Translating promising strategies for bowel and bladder management in spinal cord injury

Rapid-Onset, Short-Duration Induction of Colorectal Contractions in Anesthetized, Adult, Male Rats

Substantial clinical and preclinical evidence indicates that transient receptor potential vanilloid 1 (TRPV1) receptors are expressed on terminals of colorectal chemoreceptors and mechanoreceptors and are involved in various rectal hypersensitivity disorders with common features of colorectal overactivity. These stimulatory properties of TRPV1 receptors on colorectal function suggested that brief stimulation of TRPV1 might provide a means of pharmacologically activating the colorectum to induce defecation in patients with an "unresponsive" colorectum. The current studies explored the basic features of TRPV1 receptor-induced contractions of the colorectum in anesthetized rats with and without acute spinal cord injury (aSCI). Cumulative concentration-response curves to intrarectal (IR) capsaicin (CAP) solutions (0.003%-3.0%) were performed in anesthetized aSCI and spinal intact rats. CAP produced an "inverted U," cumulative concentration-response curve with a threshold for inducing colorectal contractions at 0.01% and a peak response at 0.1% and slight decreases in responses up to 3%. Decreases in responses with concentrations >0.1% are due to a rapid desensitization (i.e., ≤30 minutes) of TRPV1 receptors to each successive dose. Desensitization appeared fully recovered within 24 hours in spinal intact rats. Colorectal contractions were completely blocked by atropine, indicating a reflexogenic activation of parasympathetic neurons, and responses were completely unaffected by a neurokinin 2 receptor antagonist, indicating that release of neurokinin A from afferent terminals and subsequent direct contractions of the smooth muscle was not involved. IR administration of three other TRPV1 receptor agonists produced similar results as CAP. SIGNIFICANCE STATEMENT: Individuals with spinal cord injury often lose control of defecation. Time-consuming bowel programs using digital stimulation of the rectum are used to empty the bowel. This study shows that intrarectal administration of the transient receptor potential vanilloid 1 (TRPV1) receptor agonist, capsaicin, can induce rapid-onset, short-duration colorectal contractions capable of inducing defecation in spinal cord injured and intact rats. Therefore, TRPV1 agonists show promise as potential therapeutics to induce defecation in individuals with neurogenic bowel.

Progress and research trends in neurogenic bladder after spinal cord injury bibliometric analysis based on web of science database: An observational study

Neurogenic bladder (NB) is a significant complication that often occurs after spinal cord injury. It results from urinary dysfunction caused by the injury, disrupting the normal neural control of the bladder and urethra. Symptoms of NB can include urinary frequency, urgency, incontinence, and retention, all of which can greatly impact the quality of life of affected individuals. While there are articles and reviews on NB, fewer specifically address NB following spinal cord injury. This study examined 1095 publications from January 1, 2000, to March 27, 2024, in the Web of Science core database using bibliometric software like VOSviewer, CiteSpace, and Bibliometrics. The analysis revealed an increasing trend in the number of publications, with the United States and China leading in research output. Professor Jeremy B. Myers from the University of Utah had the highest number of publications, while the University of Michigan and the University of Pittsburgh were the institutions with the most publications. The journal Neurourology and Urodynamics had the highest number of articles, and common keywords included management, quality of life, and dysfunction, highlighting key areas of focus for scholars.

Mapping the Iceberg of Autonomic Recovery: Mechanistic Underpinnings of Neuromodulation following Spinal Cord Injury

Spinal cord injury leads to disruption in autonomic control resulting in cardiovascular, bowel, and lower urinary tract dysfunctions, all of which significantly reduce health-related quality of life. Although spinal cord stimulation shows promise for promoting autonomic recovery, the underlying mechanisms are unclear. Based on current preclinical and clinical evidence, this narrative review provides the most plausible mechanisms underlying the effects of spinal cord stimulation for autonomic recovery, including activation of the somatoautonomic reflex and induction of neuroplastic changes in the spinal cord. Areas where evidence is limited are highlighted in an effort to guide the scientific community to further explore these mechanisms and advance the clinical translation of spinal cord stimulation for autonomic recovery.

Implementing Lived Experience Workshops in Regional Areas of British Columbia to Enhance Clinicians' Confidence in Spinal Cord Injury Care: An Evaluation

In British Columbia (BC), there are challenges accessing specialized spinal cord injury care and resources. This paper evaluated the impact of spinal cord injury health educational workshops delivered in regional communities that were informed by persons with lived experience. A community survey was conducted with 44 persons with lived experience in a BC region to identify priority SCI health-related topics. Twenty-five topics were ranked from 1-14, with bowel and bladder management ranked 1 and 4, sexual health ranked 5, and pressure injuries ranked 7. Clinical perspectives on the priorities were collected from 102 clinicians in the BC region, who independently ranked 14 of these SCI topics and considered the former 4 topics to be lower clinical priority (ranked 11-14). These priorities informed a series of SCI clinical education workshops held at healthcare facilities in three regional cities. The goals were to improve clinicians' knowledge and confidence levels when managing spinal cord injury health and to facilitate person-centred care. Positive feedback demonstrated that educational workshops supported by lived experience perspectives effectively enhanced the clinicians' understanding of spinal cord injury and their priorities. Future plans include engaging more administrators as part of this initiative and conducting workshops in other regions of BC.

Priorities, needs and willingness of use of nerve stimulation devices for bladder and bowel function in people with spinal cord injury (SCI): an Australian survey

STUDY DESIGN

Anonymous online survey OBJECTIVES: To investigate the priorities, needs and willingness to adopt nerve stimulation devices for managing neurogenic bladder and bowel function in people with spinal cord injury (SCI) living in Australia.

SETTING

Online survey of people living with SCI in Australia.

METHODS

This anonymous online survey used Qualtrics and was advertised via standard communication channels, such as advocacy groups representing the SCI community in Australia, social media, attending SCI sporting events and by word-of-mouth.

RESULTS

Responses from 62 individuals (32% female, 68% male) were included. Bladder emptying through urethra without catheter was the highest priority for bladder function. Reducing time required for bowel routines and constipation were the top priorities regarding bowel function. The highest concern for internal/implanted devices was the 4% chance of device surgical removal, while wearing wires under the clothes was the main concern for external devices. 53% of respondents were willing to trial an implanted nerve stimulation device, while 70% would trial an external device to improve and gain independence in bladder and bowel function.

