Chapter 2: Pathophysiology of neurogenic detrusor overactivity and the symptom complex of "overactive bladder"

Determination of tibial somatosensory evoked potentials predicts detrusor sphincter dyssynergia in children with neurogenic bladder dysfunction

INTRODUCTION

Tibial somatosensory evoked potentials (SEP) are used to identify the neurological status and tethered cord (TC) in patients with spina bifida (SB). Its significance in contributing to the interpretation of urodynamics to determine bladder status is unknown. This study aimed to determine the correlation between SEP and urodynamics in children with SB.

MATERIAL AND METHODS

SEP and urodynamic results, for differential diagnosis of TC, were evaluated. SEP scores were correlated with urodynamic findings. SEP results were scored from 1 to 6, with 1, denoting a favorable score and 6, an unfavorable score. Age, gender, detrusor, and sphincter activities in urodynamics were noted. Results were analyzed using the χ² test and logistic regression analysis. Receiver operating characteristic (ROC) curve was formed to get a valid threshold for the SEP score to predict the urodynamic condition.

RESULTS

There were 44 SB patients for whom SEP was done for differential diagnosis of TC. Fifteen patients who did not meet the inclusion criteria were excluded from the study. SB aperta was present in 17 patients and occulta in 12, respectively. The patients had a mean age of 6.6 ± 3.2 years. There were 13 boys and 16 girls. A strong correlation was found between high SEP scores and detrusor sphincter dyssynergia (p < 0.001). A SEP score over 3.5 was found to be 93% sensitive and 73% specific to predict this correlation. There was no relationship between detrusor activity and SEP scores (p = 0.18).

DISCUSSION

Tibial SEP is an important noninvasive adjunct tool for the diagnosis of TC in patients with SB. Urodynamic studies are the gold standard in the evaluation of bladder status in neurogenic bladder dysfunction due to SB. Detrusor sphincter dyssynergia may be regarded as a sign of severe spinal cord injury in these patients.

CONCLUSION

Our findings suggest that in children with neurogenic bladder, high SEP scores may predict the presence of detrusor sphincter dyssynergia but not the status of detrusor function while providing pathophysiological evidence for neural injury.

The biopsychosocial impacts of anxiety on overactive bladder in women

AIMS

Links between emotional state and the bladder have long been recognized, as psychological comorbidity is a common feature of overactive bladder (OAB). However, how psychological factors might contribute to the development and severity of OAB remains unclear. Therefore, we sought to examine the effect of anxiety on OAB with a specific focus on bladder hypersensitivity.

METHODS

In a sample of 120 adult women with OAB, we compared those with at least mild anxiety (PROMIS Anxiety score ≥55) to those with lower anxiety. Analyses focused on patient-reported questionnaires assessing urinary symptom severity and quality of life, psychological stress symptoms, general somatic symptoms, and results of quantitative sensory testing (QST), including temporal summation to heat pain (TSP). TSP was used to index elevated C-fiber responsiveness (i.e., central sensitization).

RESULTS

Thirty-six (30%) women had at least mild anxiety. While there were no group differences for urinary symptom severity, more anxious women reported worse OAB-specific quality of life, greater psychological stress burden, higher stress reactivity, and greater somatic symptoms. On QST, there were no differences between anxiety groups for pain threshold (43.6 ± 3.1°C vs. 44.0 ± 3.1°C, p = 0.6) and tolerance (47.3 ± 1.5°C vs. 47.4 ± 1.6°C, p = 0.7). However, those with anxiety had significantly higher TSP than those without anxiety (6.0 ± 4.8 vs. 3.7 ± 3.9, p = 0.006), indicating greater central sensitization.

CONCLUSIONS

Women with OAB and at least mild anxiety symptoms reported greater psychosocial burdens (i.e., psychological stress, stress reactivity, OAB-specific QOL) and somatic symptom severity and demonstrated greater central sensitization on QST than those without anxiety. These findings support the hypothesis that anxiety and psychological stress impact hypersensitivity mechanisms that may underlie and contribute to OAB, although further research is needed to better understand how and to what extent.

The pathophysiology of Post SSRI Sexual Dysfunction - Lessons from a case study

BACKGROUND

Although Post-SSRI Sexual Dysfunction (PSSD) has finally been recognized by the European Medicines Agency as a medical condition that can outlast discontinuation of SSRI and SNRI antidepressants, this condition is still largely unknown by patients, doctors, and researchers, and hence, poorly understood, underdiagnosed, and undertreated.

OBJECTIVE

Becoming familiar with the symptomatology of PSSD and understanding the underlying mechanisms and treatment options.

METHOD

We applied a design thinking approach to innovation to 1) provide insights into the medical condition as well as the personal needs and pains of a targeted patient; and 2) generate ideas for new solutions from the perspective of this particular patient. These insights and ideas informed a literature search on the potential pathophysiological mechanisms that could underlie the patient's symptoms.

