Search

Objective: The purpose of this systematic review was to characterize methodologies reported in the literature to elicit and record pudendal somatosensory evoked potentials (SEPs) in human adults., Methods: We conducted an electronic literature search in MEDLINE, Embase, CENTRAL, and CINAHL for studies that elicited pudendal SEPs via electrical stimulation and recorded responses though electroencephalography. From included studies, we extracted methodological details of how the SEPs were evoked and recorded., Results: 132 studies were included in our review. The majority of participants were male (n = 6742/8526, 79%). Almost all studies stimulated the dorsal nerve of penis/clitoris. Stimulus parameters varied, with most standardizing stimulus intensity to 2-4x perceptual threshold, pulse duration to 0.1-0.2 ms, and frequency to 3 Hz. The number of stimuli recorded varied by clinical population., Conclusions: Our results demonstrate the inconsistencies of pudendal SEP methodology in the literature, with the majority (77%) of publications not reporting enough detail to reasonably replicate their protocol. Most research to date has been conducted in males, highlighting the paucity of female pelvic neurophysiology research., Significance: We propose a Pudendal SEP Reporting Checklist for adequate reporting of pudendal SEP protocols. Optimal sex- and patient-specific methodologies to investigate all branches of the pudendal nerve need to be established., (Copyright © 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Cervical or upper-thoracic spinal cord injury (SCI, ≥T6) often leads to low resting blood pressure (BP) and impaired cardiovascular responses to acute exercise due to disrupted supraspinal sympathetic drive. Epidural spinal cord stimulation (invasive, ESCS) and transcutaneous spinal cord stimulation (non-invasive, TSCS) have previously been used to target dormant sympathetic circuits and modulate cardiovascular responses. This case series compared the effects of cardiovascular-optimised ESCS and TSCS versus sham ESCS and TSCS on modulating cardiovascular responses and improving submaximal upper-body exercise performance in individuals with SCI. Seven males with a chronic, motor-complete SCI between C6 and T4 underwent a mapping session to identify cardiovascular responses to spinal cord stimulation. Subsequently, four participants (two ESCS and two TSCS) completed submaximal exercise testing. Stimulation parameters (waveform, frequency, intensity, epidural electrode array configuration, and transcutaneous electrode locations in the lumbosacral region) were optimised to elevate cardiovascular responses (CV-SCS). A sham condition (SHAM-SCS) served as a comparison. Participants performed arm-crank exercise to exhaustion at a fixed workload corresponding to above ventilatory threshold, on separate days, with CV-SCS or SHAM-SCS. At rest, CV-SCS increased BP and predicted left ventricular cardiac contractility and total peripheral resistance. During exercise, CV-SCS increased time to exhaustion and peak oxygen pulse (a surrogate for stroke volume), relative to SHAM-SCS. Ratings of perceived exertion also tended to be lower with CV-SCS than SHAM-SCS. Comparable improvements in time to exhaustion with ESCS and TSCS suggest that both approaches could be promising ergogenic aids to support exercise performance or rehabilitation, along with reducing fatigue during activities of daily living in individuals with SCI., Competing Interests: AK reports having several patents related to neuromodulation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hodgkiss, Williams, Shackleton, Samejima, Balthazaar, Lam, Krassioukov and Nightingale.)

Context: Recovery of seated balance is a rehabilitation priority for people with motor-complete spinal cord injury (mcSCI). Previous research has demonstrated that people with mcSCI can voluntarily engage their trunk muscles during different exercise programs that have the potential to improve seated balance control. Boxing and battle rope exercises could offer another opportunity to improve seated balance for people with mcSCI, but it is unknown if this type of exercise engages trunk musculature and challenges seated balance., Objective: To describe the movement patterns of people with mcSCI compared to controls by characterizing the muscle activation patterns and kinematics of the trunk and upper-body during boxing and battle rope exercise., Design: Cross-sectional study., Participants: 4 males with mcSCI between C7-T9, and 4 able-bodied controls., Methods: Participants performed different boxing and battle rope exercises while kinematics and electromyography (EMG) from the trunk and arms were recorded., Outcome Measures: Trunk EMG amplitude, trunk and arm joint angles, and trunk curvature., Results: Boxing and battle ropes elicited higher relative EMG activity in people with mcSCI compared to controls ( P  < 0.001). Participants with mcSCI had similar upper-limb kinematics during the exercises to controls, but demonstrated reduced trunk rotation and increased trunk curvature., Conclusions: These findings suggest that boxing and battle rope can elicit trunk activity in people with mcSCI, though they may adopt increased trunk curvatures. Future research should explore if such exercise programs may improve seated balance in people with mcSCI.