CONCLUSION

The findings of this study highlighted the potential role in which nerve stimulation can have in addressing bladder and bowel dysfunction in people with SCI, and have also identified that there was a need for Australian physiotherapists to evaluate their role in bladder and bowel dysfunction. Results from this study can help guide further research in nerve stimulation devices for bladder and bowel dysfunction in people with SCI.

SPONSORSHIP

n/a.

A narrative review on the use of near-infrared spectroscopy to monitor bladder volume and in vitro validation approaches

Background and Objective

Current guidelines for patients with neurogenic bladder (NB) dysfunction suggest the use of self-intermittent catheterization with adherence to catheterization timers. Due to biorhythmic variability, unpredictable voiding times may occur. As a result, many patients abstain from extended social or work activities, turn to more secluded lifestyles, and generally experience a decrease in quality of life. Being able to know when to void is essential for patients with NB dysfunction. To solve the problem of variable void timings, wearable devices using near-infrared spectroscopy (NIRS) have been emergent and showed potential for bladder volume monitoring. Therefore, in this review, we provided a comprehensive overview of research which implemented NIRS for bladder volume monitoring, and discussed how the researchers validated their device by in-vitro methods and suggested a potential validation approach.

Methods

A literature search using PubMed and Google Scholar was conducted on February 2023. Publications involving bladder volume monitoring incorporating NIRS technique with in-vitro validation was considered for review.

Key Content and Findings

Due to the novelty of NIRS being applied to bladder monitoring, there are a few possibilities to effectively validate this technique through in-vitro methods. Ballistics gel, which has been proven to be a versatile material for applications involving ultrasound, could be a suitable material when constructing a bladder phantom for in-vitro validation of NIRS technology.

Conclusions

By outlining a more standardized in-vitro validation model based on ballistics gel, we hope to facilitate development in this field towards a more accurate and robust NIRS-based bladder monitoring device.

Hybrid Bladder Phantom to Validate Next-Generation Optical Wearables for Neurogenic Bladder Volume Monitoring

PURPOSE

The development of optics-based wearables for bladder volume monitoring has emerged as a significant topic in recent years. Given the innovative nature of this technology, there is currently no bladder phantom available to effectively validate these devices against more established gold standards, such as ultrasound. In this study, we showcase and demonstrate the performance of our hybrid bladder phantom by using an optical device and making comparisons with ultrasound.

METHODS

A series of validation tests, including phantom repeatability, ultrasound scanning, and an optical test, were performed. A near-infrared optical device was utilized to conduct diffuse optical spectroscopy (DOS). Machine learning models were employed to construct predictive models of volume using optical signals.

RESULTS

The size and position of an embedded balloon, serving as an analog for the bladder, were shown to be consistent when infused with 100 mL to 350 mL of water during repeatability testing. For DOS data, we present 7 types of machine learningbased models based on different optical signals. The 2 best-performing models demonstrated an average absolute volume error ranging from 12.7 mL to 19.0 mL.

CONCLUSION

In this study, we introduced a hybrid bladder phantom designed for the validation of near-infrared spectroscopy-based bladder monitoring devices in comparison with ultrasound techniques. By offering a reproducible and robust validation tool, we aim to support the advancement of next-generation optical wearables for bladder volume monitoring.

Current insights into the management of spinal cord injury

Background

Traumatic spinal cord injury (SCI) is a serious disorder that results in severe impairment of neurological function as well as disability, ultimately reducing a patient's quality of life. The pathophysiology of SCI involves a primary and secondary phase, which causes neurological injury.

Methods

Narrative review on current clinical management of spinal cord injury and emerging therapies.

Results

This review explores the management of SCI through early decompressive surgery, optimizing mean arterial pressure, steroid therapy and focused rehabilitation. These management strategies reduce secondary injury mechanisms to prevent the propagation of further neurological damage. The literature regarding emerging research is also explored in cell-based, gene, pharmacological and neuromodulation therapies, which aim to repair the spinal cord following the primary injury mechanism.

Conclusions

Outcomes for patients with SCI can be enhanced and improved if primary and secondary phases of SCI can be addressed.

Detrusor underactivity is associated with metabolic syndrome in aged primates

Lower urinary tract (LUT) dysfunction is prevalent in the elderly population, and clinical manifestations include urinary retention, incontinence, and recurrent urinary tract infections. Age-associated LUT dysfunction is responsible for significant morbidity, compromised quality of life, and rising healthcare costs in older adults, but its pathophysiology is not well understood. We aimed to investigate the effects of aging on LUT function by urodynamic studies and metabolic markers in non-human primates. Adult (n = 27) and aged (n = 20) female rhesus macaques were evaluated by urodynamic and metabolic studies. Cystometry showed detrusor underactivity (DU) with increased bladder capacity and compliance in aged subjects. Metabolic syndrome indicators were present in the aged subjects, including increased weight, triglycerides, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and high sensitivity C-reactive protein (hsCRP), whereas aspartate aminotransferase (AST) was unaffected and the AST/ALT ratio reduced. Principal component analysis and paired correlations showed a strong association between DU and metabolic syndrome markers in aged primates with DU but not in aged primates without DU. The findings were unaffected by prior pregnancies, parity, and menopause. Our findings provide insights into possible mechanisms for age-associated DU and may guide new strategies to prevent and treat LUT dysfunction in older adults.

Prescribing patterns for treating common complications of spinal cord injury

OBJECTIVE

The purpose of this study was to find the most and least commonly prescribed medications for treating secondary health complications associated with spinal cord injury (SCI); and determine overall polypharmacy rates and risk factors associated with it.

DESIGN

Observational design, cross-sectional analysis.

SETTING

Community; Canada.

PARTICIPANTS

Individuals with spinal cord injury (n = 108).

