White Matter Lesions or Alzheimer's Disease: Which Contributes More to Overactive Bladder and Incontinence in Elderly Adults with Dementia?

Urinary dysfunction in patients with vascular cognitive impairment

Vascular cognitive impairment (VCI) is caused by vascular pathologies, with the spectrum of cognitive disorders ranging from subjective cognitive dysfunction to dementia. Particularly among older adults, cognitive impairment is often complicated with urinary dysfunction (UD); some patients may present with UD before cognitive impairment owing to stroke or even when there are white matter hyperintensities on imaging studies. Patients with cognitive impairment often have both language and movement dysfunction, and thus, UD in patients with VCI can often be underdiagnosed and remain untreated. UD has an impact on the quality of life of patients and caregivers, often leading to poor outcomes. Medical history is an important aspect and should be taken from both patients and their caregivers. Clinical assessment including urinalysis, voiding diary, scales on UD and cognitive impairment, post-void residual volume measurement, uroflowmetry, and (video-) urodynamics should be performed according to indication. Although studies on UD with VCI are few, most of them show that an overactive bladder (OAB) is the most common UD type, and urinary incontinence is the most common symptom. Normal urine storage and micturition in a specific environment are complex processes that require a sophisticated neural network. Although there are many studies on the brain-urinary circuit, the specific circuit involving VCI and UD remains unclear. Currently, there is no disease-modifying pharmacological treatment for cognitive impairment, and anti-acetylcholine drugs, which are commonly used to treat OAB, may cause cognitive impairment, leading to a vicious circle. Therefore, it is important to understand the complex interaction between UD and VCI and formulate individualized treatment plans. This review provides an overview of research advances in clinical features, imaging and pathological characteristics, and treatment options of UD in patients with VCI to increase subject awareness, facilitate research, and improve diagnosis and treatment rates.

Alzheimer's disease amyloidogenesis is linked to altered lower urinary tract physiology

AIMS

While most Alzheimer's disease (AD) research emphasizes cognitive and behavioral abnormalities, lower urinary tract symptoms (LUTS) are observed in a third of AD patients, contributing to morbidity, poor quality of life, and need for institutionalization. Alzheimer's disease-associated urinary dysfunction (ADUD) has been assumed to be due to cognitive decline alone. While mouse studies have suggested that bladder innervation and voiding behavior may be altered in AD models, technical challenges precluded voiding reflex assessments. This study seeks to establish a mouse model of ADUD, and it seeks to characterize the noncognitive sequelae involved in AD-pathology associated alterations in the voiding reflex.

METHODS

Having developed techniques permitting the assessment of bladder volume, pressure, and flow in mice, we now provide evidence of alterations in involuntary bladder control and increased response heterogeneity in a transgenic amyloidosis mouse model of AD using cystometry and tissue pharmacomyography. Tg-APP/PS1DE9 (PA) mice and their wild-type (WT) littermates (n = 6-8 per group) were used before plaque onset in the PA mice (4-6 months) and after plaque accumulation in the PA mice (8-10 months) in comparison to their WT control littermates.

RESULTS

Novel findings include data suggestive of sphincteric discoordination, with pharmacological evidence of altered adrenergic mechanisms.

CONCLUSIONS

Together, these data highlight the importance of addressing noncognitive sequelae of AD and offer novel translational insights into the debilitating impact of AD on LUTS and incontinence.

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer’s disease, and Parkinson’s disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

Overactive Bladder Symptoms Within Nervous System: A Focus on Etiology

Overactive bladder (OAB) is a common debilitating condition characterized by urgency symptoms with detrimental effects on the quality of life and survival. The exact etiology of OAB is still enigmatic, and none of therapeutic approaches seems curative. OAB is generally regarded as a separate syndrome, whereas in clinic, OAB symptoms could be found in numerous diseases of other non-urogenital systems, particularly nervous system. The OAB symptoms in neurological diseases are often poorly recognized and inadequately treated. This review provided a comprehensive overview of recent findings related to the neurogenic OAB symptoms. Relevant neurological diseases could be mainly divided into seven kinds as follows: multiple sclerosis and related neuroinflammatory disorders, Parkinson’s diseases, multiple system atrophy, spinal cord injury, dementia, peripheral neuropathy, and others. Concurrently, we also summarized the hypothetical reasonings and available animal models to elucidate the underlying mechanism of neurogenic OAB symptoms. This review highlighted the close association between OAB symptoms and neurological diseases and expanded the current knowledge of pathophysiological basis of OAB. This may increase the awareness of urological complaints in neurological disorders and inspire robust therapies with better outcomes.