Introduction: Peripheral nerve stimulation can modulate the excitability of corticospinal pathways of muscles in the upper and lower limbs. Further, the pattern of peripheral nerve stimulation (continuous vs. intermittent) may be an important factor determining the modulation of this corticospinal excitability. The pelvic floor muscles (PFM) are crucial for maintaining urinary continence in humans, and share spinal segmental innervation with the tibial nerve. We explored the idea of whether the neuromodulatory effects of tibial nerve stimulation (TibNS) could induce effects on somatic pathways to the PFM. We evaluated the effects of two patterns of stimulation (intermittent vs. continuous) on corticospinal excitability of the PFM compared to its effect on the abductor hallucis (AH) muscle (which is directly innervated by the tibial nerve). We hypothesized that intermittent TibNS would increase, while continuous stimulation would decrease, the excitability of both AH and PFM., Methods: Twenty able-bodied adults (20-33 years of age) enrolled in this study. TibNS was delivered either intermittently (1 ms pulses delivered at 30Hz with an on:off duty cycle of 600:400 ms, for 60 min), or continuously (1 ms pulses delivered at 30Hz for 36 min) just above the motor threshold of the AH. We randomized the order of the stimulation pattern and tested them on separate days. We used surface electromyography (EMG) to record motor-evoked responses (MEP) in the PFM and AH following transcranial magnetic stimulation (TMS). We generated stimulus-response (SR) curves to quantify the changes in peak-to-peak MEP amplitude relative to TMS intensity to assess changes in corticospinal excitability pre- and post-stimulation., Results and Conclusion: We found that TibNS increased corticospinal excitability only to AH, with no effects in PFM. There was no difference in responses to continuous vs. intermittent stimulation. Our results indicate a lack of effect of TibNS on descending somatic pathways to the PFM, but further investigation is required to explore other stimulation parameters and whether neuromodulatory effects may be spinal in origin., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Eginyan, Zhou, Williams and Lam.)

Context: Autonomic dysreflexia (AD), characterized by a transient increase in systolic blood pressure (BP), is experienced by individuals with spinal cord injury (SCI) and can be purposefully induced ('boosting') to counteract autonomic dysfunction that impairs cardiovascular responses to exercise. Herein, we demonstrate the impact of unintentional boosting observed during cardiopulmonary exercise testing (CPET) in an inactive male with SCI (C5, motor-complete)., Findings: On two separate occasions the individual performed a standard arm-crank CPET (1-min stages, 7W increase in resistance) following by a longer CPET (4-min stages, 12W increase in resistance), both to volitional exhaustion. The second CPET was performed to confirm the accuracy of exercise intensity prescription and verify peak exercise parameters. Immediately following the second CPET on the initial visit, the individual reported symptoms of AD, verified as a 58mmHg increase in systolic BP from baseline. Relative to the first CPET, performed only 35 min earlier, there were pronounced differences in peak exercise responses. In comparison to the longer CPET performed on the second visit without a concomitant episode of AD (thereby controlling for the type of CPET protocol administered), peak exercise outcomes were considerably elevated: power output (Δ19W), oxygen uptake (Δ3.61 ml·   kg· -1 min -1 ), ventilation (Δ11.4 L ·min -1 ) and heart rate (Δ9 b·min -1 )., Conclusion/clinical Relevance: This case raises important considerations around the nuances of CPET in this population. In individuals susceptible to BP instability, the physiologically boosted state may explain a significant proportion of the variance in peak aerobic capacity and should be closely monitored before and after clinical CPET.

