Real-life after sacral nerve modulation implantation: Rate, reasons, and risk factors for mid-term follow-up discontinuation.

OBJECTIVES: To evaluate follow-up after implantation of a sacral nerve modulation implantable pulse generator (IPG) and to investigate the reasons and risk factors for follow-up discontinuation. MATERIALS AND METHODS: All patients who underwent an IPG implantation to treat lower urinary tract symptoms between 2014-2019 within 6 hospital centers located in the district of "Hauts-de-France" (France) were systematically called during the year 2020 for a standardized (tele)consultation. Patients were divided into 3 distinct profiles according to the regularity of their 5-year postoperative follow-up: "Regular follow-up", "Irregular follow-up" and "Lost to follow-up". The primary outcome was the change in the annual proportion of the 3 follow-up profiles over the 5 years following IPG implantation. As secondary outcomes we described the reasons reported for follow-up discontinuation and looked for risk factors associated with. RESULTS: Overall, 259 patients were included. At the time of data collection, after a mean follow-up of 28.4 (± 19.8) months, 139 patients (53.7%) had a "Regular follow-up", 54 (20.8%) had an "Irregular follow-up" and 66 (25.5%) were "Lost to follow-up". The proportion of patients with a "Regular follow-up" decreased year by year, representing only 46.2% of patients at five-years. 175 patients (67.6%) underwent a standardized (tele)consultation. In multivariate analysis, only "lack of knowledge of the follow-up protocol" was statistically associated with follow-up discontinuation (OR=5.16; 95% CI [2.12-13.57]). CONCLUSION: The proportion of patients followed up after IPG implantation decreased steadily over the years, often related to a lack of therapeutic education.

Peak retrograde flow a potential objective management tool to identify young adults with varicocele 'at risk' for a high sperm DNA fragmentation.

INTRODUCTION: Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who would benefit most from surgery. Since conventional semen parameters, have been limited in their ability to evaluate the negative effects of varicocele on fertility, specialized laboratory tests have emerged. OBJECTIVE: To identify clinical and ultrasound parameters (including PRF) which would negatively influence standard and functional semen variables in young adults with a varicocele. DESIGN: Prospective, cross-sectional observational study. SETTING: Antwerp University Hospital, Belgium. PATIENT(S): Young volunteers between 16 and 26 years, Tanner 5, were recruited. INTERVENTION(S): Every participant had a scrotal ultrasound to calculate testicular volumes. If a varicocele was present, the grade, vein diameter, peak retrograde flow (PRF) in supine position and spontaneous reflux in standing position were measured. All participants provided a semen sample. Standard semen parameters were analyzed and sperm DNA fragmentation. MAIN OUTCOME MEASURE(S): Of all clinical and ultrasound parameters tested, PRF was an objective tool identifying young adults with a varicocele. PRF was highlighted by the prevalence of SDF, both in the total and vital fractions of the spermatozoa, providing opportunities to manage such 'at-risk' adolescents/young adults. RESULT(S): Total SDF was significantly increased in grade 3 varicocele compared to grade 1 and 2 but no significant difference with vital SDF or standard descriptive semen parameters was seen. Total and vital SDF on the other hand were significantly increased when PRF was above 38.4 cm/s. Standard semen analysis showed no difference with PRF as an independent predictor. Testicular atrophy index, varicocele vein diameter and spontaneous reflux revealed no significant differences in both the descriptive and functional semen variables. DISCUSSION: Descriptive semen parameters showed no significant difference between the non-varicocele controls and the varicocele group with low and high PRF. Increased PRF negatively influenced sperm quality via increased DNA fragmentation both in the total as in the vital fractions of the semen. CONCLUSION(S): Of all clinical and ultrasound parameters tested, PRF was an objective non-invasive tool to identify varicocele patients at risk for a high SDF.

[Neuromodulation of lower urinary tract dysfunction]. / Neuromodulation bei Harnblasenfunktionsstörungen.

Neuromodulative procedures such as transcutaneous electrical nerve stimulation (TENS), transcutaneous/percutaneous tibial nerve stimulation (TTNS/PTNS), and sacral neuromodulation (SNM) are promising second-line treatments for refractory lower urinary tract dysfunction. Using these therapies, both storage and voiding disorders but also bowel dysfunction might be successfully treated. Although the mechanism of action of neuromodulation is not well understood, it seems to involve modulation of spinal cord reflexes and brain networks by peripheral afferents (genital/rectal, tibial and sacral afferents in the case of TENS, TTNS/PTNS, and SNM, respectively). Neuromodulative procedures might also be highly effective in the most desperate situations and further relevant developments are expected so that these innovative techniques will most likely become even more important in urology.

