Changes in brain response to urgency before and after treatment of urgency urinary incontinence with onabotulinumtoxin A.

INTRODUCTION: To better understand the role of the brain in urgency urinary incontinence (UUI), we used onabotulinumtoxin A (BoNTA) as a probe to evaluate changes in the brain's response to urgency in successful and unsuccessful treatment. Because BoNTA acts peripherally, brain changes observed should represent a reaction to changes in bladder function caused by BoNTA, or changes in the brain's compensatory mechanisms, rather than a direct effect of BoNTA on the brain. METHODS: We recruited 20 women aged over 60 years with nonneurogenic UUI who were to undergo treatment with onabotulinum A toxin injected intravesically. We performed a baseline evaluation which included a 3-day bladder diary and functional magnetic resonance imaging with an urgency provocation task; we repeated this evaluation 6 weeks posttreatment. We performed an analysis of variance on a priori selected regions of interest and post hoc voxel-wise analysis on responders and nonresponders to treatment. RESULTS: We found a significant interaction in the right insula [F(1,18) = 5.5, p = 0.031]; activity was different during urgency provocation in responders and non-responders to therapy, before and after therapy. The supramarginal gyrus (SMG) and inferior frontal gyrus (IFG) also displayed significant interactions (p < 0.005). Activity in the periaqueductal gray and prefrontal cortex was correlated with number of leakage episodes (p < 0.05). CONCLUSION: The changes seen in the brain control mechanism after therapy likely reflect reduced bladder sensation caused by BoNTA's peripheral action. We ascribe the SMG and IFG changes to a coping mechanism for urgency which is reduced in those who respond well to treatment.

Testing a new, intensified infusion-withdrawal protocol for urinary urgency provocation in brain-bladder studies.

INTRODUCTION: The brain's role in bladder control has become an important area of study in the last 15 years. Typically, the brain's role in urinary urgency has been studied by repeated infusion and withdrawal of fluid, per catheter, to provoke urgency sensation during a whole brain magnetic resonance imaging (MRI) scan. Since this technique generally requires a large group size, we tested a more intense infusion-withdrawal protocol in an attempt to improve signal to noise ratio and repeatability of the signal which would, in turn, allow us to further probe subtypes of urgency urinary incontinence. METHODS: A total of 12 women over the age of 60 were recruited to test a new "intense" infusion withdrawal protocol. They underwent this new protocol during a functional brain MRI scan. The primary outcome was comparison of activity within the insula, medial pre-frontal cortex and dorsal anterior cingulate cortex/supplementary motor area (dACC/SMA). Immediate test-retest repeatability was measured using intraclass correlation. Secondary exploratory evaluation of differences in the whole brain between protocols was conducted. RESULTS: There was no significant difference in signal in any of the a priori regions of interest between protocols. Test-retest repeatability in the new protocol was poor compared to the original protocol, and variability was higher. Three participants were not able to tolerate the "intense" protocol. CONCLUSION: The small improvement in signal to noise ratio of the new protocol was not sufficient to overcome the poorly tolerated intense filling protocol.

Microbiology of acute bacterial skin and skin-structure infections in Greece: A proposed clinical prediction score for the causative pathogen.