RESULTS

The 55-year-old male patient developed symptoms of low libido, delayed ejaculation, erectile dysfunction, 'brain zaps', overactive bladder and urinary inconsistency after discontinuation of the SNRI venlafaxine. In many of these symptoms a dysregulation in serotonergic activity has been implicated, with an important role of 5-HT_1A receptor downregulation and possible downstream effects on neurosteroid and oxytocin systems.

CONCLUSIONS

The clinical presentation and development of symptoms are suggestive of PSSD but need further clinical elaboration. Further knowledge of post-treatment changes in serotonergic - and possibly noradrenergic - mechanisms is required to improve our understanding of the clinical complaints and to inform appropriate treatment regimes.

Urinary Symptoms Are Unrelated to Leukocyte Esterase and Nitrite Among Indwelling Catheter Users

Objectives

To explore the association between dipstick results and urinary symptoms.

Method

This was a prospective 12-month observational study of real-time self-administered urine dipstick results and symptoms in a community setting that included 52 spinal cord injury/disease (SCI/D) participants with neurogenic lower urinary tract dysfunction (NLUTD) who use an indwelling catheter. Symptoms were collected using the Urinary Symptom Questionnaire for Neurogenic Bladder-Indwelling Catheter (USQNB-IDC). The USQNB-IDC includes actionable (A), bladder (B1), urine quality (B2), and other (C) symptoms; analyses focused on A, B1, and B2 symptoms. Dipstick results include nitrite (NIT +/-), and leukocyte esterase (LE; negative, trace, small, moderate, or large). Dipstick outcomes were defined as strong positive (LE = moderate/large and NIT+), inflammation positive (LE = moderate/large and NIT-), negative (LE = negative/trace and NIT-), and indeterminate (all others).

Results

Nitrite positive dipsticks and moderate or large LE positive dipsticks were each observed in over 50% of the sample in every week. Strong positive dipstick results were observed in 35% to 60% of participants in every week. A, B1, or B2 symptoms co-occurred less than 50% of the time with strong positive dipsticks, but they also co-occurred with negative dipsticks. Participants were asymptomatic with a strong positive dipstick an average of 30.2% of the weeks. On average, 73% of the time a person had a negative dipstick, they also had no key symptoms (95% CI, .597-.865).

Conclusion

No association was observed between A, B1, and B2 symptoms and positive dipstick. A negative dipstick with the absence of key symptoms may better support clinical decision-making.

Effect of β3-adrenoceptor agonist on the micromotion of bilateral major pelvic ganglion-excised rat bladder

AIMS

Micromotion is an autonomous intramural movement of the bladder, and is believed to be an initial step in the generation of urinary urgency. Therefore, controlling micromotion may be a novel target in overactive bladder (OAB) treatment. However, developing micromotion treatment has been limited by the absence of a standardized animal model. We attempted to create a micromotion animal model and investigated the effectiveness of a β₃ -adrenoceptor agonist (CL316,243) on micromotion.

METHODS

Bilateral major pelvic ganglia (MPGs) were excised in 18 male Sprague-Dawley rats, resulting in an almost completely denervated bladder. On postoperative Day 7, cystometry was performed. Rats were divided into three treatment groups: CL316,243; β_3- adrenoceptor antagonist (SR59230A) pretreated CL316,243; and a nonselective antimuscarinic agent (oxybutynin). Changes in micromotion were evaluated after the intra-arterial administration of each agent.

RESULTS

Low-amplitude oscillations in intravesical pressure (micromotion) were observed 1 week after MPGs excision. Micromotion frequency significantly (p = 0.003) decreased (2.17 ± 3.54 times/5 min) with CL316,243 compared with vehicle (6.33 ± 1.97 times/5 min). Micromotion amplitude also decreased with CL316,243 (1.15 ± 1.93 cmH₂ O) compared with vehicle (5.96 ± 5.12 cmH₂ O), approaching conventional significance (p = 0.090). No significant decreases in frequency or amplitude were observed with oxybutynin treatment.

CONCLUSIONS

Systemic administration of the β₃ -adrenoceptor agonist CL316,243 effectively controlled micromotion in bilateral MPGs-excised, almost completely denervated rat bladders. This result indicates that β₃ -adrenoceptor agonist may affect the bladder directly, suggesting that it might be effective for overall OAB, regardless of the presence or level of neurological deficits. Bilateral MPGs-excised rats are considered a plausible micromotion animal model suitable for future research.

Piezo channels in the urinary system

The Piezo channel family, including Piezo1 and Piezo2, includes essential mechanosensitive transduction molecules in mammals. Functioning in the conversion of mechanical signals to biological signals to regulate a plethora of physiological processes, Piezo channels, which have a unique homotrimeric three-blade propeller-shaped structure, utilize a cap-motion and plug-and-latch mechanism to gate their ion-conducting pathways. Piezo channels have a wide range of biological roles in various human systems, both in vitro and in vivo. Currently, there is a lack of comprehensive understanding of their antagonists and agonists, and therefore further investigation is needed. Remarkably, increasingly compelling evidence demonstrates that Piezo channel function in the urinary system is important. This review article systematically summarizes the existing evidence of the importance of Piezo channels, including protein structure, mechanogating mechanisms, and pharmacological characteristics, with a particular focus on their physiological and pathophysiological roles in the urinary system. Collectively, this review aims to provide a direction for future clinical applications in urinary system diseases.

