Cortical Mechanisms of Human Pelvic Floor Muscle Synergies

The human pelvic floor is an anatomically, functionally, and morphologically complex region that is associated with many disorders such as chronic prostatitis/pelvic pain syndrome (CPPS), chronic low back pain, and urinary incontinence. The purpose of this dissertation was to explore the cortical mechanisms that underlie human pelvic floor muscle synergies. Our first original experiment involved the study of 20 healthy male controls who were instructed to perform a variety of muscle tasks presumed to be associated with pelvic floor muscle synergies. Surface electromyography (EMG) method was used to detect timing onsets, as well as activation patterns of the pelvic floor, gluteus maximus, and first dorsal interosseous muscles. Functional magnetic resonance imaging (fMRI) was used to measure blood oxygenation density levels (BOLD) in the brain while subjects performed various prime mover tasks. Our second original experiment involved another set of 10 healthy male subjects who were trained to perform a complex synergy breaking/decoupling task that was confirmed with EMG. They repeated the coupling motor task (gluteal activation) as well as the more complex motor decoupling task while being scanned with fMRI, so that BOLD signals could be compared. The first experiment revealed evidence of cortically facilitated synergy of the pelvic floor muscles and the second experiment revealed that complex motor tasks such as the breaking of a cortically facilitated muscle synergy involves BOLD signals in the brain known to be involved with interoception

Ultrasound of the female urethra

Background: Many theories have been put forward to explain the urinary continence mechanism. Though they seem logical, there is insufficient evidence to support them. Ultrasound has been implemented by researchers to investigate these theories. There is considerable difference in their methodologies and their conclusions. Most of the research on urethral ultrasound is related to stress incontinence; there is a lack of studies on other urodynamic diagnoses. Aim: To compare the measurements of the female urethra by transperineal ultrasound in women with different urodynamic diagnoses and different vaginal parities. Methodology: 150 women had urodynamic studies and 2 and 3 dimensional transperineal ultrasound. They were divided into 4 groups according to their urodynamic diagnosis as nondiagnostic urodynamics(NU), pure detrusor overactivity(PureDO), pure urodynamic stress incontinence(PureUSI) and mixed urinary incontinence(MUI) and also according to their vaginal parity. New methods of measuring urethral position, bladder neck position and urethral dimension are developed and used for measurement. Multiple regression analysis was performed using a model of urethral sphincter volume(USV), bladder neck position(BNP) and pubourethral distance. Key findings: USV was smallest in PureUSI and largest in PureDO groups. BNP at rest was lower in all incontinent groups than NU. MUI group had normal sphincter size but lower BNP. There was no difference in the bladder neck mobility or urethral mobility. Urethral compression was evident in all groups. The statistical model correctly classified 68.2% women with urodynamic stress incontinence and 69.8% women with detrusor overactivity. The urethral sphincter was smaller in women who had a vaginal delivery but there was no difference in the sphincter size of primiparous and multiparous women. Conclusion: Urethral sphincter volume and bladder neck position are the most differentiating factors for the types of urinary incontinence. Subsequent vaginal delivery in primiparous women may not increase their risk of having urinary incontinence.Open Acces

Non-invasive urinary bladder volume estimation with artefact-suppressed bio-impedance measurements

Urine output is a vital parameter to gauge kidney health. Current monitoring methods include manually written records, invasive urinary catheterization or ultrasound measurements performed by highly skilled personnel. Catheterization bears high risks of infection while intermittent ultrasound measures and manual recording are time consuming and might miss early signs of kidney malfunction. Bioimpedance (BI) measurements may serve as a non-invasive alternative for measuring urine volume in vivo. However, limited robustness have prevented its clinical translation. Here, a deep learning-based algorithm is presented that processes the local BI of the lower abdomen and suppresses artefacts to measure the bladder volume quantitatively, non-invasively and without the continuous need for additional personnel. A tetrapolar BI wearable system called ANUVIS was used to collect continuous bladder volume data from three healthy subjects to demonstrate feasibility of operation, while clinical gold standards of urodynamic (n=6) and uroflowmetry tests (n=8) provided the ground truth. Optimized location for electrode placement and a model for the change in BI with changing bladder volume is deduced. The average error for full bladder volume estimation and for residual volume estimation was -29 +/-87.6 ml, thus, comparable to commercial portable ultrasound devices (Bland Altman analysis showed a bias of -5.2 ml with LoA between 119.7 ml to -130.1 ml), while providing the additional benefit of hands-free, non-invasive, and continuous bladder volume estimation. The combination of the wearable BI sensor node and the presented algorithm provides an attractive alternative to current standard of care with potential benefits in providing insights into kidney function

Applications of EMG in Clinical and Sports Medicine

This second of two volumes on EMG (Electromyography) covers a wide range of clinical applications, as a complement to the methods discussed in volume 1. Topics range from gait and vibration analysis, through posture and falls prevention, to biofeedback in the treatment of neurologic swallowing impairment. The volume includes sections on back care, sports and performance medicine, gynecology/urology and orofacial function. Authors describe the procedures for their experimental studies with detailed and clear illustrations and references to the literature. The limitations of SEMG measures and methods for careful analysis are discussed. This broad compilation of articles discussing the use of EMG in both clinical and research applications demonstrates the utility of the method as a tool in a wide variety of disciplines and clinical fields

An investigation of the mechanism of sacral nerve stimulation in restoring voiding function.