RESULTS

A total of 515 prescriptions were issued to the sample comprising 213 different medications to treat 10 SCI-related complications. Forty-five (45%) participants were prescribed >5 medications concurrently. No associations were found between the number of drugs taken and age, sex, level of injury, completeness of injury, time since injury, or cause of injury. The most commonly treated complications included pain (56.5%), muscle spasms (54%) and urinary tract infections (43%). Anti-convulsants (pregabalin, gabapentin), anti-spasmodics (baclofen, diazepam) and nitrofurantoins (Macrobid) were the most commonly prescribed medications to treat each of the three conditions, respectively. Thirty five percent of the total sample received a combination of two or more analgesics including fourth-line agents in the opiate class (hydromorphone, hydrocodone and morphine). Similarly, some participants were prescribed general muscle relaxants and cephalosporins for treatment of muscle spasms and urinary tract infections, respectively, that are generally not recommended in SCI patients. We compare these prescribing patterns with the available clinical practice guidelines and highlight areas where the prescriptions fall outside the recommended clinical practice while considering the complexity of medication management in SCI.

CONCLUSION

Medication management in SCI is complex. Tools are required that enable prescribers to choose evidence-based medical regimens and deprescribe potentially inappropriate medications for their patients with SCI.

Effects of non-invasive spinal cord stimulation on lower urinary tract, bowel, and sexual functions in individuals with chronic motor-complete spinal cord injury: Protocol for a pilot clinical trial

INTRODUCTION

Electrical spinal cord neuromodulation has emerged as a leading intervention for restoring autonomic functions, such as blood pressure, lower urinary tract (LUT), bowel, and sexual functions, following spinal cord injury (SCI). While a few preliminary studies have shown the potential effect of non-invasive transcutaneous spinal cord stimulation (tSCS) on autonomic recovery following SCI, the optimal stimulation parameters, as well as real-time and long-term functional benefits of tSCS are understudied. This trial entitled "Non-invasive Neuromodulation to Treat Bladder, Bowel, and Sexual Dysfunction following Spinal Cord Injury" is a pilot trial to examine the feasibility, dosage effect and safety of tSCS on pelvic organ function for future large-scale randomized controlled trials.

METHODS AND ANALYSIS

Forty eligible participants with chronic cervical or upper thoracic motor-complete SCI will undergo stimulation mapping and assessment batteries to determine the real-time effect of tSCS on autonomic functions. Thereafter, participants will be randomly assigned to either moderate or intensive tSCS groups to test the dosage effect of long-term stimulation on autonomic parameters. Participants in each group will receive 60 minutes of tSCS per session either twice (moderate) or five (intensive) times per week, over a period of six weeks. Outcome measures include: (a) changes in bladder capacity through urodynamic studies during real-time and after long-term tSCS, and (b) resting anorectal pressure determined via anorectal manometry during real-time tSCS. We also measure assessments of sexual function, neurological impairments, and health-related quality of life using validated questionnaires and semi-structured interviews.

ETHICS AND DISSEMINATION

Ethical approval has been obtained (CREB H20-01163). All primary and secondary outcome data will be submitted to peer-reviewed journals and disseminated among the broader scientific community and stakeholders.

Traumatic spinal cord injury and the contributions of the post-injury microbiome

Spinal cord injuries are an enormous burden on injured individuals and their caregivers. The pathophysiological effects of injury are not limited to the spine and limb function, but affect numerous body systems. Growing observations in human studies and experimental models suggest that the gut microbiome is altered following spinal cord injury. Given the importance of signals derived from the gut microbiome for host physiology, it is possible that injury-triggered dysbiosis subsequently affects aspects of recovery. Here, we review emerging literature on the role of the microbiome following spinal cord injury. Specifically, we highlight findings from both human and experimental studies that correlate taxonomic changes to aspects of injury recovery. Examination of both observational and emerging interventional studies supports the notion that future therapeutic avenues for spinal cord injury pathologies may lie at the interface of the host and indigenous microbes.

Experiences of patients and their partners with sexual problems after spinal cord injury: A phenomenological qualitative study

Objective: This study aimed to examine the experiences of patients and their partners about their sexual lives after Spinal Cord Injury (SCI).Design: This qualitative study was based on Heidegger's hermeneutic phenomenological approach.Setting: The Physical Medicine and Rehabilitation Outpatient Clinic of a city hospital in the Central Anatolia Region in Turkey.Participants: The study consisted of seven female and six male patients with spinal cord injury and their partners.Outcome measures: The textual analysis was carried out in three stages: (1) a naive reading, (2) a structural analysis, and (3) a comprehensive understanding of the text including a discussion. The sample size was calculated by using the criterion sampling technique.Results: As a result of the in-depth interviews with individuals with SCI about their sexual experiences, five themes were derived: (1) first confrontation with SCI, (2) experienced sexual problems, (3) coping, (4) partners' views on sexual problems, and (5) other people.Conclusion: It was found that the sex life of individuals with SCI was negatively affected, they were left helpless in dealing with their problems, and that some patients had difficulties in coping with this condition.

Thoracolumbar epidural stimulation effects on bladder and bowel function in uninjured and chronic transected anesthetized rats

Pre-clinical studies have shown that spinal cord epidural stimulation (scES) at the level of pelvic and pudendal nerve inputs/outputs (L5-S1) alters storage and/or emptying functions of both the bladder and bowel. The current mapping experiments were conducted to investigate scES efficacy at the level of hypogastric nerve inputs/outputs (T13-L2) in male and female rats under urethane anesthesia. As found with L5-S1 scES, T13-L2 scES at select frequencies and intensities of stimulation produced an increase in inter-contraction interval (ICI) in non-injured female rats but a short-latency void in chronic T9 transected rats, as well as reduced rectal activity in all groups. However, the detrusor pressure during the lengthened ICI (i.e., urinary hold) remained at a low pressure and was not elevated as seen with L5-S1 scES, an effect that's critical for translation to the clinic as high fill pressures can damage the kidneys. Furthermore, T13-L2 scES was shown to stimulate voiding post-transection by increasing bladder activity while also directly inhibiting the external urethral sphincter, a pattern necessary to overcome detrusor-sphincter dyssynergia. Additionally, select scES parameters at T13-L2 also increased distal colon activity in all groups. Together, the current findings suggest that optimization of scES for bladder and bowel will likely require multiple electrode cohorts at different locations that target circuitries coordinating sympathetic, parasympathetic and somatic outputs.

