A functional magnetic resonance imaging study of the effect of sacral neuromodulation on brain responses in women with Fowler's syndrome

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.

Functional MRI in neuro-urology: A narrative review

Neuro-imaging has given urologists a new tool to investigate the neural control of the lower urinary tract. Using functional magnetic resonance imaging (fMRI), it is now possible to understand which areas of the brain contribute to the proper function of the storage and voiding of the lower urinary tract. This field of research has evolved from simple anatomical descriptions to elucidating the complex micturition network. A keyword search of the Medline database was conducted by two reviewers for relevant studies from January 1, 2010, to August 2022. Of 2047 peer-reviewed articles, 49 are included in this review. In the last decade, a detailed understanding of the brain-bladder network has been described, elucidating a dedicated network, as well as activated areas in the brainstem, cerebellum, and cortex that share reproducible connectivity patterns. Research has shown that various urological diseases can lead to specific changes in this network and that therapies used by urologists to treat lower urinary tract symptoms (LUTS) are also able to modify neuronal activity. This represents a set of potential new therapeutic targets for the management of the lower urinary tract symptoms (LUTS). fMRI technology has made it possible to identify subgroups of responders to various treatments (biofeedback, anticholinergic, neuromodulation) and predict favourable outcomes. Lastly, this breakthrough understanding of neural control over bladder function has led to treatments that directly target brain regions of interest to improve LUTS. One such example is the use of non-invasive transcranial neuromodulation to improve voiding symptoms in individuals with multiple sclerosis.

Does response to percutaneous tibial nerve stimulation predict similar outcome to sacral nerve stimulation?

AIMS

Percutaneous tibial nerve stimulation (PTNS) is a simple neuromodulation technique to treat an overactive bladder. It is unclear whether the response to PTNS would suggest a similar response to sacral nerve stimulation (SNS), and whether PTNS could be utilized as an alternative test phase for an SNS implant. This study assessed whether PTNS response was a reliable indicator for subsequent SNS trials.

METHODS

We performed a retrospective review of the hospital databases to collect all patients who had PTNS and who subsequently had an SNS trial in two tertiary hospitals from 2014 to 2020. Response to both interventions was assessed. A 50% reduction in overactive symptoms (frequency-volume charts) was considered a positive response. McNemar's tests using exact binomial probability calculations were used. The statistical significance level was set to 0.05.

RESULTS

Twenty-three patients who had PTNS subsequently went on to a trial of SNS. All patients except one had previously poor response to PTNS treatment. Eight of them also failed the SNS trial. However, 15 patients (including the PTNS responder) had a successful SNS trial and proceeded with the second-stage battery implantation. The difference in response rates between the PTNS and SNS trial was statistically significant (p < 0.001).

CONCLUSIONS

Poor response to PTNS does not seem to predict the likelihood of patients responding to SNS. A negative PTNS trial should not preclude a trial of a sacral nerve implant. The predictive factors for good and poor responses will be the subject of a larger study.

Neuroimaging Study Investigating the Supraspinal Control of Lower Urinary Tract Function in Man With Orthotopic Ileal Neobladder

Introduction: Recent studies employing functional imaging methodology have revealed reference brain regions of urinary tract function, namely, the midbrain periaqueductal gray matter, thalamus, and cingulate and prefrontal cortices. The orthotopic ileal neobladder is a desirable method for urinary diversion after radical cystectomy, but its supraspinal control remains unknown. We aimed to evaluate brain activity while maintaining urinary urgency and voluntary urinary control in male subjects with ileal orthotopic neobladders by performing functional MRI (fMRI) during a block design experiment. Materials and Methods: Patients were recruited at the Sun Yat-sen Memorial Hospital of the Sun Yat-sen University from October 2017 to May 2019. Two tasks were performed during fMRI scanning: (1) repeated infusion and withdrawal of sterile saline solution into and out of the neobladder to simulate urgency; and (2) repeated contraction of the pelvic floor muscle with a full neobladder to induce inhibition of micturition since the subjects were asked not to urinate. The obtained data were visualized and statistically analyzed. Results: Sixteen subjects were recruited in the study, and data were obtained from 10 subjects: mean age 60.1 years, average postoperative time 20.2 months, and daytime continence rate 100%. The parahippocampus, frontal lobe, vermis, and anterior cingulate cortex were activated with large bladder volumes, and the thalamus and caudate nucleus were deactivated during voluntary urinary control. Conclusion: A complex supraspinal program is involved during ileal orthotopic neobladder control, which is significantly different from that with normal bladders, in which the original intestine visceral volume sensation is preserved.