Overactive bladder: A review and update

Overactive bladder syndrome is a chronic, disabling condition with physical, psychological and social consequences that significantly affects the quality of life of millions of patients worldwide. The economic impact of this disorder is crucial. Overactive bladder syndrome is a little-known condition, with different manifestations from patient to patient, which causes a great deal of frustration to the medical staff involved. The patient requires a clear explanation and the full support of the attending physician. It is extremely important to establish a correct diagnosis and an effective individualized treatment. The collaboration and understanding of these patients are extremely important aspects. Improving the quality of life in these patients is the main purpose in managing this condition. There are several treatment modalities that may be used progressively, with favorable albeit inconsistent results. This condition remains extremely challenging for specialists and, unfortunately, always one of maximum interest.

Current Management of Post-radical Prostatectomy Urinary Incontinence

Prostate cancer is the second most common cancer in men worldwide. Radical prostatectomy and radiation beam therapy are the most common treatment options for localized prostate cancer and have different associated complications. The etiology of post prostatectomy incontinence is multifactorial. There is evidence in the literature that anatomic support and pelvic innervation are important factors in the etiology of post-prostatectomy incontinence. Among the many surgical and technical factors proposed in the literature, extensive dissection during surgery, damage to the neurovascular bundle and the development of postoperative fibrosis have a substantial negative impact on the continence status of men undergoing RP. Sparing of the bladder neck and anterior, and possibly posterior, fixation of the bladder-urethra anastomosis are associated with better continence rates. Overactive bladder syndrome (OAB) is multifactorial and the exact role of prostate surgery in the development of OAB is still under debate. There are several variables that could contribute to detrusor overactivity. Detrusor overactivity in patients after radical prostatectomy has been mainly attributed to a partial denervation of the bladder during surgery. However, together with bladder denervation, other hypotheses, such as the urethrovesical mechanism, have been described. Although there is conflicting evidence regarding the importance of conservative treatment after post-prostatectomy urinary incontinence, pelvic floor muscle training (PFMT) is still considered as the first treatment choice. Duloxetin, either alone or in combination with PFMT, may hasten recovery of urinary incontinence but is often associated with severe gastrointestinal and central nervous side effects. However, neither PFMT nor duloxetine may cure male stress urinary incontinence. The therapeutic decision and the chosen treatment option must be individualized for each patient according to clinical and social factors. During the recent years, the development of new therapeutic choices such as male sling techniques provided a more acceptable management pathway for less severe forms of urinary incontinence related to radical prostatectomy. Following this perspective, technological improvements and the emergence of new dedicated devices currently create the premises for a continuously positive evolution of clinical outcomes in this particular category of patients.

The Telocytes: Ten Years after Their Introduction in the Scientific Literature. An Update on Their Morphology, Distribution, and Potential Roles in the Gut

Ten years ago, the term 'telocyte' was introduced in the scientific literature to describe a 'new' cell type described in the connective tissue of several organs by Popescu and Faussone-Pellegrini (2010). Since then, 368 papers containing the term 'telocyte' have been published, 261 of them in the last five years. These numbers underscore the growing interest in this cell type in the scientific community and the general acceptance of the name telocyte to indicate this interstitial cell. Most of these studies, while confirming the importance of transmission electron microscopy to identify the telocytes with certainty, highlight the variability of their immune phenotypes. This variability was interpreted as due to (i) the ability of the telocytes to adapt to the different sites in which they reside; (ii) the distinct functions they are likely to perform; and (iii) the existence of telocyte subtypes. In the present paper, an overview of the last 10 years of literature on telocytes located in the gut will be attempted, confining the revision to the morphological findings. A distinct chapter will be dedicated to the recently hypothesized role of the telocytes the intestinal mucosa. Through this review, it will be shown that telocytes, despite their variability, are a unique interstitial cell.

Neurogenic lower urinary tract dysfunction predicts prognosis in patients with multiple system atrophy

PURPOSE

To evaluate whether neurogenic lower urinary tract dysfunction and urodynamic parameters predict the outcomes of patients with multiple system atrophy (MSA).

METHODS

A retrospective study was performed in patients who were diagnosed with MSA and underwent urodynamic studies simultaneously from September 2014 to July 2018. The urodynamic traces were reviewed by urologists. Detrusor contractility was evaluated by the bladder contractility index (BCI) and Schäfer nomogram. Telephone follow-up was conducted in July 2019 to acquire survival data. Clinical and urodynamic parameters were analyzed for survival using Cox regression analysis.