Multisite Transcutaneous Spinal Stimulation for Walking and Autonomic Recovery in Motor-Incomplete Tetraplegia: A Single-Subject Design

OBJECTIVE

This study investigated the effect of cervical and lumbar transcutaneous spinal cord stimulation (tSCS) combined with intensive training to improve walking and autonomic function after chronic spinal cord injury (SCI).

METHODS

Two 64-year-old men with chronic motor incomplete cervical SCI participated in this single-subject design study. They each underwent 2 months of intensive locomotor training and 2 months of multisite cervical and lumbosacral tSCS paired with intensive locomotor training.

RESULTS

The improvement in 6-Minute Walk Test distance after 2 months of tSCS with intensive training was threefold greater than after locomotor training alone. Both participants improved balance ability measured by the Berg Balance Scale and increased their ability to engage in daily home exercises. Gait analysis demonstrated increased step length for each individual. Both participants experienced improved sensation and bowel function, and 1 participant eliminated the need for intermittent catheterization after the stimulation phase of the study.

CONCLUSION

These results suggest that noninvasive spinal cord stimulation might promote recovery of locomotor and autonomic functions beyond traditional gait training in people with chronic incomplete cervical SCI.

IMPACT

Multisite transcutaneous spinal stimulation may induce neuroplasticity of the spinal networks and confer functional benefits following chronic cervical SCI.

Optimization and assessment of a novel gastric electrode anchoring system designed to be implanted by minimally invasive surgery

A novel electrode anchoring design and its implantation procedure, aiming for a minimally invasive solution for gastric electrical stimulation, are presented. The system comprises an anchor made of a flexible body embedding two needle-shaped electrodes. The electrodes can easily switch from a parallel position - to pierce the stomach - to a diverging position - enabling them to remain firmly anchored into the muscular layer of the stomach. Key device parameters governing anchoring stability were assessed on a traction test bench, and optimal values were derived. The device was then implanted in six dogs by open surgery to assess its anchoring durability in vivo. Computed tomography images showed that the electrodes remained well placed within the dogs' gastric wall over the entire assessment period (more than one year). Finally, a prototype of a surgical tool for the minimally invasive device placement was manufactured, and the anchoring procedure was tested on a dog cadaver, providing the proof of concept of the minimally invasive implantation procedure. The use of our electrode anchoring system in long-term gastric electrical stimulation is promising in terms of implantation stability (the anchor withstands a force up to 0.81 N), durability (the anchor remains onto the stomach over one year) and minimal invasiveness of the procedure (the diameter of the percutaneous access is smaller than 12 mm). Moreover, the proposed design could have clinical applications in other hollow organs, such as the urinary bladder.

Neurogenic Bowel in Acute Rehabilitation Following Spinal Cord Injury: Impact of Laxatives and Opioids

Objective: To explore the association between bowel dysfunction and use of laxatives and opioids in an acute rehabilitation setting following spinal cord injury (SCI). Methods: Data was collected regarding individuals with acute traumatic/non-traumatic SCI over a two-year period (2012–2013) during both the week of admission and discharge of their inpatient stay. Results: An increase in frequency of bowel movement (BM) (p = 0.003) and a decrease in frequency of fecal incontinence (FI) per week (p < 0.001) between admission and discharge was found across all participants. There was a reduction in the number of individuals using laxatives (p = 0.004) as well as the number of unique laxatives taken (p < 0.001) between admission and discharge in our cohort. The number of individuals using opioids and the average dose of opioids in morphine milligram equivalents (MME) from admission to discharge were significantly reduced (p = 0.001 and p = 0.02, respectively). There was a positive correlation between the number of laxatives and frequency of FI at discharge (r = 0.194, p = 0.014), suggesting that an increase in laxative use results in an increased frequency of FI. Finally, there was a significant negative correlation between average dose of opioids (MME) and frequency of BM at discharge, confirming the constipating effect of opioids (r = −0.20, p = 0.009).

Caring behaviors, moral sensitivity, and emotional intelligence in intensive care nurses: A descriptive study

PURPOSE

To evaluate the relationship of caring behaviors with moral sensitivity, emotional intelligence and descriptive characteristics in intensive care nurses.

METHOD

Descriptive study. The sample of this study consisted of 156 nurses. The data were collected using introductory information form, caring behaviors inventory, moral sensitivity questionnaire, and emotional intelligence scale. The factors affecting caring behavior were determined using stepwise multiple linear regression.

FINDING

It was determined that high education level, working in shifts, as well as appraisal of emotion subscale of emotional intelligence scale and also autonomy, expressing benevolence, and following praxis subscales of moral sensitivity questionnaire were high predictors for caring behaviors.

PRACTICE IMPLICATIONS

Descriptive characteristics, moral sensitivity, and emotional intelligence are related to high caring behavior in intensive care nurses.

Restoring both continence and micturition after chronic spinal cord injury by pudendal neuromodulation

Neurogenic bladder management after spinal cord injury (SCI) is very challenging. Daily urethral catheterization is most commonly used to empty the bladder, which causes frequent infections of the lower urinary tract. This study reports a novel idea to restore both continence and micturition after SCI by an implantable pudendal nerve stimulator (PNS). The PNS was surgically implanted in four cats with complete SCI at T9-T10 spinal level and tested weekly for 13-14 weeks under awake conditions. These chronic SCI cats consistently exhibited large residual bladder volumes (average 40-50 ml) due to their inability to void efficiently, while urine leakage also occurred frequently. The PNS which consisted of stimulating the pudendal nerve at 20-30 Hz to trigger a spinal reflex bladder contraction and at the same time blocking the pudendal nerves bilaterally with 10 kHz stimulation to relax the external urethral sphincter and reduce the urethral outlet resistance successfully induced highly efficient (average 80-100%), low pressure (<50 cmH₂O) voiding. The PNS at 5 Hz also promoted urine storage by inhibiting reflex bladder activity and increasing bladder capacity. At the end of 14-week chronic testing, low pressure efficient voiding induced by PNS was further confirmed under anesthesia by directly measuring voiding pressure using a bladder catheter inserted through the bladder dome. This study demonstrated the efficacy and safety of the PNS in awake chronic SCI cats, suggesting that a novel neuroprosthesis can be developed for humans to restore bladder function after SCI by stimulating and/or blocking the pudendal nerves.

