Botulinum-A toxin injections into the detrusor muscle decrease nerve growth factor bladder tissue levels in patients with neurogenic detrusor overactivity

Dramatic Effect of Botulinum Toxin Type A on Hypertrophic Scar: A Promising Therapeutic Drug and Its Mechanism Through the SP-NK1R Pathway in Cutaneous Neurogenic Inflammation

Background

Hypertrophic scar formation may be related to cutaneous neurogenic inflammation (CNI) through the substance P-neurokinin 1 receptor (SP-NK1R) signaling pathway. As a widely used drug in aesthetic clinical work, botulinum toxin type A (BTX-A) has a therapeutic effect on scars, but the actual mechanism remains unclear. This study aimed to clarify the potential mechanism by which BTX-A inhibits CNI in hypertrophic scars both in vitro and in vivo.

Methods

Tissue samples were obtained from surgical excisions. Immunohistological analysis was used to locate SP in human hypertrophic scars and normal skin. RT-PCR and western blot analysis were used to evaluate the expression of collagens after SP/BTX-A treatment. A rabbit ear scar model was used to explore the in vivo effect of BTX-A on scar treatment.

Results

SP and NK-1R were overexpressed in hypertrophic scars compared to normal skin tissues. Collagen secretion of hypertrophic scar-derived fibroblasts increased with increasing doses of SP. However, BTX-A may downregulate collagen expression through SP-NK1R pathway with or without the presence of SP inducing agent capsaicin. Meanwhile, SP inhibited the expression of NK-1R, and this inhibition was blocked by pretreatment with BTX-A. In vivo, intralesional BTX-A injection can also reduce the volume of scars and inhibit collagen secretion. Capsaicin may cause more severe scar manifestations, while the therapeutic effect of BTX-A remains.

Conclusion

Our research confirms that CNI stimulates fibroblasts during scar formation, while BTX-A can reduce collagen secretion by inhibiting the SP-NK1R signaling pathway, thus identifying a novel therapeutic target for this benign solid skin tumor.

The urothelium, the urinary microbioma and men LUTS: a systematic review

INTRODUCTION

The pathophysiology and management of male patients with lower urinary tract symptoms (LUTS) is still a matter of debate. In the past few years, the urothelium and the urinary microbiota represented important areas of research to improve the understanding and management of these patients. Aim of the present review was to summarize the available data on the urothelium and the microbiota related to male LUTS.

EVIDENCE ACQUISITION

A National Center for Biotechnology Information (NCBI) PubMed search for relevant articles published between January 2000 and December 2019 was performed using the medical subjects heading "urothelium," "microbioma," "microbiota," "urobioma," "urobiota," "benign prostatic hyperplasia," "benign prostatic enlargement," "lower urinary tract symptoms," "lower urinary tract dysfunction," "men," "male," "overactive bladder," "receptors." Exclusion criteria included: animal studies and studies on muscarinic and adrenergic pathways.

EVIDENCE SYNTHESIS

The urothelium has been recently evaluated in humans to evaluate new possible markers and pathways. New possible targets for the treatment of male LUTS include the neural growth factor, the cannabinoid, the vanilloid and the ATP pathways. However, studies in humans are still needed to elucidate the exact role of these pathways in the management of male patients with LUTS. The available evidence on the urinary microbioma in male is poor. Standing to the available, urinary microbioma is evident in healthy urine in males. Moreover, the urinary microbioma varies depending on the method of collection, sexually transmitted disease status, inflammation and urinary symptoms. A possible role of probiotics in the management of LUTS in women has been proposed and may have a role in male patients as well.

CONCLUSIONS

The urothelium and the urinary microbiota are still poorly studied in men with LUTS. Most of the evidence and the hypothesis on the relationship between urothelium/urinary microbiota and LUTS comes from animal/in-vitro evidence while clinical trials are lacking. These pathways seem interesting even in LUTS pathogenesis in men but their possible role as a new therapeutic target is still an open debate.

Biomarkers in Spinal Cord Injury: Prognostic Insights and Future Potentials

Spinal Cord Injury (SCI) is a major challenge in Neurotrauma research. Complex pathophysiological processes take place immediately after the injury and later on as the chronic injury develops. Moreover, SCI is usually accompanied by traumatic injuries because the most common modality of injury is road traffic accidents and falls. Patients develop significant permanent neurological deficits that depend on the extent and the location of the injury itself and in time they develop further neurological and body changes that may risk their mere survival. In our review, we explored the recent updates with regards to SCI biomarkers. We observed two methods that may lead to the appearance of biomarkers for SCI. First, during the first few weeks following the injury the Blood Spinal Cord Barrier (BSCB) disruption that releases several neurologic structure components from the injured tissue. These components find their way to Cerebrospinal Fluid (CSF) and the systemic circulation. Also, as the injury develops several components of the pathological process are expressed or released such as in neuroinflammation, apoptosis, reactive oxygen species, and excitotoxicity sequences. Therefore, there is a growing interest in examining any correlations between these components and the degrees or the outcomes of the injury. Additionally, some of the candidate biomarkers are theorized to track the progressive changes of SCI which offers an insight on the patients' prognoses, potential-treatments-outcomes assessment, and monitoring the progression of the complications of chronic SCI such as Pressure Ulcers and urinary dysfunction. An extensive literature review was performed covering literature, published in English, until February 2018 using the Medline/PubMed database. Experimental and human studies were included and titles, PMID, publication year, authors, biomarkers studies, the method of validation, relationship to SCI pathophysiology, and concluded correlation were reported. Potential SCI biomarkers need further validation using clinical studies. The selection of the appropriate biomarker group should be made based on the stage of the injuries, the accompanying trauma and with regards to any surgical, or medical interference that might have been done. Additionally, we suggest testing multiple biomarkers related to the several pathological changes coinciding to offer a more precise prediction of the outcome.