Liberation of Serotonin Is Not Unaffected by Acetylcholine in Rat Hippocampus

Purpose

Raised cerebral titers of acetylcholine have notable links with storage symptomatology related to lower urinary tract symptoms. The hippocampus contributes to the normal control of continence in the majority of instances (circuit 3). Owing to synaptic connections with other nerve cells, acetylcholine affects the micturition pathway via the liberation of additional cerebral neurotransmitters. Despite the fact that cerebral serotonin is a key inhibitor of reflex bladder muscle contractions, the influence of acetylcholine on its liberation is poorly delineated. The current research was conducted in order to explore the role of acetylcholine in serotonin liberation from sections of rat hippocampus in order to improve the comprehension of the relationship between cholinergic and serotonergic neurons.

Methods

Hippocampal sections from 6 mature male Sprague-Dawley rats were equilibrated over a 30-minute period in standard incubation medium so as to facilitate [³H]5-hydroxytryptamine (5-HT) uptake. The cerebral neurotransmitter, acetylcholine, was applied to the sections. Aliquots of drained medium solution were utilized in order to quantify the radioactivity associated with [³H]5-HT liberation; any alterations in this parameter were noted.

Results

When judged against the controls, [³H]5-HT liberation from the hippocampal sections remained unaltered following the administration of acetylcholine, implying that this agent has no inhibitory action on this process.

Conclusions

Serotonin liberation from murine hippocampal sections is unaffected by acetylcholine. It is postulated that the bladder micturition reflex responds to acetylcholine through its immediate cholinergic activity rather than by its influence on serotonin release. These pathways are a promising target for the design of de novo therapeutic agents.

Sophisticated regulation of micturition: review of basic neurourology

The neurological regulation of the lower urinary tract can be viewed separately from the perspective of sensory neurons and motor neurons. First, in the receptors of the bladder and urethra of sensory nerves, sensations are transmitted through the periaqueductal gray matter of the midbrain to the cerebral cortex, and the cerebrum goes through the process of decision-making. Motor neurons are divided into upper motor neurons (UMNs) and lower motor neurons (LMNs). UMNs coordinate storage and micturition in the brain stem so that synergic voiding can occur. LMNs facilitate muscle contractions in the spinal cord. The muscles involved in urinary storage and micturition are innervated by the somatic branches of sympathetic, parasympathetic, and peripheral nerves. Sympathetic nerves are responsible for contractions of urethral smooth muscles, while parasympathetic nerves originate from S2–S4 and are in charge of contractions of the bladder muscle. Somatic nerves originate from the motor neurons in Onuf’s nucleus, which is a specific part of somatic nerves. In this review, we will investigate the structures of the nervous systems related to the lower urinary tract and the regulatory system of innervation for the urinary storage and micturition and discuss the clinical significance and future prospects of neurourological research.

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.

Transcutaneous Electrical Nerve Stimulation and Percutaneous Tibial Nerve Stimulation to Treat Idiopathic Nonobstructive Urinary Retention: A Systematic Review

CONTEXT

Transcutaneous electrical nerve stimulation (TENS) and percutaneous tibial nerve stimulation (PTNS) provide minimally invasive ways to treat idiopathic nonobstructive urinary retention (NOUR).

OBJECTIVE

To assess the efficacy of TENS and PTNS for treating idiopathic NOUR.

EVIDENCE ACQUISITION

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Embase, Medline, Web of Science Core Collection, and the Cochrane CENTRAL register of trials were searched for all relevant publications until April 2020.

EVIDENCE SYNTHESIS

A total of 3307 records were screened based on the title and abstract. Eight studies met the inclusion criteria and none of the exclusion criteria. Five studies, all from the same group, reported the efficacy of PTNS and two that of TENS in adults with idiopathic NOUR. One study reported the efficacy of TENS in children with idiopathic NOUR. Objective success was defined as a ≥50% decrease in the number of catheterizations per 24 h or in the total catheterized volume in 24 h. The objective success rate of PTNS ranged from 25% to 41%. Subjective success was defined as the patient's request for continued chronic treatment with PTNS, and ranged from 46.7% to 59%. Eighty percent of women who underwent transvaginal stimulation reported an improvement such as a stronger stream when voiding. TENS in children reduced postvoid residual and urinary tract infections.

CONCLUSIONS

The efficacy of TENS and PTNS in the treatment of idiopathic NOUR is limited and should be verified in larger randomized studies before application in clinical practice.

PATIENT SUMMARY

The outcomes of transcutaneous electrical nerve stimulation and percutaneous tibial nerve stimulation for the treatment of urinary retention of unknown origin were reviewed. Whether these treatments are superior to other treatments could not be established.