Pharmacological Management of Neurogenic Bowel Dysfunction after Spinal Cord Injury and Multiple Sclerosis: A Systematic Review and Clinical Implications

Neurogenic bowel dysfunction (NBD) is a common problem for people with spinal cord injury (SCI) and multiple sclerosis (MS), which seriously impacts quality of life. Pharmacological management is an important component of conservative bowel management. The objective of this study was to first assemble a list of pharmacological agents (medications and medicated suppositories) used in current practice. Second, we systematically examined the current literature on pharmacological agents to manage neurogenic bowel dysfunction of individuals specifically with SCI or MS. We searched Medline, EMBASE and CINAHL databases up to June 2020. We used the GRADE System to provide a systematic approach for evaluating the evidence. Twenty-eight studies were included in the review. We found a stark discrepancy between the large number of agents currently prescribed and a very limited amount of literature. While there was a small amount of literature in SCI, there was little to no literature available for MS. There was low-quality evidence supporting rectal medications, which are a key component of conservative bowel care in SCI. Based on the findings of the literature and the clinical experience of the authors, we have provided clinical insights on proposed treatments and medications in the form of three case study examples on patients with SCI or MS.

Bladder and bowel responses to lumbosacral epidural stimulation in uninjured and transected anesthetized rats

Spinal cord epidural stimulation (scES) mapping at L5-S1 was performed to identify parameters for bladder and bowel inhibition and/or contraction. Using spinally intact and chronic transected rats of both sexes in acute urethane-anesthetized terminal preparations, scES was systematically applied using a modified Specify 5-6-5 (Medtronic) electrode during bladder filling/emptying cycles while recording bladder and colorectal pressures and external urethral and anal sphincter electromyography activity. The results indicate frequency-dependent effects on void volume, micturition, bowel peristalsis, and sphincter activity just above visualized movement threshold intensities that differed depending upon neurological intactness, with some sex-dependent differences. Thereafter, a custom-designed miniature 15-electrode array designed for greater selectivity was tested and exhibited the same frequency-dependent urinary effects over a much smaller surface area without any concurrent movements. Thus, select activation of autonomic nervous system circuitries with scES is a promising neuromodulation approach for expedient translation to individuals with SCI and potentially other neurologic disorders.

Effect of Different Forms of Activity-Based Recovery Training on Bladder, Bowel, and Sexual Function After Spinal Cord Injury

OBJECTIVES

To investigate whether the urogenital and bowel functional gains previously demonstrated post-locomotor step training after chronic spinal cord injury could have been derived due to weight-bearing alone or from exercise in general.

DESIGN

Prospective cohort study; pilot trial with small sample size.

SETTING

Urogenital and bowel scientific core facility at a rehabilitation institute and spinal cord injury research center in the United States.

PARTICIPANTS

Men and women (N=22) with spinal cord injury (American Spinal Injury Association Impairment Scale grades of A-D) participated in this study.

INTERVENTIONS

Approximately 80 daily 1-hour sessions of either stand training or nonweight-bearing arm crank ergometry. Comparisons were made with previously published locomotor training data (step; N=7).

MAIN OUTCOME MEASURES

Assessments at both pre- and post-training timepoints included cystometry for bladder function and International Data Set Questionnaires for bowel and sexual functions.

RESULTS

Cystometry measurements revealed a significant decrease in bladder pressure and limited improvement in compliance with nonweight-bearing exercise but not with standing. Although International Data Set questionnaires revealed profound bowel dysfunction and marked deficits in sexual function pretraining, no differences were identified poststand or after nonweight-bearing exercise.

CONCLUSIONS

These pilot trial results suggest that, although stand and weight-bearing alone do not benefit pelvic organ functions after spinal cord injury, exercise in general may contribute at least partially to the lowering of bladder pressure and the increase in compliance that was seen previously with locomotor training, potentially through metabolic, humoral, and/or cardiovascular mechanisms. Thus, to maximize activity-based recovery training benefits for functions related to storage and emptying, an appropriate level of sensory input to the spinal cord neural circuitries controlling bladder and bowel requires task-specific stepping.

Management of urinary and bowel dysfunction in rabbit model of spinal cord injury using Schwann cells and muscle progenitors: functional study and evidence for novel mechanism of action

PURPOSE

We tried to investigate the role of Schwann and satellite cells in the treatment of neurogenic bladder and bowel dysfunction; following spinal cord injury in the rabbit model.

METHODS

Twelve male New Zealand rabbits underwent induction of neurogenic bladder by spinal cord injury. Rabbits underwent the fiber tractography analysis to confirm the induction of spinal cord injury. Then, animals were randomly divided into two groups. In group I (n = 4), Schwann cells were obtained from autologous peroneal nerve. In group II (n = 4), the co-culture of nerve-muscle cells was obtained from autologous peroneal nerve and quadriceps muscle. Animals in the control group (n = 4) did not undergo any rehabilitation therapy. One and 4 months after injection of cells into the external anal sphincter, electromyography, urethral pressure profiles, urodynamic studies, voiding cystourethrogram, and manometry was performed to confirm the efficacy of treatment in short- (1 month) and long-term (4 months) follow-ups.

RESULTS

The investigations validated that no statistically significant difference was detected between the two experimental groups in a short-term follow-up (p-value > 0.05). However, the functional features were improved in group II in long-term follow-up. In both groups, the external anal sphincter contracted in response to electrical signals delivered to the muscle. However, more signals were detected in group II in electromyography evaluation. The immunohistochemical staining demonstrated that the histological features of the bladder and spinal cord were more satisfactory in group II in all follow-ups compared to group I, in terms of less edema, inflammation, presence of progenitor cells, and expression of muscle and nerve markes.

CONCLUSION

Our results suggested that the injection of nerve-muscle co-culture cells into the external anal sphincter may be a helpful tactic for ameliorating the urological complications; following spinal cord injury induction in the rabbit model.

Needs, priorities, and attitudes of individuals with spinal cord injury toward nerve stimulation devices for bladder and bowel function: a survey

Study Design:

Survey.

Objectives:

To investigate the needs and priorities of people with spinal cord injury for managing neurogenic bladder and bowel function and to determine their willingness to adopt neuromodulation interventions for these functions.