Introduction: The pelvic floor muscles (PFM) are active during motor tasks that increase intra-abdominal pressure, but little is known about how the PFM respond to dynamic activities, such as gait. The purpose of this study was to characterize and compare PFM activity during walking and jogging in continent adults across the entire gait cycle., Methods: 17 able-bodied individuals (8 females) with no history of incontinence participated in this study. We recorded electromyography (EMG) from the abdominal muscles, gluteus maximus (GM), and PFM while participants performed attempted maximum voluntary contractions (aMVC) of all muscles and completed 60-70 strides in four gait conditions: slow walk (1 km/h); regular walk (self-selected comfortable pace); transition walk (self-selected fastest walking pace); jog (same speed as transition walking). We quantified activity throughout the whole gait cycle (%aMVC GC ) and during periods of bursting (%aMVC BR ) for each participant, and analyzed the timing of PFM bursting periods to explore when the PFM were most active in the gait cycle. We also conducted a phase metric analysis on the PFM and GM burst timings. We performed a Spearman's rank-order correlation to examine the effect of speed on %aMVC GC , %aMVC BR , and phase metric score, and used the Wilcoxon Signed-Rank test to evaluate the effect of gait modality, matched for speed (walking vs. jogging), on these variables., Results: The PFM were active throughout the gait cycle, with bursts typically occurring during single-leg support. The PFM and GM were in phase for 44-69% of the gait cycle, depending on condition. There was a positive correlation between gait speed and both %aMVC GC and %aMVC BR ( p < 0.001). Phase metric scores were significantly higher during jogging than transition walking ( p = 0.005), but there was no difference between gait modality on %aMVC GC or %aMVC BR ( p = 0.059). Where possible we disaggregated data by sex, although were unable to make statistical comparisons due to low sample sizes., Conclusion: The PFM are active during walking and jogging, with greater activity at faster speeds and with bursts in activity around single-leg support. The PFM and GM co-activate during gait, but are not completely in phase with each other., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Williams, Sato-Klemm, Deegan, Eginyan and Lam.)

Background: There is emerging evidence that pelvic floor muscle training (PFMT) may be useful for treating some urogenital conditions in people with spinal cord injury (SCI). Future clinical investigations would benefit from understanding the extent to which people with SCI are aware of and practicing PFMT, and their attitude toward this therapy., Objective: The goal of this study was to assess the knowledge, attitudes, and practices related to PFMT among people with SCI., Methods: We distributed an internet survey internationally via SCI related organizations for 2 months. We used descriptive statistics to summarize each survey item, and Chi-square and Mann-Whitney U tests to explore the differences in results between sexes and level of motor-function., Results: Complete data from 153 respondents were analyzed. Sixty-two percent of respondents were female and 71% reported having complete paralysis. More than half of respondents reported being aware of PFMT (63%); more females than males reported knowledge of PFMT ( p = 0.010). Females ( p = 0.052) and people with partial paralysis ( p = 0.008) reported a stronger belief that they would benefit from PFMT. Few people with SCI had practiced PFMT (20%), and of those who practiced, most of them had SCI resulting in partial paralysis ( p = 0.023)., Conclusions: While people with SCI may be aware of and have favorable attitudes toward PFMT, few had practiced PFMT and there were notable differences in attitudes toward PFMT depending on the sex and level of motor function of the respondents., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sato-Klemm, Williams, Mortenson and Lam.)