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.

Brain activation patterns of female multiple sclerosis patients with voiding dysfunction

AIMS

We compared brain activation patterns between female multiple sclerosis (MS) patients with voiding dysfunction (VD) and those without. We aim to expand current knowledge of supraspinal correlates of voiding initiation within a cohort of female MS patients with and without VD.

MATERIALS AND METHODS

Twenty-eight ambulatory female MS patients with stable disease and lower urinary tract dysfunction were recruited for this study. Subjects were divided into group 1, without VD (n = 14), and group 2, with VD (n = 14), defined as postvoid residual urine of ≥40% of maximum cystometric capacity or need for self-catheterization. We recorded brain activity via functional magnetic resonance imaging (fMRI) with simultaneous urodynamic testing. Average fMRI activation maps (the Student t test) were created for both groups, and areas of significant activation were identified (P < .05). A priori regions of interest (ROIs), identified by prior meta-analysis to be involved in voiding, were selected.

RESULTS

Group-averaged blood-oxygen level-dependent (BOLD) activation maps demonstrated significant differences between groups 1 and 2 during initiation of voiding with group 2 showing significantly lower levels of activation in all ROIs except for the left cerebellum and right cingulate gyrus. Interestingly, group 2 displayed negative BOLD signals, while group 1 displayed positive signals in the right and left pontine micturition center, right periaqueductal gray, left thalamus, and left cingulate gyrus. The activation map of group 1 was similar to healthy controls.

CONCLUSIONS

Our results support the hypothesis that distinct supraspinal activation patterns exist between female MS patients with VD and those without.

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.

Psychological comorbidities and functional neurological disorders in women with idiopathic urinary retention: International Consultation on Incontinence Research Society (ICI-RS) 2019

AIMS

Chronic urinary retention occurring in young women is poorly understood and a cause may not be found in a majority of cases. Different psychological comorbidities and functional neurological symptom disorders (FNDs) have been reported; however, these have been poorly explored.

METHODS

At the International Consultation on Incontinence Research Society meeting in 2019, a panel of clinicians generated a proposal to explore the relationship between psychological comorbidities, FNDs, and urinary retention in women with chronic idiopathic urinary retention.

RESULTS

Psychological comorbidities such as depression and anxiety, and FNDs such as leg weakness and loss of consciousness, have been reported in women with idiopathic urinary retention. Individuals react differently to physical and emotional stressors, and experimental models have demonstrated a relationship between the stress response and developing urinary retention. Trauma, particularly sexual trauma, may be a shared risk factor for developing psychological comorbidities and urinary retention. Children with voiding postponement often suffer from psychological comorbidities and behavioral disturbances; however, there is no evidence to suggest that this progresses to urinary retention in adulthood. "Psychogenic urinary retention" has been described in the urology and psychiatry literature in the past, and anecdotal cases of successful voiding following psychotherapy have been reported, though the true pathophysiology of this entity is uncertain.

CONCLUSION

Psychological and functional disorder comorbidities are reported in women with chronic urinary retention. The nature of the association between urinary retention and functional neurological disorder comorbidities needs to be further explored in terms of a disorder of bladder-brain interaction.

Neuroscience: A New Golden Age for Neurourology

The pons contains neurons that control urinary bladder function. Using the modern tools of neurobiology, new studies reveal a heterogeneous population of neurons which interact with higher centers and the sacral and lumbar spinal cord to coordinate complex voiding behaviors.

Neuromodulation - a therapeutic option for refractory overactive bladder. A recent literature review

Overactive bladder (OAB) affects approximately 17% of the population. The treatment of this clinical condition is challenging, especially when conservative therapy is not effective. There are limited options for the treatment of recurrent OAB. Neuromodulation has taken a significant place in the therapy of recalcitrant lower urinary tract dysfunctions over the past 20 years. The aim of this study was to review the literature evaluating the different forms of neuromodulation in various urological clinical conditions and to show the future prospects of this treatment method. Further studies are necessary to determine the effectiveness of neuromodulation and to identify the prognostic factors of therapeutic success. This could be helpful in the selection of patients who will be most likely to respond positively to the treatment.

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

Higher Neural Correlates in Patients with Multiple Sclerosis and Neurogenic Overactive Bladder Following Treatment with Intradetrusor Injection of OnabotulinumtoxinA

PURPOSE

OnabotulinumtoxinA is a well described treatment of neurogenic overactive bladder. While motor effects on the detrusor muscle have been extensively studied, the sensory effects have not. The aim of this study was to evaluate the impact of intradetrusor onabotulinumtoxinA injection on brain activity in female patients with multiple sclerosis and neurogenic overactive bladder.