Investigational drugs for bladder pain syndrome (BPS) / interstitial cystitis (IC)

INTRODUCTION

Bladder pain syndrome (BPS)/interstitial cystitis (IC) is associated with sensory lower urinary tract symptoms. Unfortunately, many of the existing oral treatments are ineffective in most patients of BPS/IC, which is the motivation for developing new drugs and therapeutic approaches. This review covers the latest drugs that have been investigated in BPS/IC patients. Intravesical treatments offer the opportunity to directly target the painful bladder with less systemic side effects.

AREAS COVERED

In this review, the authors analyze the existing literature supporting the treatment of BPS/IC with conventional drugs including heparin, hyaluronic acid, chondroitin sulfate, and dimethylsulfoxide (DMSO). Furthermore, investigational drugs such as tanezumab and adalimumab, capable of sequestering nerve growth factor (NGF), and Tumor necrosis factor-α (TNF- α) are discussed. Investigational treatments such as liposomes, botulinum toxin (BTX), liposomal BTX, PD-0299685 (a Ca(2+) channel ɑ2δ ligand), continuous intravesical lidocaine, and AQX-1125 (a novel SHIP1 activating compound) are also covered.

EXPERT OPINION

New investigational drugs offer promising improvements in clinical outcomes for BPS/IC patients; however, BPS/IC is a chronic pain disorder that is very vulnerable to a strong placebo effect. In addition, BPS/IC is a heterogeneous disorder that can be classified into several phenotypes. Since different phenotypes of BPS/IC respond differently to systemic and intravesical treatments, the authors believe that new drugs developed for BPS/IC are more likely to meet their predetermined clinical endpoints if the inclusion/exclusion criterion is tailored to specific phenotype of BPS/IC patients.

Botulinum toxin A for the Treatment of Overactive Bladder

The standard treatment for overactive bladder starts with patient education and behavior therapies, followed by antimuscarinic agents. For patients with urgency urinary incontinence refractory to antimuscarinic therapy, currently both American Urological Association (AUA) and European Association of Urology (EAU) guidelines suggested that intravesical injection of botulinum toxin A should be offered. The mechanism of botulinum toxin A includes inhibition of vesicular release of neurotransmitters and the axonal expression of capsaicin and purinergic receptors in the suburothelium, as well as attenuation of central sensitization. Multiple randomized, placebo-controlled trials demonstrated that botulinum toxin A to be an effective treatment for patients with refractory idiopathic or neurogenic detrusor overactivity. The urinary incontinence episodes, maximum cystometric capacity, and maximum detrusor pressure were improved greater by botulinum toxin A compared to placebo. The adverse effects of botulinum toxin A, such as urinary retention and urinary tract infection, were primarily localized to the lower urinary tract. Therefore, botulinum toxin A offers an effective treatment option for patients with refractory overactive bladder.

Intravesical Botulinum Toxin for Persistent Autonomic Dysreflexia in a Pediatric Patient

Introduction. We present a novel case of persistent autonomic dysreflexia in a pediatric spinal cord injury patient treated successfully with intravesical botulinum toxin. Study Design. A retrospective chart review of one patient seen at the Children's Hospital of Wisconsin from 2006 to 2012 was performed. Results. A pediatric spinal cord injury patient with known neurogenic bladder presented with severe hypertension consistent with autonomic dysreflexia. His symptoms and hypertension did not improve with conservative measures, and he necessitated ICU admission and antihypertensive drips. He was taken to the operating room for intravesical botulinum toxin for refractory bladder spasms. Following this, his symptoms abated, and he was weaned off IV antihypertensives and returned to his baseline state. His symptoms were improved for greater than six months. Conclusions. There are few treatment options for the management of refractory autonomic dysreflexia. Intravesical botulinum toxin has never been reported for this use. Dedicated research is warranted to assess its efficacy, as it was used successfully to abort autonomic dysreflexia in this patient.

Effect of detrusor botulinum toxin a injection on urothelial dysfunction in patients with chronic spinal cord injury: a clinical and immunohistochemistry study before and after treatment

OBJECTIVE

The objective of this study is to investigate the changes of urothelial junction proteins, apoptosis and suburothelial inflammation after detrusor injection of botulinum toxin A (BoNT-A) in patients with spinal cord injury (SCI) and neurogenic detrusor overactivity (NDO).

METHODS

A total of 26 patients with chronic suprasacral SCI and NDO were enroled. The urothelium was assessed by cystoscopic biopsy at baseline, 3 and 6 months after a single treatment of 300 U BoNT-A into the detrusor. Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1) and tryptase for mast cell activity were performed. Urothelial apoptosis was also evaluated. The differences in urothelial dysfunction were compared between baseline and 3 and 6 months after treatment. Bladder biopsies from patients undergoing anti-incontinence surgery served as controls.

RESULTS

A single 300-U BoNT-A injection into the detrusor significantly decreased detrusor pressure and increased bladder compliance at 3 and 6 months after treatment. Significantly lower E-cadherin and ZO-1 expressions and increased mast cell and apoptotic cell counts were noted in SCI bladders compared with controls (all P<0.001). Significantly greater distributions of E-cadherin (P<0.001) and ZO-1 (P=0.05) expressions were noted 3 months after BoNT-A injection. However, these changes had declined by 6 months after treatment. Activated mast cells and urothelial apoptosis showed no significant differences between baseline and 3 or 6 months.