Objective: The primary aim of this study was to determine the feasibility of delivering an exoskeleton-assisted walking intervention targeting lower urinary tract function in people with motor-complete spinal cord injury. Secondary aims were to determine if exoskeleton walking activates the pelvic floor muscles, and compare 2 exoskeleton programmes regarding lower urinary tract function., Design: Randomized pilot trial., Subjects: Adults with motor-complete spinal cord injury at or above T10., Methods: Participants were randomized to receive Ekso or Lokomat training. Feasibility outcomes included recruitment rate, adherence, and adverse events. Pelvic floor muscle electromyography was recorded during walking. Urodynamic studies, 3-day bladder diary, and Qualiveen-30 were administered pre- and post-training., Results: Twelve people were screened and 6 people enrolled in the study. Two subjects withdrew from unrelated reasons. There was one adverse event. Pelvic floor muscle activity was greater in the Ekso group. Lower urinary tract function did not clearly change in either group., Conclusion: This pilot study demonstrates the feasibility of delivering an exoskeleton training programme targeting lower urinary tract function. Ekso-walking elicits pelvic floor muscle activity, but it remains unclear how locomotor training impacts lower urinary tract function.

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.

Spinal cord injury (SCI) leads to severe impairment in cardiovascular control, commonly manifested as a rapid, uncontrolled rise in blood pressure triggered by peripheral stimuli-a condition called autonomic dysreflexia. The objective was to demonstrate the translational potential of noninvasive transcutaneous stimulation (TCS) in mitigating autonomic dysreflexia following SCI, using pre-clinical evidence and a clinical case report. In rats with SCI, we show that TCS not only prevents the instigation of autonomic dysreflexia, but also mitigates its severity when delivered during an already-triggered episode. Furthermore, when TCS was delivered as a multisession therapy for 6 weeks post-SCI, the severity of autonomic dysreflexia was significantly reduced when tested in the absence of concurrent TCS. This treatment effect persisted for at least 1 week after the end of therapy. More importantly, we demonstrate the clinical applicability of TCS in treatment of autonomic dysreflexia in an individual with cervical, motor-complete, chronic SCI. We anticipate that TCS will offer significant therapeutic advantages, such as obviating the need for surgery resulting in reduced risk and medical expenses. Furthermore, this study provides a framework for testing the potential of TCS in improving recovery of other autonomic functions such lower urinary tract, bowel, and sexual dysfunction following SCI., (© 2021. The Author(s).)

Individuals classified clinically as having a motor-complete spinal cord injury (mcSCI) should lack voluntary motor function below their injury level. Neurophysiological assessments using electromyography (EMG) and transcranial magnetic stimulation (TMS), however, have demonstrated that persons with mcSCI retain limited cortical descending innervation and voluntary activation of muscles below their level of injury, including muscles of the trunk and lower limb. We explored the possibility of whether there is also preserved innervation of the pelvic floor muscles (PFM) in persons with mcSCI. The PFM are controlled by widespread cortical and subcortical areas and typically coactivated with trunk and gluteal muscles to maintain continence and regulate intra-abdominal pressure. Nine mcSCI and eight control subjects participated in this cross-sectional study. Surface EMG was used to record activity in the PFM. Data were recorded while participants attempted various maneuvers of the trunk and pelvis. We also applied TMS at incrementing levels of intensity over the primary motor cortex area to record motor evoked potentials (MEPs) in the PFM. When performing the maneuvers, activation of the PFM was possible in all controls and the majority of SCI participants. However, the PFM were only activated in the SCI participants during maneuvers that engaged other trunk muscles, however. MEP responses in the PFM were also elicited in all controls and SCI participants, but MEP response characteristics were significantly altered in the SCI group. Our results suggest that persons with mcSCI retain some residual innervation of the PFM after injury, possibly via indirect cortical descending pathways.