MATERIALS AND METHODS

We prospectively studied 12 women with stable multiple sclerosis and neurogenic overactive bladder using concurrent functional magnetic resonance imaging and urodynamic studies prior to and 6 to 10 weeks following onabotulinumtoxinA injection. Individual functional magnetic resonance imaging activation maps at the time of strong urgency were averaged before and after onabotulinumtoxinA injection where areas of significant activation were identified.

RESULTS

After onabotulinumtoxinA injection functional magnetic resonance imaging activation increased in the right cingulate body (p = 0.0012), the left posterior cingulate (p = 0.02), the left anterior cingulate (p = 0.0015), the right prefrontal cortex (p = 0.0015), the insula (p = 0.0138) and the pons micturition center (p = 0.05). Sparse areas showed decreased activity, including the left cerebellum (p = 0.001), the left fusiform gyrus (p = 0.065) and the bilateral lentiform nucleus (p = 0.026).

CONCLUSIONS

Intradetrusor injection of onabotulinumtoxinA appeared to increase the activity of most brain regions known to be involved in the sensation and process of urinary urgency in female patients with multiple sclerosis and neurogenic overactive bladder. To our knowledge this is the first study of its kind to evaluate the possible effects of onabotulinumtoxinA at the human brain level where sensory awareness is located. This activation pattern may be used to further phenotype patients to optimize therapy or determine the sensory effects of onabotulinumtoxinA beyond the bladder.

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).

Reliability of supraspinal correlates to lower urinary tract stimulation in healthy participants - A fMRI study

Previous functional neuroimaging studies provided evidence for a specific supraspinal network involved in lower urinary tract (LUT) control. However, data on the reliability of blood oxygenation level-dependent (BOLD) signal changes during LUT task-related functional magnetic resonance imaging (fMRI) across separate measurements are lacking. Proof of the latter is crucial to evaluate whether fMRI can be used to assess supraspinal responses to LUT treatments. Therefore, we prospectively assessed task-specific supraspinal responses from 20 healthy participants undergoing two fMRI measurements (test-retest) within 5-8 weeks. The fMRI measurements, conducted in a 3T magnetic resonance (MR) scanner, comprised a block design of repetitive bladder filling and drainage using an automated MR-compatible and MR-synchronized infusion-drainage device. Following transurethral catheterization and bladder pre-filling with body warm saline until participants perceived a persistent desire to void (START condition), fMRI was recorded during repetitive blocks (each 15 s) of INFUSION and WITHDRAWAL of 100 mL body warm saline into respectively from the bladder. BOLD signal changes were calculated for INFUSION minus START. In addition to whole brain analysis, we assessed BOLD signal changes within multiple 'a priori' region of interest (ROI), i.e. brain areas known to be involved in the LUT control from previous literature. To evaluate reliability of the fMRI results between visits, we applied different types of analyses: coefficient of variation (CV), intraclass correlation coefficient (ICC), Sørensen-Dice index, Bland-Altman method, and block-wise BOLD signal comparison. All participants completed the study without adverse events. The desire to void was rated significantly higher for INFUSION compared to START or WITHDRAWAL at both measurements without any effect of visit. At whole brain level, significant (p < 0.05, cluster corrected, k ≥ 41 voxels) BOLD signal changes were found for the contrast INFUSION compared to START in several brain areas. Overlap of activation maps from both measurements were observed in the orbitofrontal cortex, insula, ventrolateral prefrontal cortex (VLPFC), and inferior parietal lobe. The two highest ICCs, based on a ROI's mean beta weight, were 0.55 (right insular cortex) and 0.47 (VLPFC). Spatial congruency (Sørensen-Dice index) of all voxels within each ROI between measurements was highest in the insular cortex (left 0.55, right 0.44). In addition, the mean beta weight of the right insula and right VLPFC demonstrated the lowest CV and narrowest Bland and Altman 95% limits of agreement. In conclusion, the right insula and right VLPFC were revealed as the two most reliable task-specific ROIs using our automated, MR-synchronized protocol. Achieving high reliability using a viscero-sensory/interoceptive task such as repetitive bladder filling remains challenging and further endeavour is highly warranted to better understand which factors influence fMRI outcomes and finally to assess LUT treatment effects on the supraspinal level.