CONCLUSION

Urothelial dysfunction and adhesive and junction protein concentrations in SCI patients' bladders recovered after BoNT-A treatment. However, this effect decreased with time. Thus, neurogenic inflammation after SCI was not adequately improved after a single BoNT-A injection.

Potential Biomarkers Utilized to Define and Manage Overactive Bladder Syndrome

Clinical diagnosis of overactive bladder (OAB) syndrome has great variation and usually can only be based on subjective symptoms. Measurement of urgency severity score in adjunct with voiding diary may reflect the occurrence of OAB and incontinence severity in daily life. Urodynamic study can detect detrusor overactivity (DO), but not in all OAB patients. A more objective way and less invasive tool to diagnose and assess therapeutic outcome in OAB patients is needed. Recent investigations of the potential biomarkers for OAB include urinary and serum biomarkers and bladder wall thickness. Evidence has also shown that urinary proteins, such as nerve growth factor (NGF) and prostaglandin E2 (PGE2 ) levels increase in patients with OAB, bladder outlet obstruction (BOO) and DO. Patients with OAB have significantly higher urinary NGFlevels and urinary NGF levels decrease after antimuscarinic therapy and further decrease after detrusor botulinum toxin injections. However, the sensitivity of single urinary protein in the diagnosis of OAB is not high and several lower urinary tract diseases may also have elevated urinary NGF levels. Searching for a group of inflammatory biomarkers by microsphere-based array in urine might be a better method in differential diagnosis of OAB from interstitial cystitis, urinary tract infection (UTI) or urolithiasis. Bladder wall thickness has been widely investigated in the diagnosis of BOO and pediatric voiding dysfunction.The role of bladder wall thickness in the diagnosis of OAB, however, has not reach a consistent conclusion. We hereby review the latest medical advances in this field.

Does Reduction of Number of Intradetrusor Injection Sites of aboBoNTA (Dysport®) Impact Efficacy and Safety in a Rat Model of Neurogenic Detrusor Overactivity?

Intradetrusor injections of Botulinum toxin A—currently onabotulinumtoxinA—is registered as a second-line treatment to treat neurogenic detrusor overactivity (NDO). The common clinical practice is 30 × 1 mL injections in the detrusor; however, protocols remain variable and standardization is warranted. The effect of reducing the number of injection sites of Dysport^® abobotulinumtoxinA (aboBoNTA) was assessed in the spinal cord-injured rat (SCI). Nineteen days post-spinalization, female rats received intradetrusor injections of saline or aboBoNTA 22.5 U distributed among four or eight sites. Two days after injection, continuous cystometry was performed in conscious rats. Efficacy of aboBoNTA 22.5 U was assessed versus aggregated saline groups on clinically-relevant parameters: maximal pressure, bladder capacity, compliance, voiding efficiency, as well as amplitude, frequency, and volume threshold for nonvoiding contractions (NVC). AboBoNTA 22.5 U significantly decreased maximal pressure, without affecting voiding efficiency. Injected in four sites, aboBoNTA significantly increased bladder capacity and compliance while only the latter when in eight sites. AboBoNTA significantly reduced NVC frequency and amplitude. This preclinical investigation showed similar inhibiting effects of aboBoNTA despite the number of sites reduction. Further studies are warranted to optimize dosing schemes to improve the risk-benefit ratio of BoNTA-based treatment modalities for NDO and further idiopathic overactive bladder.

Botulinum toxin type A induces changes in the chemical coding of substance P-immunoreactive dorsal root ganglia sensory neurons supplying the porcine urinary bladder

Botulinum toxin (BTX) is a potent neurotoxin which blocks acetylcholine release from nerve terminals, and therefore leads to cessation of somatic motor and/or parasympathetic transmission. Recently it has been found that BTX also interferes with sensory transmission, thus, the present study was aimed at investigating the neurochemical characterization of substance P-immunoreactive (SP-IR) bladder-projecting sensory neurons (BPSN) after the toxin treatment. Investigated neurons were visualized with retrograde tracing method and their chemical profile was disclosed with double-labelling immunohistochemistry using antibodies against SP, calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase activating polypeptide (PACAP), neuronal nitric oxide synthase (nNOS), galanin (GAL), calbindin (CB), and somatostatin (SOM). In the control group (n = 6), 45% of the total population of BPSN were SP-IR. Nearly half of these neurons co-expressed PACAP or CGRP (45% and 35%, respectively), while co-localization of SP with GAL, nNOS, SOM or CB was found less frequently (3.7%, 1.8%, 1.2%, and 0.7%, respectively). In BTX-treated pigs (n = 6), toxin-injections caused a decrease in the number of SP-IR cells containing CGRP, SOM or CB (16.2%, 0.5%, and 0%, respectively) and a distinct increase in these nerve cells immunopositive to GAL (27.2%). The present study demonstrates that BTX significantly modifies the chemical phenotypes of SP-IR BPSN.

The effect of spinal cord-injury level on the outcome of neurogenic bladder treatment using OnabotulinumtoxinA

Aim:

The aim was to report the effectiveness and safety OnabotulinumtoxinA (Botox, Allergan, Inc., Irvine, CA, USA) intradetrusor injections in spinal cord-injured (SCI) patients with refractory neurogenic detrusor overactivity. And to assess the result based on SCI level.

