Incomplete bladder emptying in patients with stroke: is detrusor external sphincter dyssynergia a potential cause?

Lower urinary tract dysfunction in the central nervous system neurogenic bladder and the real-life treatment outcome of botulinum toxin A

Neurogenic lower urinary tract dysfunction (NLUTD) is common in patients with central nervous system (CNS) lesions. Cases of cerebrovascular accidents (CVA), Parkinson's disease, dementia, and other intracranial lesions develop poor bladder control with or without urinary difficulty due to loss of cortical perception of bladder filling sensation and poor coordination of urethral sphincter relaxation during reflex micturition. Patients with CNS lesions usually have overactive bladder (OAB) symptoms, including urgency, frequency, incontinence, voiding symptoms of dysuria, large postvoid residual volume, and retention. In elderly patients with severe CNS disease the OAB symptoms are usually difficult to adequately relieve by medical treatment, and thus, their quality of life is greatly. Botulinum toxin A (BoNT-A) is currently licensed and has been applied in patients with idiopathic and neurogenic OAB due to spinal cord injury or multiple sclerosis. However, the application of BoNT-A in the treatment of urinary incontinence due to NLUTD in chronic CNS lesions has not been well-documented. Although cohort studies and case series support BoNT-A treatment for neurogenic OAB, chronic urine retention after intravesical BoNT-A injection for OAB and exacerbated urinary incontinence after urethral BoNT-A injection for voiding dysfunction have greatly limited its application among patients with NLUTD due to CNS lesions. This article reviews the pathophysiology and clinical characteristics of NLUTD in patients with CNS lesions and the clinical effects and adverse events of BoNT-A injection for patients with NLUTD. A flowchart was created to outline the patient selection and treatment strategy for neurogenic OAB.

Detrusor Sphincter Dyssynergia

Detrusor sphincter dyssynergia (DSD) is defined as a detrusor contraction concurrent with an involuntary contraction of the urethral and/or periurethral striated muscles typically occurring in a patient with a spinal cord lesion above the sacral cord. Consequently, high urethral closure pressures during the detrusor contraction leads to high intravesical voiding pressure and large postvoid residuals, which can lead to significant complications in up to 50% of patients if DSD is not treated and followed-up regularly. DSD treatment options are centered around symptomatic management rather that addressing the underlying causative mechanisms.

Comparative Effectiveness of Two Models of Point-of-Care Ultrasound for Detection of Post-Void Residual Urine during Acute Ischemic Stroke: Preliminary Findings of Real-World Clinical Application

We conducted a comparative study of two models of point-of-care ultrasound devices for measuring post-void residual urine (PVRU). We prospectively enrolled 55 stroke inpatients who underwent both real-time B-mode ultrasound (Device A) and automated three-dimensional (3D) scanning ultrasound (Device B), with a total of 108 measurements. The median PVRU volume of Device B was 40 mL larger than that of Device A. The PVRU difference between the devices was positively and linearly correlated with PVRU. The correlation of PVRU volume between the devices was strong, but the agreement level was only moderate. Measurement deviations were observed in 43 (40%) and 11 (10%) measurements with Device B and Device A, respectively. The PVRU volume was low in spherical bladder shapes but sequentially increased in triangular, undefined, ellipsoid, and cuboid bladder shapes. Further comparison of 60 sets of PVRU without measurement deviations revealed higher agreements between the devices at correction coefficients of 0.52, 0.66, and 0.81 for PVRU volumes of <100, 100-200, and >200 mL, respectively. The automated 3D scanning ultrasound is more convenient for learning and scanning, but it exhibits larger measurement deviations. Real-time B-mode ultrasound accurately visualizes the urinary bladder but tends to underestimate the urinary bladder when the PVRU volume is large. Hence, real-time B-mode ultrasound with automated PVRU-based adjustment of calculation formulas may be a better solution for estimating bladder volume.

Acupuncture improves the residual urine volume of bladder of middle age patients with urinary retention post-stroke: A protocol for systematic review and meta analysis

BACKGROUND

There are 15 million new cases of stroke every year in the world, 65% of which have dysuria in the early stage of stroke, which seriously affects the quality of life of stroke patients. The purpose of this study is to evaluate the results of randomized controlled trials to determine whether acupuncture can improve the residual urine volume of the bladder in middle age patients with urinary retention post-stroke.