Although clinical definitions of acute bacterial skin and skin-structure infection (ABSSSI) are now well established, guidance of the prediction of likely pathogens based on evidence is missing. This was a large survey of the microbiology of ABSSSIs in Greece. During the period November 2014 to December 2016, all admissions for ABSSSI in 16 departments of internal medicine or surgery in Greece were screened to determine the likely bacterial aetiology. Samples were cultured on conventional media. Expression of the SA442, mecA/mecC and SCCmec-orfX junction genes was assessed. Following univariate and forward logistic regression analysis, clinical characteristics were used to develop scores to predict the likely pathogen with a target of 90% specificity. In total, 1027 patients were screened and 633 had positive microbiology. Monomicrobial infection by Gram-positive cocci occurred in 52.1% and by Gram-negative bacteria in 20.5%, and mixed infection by Gram-positive cocci and Gram-negative bacteria in 27.3%. The most common isolated pathogens were Staphylococcus aureus and coagulase-negative staphylococci. Resistance to methicillin was 57.3% (53.5-61.1%). Three predictive scores were developed: one for infection by methicillin-resistant S. aureus, incorporating recent hospitalisation, atrial fibrillation, residency in long-term care facility (LTCF) and stroke; one for mixed Gram-positive and Gram-negative infections, incorporating localisation of ABSSSI in lumbar area, fluoroquinolone intake in last 6 days, residency in LTCF and stroke; and another for Gram-negative infection, incorporating skin ulcer presentation, peptic ulcer and solid tumour malignancy. In conclusion, methicillin-resistant staphylococci are the main pathogens of ABSSSIs. The scores developed may help to predict the likely pathogen.

Investigation of urinary storage symptoms in Parkinson's disease utilizing structural MRI techniques.

BACKGROUND: Lower urinary tract symptoms occur in 27% to 86% of patients with Parkinson's disease (PD), however, the mechanisms responsible for bladder dysfunction are not fully understood. This study utilized magnetic resonance imaging (MRI) to test the hypothesis that key brainstem bladder control areas (including the pontine micturition center and the pontine continence center (PCC) and their links with the basal ganglia are important in the development of urinary storage symptoms in PD. METHODS: Seventeen patients with PD completed a "bladder symptom questionnaire" and underwent diffusion-weighted MRI (1.5 T). Storage symptom severity and MRI measures of white matter microstructural integrity were correlated using tract-based spatial statistics. RESULTS: Mean diffusivity in the ventral brainstem correlated significantly with the bladder symptom severity in areas close to the predicted anatomical co-ordinates of the PCC. Tracts seeded from these regions passed via areas involved in pelvic floor musculature control and urinary voiding including the cerebellum, pallidum, and precentral gyrus. CONCLUSION: We used diffusion-weighted MRI to investigate the role of the brainstem and its structural connections in the development of urinary storage symptoms in PD. Our data suggest that the brainstem degenerative change in the vicinity of the PCC may be implicated in the pathogenesis of storage symptoms in these patients.

Functional connectivity of the brain in older women with urgency urinary incontinence.

BACKGROUND: The brain's role in continence is critical but poorly understood. Although regions activated during bladder stimulation have been identified, little is known about the interaction between regions. In this secondary analysis we evaluate resting state and effective connectivity in older women treated for urgency urinary incontinence (UUI). METHOD: 54 women ≥60 years old with UUI and 10 continent women underwent fMRI scanning during provocation of urinary urgency, both before and after therapy. Response was defined by >50% reduction in leaks on bladder diary. Regions of interest (RoIs) were selected a priori: right insula, medial prefrontal cortex, and dorsal anterior cingulate cortex. Generalized psycho-physiological interaction (gPPI) was used to calculate "effective connectivity" between RoIs during urgency. We performed a one-way ANOVA pre-treatment between groups (continent/responders/non-responders), as well as a two-way mixed ANOVA between group and time (responders/non-responders; pre-/post-therapy) using false discovery rate (FDR) correction. Principal component analysis was used to assess the variance within RoIs. Exploratory voxel-wise connectivity analyses were conducted between each RoI and the rest of the brain. RESULTS: RoI-RoI connectivity analysis showed connectivity differences between controls, responders, and non-responders, although statistical significance was lost after extensive correction. Principal component analysis confirmed appropriate RoI selection. Voxel-wise analyses showed that connectivity in responders became more like that of controls after therapy (cluster-wise correction P < 0.05). In non-responders, no consistent changes were seen. CONCLUSION: These data support the postulate that responders and non-responders to therapy may represent different subsets of UUI, one with more of a central etiology, and one without.

Do brain structural abnormalities differentiate separate forms of urgency urinary incontinence?