Materials and Methods:

We reviewed the chart of 103 patients with neurogenic bladder secondary to SCI at the rehab center who received OnabotulinumtoxinA in our Neurourology Department for treatment of lower urinary tract symptoms between January 2007 and December 2013. All patients had a clinical examination, urinalysis, and an urodynamic study at baseline and 3 months after treatment as well as a visual analogue scale (VAS; range scale: 0–10) and a bladder diary checked for 3 days. 300 IU of OnabotulinumtoxinA, detrusor muscle injections were performed in 30 sites under cystoscopic guidance. Outcome measures included frequency of urge urinary incontinence collected by bladder diaries; changes in urodynamic parameters such as maximum cystometric bladder capacity, reflex volume, maximum detrusor pressure; side-effects; antimuscarinic drug consumption and quality of life (QOL) measured with VAS.

Results:

The study includes 32 female and 71 male with a mean patient age of 29 years (range: 18–56 year). The effect of Botox injection on bladder function was observed within 1–2 week after treatment. The urodynamic parameters were improved significantly after treatment compared with baseline values. There were significant reductions in the frequencies of incontinence episodes after treatment as seen in the voiding diary. A significant improvement in patient satisfaction was found after treatment which was expressed on the VAS assessment, with an improvement of the mean of 3 points. Patients with thoracic and lumbar injury have better result compare to cervical injury patients. The earliest recurrence of clinical symptoms was at 10 weeks. Overall, the mean duration of symptomatic improvement was 8 (2.5–21) months.

Conclusion:

Intradetrusor onabotulinumtoxinA injections are an effective and well-tolerated treatment for neurogenic overactive bladder that will increase patient satisfaction and improve QOL with persisted clinical efficacy for more than 8 months.

Biomarkers of spinal cord injury and ensuing bladder dysfunction

During the acute phase of SCI, the extension and residual neurological deficits that will persist after the waning of the spinal shock period are difficult to estimate on clinical grounds. Therefore, objective biomarkers able to estimate the extension of the lesion and the degree of neurological recovery are of great importance. Research has been focused on the detection of structural neuronal and glial proteins that leak from damaged cells, inflammatory proteins recruited to remove necrotic debris and more accurate neuroimaging methods that are able to discriminate the extension and functional consequences of the SCI. Urinary biomarkers are also being investigated to estimate functional changes that typically affect bladder function following SCI which can endanger patient's life in the long run. Future studies are needed to precisely characterize the composition and function of the glial scar that appears in the area of SCI and repeals axonal growth, therefore preventing axonal rewiring.

Intravesical injection of botulinum toxin A for treatment of interstitial cystitis/bladder pain syndrome: 10 years of experience at a single center in China

INTRODUCTION AND HYPOTHESIS

To evaluate the efficacy and safety of the intravesical injection of Chinese botulinum toxin A (BTX-A) in patients with interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

Between January 2003 and June 2013, 124 women with IC/BPS were studied. Of these 124 patients, 66 were treated with BTX-A and 58 underwent bladder hydrodistention plus sodium hyaluronate (Cystistat) instillation. Intravesical injection of 100 U of Chinese BTX-A was immediately followed by cystoscopic hydrodistention under intravenous general anesthesia. The patients were evaluated using the O'Leary-Saint score, a visual analog scale pain score, a urinary frequency record and a quality of life questionnaire before treatment and 1 week, and 1, 3, 6 and 12 months after treatment.

RESULTS

Of the patients who received BTX-A injection, only 2 had acute urinary retention, 23 received a repeat injection, and 20 were lost to follow-up. Of the patients treated with hydrodistention plus Cystistat instillation, 2 had urinary tract infection, 11 switched to BTX-A injection at 6 months, and 23 were lost to follow-up. BTX-A was shown to remain effective for up to 6 months after treatment. After repeated Chinese BTX-A injections, symptoms improved significantly. Hydrodistention plus Cystistat remained effective for up to 3 months after treatment.

CONCLUSIONS

Intravesical injection of Chinese BTX-A is a safe and effective therapeutic option for patients with IC/BPS. The average duration of the effect of one dose of Chinese BTX-A amongst the responders was 6 months. Repeated injection of Chinese BTX-A is safe and effective.

Neural control of the lower urinary tract

This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed.

Bladder instillation of liposome encapsulated onabotulinumtoxina improves overactive bladder symptoms: a prospective, multicenter, double-blind, randomized trial

PURPOSE

Cystoscopic intradetrusor injection of botulinum toxin has helped patients with refractory overactive bladder but with the increased risks of urinary tract infection and urinary retention. We assessed whether catheter instillation of 200 U onabotulinumtoxinA formulated with liposomes is safe and effective for the treatment of overactive bladder.

MATERIALS AND METHODS

This 2-center, double-blind, randomized, placebo controlled study enrolled patients with overactive bladder inadequately managed with antimuscarinics. Patients were assigned to intravesical instillation of lipo-botulinum toxin (31) or normal saline (31). The primary end point was the mean change in micturition events per 3 days at 4 weeks after treatment. Additional end points included mean changes in urgency events, frequency and urinary urge incontinence, as well as changes in overactive bladder symptom scores and urgency severity scores.

RESULTS

At 4 weeks after treatment lipo-botulinum toxin instillation was associated with a statistically significant decrease in micturition events per 3 days (-4.64 for lipo-botulinum toxin vs -0.19 for placebo, p = 0.0252). Lipo-botulinum toxin instillation was also associated with a statistically significant decrease in urinary urgency events with respect to baseline but not placebo. However, lipo-botulinum toxin instillation was associated with a statistically significant decrease in urgency severity scores compared to placebo (p = 0.0181). These observed benefits of lipo-botulinum toxin instillation were not accompanied by an increased risk of urinary retention. The effects of lipo-botulinum toxin on urinary urge incontinence were inconclusive.