METHODS

Eight databases, including China National Knowledge Infrastructure, Chinese Scientific Journal Database, Cochrane Central Register of Controlled Trials, Embase, MEDLINE, PubMed, Wanfang Database, and Web of Science, will be searched using English and Chinese search strategies. In addition, manual retrieval of research papers, conference papers, ongoing experiments, internal reports, etc, will supplement electronic retrieval. All eligible studies published on or before October 1, 2022 will be selected. To enhance the effectiveness of the study, only clinical randomized controlled trials related to the use of manual acupuncture for the treatment of urinary retention post-stroke will be included.

CONCLUSION

The residual urine volume of bladder will be the primary outcome measure, whereas the Clinical efficiency will be the secondary outcomes. Side effects and adverse events will be included as safety evaluations. To ensure the quality of the systematic evaluation, study selection, data extraction, and quality assessment will be independently performed by two authors, whereas a third author will resolve any disagreement.

Surgical outcome of male patients with chronic central nervous system disorders and voiding dysfunction due to bladder outlet obstruction

PURPOSE

Voiding dysfunction is common in patients with chronic central nervous system (CNS) diseases and has great impact on quality of life. Patients with chronic CNS disorders might have concomitant detrusor overactivity, detrusor underactivity, and voiding dysfunction. Although bladder outlet surgeries could relieve bladder outlet obstruction (BOO), patients might have persistent or exacerbated storage symptoms. This study investigated surgical outcome of patients with chronic CNS disorders after bladder outlet surgery.

METHODS

A total of 63 male patients with cerebrovascular accident (CVA, n = 44), Parkinson's disease (PD, n = 11), and early-stage dementia (n = 8), had received bladder outlet surgery after videourodynamic proven BOO refractory to medical treatment. The preoperative and postoperative lower urinary tract symptoms (LUTS) and uroflowmetry parameters were assessed. If the storage symptom subscore decreased or increased by 1, the outcome was considered improved or exacerbated after treatment. When patients had improvement in maximum flow rate (Qmax) and voiding efficiency (VE) and decreased voiding symptom subscore, they were considered having improvement of voiding dysfunction.

RESULTS

The mean age was 71.1 ± 9.8 years and mean duration from diagnosis of BOO to surgical intervention was 15.1 ± 25.0 months. Overall, there was significant improvement in voiding LUTS and urinary retention after surgery. The post-void residual volume (PVR), corrected Qmax (cQmax), and VE significantly improved after surgery. In subgroup analysis, although voiding symptoms improved in CVA patients, urgency and exacerbated urgency incontinence persisted after surgery. In PD patients, there was improvement in voiding condition such as PVR, cQmax and VE, but the storage symptoms did not change after surgery. Patients with dementia had no improvement both in storage and voiding symptoms.

CONCLUSIONS

Bladder outlet surgeries are effective to relieve voiding dysfunction in patients with CVA and PD, but have little effect on storage LUTS in patients with chronic brain lesions.

Video-urodynamic characteristics of lower urinary tract dysfunctions in patients with chronic brain disorders

AIMS

Lower urinary tract dysfunction (LUTD) is common in patients with chronic brain disorders. This study investigated the video-urodynamic study (VUDS) findings of LUTD in patients with chronic brain disorders, including cerebrovascular accident (CVA), Parkinson's disease (PD), and early dementia.

METHODS

A total of 169 patients with a history of chronic brain disorders, including 84 with CVA, 55 with PD, and 30 with early dementia were enrolled. All patients had a comprehensive chart review, including brain disorder subtype, the period from diagnosis to VUDS, the VUDS parameters, and final LUTD.

RESULTS

The mean age of patients was 69.2 ± 10.5 years, and the interval from brain insult to VUDS was 61.3 ± 49.7 months. Urodynamic detrusor overactivity (DO) was noted in 73.4% of patients, detrusor underactivity in 10.1%, and detrusor overactivity with detrusor underactivity in 16.6%. Bladder outlet obstruction (BOO) was noted in 60.9% of patients, including bladder neck dysfunction in 21.3%, urethral sphincter dysfunction in 42%, and prostatic obstruction in 10.1% of male patients. Urethral sphincter dysfunction was noted in 60% of patients with PD, 32.1% with CVA, and 36.7% with dementia (p = 0.004). A low mean maximum flow rate increased post-void residual volume, and poor voiding efficiency was common in these patients, without significant differences among the subgroups.