Methods:

Anonymous online survey. It was advertised by word-of-mouth by community influencers and social media, and by advertisement in newsletters of advocacy groups.

Results:

Responses from 370 individuals (27% female, 73% male) were included. Bladder emptying without catheters was the top priority for restoring bladder function, and maintaining fecal continence was the top priority for restoring bowel function. The biggest concerns regarding external stimulation systems were wearing a device with wires connecting to electrodes on the skin and having to don and doff the system daily as needed. The biggest concerns for implanted systems were the chances of experiencing problems with the implant that required a revision surgery or surgical removal of the whole system. Respondents were willing to accept an external (61%) or implanted (41%) device to achieve improved bladder or bowel function.

Conclusions:

Bladder and bowel dysfunction remain important unmet challenges for individuals living with SCI who answered our survey. These individuals are willing to accept some potential risks of nerve stimulation approaches given potential benefits. Additional consumer input is critical for guiding both research and translation to clinical use and personalized medicine.

Spinal cord stimulation for the restoration of bladder function after spinal cord injury

Spinal cord injury (SCI) results in the inability to empty the bladder voluntarily, and neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia (DSD) negatively impact both the health and quality of life of persons with SCI. Current approaches to treat bladder dysfunction in persons with SCI, including self-catheterisation and anticholinergic medications, are inadequate, and novel approaches are required to restore continence with increased bladder capacity, as well as to provide predictable and efficient on-demand voiding. Improvements in bladder function following SCI have been documented using a number of different modalities of spinal cord stimulation (SCS) in both persons with SCI and animal models, including SCS alone or SCS with concomitant activity-based training. Improvements include increased volitional voiding, voided volumes, bladder capacity, and quality of life, as well as decreases in NDO and DSD. Further, SCS is a well-developed therapy for chronic pain, and existing Food And Drug Administration (FDA)-approved devices provide a clear pathway to sustainable commercial availability and impact. However, the effective stimulation parameters and the appropriate timing and location of stimulation for SCS-mediated restoration of bladder function require further study, and studies are needed to determine underlying mechanisms of action.

Development of a novel neurogenic bowel patient reported outcome measure: the Spinal Cord Injury Patient Reported Outcome Measure of Bowel Function & Evacuation (SCI-PROBE)

STUDY DESIGN

Outcome measure item generation and reduction.

OBJECTIVES

To develop a patient reported outcome measure (PROM) addressing the impact of neurogenic bowel dysfunction (NBD) on individuals living with traumatic or nontraumatic spinal cord injury (SCI).

SETTING

Tertiary rehabilitation center in Toronto, Canada.

METHODS

A PROM based on the International Classification of Functioning, Disability and Health (ICF) framework was developed using the following steps: (a) item generation, (b) item refinement through iterative review, (c) completion of items by individuals living with SCI and NBD followed by cognitive interviewing, and (d) further item refinement, item reduction, and construction of the preliminary PROM.

RESULTS

Following initial item generation and iterative review, the investigative team agreed on 55 initial items. Cognitive interviewing, additional revisions, and item reduction yielded an instrument comprised of 35 items; while ensuring at least two items were retained for each of the 16 previously identified challenges of living with NBD following the onset of a SCI. Scoring for the preliminary PROM ranges from 0 to 140.

CONCLUSIONS

A preliminary PROM informed by the ICF for assessing the impact of NBD post-SCI has been devised, which can be used to inform clinicians and decision-makers on optimal ways to treat this serious secondary health complication. Future work will assess the validity and clinimetric properties of the PROM.

Incidence, prognosis, and risk factors for bladder and bowel dysfunction due to incidental dural tears in lumbar microendoscopic surgery

BACKGROUND CONTEXT

Despite the common occurrence of incidental dural tears, the incidence and prognosis of bladder and bowel dysfunction (BBD) due to incidental dural tears in lumbar spinal surgery are not well known because of the lack of reported cases.

PURPOSE

To analyze the incidence, prognosis, and risk factors for BBD after lumbar microendoscopic surgery with or without incidental dural tears.

STUDY DESIGN/SETTING

A retrospective cohort study.

PATIENT SAMPLE

We analyzed 2,421 patients who underwent lumbar microendoscopic surgery and investigated patients with BBD after an incidental durotomy during surgery.

OUTCOME MEASURES

Patients were divided into three groups on the basis of dysuria and defecation disorders: severe BBD, mild BBD, and no BBD. The post void residual volumes before and after surgery were compared using an ultrasound bladder scanner or bladder catheterization after confirmation of urination. Bowel dysfunction was evaluated by subjective symptomatic deterioration and the increase in the frequency and duration of postoperative medical care.

METHODS

Risk factors for BBD were analyzed using surgical video documentation to determine the dural tear site and cauda equina exposure from the dural sac. Patients with BBD were prospectively followed up for prognosis determination. The chi-square test was used to compare the incidence of BBD between patients with dural tears and those without. Propensity score-adjusted logistic regression analysis was performed to evaluate the effects of various factors on the incidence of postoperative BBD.

RESULTS

The incidence of dural tears was 6.9% (168/2,421). The overall incidence of BBD was 3.0% (73/2,421), while the incidences of BBD (mild+severe BBD) and severe BBD due to incidental dural tears were 1.2% (30/2,421) and 0.8% (20/2,421), respectively. The incidence of BBD in patients with dural tears and those without tears was 17.9% [30/168] and 1.9% [43/2,253; p<.001]), respectively. BBD rates at 1 week, 1 month, 3 months, 6 months, and 1 year after surgery were 64.0%, 44.0%, 40.0%, 28.0%, and 13.6%, respectively. Logistic regression analysis revealed that the male sex (odds ratio [OR], 4.20), dural tears in the central area (OR, 10.15), and exposure of the cauda equina (OR, 51.04) were significant risk factors.

CONCLUSIONS

The incidence of dural tears in lumbar microendoscopic surgeries are associated with an increased incidence of BBD. The recovery rate for BBD due to incidental dural tears is generally good; however, some patients experience long-term symptoms. Clinicians should be aware that incidental dural tears with cauda equina exposure can increase the risk of BBD.