CONCLUSIONS

A single intravesical instillation of lipo-botulinum toxin was associated with decreases in overactive bladder symptoms without side effects. Intravesical instillation of liposomal botulinum toxin may be a promising approach to treat refractory overactive bladder.

Neural mechanisms underlying lower urinary tract dysfunction

This article summarizes anatomical, neurophysiological, and pharmacological studies in humans and animals to provide insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract and alterations in these mechanisms in lower urinary tract dysfunction. The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the bladder, urethra, and external urethral sphincter. During urine storage, the outlet is closed and the bladder smooth muscle is quiescent. When bladder volume reaches the micturition threshold, activation of a micturition center in the dorsolateral pons (the pontine micturition center) induces a bladder contraction and a reciprocal relaxation of the urethra, leading to bladder emptying. During voiding, sacral parasympathetic (pelvic) nerves provide an excitatory input (cholinergic and purinergic) to the bladder and inhibitory input (nitrergic) to the urethra. These peripheral systems are integrated by excitatory and inhibitory regulation at the levels of the spinal cord and the brain. Therefore, injury or diseases of the nervous system, as well as disorders of the peripheral organs, can produce lower urinary tract dysfunction, leading to lower urinary tract symptoms, including both storage and voiding symptoms, and pelvic pain. Neuroplasticity underlying pathological changes in lower urinary tract function is discussed.

Efficacy and safety of botulinum toxin A intradetrusor injections in adults with neurogenic detrusor overactivity/neurogenic overactive bladder: a systematic review

BACKGROUND

Botulinum toxin A (BoNTA) is increasingly used for therapy of neurogenic detrusor overactivity (NDO) refractory to antimuscarinics or where patients are experiencing antimuscarinic-related side effects.

OBJECTIVE

The objective was to compare and critically discuss the reported efficacy and safety of BoNTA in adults with neurogenic bladder dysfunction.

DATA SOURCES

Studies published between January 1985 and July 2012 were identified in the MEDLINE (PubMed) and SCOPUS databases.

STUDY SELECTION, STUDY APPRAISAL AND SYNTHESIS METHODS

A search for studies with onabotulinumtoxinA--the only formulation of BoNTA approved by the US FDA in adults with NDO--was performed. Exclusion criteria were urethral sphincter injection, no separate analysis between onabotulinumtoxinA and other formulations of BoNTA, mean follow-up ≤ 4 weeks and studies with ten or fewer patients. Clinical and urodynamic parameters for efficacy, adverse events (AEs) and tolerability were reviewed to offer recommendations for practice and future research.

RESULTS

A total of 28 included studies revealed superior effects of onabotulinumtoxinA compared with placebo in achieving continence, reducing incontinence episodes, improving urodynamic parameters and health-related quality of life. The most frequently reported AEs were de novo intermittent catheterization, urinary retention and asymptomatic urinary infection.

LIMITATIONS

Limitations of this review are the inclusion of studies with the level-3 evidence (22/28 studies), the heterogenicity of outcome parameters and time points chosen for follow-up reported in the reviewed studies.

CONCLUSIONS

OnabotulinumtoxinA therapy is effective, safe and well tolerated in adults with neurogenic bladder dysfunction. Further high-quality prospective trial data are required to determine the optimal dose, injection technique, long-term safety, favourable timing, indications for re-injections, and the impact of concomitant antimuscarinics on onabotulinumtoxinA therapy.

Repeated intravesical onabotulinumtoxinA injections are effective in treatment of refractory interstitial cystitis/bladder pain syndrome

AIMS

To evaluate the efficacy and safety of repeated intravesical onabotulinumtoxinA (BoNT-A) injections for treatment of interstitial cystitis/bladder pain syndrome (IC/BPS).

PATIENTS AND METHODS

Patients confirmed to have IC/BPS and refractory to conventional treatments were treated with intravesical injections of 100 U of BoNT-A plus hydrodistention every 6 months for up to four times. Primary end-point was 6 months after the fourth BoNT-A injection. Measured parameters included O'Leary-Sant symptom score (OSS) including symptom and problem indexes (ICSI/ICPI), visual analogue score (VAS) for pain, voiding diary variables, urodynamic parameters, maximal bladder capacity (MBC), glomerulation grade, and global response assessment (GRA). Multiple measurements and Wilcoxon rank-sum test were used for comparison between groups.

RESULTS

In overall patients, GRA, OSS, ICSI and ICPI scores, VAS, functional bladder capacity (FBC) and cystometric bladder capacity (CBC) all showed significant improvement. The glomerulation grade decreased (1.77 ± 1.06 vs. 1.19 ± 1.05, p = 0.026), but MBC remained unchanged. Among 31 patients, 19 (61%) had a GRA ≥ 2 and 12 (39%) had a GRA < 2 at end-point. Patients with a GRA ≥ 2 had significantly greater changes in OSS, ICPI, VAS, FBC and CBC than patients with a GRA < 2. Extended study revealed that persistent symptomatic improvement lasted 6-12 months in seven, 13-22 months in six and 23-51 months in six after the fourth BoNT-A injection. Five women who had GRA < 2 were found to have Hunner's ulcer. Lack of control is the main limitation.

CONCLUSION

Four repeated intravesical BoNT-A injections were safe and effective for symptom and pain relief and increased bladder capacity for treatment of IC/BPS.

Nerve growth factor (NGF): a potential urinary biomarker for overactive bladder syndrome (OAB)?