CONCLUSIONS

Real-world VUDSs revealed that patients with chronic brain disorders not only had a high prevalence of DO but also impaired bladder contractility and a high rate of BOO at the level above the bladder neck and urethral sphincter.

Prevalence of Comorbid Spasticity and Urinary Incontinence in Residents of a Long-Term Care Facility

The current study evaluated the prevalence of comorbid spasticity and urinary incontinence (UI) in a long-term care facility. Medical history, presence of UI, and activities of daily living (ADL) dependency were obtained from medical records and Minimum Data Set 3.0. Quality of life was assessed with the EuroQoL-5D-5L (EQ-5D). Comorbid spasticity and UI presented in 29% of participants (14 of 49). Participants with spasticity and UI had higher ADL dependency and lower EQ-5D than participants without both conditions (4.9, 95% confidence interval [CI] [1.6, 80.], p = 0.003; -0.17, 95% CI [-0.33, 0.00], p = 0.044; respectively). More than one half of participants with lower limb spasticity had severe UI, compared to only 10% without lower limb spasticity (relative risk = 5.5; 95% CI [1.9, 15.9]; p = 0.006). Comorbid spasticity and UI may be common in the long-term care setting and negatively associated with ADL and quality of life. Further investigation is needed to confirm these findings. [Journal of Gerontological Nursing, 46(10), 35-42.].

Urinary dysfunction in acute brain injury: A narrative review

The frontal lobe urinary control center is an important regulator of urinary function. Neurologic injury often causes damage or temporary dysfunction of this center and other related urinary control pathways. Little has been reported about this topic in the literature although a majority of neurologic injury patients suffer from some type of urinary dysfunction. In this review, we highlight what is known about urinary dysfunction based on injury type (traumatic brain injury, hemorrhagic stroke, ischemic stroke, subarachnoid hemorrhage, subdural hematoma, and epilepsy). We discuss both clinical and pre-clinical data and pinpoint areas warranting further investigation. In the final section, we provide proposed practice suggestions for managing these patients clinically with the intended goal for refinement in these approaches following further clinical trials.

Portable Bladder Ultrasound Reduces Incidence of Urinary Tract Infection and Shortens Hospital Length of Stay in Patients With Acute Ischemic Stroke

BACKGROUND

Urinary tract infection (UTI) during acute ischemic stroke is associated with a longer hospital length of stay and unfavorable functional outcomes.

OBJECTIVE

We investigated the benefits of portable bladder ultrasound (PBU) scanning during acute ischemic stroke.

METHODS

We retrospectively reviewed patients with acute ischemic stroke from January 2011 to February 2017. Patients were divided into group 1 (PBU not available) and group 2 (PBU available), before or after the split date, April 9, 2014. Portable bladder ultrasound scanning was conducted by nurses to measure postvoid residual urine volume in patients with impaired consciousness and/or dependent ambulation.

RESULTS

In total, 1928 patients were enrolled, of whom 109 (5.7%) had UTI and 901 (46.7%) experienced unfavorable outcomes (modified Rankin scale score ≥ 3). Multivariate analysis revealed that factors that influenced UTI were age of 75 years or older, female gender, initial total National Institutes of Health Stroke Scale (NIHSS) score of 5 or higher, initial NIHSS conscious score of 1 or higher, initial NIHSS leg score of 2 or higher, and urinary catheterization. Factors influencing unfavorable outcomes were similar to those influencing UTI but further comprised UTI. C-statistic for UTI detection was 0.864 for model fitting, including significant factors in logistic regression. Compared with group 1, group 2 had a higher incidence of urinary catheterization (13.1% vs 8.2%), a lower incidence of UTI (4.0% vs 6.9%), and a shorter length of stay (11.9 vs 13.6 days).

CONCLUSIONS

Portable bladder ultrasound scanning reduced the incidence of UTI and shortened length of stay. We suggest routine PBU procedures for patients with acute ischemic stroke who fulfill the AGN3 criteria for a high risk of UTI.

[Neuroanatomical correlates between stroke lesions and urinary disorders: A narrative review]

CONTEXT

Stroke generates diverse urinary disorders, frequent but often under-diagnosed and thus untreated. Even though advances in the comprehension of the physiological voiding control and involved brain areas, the precise correspondence between lesion sites and observed urinary symptoms is not clearly established.