Distribution and sub-types of afferent fibre in the mouse urinary bladder.

AIM: Increased afferent fibre activity contributes to pathological conditions such as the overactive bladder syndrome. Nerve fibres running near the urothelium are considered to be afferent as no efferent system has yet been described. The aim of this study was to identify sub-types of afferent nerve fibres in the mouse bladder wall based on morphological criteria and analyse regional differences. MATERIALS AND METHODS: 27 bladders of six month old C57BL/6 mice were removed and tissues were processed for immunohistochemistry. Cryostat sections were cut and stained for Protein Gene Product 9.5 (PGP), calcitonin gene related polypeptide (CGRP), neurofilament (NF), vesicular acetylcholine transporter (VAChT) and neuronal nitric oxide synthase (nNOS). RESULTS: In the sub-urothelium, different types of afferent nerve fibre were found, i.e. immunoreactive (IR) to; CGRP, NF, VAChT, and/or nNOS. At the bladder base, the sub-urothelium was more densely innervated by CGRP-IR and VAChT-IR nerve fibres, then at the lateral wall. NF- and nNOS nerves were sparsely distributed in the sub-urothelium throughout the bladder. At the lateral wall the inner muscle is densely innervated by CGRP-IR nerve fibres. NF, VAChT and nNOS nerves were evenly distributed in the different muscle layers throughout the bladder. Nerve fibre terminals expressing CGRP and NF were found within the extra-mural ganglia at the bladder base. CONCLUSIONS: Different types of afferent nerve fibres were identified in the sub-urothelium of the mouse bladder. At the bladder base the sub-urothelium is more densely innervated than the lateral wall by CGRP-IR and VAChT-IR afferent nerve fibres. CGRP and NF afferent nerve fibres in the muscle layer probably relay afferent input to external ganglia located near the bladder base. The identification of different afferent nerves in the sub-urothelium suggests a functional heterogeneity of the afferent nerve fibres in the urinary bladder.

Changes in voiding behavior in a mouse model of Alzheimer's disease.

Besides cognitive decline and behavioral alteration, urinary incontinence often occurs in patients suffering from Alzheimer's disease (AD). To determine whether the transgenic mouse model of AD, APP/PS1 (APP(SL)/PS1(M146L)) mouse, shows alteration of the urinary bladder function and anxiety, as for patients with AD, we examined the urinary marking behavior in relation to affective behavior. At 18 months of age voiding behavior of APP/PS1 and wild type (WT) mice was assessed by using a modified filter paper assay in combination with video tracing, with the cage divided into a center and corner zones. Anxiety-related behavior and locomotion were respectively tested in an elevated zero maze (EZM) and an open field (OF). The APP/PS1 mice urinated more in the center zone than the WT mice. The total volume of markings was significantly lower in the APP/PS1 mice. In both groups, the average volume of a marking in the corner zone was larger than in the center zone. In the EZM, the APP/PS1 mice spent less time in the open arms of the arena, considered as anxiogenic zones, than the WT mice. During the OF task, the APP/PS1 mice covered a longer distance than the WT mice. These findings show that the APP/PS1 mice have a different voiding behavior compared to the WT mice, i.e., urinating with small volumes and voiding in the center of the cage, and suggest that increased locomotor activity and anxiety-related behaviors are factors in the change in voiding pattern in the APP/PS1 mouse.

The effect of non-surgical weight loss interventions on urinary incontinence in overweight women: a systematic review and meta-analysis.

Although the aetiology of urinary incontinence can be multifactorial, in some cases weight loss could be considered as a part of the therapeutic approach for urinary incontinence in people who are overweight. The objective of this study was to review and meta-analyse the effect of non-surgical weight loss interventions on urinary incontinence in overweight women. Web of Science, PubMed, Pedro, SPORTDiscus and Cochrane were systematically searched for clinical trials that met the a priori set criteria. Data of women who participated in non-surgical weight loss interventions (diet, exercise, medication or a combination) were included in the meta-analysis. After removing duplicates, 62 articles remained for screening on title, abstract and full text. Six articles (totalling 2,352 subjects in the intervention groups) were included for meta-analysis. The mean change in urinary incontinence (reported as frequency or quantity, depending on the study) after a non-surgical weight loss intervention, expressed as standardized effect size and corrected for small sample sizes (Hedges' g), was -0.30 (95%CI = -0.47 to -0.12). This systematic review and meta-analysis shows evidence that a non-surgical weight loss intervention has the potential to improve urinary incontinence and should be considered part of standard practice in the management of urinary incontinence in overweight women.