Chronic Urinary Retention due to Fowler's Syndrome

Fowler's syndrome (FS) is a rare cause of chronic urinary retention in teenage girls and young women. We present a case of a 14-year-old girl who presented at our hospital 2 weeks after uncomplicated laparoscopic appendectomy. The girl complained of reduced urinary frequency and prolonged micturition time. Following an acute cystitis 2 months later, she completely lost her ability to void. A comprehensive set of investigations to assess the cause of her urinary retention including a cerebral and spinal magnetic resonance imaging (MRI), and videourodynamics were performed. The diagnostic workup revealed polycystic ovaries and an asensitive and hypotonic bladder with capacity up to 1200 mL and high maximum urethral pressure of 120 cm of water. She did not tolerate clean intermittent catheterization; therefore, a suprapubic catheter was placed. Under this treatment, she suffered recurrent urinary tract infections. Two years later, she was diagnosed with FS on the basis of the medical history, clinical symptoms, and urodynamic findings. Finally, the implantation of a S3 neurostimulator restored her ability to void.

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.

The efficacy of botulinum toxin A and sacral neuromodulation in the management of interstitial cystitis (IC)/bladder pain syndrome (BPS), what do we know? ICI-RS 2017 think thank, Bristol

AIMS

This manuscript aims to address the evidence availale in the literature on the efficacy of Botulinum Toxin A (BoNT-A) and sacral neuromodulation (SNM) in patients suffering from Interstitial Cystitis (IC)/BPS and propose further research to identify mechanisms of action and establish the clinical efficacy of either therapy.

METHODS

At the International Consultation on Incontinence-Research Society (ICI-RS) in 2017, a panel of Functional Urologists and Urogynaecologists participated in a Think Tank (TT) discussing the management of IC/BPS by BoNT-A and SNM, using available data from both PubMed and Medicine literature searches.

RESULTS

The role of BoNT-A and SNM in the treatment of IC/BPS are discussed and mechanisms of actions are proposed. Despite the available randomized trial data on the effect of intravesical BoNT-A treatment on symptoms of IC/BPS, a consistent conclusion of a positive effect cannot be drawn at the moment, as the published studies are small and heterogeneous in design. There is substantive evidence for the positive effects of SNM on symptoms of IC/BPS patients however, during patient selection, it is important to distinguish the degree and the location of pain in order to tailor the best therapy to the right patients.

CONCLUSIONS

Both intravesical BoNT-A treatment and SNM have been shown to have positive effects in patients with IC/BPS. However, firm conclusions cannot yet be drawn. Patient-reported outcomes and quality of life should be assessed in addition to urinary and pain symptoms. Since current treatments mainly focus on symptomatic relief, future research should also focus on clarifying the pathogenic mechanisms involved in IC/BPS.

New frontiers in molecular and imaging research on evaluation and diagnosis of bladder outlet obstruction in women

Purpose

Diagnosis of bladder outlet obstruction (BOO) often presents a challenge in female patients. Traditional diagnostic elements such as symptom history and urodynamic data are rarely clear cut in women. Therefore, we sought to review the current literature on diagnosis of female BOO, focusing on new frontiers in the realm of molecular markers and imaging modalities.

Recent Findings

In addition to fluoroscopy in the setting of videourodynamics, ultrasound and MRI can augment the diagnosis and aid in therapeutic planning in certain etiologies of female BOO. Furthermore, multiple potential biomarkers (i.e. nerve growth factor, prostaglandins, ATP) that have been studied in correlation to BOO in animal models as well as human subjects hold promise for diagnostic applications.

Summary

These novel techniques may augment standard clinical and urodynamic evaluation of BOO in females. Future directions include further studies of each of these biomarkers in female patients with BOO compared to normal controls to test their feasibility as potential screening tools.

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.

Non-neurogenic Chronic Urinary Retention: What Are We Treating?

PURPOSE OF REVIEW

This review examines current terminology used to define non-neurogenic chronic urinary retention (CUR), describes the pathophysiology of urinary retention, and highlights contemporary diagnostic and treatment algorithms.

RECENT FINDINGS

There is no standardized definition for the condition, but volumes >300 ml are commonly used to describe CUR. It is a clinical diagnosis which does not require urodynamics. Pathophysiologic causes of CUR be from myogenic, neurogenic, bladder outlet obstruction, or a combination of these sources. Treatment algorithms recommend stratifying patients with chronic urinary retention by risk and by symptoms before initiating treatment. Common CUR outcome endpoints need to be better utilized so that treatment modalities can be compared. Non-neurogenic CUR is a heterogeneous condition that has multiple definitions, underlying physiologies, and possible endpoints. Standardization is needed to better understand and treat CUR.

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.

Clinical utility of neurostimulation devices in the treatment of overactive bladder: current perspectives

Objectives

This review describes the evidence from established and experimental therapies that use electrical nerve stimulation to treat lower urinary tract dysfunction.

