CHANGES IN BRAIN ACTIVITY FOLLOWING SACRAL NEUROMODULATION FOR URINARY RETENTION

Videourodynamics - role, benefits and optimal practice

Videourodynamics (VUDS) is an advanced diagnostic procedure that simultaneously combines functional and anatomical evaluation of the lower urinary tract. The goal of this synchronous assessment is to promote accurate diagnosis of the aetiology responsible for patient symptoms, improving therapeutic decision-making. Overall, high-quality VUDS is advocated when other tests such as traditional urodynamics might not provide sufficient data to guide therapy, particularly in patients with complex, persistent or recurrent dysfunctions of the lower urinary tract. Additionally, VUDS is often crucial in the follow-up monitoring of many patients with these dysfunctions. A VUDS study is frequently considered a gold standard in patients with neurogenic lower urinary tract dysfunction, female bladder outlet obstruction or congenital anomalies of the lower urinary tract. Nevertheless, this specialized test should be limited to patients in whom VUDS data add value. Particularly, reliable studies comparing the effect of diagnosis with and without imaging on management outcomes are lacking, and no standardized procedures for undertaking VUDS are available. Additionally, patients should be carefully selected for VUDS evaluation, considering the increased cost and risks associated with radiological imaging. In routine practice, clinicians should balance the additional value of synchronous imaging and the enhanced diagnostic precision of VUDS against the limitations of this approach, which mainly include an uncertain effect of VUDS on final treatment outcomes.

[Neurogenic lower urinary tract dysfunction following spinal cord injury]

A spinal cord injury (SCI) leads to neurogenic lower urinary tract dysfunction (NLUTD), which, if left untreated, can result not only in urinary incontinence and an increased risk of urinary tract infections and kidney dysfunction but may also pose a vital threat to people with SCI. Comprehensive neurourological assessments, including patient history and combined video urodynamics, are essential to accurately classify dysfunction and establish therapeutic strategies. Treatment options include, among others, medications for detrusor regulation, intermittent catheterization, and, if necessary, surgical interventions from intradetrusor botulinum toxin A injections to sacral deafferentation. An interdisciplinary approach and lifelong follow-up care are crucial for enhancing patients' quality of life and minimizing the risk of urological complications.

Bladder outlet obstruction in women: Scope of the problem and differential diagnosis

INTRODUCTION

The prevalence, formal definition, and diagnostic criteria of bladder outlet obstruction in owmen have not been clearly defined.

METHODS

This is a literature review of the definition of BOO in women, its prevalence, as well as its differential diagnosis.

RESULTS

The main causes of BOO in women are divided into functional and anatomic conditions. Functional etiologies include detrusor external sphincter dyssynergia, dysfunctional voiding, Fowler's syndrome, and primary bladder neck obstruction. Anatomic causes can be further divided into extrinsinc and intrinsic conditions. Intrinsic etiologies include urethral stricture and urethral diverticula, whereas extrinsic causes comprise pelvic organ prolapse, post anti-incontinence surgery, and Skene's gland cyst or abscess.

CONCLUSIONS

There are multiple etiologies to BOO in women, and this condition is most probably underdiagnosed, owing to a lack of consensus for a standard definition.

Long-term Outcomes of Periurethral Sphincter Botulinum Toxin in Female Chronic Urinary Retention

PURPOSE

Nonneurogenic chronic urinary retention is an uncommon problem in young female individuals, and a well characterised causes is Fowler syndrome (primary disorder of urethral sphincter relaxation). Intermittent catheterisation is often challenging, and gold standard treatment sacral neuromodulation is not widely available. Urethral sphincter botulinum toxin injection has been shown to be effective cross-sectionally, however little is known about long-term outcomes.

METHODS

Female individuals presenting with urinary retention due to Fowler syndrome were reviewed retrospectively from a single tertiary referral centre over an 11-year period (2010-2021). One hundred units of onabotulinum toxin A (BoTX-A) was injected into the striated urethral sphincter in a divided dose by the periurethral approach. Efficacy and side effects were assessed 4 weeks after injection.

RESULTS

Thirty-three female individuals with a mean age of 40.1±14.1 years received 165 unique urethral sphincter BoTX-A injections over 11 years. Nineteen individuals (57.6%) presented in acute urinary retention, and 28 (84.8%) were reliant on catheterisation. Twenty-one individuals (64%) responded to BoTX-A injections and had a significantly raised baseline maximum urethral closure pressure (MUCP), compared to nonresponders (114.6 cm H2O, P=0.012). Side effects were reported following 19 injections (11.5%) however, were mild and transient. Fifteen individuals received more than 1 botulinum toxin injection (median, 3 injections), with a median interval of 112 days (interquartile range) and efficacy persisted following repeat injections and no safety concerns were seen.

CONCLUSION

Sphincter botulinum toxin through the periurethral approach is safe and effective following repeat injections, and offers a low-cost, minimally invasive alternative to managing female chronic urinary retention due to Fowler syndrome, particularly when there was a high baseline MUCP.

[Neurogenic, non-obstructive urinary retention: diagnosis and treatment]

Neurogenic, non-obstructive urinary retention has a varied aetiology. The condition can be caused by central-nervous diseases as well as by disorders of the peripheral nervous system. The formation of residual urine may lead to considerable problems that can have a significant impact on a patient's everyday life. A treatment appropriate for the lower urinary tract dysfunction and suited to the patient's situation in life is only possible if a differentiated diagnostic evaluation has been performed. Both conservative and surgical therapeutic strategies are available, while drug treatment approaches are less relevant. Neuromodulative procedures are particularly suitable for causal treatment of the dysfunction. For patients requiring artificial bladder voiding, intermittent self-catheterization is generally preferable to using an indwelling catheter.

A Treatment Algorithm for High-Tone Pelvic Floor Dysfunction

OBJECTIVE

To develop evidence- and consensus-based clinical practice guidelines for management of high-tone pelvic floor dysfunction (HTPFD). High-tone pelvic floor dysfunction is a neuromuscular disorder of the pelvic floor characterized by non-relaxing pelvic floor muscles, resulting in lower urinary tract and defecatory symptoms, sexual dysfunction, and pelvic pain. Despite affecting 80% of women with chronic pelvic pain, there are no uniformly accepted guidelines to direct the management of these patients.

METHODS

A Delphi method of consensus development was used, comprising three survey rounds administered anonymously via web-based platform (Qualtrics XM) to national experts in the field of HTPFD recruited through targeted invitation between September and December 2021. Eleven experts participated with backgrounds in urology, urogynecology, minimally invasive gynecology, and pelvic floor physical therapy (PFPT) participated. Panelists were asked to rate their agreement with rated evidence-based statements regarding HTPFD treatment. Statements reaching consensus were used to generate a consensus treatment algorithm.