Do patients with OAB experience bladder sensations in the same way as healthy volunteers? A focus group investigation.

AIMS: To describe the terminology and pattern of bladder sensations experienced during non-invasive rapid bladder filling in a controlled setting in patients with OAB and to compare these results with a previous study conducted in healthy volunteers. METHODS: Three groups of patients with OAB, in total 10 patients, participated in three consecutive focus group sessions. Before each session a strict water loading protocol was given. During the first two sessions, participants described how they experienced their bladder sensations in daily life and during a non-invasive bladder filling with constant focus on their bladder. The third session focused on verifying the interpretation of the data gathered and describing the pattern of sensations. RESULTS: Patients describe their bladder sensations as a pressure or a tingling sensation and the pattern can be described by terms ranging from no sensation to an absolute need to void. The absolute need to void may develop suddenly or more slowly progressive. The mean development of bladder sensation is significantly different between patients and healthy volunteers as well as their average diuresis. CONCLUSIONS: Patients with OAB describe their bladder sensations as a pressure or a tingling sensation. There appear to be two types of urgency: a sudden absolute need to void and a slowly developing absolute need to void. Furthermore bladder sensation develops significantly different in volunteers than in OAB patients.

How should bladder sensation be measured? ICI-RS 2011.

AIMS: Disturbed bladder sensations, or in broader terms, sensory dysfunctions are increasingly recognized as key elements in the origin and manifestation of symptom syndromes of urinary dysfunction. Adequate assessment of bladder sensation is crucial to improve our understanding of the pathophysiology and treatment of urinary dysfunction. This manuscript summarizes the discussions of a think tank on "How to measure bladder sensation" held at the ICI-RS meeting in 2011. METHODS: Based upon literature reviews on bladder sensation presented at the think tank in the ICI-RS meeting, discussions evolved which were summarized in the ICI-RS report. Different physicians/researchers further elaborated on this report, which is presented in this manuscript. RESULTS: Bladder sensations are not merely the result of bladder distension. Other factors inside the bladder or bladder wall: central processing and/or cognitive manipulation may play an important role. Current methods to measure sensations such as urodynamics, voiding diaries, forced diuresis, electrical stimulation and brain imaging are likely sub-optimal as they only consider part of these factors in isolation. CONCLUSIONS: Different methods to measure bladder sensations have been described and are used in clinical practice. Current methods only address part of the parameters responsible for the generation and perception of urinary sensations. Further focused research is required, and several recommendations are provided.

Development and psychometric evaluation of a dutch questionnaire for the assessment of anorectal and lower urinary tract symptoms.

BACKGROUND AND STUDY AIMS: Epidemiological studies have shown a frequent coexistence of symptoms and diseases affecting the anorectum and lower urinary tract. To further investigate combined symptoms and pathology of both pelvic viscera we developed a self-reported questionnaire, in Dutch, which extensively evaluates habits, complaints and symptoms of both viscera. We describe the construction and the psychometric properties of this questionnaire. PATIENTS AND METHODS: This prospective study was conducted in 56 patients with anorectal symptoms, 41 patients with lower urinary tract symptoms and in a control group of 91 people. The following psychometric properties of the questionnaire were evaluated: content validity, construct validity, criterion validity, test-retest reliability and internal consistency. RESULTS: The questionnaire covered all important domains, was well interpreted and showed good acceptability (content validity). The questionnaire clearly differentiated the patient populations (construct validity). The criterion validity of the questionnaire was excellent. The test-retest reliability of the questionnaire was acceptable in all three the study populations (overall median kappa: 0.64; Inter Quartile Range: 0.56-0.75; mean agreement: 88%). The internal consistency of both anorectal and lower urinary tract symptom questions was high (Crohnbach's alpha of 0.78 and 0.80 respectively). CONCLUSIONS: This questionnaire is a valid and reliable instrument for the assessment of anorectal and lower urinary tract symptoms. It can provide further insights into the epidemiology of concomitant bowel and bladder disorders and, accordingly, can contribute to a more efficient diagnostic and therapeutic approach in patients with such disorders.

Sacral neuromodulation as a treatment for chronic pelvic pain.