Baseline Brain Segmental Volumes in Responders and Nonresponders to Anticholinergic Therapy for Overactive Bladder Syndrome

OBJECTIVE

Evaluate structural differences in brains of responders (R) and nonresponders (NR) to anticholinergic (AC) therapy for overactive bladder (OAB).

MATERIALS AND METHODS

This was a retrospective cohort study of age matched women treated with an AC medication for OAB and underwent magnetic resonance imaging within 12 months before treatment. Data on pretreatment demographic and clinical variables and symptom severity was also collected.T1-weighted magnetic resonance images of the brain for each subject were segmented using FreeSurfer software. Structures included for analysis were cerebral cortex, white matter, subcortical gray matter, cerebellum, and brain stem.Nonresponders were defined as patients who reported less than 50% improvement after a minimum of 4 weeks on the maximum dose of the prescribed medication. Pairwise analysis between groups was performed using the Wilcoxon-Rank Sum test and Fisher exact test where appropriate. Spearman ρ was used to evaluate for correlations between neurologic structures and symptom severity.

RESULTS

There were no differences in pretreatment characteristics or symptom severity between the 21 R and 18 NR. Nonresponders had lower volumes of the right caudal anterior cingulate gyrus white matter (1919 mm3 vs 2416 mm3, P = 0.008) and right parahippocampal gyrus white matter (1008 mm3 vs 1469 mm3, P = 0.001). Incontinence episode frequency showed a negative moderate correlation with the anterior cingulate gyrus white matter volume (ρ = -0.4228, P = 0.007). The right and left cerebellar cortices showed weak and moderate negative correlations to frequency of nocturia (ρ = -0.384, P = 0.02 and ρ -0.443, P = 0.005, respectively).

CONCLUSION

There are measurable volumetric differences in brain structures in R and NR to AC therapy.

The Relationship Between Lower Urinary Tract Symptoms and Severity of Alzheimer's Disease

INTRODUCTION

Urinary incontinence (UI) is more prevalent in elderly populations with dementia than those without dementia. Alzheimer's disease (AD) is the most common cause of dementia. Urge UI, the most common type of UI in AD patients, causes more morbidity and mortality. However, it is inconvenient to obtain the report of urodynamic study from AD patient to diagnose urinary incontinence. Nevertheless, it is easier to obtain subjective or objective questionnaires from the patients or the caregivers. The data collected from the questionnaires are used to evaluate if severity of dementia is associated with urge UI and other lower urinary tract symptoms (LUTs).

PATIENTS AND METHODS

A total of 43 AD patients were enrolled in this study, all of whom were checked post-void residual (PVR) urine amount by sonography after voiding. The severity of dementia was evaluated by questionnaire including Cognitive Abilities Screening Instrument (CASI), Mini Mental Status Examination (MMSE), Clinical Dementia Rating (CDR), and Clinical Dementia Rating Sub-of-Box (CDR-SB). The LUTs were assessed with International Consultation of Incontinence Questionnaire (ICIQ) and Overactive bladder symptom scores (OABSS) questionnaire. Independent t test and Pearson's correlation analysis were calculated.

RESULTS

The average age in both AD with/without urge UI patients is 78 years old. The scores of CDR-SB, OABSS and ICIQ are significantly different in these 2 groups (p = 0.023, p = 0.003, p = 0.001; respectively). However, the neurophysiological scores of CASI, MMSE, CDR, CDR-SB is not correlated with OABSS (r = 0.047, p = 0.382; r = 0.074, p = 0.317; r = 0.087, p = 0.288; r = 0.112, p = 0.237; respectively). Interestingly, if we separate each individual symptom of OAB, there is a significant correlation between CDR-SB and urge UI score (r = 0.314, p = 0.023).

CONCLUSIONS

Higher lower urinary tract symptom scores are noted in AD patients with urge UI. The CDR-SB score is highly correlated with urge UI in AD patients.

Lower urinary tract function in frontotemporal lobar degeneration: A preliminary observation

OBJECTIVE

The urodynamics underlying lower urinary tract (LUT) dysfunction in frontotemporal lobar degeneration (FTLD) has not been reported. Herein, we investigated LUT function in FTLD patients by performing a urodynamics analysis.