Methods

Clinical studies on established treatments such as percutaneous posterior tibial nerve stimulation (P-PTNS), transcutaneous electrical nerve stimulation (TENS), sacral nerve stimulation (SNS) and sacral anterior root stimulation (SARS) are evaluated. In addition, clinical evidence from experimental therapies such as dorsal genital nerve (DGN) stimulation, pudendal nerve stimulation, magnetic nerve stimulation and ankle implants for tibial nerve stimulation are evaluated.

Results

SNS and P-PTNS have been investigated with high-quality studies that have shown proven efficacy for the treatment for overactive bladder (OAB). SARS has proven evidence-based efficacy in spinal cord patients and increases the quality of life. TENS seems inferior to other OAB treatments such as SNS and P-PTNS but is noninvasive and applicable for ambulant therapy. Results from studies on experimental therapies such as pudendal nerve stimulation seem promising but need larger study cohorts to prove efficacy.

Conclusion

Neurostimulation therapies have proven efficacy for bladder dysfunction in patients who are refractory to other therapies.

Significance

Refinement of neurostimulation therapies is possible. The aim should be to make the treatments less invasive, more durable and more effective for the treatment of lower urinary tract dysfunction.

Technical challenges and safety of magnetic resonance imaging with in situ neuromodulation from spine to brain

PURPOSE

This review summarises the need for MRI with in situ neuromodulation, the key safety challenges and how they may be mitigated, and surveys the current status of MRI safety for the main categories of neuro-stimulation device, including deep brain stimulation, vagus nerve stimulation, sacral neuromodulation, spinal cord stimulation systems, and cochlear implants.

REVIEW SUMMARY

When neuro-stimulator systems are introduced into the MRI environment a number of hazards arise with potential for patient harm, in particular the risk of thermal injury due to MRI-induced heating. For many devices however, safe MRI conditions can be determined, and MRI safely performed, albeit with possible compromise in anatomical coverage, image quality or extended acquisition time.

CONCLUSIONS

The increasing availability of devices conditional for 3 T MRI, whole-body transmit imaging, and imaging in the on-stimulation condition, will be of significant benefit to the growing population of patients benefitting from neuromodulation therapy, and open up new opportunities for functional imaging research.

Female Bladder Outlet Obstruction

The non-specific symptoms the patients express upon the presentation of female bladder outlet obstruction make it a challenge to diagnose. There are subtle differences between the obstructed patient and those whose bladders are underactive and/or fail to mount a detrusor contraction. These disparities can be extracted through a thorough history and examination. At times, the clinician may utilize nomograms, non-invasive uroflow, and urodynamics with the addition of fluoroscopy to establish the diagnosis of obstruction. Management of the obstruction depends on the nature of the condition, whether functional or anatomical. The increase in the number of sling procedures performed to treat stress urinary incontinence has resulted in a rise in the number of iatrogenic obstructions. The temporal relationship between surgery and obstruction is the key to identifying the problem.

Overactive bladder in children

Overactive bladder (OAB) is a ubiquitous syndrome that is defined by urinary urgency with, or without urinary incontinence. OAB is observed in all parts of the world, with a prevalence of 5-12% in children (5-10 years of age) and a prevalence of 0.5% in older adolescents (16-18 years of age). Published data indicate that around a third of children with OAB are likely to become adults with similar complaints. Studies in children and in adults with OAB indicate that these individuals are more likely to also have anxiety, depression and attention deficit problems, and that appropriate treatment of these comorbidities can often improve the patient's OAB symptoms. Furthermore, data from twin studies and familial surveys seem to indicate a genetic component of OAB. Pharmacological treatments of OAB in children have improved in the past 5 years, moving beyond anticholinergic agents and including the off-label use of α-blockers, β3-agonists and intravesical botulinum toxin. Use of several different electrical stimulation techniques is also effective, both as first-line treatments, and for patients with treatment-refractory symptoms. Overall the outlook of children with OAB seems to be improving, with a greater understanding of the pathophysiology of this syndrome. Treatment modalities that target the source of the underlying problem, especially in children, are likely to provide the best patient outcomes.

Electrical Stimulation of the Spinal Dorsal Root Inhibits Reflex Bladder Contraction and External Urethra Sphincter Activity: Is This How Sacral Neuromodulation Works?

INTRODUCTION

Using a rat model, we aimed to confirm the inhibitory effect of dorsal spinal root (afferent) stimulation and test if bilateral stimulation is more effective than unilateral stimulation. External urethral sphincter (EUS) electromyography (EMG) is also assessed in conjunction with cystometrogram.