Sacral nerve stimulation, or neuromodulation, has been shown to restore voiding in women with a specific type of urinary retention that is attributed to urethral sphincter overactivity. The therapy has gained popularity in this and other voiding dysfunctions, but its mechanism of action remains unexplained. This thesis explores the effects of neuromodulation on women with urinary retention. It incorporates a urodynamic study of the effect of neuromodulation on bladder and urethral (peripheral) function, a functional brain imaging PET (Positron Emission Tomography) study of cerebral (central) effects, and a review of the long-term efficacy of the technique. The urodynamics (including urethral pressure profilometry, cystometry, and sphincter electromyography) showed evidence of persistent urethral overactivity despite successful restoration of micturition. Together with the cystometric findings, this suggests that neuromodulation may facilitate voiding in this group by increasing detrusor contractility rather than by urethral relaxation. Review of the sacral nerve implants performed at this centre over several years reveals that approximately 75% continue to void at up to 5 years after surgery, while considering reasons for the loss of efficacy in other patients. The cerebral perception of bladder fullness was examined using PET scanning in a group of healthy female controls as well as women with retention treated by neuromodulation. The findings show that the brainstem activity which is present in healthy controls is not seen in retention patients until the neuromodulation is activated. The discussion addresses the respective roles of brainstem and cortical brain regions in the control of voiding function, and whether neuromodulation may 'normalize' cerebral activity. In conclusion, this thesis provides evidence, for the first time, of changes in brain activity following sacral neuromodulation in urinary retention, confirming that its effects may well be mediated by afferent innervation

Integration of novel diagnostic techniques and in-depth characterisation of anorectal (dys)function in studies of healthy volunteers and patients with faecal incontinence

Introduction Large overlap in the range of values seen in health and disease limit the clinical utility of investigations which describe pathophysiological findings in faecal incontinence (FI). Aims The aims of this thesis were to: 1. investigate the prevalence of major disorders of anal motor and rectal sensory function in FI; 2. better describe stress FI; 3. expand knowledge of normal ranges and develop novel metrics to evaluate anorectal function using both contemporary and emerging diagnostic tests (Rapid Barostat Bag [RBB] pump and the functional lumen imaging probe [EndoFLIP®]); 4. develop understanding of (the role of) parity on anorectal function in health and FI; 5. investigate the interaction of continence mechanisms in healthy individuals. Methods Research methods used in this thesis include systematic review and meta-analysis, retrospective case-control and cohort studies, and a prospective study of anorectal function in health using contemporary and new technologies. Results Anal hypocontractility is the most common pathophysiological finding in FI, but rectal sensory dysfunction remains important, especially in men. Further, assessment of the cough response and amplitude of anal slow waves revealed subtle anal motor dysfunction not appreciated by traditional metrics. Stress FI is poorly researched but common, and appears to represent a more severe FI phenotype. For the first time, normal ranges for rectal compliance, capacity and sensation were generated using the RBB, and distensibility of the anal canal using EndoFLIP®. Prospective studies in health demonstrated limited impact of parity on individual metrics. Conclusion While routine clinical tests of anorectal function are useful for evaluating FI, identification of characteristics or metrics associated with progressive decline in function may prove useful for detecting individuals at risk of FI. Research in healthy populations remains relevant to maintain pace with advancing technology; the concept of normality is still an important part of clinical care

Fecal Incontinence

Fecal incontinence is a common and disabling condition that unfortunately remains an “orphan” in terms of medical research and effective therapies. This book provides a brief review of the pathophysiology of fecal incontinence with specific focus on women and children. Authorship is drawn internationally, with a strong surgical input. Contributions from the authors provide critical reviews of the evaluation of function, with illustrations of a range of surgical interventions which might be applied should medical therapies fail

Système implantable pour la mesure de la pression vésicale et analyse prédictive de la miction

