A review of sacral nerve stimulation parameters used in the treatment of faecal incontinence

Stimulation of the tibial nerve-a randomised trial for urinary problems associated with Parkinson's-the STARTUP trial

BACKGROUND

non-motor symptoms such as bladder dysfunction are common (80%) in people with Parkinson's increasing the risk for falls with a negative impact on health-related costs and quality of life.We undertook STARTUP to evaluate the clinical and cost-effectiveness of using an adhesive electrode to stimulate the transcutaneous tibial nerve stimulation (TTNS) to treat bladder dysfunction in people with Parkinson's disease (PD).Study design, materials and methods: STARTUP was a parallel two-arm, multi-centre, pragmatic, double-blind, randomised controlled trial. Each participant attended one clinic visit to complete consent, be randomised using a computer-generated system and to be shown how to use the device.The trial had two co-primary outcome measures: International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form and the International Prostate Symptom Score (IPSS). These were completed at baseline, 6 and 12 weeks. A bladder frequency chart and resource questionnaire were also completed.

RESULTS

two hundred forty two participants were randomised. About 59% of participants were male, the mean age was 69 years and mean time since diagnosis was 6 years. Questionnaire return rate was between 79 and 90%.There was a statistically significantly lower score in the active group at 6 weeks in the IPSS questionnaire (mean difference (Standard deviation, SD) 12.5 (6.5) vs 10.9 (5.5), effect size -1.49, 95% CI -2.72, -0.25). There was no statistically significant change in any other outcome.

CONCLUSION

TTNS was demonstrated to be safe with a high level of compliance. There was a significant change in one of the co-primary outcome measures at the end of the treatment period (i.e. 6 weeks), which could indicate a benefit. Further fully powered RCTs are required to determine effective treatments.

Interstitial cells of Cajal and human colon motility in health and disease

Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.

Effects of sEA on Slow Transit Constipation through the Microbiota-Gut-Brain Axis in Rats

To investigate the effect of sacral electroacupuncture (sEA) on the microbiota-gut-brain axis in the treatment of slow transit constipation, this study established a drug-induced model of slow transit constipation in rats and carried out sEA at the Baliao acupoints (BL31-BL34). On the 14th day of the therapeutic period (24 h fecal pellets), the aquaporin 3 (AQP3), 5-hydroxytryptamine (5-HT), and substance P (SP) transcripts from the distal colon and hypothalamus were analyzed. 16S rDNA has been widely used to analyze the diversity of the microbial communities. Therefore, in the present study, changes in the intestinal microbiota were analyzed by 16S rDNA gene sequencing. The results showed that sEA significantly increased the number of fecal pellets and the water content in the feces and reduced the reabsorption of intestinal water in 24 h. sEA also upregulated the level of SP mRNA expression in the distal colon and the hypothalamus, but downregulated the level of 5-HT mRNA expression in the distal colon. Moreover, sEA improved the Bacteroidetes to Firmicutes (B/F) ratio, which is beneficial to the general structure of the intestinal microflora. Our findings suggested that the microbiota-gut-brain axis constitutes a crucial pathological basis in the development of slow transit constipation. sEA improved the slow transit constipation by regulating the balance of the microbiota-gut-brain axis.

Transcutaneous tibial nerve stimulation for the treatment of bladder storage symptoms in people with multiple sclerosis: Protocol of a single-arm feasibility study

Background: Neurogenic lower urinary tract dysfunction (NLUTD) is common among people with multiple sclerosis (MS) with a pooled prevalence of 68.41% using self-report measures and 63.95% using urodynamic studies. Transcutaneous tibial nerve stimulation (TTNS) is a non-invasive option to manage bladder storage symptoms; however, the potential efficacy of TTNS among people with MS is based on a small number of studies with the absence of high-quality evidence relating to efficacy, and lack of clarity of the optimal electrical stimulation parameters and frequency, duration and number of treatment sessions. This study aims to assess whether TTNS is feasible and acceptable as a treatment for bladder storage symptoms in people with MS. Methods: We will use a single-arm experimental study to explore the feasibility and acceptability of TTNS in the treatment of bladder storage symptoms in MS. The CONSORT extension for pilot and feasibility studies will be followed to standardise the conduct and reporting of the study. The recruitment plan is twofold: 1) Open recruitment for people with MS through MS Ireland's communication channels; 2) recruitment from a convenience sample of people with MS who have previously participated in a qualitative interview study of urinary symptoms. We will assess recruitment/retention rates, the urinary symptoms changes and the effect on quality of life pre and post intervention using ICIQ-OAB, 3-day bladder diary, King's Health Questionnaire and collect self-reported data on adherence and adverse events. Acceptability of using TTNS will be evaluated at the end of intervention. This study has been reviewed and approved by the Education and Health Science's Faculty Research Ethics Committee, University of Limerick [2020_06_07_EHS].  Conclusion: It is anticipated that assessing the feasibility and acceptability of TTNS for storage bladder symptoms in MS will inform the development of a definitive randomised trial. Trial registration: ClinicalTrials.gov NCT04528784 27/08/2020.