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The search for a biomarker in overactive bladder syndrome (OAB) is an emerging field of interest, as bladder dysfunction is a common complaint that causes significant morbidity. A biomarker may give us insight as a diagnostic tool, and also inform us about how severe the condition is, how it may progress and how it may best be treated. The protein of interest here is nerve growth factor (NGF) and it has been shown to be a dynamic molecule in the bladder of patients with OAB. Urinary levels have been seen to rise in patients with OAB and fall in those who respond to treatment. However, there have also been many studies that examine this trend in numerous other conditions, e.g. interstitial cystitis, bladder outflow obstruction, renal stone disease and patients with neurological impairment after stroke. As a result the specificity of this as a potential urinary biomarker for OAB is questioned. This is a review of published studies, which discusses the pros and cons of NGF as a potential urinary biomarker. The evidence is examined and the studies are summarised together in a Table. Questions remain about the reliability, practicality and specificity of NGF as a biomarker for OAB. These questions need to be addressed by further studies that could clarify the points raised.

OBJECTIVE

To review the current literature on the use of urinary nerve growth factor (NGF) as a potential biomarker for overactive bladder syndrome (OAB).

METHOD

A comprehensive electronic literature search was conducted using the PubMed database to identify publications relating to urinary NGF.

RESULTS

There are a growing number of publications that have measured urinary NGF levels in different types of bladder dysfunction. These range from OAB, bladder pain syndrome, idiopathic and neurogenic detrusor overactivity, bladder oversensitivity and bladder outflow obstruction. Urinary NGF levels do appear to be raised in these pathological states when compared with healthy control samples. In patients with OAB, these raised urinary NGF levels appear to also reduce after successful treatment with antimuscarinics and botulinum toxin A, which indicates a potential use in monitoring responses to treatment. However, raised levels are not limited to OAB, which questions its specificity. Urinary NGF measurements are performed with an enzyme-linked immunosorbent assay using polyclonal antibodies to NGF. The technique requires standardisation, and the different antibodies to NGF require validating. Also a definition of what is the 'normal' range of NGF in urine is still required before it can be used as a diagnostic and prognostic tool.

CONCLUSIONS

Whilst the evidence for an increased urinary NGF in OAB appears convincing, many questions about its validity remain including: specificity, sensitivity, cost- and time-effectiveness. Many criteria for what constitutes a biomarker still need to be evaluated and met before this molecule can be considered for this role.

Highlights in basic autonomic neuroscience: contribution of the urothelium to sensory mechanisms in the urinary bladder

Urothelial cells in the urinary bladder express neural properties including: (1) release of neurotransmitters and neurotrophic factors, (2) expression of neurotransmitter receptors and ion channels, and (3) sensitivity to mechanical and chemical stimuli. These properties have focused attention on the possible contribution of the urothelium to the storage and emptying functions of the bladder. In addition chemicals released from urothelial cells can affect the excitability of adjacent afferent nerves and this interaction can be affected by pathological conditions. This raises the possibility that abnormal urothelial-afferent interactions may contribute to bladder dysfunctions and therefore be a target for drug therapy.

Urothelial signaling

The urothelium, which lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, not only forms a high-resistance barrier to ion, solute and water flux, and pathogens, but also functions as an integral part of a sensory web which receives, amplifies, and transmits information about its external milieu. Urothelial cells have the ability to sense changes in their extracellular environment, and respond to chemical, mechanical and thermal stimuli by releasing various factors such as ATP, nitric oxide, and acetylcholine. They express a variety of receptors and ion channels, including P2X3 purinergic receptors, nicotinic and muscarinic receptors, and TRP channels, which all have been implicated in urothelial-neuronal interactions, and involved in signals that via components in the underlying lamina propria, such as interstitial cells, can be amplified and conveyed to nerves, detrusor muscle cells, and ultimately the central nervous system. The specialized anatomy of the urothelium and underlying structures, and the possible communication mechanisms from urothelial cells to various cell types within the bladder wall are described. Changes in the urothelium/lamina propria ("mucosa") produced by different bladder disorders are discussed, as well as the mucosa as a target for therapeutic interventions.

Development and validation of the actionable bladder symptom screening tool for multiple sclerosis patients

Bladder symptoms such as urinary urgency, frequency, and incontinence are common in people with multiple sclerosis (MS). These symptoms, which often result from neurogenic detrusor overactivity (NDO), can have a major impact on patients' day-to-day lives. However, in many cases they are over-looked in the clinical management of MS. The objective of this study was to develop and validate a reliable, sensitive, and specific screening tool for patients with bladder problems related to MS. We performed a literature review and then conducted a content validation study followed by a multisite observational study of a new screening tool, the Actionable Bladder Symptom Screening Tool (ABSST). All ABSST domains as well as the total score met the threshold for good internal consistency (Cronbach α ≥ 0.70), with a Cronbach α value of 0.95 for the total score and values ranging from 0.85 to 0.90 for the three domains. The validity of the ABSST was demonstrated by high correlation of the domains and total score with the Overactive Bladder Questionnaire Short Form (OAB-q SF) Symptom Severity and Total Health-Related Quality of Life (HRQOL) scores (Spearman correlation coefficient ≥ 0.782). The predictive validity of the ABSST total score to identify patients who might receive a recommendation to see a urologist was strong. This new instrument, which was developed with input from clinicians as well as MS patients, meets the current content validity and psychometric testing thresholds established by the US Food and Drug Administration, with high sensitivity and specificity.