PATIENTS AND METHODS

We recruited five FTLD patients with LUT symptoms: three men, two women; mean age, 70.4 years; mean disease duration, 3.8 years; mean Hoehn-Yahr grade 1.0. We administered a urinary symptom questionnaire and performed a urodynamics study in each patient.

RESULTS

LUT symptoms were observed in all patients. Urinary urgency/frequency (also called overactive bladder, OAB) was noted in all; OAB wet in three (60%) and mild voiding difficulty in two (40%). The urodynamic abnormalities included detrusor overactivity in four (80%), increased bladder sensation in two, large post-void residual in one (comorbid spondylosis), and latent detrusor underactivity in two. None had apparent outlet obstruction or detrusor-sphincter dyssynergia. Sphincter electromyography was normal in the cases studied.

CONCLUSION

We observed detrusor overactivity in FTLD patients with LUT symptoms. Although a preliminary observation, this LUT feature, which might reflect the frontal/insular cortex pathology typically associated with FTLD, requires appropriate management and care.

Urodynamic Assessment of Neuronal Intranuclear Inclusion Disease

Neuronal intranuclear inclusion disease (NIID) is a disease that causes leukoencephalopathy (dementia) and peripheral neuropathy (variable manifestation including bladder dysfunction). This is the first urodynamic report to show that bladder dysfunction in NIID is a combination of detrusor overactivity, decreased bladder sensation, large post-void residual, and neurogenic changes in the sphincter electromyogram. This report will help managing bladder dysfunction in NIID.

Toileting-related falls at night in hospitalised patients: The role of nocturia

OBJECTIVE

The purpose of this study was to describe the prevalence and characteristics of toileting-related falls in hospitalised older people.

METHODS

Retrospective analysis of falls related to night-time toileting in patients 60 years or over in a tertiary hospital during a one-year period.

RESULTS

Overall 34% of falls were related to toileting with at least 44% of these falls occurring during the night. Toilet-related falls peaked between 11 pm and 1 am, a period that coincides with maximum supine-induced diuresis. Almost half of night falls occurred at the bedside. In 80% of night toileting-related falls, patients were mobilising without the recommended level of assistance. Half of all patients had no strategies for toileting documented in their care plan.

CONCLUSION

Findings support screening for nocturia in older inpatients and implementation of strategies to reduce both the need for toileting at night and risk factors for falling.

The association between lower urinary tract symptoms and falls: Forming a theoretical model for a research agenda

BACKGROUND

There is a well-recognised association between falls and lower urinary tract symptoms (LUTS) in older adults, with estimates of odd ratios for falls in the presence of LUTS ranging between 1.5 and 2.3. Falls and LUTS are both highly prevalent among older people and both are markers of frailty, with significant associated morbidity, mortality, and healthcare resource cost. This association is not well examined or explained in the literature.

AIMS

We aimed to outline current knowledge of the association between falls and lower urinary tract symptoms and suggest a research program to further investigate this.

MATERIALS AND METHODS

A consensus conference of experts in the field was convened to review the current literature and brainstorm potential future investigative avenues.

RESULTS AND DISCUSSION

Despite the recognition of this association, there has been little research to examine its potential causes, and no intervention trial has established if reducing LUTS or urinary incontinence can reduce the risk of falls. The commonly held assumption that urgency causes falls through rushing to the toilet is likely incorrect. Falls and LUTS are both symptoms of frailty and have many common causes. Gait, balance, and continence are all processes requiring cognitive input, and the concept of dual tasking may be a further link.

CONCLUSION

The significant association between lower urinary tract symptoms and falls is currently unexplained, and further research into the potential causes of this association is needed.

Urinary Incontinence in Alzheimer's Disease

OBJECTIVES

Urinary incontinence (UI) is more prevalent in the elderly populations with dementia than without dementia, and Alzheimer's disease (AD) is the most common cause of dementia. Urinary incontinence may complicate AD morbidity and mortality. Therefore, this study aimed to evaluate the prevalence and annual incidence and determine the risk possibility of UI, which is the main type of incontinence in patients with AD in Taiwan.

METHODS

A total of 933 patients with AD were included in the study cohort, and a total of 2799 patients without AD by 1:3 proportion compared to the study cohort were used as a matched cohort. All participants were selected from the National Health Insurance Research Database in 2000 sample population. We utilize Cox proportional hazard regression to evaluate the risk of UI and cumulative incidence ratio curve to analyze the cumulative incidence function. Prevalence and annual incidence rate are calculated in individual medication including rivastigmine, donepezil, galantamine, and memantine only being initiated in patients with AD.