PURPOSE: Chronic pelvic pain syndrome is a debilitating disease which often has a major impact on quality of life. A significant number of patients do not respond to conservative treatment and often no good alternative can be offered except radical surgery. Sacral neuromodulation is a well established therapy for patients with lower urinary tract dysfunction. This therapy has also been suggested to be useful in the treatment of chronic pelvic pain. Although currently no Food and Drug Administration approval exists for this indication, several studies have demonstrated promising results. We provide an overview of the published literature on sacral neuromodulation as a treatment for chronic pelvic pain. MATERIALS AND METHODS: A PubMed® search was performed to identify articles in English from 1990 to February 2010 reporting treatment of pelvic pain with sacral neuromodulation. In addition, the current definitions of pelvic pain syndromes and the mechanisms of action are discussed. RESULTS: A total of 12 relevant articles were identified. Of these articles 10 mainly addressed the efficacy of sacral neuromodulation in patients with interstitial cystitis/bladder pain. The percentage of patients who responded to test stimulation was reported between 51% and 77%. Of the 10 articles 7 reported treatment outcome after implantation. The duration of followup ranged between 5 and 87 months. The mean reduction in pain scores was reported between 40% and 72%. The reoperation rate ranged between 27% and 50% after long-term followup. Two articles included patients with miscellaneous urogenital pain syndromes. The success rates after implantation ranged from 60% to 77% with followup ranging between 19 and 36 months. CONCLUSIONS: Currently there is insufficient evidence to determine the role of sacral neuromodulation in the treatment of chronic pelvic pain. Larger prospective trials with long-term evaluation are required to determine the ultimate efficacy of this treatment.

Bladder compliance what does it represent: can we measure it, and is it clinically relevant?

AIMS: To report the conclusion of the Think Thank 8 on Compliance Discussions during the second ICI-RS meeting in 2010. METHODS: During a 3-day meeting a group of specialists discussed bladder compliance, what it represents, how it can be measured and if it is clinically relevant. RESULTS: Bladder compliance is the result of a mathematical calculation of the volume required for a unit rise of pressure measured during a cystometric filling. It gives an indication on how the different mechanisms in the bladder wall react on stretching. There is a need of standardization of measurement and suggestions for this are given in the text. Pitfalls are described and how to avoid them. There is a wide range of compliance values in healthy volunteers and groups of patients. Poor compliance needs to be defined better as it can have significant clinical consequences. Prevention and treatment are discussed. CONCLUSION: If compliance is correctly measured and interpreted, it has importance in urodynamic testing and gives information relevant for clinical management.

On the nature of bladder sensation: the concept of sensory modulation.

AIMS: Going to the toilet is an essential everyday event. Normally, we do not give much thought to the sensations and factors that trigger voiding behavior: we just go. For many people, this apparently simple task is complicated and dominates their life. They have strong sensations and sudden desires to void, often resulting in incontinence. It is therefore important that we understand the origins for this functional change and identify means to alleviate it. METHODS: Literature survey. RESULTS: A considerable body of work has focused on this problem and ideas and concepts on the nature of bladder sensations are embedded in the literature. In this paper we argue the necessity to return to first principles and a re-examination of the problem. We explore the use of focus groups to identify relevant bladder sensation and what triggers 'bladder' behavior. We argue that there are differences in what can be described as 'introspective bladder sensations' and the sensations reported immediately before a void, 'void sensations'. Finally, we propose an alternative model describing how peripheral information generating 'introspective sensations' and 'void sensations' might be different but interrelated sensations. By exploring such ideas and identifying such complexity it is our intention to stimulate debate and generate further research in the field in order to understand better the physiology of bladder sensation and the pathology of increased urge, frequency and incontinence. CONCLUSIONS: Review of the literature on bladder sensation and the established ideas suggests that we might be missing something and the problem of normal and increased sensation and of urgency may be much more complex.

Changes in bladder innervation in a mouse model of Alzheimer's disease.