RESULTS

Overall, 70 MSA patients were eligible for analysis, and 61 of them underwent urodynamic study within 3 years of initial symptom onset. The parkinsonian subtype of MSA (MSA-P) had a smaller proportion of men as well as longer motor and lower urinary tract symptom durations than the cerebellar subtype (MSA-C). MSA-P also had a lower mean BCI than MSA-C (32.0 ± 27.0 versus 53.6 ± 33.4, p = 0.025). The mean MSA survival time was 5.4 [95% confidence interval (CI) 4.8-6.3] years. Cox regression analysis showed that survival from baseline was correlated only with BCI [hazard ratio (HR) 0.983, 95% CI 0.969-0.997, p = 0.020]. Overall survival was correlated with BCI (HR 0.982, 95% CI 0.966-0.999, p = 0.039) and the presence of urinary incontinence (HR 3.007, 95% CI 0.993-9.220, p = 0.052).

CONCLUSION

Detrusor contractility can be a prognostic marker in MSA patients. A high BCI value is a protective factor for survival from baseline and overall survival. The presence of urinary incontinence predicts shortened overall survival.

The Botulinum Treatment of Neurogenic Detrusor Overactivity: The Double-Face of the Neurotoxin

Botulinum neurotoxin (BoNT) can counteract the highly frequent involuntary muscle contractions and the uncontrolled micturition events that characterize the neurogenic detrusor overactivity (NDO) due to supra-sacral spinal cord lesions. The ability of the toxin to block the neurotransmitter vesicular release causes the reduction of contractions and improves the compliance of the muscle and the bladder filling. BoNT is the second-choice treatment for NDO once the anti-muscarinic drugs have lost their effects. However, the toxin shows a time-dependent efficacy reduction up to a complete loss of activity. The cellular mechanisms responsible for BoNT effects exhaustion are not yet completely defined. Similarly, also the sites of its action are still under identification. A growing amount of data suggest that BoNT, beyond the effects on the efferent terminals, would act on the sensory system recently described in the bladder mucosa. The specimens from NDO patients no longer responding to BoNT treatment displayed a significant increase of the afferent terminals, likely excitatory, and signs of a chronic neurogenic inflammation in the mucosa. In summary, beyond the undoubted benefits in ameliorating the NDO symptomatology, BoNT treatment might bring to alterations in the bladder sensory system able to shorten its own effectiveness.

Nerve sprouting and neurogenic inflammation characterize the neurogenic detrusor overactive bladder of patients no longer responsive to drug therapies

Urothelium and Lamina Propria (LP) are considered an integrate sensory system which is able to control the detrusor activity. Complete supra-sacral spinal cord lesions cause Neurogenic Detrusor Overactivity (NDO) whose main symptoms are urgency and incontinence. NDO therapy at first consists in anti-muscarinic drugs; secondly, in intra-vesical injection of botulinum toxin. However, with time, all the patients become insensitive to the drugs and decide for cystoplastic surgery. With the aim to get deeper in both NDO and drug's efficacy lack pathogenesis, we investigated the innervation, muscular and connective changes in NDO bladders after surgery by using morphological and quantitative methodologies. Bladder innervation showed a significant global loss associated with an increase in the nerve endings located in the upper LP where a neurogenic inflammation was also present. Smooth muscle cells (SMC) anomalies and fibrosis were found in the detrusor. The increased innervation in the ULP is suggestive for a sprouting and could condition NDO evolution and drug efficacy length. Denervation might cause the SMC anomalies responsible for the detrusor altered contractile activity and intra-cellular traffic and favour the appearance of fibrosis. Inflammation might accelerate these damages. From the clinical point of view, an early anti-inflammatory treatment could positively influence the disease fate.

A Comprehensive Review of Overactive Bladder Pathophysiology: On the Way to Tailored Treatment

CONTEXT

Current literature suggests that several pathophysiological factors and mechanisms might be responsible for the nonspecific symptom complex of overactive bladder (OAB).

OBJECTIVE

To provide a comprehensive analysis of the potential pathophysiology underlying detrusor overactivity (DO) and OAB.

EVIDENCE ACQUISITION

A PubMed-based literature search was conducted in April 2018, to identify randomised controlled trials, prospective and retrospective series, animal model studies, and reviews.

EVIDENCE SYNTHESIS

OAB is a nonspecific storage symptom complex with poorly defined pathophysiology. OAB was historically thought to be caused by DO, which was either "myogenic" (urgency initiated from autonomous contraction of the detrusor muscle) or "neurogenic" (urgency signalled from the central nervous system, which initiates a detrusor contraction). Patients with OAB are often found to not have objective evidence of DO on urodynamic studies; therefore, alternative mechanisms for the development of OAB have been postulated. Increasing evidence on the role of urothelium/suburothelium and bladder afferent signalling arose in the early 2000s, emphasising an afferent "urotheliogenic" hypothesis, namely, that urgency is initiated from the urothelium/suburothelium. The urethra has also recently been regarded as a possible afferent origin of OAB-the "urethrogenic" hypothesis. Several other pathophysiological factors have been implicated, including metabolic syndrome, affective disorders, sex hormone deficiency, urinary microbiota, gastrointestinal functional disorders, and subclinical autonomic nervous system dysfunctions. These various possible mechanisms should be considered as contributing to diagnostic and treatment algorithms.