MATERIALS AND METHODS

Eighteen female Sprague-Dawley rats were tested following urethane anesthesia. Via urethral catheterization, the bladder was infused with normal saline to evoke rhythmic bladder reflex contractions (BRC). L6 spinal nerves were isolated and stimulated.

RESULTS

L6 stimulation was effective in inhibiting BRC. L6 bilateral dorsal root (DR) stimulation of 50% intensity was required to cause inhibition as compared to unilateral stimulation. In EUS EMG recordings, there was a strong association between EUS EMG activities and bladder contraction. When the bladder contraction was inhibited effectively by L6 DR stimulation, a considerable reduction was also found in the EUS EMG activities.

CONCLUSIONS

L6 DR stimulation abolished BRC in our rat model. Bilateral L6 DR stimulation produced a 50% reduction in stimulation intensity, providing a similar BRC block. Abolishing BRC also appeared to coincide with a reduction in EUS EMG, implicating that sacral neuromodulation might act centrally, at least rostrally at the T8-9 spinal level.

Urologic symptoms and functional neurologic disorders

The term functional urologic disorders covers a wide range of conditions related broadly to altered function rather than structure of the lower urinary tract, mainly of impaired urine voiding or storage. Confusingly, for a neurologic readership, these disorders of function may often be due to a urologic, gynecologic, or neurologic cause. However, there is a subset of functional urologic disorders where the cause remains uncertain and, in this chapter, we describe the clinical features of these disorders in turn: psychogenic urinary retention; Fowler's syndrome; paruresis (shy-bladder syndrome); dysfunctional voiding; idiopathic overactive bladder, and interstitial cystitis/bladder pain syndrome. Some of these overlap in terms of symptoms, but have become historically separated. Psychogenic urinary retention in particular has now largely been abandoned as a concept, in part because of the finding of specific urethral electromyogram findings in patients with this symptom now described as having Fowler's syndrome, and their successful treatment with sacral neurostimulation. In this chapter we review the poorly researched interface between these "idiopathic" functional urologic disorders and other functional disorders (e.g., irritable-bowel syndrome, fibromyalgia) as well as specifically functional neurologic disorders. We conclude that there may be a relationship and overlap between them and that this requires further research, especially in those idiopathic functional urologic disorders which involve disorders of the urethral sphincter (i.e., voluntary muscle).

Underactive Bladder in Older Adults

Overactive bladder is one of the most common bladder problems, but an estimated 20 million Americans have underactive bladder (UAB), which makes going to the bathroom difficult, increases the risk of urinary tract infections, and even leads to institutionalization. This article provides an overview of UAB in older adults, and discusses the prevalence, predisposing factors, cause, clinical investigations, and treatments. At present, there is no effective therapy for UAB. A great deal of work still needs to be done on understanding the pathogenesis and the development of effective therapies.

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.

Functional imaging of structures involved in neural control of the lower urinary tract

Recent functional brain imaging studies, building on earlier observations, suggest a working model of brain control of the lower urinary tract. It comprises a few cerebral neural circuits that, during the storage phase, act on the midbrain periaqueductal gray to inhibit the long-loop, spinobulbospinal voiding reflex, thus promoting continence. Circuit 1, centered on the medial prefrontal cortex, appears to be concerned with conscious control of both continence and voiding. Circuit 2, centered on the dorsal anterior cingulate (midcingulate) and supplementary motor area, is concerned with emotional aspects of bladder control: desire to void or urgency with concomitant urethral sphincter activation to delay leakage. A subcortical circuit 3 has been less well studied. Circuit 1 is bilateral with a right-sided preference. Scattered studies of the connectivity of the control network suggest that white-matter damage may contribute to urinary incontinence. A few studies confirm that isolated cerebral lesions, if in the medial prefrontal cortex or its connecting pathways, may lead to incontinence. Lower urinary tract dysfunction in other neurologic diseases (normal-pressure hydrocephalus, Parkinson's disease, and multiple systems atrophy) appears consistent with the working model, and even spinal or peripheral lesions have central effects. However, this model omits the contributions of brain regions already observed in some imaging studies and therefore is certainly oversimplified.