OBJECTIVE

This review aimed to update on this neuroanatomical correlates.

DOCUMENTARY SOURCES

The search focused on articles written in French or English, on PubMed, studying human beings or animals, published between the 1st of January 2000 and the 31st of August 2018 using the following keywords (stroke or hemiplegia) and (urinary incontinence or low urinary tract symptom or retention or overactive bladder or dysuria) and (anatomy or location or localization or area or lesion).

STUDIES SELECTION

The main author selected the most pertinent articles on abstracts and then on full text.

RESULTS

Twelve studies were included in our review. We could not fully confirm the neuroanatomical correlates based on the animal model. Frontoparietal lesions in urinary incontinence, role of the insula in the urinary retention, and systematic but different urinary symptoms in the brain stem lesions are the main findings.

LIMITS

Few studies were included, with varying methodologies and types of population.

CONCLUSION

A few cerebral areas damaged by stroke seem to be linked to certain urinary troubles, but new studies with a higher methodological quality are required to confirm this result.

Therapeutic effect of urethral sphincter onabotulinumtoxinA injection for urethral sphincter hyperactivity

PURPOSE

Urethral sphincter hyperactivity resulting in voiding dysfunction is frequently encountered. Medical treatment might not achieve a satisfactory result. OnabotlinumtoxinA urethral sphincter injection relaxes sphincter tonicity and possibly resumes efficient voiding. This study analyzed the treatment outcomes and predictor for successful onabotulinumtoxinA treatment on these patients.

METHODS

Patients with voiding dysfunction due to urethral sphincter hyperactivity and treated with injections of 100 U onabotulinumtoxinA into the urethral sphincter were retrospectively reviewed. Treatment outcomes were assessed 1 month after injection using the Global Response Assessment and were analyzed by demographic and baseline video-urodynamic characteristics.

RESULTS

Of the 95 patients included, satisfactory outcomes were reported in 58 (61.1%) patients. Treatment outcome was not related to age, gender, or voiding dysfunction subtype. Patients with satisfactory outcomes had a significantly smaller volume at first sensation of filling (P = 0.046), greater detrusor pressure (P = 0.027), higher maximum flow rate (P = 0.017), and smaller post-void residual (P = 0.006). In multivariate analysis, an open bladder neck during voiding was the only predictor for successful outcome (88% in satisfactory outcome, 12% in failure outcome, P < 0.001). Patients with non-neurogenic voiding dysfunction had a significantly longer therapeutic duration than those with neurogenic voiding dysfunction (9.55 ± 4.18 vs 7.44 ± 2.91 months, P = 0.033). Increased urinary incontinence was reported in 18 patients, including 6 with stress urinary incontinence and 12 with urgency urinary incontinence.

CONCLUSION

Subjective improvement was reported in 61.1% of patients with voiding dysfunction due to urethral sphincter hyperactivity after onabotulinumtoxinA urethral sphincter injection. An open bladder neck during voiding at baseline predicts a successful outcome.

Transurethral resection of the prostate achieves favorable outcomes in stroke patients with symptomatic benign prostate hyperplasia

OBJECTIVES

To evaluate the surgical outcomes of stroke patients with symptomatic benign prostatic hyperplasia (BPH) who underwent transurethral resection of the prostate (TURP) and compare the clinical outcomes between patients with stroke and those without stroke receiving this procedure.

METHODS

This retrospective cohort study analyzed claims data collected during the period of 1997-2012 from Taiwan National Health Insurance Research Database. We enrolled 6625 patients who had persistent lower urinary tract symptoms and underwent TURP for BPH. They were categorized into a stroke (n = 577) and nonstroke (n = 6048) group. Patient characteristics, postoperative clinical outcomes, medication records, and medical expenses were compared.

RESULTS

Compared with the stroke group patients, those in the nonstroke group were younger, had fewer comorbidities, and more favorable postoperative clinical outcomes. Nevertheless, TURP achieved favorable outcomes in stroke patients with symptomatic BPH. In the stroke group, the rate of urinary tract infection (UTI) decreased from 34.7% during 1 year preoperatively to 29.8% during 1 year postoperatively (p = .05). The rate of urinary retention (UR) also decreased from 55.5% during 1 year preoperatively to 22.5% during 1 year postoperatively (p = .05). TURP reduced the overall medical expenses of patients with stroke. Annual patient medical expense during 1 year preoperatively, 1 year postoperatively, 2 years postoperatively, and 3 years postoperatively was NT$659,000, NT$646,000, NT$560,000, and NT$599,000, respectively.