Recommendations for evaluation of neurogenic bladder and bowel dysfunction after spinal cord injury and/or disease

Objective: To provide an overview of clinical assessments and diagnostic tools, self-report measures (SRMs) and data sets used in neurogenic bladder and bowel (NBB) dysfunction and recommendations for their use with persons with spinal cord injury /disease (SCI/D).Methods: Experts in SCI/D conducted literature reviews, compiled a list of NBB related assessments and measures, reviewed their psychometric properties, discussed their use in SCI/D and issued recommendations for the National Institutes of Health (NIH), National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDEs) guidelines.Results: Clinical assessments included 15 objective tests and diagnostic tools for neurogenic bladder and 12 for neurogenic bowel. Following a two-phase evaluation, eight SRMs were selected for final review with the Qualiveen and Short-Form (SF) Qualiveen and the Neurogenic Bowel Dysfunction Score (NBDS) being recommended as supplemental, highly-recommended due to their strong psychometrics and extensive use in SCI/D. Two datasets and other SRM measures were recommended as supplemental.Conclusion: There is no one single measure that can be used to assess NBB dysfunction across all clinical research studies. Clinical and diagnostic tools are here recommended based on specific medical needs of the person with SCI/D. Following the CDE for SCI studies guidelines, we recommend both the SF-Qualiveen for bladder and the NBDS for bowel as relatively short measures with strong psychometrics. Other measures are also recommended. A combination of assessment tools (objective and subjective) to be used jointly across the spectrum of care seems critical to best capture changes related to NBB and develop better treatments.

Spinal cord injury leads to atrophy in pelvic ganglia neurons

Among the most devastating sequelae of spinal cord injury (SCI) are genitourinary and gastrointestinal dysfunctions. Post-ganglionic neurons in pelvic ganglia (PG) directly innervate and regulate the function of the lower urinary tract (LUT), bowel, and sexual organs. A better understanding of how SCI affects PG neurons is essential to develop therapeutic strategies for devastating gastrointestinal and genitourinary complications ensuing after injury. To evaluate the impact of SCI on the morphology of PG neurons, we used a well- characterized rat model of upper thoracic SCI (T3 transection) that causes severe autonomic dysfunction. Using immunohistochemistry for neuronal markers, the neuronal profile size frequency distribution was quantified at one-, four-, and eight-weeks post SCI using recursive translation. Our investigation revealed an SCI-dependent leftward shift in neuronal size (i.e. atrophy), observable as early as one-week post injury. However, this effect was more pronounced at four and eight-weeks post-SCI. These findings demonstrate the first characterization of SCI-associated temporal changes in morphology of PG neurons and warrant further investigation to facilitate development of therapeutic strategies for recovery of autonomic functions following SCI.

Chronic, Twice-Daily Dosing of an NK2 Receptor Agonist [Lys5,MeLeu9,Nle10]-NKA(4-10), Produces Consistent Drug-Induced Micturition and Defecation in Chronic Spinal Rats

Acute administration of [Lys5,Me,Leu9,Nle10]-NKA(4-10) (LMN-NKA) produces contractions of the detrusor and rectum with voiding in intact and acutely spinal cord injured (SCI) rats. In the current study, the ability of LMN-NKA (10 μg/kg or 100 μg/kg, subcutaneous [SC], twice a day [bid]) or vehicle to induce voiding and defecation in chronic SCI rats was examined across 30 days. After the last day of administration, voiding response rates and bladder pressure (BP) responses to LMN-NKA (intravenous [IV] and SC) were evaluated under anesthesia. In conscious rats, LMN-NKA (100 μg/kg) produced dose-dependent micturition within 5 min, with response rates >90%, and voiding efficiency >80% in males and >60% in females, which remained stable across the 1-month test period. Similarly, LMN-NKA administration rapidly induced defecation, which also remained stable. Under anesthesia, LMN-NKA increased BP, voiding efficiency, and voiding response rates, which reached 100% at 3 and 10 μg/kg IV in males and females, respectively. SC administration produced 100% response rates in males (30 μg/kg) but only 71% in females (100 μg/kg). Efficacy in rats chronically treated with LMN-NKA was similar to naïve and vehicle-treated rats, except for reduced voiding efficiency in chronically dosed female rats (100 μg/kg). No differences in bladder weights or collagen-to-smooth muscle ratios in histological sections were seen between the groups. Thus neither tolerance, nor sensitization, to LMN-NKA-induced micturition and defecation occurs with chronic administration in rats with chronic SCI. Efficacy was higher in male than in female rats.

Gastrointestinal dysfunction after spinal cord injury

The gastrointestinal tract of vertebrates is a heterogeneous organ system innervated to varying degrees by a local enteric neural network as well as extrinsic parasympathetic and sympathetic neural circuits located along the brainstem and spinal axis. This diverse organ system serves to regulate the secretory and propulsive reflexes integral to the digestion and absorption of nutrients. The quasi-segmental distribution of the neural circuits innervating the gastrointestinal (GI) tract produces varying degrees of dysfunction depending upon the level of spinal cord injury (SCI). At all levels of SCI, GI dysfunction frequently presents life-long challenges to individuals coping with injury. Growing attention to the profound changes that occur across the entire physiology of individuals with SCI reveals profound knowledge gaps in our understanding of the temporal dimensions and magnitude of organ-specific co-morbidities following SCI. It is essential to understand and identify these broad pathophysiological changes in order to develop appropriate evidence-based strategies for management by clinicians, caregivers and individuals living with SCI. This review summarizes the neurophysiology of the GI tract in the uninjured state and the pathophysiology associated with the systemic effects of SCI.

Ultracompliant Carbon Nanotube Direct Bladder Device

The bladder, stomach, intestines, heart, and lungs all move dynamically to achieve their purpose. A long-term implantable device that can attach onto an organ, sense its movement, and deliver current to modify the organ function would be useful in many therapeutic applications. The bladder, for example, can suffer from incomplete contractions that result in urinary retention with patients requiring catheterization. Those affected may benefit from a combination of a strain sensor and electrical stimulator to better control bladder emptying. The materials and design of such a device made from thin layer carbon nanotube (CNT) and Ecoflex 00-50 are described and demonstrate its function with in vivo feline bladders. During bench-top characterization, the resistive and capacitive sensors exhibit stability throughout 5000 stretching cycles under physiology conditions. In vivo measurements with piezoresistive devices show a high correlation between sensor resistance and volume. Stimulation driven from platinum-silicone composite electrodes successfully induce bladder contraction. A method for reliable connection and packaging of medical grade wire to the CNT device is also presented. This work is an important step toward the translation of low-durometer elastomers, stretchable CNT percolation, and platinum-silicone composite, which are ideal for large-strain bioelectric applications to sense or modulate dynamic organ states.