RESULTS

The risk of UI is higher in AD cohort (hazard ratio: 1.54, 95% confidence interval: 1.13-2.09). The cumulative incidence ratio of UI event between AD cohort and matched cohort presents statistical significance ( P < .001). Annual incidence and prevalence of UI in patients with AD are 6.2% and 4.2%, respectively.

CONCLUSION

The present results suggest that the risk of UI is higher in patients with AD than in the general population.

Correlation between overactive bladder symptom score and neuropsychological parameters in Alzheimer's disease patients with lower urinary tract symptom

Purpose

To examine an association between the overactive bladder symptom score (OABSS) and neuropsychological parameters. Moreover, we investigate the factors that affect each item in the questionnaire.

Materials and Methods

A total of 376 patients (males: 184; females: 192) with probable Alzheimer’s disease (AD) were recruited. Cognitive testing was conducted using the Mini Mental Status Examination (MMSE), Clinical Dementia Rating (CDR) scale, Global Deterioration Scale (GDS), and Barthel Activities of Daily Living (ADL). Lower urinary tract symptom (LUTS) was assessed using OABSS and voiding diary.

Results

The prevalence of overactive bladder (OAB) (defined as OABSS ≥3 with an urgency score of ≥2) in patients with AD was 72.6%. Among the OAB subjects, the most common severity of symptom was moderate (72.6%), followed by mild (21.2%), and severe (5.8%). It was found that OABSS had a very high correlation with aging (r=0.75; p<0.001). When compared with neuropsychological parameters, it was found that OABSS was highly correlated with the CDR scores (r=0.446; p<0.001). However, no significant correlation was found between the changes in OABSS scores and those in other neuropsychological parameters. Based on the individual symptom scores, urgency incontinence was highly correlated with the CDR scores (r=0.43; p<0.001).

Conclusions

OABSS is a useful tool in assessing AD patients with LUTS. There was a consistent positive association between OABSS severity, including urgency incontinence, and CDR scores.

White matter hyperintensities and geriatric syndrome: An important role of arterial stiffness

White matter hyperintensities (WMH) are defined as cerebral white matter changes presumed to be of vascular origin, bilateral and mostly symmetrical. They can appear as hyperintense on T2-weighted and fluid-attenuated inversion recovery sequences, and as isointense or hypointense on T1-weighted magnetic resonance imaging of the brain. WMH have been focused on because of their clinical importance as a risk factor for cerebrovascular diseases and cognitive impairment. WMH are associated with geriatric syndrome, which is defined by clinical symptoms characteristic of older adults, including cognitive and functional impairment and falls. Cerebral small vessel diseases, such as WMH, might play an important role as risk factors for cerebrovascular diseases, cognitive impairment and geriatric syndrome through the mechanism of arterial stiffness. However, the vascular, physiological and metabolic roles of arterial stiffness remain unclear. Basically, arterial stiffness indicates microvessel arteriosclerosis presenting with vascular endothelial dysfunction. These changes might arise from hemodynamic stress as a result of a "tsunami effect" on cerebral parenchyma. In the present article, we review the clinical characteristics of WMH, focusing particularly on two associations: (i) those between cerebral small vessel diseases including WMH and arterial stiffness; and (ii) those between WMH and geriatric syndrome.

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.

Lower urinary tract function in dementia with Lewy bodies (DLB)

OBJECTIVES

Dementia with Lewy bodies (DLB) is the second most common degenerative cause of dementia, whereas lower urinary tract (LUT) function in DLB patients has not been fully delineated. We investigated LUT function in DLB by clinical-urodynamic observations.

METHODS

We examined 32 patients with DLB (23 men, 9 women; aged 59-86 [mean, 75.9] years; disease duration, 0.2-17 [3.3] years). All patients underwent an electromyography-cystometry, and 21 patients underwent the sphincter motor unit potential analysis.

RESULTS

Ninety-one percent of patients had LUT symptoms: nighttime frequency (>8 times), 84%, and urinary incontinence (>1 per week), 50%. Detrusor overactivity was revealed in 87.1%, whereas postvoid residual was minimal. Neurogenic changes were shown in 50%.

CONCLUSION

LUT dysfunction is a common feature in DLB, attributable not only to dementia and immobility, but also to central and peripheral types of somato-autonomic dysfunction.

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.