CONCLUSIONS

In patients with stroke, TURP reduces the risks of UTI and UR and annual total medical expense.

Video-urodynamic characteristics of non-neurogenic, idiopathic underactive bladder in men - A comparison of men with normal tracing and bladder outlet obstruction

Objective

Underactive bladder is frequently encountered in elderly patients. It may result from detrusor underactivity (DU) or low detrusor contractility due to a urethral sphincter inhibitory effect. This study analyzed the video-urodynamic study (VUDS) characteristics of patients with underactive bladder in a large cohort of men with lower urinary tract symptoms (LUTS).

Methods

Male patients with LUTS who had failed the initial treatment were consecutively enrolled. All patients underwent detailed urological investigations including prostate measurement, free uroflowmetry, post-void residual volume (PVR) measurement, cystoscopy and VUDS. The VUDS characteristics of the men with underactive bladder were analyzed and compared with those of men with bladder outlet obstruction and normal tracing.

Results

A total of 1329 men who underwent VUDS were included in this retrospective analysis. After VUDS, the final diagnosis was DU in 165 patients, poor relaxation of external sphincter (PRES) in 525, bladder outlet obstruction in 501, and normal tracing in 138. VUDS findings in DU patients showed a slowly increased detrusor pressure, intermittent detrusor contractions, or early decline of detrusor contraction, resulting in a low maximum flow rate (Qmax), and large PVR. In comparison with the PRES groups, DU patients were older, had reduced bladder sensation, lower detrusor pressure (Pdet), lower Qmax, larger PVR volume, and lower voiding efficiency. Patients with urodynamic PRES also had low-pressure–low-flow tracings, but their bladder sensation was similar to that with normal tracing. DU patients with very low Pdet also had low detrusor tonicity, and more medical co-morbidities than the other groups did.

Conclusion

Idiopathic underactive bladder in elderly men could be attributed to urodynamic DU and PRES. DU is associated with old age, reduced bladder sensation, low voiding efficiency, and medical co-morbidities.

Current consensus and controversy on the treatment of male lower urinary tract symptoms/benign prostatic hyperplasia

Lower urinary tract symptoms (LUTS) are highly prevalent in men and increase with age. Because LUTS are common among elderly men, they are usually considered synonymous with benign prostatic hyperplasia (BPH). Drugs should be the first-line treatment for BPH and surgical intervention should be performed only when there are complications or LUTS refractory to medical treatment. In addition to medical treatment, several minimally invasive therapies, such as thermal therapy, prostatic lift, laser evaporation, or laser enucleation techniques have been developed. Recent investigations have also revealed that bladder dysfunction such as detrusor overactivity and detrusor underactivity may also contribute to male LUTS. In the treatment of LUTS suggestive of BPH (LUTS/BPH), the following questions should be considered: Is there an obstruction? Are we treating BPH or LUTS? Can management targeting BPH reduce LUTS? Should patients with LUTS be treated before bladder outlet obstruction is confirmed? What is the role of transurethral resection of the prostate (TURP) nowadays? Will new techniques provide better outcomes than TURP? This article discusses the current consensus and controversies in the treatment of LUTS/BPH.

Intravesical OnabotulinumtoxinA Injection for Overactive Bladder Patients with Frailty, Medical Comorbidities or Prior Lower Urinary Tract Surgery

Overactive bladder (OAB) symptoms increase with age and involve several comorbidities. OnabotulinumtoxinA (BoNT-A) intravesical injection is a treatment choice for patients who are intolerant of or refractory to antimuscarinics. However, the increased risk of urinary tract infection and elevated post-void residual (PVR) volume post-treatment require resolution. Male sex, baseline PVR > 100 mL, and comorbidities are independent risk factors of adverse events (AEs) such as acute urinary retention (AUR). Intravesical BoNT-A injection is safe and effective for OAB patients with frailty, medical comorbidities such as Parkinson's disease (PD), chronic cerebrovascular accidents (CVA), dementia, or diabetes, or a history of prior lower urinary tract surgery (prostate or transvaginal sling surgery). Post-treatment, 60% of frail elderly patients had a PVR volume > 150 mL and 11% had AUR. Although intravesical BoNT-A injection is safe for PD patients, CVA patients had higher strain voiding rates. Diabetic patients were at increased risk of large PVR urine volume and general weakness post-treatment. Treatment results were similar between patients with and without a history of prostate or transvaginal sling surgery. Possible AEs and bladder management strategies should be conveyed to patients before treatment. Careful patient selection is important, and therapeutic safety and efficacy should be carefully balanced.