Background: There is some evidence that upper-body training modalities can improve not only aerobic capacity but also seated balance in people with spinal cord injury (SCI), even in those classified with motor-complete paralysis above T6. Here, we evaluated the effect of arm crank ergometry (ACE) "spin" training on trunk muscle recruitment and its effects on seated balance and aerobic capacity., Methods: Eight individuals with high-level complete and 6 with either a low-level complete or a motor-incomplete SCI participated in this study. Participants completed 5 weeks of a group ACE "spin" training protocol which featured modulations in cadence and resistance as well as back-supported and unsupported bouts. Surface electromyography was used to confirm trunk muscle recruitment during unsupported ACE. Changes in aerobic capacity (peak oxygen consumption) and seated balance control (center of pressure parameters) were assessed at pre- and post-intervention., Results: Unsupported ACE was effective for eliciting trunk muscle activity (P < .05). Following training, peak oxygen consumption significantly improved by an average of 16% (P = .005). Static sitting balance significantly improved from pre- to post-intervention, but only when tested with eyes closed as measured by a reduction in area (P = .047) and velocity of center of pressure (P = .013). No significant changes were observed in static sitting balance with eyes open or in dynamic sitting balance., Conclusion: Group ACE "spin" classes may benefit not only aerobic fitness but also static seated balance control in people with SCI., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Many people with motor-incomplete spinal cord injury (m-iSCI) experience difficulty navigating obstacles, such as curbs and stairs. The ability to relearn walking skills may be limited by proprioceptive deficits. The purpose of this study was to determine the capacity of participants to acquire a precision walking skill, and to evaluate the influence of proprioceptive deficits on the skill acquisition in individuals with m-iSCI. Sixteen individuals with m-iSCI and eight controls performed a precision walking task that required matching their foot height to a target during the swing phase. Proprioceptive deficits were quantified at the hip and knee for joint position and movement detection sense. Participants completed 600 steps of training with visual feedback. Pretraining and posttraining tests were conducted without visual feedback, along with a transfer test with an ankle weight. Posttraining and transfer tests were repeated 1 day later. Participants returned to the laboratory 1 wk later to repeat the training. Performance was calculated as the vertical distance between the target and actual foot height for each step. The posttraining and transfer performances were similar between groups. However, participants with m-iSCI had a slower rate of acquisition to achieve a similar performance level compared with controls. Acquisition rate and posttraining performance of the precision walking task were related to lower limb joint position sense among SCI participants. Although they can achieve a similar level of performance in a precision walking task, proprioceptive deficits impair the rate of learning among individuals with m-iSCI compared with able-bodied controls. NEW & NOTEWORTHY People with motor-incomplete spinal cord injuries are able to achieve the same level of performance accuracy on a precision walking task as able-bodied controls; however, the rate of learning is slower, indicating that more practice is required to stabilize performance. Our findings also show a relationship between impaired sensory function and reduced accuracy when performing a precision walking task after spinal cord injury.

Background: The trunk muscles are critical for postural control. Recent neurophysiological studies have revealed sparing of trunk muscle function in individuals with spinal cord injury (SCI) classified with thoracic or cervical motor-complete injuries. These findings raise the possibility for recruiting and retraining this spared trunk function through rehabilitation. Robotic gait training devices may provide a means to promote trunk muscle activation. Thus, the objective of this study was to characterize and compare the activation of the trunk muscles during walking with two robotic gait training devices (Ekso and Lokomat) in people with high thoracic motor-complete SCI., Methods: Participants with chronic motor-complete paraplegia performed 3 speed-matched walking conditions: Lokomat-assisted walking, Ekso-assisted walking overground, and Ekso-assisted walking on a treadmill. Surface electromyography (EMG) signals were recorded bilaterally from the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) muscles., Results: Greater recruitment of trunk muscle EMG was elicited with Ekso-assisted walking compared to the Lokomat. Similar levels of trunk EMG activation were observed between Ekso overground and Ekso on the treadmill, indicating that differences between Ekso and Lokomat could not be attributed to the use of a hand-held gait aid. The level of trunk EMG activation during Lokomat walking was not different than that recorded during quiescent supine lying., Conclusions: Ekso-assisted walking elicits greater activation of trunk muscles compared to Lokomat-assisted walking, even after controlling for the use of hand-held assistive devices. The requirement of the Ekso for lateral weight-shifting in order to activate each step could lead to better postural muscle activation.