Structural Basis of Geriatric Voiding Dysfunction. VII. Prospective Ultrastructural/Urodynamic Evaluation of Its Natural Evolution

Managing Nocturia in Frail Older Adults

This review discusses the available evidence in the current evaluation and treatment of nocturia in frail older adults. No evidence specifically evaluates the use of behavioral interventions in the treatment of the frail older adult with nocturia, but their use is supported in other cohorts. Behavioral modifications and optimal management of comorbidities remain the first-line treatment for all age groups and should be emphasized in the frail due to their favorable safety profile. No studies specific to the frail older adult support the use of pharmacotherapy. Some evidence exists for the efficacy of several agents in the older adult; however, this is difficult to extrapolate to the frail, and safety concerns abound. Desmopressin may be effective in the older adult, but a high risk of hyponatremia raises concerns for its safety, and therefore it is not recommended in the frail. α-Antagonists may have limited efficacy in men with known benign prostatic hyperplasia (BPH); they are relatively well tolerated, although the risk of orthostatic hypotension in the frail should be considered. β3-agonist trials suggest limited clinical utility. Antimuscarinics are not found to be useful in this cohort and are contraindicated in the frail older adult given the ability of antimuscarinics to cause cognitive impairment, delirium, and falls. No data examine the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in the frail older adult. Additionally, the American Geriatrics Society Beers Criteria recommends against the use of muscarinics in those over the age of 75 years and therefore their use is not supported.

Dilemmas in Management of the Geriatric Bladder

Purpose of review

In this article, we will review current dilemmas regarding evaluation and management of the geriatric bladder incorporating concepts of normal changes of aging as well as common lower urinary tract dysfunction.

Recent findings

Increasing age leads to functional changes in essentially all organ systems including the genitourinary system. Understanding the natural changes with age of the bladder as well as the signs and symptoms of pathologic conditions is paramount to diagnosis and treatment of urologic conditions in the geriatric population.

Summary

There are several conundrums in the diagnosis and evaluation of the geriatric bladder including the ability of the bladder to store, empty, as well as sensitivity disturbances. Diagnostic testing and goals of treatment should be individualized for each patient and personalized to consider patient comorbidities, limitations, and expectations.

Current concepts of the acontractile bladder

The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments.

Do urodynamics provide a better understanding of voiding disorders in women over 80?

AIMS

Population ageing has as consequence an increasing number of women older than 80 years with lower urinary tract symptoms (LUTS). Despite old age, urodynamic study is often performed to diagnose the cause of LUTS. Our purpose is to discuss the contribution of urodynamics to manage that population.

METHODS

Urodynamic studies of 169 consecutive women older than 80 years, respectively 124 non-neurological (non-N) and 45 neurological (N), were retrospectively analysed.

RESULTS

Number of co-morbidities was lower in non-N (2.5 vs. 3.1) with predominance of cardiovascular and endocrinology while musculo-skeletal, cognitive and previous pelvic surgery predominated in N. Among main complaint, incomplete retention or dysuria was more frequent in N while incontinence and frequency were predominant in non-N. More frequent urodynamic diagnosis (UD) was "normal" i.e. non contributive (25.0%) and intrinsic sphincter deficiency (ISD=21.7%) in non-N, detrusor overactivity (DO=42.2%) and detrusor underactivity (DU=38.8%) in N. In non-N, there were 94 treatment proposals based on the complaint when UD was "normal" and on UD for DO, DU and ISD. In N, treatment proposals were mainly prompted voiding or self-catheterization based on DU diagnosis.

CONCLUSION

Usefulness of urodynamics to manage LUT dysfunction in women older than 80 y is greatly dependent on their neurological status. In non-neurological women this is non debatable but proposed treatment needs to take into account existing co-morbidities. In neurological women the main usefulness is to unmask DU and to propose the best management in order to avoid complete retention.

LEVEL OF EVIDENCE

4.

Pathophysiology of the underactive bladder

Underactive bladder (UAB), which has been described as a symptom complex suggestive of detrusor underactivity, is usually characterized by prolonged urination time with or without a sensation of incomplete bladder emptying, usually with hesitancy, reduced sensation on filling, and slow stream often with storage symptoms. Several causes such as aging, bladder outlet obstruction, diabetes mellitus, neurologic disorders, and nervous injury to the spinal cord, cauda equine, and peripheral pelvic nerve have been assumed to be responsible for the development of UAB. Several contributing factors have been suggested in the pathophysiology of UAB, including myogenic failure, efferent and/or afferent dysfunctions, and central nervous system dysfunction. In this review article, we have described relationships between individual contributing factors and the pathophysiology of UAB based on previous reports. However, many pathophysiological uncertainties still remain, which require more investigations using appropriate animal models.