Detrusor sphincter dyssynergia: a review of physiology, diagnosis, and treatment strategies

Detrusor sphincter dyssynergia (DSD) is the urodynamic description of bladder outlet obstruction from detrusor muscle contraction with concomitant involuntary urethral sphincter activation. DSD is associated with neurologic conditions such as spinal cord injury, multiple sclerosis, and spina bifida and some of these neurogenic bladder patients with DSD may be at risk for autonomic dysreflexia, recurrent urinary tract infections, or upper tract compromise if the condition is not followed and treated appropriately. It is diagnosed most commonly during the voiding phase of urodynamic studies using EMG recordings and voiding cystourethrograms, although urethral pressure monitoring could also potentially be used. DSD can be sub-classified as either continuous or intermittent, although adoption of this terminology is not widespread. There are few validated oral pharmacologic treatment options for this condition but transurethral botulinum toxin injection have shown temporary efficacy in reducing bladder outlet obstruction. Urinary sphincterotomy has also demonstrated reproducible long term benefits in several studies, but the morbidity associated with this procedure can be high.

OnabotulinumtoxinA Treatment for Overactive Bladder in the Elderly: Practical Points and Future Prospects

Overactive bladder (OAB) increases with age. OAB in the elderly may be associated with increased risks of falls, fractures and mortality. Degeneration of the central nervous system in the elderly is proposed as one of the pathogenic factors for OAB. Recently, onabotulinumtoxinA (BoNT-A) 100 U has been demonstrated to be well tolerated, and it significantly improves all OAB symptoms and health-related quality of life in patients who are inadequately managed with anticholinergics. However, an increased risk of a large post-void residual volume and a lower long-term success rate were noted in frail elderly patients. Careful patient selection for BoNT-A injection treatment is important in elderly OAB patients. Patients who are frail, are elderly, have comorbidity or have a post-void residual volume >100 mL should be monitored carefully after BoNT-A injection treatment to prevent urinary retention and subsequent urinary tract infection. Use of liposomes to carry BoNT-A across the urothelial barrier decreases urgency-frequency episodes without compromising detrusor contractility and might avoid urinary tract infection. This treatment might prevent undesired detrusor underactivity after BoNT-A injection treatment, especially in elderly patients who have low detrusor contractility. For treatment of OAB in the elderly, clinicians should be aware of the balance between therapeutic efficacy and safety.

Outcomes of drug-resistant urinary retention in patients in the early stage of stroke

OBJECTIVE

To investigate the prognosis of patients with stroke and urinary retention resistant to alpha blockers and cholinergic agents.

METHODS

Post-void residual urine volume (PVR) was measured in 33 patients with stroke (14 men and 19 women) who were admitted to the department of rehabilitation medicine of our hospital within 30 days after stroke onset. An alpha-blocker and cholinergic agent were administered to patients with PVR >100 mL. If urinary retention had not improved despite the maximum drug doses, the patient was diagnosed with drug-resistant urinary retention. We retrospectively reviewed patient's charts, including PVR at discharge and prognostic factors for PVR.

RESULTS

Ten patients (30.3%) could not void or their PVR was >400 mL at discharge (45.7±15.4 days after onset) after rehabilitation. Twelve patients (36.4%) could void, and their PVR was 100-400 mL. PVR was consistently <100 mL in 11 patients (33.3%). These measurements correlated with the Korean version of the Modified Barthel Index score, Functional Ambulation Category, and the presence of a communication disorder.

CONCLUSION

The results show that 22 patients (66.7%) had incomplete bladder emptying or required catheterization at discharge. Outcomes correlated with functional status, walking ability, and the presence of a communication disorder. Patients with urinary retention and poor general condition require close observation to prevent complications of urinary retention.