Recommendations for evaluation of bladder and bowel function in pre-clinical spinal cord injury research

Objective: In order to encourage the inclusion of bladder and bowel outcome measures in preclinical spinal cord injury (SCI) research, this paper identifies and categorizes 1) fundamental, 2) recommended, 3) supplemental and 4) exploratory sets of outcome measures for pre-clinical assessment of bladder and bowel function with broad applicability to animal models of SCI.Methods: Drawing upon the collective research experience of autonomic physiologists and informed in consultation with clinical experts, a critical assessment of currently available bladder and bowel outcome measures (histological, biochemical, in vivo functional, ex vivo physiological and electrophysiological tests) was made to identify the strengths, deficiencies and ease of inclusion for future studies of experimental SCI.Results: Based upon pre-established criteria generated by the Neurogenic Bladder and Bowel Working Group that included history of use in experimental settings, citations in the literature by multiple independent groups, ease of general use, reproducibility and sensitivity to change, three fundamental measures each for bladder and bowel assessments were identified. Briefly defined, these assessments centered upon tissue morphology, voiding efficiency/volume and smooth muscle-mediated pressure studies. Additional assessment measures were categorized as recommended, supplemental or exploratory based upon the balance between technical requirements and potential mechanistic insights to be gained by the study.Conclusion: Several fundamental assessments share reasonable levels of technical and material investment, including some that could assess bladder and bowel function non-invasively and simultaneously. Such measures used more inclusively across SCI studies would advance progress in this high priority area. When complemented with a few additional investigator-selected study-relevant supplemental measures, they are highly recommended for research programs investigating the efficacy of therapeutic interventions in preclinical animal models of SCI that have a bladder and/or bowel focus.

Emergence of Epidural Electrical Stimulation to Facilitate Sensorimotor Network Functionality After Spinal Cord Injury

BACKGROUND

Traumatic spinal cord injury (SCI) disrupts signaling pathways between the brain and spinal networks below the level of injury. In cases of severe SCI, permanent loss of sensorimotor and autonomic function can occur. The standard of care for severe SCI uses compensation strategies to maximize independence during activities of daily living while living with chronic SCI-related dysfunctions. Over the past several years, the research field of spinal neuromodulation has generated promising results that hold potential to enable recovery of functions via epidural electrical stimulation (EES).

METHODS

This review provides a historical account of the translational research efforts that led to the emergence of EES of the spinal cord to enable intentional control of motor functions that were lost after SCI. We also highlight the major limitations associated with EES after SCI and propose future directions of spinal neuromodulation research.

RESULTS

Multiple, independent studies have demonstrated return of motor function via EES in individuals with chronic SCI. These enabled motor functions include intentional, controlled movement of previously paralyzed extremities, independent standing and stepping, and increased grip strength. In addition, improvements in cardiovascular health, respiratory function, body composition, and urologic function have been reported.

CONCLUSIONS

EES holds promise to enable functions thought to be permanently lost due to SCI. However, EES is currently restricted to scientific investigation in humans with SCI and requires further validation of factors such as safety and efficacy before clinical translation.

Investigating neurogenic bowel in experimental spinal cord injury: where to begin?

The devastating losses following traumatic spinal cord injury (SCI) encompass the motor, sensory and autonomic nervous systems. Neurogenic bowel is a slow transit colonic dysfunction marked by constipation, rectal evacuation difficulties, decreased anorectal sensation, fecal incontinence or some combination thereof. Furthermore, neurogenic bowel is one of the most prevalent comorbidities of SCI and is recognized by afflicted individuals and caregivers as a lifelong physical and psychological challenge that profoundly affects quality of life. The restoration of post-injury control of movement has received considerable scientific scrutiny yet the daily necessity of voiding the bowel and bladder remains critically under-investigated. Subsequently, physicians and caregivers are rarely presented with consistent, evidence-based strategies to successfully address the consequences of dysregulated voiding reflexes. Neurogenic bowel is commonly believed to result from the interruption of the supraspinal control of the spinal autonomic circuits regulating the colon. In this mini-review, we discuss the clinical challenges presented by neurogenic bowel and emerging pre-clinical evidence that is revealing that SCI also initiates functional remodeling of the colonic wall concurrent with a decrease in local enteric neurons. Since the enteric input to the colonic smooth muscle is the final common pathway for functional contractions of the colon, changes to the neuromuscular interface must first be understood in order to maximize the efficacy of therapeutic interventions targeting colonic dysfunction following SCI.

Partners in Crime: NGF and BDNF in Visceral Dysfunction

Neurotrophins (NTs), particularly Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF), have attracted increasing attention in the context of visceral function for some years. Here, we examined the current literature and presented a thorough review of the subject. After initial studies linking of NGF to cystitis, it is now well-established that this neurotrophin (NT) is a key modulator of bladder pathologies, including Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) and Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS. NGF is upregulated in bladder tissue and its blockade results in major improvements on urodynamic parameters and pain. Further studies expanded showed that NGF is also an intervenient in other visceral dysfunctions such as endometriosis and Irritable Bowel Syndrome (IBS). More recently, BDNF was also shown to play an important role in the same visceral dysfunctions, suggesting that both NTs are determinant factors in visceral pathophysiological mechanisms. Manipulation of NGF and BDNF improves visceral function and reduce pain, suggesting that clinical modulation of these NTs may be important; however, much is still to be investigated before this step is taken. Another active area of research is centered on urinary NGF and BDNF. Several studies show that both NTs can be found in the urine of patients with visceral dysfunction in much higher concentration than in healthy individuals, suggesting that they could be used as potential biomarkers. However, there are still technical difficulties to be overcome, including the lack of a large multicentre placebo-controlled studies to prove the relevance of urinary NTs as clinical biomarkers.