CONCLUSIONS

There is a temptation to label OAB as "idiopathic" without obvious causation, given the poorly understood nature of its pathophysiology. OAB should be seen as a complex, multifactorial symptom syndrome, resulting from multiple potential pathophysiological mechanisms. Identification of the underlying causes on an individual basis may lead to the definition of OAB phenotypes, paving the way for personalised medical care.

PATIENT SUMMARY

Overactive bladder (OAB) is a storage symptom syndrome with multiple possible causes. Identification of the mechanisms causing a patient to experience OAB symptoms may help tailor treatment to individual patients and improve outcomes.

Management of Overactive Bladder Symptoms After Radical Prostatectomy

PURPOSE OF REVIEW

Post-prostatectomy overactive bladder (OAB) is a common and challenging condition to manage. The aim of the present report was to review the recent evidences regarding OAB symptoms that develop in men after prostatectomy and how to manage them.

RECENT FINDINGS

The prevalence of OAB after radical prostatectomy may range from 15.2 to 37.8%. Recent studies have highlighted the role of the urethrogenic mechanism (facilitation of the urethrovesical reflex due to stress urinary incontinence (SUI)) in the genesis of post-prostatectomy OAB in a significant proportion of patients. Several other pathophysiological factors such as iatrogenic decentralization of the bladder, defunctionalized bladder due to severe SUI, detrusor underactivity, or bladder outlet obstruction might be involved. The evaluation should aim to identify the underlying mechanism to tailor the treatment, which could range from SUI surgery, to fixing a urethral stricture, improving bladder emptying or using the conventional spectrum of OAB therapies. There is a paucity of data for OAB therapies specific to post-prostatectomy patients, with the exception of solifenacin, tolterodine, and botulinum toxin. There is currently no data on how preoperative management or surgical technique may prevent post-prostatectomy OAB.

The Expanding Therapeutic Utility of Botulinum Neurotoxins

Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.

Managing Polypharmacy in the 15-Minute Office Visit

Polypharmacy is an underappreciated factor in undesirable patient outcomes. In older adults, polypharmacy is considered a syndrome of harm and presents a challenge to primary care providers. The United States has one of the highest medication use rates per capita in the world. With the aging population, and polypharmacy a significant part of the lives of older adults, management of polypharmacy poses both a growing challenge and an opportunity for all health care providers. This article provides an overview of skills to improve medication use management in older adults living with polypharmacy.

Women Undergoing Third Line Overactive Bladder Treatment Demonstrate Elevated Thermal Temporal Summation

PURPOSE

We sought to determine whether women with overactive bladder who required third line therapy would demonstrate greater central sensitization, indexed by temporal summation to heat pain stimuli, than those with overactive bladder.

MATERIALS AND METHODS

We recruited 39 women with overactive bladder from the urology clinic who were planning to undergo interventional therapy for medication refractory overactive bladder with onabotulinumtoxinA bladder injection or sacral neuromodulation. We also recruited 55 women with overactive bladder who were newly seen at our urology clinic or who responded to advertisements for study participation. Participants underwent quantitative sensory testing using a thermal temporal summation protocol. The primary study outcome was the degree of temporal summation as reflected in the magnitude of positive slope of the line fit to the series of 10 stimuli at a 49C target temperature. We compared the degree of temporal summation between the study groups using linear regression.

RESULTS

Women in the group undergoing third line therapy showed significantly higher standardized temporal summation slopes than those in the nontreatment group (β = 1.57, 95% CI 0.18-2.96, t = 2.25, p = 0.027). On exploratory analyses a history of incontinence surgery or hysterectomy was associated with significantly greater temporal summation.

CONCLUSIONS

In this study the degree of temporal summation was elevated in women undergoing third line overactive bladder therapy compared to women with overactive bladder who were not undergoing that therapy. These findings suggest there may be pathophysiological differences, specifically in afferent nerve function and processing, in some women with overactive bladder.

Increased Expression of TREK-1 K+ Channel in the Dorsal Root Ganglion of Rats with Detrusor Overactivity After Partial Bladder Outlet Obstruction

Background

Changes in expression and activity of ion channels are important pathophysiological mechanisms underlying detrusor overactivity (DO) in partial bladder outlet obstruction (PBOO). The objective of this study was to examine the expression of TREK-1 channel in the bladder and central nervous system of DO rats.

Material/Methods

Thirty Sprague-Dawley rats were subjected to PBOO operations and those displaying non-voiding contractions (NVCs) in cystometry were classified as DO. Sham-operated rats without NVCs in cystometry served as controls. The expression and distribution of TREK-1 in the bladder, spinal cord, and dorsal root ganglion (DRG) were detected by real time-PCR, western blot, and immunohistochemistry.

Results

TREK-1 channel expression in the DRG was significantly increased at the mRNA level (11.20±3.762 vs. 3.209±1.505, P<0.01) and protein level (2.195±0.058 vs. 1.713±0.066, P<0.01) in DO rats as compared to control rats. However, the expression of TREK-1 mRNA in the bladder (1.380±0.810 vs. 4.206±3.827, P>0.05) and spinal cord (0.764±0.357 vs. 0.696±0.188, P>0.05) was comparable between the 2 groups. Immunohistochemistry showed enhanced immunoreactive signals of TREK-1 channel in the DRG, but not in the spinal cord and bladder.