In vivo roles for myosin phosphatase targeting subunit-1 phosphorylation sites T694 and T852 in bladder smooth muscle contraction

KEY POINTS

Force production and maintenance in smooth muscle is largely controlled by myosin regulatory light chain (RLC) phosphorylation, which relies on a balance between Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) activities. MYPT1 is the regulatory subunit of MLCP that biochemically inhibits MLCP activity via T694 or T852 phosphorylation in vitro. Here we separately investigated the contribution of these two phosphorylation sites in bladder smooth muscles by establishing two single point mutation mouse lines, T694A and T852A, and found that phosphorylation of MYPT1 T694, but not T852, mediates force maintenance via inhibition of MLCP activity and enhancement of RLC phosphorylation in vivo. Our findings reveal the role of MYPT1 T694/T852 phosphorylation in vivo in regulation of smooth muscle contraction.

ABSTRACT

Force production and maintenance in smooth muscle is largely controlled by different signalling modules that fine tune myosin regulatory light chain (RLC) phosphorylation, which relies on a balance between Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) activities. To investigate the regulation of MLCP activity in vivo, we analysed the role of two phosphorylation sites on MYPT1 (regulatory subunit of MLCP) that biochemically inhibit MLCP activity in vitro. MYPT1 is constitutively phosphorylated at T694 by unidentified kinases in vivo, whereas the T852 site is phosphorylated by RhoA-associated protein kinase (ROCK). We established two mouse lines with alanine substitution of T694 or T852. Isolated bladder smooth muscle from T852A mice displayed no significant changes in RLC phosphorylation or force responses, but force was inhibited with a ROCK inhibitor. In contrast, smooth muscles containing the T694A mutation showed a significant reduction of force along with reduced RLC phosphorylation. The contractile responses of T694A mutant smooth muscle were also independent of ROCK activation. Thus, phosphorylation of MYPT1 T694, but not T852, is a primary mechanism contributing to inhibition of MLCP activity and enhancement of RLC phosphorylation in vivo. The constitutive phosphorylation of MYPT1 T694 may provide a mechanism for regulating force maintenance of smooth muscle.

Efficacy and safety of intravesical onabotulinumtoxinA injection on elderly patients with chronic central nervous system lesions and overactive bladder

PURPOSE

Intravesical injection of onabotulinumtoxinA is an effective treatment for overactive bladder (OAB). Nonetheless, the treatment outcome is unclear in OAB patients with central nervous system (CNS) lesions. This study evaluated the efficacy and safety of intravesical onabotulinumtoxinA treatment in elderly patients with chronic cerebrovascular accidents (CVAs), Parkinson's disease (PD) and dementia.

MATERIALS AND METHODS

Patients with CVA, PD, dementia, and OAB refractory to antimuscarinic therapy were consecutively enrolled in the study group. Age-matched OAB patients without CNS lesions were selected to serve as a control group. OnabotulinumtoxinA (100 U) was injected into the bladder suburothelium at 20 sites. The clinical effects, adverse events, and urodynamic parameters were assessed at baseline and 3 months post-treatment. The Kaplan-Meier method was used to compare long-term success rates between groups.

RESULTS

A total of 40 patients with OAB due to CVA (23), PD (9), dementia (8) and 160 control patients were included in this retrospetive analysis. Improvement of urgency severity scale, increased bladder capacity and increased post-void residual volume were comparable between the groups at 3 months. Patients with CNS lesions did not experience increased risks of acute urinary retention and urinary tract infection; nonetheless, patients with CVA experienced a higher rate of straining to void. Long-term success rates did not differ between the patients with and without CNS lesions.

CONCLUSION

Intravesical injection of 100 U of onabotulinumtoxinA effectively decreased urgency symptoms in elderly OAB patients with CNS lesions. The adverse events were acceptable, and long-term effects were comparable to OAB patients in general. Nonetheless, the possibility of longstanding urinary retention and chronic catheterization need careful evaluation for this very vulnerable population before choosing intravesical onabotulinumtoxinA treatment.

Effects of electroacupuncture on recent stroke inpatients with incomplete bladder emptying: a preliminary study

Background

Incomplete bladder emptying (IBE) is defined as having a postvoid residual (PVR) urine volume greater than 100 mL for 2 consecutive days. IBE is common in stroke patients and could necessitate indwelling or intermittent catheterization. The condition is correlated with urinary tract infections, which could impede rehabilitation progress and increase medical costs. Treatment for patients with IBE includes bladder retraining, biofeedback, medication, and botulinum toxin injection, but none of these interventions are completely effective.