Underactive bladder: Pathophysiology and clinical significance

Underactive bladder (UAB) is a voiding disorder which generates disabling lower urinary tract symptoms (LUTS) due to the inability to produce an effective voiding contraction sufficient to empty the bladder. The underlying abnormality, that is usually appreciated when performing urodynamic studies, has been defined by the International Continence Society (ICS) as detrusor underactivity (DUA). DUA is a common yet under-researched bladder dysfunction. The prevalence of DUA in different patient groups suggests that multiple aetiologies are implicated. Currently there is no effective therapeutic approach to treat this condition. An improved understanding of the underlying mechanisms is needed to facilitate the development of new advances in treatment. The purpose of this review is to discuss the epidemiology, pathophysiology, common causes and risk factors potentially leading to DUA; to aid in the appropriate diagnosis of DUA to potentially improve treatment outcomes.

Lower urinary tract dysfunction in patients with brain lesions

Stroke and brain tumor are well-known brain diseases. The incidence of lower urinary tract dysfunction (LUTD) in these patients ranges from 14% to 53%, mostly overactive bladder (OAB), and is higher when the frontal cortex is involved. This presumably reflects damage at the prefrontal cortex, cingulate cortex, and other areas that regulate (mainly inhibit) the micturition reflex. White-matter disease (WMD) is a chronic, bilateral form of cerebrovascular disease, leading to a high prevalence of OAB (up to 90%). Since WMD is particularly common in the elderly, WMD may be one of the anatomic substrates for elderly OAB. Traumatic brain injury and normal-pressure hydrocephalus are rather diffuse brain diseases, which cause OAB with a prevalence rate of 60-95%. Recent neuroimaging studies have shown a relationship between LUTD and the frontal cortex in these diseases. Data on other brain diseases, particularly affecting deep brain structures, are limited. Small infarctions, tumors, or inflammatory diseases affecting the basal ganglia, hypothalamus, and cerebellum lead to mainly OAB. In contrast, similar diseases affecting the brainstem lead to either OAB or urinary retention. The latter reflects damage at the periaqueductal gray and the pontine micturition center that directly relay and modulate the micturition reflex. Urinary incontinence (UI) in brain disease can be divided into two types: neurogenic UI (due to OAB) and functional UI (immobility and loss of initiative/cognition). These two types of UI may occur together, but management differs significantly. Management of neurogenic UI includes anticholinergic drugs that do not penetrate the blood-brain barrier easily. Management of functional UI includes behavioral therapy (timed/prompted voiding with physical assistance and bladder/pelvic floor training) and drugs to treat gait as well as cognition that facilitate continence. These treatments will maximize the quality of life in patients with brain diseases.

Is overactive bladder a brain disease? The pathophysiological role of cerebral white matter in the elderly

Small-vessel disease of the brain affecting the deep white matter characteristically manifests with neurological syndromes, such as vascular dementia and vascular parkinsonism. There is, however, compelling evidence to suggest that white matter disease can cause overactive bladder and incontinence, and in some patients these might be the initial manifestation. As white matter disease increases significantly with age, and preferentially affects the prefrontal deep white matter, white matter disease becomes an anatomical substrate in the brain etiology of overactive bladder. Treatment entails the management of small-vessel disease risk factors and anticholinergic drugs that do not easily penetrate the blood-brain barrier, to improve bladder control. In short, when caring for elderly overactive-bladder patients, we should look at both the brain and the bladder.

Pathophysiology of overactive bladder

Overactive bladder (OAB) is a common disorder that negatively affects the quality of life of our patients and carries a large socioeconomic burden. According to the International Continence Society, it is characterized as urinary urgency, with or without urge incontinence, usually, with frequency and nocturia in the absence of causative infection. The pathophysiology of this disease entity varies between neurogenic, myogenic, or idiopathic factors. This paper provides a review of the contemporary theories behind the pathophysiology of OAB.