Conclusions

TREK-1 channel was upregulated in the DRG of DO rats after chronic PBOO, which might suppress neuronal excitability and play a protective role in bladder overactivity in PBOO.

Adaptive changes of telocytes in the urinary bladder of patients affected by neurogenic detrusor overactivity

Urinary bladder activity involves central and autonomic nervous systems and bladder wall. Studies on the pathogenesis of voiding disorders such as the neurogenic detrusor overactivity (NDO) due to suprasacral spinal cord lesions have emphasized the importance of an abnormal handling of the afferent signals from urothelium and lamina propria (LP). In the LP (and detrusor), three types of telocytes (TC) are present and form a 3D-network. TC are stromal cells able to form the scaffold that contains and organizes the connective components, to serve as guide for tissue (re)-modelling, to produce trophic and/or regulatory molecules, to share privileged contacts with the immune cells. Specimens of full thickness bladder wall from NDO patients were collected with the aim to investigate possible changes of the three TC types using histology, immunohistochemistry and transmission electron microscopy. The results show that NDO causes several morphological TC changes without cell loss or network interruption. With the exception of those underlying the urothelium, all the TC display signs of activation (increase in Caveolin1 and caveolae, αSMA and thin filaments, Calreticulin and amount of cisternae of the rough endoplasmic reticulum, CD34, euchromatic nuclei and large nucleoli). In all the specimens, a cell infiltrate, mainly consisting in plasma cells located in the vicinity or taking contacts with the TC, is present. In conclusion, our findings show that NDO causes significant changes of all the TC. Notably, these changes can be interpreted as TC adaptability to the pathological condition likely preserving each of their peculiar functions.

Micturition dysfunction in four-month old ovariectomized rats: Effects of testosterone replacement

AIMS

Androgen deficiency has been implicated in urological complications of postmenopausal women. This study examined the effects of testosterone replacements on the lower urinary tract dysfunction in 4-month old ovariectomized (OVX) rats.

MAIN METHODS

Sprague-Dawley female rats were OVX bilaterally. Three months later, rats received single intramuscular injections of testosterone undecanoate. Cystometric study, and bladder and urethra smooth muscle reactivities were evaluated.

KEY FINDINGS

Ovariectomy reduced by 65% (p<0.05) the serum testosterone levels. Testosterone replacement at 5mg/kg restored serum hormone levels to baseline, whereas 10mg/kg produced 14-fold higher testosterone levels. OVX rats exhibited significant increases of body weight, perigonadal fat and blood pressure, and reduced uterus weight, but none of these parameters were changed by testosterone replacements. OVX rats exhibited micturition dysfunction characterized by increases of basal pressure, threshold pressure, voiding frequency and post-voiding pressure. In addition, the bladder contractions induced by electrical-field stimulation (EFS) and carbachol were significantly reduced, whereas angiotensin II-induced urethral contractions were significantly increased in OVX rats. Testosterone replacement at 10mg/kg (but not at 5mg/kg) dose fully normalized the in vivo micturition dysfunction, as well as the in vitro bladder and urethral alterations. Testosterone (10mg/kg) also significantly potentiated the bladder relaxations induced by the β₃-adrenoceptor agonist mirabegron. The protective effects of testosterone were not modified by concomitant treatment with the aromatase inhibitor letrozole (2.5mg/kg, 4weeks).

SIGNIFICANCE

The improvement of micturition dysfunction by testosterone replacement suggests that androgen therapy might be of therapeutic benefit for urological complications associated with post-menopause.

Evaluation of Overactive Bladder in Male Antidepressant Users: A Prospective Study

PURPOSE

In this study, we investigated overactive bladder (OAB) functions in male patients who used antidepressant drugs (ADs) that were previously examined in female patients, based on conflicting data in literature regarding the effects of AD on OAB and the differences between male and female urinary system physiologies (anatomical and hormonal).

METHODS

The study included 202 male patients (a control group of 90 healthy subjects, and an experimental group of 112 patients taking ADs for different disorders). All the patients completed the overactive bladder-validated 8 (OAB-V8) questionnaire, the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), and the Beck Depression Inventory (BDS).

RESULTS

The OAB-V8, ICIQ-SF, and BDS scores for the antidepressant users were significantly higher than those of the control group. The highest prevalence of OAB symptoms was observed in patients taking venlafaxine (68.2%), and the lowest prevalence was in patients taking sertraline (28.0%). Moreover, the frequency of OAB between the antidepressant groups was statistically significant. The univariate logistic regression analyses showed a significant relationship between the presence of OAB, antidepressant usage, BDS score, and the age of a patient. In the multivariate logistic regression analyses, the association between the presence of OAB and antidepressant usage was statistically significant.

CONCLUSIONS

The present study showed that the incidence of OAB and the severity of OAB symptoms increased in males using antidepressants for various disorders. This may have been due to unique pharmacological effects, on a molecular or individual level, of serotonin-norepinephrine reuptake inhibitors.