Methods

All patients with acute stroke who were admitted to the rehabilitation ward between August 2010 and April 2011 were included in the study and their PVR urine volume was checked. Electroacupuncture (EA; 1 Hz, 15 minutes) was performed on the acupoints Sanyinjiao (SP6), Ciliao (BL32), and Pangguangshu (BL28) of stroke patients with IBE for a total of ten treatments (five times a week for 2 weeks). Bladder diaries, which included the spontaneous voiding and PVR urine volumes, were recorded during the course of treatment.

Results

The presence of IBE was not related to sex, history of diabetes mellitus, stroke type (hemorrhagic or ischemic), or stroke location (P > 0.05). Among the 49 patients in the study, nine (18%) had IBE, and seven of the stroke patients with IBE were treated with EA. Increased spontaneous voiding volume and decreased PVR urine volume were noted after ten sessions of EA.

Conclusion

EA may have beneficial effects on stroke survivors with IBE, thereby making it a potential safe modality with which to improve urinary function.

Indwelling urinary catheterization after acute stroke

AIMS

Prolonged indwelling urinary catheterization (IUC) increases risk of urinary tract infection. We aimed to investigate the incidence and risk factors associated with IUC following acute stroke, and its impact on stroke outcome.

METHODS

We prospectively enrolled stroke patients hospitalized within 10 days after onset from August 2006 to December 2008. Kaplan-Meier method was used to estimate the cumulative incidence of IUC, and Cox regression analysis to evaluate the independent predictors. The impact of IUC on poor outcome (modified Rankin Scale >2 or dead) at 3 months was studied by logistic regression.

RESULTS

Of 2,803 patients, 697 (25%) received indwelling urinary catheters. Catheterization was carried out mostly within 1-2 days of admission (86%), with estimated cumulative incidence of 13% (95% confidence interval, 11-14%) at 2 days in patients with ischemic stroke (IS), and 57% (53-61%) in patients with intracerebral hemorrhage (ICH). In IS patients, IUC was significantly associated with increasing age, baseline stroke severity, and neurological deterioration. In ICH patients, stroke severity on admission was the only significant predictor after adjustment. We assessed the 3-month outcome in 2,388 patients, after excluding 177 (6%) dead at discharge, 164 (6%) without providing informed consent, and 74 (3%) lost to follow-up. IUC during acute hospitalization was significantly associated with unfavorable 3-month outcome after adjustment.

CONCLUSIONS

IUC was common in acute stroke care and associated with unfavorable outcome at 3 months. Whether judicious use of urinary catheters in acute stroke patients would improve outcomes may warrant further studies.

Detrusor underactivity: a plea for new approaches to a common bladder dysfunction

AIMS

Detrusor underactivity (DU) is defined by the International Continence Society as a contraction of reduced strength and/or duration resulting in prolonged or incomplete emptying of the bladder but has yet received only little attention. The purpose of this report is to summarize the ICI-RS meeting in Bristol in 2010 exploring current knowledge on DU and outline directions for future research.

METHODS

A think tank discussion was held and the summary of discussions was presented to all ICI-RS participants. This report is based on the final discussions.

RESULTS

The understanding of the pathophysiology, epidemiology, assessment, and treatment of DU remains rudimentary. DU is defined by pressure-flow analysis but no consensus exists regarding which of the available formulae should be used for quantification of detrusor work. DU is likely to be multifactorial. Aging causes a decay in detrusor activity but other concomitant causes, either myogenic or neurogenic, may aggravate the problem resulting in decrease of detrusor contractility. No effective pharmacotherapy for the condition exists. Only a few surgical therapeutic strategies have been explored, such as neuromodulation and skeletal muscle myoplasties. Consequently, the management of affected individuals remains unsatisfactory.

CONCLUSIONS

Future directions recommended by the ICI-RS panel include assessment of pathogenesis by developing novel animal models in addition to new non-invasive tests allowing longitudinal trials. Furthermore, optimizing the existing evaluation algorithms to support standard testing for DU and further epidemiological studies to quantify the size of the problem are required for the development of future treatment modalities.