Onabotulinumtoxin-A intradetrusorial injections modulate bladder expression of NGF, TrkA, p75 and TRPV1 in patients with detrusor overactivity

How onabotulinumtoxinA (onab/A) injected in the detrusor muscle improves detrusor overactivity (DO) is still a matter of debate. Nerve growth factor (NGF) seems to play a role in determining urgency and DO. Recent studies showed that NGF decreases in patients with DO who respond to onab/A treatment. We investigated onab/A-induced changes on gene expression of NGF, TRPV1, TrkA and p75 in bladder wall tissue of patients affected by neurogenic and idiopathic DO. Twenty-five patients (18 with neurogenic DO and 7 with idiopathic DO) received onab/A injections into the detrusor muscle. Urodynamic studies and cystoscopies with sampling of the bladder wall were performed before and 1 month after onab/A injections. Onab/A-induced changes in urodynamic variables (first volume and maximum pressure of uninhibited detrusor contractions and maximum cystometric capacity) and NGF, TRPV1, TRKA, p75 gene expression by means of quantitative Real Time-Polymerase Chain Reaction. NGF protein levels were assessed in tissue homogenates by enzyme-linked immunosorbent assay. Onab/A significantly improved urodynamic findings (as shown by the increase in maximum cystometric capacity), decreased the bladder tissue levels of NGF protein and significantly increased NGF, TrkA, p75 and TRPV1 gene expression independently from the etiology of DO. No significant correlation has been found between NGF down-regulation and the increase in MCC. Correlations between NGF gene expression and NGF receptors' gene expression were influenced by onab/A dosages. In the short time follow-up, onab/A decreases NGF protein levels and increases NGF and associated receptors' gene expression possibly by inhibiting NGF release. Further studies with longer follow-up will clarify time course of onab/A-induced modifications in NGF expression.

Neurotrophins in the lower urinary tract: becoming of age

The lower urinary tract (LUT) comprises a storage unit, the urinary bladder, and an outlet, the urethra. The coordination between the two structures is tightly controlled by the nervous system and, therefore, LUT function is highly susceptible to injuries to the neuronal pathways involved in micturition control. These injuries may include lesions to the spinal cord or to nerve fibres and result in micturition dysfunction. A common trait of micturition pathologies, irrespective of its origin, is an upregulation in synthesis and secretion of neurotrophins, most notably Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF). These neurotrophins are produced by neuronal and non-neuronal cells and exert their effects upon binding to their high-affinity receptors abundantly expressed in the neuronal circuits regulating LUT function. In addition, NGF and BDNF are present in detectable amounts in the urine of patients suffering from various LUT pathologies, suggesting that analysis of urinary NGF and BDNF may serve as likely biomarkers to be studied in tandem with other factors when diagnosing patients. Studies with experimental models of bladder dysfunction using antagonists of NGF and BDNF receptors as well as scavenging agents suggest that those NTs may be key elements in the pathophysiology of bladder dysfunctions. In addition, available data indicates that NGF and BDNF might constitute future targets for designing new drugs for better treatment of bladder dysfunction.

Botulinum toxin injection for lower urinary tract dysfunction

Botulinum toxin has been recently accepted as a novel treatment for lower urinary tract dysfunctions refractory to conventional treatment. Review of the clinical trials in recent years, botulinum toxin type A has been widely used in the urethra or urinary bladder to treat voiding dysfunction due to detrusor sphincter dyssynergia, incontinence due to neurogenic or idiopathic detrusor overactivity, sensory disorders such as bladder hypersensitivity, overactive bladder, and interstitial cystitis/painful bladder syndrome. Intravesical botulinum toxin type A injection is effective in treatment of urinary incontinence due to detrusor overactivity in men and women, as well as in children. Currently botulinum toxin type A has also been applied to treat lower urinary tract symptoms due to benign prostatic hyperplasia in patients not suitable for surgery. This article reviewed the recent advances of botulinum toxin type A on lower urinary tract dysfunction.

Botulinum toxin A modulates afferent fibers in neurogenic detrusor overactivity

BACKGROUND

  Although botulinum toxin (BoNT/A) injected into the detrusor muscle improves overactive bladder symptoms in patients with neurogenic detrusor overactivity, how it does so remains unclear. In this study, we investigated whether BoNT/A improves detrusor overactivity by modulating bladder afferent activity.

METHODS

  To do so, during urodynamic assessment, we tested the soleus muscle Hoffmann (H) reflex during bladder filling before and after intradetrusor BoNT/A in patients with Parkinson's disease (PD) and in patients with complete chronic spinal cord lesion (SCI) and detrusor overactivity refractory to conventional therapy. Healthy subjects underwent H reflex studies during urodynamic assessment and acted as controls.

RESULTS

  Our findings show that BoNT/A injected into the detrusor muscle effectively reduces clinical overactive bladder symptoms in patients with PD and SCI. In healthy subjects and patients with PD, bladder filling [at maximum cystometric capacity, (MCC)] significantly decreased the H reflex size, whereas in patients with SCI, it slightly facilitated the H reflex size. At MCC, in patients with PD, BoNT/A significantly reduced the expected H reflex inhibition, whereas in those with SCI, BoNT/A turned the H reflex facilitation at maximum bladder filling into a slight inhibition.

CONCLUSIONS

  These findings show that BoNT/A injected into the detrusor muscle in patients with PD and SCI modulates bladder afferent activity. Modulation of bladder afferents possibly explains why BoNT/A improves detrusor overactivity.

[Value of nerve growth factor levels in overactive bladder syndrome: alterations after botulinum toxin therapy]

OBJECTIVES

Several studies discussing the pathology of overactive bladder suggested changes in urinary proteins. The neurotrophin "nerve growth factor" (NGF) seems to be an important marker in overactive bladder syndrome (OAB). In this prospectively designed study we evaluated NGF blood levels (sNGF) initially and after injection of botulinum toxin type A (BTX-A) in the detrusor muscle in patients suffering from idiopathic OAB.