L’incontinence et les autres pathologies liées aux troubles du système urinaire inférieur peuvent causer de très profonds traumas psychologiques, en plus de limiter l’autonomie des patients. En effet, ce sujet, toujours tabou, est très difficile à évoquer. Ainsi, de nombreuses personnes en souffrent d’autant plus qu’elles n’osent pas en parler à leurs proches ou leurs médecins. Pourtant, des solutions existent, notamment des sphincters artificiels qui permettent d’éviter les fuites involontaires d’urine, en particulier chez les paraplégiques et les tétraplégiques. Cependant, ces solutions, bien qu’efficaces, ne sont pas optimales. N’ayant pas la sensation d’envie, les patients ne peuvent savoir lorsque leur vessie est pleine. Ceci limite donc grandement leur autonomie. En effet, une vessie trop pleine (volume supérieur à 600 mL) peut mener à de graves infections et même menacer la vie du patient. La mesure du volume de la vessie est possible par échographie et peut se substituer au sondage pour évaluer la rétention urinaire et rechercher des résidus post-mictionnels par exemple avec le Bladder-scan BVI-3000®. Cette méthode, non-invasive, ne permet cependant pas de prédire la miction. Elle n’est, de plus, pas vraiment portable. Ainsi, plutôt que de mesurer le volume de la vessie, la mesure de la pression du détrusor – muscle recouvrant les parois de la vessie – est beaucoup plus intéressante et utile. Cette dernière se calcule par la soustraction de la pression abdominale à la pression vésicale. La mesure de cette pression peut être faite par un implant, ce qui est invasif, mais limite les risques d’infection tout en maximisant le confort du patient. Pour cette maîtrise, le travail effectué s’appuie sur la réalisation, le développement et le prototypage d’un tel implant dans un souci de biocompatibilité et d’acceptation chez l’être humain. Par ailleurs, et faisant suite au développement de cet implant, un travail sur la prédiction de la miction chez le rat a été réalisé. Dans cette étude, l’utilisation d’algorithmes d’apprentissages solides nécessitant une faible puissance de calcul a été favorisée. À terme, cela permettra une intégration facile dans des implants vésicaux. La pertinence des résultats permet d’envisager des études plus poussées et complètes, notamment en augmentant la taille des bases de données utilisées. Pour cela, une génération de courbes temporelles de pression de la vessie par modélisation informatique a été tentée, qui n’est malheureusement pas encore concluante.----------ABSTRACT Urinary incontinence (UI) and the other lower urinary tracts symptoms are both limiting convalescents’ autonomy and psychologic well-being. Indeed, this subject is still taboo in most part of the world. For people suffering from UI, it is very difficult to bring the subject with their relatives or their doctors. However, solutions exist, for instance, artificial sphincters allow to avoid involuntary leakage of urine in particularly for tetraplegic or paraplegic. Nevertheless, these solutions are efficient, but the patients cannot know whether their bladder is full or empty. Patients’ autonomy is then still low – they cannot be far from a bathroom for more than two hours. Though, having a more than 600 mL bladder volume can lead to serious infections and even threaten the patient’s life. Ultrasounds, for instance the Bladder-scan BVI-3000® device, allow the measurement of the bladder volume. It can be used instead of catheter to measure the volume of retained urine or post-urination residue. However, this non-invasive method cannot help to predict micturition. Moreover, this device cannot be easily carried out. Therefore, the measurement of the detrusor pressure – the muscle of the bladder wall – is far more useful. This pressure is computed by subtracting the abdominal pressure to the vesical pressure. The measurement of the pressure is done by invasive implants, which has some obvious drawbacks, but avoid infection risks and maximize the patient comfort. The presented master work relies on the realisation, the development and the prototyping of such an implant in a care of human biocompatibility. Besides, following the implant development, the main work consists of finding a way to predict voiding. It was executed with data on rats having normal and overactive bladder conditions. The prediction was done thanks to machine learning algorithm, which minimize power consumption in order to allow an integration of this algorithm in an embedded device. Our positive results confirm the possibility of predicting voiding and allow to consider new studies with larger set of data. Generating data with the help of an informatic modeling was tried. Unfortunately, our results still present some flaws in terms of similarity with a typical bladder pressure curve in rats

Refining and improving the assessment and treatment of faecal incontinence

Faecal incontinence (FI) is a common symptom. There are a variety of invasive treatments available, however, the benign nature of this problem and the varying degrees of severity, mean that conservative management is usually pursued first. The aims of this thesis were to investigate: the current practice of continence advisors who deliver conservative management in the community in the UK; assess and evaluate a new portable manometric device (THD® Anopress); investigate a new first line treatment for FI (Renew™) and compare this to another well-established non-invasive treatment (PTNS); report the long-term effectiveness of SNM; and, describe the short term outcome of the newer Sphinkeeper procedure. Results of this thesis lead to the conclusion that continence advisors are an important part of the management of FI in the community and that while they are able to utilise many of the current treatments, there is room for improvement. Normal range values for the new portable manometric device Anopress have been reported for the first time. It has been demonstrated that Anopress device appears able to detect anal sphincter dysfunction in those with symptomatic FI, and most importantly, Anopress measurements correlate strongly with water-perfused manometry. Results reported by this thesis also demonstrated that the Renew device is safe, well tolerated and an effective non-invasive treatment for passive FI. The randomized controlled trial suggests that both the Renew device and PTNS are effective treatments for FI, although Renew inserts may be more effective than PTNS. SNS was confirmed as an effective treatment for FI even in the long term with a consistent improvement of validated FI scores for approximately 60% of all patients reviewed at 11 years post implantation. Sphinkeeper was also demonstrated to be a safe and feasible alternative procedure for FI.Open Acces