RESULTS

A total of 31 statements were reviewed by group members at the first Delphi round with 10 statements reaching consensus. 28 statements were reposed in the second round with 17 reaching consensus. The putative algorithm met clinical consensus in the third round. There was universal agreement for PFPT as first-line treatment for HTPFD. If satisfactory symptom improvement is reached with PFPT, the patient can be discharged with a home exercise program. If no improvement after PFPT, second-line options include trigger or tender point injections, vaginal muscle relaxants, and cognitive behavioral therapy, all of which can also be used in conjunction with PFPT. Onabotulinumtoxin A injections should be used as third line with symptom assessment after 2-4 weeks. There was universal agreement that sacral neuromodulation is fourth-line intervention. The largest identified barrier to care for these patients is access to PFPT. For patients who cannot access PFPT, experts recommend at-home, guided pelvic floor relaxation, self-massage with vaginal wands, and virtual PFPT visits.

CONCLUSION

A stepwise approach to the treatment of HTPFD is recommended, with patients often necessitating multiple lines of treatment either sequentially or in conjunction. However, PFPT should be offered first line.

Transcutaneous Electrical Stimulation of the Abdomen, Ear, and Tibial Nerve Modulates Bladder Contraction in a Rat Detrusor Overactivity Model: A Pilot Study

PURPOSE

The global prevalence of overactive bladder (OAB) is estimated at 11.8%. Despite existing treatment options such as sacral neuromodulation, a substantial number of patients remain untreated. One potential alternative is noninvasive transcutaneous electrical stimulation. This form of stimulation does not necessitate the implantation of an electrode, thereby eliminating the need for highly skilled surgeons, expensive implantable devices, or regular hospital visits. We hypothesized that alternative neural pathways can impact bladder contraction.

METHODS

In this pilot study, we conducted transcutaneous electrical stimulation of the abdominal wall (T6-L1), the ear (vagus nerve), and the ankle (tibial nerve) of 3 anesthetized female Sprague-Dawley rats. Stimulation was administered within a range of 20 Hz to 20 kHz, and its impact on intravesical pressure was measured. We focused on 3 primary outcomes related to intravesical pressure: (1) the pressure change from the onset of a contraction to its peak, (2) the average duration of contraction, and (3) the number of contractions within a specified timeframe. These measurements were taken while the bladder was filled with either saline or acetic acid (serving as a model for OAB).

RESULTS

Transcutaneous stimulation of the abdominal wall, ear, and ankle at a frequency of 20 Hz decreased the number of bladder contractions during infusion with acetic acid. As revealed by a comparison of various stimulation frequencies of the tibial nerve during bladder infusion with acetic acid, the duration of contraction was significantly shorter during stimulation at 1 kHz and 3 kHz relative to stimulation at 20 Hz (P = 0.025 and P = 0.044, respectively).

CONCLUSION

The application of transcutaneous electrical stimulation to the abdominal wall, ear, and tibial nerve could provide less invasive and more cost-effective treatment options for OAB relative to percutaneous tibial nerve stimulation and sacral neuromodulation. A follow-up study involving a larger sample size is recommended.

Sensory brain activation during rectal balloon distention: a pilot study in healthy volunteers to assess safety and feasibility at 1.5T

OBJECTIVE

Although increasing evidence suggests a central mechanism of action for sacral neuromodulation, the exact mechanism remains unclear. We set up a scanning paradigm to measure brain activation related to various stages of rectal filling using rectal balloon distention.

MATERIALS AND METHODS

Six healthy volunteers underwent rectal balloon distention during MRI scanning at a 1.5T scanner with a Tx/Rx head coil. MR images were collected at four levels of distention: empty balloon (EB), first sensation volume (FSV), desire to defecate volume (DDV), maximum tolerable volume (MTV). Data were analyzed using BrainVoyager 20.4. Whole brain and ROI-based fixed-effects general linear model analyses were performed on the fMRI time-course data from all participants.

RESULTS

Rectal filling until FSV evoked the most blood-oxygen-level-dependent responses in several clusters throughout the cortex, followed by the responses evoked by rectal filling until DDV. Interestingly, rectal filling until MTV evoked negative responses compared to baseline throughout the cortex. No negative side effects were found.

DISCUSSION

This study shows that a standardized paradigm for functional MRI combined with rectal filling is feasible and safe in healthy volunteers and is ready to be used in fecal incontinent patients to assess whether their brain activity differs from healthy controls.

Video-urodynamics efficacy of sacral neuromodulation for neurogenic bladder guided by three-dimensional imaging CT and C-arm fluoroscopy: a single-center prospective study

To assess the efficacy of sacral neuromodulation (SNM) for neurogenic bladder (NB), guided by intraoperative three-dimensional imaging of sacral computed tomography (CT) and mobile C-arm fluoroscopy through video-urodynamics examination. We enrolled 52 patients with NB who underwent conservative treatment with poor results between September 2019 and June 2021 and prospectively underwent SNM guided by intraoperative three-dimensional imaging of sacral CT and mobile C-arm fluoroscopy. Video-urodynamics examination, voiding diary, quality of life questionnaire, overactive bladder symptom scale (OABSS) scoring, and bowel dysfunction exam were completed and recorded at baseline, at SNM testing, and at 6-month follow-up phases. Finally, we calculated the conversion rate from period I to period II, as well as the treatment efficiency and the occurrence of adverse events during the testing and follow-up phases. The testing phase of 52 NB patients was 18–60 days, with an average of (29.3 ± 8.0) days. Overall, 38 patients underwent SNM permanent electrode implantation, whose follow-up phase was 3–25 months, with an average of (11.9 ± 6.1) months. Compared with baseline, the voiding times, daily catheterization volume, quality of life score, OABSS score, bowel dysfunction score, maximum detrusor pressure before voiding, and residual urine volume decreased significantly in the testing phase. The daily voiding volume, functional bladder capacity, maximum urine flow rate, bladder compliance, and maximum cystometric capacity increased significantly in the testing phase. Besides, the voiding times, daily catheterization volume, quality of life score, OABSS score, bowel dysfunction score, maximum detrusor pressure before voiding, and residual urine volume decreased further from the testing to follow-up phase. Daily voiding volume, functional bladder capacity, maximum urine flow rate, bladder compliance, and maximum cystometric capacity increased further from testing to follow-up. At baseline, 10 ureteral units had vesicoureteral reflux (VUR), and 9 of them improved in the testing phase. Besides, there was 1 unit that further improved to no reflux during the follow-up phase. At baseline, 10 patients had detrusor overactivity (DO), and 8 of them improved in the testing phase. Besides, 1 patient’s symptoms further improved during the follow-up phase. At baseline, there were 35 patients with detrusor-bladder neck dyssynergia (DBND); 14 (40.0%) of them disappeared during the testing phase. Among 13 cases who had DBND in the testing phase, 6 (46.2%) disappeared during the follow-up phase. Of the 47 patients with detrusor-external sphincter dyssynergia (DESD) at baseline, 8 (17.0%) disappeared during the testing phase. Among 26 cases who had DESD in the testing phase, 6 (23.1%) disappeared during the follow-up phase. The effective rate of this study was 88.5% (46/52), and the conversion rate from phase I to phase II was 73.1% (38/52). Additionally, the efficacy in a short-term follow-up was stable. SNM guided by intraoperative three-dimensional imaging of sacral CT and mobile C-arm fluoroscopy is an effective and safe treatment option for NB in short time follow-up. It would be well improved in the bladder storage function, sphincter synergetic function and emptying efficiency by video-urodynamics examination in this study.