Overactive bladder in males

The prevalence of overactive bladder (OAB) symptoms is considerable in both men and women and the impact on quality of life (QOL) is equally substantial. Ironically, despite nearly equal prevalence, OAB symptoms in men are infrequently treated, and often with medical therapies aimed at bladder outlet obstruction (BOO). In this review, we examine the pathophysiology of OAB and its evaluation in the context of benign prostatic hypertrophy and concomitant BOO. We then consider the efficacy and safety of individual therapeutic options for lower urinary tract symptoms in men, focusing on the mainstays of medical therapy: α-adrenergic blockers, 5-α reductase inhibitors, and antimuscarinic agents. Finally, we aim to comment on new therapeutic strategies and targets that may one day be available for the treatment of male OAB.

Parameters of bladder function in pre-, peri-, and postmenopausal continent women without detrusor overactivity

AIMS

To determine normative data for lower urinary tract function in asymptomatic continent women without detrusor overactivity (DO) across the age span.

METHODS

Healthy female volunteers aged > or =20 years were recruited from the community. Comprehensive assessment included bladder diary, physical examination, uroflowmetry, and video-urodynamics. Continent women without history of frequent urgency and without DO were selected. Data on bladder storage, voiding and urethral sphincter function, urine output and frequency are presented for pre-, peri-, and postmenopausal women.

RESULTS

Twenty-four asymptomatic women (mean age 50.2 years, range 22-80 years) met the inclusion criteria, including 7 pre- (29.2 years), 7 peri- (48.8 years), and 10 postmenopausal (66.0 years) women. For all subjects, maximum single voided volume in bladder diary was 500 ml and maximum cystometric capacity was 580 ml (median values). Strong desire to void (SDV) was reported at 287, 366, and 425 ml for pre-, peri-, and postmenopausal groups, respectively. The maximum flow rate was 25, 32, and 23 ml/sec in uroflowmetry and 23, 24, and 18 ml/sec in pressure-flow study, respectively. Median post-void residual volume (PVR) was below 20 ml in all groups. At maximum flow rate subjects voided with detrusor pressures of 29, 26, and 24 cm H(2)O, respectively. Maximum urethral closure pressure was 94, 74, and 42 cm H(2)O, respectively.

CONCLUSIONS

We provide normative data on bladder function in asymptomatic, continent, pre-, peri-, and postmenopausal women without DO.

Null mutation in macrophage migration inhibitory factor prevents muscle cell loss and fibrosis in partial bladder outlet obstruction

Idiopathic detrusor underactivity (DU) and detrusor decompensation which develops following partial bladder outlet obstruction (pBOO) are both associated with smooth muscle degeneration and fibrosis. Macrophage migration inhibitory factor (MIF), an important mediator of bladder inflammation, has been shown to promote fibroblast survival and muscle death in other tissues. We evaluated the hypothesis that MIF has similar actions in the bladder by studying detrusor responses to pBOO or sham surgery in anesthetized female mice rendered null for the mif gene (MIF KO) and in wild-type (WT) controls, all killed 3 wk after surgery. WT mice revealed intense MIF immunoreactivity in urothelial cells which decreased, without change in overall mif mRNA levels. Stereologically sound quantitative morphometric measurements were performed in the middetrusor region of each bladder. MIF KO bladders were normal in appearance, yet were 30–40% heavier, with increased middetrusor collagen and muscle, compared with WT controls. In WT mice, pBOO increased the collagen-to-muscle ratio 1.9-fold and middetrusor collagen 1.8-fold, while nucleated muscle counts were 22% lower. In MIF KO mice, by contrast, pBOO had no significant effect on any of these parameters. In primary bladder muscle cultures, treatment with rMIF protein increased TUNEL staining, raising the proportion of early and late apoptotic cells on flow cytometry. Our studies implicate MIF in the sequence of events leading to detrusor muscle loss and fibrosis in obstruction. They raise the possibility that strategies designed to antagonize MIF synthesis, release, or biological activity could prevent or delay DU and urinary retention.

Do atherosclerosis and chronic bladder ischemia really play a role in detrusor dysfunction of old age?

OBJECTIVES

To determine whether atherosclerosis-induced chronic pelvic ischemia plays a role in the pathogenesis of aging bladder dysfunction.

METHODS

Old (70 weeks of age), apolipoprotein E gene knockout (APOEKO) mice, known to develop atherosclerosis spontaneously were used. A group of 70-week-old C57B mice were used as controls. The mice were killed and bladder smooth muscle strips obtained for in vitro contractile force determinations. The maximal contractions in response to 110 mM KCl, 10(-5) M bethanechol, and resting muscle tone were compared. The abdominal aortas and iliac arteries were harvested from the mice, and computerized image analysis was used to determine the percentage of surface area of atherosclerosis in each mouse.