Comprehensive urodynamics: Being devoted to clinical urologic practice

As a combined electrophysiological system for evaluating the lower urinary tract (LUT), comprehensive urodynamics (UDS) aims at duplicating patient’s micturition process, either normal or abnormal, and further seeking for possible causative origin, either neurogenic or non-neurogenic, in order to guide treatment. Through thorough analysis, some so-called cut-off values, for example, bladder outlet obstruction (BOO) degree or dyssynergic degree between the detrusor and sphincter, could be gained; however, in most cases, their qualitative description, such as stress urinary incontinence, idiopathic detrusor underactivity (DUA), detrusor overactivity (IDO), low compliance, and idiopathic sphincter overactivity (ISO), is more preferable and important. In aged neurologically intact male patients with symptoms of the LUT (LUTS) including benign prostatic hyperplasia, a combined UDS system, which coupled BOO with compliance, was constructed. The patients may be categorized into one of the seven subgroups, including equivocal or mild BOO with sphincter synergia with or without IDO (pattern A), equivocal or mild BOO with ISO (B), classic BOO with sphincter synergia (C) or ISO (D), BOO with only low compliance (E), BOO with both DUA and low compliance (F), and potential BOO with DUA (G). This new system can be used to optimize diagnosis and treatment according to a derived guideline diagram.

The effects of sacral nerve stimulation on continence are temporarily maintained after turning the stimulator off

AIM

Sacral nerve stimulation is an effective treatment for urinary and faecal incontinence even though its mechanism of action is uncertain. Central nervous system involvement by 'setting-up' neurological mechanisms appointed to control pelvic function has been hypothesized. The study aimed to evaluate whether the effects of long-term sacral nerve stimulation are memorized and therefore maintained after switching off the stimulator.

METHOD

Patients having sacral nerve stimulation for faecal and/or urinary incontinence for at least 1 year had the stimulator turned off and the results monitored. Data recorded with the stimulator off were compared with post-implant data. If symptoms recurred the stimulator was switched back on. Nineteen patients entered the study. Fourteen had faecal and/or urinary incontinence and five had faecal incontinence alone. The symptoms were assessed by means of a bowel function diary and dedicated questionnaire.

RESULTS

In 10 patients symptoms recurred at different intervals after a median off period of 3.4 months with a probability of symptom relapse of 55%. The Fecal Incontinence Quality of Life (FIQL) score did not show any significant difference in nine patients with the stimulator off for at least 1 year. No factors predictive of symptom recurrence were identified although an idiopathic aetiology, severity of disease and urinary incontinence had higher hazard ratios. During the off period, none of the scores and episodes of incontinence showed significant changes compared with the on period.

CONCLUSION

The effects of sacral nerve stimulation on faecal and urinary incontinence were maintained in about half of patients after switching the stimulator off, but in some symptoms returned after different periods of time. The data shed new light on possible effects of sacral nerve stimulation on brain neuroplasticity in the control of continence.

Brain responses to bladder filling in older women without urgency incontinence

AIMS

To investigate normal brain responses to bladder filling, especially when there is little or no sensation as in much of daily life.

METHODS

We performed an functional magnetic resonance imaging (fMRI) study of brain responses to bladder filling in normal female subjects, evoked by infusion and withdrawal of fluid in and out of the bladder. Using the contrast (infusion-withdrawal), we imaged brain activity at small bladder volumes with weak filling sensation and also with full bladder and strong desire to void.

RESULTS

Eleven women, average age 65 years (range: 60-71 years) were included. With full bladder and strong desire to void, filling provoked a well-known pattern of activation near the right insula and (as a trend) in the dorsal anterior cingulate cortex and supplementary motor area. There was no significant deactivation. With small bladder volume filling provoked widespread apparent deactivation and no significant activation. Apparent deactivation was associated with increased fMRI signal during withdrawal rather than decrease during infusion, suggesting artifact. A correction for global changes in cerebral blood flow eliminated it and revealed significant subcortical activation, although none in frontal or parietal cortex.

CONCLUSIONS

In older women with normal bladder function, infusion into an already full bladder resulted in strong sensation and brain activation near the insula and in the dorsal anterior cingulate/supplementary motor complex. With near-empty bladder and little sensation, the situation during much of daily life, these cortical areas were not detectably activated, but activation in midbrain and parahippocampal regions presumably indicated unconscious monitoring of ascending bladder signals.

Functional bladder problems in children: pathophysiology, diagnosis, and treatment

Functional lower urinary tract problems, bladder and bowel problems, or dysfunctional elimination syndrome are all terms that describe the common array of symptoms that include overactive bladder syndrome, voiding postponement, stress incontinence, giggle incontinence, and dysfunctional voiding in children. This article discusses the nomenclature and looks at the pathophysiology of functional bladder disorders from a different perspective than has been the norm in the past. Some standard medical treatments as well as some newer forms of treatment are outlined. Treatment algorithms for urinary frequency and urinary incontinence have been created to help the practitioner manage the patient.