Trial registration: Chinese Clinical Trial Registry. ChiCTR2100050290. Registered August 25 2021. http://www.chictr.org.cn/index.aspx.

Assessing the outcomes of parasacral transcutaneous electrical nerve stimulation (PTENS) in the treatment of enuresis in children: A systematic review and meta-analysis of randomized control trials

INTRODUCTION

Nocturnal enuresis (NE) is a common pathology in children that can have significant behavioral, emotional, and social impacts on a child's life. Recent studies have assessed PTENS as a potential treatment method for NE, particularly in those who do not respond to initial first-line treatments. Literature has shown varying results with regard to its success. There has been no systematic review and meta-analysis to date assessing outcomes following this treatment.

OBJECTIVES

Despite multiple studies showing the potential benefits of PTENS in NE, there has been no consensus regarding its efficacy. The aim of this study was to systematically analyze the effects of PTENS on children with NE.

STUDY DESIGN

In September 2021, a search of PubMed, Embase and the Cochrane Library was carried out for studies relating to outcomes following PTENS in children with NE. Studies included were original publication English language randomized controlled trial (RCT's) with at least ten children receiving parasacral transcutaneous electrical nerve stimulation (PTENS). After assessing for relevant studies, data were collated and analyzed from the included studies. Risk of bias was assessed using the Cochrane seven domain assessment. Our primary outcome was response and nonresponse to treatment. These results were combined in a fixed effects meta-analysis model to obtain an overall estimate of the success rate. Information regarding demographics was also collected. There was no external funding for this review.

RESULTS

Of 145 studies found initially, four RCT's (208 children) were included. The weighted mean rate of full response to active PTENS was 10.8% (0%-19%). All studies considered, meta-analysis showed no difference between PTENS and controls (RR: 0.70, 95% confidence interval [CI: 0.37-1.32]). Subgroup analysis of monosymptomatic enuresis showed no effect of PTENS compared to controls (RR = 0.58, 95% CI: [0.24-1.42]). When grouped, studies comparing PTENS to sham/behavioral treatment showed no benefit compared to controls (RR = 0.81, 95% CI: [0.05-12.53]) and those comparing PTENS to biofeedback/interferential current (IFC) showed no difference to controls (RR = 0.69, 95% CI: [0.36-1.33]). There was no evidence of a difference between cases and controls between these latter subgroups (RR = 0.70, 95% CI: [0.37-1.32]).

DISCUSSION/CONCLUSION

Our results suggest that PTENS has no clear benefit in the management of children with NE compared to controls. Subgroup analysis showed that its use in monosymptomatic NE has no clear advantage. However, this review has highlighted the need for further high quality studies. Limitations to this review included a relatively small sample size and the use of prior or concomitant therapies.

Clinical Review of Neuromusculoskeletal Complementary and Alternative Approaches for the Treatment of Chronic Pelvic Pain Syndrome

Chronic pelvic pain syndrome (CPPS) is a functional pain disorder characterized by ongoing pain in the apparent absence of clinically identifiable causes. The prevalence of functional pain disorders demonstrates the importance of adequate management of ongoing symptomatology, but due to the uncertain etiology and myriad patient presentation phenotypes, reliable treatment options are difficult to implement. New interventions involving non-pharmacological approaches to pain management have been investigated across a spectrum of clinical and pre-clinical studies. Given that conservative care such as exercise, counseling, and musculoskeletal therapy is widely recommended as first-line treatment for CPPS, an updated review of these and related methodologies are needed. Familiarizing physicians and the public with the newest evidence for complementary and alternative medicine (CAM) and other conservative care treatments will assist with the promotion of evidence-based practices in a safe and reliable manner. This review aimed to summarize the current evidence and proposed mechanisms for non-pharmacological treatment specific to CAM and management of chronic pelvic pain centered on neuromusculoskeletal focused intervention such as acupuncture, auriculotherapy, manipulation, manual therapy, myofascial release, and phototherapy. The discussion suggests that reported improvements in pelvic pain or related symptomatology may be attributed to changes in the peripheral inflammasome and somatic origins of peripheral sensitization. Robustness of the included clinical studies is discussed throughout the review, and attention is paid to delineating inclusion criteria of formally diagnosed CPPS compared to general pelvic or abdominal pain. Overall, this review consolidates the current state of evidence regarding the utilization of non-traditional interventions using CAM techniques for the management of chronic pelvic pain and recommends a future direction for the field.

[Interstitial cystitis: interventions and surgery - more than a last resort?]

Interstitial cystitis is an underdiagnosed chronic-relapsing to chronic-progressive urinary bladder disease, whose pathogenesis and aetiology has not been fully elucidated. The disease itself cannot be cured and treatment is symptomatic. Treatment options comprise conservative and medicinal approaches as well as a large number of interventional/surgical procedures. These include intravesical instillation, transurethral procedures such as injections of botulinum toxin A, corticosteroids and local anaesthetics, hydrodistension and neuromodulation as well as (laser) fulguration, resection and cystectomy. Although surgical procedures are considered a late option and are often referred to as last-resort therapy, these interventional options often show good to very good response rates, manageable complications and a favourable risk-benefit evaluation. An overall generalisation of surgery as a last-resort treatment option should therefore be avoided and its use should be discussed based on the individual needs of each patient.

[Sacral neuromodulation as treatment of non-neurological vesical emptying disorders]

GOAL

The goal was to evaluate the results of sacral neuromodulation (SNM) in non-neurological vesical emptying disorders.

PATIENTS AND METHODS

From February 2010 to October 2017, 28 patients presenting voiding symptoms or a non-obstructive chronic urine retention without neurological cause have been operated for an SNM (test phase). The test was positive in case of decreased number of proper intermittent self-catheterization (SC) or post-voiding residual urine (PVR) of at least 50 %. A 100 % positive result meant the return to a spontaneous voiding without SC with a non-significative PVR (<100ml).

RESULTS

The median follow-up was of 53.2±21.2 months. Twenty-four (85.7%) tests were positive, from which twenty-two (78.6%) were 100% positive. 16 (84.2%) out of 19 patients with SC had spontaneous voiding without PVR. The number of daily SC decreased from 4.6±1.5 to 0.4±1.2 in post-operative (P<0.001). The PVR was of 287.1±170.4ml vs. 30.4±48.6ml in post-operative (P<0.001). Fourteen patients (58.3%) underwent at least one chirurgical revision or a removal of material ; mainly for loss of efficiency, end of battery, electrode migration and pain on material. At the end of the follow-up, 70.8% of the responding patients had their device still efficient.

CONCLUSION

Results showed that SNM appears to be an efficient treatment of non-neurological emptying vesical troubles. Nevertheless, the re-operation rate was still significant.

LEVEL OF EVIDENCE

3.

