel regression analyses.

RESULTS

The prevalence of hypotension was unchanged during rehabilitation and for 5 years after discharge. Odds for hypotension were highest in those with cervical and high thoracic lesions, younger individuals, and men. DAP increased during the 5 years after discharge. HRrest decreased during and after rehabilitation. SAP, DAP, HRrest, and HRpeak were lowest in those with cervical and high thoracic lesions. SAP and DAP increased with age; HRpeak decreased with age.

CONCLUSIONS

These longitudinal data provide normative values for blood pressure and heart rate changes with time after injury according to lesion and personal characteristics. These results can be used to guide clinical practice and place changes in cardiovascular function caused by interventions in perspective.

Effect of partial weight-supported treadmill gait training on balance in patients with Parkinson disease

OBJECTIVE

To investigate the role of conventional gait training and partial weight-supported treadmill gait training (PWSTT) in improving the balance of patients with Parkinson disease (PD).

DESIGN

Prospective randomized controlled design.

SETTING

National-level university tertiary hospital for mental health and neurosciences.

PATIENTS

Sixty patients with PD fulfilling the United Kingdom Brain Bank PD diagnostic criteria were recruited from the neurology outpatient department and movement disorder clinic.

METHODOLOGY

The patients were randomly assigned into 3 equal groups: (1) a control group that only received a stable dosage of dopaminomimetic drugs; (2) a conventional gait training (CGT) group that received a stable dosage of dopaminomimetic drugs and conventional gait training; and (3) a PWSTT group that received a stable dosage of dopaminomimetic drugs and PWSTT with unloading of 20% of body weight. The sessions for the CGT and PWSTT groups were provided for 30 minutes per day, 4 days per week, for 4 weeks (16 sessions).

OUTCOME MEASURES

The Unified Parkinson Disease Rating Scale (UPDRS) motor score, dynamic posturography, Berg Balance Scale, and Tinetti performance-oriented mobility assessment (POMA) were used as main outcome measures.

RESULTS

A significant interaction effect was observed in the UPDRS motor score, mediolateral index, Berg Balance Scale, limits of stability (LOS) total score, POMA gait score, and balance score. Post-hoc analysis showed that in comparison with the control group, the PWSTT group had a significantly better UPDRS motor score, balance indices, LOS in 8 directions, POMA gait, and balance score. The CGT group had a significantly better POMA gait score compared with control subjects. Compared with the CGT group, the PWSTT group had a significantly better UPDRS motor score, mediolateral index, POMA gait score, and LOS total score.

CONCLUSION

PWSTT may be a better interventional choice than CGT for gait and balance rehabilitation in patients with PD.

Disordered cardiovascular control after spinal cord injury

Damage to the spinal cord disrupts autonomic pathways, perturbing cardiovascular homeostasis. Cardiovascular dysfunction increases with higher levels of injury and greater severity. Disordered blood pressure control after spinal cord injury (SCI) has significant ramifications as cord-injured people have an increased risk of developing heart disease and stroke; cardiovascular dysfunction is currently a leading cause of death among those with SCI. Despite the clinical significance of abnormal cardiovascular control following SCI, this problem has been generally neglected by both the clinical and research community. Both autonomic dysreflexia and orthostatic hypotension are known to prevent and delay rehabilitation, and significantly impair the overall quality of life after SCI. Starting with neurogenic shock immediately after a higher SCI, ensuing cardiovascular dysfunctions include orthostatic hypotension, autonomic dysreflexia and cardiac arrhythmias. Disordered temperature regulation accompanies these autonomic dysfunctions. This chapter reviews the human and animal studies that have furthered our understanding of the pathophysiology and mechanisms of orthostatic hypotension, autonomic dysreflexia and cardiac arrhythmias. The cardiovascular dysfunction that occurs during sexual function and exercise is elaborated. New awareness of cardiovascular dysfunction after SCI has led to progress toward inclusion of this important autonomic problem in the overall assessment of the neurological condition of cord-injured people.

Atypical autonomic dysreflexia during robotic-assisted body weight supported treadmill training in an individual with motor incomplete spinal cord injury

CONTEXT/OBJECTIVE

A 41-year-old man with a history of C6 American Spinal Injury Association (ASIA) Impairment Scale (AIS) C spinal cord injury (SCI), enrolled in an Institutional Review Board (IRB)-approved, robotic-assisted body weight-supported treadmill training (BWSTT), and aquatic exercise research protocol developed asymptomatic autonomic dysreflexia (AD) during training. Little information is available regarding the relationship of robotic-assisted BWSTT and AD.

FINDINGS

After successfully completing 36 sessions of aquatic exercise, he reported exertional fatigue during his 10th Lokomat intervention and exhibited asymptomatic or silent AD during this and the three subsequent BWSTT sessions. Standard facilitators of AD were assessed and no obvious irritant identified other than the actual physical exertion and positioning required during robotic-assisted BWSTT.

CONCLUSIONS/CLINICAL RELEVANCE

Increased awareness of potential silent AD presenting during robotic assisted BWSTT training for individuals with motor incomplete SCI is required as in this case AD clinical signs were not concurrent with occurrence. Frequent vital sign assessment before, during, and at conclusion of each BWSTT session is strongly recommended.

Locomotor training: as a treatment of spinal cord injury and in the progression of neurologic rehabilitation

Scientists, clinicians, administrators, individuals with spinal cord injury (SCI), and caregivers seek a common goal: to improve the outlook and general expectations of the adults and children living with neurologic injury. Important strides have already been accomplished; in fact, some have labeled the changes in neurologic rehabilitation a "paradigm shift." Not only do we recognize the potential of the damaged nervous system, but we also see that "recovery" can and should be valued and defined broadly. Quality-of-life measures and the individual's sense of accomplishment and well-being are now considered important factors. The ongoing challenge from research to clinical translation is the fine line between scientific uncertainty (ie, the tenet that nothing is ever proven) and the necessary burden of proof required by the clinical community. We review the current state of a specific SCI rehabilitation intervention (locomotor training), which has been shown to be efficacious although thoroughly debated, and summarize the findings from a multicenter collaboration, the Christopher and Dana Reeve Foundation's NeuroRecovery Network.