RESULTS

Although the APOEKO mice had massive atherosclerosis of the abdominal aortas and iliac arteries (lesion surface area +/- SEM 15.93% +/- 3.02%, n = 4), the control mice (n = 5) had no atherosclerosis at all. No statistically significant difference was found in detrusor function (KCl 0.48 +/- 0.11 versus 0.49 +/- 0.05, bethanechol 0.11 +/- 0.02 versus 0.13 +/- 0.04, tone 0.063 +/- 0.019 versus 0.07 +/- 0.004, respectively) between the APOEKO mice (n = 6) and the control mice (n = 6).

CONCLUSIONS

Pelvic atherosclerosis caused no statistically significant changes in bladder smooth muscle contractile responses to bethanechol, KCl, or resting tone. The difference between these and previously reported results may have been a result of the more gradual onset of atherosclerosis in our model, which better mimics pelvic organ ischemia in the elderly.

Lower urinary tract symptoms in men and women without underlying disease causing micturition disorder: a cross-sectional study assessing the natural history of bladder function

PURPOSE

We examined the influence of aging on bladder function in men and women.

MATERIALS AND METHODS

Using the International Prostate Symptom Score questionnaire with an additional question on urinary incontinence lower urinary tract symptoms were evaluated in all outpatients who first visited our urological department from June 2001 to December 2002. In 550 of the 1,201 patients who completed the questionnaire any pathological conditions that might cause micturition disorder could not be detected with urological examinations. Symptom scores of these patients without underlying disease causing micturition disorder were the basis of this study.

RESULTS

In men and women total and storage symptom scores but not the voiding symptom score increased significantly with age. In each age group total, storage and voiding symp-tom scores were not significantly different between men and women. Women 50 to 69 years old had significant higher incontinence scores than men of the same age, whereas a significant increase in the incontinence score with age was found only in men. The quality of life score increased with age in men but not in women. However, the 2 sexes did not significantly differ in quality of life score.

CONCLUSIONS

Lower urinary tract symptoms, especially storage symptoms, showed age related alterations in the 2 sexes without any underlying disease causing micturition disorder. The prevalence of urinary symptoms was not different between men and women. Therefore, bladder function in each sex might be subject to a gender independent aging process.

A prospective evaluation of detrusor ultrastructural changes in bladder outlet obstruction

OBJECTIVES

To characterize the ultrastructure of detrusor smooth muscle from the bladders of symptomatic men with bladder outlet obstruction (BOO) caused by benign prostatic enlargement (BPE) and compare this with a matched control group; to determine how detrusor morphology relates to urodynamic findings and to develop a better understanding of the natural development of bladder dysfunction related to BOO.

PATIENTS AND METHODS

Twelve men (mean age 66 years, range 52-77) with urodynamically confirmed BOO caused by BPE and 12 age-matched asymptomatic normally voiding controls (mean age 67.8 years, undergoing cystoscopy for other conditions) had detrusor biopsies taken endoscopically. The biopsies were processed for electron microscopy using standard methods. The specimens were randomized and examined at medium power (x 4000) by an examiner unaware of the urodynamic findings. Any ultrastructural patterns identified subjectively were noted.

RESULTS

In the BOO group eight of the 12 men had a myohypertrophic pattern, half of which were associated with a degenerative pattern of hypocontractility. Of the remaining four patients, two had the degenerative pattern alone and two were normal. The six men whose biopsies had a degenerative pattern had consistent postvoid residual volumes of > 150 mL; the remainder all had volumes of < 150 mL. There were no ultrastructural abnormalities in the control patients.

CONCLUSIONS

There are interesting qualitative ultrastructural changes in the obstructed detrusor, but they are not consistent enough to provide a reliable diagnostic tool. However, there may be an important relationship between the degenerative pattern and postvoid residual volume in BOO.

Pathophysiology: the varieties of bladder overactivity

Overactive bladder (OAB) is the most common term currently used in clinical medicine to describe a complex of lower urinary tract symptoms (LUTS) with or without incontinence. The symptoms usually include urgency, frequency, nocturia, troublesome or incomplete emptying, and, occasionally, pain. Causes of bladder overactivity include neurologic illness or injury, bladder outlet obstruction, urethral weakness, detrusor hyperactivity and impaired contractility in elderly patients, emergence of new voiding reflexes, and so-called idiopathic bladder overactivity. Most clinicians agree that effective treatment for OAB symptoms should be guided by a basic assessment of patients for these contributing factors. However, it is not at all certain that outcomes are significantly improved by diagnostic precision. This is in part because of the ubiquity of LUTS in the setting of the various common lower urinary tract disorders: stress incontinence, outlet obstruction, and neurologic illness or injury. The ubiquity of LUTS would imply that they are caused by common mechanisms and, theoretically at least, would be amenable to a single form of effective therapy. Conversely, the limited kinds and number of LUTS and the limited representation of lower urinary tract structures in the central nervous system may mean that several different causes produce similar symptoms, but these are not amenable to a single form of effective therapy. Future research directions should keep each possible explanation in mind as new knowledge about lower urinary tract function and possible intervention continues to emerge.