Programming Algorithms for Sacral Neuromodulation: Clinical Practice and Evidence-Recommendations for Day-to-Day Practice

Background

In sacral neuromodulation (SNM), stimulation programming plays a key role to achieve success of the therapy. However to date, little attention has been given to the best ways to set and optimize SNM programming during the test and chronic stimulation phases of the procedure.

Objective

Standardize and make SNM programming easier and more efficient for the several conditions for which SNM is proposed.

Methods

Systematic literature review and collective clinical experience report.

Results

The basic principles of SNM programming are described. It covers choice of electrode configuration, stimulation amplitude, pulse frequency and pulse widths, while use of cycling is also briefly discussed. Step‐by‐step practical flow charts developed by a group of 13 European experts are presented.

Conclusions

Programming of SNM therapy is not complex. There are few programming settings that seem beneficial or significantly impact patient outcomes. Only four basic electrode configurations could be identified according to four different options to define the cathode. In a majority of patients, the proposed stimulation parameters will allow a satisfactory improvement for long periods of time. A regular follow‐up is, however, necessary to assess and eventually optimize results, as well as to reassure patients.

An intravital window to image the colon in real time

Intravital microscopy is a powerful technique to observe dynamic processes with single-cell resolution in live animals. No intravital window has been developed for imaging the colon due to its anatomic location and motility, although the colon is a key organ where the majority of microbiota reside and common diseases such as inflammatory bowel disease, functional gastrointestinal disorders, and colon cancer occur. Here we describe an intravital murine colonic window with a stabilizing ferromagnetic scaffold for chronic imaging, minimizing motion artifacts while maximizing long-term survival by preventing colonic obstruction. Using this setup, we image fluorescently-labeled stem cells, bacteria, and immune cells in live animal colons. Furthermore, we image nerve activity via calcium imaging in real time to demonstrate that electrical sacral nerve stimulation can activate colonic enteric neurons. The simple implantable apparatus enables visualization of live processes in the colon, which will open the window to a broad range of studies.

Performing intravital imaging of the colon in mouse models is challenging due to the colon’s anatomic location and motility. Here, the authors develop a murine colonic window for intravital chronic imaging that maximises long-term animal survival and minimises motion artefacts.

The "rectosigmoid brake": Review of an emerging neuromodulation target for colorectal functional disorders

The regulation of gastrointestinal motility encompasses several overlapping mechanisms including highly regulated and coordinated neurohormonal circuits. Various feedback mechanisms or "brakes" have been proposed. While duodenal, jejunal, and ileal brakes are well described, a putative distal colonic brake is less well defined. Despite the high prevalence of colonic motility disorders, there is little knowledge of colonic motility owing to difficulties with organ access and technical difficulties in recording detailed motor patterns along its entire length. The motility of the colon is not under voluntary control. A wide range of motor patterns is seen, with long intervals of intestinal quiescence between them. In addition, the use of traditional manometric catheters to record contractile activity of the colon has been limited by the low number of widely spaced sensors, which has resulted in the misinterpretation of colonic motor patterns. The recent advent of high-resolution (HR) manometry is revolutionising the understanding of gastrointestinal motor patterns. It has now been observed that the most common motor patterns in the colon are repetitive two to six cycles per minute (cpm) propagating events in the distal colon. These motor patterns are prominent soon after a meal, originate most frequently in the rectosigmoid region, and travel in the retrograde direction. The distal prominence and the origin of these motor patterns raise the possibility of them serving as a braking mechanism, or the "rectosigmoid brake," to limit rectal filling. This review aims to describe what is known about the "rectosigmoid brake," including its physiological and clinical significance and potential therapeutic applications.