The effect of EMG biofeedback assisted pelvic floor muscle therapy on symptoms of the overactive bladder syndrome in women: A randomized controlled trial

AIMS

The overactive bladder syndrome (OAB) is defined as urinary urgency, usually accompanied by frequency and nocturia, with or without urgency urinary incontinence. Biofeedback-assisted pelvic muscle therapy (BAPFMT) is a first-line treatment option for OAB. The aims of this study were to determine the efficacy and effectiveness of BAPFMT on symptoms of OAB after 9 weeks of treatment and to detect changes EMG activity of individual pelvic floor muscles (PFM) with the MAPLe.

METHODS

Patients were randomly divided into an intervention group that received BAPFMT with the MAPLe or into a control group which received only toilet behavior and lifestyle instructions. The Pelvic Floor Inventories (PeLFIs), the King's Health Questionnaire (KHQ), a voiding dairy, a 24 h pad-test, and vaginal EMG registration of the pelvic floor with the MAPLe were used at inclusion and after 9 weeks follow-up to determine the effect of BAPFMT on complaints of OAB and Quality of Life (QoL).

RESULTS

Fifty-eight patients were included. The PeLFIs, KHQ, voiding dairy, and 24 h pad-test showed significant improvements in the intervention group compared to the control group in complaints of OAB and QoL. EMG activity showed significant improvements for specific individual muscles at the different sides and depths for rest, maximal voluntary contraction, and endurance.

CONCLUSIONS

EMG BAPFMT is effective in the OAB syndrome in women. It significantly reduces symptoms and complaints of OAB and increases QoL for patients. It shows that EMG changes in individual PFM, measured with the MAPLe, are relevant and related to symptom reduction.

An exploratory study for bladder dysfunction in atypical antipsychotic-emergent urinary incontinence

INTRODUCTION

This is an exploratory study, which aimed to analyze urodynamic findings in patients who are on atypical antipsychotics and present with urinary incontinence (UI) in order to understand the mechanisms of antipsychotic-emergent UI.

PATIENTS AND METHODS

Eight patients (34 ± 7.6 years; five males and three females) diagnosed with schizophrenia or other psychotic disorders, who were on risperidone, olanzapine, or clozapine monotherapy and having UI were recruited. Urodynamic study was performed in all patients.

RESULTS

Six out of eight (75%) patients had abnormal urodynamic findings. Three of them had detrusor overactivity (DO) without detrusor-sphincter dyssynergia (DSD); two had DO with DSD; and one had hypoactive detrusor with nonrelaxing sphincter during void phase. The common urinary symptoms were urgency, enuresis, and straining to void urine. Significant postvoid residual urine was found in two patients.

CONCLUSION

The evidence of bladder dysfunction in atypical antipsychotic-emergent UI is similar to that present in patients with neurological disorders. Urinary complaints in patients on antipsychotics thus need to be evaluated and managed systematically using the protocol followed for neurological conditions.

Does central sensitization help explain idiopathic overactive bladder?

The pathophysiological mechanisms underlying overactive bladder syndrome (OAB) can include dysfunction of sensory pathways of the peripheral and central nervous systems, resulting in bladder hypersensitivity. Central sensitization describes an induced state of spinal hypersensitivity that is associated with a variety of chronic pain disorders that share many attributes with OAB, albeit without the presence of pain. As such, the concept of central sensitization might be relevant to understanding the mechanisms and clinical manifestations of OAB syndrome. An understanding of the pathophysiology and clinical manifestations of central sensitization, and the evidence that supports a role of central sensitization in OAB, including the potential implications of mechanisms of central sensitization for the treatment of patients with OAB could provide a novel approach to the treatment of patients with this disease. Such an approach would be especially relevant to those patients with central sensitization-related comorbidities, and has the potential to improve the outcomes of these patients in particular.

Temporal summation to thermal stimuli is elevated in women with overactive bladder syndrome

INTRODUCTION

This study sought to provide a preliminary assessment of whether spinally mediated afferent hyperactivity (i.e., central sensitization) might contribute to manifestations of overactive bladder syndrome (OAB) in women as indexed by elevated temporal summation of evoked heat pain stimuli.

METHODS

We recruited 20 adult women with OAB who were planning to undergo interventional therapy for OAB with either onabotulinumtoxinA injection or sacral neuromodulation and 23 healthy controls without OAB symptoms to undergo quantitative sensory testing with cutaneous thermal pain temporal summation. The primary study outcome was the degree of temporal summation, as reflected in the magnitude of positive slope of the line fitted to the series of 10 stimuli at the 49°C target temperatures. Linear regression and analysis of covariance were utilized to compare the degree of temporal summation between study groups.

RESULTS

The standardized slope of temporal summation trials for women with OAB was significantly higher than for controls (β = 3.43, 95% confidence interval = 0.6-6.2, P = 0.017). The adjusted means ±SE of the standardized temporal summation slopes for the full OAB and control groups were 3.0 ± 0.5 (95% confidence interval = 2.0, 4.1) and 1.7 ± 0.5 (95% confidence interval = 0.7, 2.7), respectively.