Geriatric considerations in the diagnosis and management of overactive bladder

Numerous considerations affect the diagnosis and management of overactive bladder (OAB) in older patients, including neurologic and cardiovascular disorders, musculoskeletal conditions, diabetes, and psychiatric disorders. Older patients are commonly prescribed multiple medications, and many medications can contribute to OAB symptoms and/or interact with drug treatment for OAB. In addition to chronic illnesses and related medications, several factors outside the lower urinary tract can play an important part in managing OAB in older patients. These factors include mobility disorders, cognitive impairment, bowel habits, and fluid intake. Moreover, OAB often does not occur in isolation in the geriatric population. Estrogen deficiency and sphincter weakness in women, prostatic enlargement and obstruction in men, and impaired bladder contractility in both sexes are common and can have prominent effects on management. The diagnostic evaluation of geriatric patients with OAB can usually be accomplished with a basic assessment, without more invasive and expensive procedures. Treatment depends on numerous factors, ranging from comorbidities and functional status to transportation, finances, and patient and caregiver preferences. Adverse effects of bladder-relaxant medications can be bothersome and exacerbate existing conditions common in older patients (eg, constipation, glaucoma, gastroesophageal reflux, and dementia). Setting realistic goals for treatment and communicating them clearly to older patients and their caregivers are crucial for patient satisfaction. There are myriad opportunities for research designed to improve the management of OAB in the geriatric population.

Diagnosis and significance of idiopathic overactive bladder

OBJECTIVES

To offer a critical overview of the basis for the International Continence Society (ICS) classification of detrusor instability, to summarize current diagnostic methodologies, and to outline the etiologic factors that should be excluded in the diagnosis of idiopathic overactive bladder.

METHODS

The current ICS definitions of overactive bladder are discussed. Issues related to the diagnosis of detrusor instability (DI) are addressed through a review of the literature.

RESULTS

The term idiopathic overactive bladder reflects the present lack of knowledge concerning vesicourethral function and dysfunction. The term is used to apply to a wide spectrum of different conditions that may have a common final pathophysiologic pathway. This heterogeneous group of conditions could be subdivided on the basis of presumptive etiopathogenesis, urodynamic patterns, and response to treatment. The diagnosis of DI, its rate of detection, and its urodynamic patterns depend on the type of urodynamic test used and the way the test is performed. The ICS definitions of DI have been called into question by the results of studies using urodynamic tests in addition to, or instead of, provocative cystometry--for instance, ambulatory urodynamics, urethrocystometry, the ice-water test, and evaluation of the voiding phase. The literature supports a broadening of the ICS criteria for excluding all known causes of DI when establishing the diagnosis of idiopathic overactive bladder.

CONCLUSIONS

Appropriate longitudinal studies, using contemporary urodynamic tests and knowledge, are needed to improve the identification of subsets of patients with overactive bladder who have different prognoses and outcomes. The ICS definitions and classification should be updated.

A myogenic basis for the overactive bladder

OBJECTIVES

This article summarizes evidence supporting the conclusion that the spontaneous rises in pressure that occur in the overactive bladder, particularly in detrusor instability (DI), regardless of etiology, are myogenic.

METHODS

The evidence quoted has been obtained by several groups of investigators and includes electrophysiologic studies of detrusor myocytes, tension studies of strips of smooth muscle, in vivo experiments on animal models, and light and electron microscopic studies of the structure of the bladder wall.

RESULTS

The results of these studies demonstrate changes in the properties, structure, and innervation of the detrusor. These changes are consistent with the hypothesis that partial denervation of the detrusor may be responsible for altering the properties of the smooth muscle, leading to increased excitability and increased ability of activity to spread between cells, resulting in coordinated myogenic contractions of the whole detrusor.

CONCLUSIONS

It is suggested that alterations in the properties of the detrusor myocytes are a necessary prerequisite for the production of the unstable pressure rises seen in DI of any origin.