Therapeutic effects of non-invasive, individualized, transcranial neuromodulation treatment for voiding dysfunction in multiple sclerosis patients: study protocol for a pilot clinical trial

Background

Voiding dysfunction (VD) is a common neurogenic lower urinary tract dysfunction (NLUTD) in multiple sclerosis (MS) patients. Currently, the only effective management for VD and urinary retention in MS patients is catheterization, prompting us to look for novel therapeutic options beyond the bladder, such as the brain. Transcranial rotating permanent magnet stimulator (TRPMS) is a non-invasive, portable, multifocal neuromodulator that simultaneously modulates multiple cortical regions, enhancing or attenuating strengths of functional connections between these regions. The objective of this pilot clinical trial is to evaluate the feasibility of a TRPMS trial to address lower urinary tract symptoms in MS patients, through investigating the therapeutic effects of TRPMS in modulating brain regions during voiding initiation and mitigating VD in female MS individuals.

Methods

Ten adult female MS patients with VD (defined as having %post-void residual/bladder capacity (%PVR/BC) ≥ 40% or Liverpool nomogram percentile < 10%) will be recruited for this study. Concurrent urodynamic and functional MRI evaluation with a bladder filling/emptying task repeated three to four times will be performed at baseline and post-treatment. Predetermined regions of interest and their blood-oxygen-level-dependent (BOLD) activation at voiding initiation will be identified on each patient’s baseline anatomical and functional MRI scan, corresponding to the microstimulators placement on their individualized TRPMS treatment cap to either stimulate or inhibit these regions. Patients will receive 10 40-min treatment sessions. Non-instrumented uroflow and validated questionnaires will also be collected at baseline and post-treatment to evaluate clinical improvement.

Discussion

Despite the crucial role of the central nervous system in urinary control and its sensitivity to MS, there has been no treatment for urinary dysfunction targeting the brain centers that are involved in proper bladder function. This trial, to our knowledge, will be the first of its kind in humans to consider non-invasive and individualized cortical modulation for treating VD in MS patients. Results from this study will provide a better understanding of the brain control of neurogenic bladders and lay the foundation for a potential alternative therapy for VD in MS patients and other NLUTD in a larger neurogenic population in the future.

Trial registration

This trial is registered at ClinicalTrials.Gov (NCT03574610, 2 July 2018.) and Houston Methodist Research Institute IRB (PRO00019329)

Fowler's Syndrome-The Cause of Urinary Retention in Young Women, Often Forgotten, but Significant and Challenging to Treat

Urinary retention in young women is a relatively rare clinical problem and is often underdiagnosed. In particular, functional causes of urinary retention pose a diagnostic challenge. One of them is Fowler's syndrome, which is associated with impaired urethral relaxation. Fowler's syndrome is characterized by a large bladder capacity, reduced sensation, increased maximal urethral closure pressure, and detrusor underactivity. Several hypotheses have arisen to explain the cause of urethral relaxation disorders: hormonal changes characteristic of Polycystic Ovary Syndrome (PCOS), causing abnormal stabilization of the muscle membrane, primary failure of relaxation of the striated muscle of the urethra sphincter, and increased urethral afferent activity, inhibiting the bladder afferent signals from reaching the brain by potentiating a spinal mechanism of urinary continence. Currently, sacral neuromodulation is the only intervention that can restore an atypical voiding pattern in women with Fowler's syndrome. The therapeutic effectiveness exceeds 70%, although the revision rate is relatively high, exceeding 50%. Well-designed, long-term prospective studies comparing sacral neuromodulation (SNM) with other therapies such as pelvic floor muscle physiotherapy are warranted to offer the best patient-tailored treatment.

Effects of temporary sacral nerve stimulation on gastrointestinal motility and function in patients with chronic refractory slow-transit constipation

BACKGROUND

The efficacy of sacral nerve stimulation (SNS) on patients with chronic refractory slow-transit constipation is controversial and its mechanism of action on gastrointestinal motility and transit is not fully understood. The aim of this study was to document the effects of temporary SNS on the gastrointestinal and biliary tract motility and on gastrointestinal transit in patients with refractory slow-transit constipation.

METHODS

This was a prospective interventional study. Patients with slow-transit chronic constipation, unresponsive to any conservative treatment, were enrolled between January 2013 and December 2018. Patients' quality of life [patient assessment of constipation quality of life (PAC-QOL) questionnaire], constipation scores (Cleveland Clinic Constipation Score) colonic transit time (CTT), orocecal transit time (OCTT), gastric and gallbladder kinetics, together with the assessment of the autonomic nerve function were evaluated before and during temporary SNS.

RESULTS

14 patients (12 females, median age 38 years, range 24-42 years) had temporary SNS. The Cleveland Clinic Constipation Score did not change compared to baseline (23 ± 3 vs 21.4; p = 070). The PAC-QOL did not improve significantly during the stimulation period. Gallbladder/stomach motility (half-emptying time) did not change significantly before and after SNS. OCTT was delayed at baseline, as compared to standard internal normal values, and did not change during SNS. CTT did not improve significantly, although in two patients it decreased substantially from 97 to 53 h, and from 100 to 65 h.

CONCLUSIONS

Temporary SNS did not have any effect on upper/lower gastrointestinal motility and transit in patients with severe constipation.

Magnetic resonance image connectivity analysis provides evidence of central nervous system mode of action for parasacral transcutaneous electro neural stimulation - A pilot study

INTRODUCTION

Parasacral transcutaneous electriconeural stimulation (pTENS) is a common treatment modality for patients with overactive bladder (OAB). Its mechanism of effectiveness has yet to be elucidated. Recent studies with fMRI in adults with implanted sacral nerve stimulators impute its effectiveness on changes in the brain involving the anterior cingulate cortex (ACC) and prefrontal cortex (PFC).

AIM

The study set out to evaluate brain connectivity utilizing functional MRI to the outline the mechanism of action of pTENS in the brain.

METHODS

Ten adult volunteers without urinary tract symptoms underwent fMRI. Electrodes were placed on the skin at sacral level (S2) (Experimental Stimulation - pTENS) and on the right scapular region (Sham Stimulation - sTENS). Stimulation was done twice on each site for 6 min at a frequency of 10 Hz and pulse width of 260 μs and intensity determined by the motor threshold. A 6 min resting state fMRI was also done twice as control. Functional connectivity data was acquired during each state (resting, pTENS and sTENS). Standard functional connectivity preprocessing was performed. Seed connectivity was examined to investigate changes in ACC functional connectivity between the stimulations and resting-state conditions. Significance was assessed at p < 0.05 corrected for multiple comparisons.

RESULTS

For all conditions (pTENS, sTENS, and rest), standard patterns of ACC connectivity were detectable with strong connectivity between the ACC and subcortical regions and between the ACC and the frontal lobe. Functional connectivity between ACC seed and the dorsal lateral prefrontal cortex (DLPFC) was significantly increased during pTENS compared to rest. sTENS did not increase connectivity between the ACC seed and DLPFC when compared to rest.