CONCLUSION

In this preliminary study, we demonstrated that women with OAB refractory to primary and secondary therapies exhibited greater thermal cutaneous temporal summation than women without OAB symptoms. This suggests that central sensitization, indexed by temporal summation, may be an underlying factor contributing to OAB in some women. Neurourol. Urodynam. 36:1108-1112, 2017. © 2016 Wiley Periodicals, Inc.

Efficacy and safety of botulinum toxin injection for interstitial cystitis/bladder pain syndrome: a systematic review and meta-analysis

PURPOSE

To investigate the overall treatment efficacy and safety of botulinum toxin type A (BoNTA) injections compared with placebo in interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

We conducted a systematic review and meta-analysis of the published literature in PubMed, Cochrane Library, and EMBASE on BoNTA use in IC/BPS. Outcome measures included changes of OLS, ICSI, ICPI, VAS, frequency, nocturia, FBC, Qmax, and PVR from baseline and also included adverse events.

RESULTS

A total of five studies were included, with a total sample size of 252 subjects (133 subjects in the experimental group and 119 subjects in the control group). The duration of follow-up ranged from 8 to 12 weeks. The BoNTA dosage was from 50 to 200 U. The pooled overall SMD in the mean change of VAS for the BoNTA group versus the placebo group was -0.49 (95 % CI -0.74, -0.23). There were also significant improvements in ICPI and frequency. The other outcomes (ICSI, nocturia, Qmax, and FBC) were not statistically different between the two groups.

CONCLUSION

Although BoNTA is not regulatory approved indication, this first evidence-based systematic review and meta-analysis of BoNTA injection for IC/BPS showed significant differences in efficacy of treatment compared with placebo, especially for pain control, and also showed no differences in the rate of procedure-related adverse events.

Factors that influence the urodynamic results of botulinum toxin in the treatment of neurogenic hyperactivity

OBJECTIVES

To determine the urodynamic efficacy and factors that influence the urodynamic results of treatment of neurogenic detrusor hyperactivity with intradetrusor injection of botulinum toxin type A (BTX-A) in patients with spinal cord injury (SCI).

MATERIAL AND METHODS

A retrospective study was conducted with a cohort of 70 patients composed of 40 men and 30 women with stable SCI (mean age, 39 ± 13.3 years) who underwent an intradetrusor injection of 300 IUs of BTX-A. A urodynamic study was conducted prior to the injection and 6 ± 4.3 months after the treatment. New urodynamic studies were subsequently performed up to an interval of 16 ± 12.2 months.

RESULTS

The BTX-A significantly increased (p < .05) the cystomanometric bladder capacity, the bladder volume of the first involuntary contraction of the detrusor and the postvoid residue. We observed a decrease that tended towards statistical significance (p < .1) of the maximum detrusor pressure and the maximum urine flow. Neither the bladder accommodation nor the urethral resistance index (bladder outlet obstruction index) varied significantly. The increase in vesical capacity was maintained in 50% of the sample for more than 32 months. Age, sex, anticholinergic treatment and lesion age showed no influence in terms of the increase in bladder capacity. The indwelling urinary catheter (IUC) was the only statistically significant negative factor.

CONCLUSIONS

The urodynamic effect of BTX-A is maintained for a considerable time interval. The IUC negatively influences the result of the treatment.

[The role of urinary markers in the assessment and follow-up of lower urinary tract disorders: a literature review]

OBJECTIVES

To conduct a literature review on the role of urinary biomarkers in the initial assessment and follow-up of lower urinary tract symptoms.

METHODS

A literature review was conducted in August 2014 using the Medline/Pubmed database limiting the search to work in English or French.

RESULTS

Most studies were of level of evidence 2 or 3 (prospective cohort, controlled or not) and mainly about overactive bladder and bladder pain syndrome. Nerve Growth Factor (NGF) was the most studied and apparently the most promising in the evaluation of overactive bladder (OAB) and neurogenic detrusor overactivity (NDO). Urinary levels of ATP, prostaglandin E2 (PGE2), Brain-Derived Neurotrophic Factor (BDNF) and some cytokines were also significantly higher in most studies in patients with NDO or OAB. Epidermal Growth Factor (EGF), Heparin-Binding EGF (HBEGF) and Antiproliferative Factor (APF) were the most studied urinary markers in bladder pain syndrome, with a significant increase (EGF APF) or decrease (HBEGF) in cases of interstitial cystitis (compared to healthy controls). The urinary N-terminal-telopeptide (NTx) could be predictive of a failed mid-urethral sling. However, few studies reported the diagnostic values of the markers, their association with urodynamic parameters were rarely evaluated and the existence of a publication bias is likely. No randomized controlled study has so far compared the urinary markers to urodynamic evaluation.

CONCLUSION

In the future, urinary markers could complete or replace urodynamic examination. However, to date, there is no high level of evidence study comparing these markers to urodynamics and their use can therefore not be recommended in daily practice.