AIM: The aims of this study were to compare the structure of bladders from a transgenic mouse model of Alzheimer's disease with age matched control animals and to explore the idea that any structural differences might be related to functional bladder changes associated with the condition. MATERIALS AND METHODS: Two groups of mice were used. Transgenic animals in which the murine Amyloid Precursor Protein (APP) gene has been partly replaced by the human APP including both the Swedish and London mutations and that overexpress a mutant of the human Presenilin 1 gene (PS1M146L) driven by the PDGF promoter. The transgenic mice (App(SL)/PS1(M146L)) aged 24+/-3 months were used. The second group was an age matched control group of C57 black mice. The bladders from each group were isolated, fixed in 4% paraformaldehyde and prepared for immunohistochemistry. Antibodies to the vesicular acetylcholine transporter (VAChT) and neuronal nitric oxide synthase (nNOS) were used to identify neural structures. RESULTS: Cholinergic nerves (VAChT(+)) were observed in the inner and outer muscle bundles of App(SL)/PS1(M146L) and control mice. No major differences were noted in the distribution of these fibres. In contrast, there was a distinct difference in the innervation of the sub-urothelial layer. In App1(SL)/PS1(M146L) mice there were numerous VAChT and nNOS positive fibres in sharp contrast to the paucity of similar nerves in control animals. VAChT and nNOS did not appear to co-localise in the same nerve fibres within the lamina propria. Pairs of nerve fibres, nNOS(+) and VAChT(+), were observed to be intertwined and run in close proximity. A particularly unusual feature of the App(SL)/PS1(M146L) mouse bladder was the presence of neurones within the bladder wall. These nerve cell bodies were seen in all App(SL)/PS1(M146L) mouse bladders. The neurones could be found singly or in small ganglion like groups of cells and were located in all layers of the bladder wall (sub-urothelium, in the lamina propria adjacent to the inner muscle and within the inner muscle and outer muscle layers). No nerve cells or small ganglia were noted in any of the control bladders studied. CONCLUSIONS: There are structural differences in the bladders of App(SL)/PS1(M146L) mice compared to control animals. These differences are associated with sub-urothelial nerves which, because of their location, are likely to be sensory fibres. This may lead to a changed sensory processing from the App(SL)/PS1(M146L) bladders. The physiological role of the intra-mural neurones and ganglia is not known. It is speculated that they may be associated with peripheral motor/sensory mechanisms linked to the generation and modulation of sensation.

Normality of bladder filling studied in symptom-free middle-aged women.

PURPOSE: Data from cystometry and frequency volume charts were evaluated prospectively in symptom-free, middle-aged female volunteers. MATERIALS AND METHODS: A total of 32 women of the 60 who volunteered could be included with no history, symptoms or signs of urological/neurological disease. They had a mean age +/-SD of 49 +/- 6 years. They completed frequency volume charts during 3 consecutive days and underwent cystometry, including filling sensation evaluation as well as determination of electrosensation thresholds performed using standard techniques. RESULTS: Four more women had to be excluded because of clearly pathological findings on sensory evaluation. Large bladder capacity and high compliance were seen in the normal group. Data on filling sensation and the electrical sensation threshold were in the normal range. CONCLUSIONS: To compose a study group of normal volunteers of middle age requires strict inclusion and exclusion. Even then some volunteers must be excluded if pathological examination results are found. Middle-aged women have bladders with large capacity and high compliance, which can be the consequence of retaining urine during daily activities.

Study of the afferent nervous system and its evaluation in women with impaired detrusor contractility treated with bethanechol.

OBJECTIVES: To study the effects of subcutaneous bethanechol on the afferent nervous system and correlate these with the efficiency of this treatment in women with impaired detrusor contractility and to evaluate whether patients likely to respond to bethanechol can be identified before treatment through sensation evaluation. METHODS: Eighteen women with impaired detrusor contractility were given subcutaneous bethanechol for 10 days, and the flow pattern and postvoid residual urine volume were monitored. The afferent nervous system was studied before and after therapy by evaluating the sensation of filling during cystometry and by determining the bladder electrical perception threshold (EPT). RESULTS: At the end of therapy, 61% voided without a postvoid residual volume. In these women, the sensation of filling and electrical sensitivity were significantly increased compared with before treatment. In women who still voided with a postvoid residual volume, the sensation of filling had increased to a lesser extent and no change in EPT was found. Women in whom bethanechol was unsuccessful had a higher pretreatment EPT than women who were successful. No such difference was found for the sensation of filling. CONCLUSIONS: An increase in bladder sensitivity correlated with improvement in bladder emptying and can be evaluated by studying the sensation of filling and EPT. Patients likely to respond to bethanechol can be identified before treatment on the basis of the EPT level. Therefore, it would be valuable to initiate EPT measurement in the diagnosis of patients with impaired detrusor contractility.

Value of increase in bladder capacity in treatment of refractory monosymptomatic nocturnal enuresis in children.