DISCUSSION

Preliminary results indicate that ACC is a major site of activation during pTENS. Increased connectivity between ACC and DLPFC may be a possible mechanism of pTENS effectiveness, which appears to be specific to pTENS compared to sTENS. This study is limited to the small size at this time which prevents further investigation at other sites in the brain.

CONCLUSIONS

The study confirms our original aim which was to define if parasacral TENS actually has a central effect.

Cerebellum and micturition: what do we know? A systematic review

Aims

Micturition depends on a complex voluntary and involuntarily neuronal network located at various levels of the nervous system. The mechanism is highly dependent on the hierarchical organization of central nervous system pathways. If the role of the cortex and brainstem centres is well established, the role of other subcortical areas structures, such as the cerebellum is poorly understood. We are interested in discussing the current knowledge on the role of cerebellum in micturition.

Methods

A systematic search is performed in the medical literature, using the PubMed database with the keyword « cerebellum ». The latter is combined with «urination » OR « micturition » OR « urinary bladder ».

Results

Thirty-one articles were selected, focussing on micturition and describing the role of the cerebellum. They were grouped in 6 animal experimental studies, 20 functional brain imaging in micturition and 5 clinical studies.

Conclusions

Although very heterogeneous, experimental and clinical data clearly indicate the cerebellum role in the micturition control. Cerebellum modulates the micturition reflex and participates to the bladder sensory-motor information processing. The cerebellum is involved in the reflex micturition modulation through direct or indirect pathways to major brainstem or forebrain centres.

Sacral nerve stimulation increases gastric accommodation in rats: a spinal afferent and vagal efferent pathway

Impaired gastric accommodation (GA) has been frequently reported in various gastrointestinal diseases. No standard treatment strategy is available for treating impaired GA. We explored the possible effect of sacral nerve stimulation (SNS) on GA and discovered a spinal afferent and vagal efferent mechanism in rats. Sprague-Dawley rats (450-500 g) with a chronically implanted gastric cannula and ECG electrodes were studied in a series of sessions to study: 1) the effects of SNS with different parameters on gastric tone, compliance, and accommodation using a barostat device; two sets of parameters were tested as follows: parameter 1) 5 Hz, 500 µs, 10 s on 90 s off; 90% motor threshold and parameter 2) same as parameter 1 but 25 Hz; 2) the involvement of spinal afferent pathway via detecting c-fos immunoreactive (IR) cells in the nucleus of the solitary tract (NTS) of the brain; 3) the involvement of vagal efferent activity via the spectral analysis of heart rate variability derived from the ECG; and 4) the nitrergic mechanism, N^ω-nitro-l-arginine methyl ester (l-NAME), a nitric oxide synthase (NOS) inhibitor, was given before SNS at 5 Hz. Compared with sham-SNS: 1) SNS at 5 Hz inhibited gastric tone and increased gastric compliance and GA. No difference was noted between the stimulation frequencies of 5 and 25 Hz. 2) SNS increased the expression of c-fos in the NTS. 3) SNS increased cardiac vagal efferent activity and decreased the sympathovagal ratio. 4) l-NAME blocked the relaxation effect of SNS. In conclusion, SNS with certain parameters relaxes gastric fundus and improves gastric accommodation mediated via a spinal afferent and vagal efferent pathway.NEW & NOTEWORTHY Currently, there is no adequate medical therapy for impaired gastric accommodation, since medications that relax the fundus often impair antral peristalsis and thus further delay gastric emptying that is commonly seen in patients with functional dyspepsia or gastroparesis. The advantage of the potential sacral nerve stimulation therapy is that it improves gastric accommodation by enhancing vagal activity, and the enhanced vagal activity would lead to enhanced antral peristalsis rather than inhibiting it.

Transcutaneous Electrical Spinal Cord Neuromodulator (TESCoN) Improves Symptoms of Overactive Bladder

Neuromodulation is a therapeutic technique that is well-established in the treatment of idiopathic Lower urinary tract (LUT) dysfunction such as overactive bladder (OAB). We have recently developed a novel neuromodulation approach, Transcutaneous Electrical Spinal Cord Neuromodulation (TESCoN) and demonstrated its acute effects on LUT dysfunction after spinal cord injury (SCI) during urodynamic studies. We found that TESCoN can promote urinary storage and induce urinary voiding when delivered during urodynamic studies. The objective of this study was to determine whether TESCoN can retrain the spinal neural networks to induce chronic improvement in the LUT, such that positive changes can persist even in the absence of stimulation. In addition, we wished to examine the effect of TESCoN on LUT dysfunction due to multiple pathologies. To achieve this objective, 14 patients [SCI = 5, stroke = 5, multiple sclerosis (MS) = 3, and idiopathic OAB (iOAB) = 1] completed 24 sessions of TESCoN over the course of 8 weeks. Patients completed urodynamic studies before and after undergoing TESCoN therapy. Additionally, each subject completed a voiding diary and the Neurogenic Bladder Symptom Score questionnaire before and after receiving TESCoN therapy. We found that TESCoN led to decreased detrusor overactivity, improved continence, and enhanced LUT sensation across the different pathologies underlying LUT dysfunction. This study serves as a pilot in preparation for a rigorous randomized placebo-controlled trial designed to demonstrate the effect of TESCoN on LUT function in neurogenic and non-neurogenic conditions.

NEW AND NOTEWORTHY

Non-Surgical modality to reduce incidence of urinary incontinence and improve neurogenic bladder symptom scores (NBSS) in individuals with neurogenic bladder due to spinal cord injury or stroke.

Sacral Neuromodulation: Mechanism of Action

Although the mechanism of action of sacral neuromodulation (SNM) is still not fully elucidated, it seems to involve modulation of spinal cord reflexes and brain networks by peripheral afferents according to findings from neurophysiology, electroencephalography, positron emission tomography, and magnetic resonance imaging studies. Moreover, motor effects mediated via efferents on direct stimulation cannot be fully excluded. In this mini-review, we summarize current knowledge on the mechanism of action of SNM. PATIENT SUMMARY: We reviewed the literature on the mechanism of action of sacral neuromodulation, in which electrical stimulation is applied to the nerves that regulate bladder activity. The mechanism seems to involve modulation of spinal cord reflexes and brain networks by peripheral sensory and possibly motor neurons.

Sacral neuromodulation for female pelvic floor disorders

Objective: To systematically review available studies on the effectiveness and safety of sacral neuromodulation (SNM) in women with various pelvic floor disorders not responding to more conservative treatment, as SNM is indicated in such women.

Methods: Data source: We did a systematic review through the PubMed and the Cochrane Library according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from 1998 to 2018 in English using the keywords ‘Sacral Neuromodulation’ and ‘Sacral Nerve Stimulation’.

Study selection: Randomised controlled trials and prospective studies were selected, with a minimum sample size of 20 patients and ≥6 months of follow-up.