MATERIALS AND METHODS

Blood samples were obtained from 26 patients (66.5 years, 28-83) with idiopathic OAB. sNGF levels were measured before and 4 weeks after BTX-A treatment by enzyme-linked immunosorbent assay (ELISA). A group of 32 healthy persons with normal bladder function served as controls (41 years, 19-60). sNGF was evaluated in relation to clinical data and the severity of OAB (wet/dry).

RESULTS

Significantly higher sNGF levels were detected in patients with OAB compared to the control group (58.8 vs 2.0 pg/ml, p<0.005). Further, sNGF levels were elevated in patients with wet OAB compared to patients with dry OAB (85.0 vs 0.73 pg/ml, p<0.005). Patients > 60 years showed significantly higher sNGF levels (77.2 vs 8.9 pg/ml, p<0.05) compared to younger OAB patients. After BTX-A therapy sNGF levels decreased significantly compared to baseline (p<0.005).

CONCLUSION

NGF appears to play a decisive role in OAB. Its use as a biomarker in both the diagnostics and follow-up after therapy seems promising. To what extent sNGF can be useful as a biomarker or in therapy monitoring needs to be examined prospectively in a larger population.

Effects of 100 and 300 units of onabotulinum toxin A on lower urinary tract symptoms of benign prostatic hyperplasia: a phase II randomized clinical trial

PURPOSE

We conducted a 2-stage, multicenter, double-blind, randomized phase II clinical trial of 100 and 300 unit doses of onabotulinum toxin A to treat the lower urinary tract symptoms of benign prostatic hyperplasia.

MATERIALS AND METHODS

Men 50 years old or older with clinically diagnosed benign prostatic hyperplasia, American Urological Association symptom index 8 or greater, maximum urinary flow rate less than 15 ml per second, voided volume 125 ml or greater, and post-void residual 350 ml or less were randomized to prostatic transrectal injection of 100 or 300 units of onabotulinum toxin A. The primary outcome was at least 30% improvement from baseline to 3 months in American Urological Association symptom index and/or maximum urinary flow rate and safety. The men were followed for 12 months.

RESULTS

A total of 134 men were randomized and treated (68 with 100 units, 66 with 300 units), with 131 assessed at 3 months and 108 assessed at 12 months. Each dose met the 3-month primary outcome criteria. In the 100 unit arm the mean baseline American Urological Association symptom index of 18.8 decreased by 7.1 and 6.9 at 3 and 12 months, respectively. In the 300 unit arm the baseline of 19.5 decreased by 8.9 and 7.1, respectively. In the 100 unit arm the mean baseline maximum urinary flow rate of 10.0 ml per second increased by 2.5 and 2.2, respectively, and in the 300 unit arm the baseline of 9.6 increased by 2.6 and 2.3, respectively.

CONCLUSIONS

The intraprostatic injection of 100 or 300 units of onabotulinum toxin A passed predetermined criteria for treatment efficacy and safety, and a randomized trial with either dose is warranted. The 100 unit dose may be preferable due to similar efficacy with reduced costs and adverse effects.

Effect of botulinum toxin on expression of nerve growth factor and transient receptor potential vanilloid 1 in urothelium and detrusor muscle of rats with bladder outlet obstruction-induced detrusor overactivity

OBJECTIVE

To investigate the effects of botulinum toxin A (BoNT/A) on the expression of nerve growth factor (NGF) and transient receptor potential vanilloid 1 (TRPV1) in the urothelium and detrusor muscle of rats with partial bladder outlet obstruction (BOO)-induced detrusor overactivity.

METHODS

Male Sprague-Dawley rats were allocated to a control group, a BOO group, or a BoNT/A-treated BOO group. BoNT/A (1 U) was injected into the detrusor muscle simultaneously with the induction of BOO. The rats were assessed by cystometrography 3 weeks later. The bladder was then removed. Immunofluorescence staining and Western blotting was performed to localize and quantify the expression of NGF and TRPV1 in the urothelium and detrusor muscle.

RESULTS

Cystometrography revealed induction of an unstable bladder in the BOO group and recovery of bladder stability after BoNT/A treatment. Expression of the NGF and TRPV1 proteins in the urothelium was significantly greater in the BOO group than in the control group and had decreased significantly with BoNT/A treatment in BOO-induced rat. The expression of NGF in detrusor muscle was significantly greater in the BOO group than in the control group and subsequently decreased significantly with BoNT/A treatment in the BOO-induced rat. In contrast, TRPV1 expression in the detrusor muscle did not differ significantly among the 3 groups.

CONCLUSION

Our experiments showed that detrusor wall injection of BoNT/A can modulate the expression of NGF and TRPV1, particularly in the urothelium, in accordance with recovery of bladder function.

Treatment of frozen shoulder with intra-articular injection of botulinum toxin in shoulder joints

Frozen shoulder, or adhesive capsulitis, is a disease of chronic inflammation and fibrosis involving the shoulder joints. The disease is challenging in clinical practice due to painful treatment course, with disease evolution usually lasting weeks or even months, causing significant discomfort and functional loss. Botulinum toxin (BTX) has been discovered to possess abilities in pain management at various clinical diseases. The actual mechanism is still under investigation, and involves inhibition of neurotransmitter release. In addition, BTX is also found to retard process of fibrosis, which is also a key issue in pathogenesis of frozen shoulder. Therefore, we hypothesize that intra-articular injection of BTX can be an effective alternative for treatment of frozen shoulder.