OBJECTIVES: To evaluate children with refractory monosymptomatic nocturnal enuresis to determine whether detrusor overactivity (DOA) plays a role in 4 weeks of unsuccessful treatment with retention control training (RCT); whether an increase in bladder capacity can eventually be obtained by RCT plus oxybutynin; and whether the increase in capacity is the primary key to success. METHODS: Sixty-eight children with refractory monosymptomatic nocturnal enuresis were included. They all had a maximal cystometric capacity less than the age-expected value. RCT was done by water loading and retention to the point of urgency once daily. During training, changes in bladder capacity were evaluated by voiding charts. If after 4 weeks of RCT, less than a 10% increase in bladder capacity was noted, oral oxybutynin was added. RESULTS: The incidence of DOA was 66%. After 4 weeks of RCT, the bladder capacity increased in 20.6%. Combining RCT with oxybutynin led in the end to normalization of the bladder capacity in 79.4%. Older age and high-pressure DOA negatively influenced the ability to increase the bladder capacity. Fifteen children became completely dry, mainly by converting enuresis to nocturia. CONCLUSIONS: Unsuccessful RCT is often caused by DOA, especially if a bladder capacity rise of at least 10% cannot be achieved within 4 weeks. If oxybutynin is added to the treatment, normalization of bladder capacity can be obtained in most. This increased bladder capacity cures enuresis only in a minority by sharpening their arousal and provoking nocturia.

Cystometrical sensory data from a normal population: comparison of two groups of young healthy volunteers examined with 5 years interval.

OBJECTIVE: To describe the pattern of sensations reported during standardized cystometry in a group of healthy young volunteers and compare them with a group examined 5 years before. METHODS: A group of 50 young healthy volunteers without any symptoms or history reported the sensations they felt during cystometry. These results were compared with those of another group of 38 young healthy volunteers examined in the same lab in 1995 by another investigator. RESULTS: All participants perceived a first sensation of bladder filling, first desire to void and strong desire to void. Each sensation was easily distinguishable from the others. The volumes at which these sensations came up varied widely. The ratio between volumes at consecutive sensations and at full bladder was fairly constant. All but two parameters were not significantly different from those found in 1995. CONCLUSIONS: Our data give additional weight to previous findings that there exists a normal pattern of sensations reported during cystometric bladder filling. This sensory pattern probably corresponds with specific physiological mechanisms as suggested before. Deviations from this pattern indicate or illustrate pathology.

Can the sensory threshold toward electrical stimulation be used to quantify the subjective perception of bladder filling? A study in young healthy volunteers.

OBJECTIVES: To evaluate whether electrosensation can be used as a quantitative measurement for the sensations felt during bladder distension. METHODS: A total of 48 healthy volunteers were examined. Sensations of bladder distension were evaluated during medium-fill cystometry. Electrosensation was quantified by obtaining electrical thresholds at different sites in the lower urinary tract with constant current stimulation at 2.5 and 95 Hz. RESULTS: Both currents were perceived differently. Thresholds at 95 Hz were significantly higher than at 2.5 Hz for each location. With neither current could a significant correlation be found between the parameters of filling perception and electrosensation in the lower urinary tract. CONCLUSIONS: Although the use of electrical thresholds is a valuable technique in the diagnosis of neuropathic disorders in the lower urinary tract, at the current settings it cannot be used to quantify the perception of bladder filling.

Does bladder tone influence sensation of filling and electro-sensation in the bladder? A blind controlled study in young healthy volunteers using bethanechol.

PURPOSE: The influence of bladder tone on filling sensation and electro-sensation in the bladder was studied in young healthy volunteers. MATERIALS AND METHODS: A total of 22 healthy volunteers 18 to 30 years old were included in our study, of whom 15 received a subcutaneous injection of 5 mg bethanechol and 7 received a subcutaneous injection of water to serve as randomly selected controls. In each group filling perception was evaluated during medium fill cystometry before and 25 minutes after injection. The bladder electrical threshold was determined in each group by constant current stimulation before and 25 minutes after injection. RESULTS: In the study group there was a marked decrease in the volume at which various filling sensations occurred after bethanechol was given. The pressure at which all filling sensations were perceived was higher after bethanechol than at baseline cystometry. The electrical threshold decreased with bethanechol. In the control group no change was noted in the perception of filling or electro-sensation. CONCLUSIONS: Bethanechol has a distinct influence on the filling sensation and on electrical bladder stimulation. Each sensation is sharpened after the administration of bethanechol. Several hypotheses are possible to explain these effects.