Results: We identified 19 articles. A ≥50% reduction in symptoms qualifies the patient for a permanent implant. Several advances have been introduced into SNM to decrease the invasiveness of the procedure, including a smaller implantable pulse generator battery (improved comfort) and better localisation of the lead wire (improved outcome). The literature reports success for overactive bladder (OAB) to range between 56% and 68% (up to 80%). We report a 5-year therapeutic success rate of 67%. In our previous studies, 38% of our patients with urge urinary incontinence achieved complete continence at 60-months follow-up, with a therapeutic response rate of 57%. Effectiveness in patients with urinary retention and faecal incontinence are about 70% and 85%, respectively. Effectiveness in interstitial cystitis/bladder pain syndrome appears to be lower compared with OAB.

Conclusion: SNM is a safe and effective therapy for women with various pelvic floor disorders.

Abbreviations: BONT: botulinum toxin; FDA: USA Food and Drug Administration; FS: Fowler’s syndrome; FI: faecal incontinence; IC/BPS: interstitial cystitis/bladder pain syndrome; ICIQ-OABqol: International Consultation on Incontinence Modular Questionnaire-Overactive Bladder Symptoms Quality of Life; INS: implantable neurostimulator; OAB: overactive bladder; PET: positron emission tomography; PNE: peripheral nerve evaluation; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTNM: posterior tibial nerve modulation; PVR: post-void residual urine; QoL: quality of life; RCT: randomised controlled trial; SNM: sacral neuromodulation; (U)UI: (urgency) urinary incontinence

Sacral neuromodulation treating chronic pelvic pain: a meta-analysis and systematic review of the literature

INTRODUCTION AND HYPOTHESIS

Sacral neuromodulation (SNM) is gaining popularity as a treatment option for chronic pelvic pain (CPP). Our hypothesis is that SNM is effective in improving CPP.

METHODS

A systematic search was conducted through September 2018. Peer-reviewed studies using pre- and postpain intensity scores were selected. The primary outcome was pain improvement on a 10-point visual analog scale (VAS) (adjusted or de novo) in patients with CPP. Secondary outcomes included comparing SNM approaches and etiologies and evaluating lower urinary tract symptoms (LUTS).

RESULTS

Fourteen of 2175 studies, evaluating 210 patients, were eligible for further analysis. The overall VAS pain score improvement was significant [weighted mean difference (WMD) -4.34, 95% confidence interval (CI) = -5.22, to-3.64, p < 0.0001)]. Regarding SNM approach, both standard and caudal approaches had significant reduction in pain scores: WMD -4.32, CI 95% = -5.32, to -3.31 (p < 0.001) for the standard approach, compared with WMD -4.63, 95% CI = -6.57 to -2.69 (P < 0.001), for the caudal approach (p = 0.75). While significant improvement in pain was observed both in patients with and without interstitial cystitis/bladder pain syndrome (IC/BPS), the observed improvement was lower in patients with (WMD -4.13, CI 95% -5.36 to -2.90 versus without (WMD -5.72, CI 95% = -6.18, to-5.27) IC/BPS (p = 0.02). SNM was effective in treating voiding symptoms (frequency, urgency, nocturia) associated with IC/BPS (all p < 0.01).

CONCLUSIONS

SNM is an effective therapy for CPP in both IC/BSP and non-IC/BSP patients, with better results in non-IC/BSP patients. Outcomes of the antegrade caudal approach were comparable with the standard retrograde approach.

Functional brain imaging in voiding dysfunction

PURPOSE OF REVIEW

Voiding dysfunction (VD) is morbid, costly, and leads to urinary tract infections, stones, sepsis, and permanent renal failure. Evaluation and diagnosis of VD in non-obstructed patients can be challenging. Potential diagnostic and therapeutic options beyond the bladder, such as brain centers involved in voiding have been proposed as promising targets. This review focuses on current and future applications of functional neuroimaging in human in voiding and in patients with VD.

RECENT FINDINGS

The current understanding of brain centers, and their roles in initiating, maintaining and/or modulating voiding, is rudimentary in humans and in patients with VD. With the advent and advancement in functional neuroimaging we are gaining more insight into specific brain regions involved in the voiding phase of micturition. In healthy individuals, right dorsomedial pontine tegmentum, periaqueductal grey, hypothalamus, and the inferior, medial and superior frontal gyrus have been identified as regions of interest in voiding.

SUMMARY

Functional neuroimaging could suggest new diagnostic methods and provides crucial steps towards therapeutic options for the morbid and intractable VD condition, in patients with neurogenic (e.g. MS or Strokes) or non-neurogenic VD (e.g. underactive bladder or Fowler's syndrome).

[Neuromodulation of lower urinary tract dysfunction]

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

Sacral neuromodulation and sexual function: a systematic review and meta-analysis of the literature

INTRODUCTION AND HYPOTHESIS

Sexual function is being increasingly recognized as an important patient-reported outcome. Sacral neuromodulation (SNM) is a treatment with an expanding list of indications. The effect of sacral neuromodulation on sexual function has been examined in a number of studies with variable results. In this review, we aim to systematically review the literature and pool the data if appropriate.

METHODS

The literature search was conducted primarily on the Healthcare Databases Advanced Search (HDAS) platform using the Medline, EMBASE and CINHAL search engines. Of 196 initial citations, 17 articles met our predefined inclusion criteria. Thirteen studies reported enough information to be included in our meta-analysis. RevMan5 software was used for analysis.

RESULTS

Eight of 17 studies reported a positive effect of SNM on sexual function. Pooled analysis of data from 11 studies involving 573 patients before SNM and 438 patients after SNM showed significant improvement in sexual function (SMD = -0.39; 95% CI: -0.58 to -0.19; p = 0.0001). The results remained significant in most subgroup analyses except in patients suffering from fecal incontinence.

CONCLUSIONS

SNM in women with pelvic floor disorders, especially bladder dysfunction, seems to have a positive effect on sexual function. This needs to be verified in adequately powered primary research using sexual function as the primary outcome.

Overactive Bladder in Children

Overactive bladder (OAB) is clinically defined as the presence of urinary urgency and may be associated with diurnal urinary incontinence, frequency, and enuresis, and/or constipation. In children aged 5–10 years, the prevalence is 5–12%. Association with emotional disorders is widely described in the literature. Constipation is associated with voiding symptoms because of crosstalk between the gastrointestinal tract and the urinary tract. OAB is believed to be multifactorial. Correct functioning between the pontine micturition centre, the periaqueductal grey matter, anterior cingulate gyrus, and prefrontal cortex is important for correct voiding development and the process of maturation. Patients with OAB have greater anterior cingulate gyrus activity and deactivation of the pontine micturition centre urinary inhibition process, leading to a greater frequency of bladder repletion sensation. Urotherapy is the first treatment to be initiated and aims to change behavioural patterns inthese patients. Other treatment options are anticholinergics, with oxybutynin being the most widely studied, but also described is the use of tolterodine, darifenacin, and mirabegron. Alternative treatments, such as nerve stimulation in the parasacral or the posterior tibial area, have shown improvement of symptoms in comparative studies with conventional drug treatment, and, in refractory cases, botulinum toxin A is an option. In this article, we review the pathophysiology, associated conditions, and aspects related to diagnosis and treatment of OAB.

The Role of the Periaqueductal Gray Matter in Lower Urinary Tract Function

The periaqueductal gray matter (PAG), as one of the mostly preserved evolutionary components of the brain, is an axial structure modulating various important functions of the organism, including autonomic, behavioral, pain, and micturition control. It has a critical role in urinary bladder physiology, with respect to storage and voiding of urine. The PAG has a columnar composition and has extensive connections with its cranially and caudally located components of the central nervous system (CNS). The PAG serves as the control tower of the detrusor and sphincter contractions. It serves as a bridge between the evolutionary higher decision-making brain centers and the lower centers responsible for reflexive micturition. Glutamatergic cells are the main operational neurons in the vlPAG, responsible for the reception and relay of the signals emerging from the bladder, to related brain centers. Functional imaging studies made it possible to clarify the activity of the PAG in voiding and filling phases of micturition, and its connections with various brain centers in living humans. The PAG may be affected in a wide spectrum of disorders, including multiple sclerosis (MS), migraine, stroke, Wernicke’s encephalopathy, and idiopathic normal pressure hydrocephalus, all of which may have voiding dysfunction or incontinence, in certain stages of the disease. This emphasizes the importance of this structure for the basic understanding of voiding and storage disorders and makes it a potential candidate for diagnostic and therapeutic interventions.

Specific Changes in Brain Activity during Urgency in Women with Overactive Bladder after Successful Sacral Neuromodulation: A Functional Magnetic Resonance Imaging Study

PURPOSE

The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during urgency before and after sacral neuromodulation in women with overactive bladder and according to the response to treatment.

MATERIALS AND METHODS

Women with refractory overactive bladder who elected sacral neuromodulation were invited to undergo functional magnetic resonance imaging before and after treatment. During imaging the bladder was filled until urgency was experienced. Regions of interest were identified a priori and brain activity in these regions of interest was compared before and after treatment as well as according to the treatment response. Whole brain exploratory analysis with an uncorrected voxel level threshold of p <0.001 was also performed to identify additional brain regions which changed after sacral neuromodulation.

RESULTS

Of the 12 women who underwent a pretreatment functional magnetic resonance imaging examination 7 were successfully treated with sacral neuromodulation and underwent a posttreatment examination. After sacral neuromodulation brain activity decreased in the left anterior cingulate cortex, the bilateral insula, the left dorsolateral prefrontal cortex and the bilateral orbitofrontal cortex (each p <0.05). No new brain regions showed increased activity after sacral neuromodulation. Pretreatment brain activity levels in the bilateral anterior cingulate cortex, the right insula, the bilateral dorsolateral prefrontal cortex, the right orbitofrontal cortex, the right supplementary motor area and the right sensorimotor cortex were higher in women who underwent successful treatment (each p <0.05).

CONCLUSIONS

Brain activity during urgency changes after successful sacral neuromodulation. Sacral neuromodulation may be more effective in women with higher levels of pretreatment brain activity during urgency.

Female bladder outlet obstruction: an update on diagnosis and management

PURPOSE OF REVIEW

The diagnosis and evaluation of bladder outlet obstruction (BOO) in women remains a challenging topic. The goal of this study is to review recent literature and summarize the diagnosis and management of BOO with special focus on recent progress.

RECENT FINDINGS

In recent years, numerous advances in the area of female BOO have taken place including a movement towards unified diagnostic criteria, summary of functional and anatomic causes, and exploration of potential diagnostic options.

SUMMARY

This review discusses the known diagnosis and management of female bladder outlet obstruction, yet highlights specific functional causes, new criteria available for diagnosis, and long-term results of treatment options.

Sacral neuromodulation blocks pudendal inhibition of reflex bladder activity in cats: insight into the efficacy of sacral neuromodulation in Fowler's syndrome

This study tested the hypothesis that sacral neuromodulation, i.e., electrical stimulation of afferent axons in sacral spinal root, can block pudendal afferent inhibition of the micturition reflex. In α-chloralose-anesthetized cats, pudendal nerve stimulation (PNS) at 3-5 Hz was used to inhibit bladder reflex activity while the sacral S1 or S2 dorsal root was stimulated at 15-30 Hz to mimic sacral neuromodulation and to block the bladder inhibition induced by PNS. The intensity threshold (T) for PNS or S1/S2 dorsal root stimulation (DRS) to induce muscle twitch of anal sphincter or toe was determined. PNS at 1.5-2T intensity inhibited the micturition reflex by significantly ( P < 0.01) increasing bladder capacity to 150-170% of control capacity. S1 DRS alone at 1-1.5T intensity did not inhibit bladder activity but completely blocked PNS inhibition and restored bladder capacity to control level. At higher intensity (1.5-2T), S1 DRS alone inhibited the micturition reflex and significantly increased bladder capacity to 135.8 ± 6.6% of control capacity. However, the same higher intensity S1 DRS applied simultaneously with PNS, suppressed PNS inhibition and significantly ( P < 0.01) reduced bladder capacity to 126.8 ± 9.7% of control capacity. S2 DRS at both low (1T) and high (1.5-2T) intensity failed to significantly reduce PNS inhibition. PNS and S1 DRS did not change the amplitude and duration of micturition reflex contractions, but S2 DRS at 1.5-2T intensity doubled the duration of the contractions and increased bladder capacity. These results are important for understanding the mechanisms underlying sacral neuromodulation of nonobstructive urinary retention in Fowler's syndrome.

Sacral Neuromodulation for Fecal Incontinence: A Review of the Central Mechanisms of Action

OBJECTIVE

Fecal incontinence (FI) has a devastating effect on the quality of life and results in social isolation. Sacral neuromodulation (SNM) is proven to be an effective, minimal invasive treatment modality for FI. Despite the increasing application of SNM, the exact mechanisms of action remain unclear. The initial assumption of peripheral motor neurostimulation is not supported by increasing evidence, which report effects of SNM outside the pelvic floor. A new hypothesis states that afferent signals to the brain are essential for a successful therapy. This study aimed to review relevant studies on the central mechanism of SNM in FI.

METHODS

Clinical and experimental studies on the central mechanisms, both brain and spinal cord, of SNM for FI up to December 2015 were evaluated.

RESULTS

In total, 8 studies were found describing original data on the central mechanism of SNM for FI. Four studies evaluated the central effects of SNM in a clinical setting and 4 studies evaluated the central effects of SNM in an experimental animal model. Results demonstrated a variety of (sub)cortical and spinal changes after induction of SNM.

CONCLUSION

Review of literature demonstrated evidence for a central mechanism of action of SNM for FI. The corticoanal pathways, brainstem, and specific parts of the spinal cord are involved.

Increase of n-NOS and i-NOS in Rat Colon After Sacral Neuromodulation

OBJECTIVE

Sacral neuromodulation (SNM) is proposed to treat different anorectal dysfunctions but its mechanism of action is not yet known. Our previous study demonstrated how SNM can significantly increase neuronal nitric oxide synthase NOS (n-NOS) and inducible NOS (i-NOS) expression in the anus and rectum of rats. There are no reports regarding the relation between SNM and NOS in colonic cells: our aim was to assess NOS expression in colonic rat model after SNM.

MATERIALS AND METHODS

Twenty-six female Sprangue-Dawley rats were considered: group I, normal control rats; group II, sham treatment rats, in whom electrodes for electrical stimulation were placed in S1 foramen bilaterally and left in place, without performing neuromodulation; group III, rats in whom SNM was performed. After 14 days, the rats were sacrificed and we evaluated n-NOS and i-NOS in colonic specimens by immunohistochemistry and Western Blot analysis.

RESULTS

Western Blot analysis showed that levels of n-NOS and i-NOS were higher in colon of the III group rats respect to the others; in particular, immunohistochemistry revealed that, after neuromodulation, n-NOS expression in the muscle cells and i-NOS expression in glandular epithelium and nervous cells were highly represented (p < 0.05).

CONCLUSION

Our study showed that in colon, SNM is able to influence NO synthesis, activating n-NOS expression in muscle cells and i-NOS expression in glandular epithelium and nervous cells. Our study showed a complex colonic response to SNM. This experimental model could be applied to better understand the mechanism of action of SNM in bowel dysfunction.

Pathophysiology of the Underactive Bladder: Evolving New Concepts

PURPOSE OF REVIEW

Underactive Bladder (UAB) is an emerging concept of voiding dysfunction, building on a tradition of often overlapping and confusing terminologies describing the patient experience, urodynamic function, and pathophysiology. This confusion of symptoms with function with pathology has hampered development of an effective disease model.

RECENT FINDINGS

As with other urinary symptoms, the relationship of voiding symptoms to urodynamic dysfunction is variable. Efforts are underway to formally define UAB as a collection of symptoms related to voiding. Defined as voiding symptoms, UAB cannot be reliably linked to detrusor underactivity (DU) nor to detrusor weakness.

SUMMARY

Progress will be made by characterizing the functional disorders underlying UAB symptoms, examining the biology of these linkages, re-conceptualizing urinary control as one part of a more global biologic adaptive physiology, and determining the relationships of central and peripheral pathologies leading to disrupted control mechanisms.

Real-Time Changes in Brain Activity during Sacral Neuromodulation for Overactive Bladder

PURPOSE

We performed functional magnetic resonance imaging to identify changes in brain activity during sacral neuromodulation in women with overactive bladder who were responsive to therapy.

MATERIALS AND METHODS

Women recruited into the study had nonneurogenic refractory overactive bladder, responded to sacral neuromodulation and had had a stable program for at least 3 months with no subsequent overactive bladder treatment. Enrolled patients completed validated symptom and quality of life instruments before functional magnetic resonance imaging. Stimulus settings were recorded, devices were switched off for a 5-day washout and instruments were repeated. Three functional magnetic resonance imaging scans with simultaneous sacral neuromodulation stimulation were performed below, at and above stimulus sensory threshold using a block design. This yielded brain activity maps represented by changes in blood oxygenation level dependence. A total of 5 stimulator off and 4 stimulator on cycles of 42 seconds each were imaged. Group analysis was done using a single voxel p value of 0.05 with a false-positive error of 0.05 on cluster analysis.

RESULTS

Six of the 13 patients enrolled completed functional magnetic resonance imaging. Median age was 52 years (range 36 to 64). Urinary symptoms and voiding diary data worsened with washout. Overall brain activation generally progressed with increasing stimulation amplitude. However, activation of the right inferior frontal gyrus remained stable while deactivation of the pons and the periacqueductal gray matter only occurred with subsensory stimulation. Sensory stimulation activated the insula but deactivated the medial and superior parietal lobes. Suprasensory stimulation activated multiple structures and the expected S3 somatosensory region. All devices had normal impedance after functional magnetic resonance imaging.

CONCLUSIONS

Functional magnetic resonance imaging confirmed that sacral neuromodulation influences brain activity in women with overactive bladder who responded to therapy. These changes varied with stimulus intensity.

Effectiveness of BTX-A and neuromodulation in treating OAB with or without detrusor overactivity: a systematic review

INTRODUCTION AND HYPOTHESIS

Patients with refractory overactive bladder (OAB) pose a therapeutic challenge. Guidelines such as those from the National Institute for Health and Care Excellence recommend invasive treatments such as botulinum toxin-A ((BTX-A), sacral neural stimulation (SNS) etc. only if there is detrusor overactivity (DO) on urodynamics.

METHODS

Our aim was to systematically evaluate evidence based on the presence or absence of DO in relation to differences in effectiveness and complications related to invasive treatment in patients with refractory OAB. We carried out a systematic search of Cochrane, MEDLINE, Embase, CINAHL, LILACS, meta-Register of Controlled Trials (mRCT), CENTRAL, and Google Scholar databases from inception until April 2016. Abstracts presented at IUGA, ICS and EAU conferences (until April 2016) were included and journals that were hand searched.

RESULTS

We found five studies (two prospective cohort studies and subgroup analyses of two randomized controlled trials (RCTs) and one cohort study for BTX-A, one multicenter prospective cohort study for percutaneous tibial nerve stimulation (PTNS) and three (one RCT and two cohort studies) for SNS. The outcomes in patients without (n = 77) or with (n = 135) DO were similar in the context of urodynamic findings, bladder diaries, quality of life (QoL) questionnaires, etc. when treated with BTX-A [odds ratio (OR) 1.52, 95% confidence interval (CI) 0.40-5.77] or SNS (50 patients without and 81 with DO; OR1.37, CI 0.76-2.48). Outcomes for PTNS (based on a single study) seem to be better in patients without DO.

CONCLUSION

The limited evidence suggests that urodynamic diagnosis of DO does not alter patient reported outcomes for invasive treatments such as BTX-A and SNS. Noninferiority RCTs powered to evaluate the role of DO in predicting treatment response are required.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.

The use of imaging techniques in understanding lower urinary tract (dys)function

The ability to store urine in the bladder and to void at an appropriate time depends on several complex mechanisms in the lower urinary tract (LUT) and its neural control. Normal LUT function requires coordination of the urinary bladder, urethra, pelvic floor, efferent and afferent neurons and specific spinal cord and brain areas. These structures can be visualised using different imaging modalities, such as ultrasound, X-ray and magnetic resonance imaging. The supraspinal neural control of the LUT can be studied using functional brain imaging. During the last two decades, the many technological improvements of these imaging techniques have increased our knowledge of voiding dysfunction. Here, we review the different imaging modalities of the LUT and its neural control and discuss their importance for diagnosing and understanding voiding dysfunction.

Neuromodulation in neurogenic bladder

While neuromodulation is a well-established treatment option for patients with non-neurogenic overactive bladder and urinary retention, its applicability to the neurogenic bladder population has only recently been examined more in depth. In this article we will discuss the outcomes, contraindications, and special considerations of sacral and percutaneous tibial nerve stimulation (PTNS) in patients with neurogenic lower urinary tract dysfunction.