AIMS: Urgency urinary incontinence (UUI) is a major problem for seniors. The underlying mechanisms of disease and therapy are unknown. We sought structural brain abnormalities that might underlie the functional differences previously observed by functional Magnetic Resonance Imaging in UUI patients versus controls, or among UUI responders versus non-responders to therapy-and thereby reveal potential disease mechanisms and therapeutic targets. METHODS: Secondary study of a trial of biofeedback-assisted pelvic floor muscle training (BFB) in 60 women (>60 yrs) with UUI, plus 11 age-matched continent controls. Brain structural abnormalities were investigated using: (1) white-matter hyperintensities (WMH); (2) diffusion tensor imaging (DTI) to reveal white-matter pathways with impaired integrity; and (3) voxel-based morphometry (VBM) to show regions of atrophy or hypertrophy. RESULTS: WMH burden was greater in UUI patients than controls (globally and in superior longitudinal fasciculus and cingulum), suggesting a possible causal connection. WMH burden was unexpectedly greater in responders than non-responders to BFB, and appeared to increase in non-responders but not in responders. DTI revealed even worse integrity of the cingulum than was apparent by WMH. VBM showed parahippocampal atrophy in UUI. CONCLUSIONS: Many women with UUI have white-matter damage that interferes with pathways critical to bladder control; they can be taught by techniques like BFB to exert stronger control over the bladder. For others, in whom abnormalities of key brain areas are less marked, UUI's cause may reside elsewhere, and therapy targeting these brain centers may be less effective than therapy targeting the bladder or other brain centers.

Test-retest repeatability of patterns of brain activation provoked by bladder filling.

OBJECTIVE: To assess short-term repeatability of an fMRI protocol widely used to assess brain control of the bladder. fMRI offers the potential to discern incontinence phenotypes as well as the mechanisms mediating therapeutic response. If so, this could enable more targeted efforts to enhance therapy. Such data, however, require excellent test-retest repeatability. METHODS: Fifty-nine older women (age ≥60 years) with urgency incontinence underwent two fMRI scans within 5-10 min with a concurrent bladder infusion/withdrawal protocol. Activity in three brain regions relevant to bladder control was compared using paired t tests and intra-class correlation. RESULTS: There were no statistically significant differences in brain activity between the two consecutive scans in the regions of interest. Intra-class correlation was 0.19 in the right insula, 0.32 in the dorsal anterior cingulate cortex/supplementary motor area, and 0.44 in the medial pre-frontal cortex. Such correlations are considered fair or poor, but are comparable to those from studies of other repeated fMRI tasks. CONCLUSIONS: This is the first evaluation of the repeatability of a bladder fMRI protocol. The technique used provides a framework for comparing different fMRI protocols applied to brain-bladder research. Despite universal patient response to the stimulus, brain response had limited repeatability within individuals. Improvement of the investigational protocol should magnify brain response and reduce variability. These results suggest that although analysis of fMRI data among groups of subjects yields valuable insight into bladder control, fMRI is not yet appropriate for evaluation of the brain's role in continence on an individual level.

Neural control of micturition in humans: a working model.

Results from functional brain scanning have shown that neural control of the bladder involves many different regions. Yet, many aspects of this complex system can be simplified to a working model in which a few forebrain circuits, acting mainly on the midbrain periaqueductal grey (PAG), advance or delay the triggering of the voiding reflex and generate bladder sensations according to the volume of urine in the bladder, the safety of voiding and the emotional and social propriety of doing so. Understanding these circuits seems to offer a route to treatment of conditions, such as urgency incontinence or overactive bladder, in patients without overt neurological disease. Two of these circuits include, respectively, the medial prefrontal cortex and the parahippocampal complex, as well as the PAG. These circuits belong to a well-known network that is active at rest and deactivated when attention is required. Another circuit, comprising the insula and the midcingulate or dorsal anterior cingulate cortex, is activated by bladder filling and belongs to a salience network that generates sensations such as the desire to void. Behavioural treatments of urgency incontinence lead to changes in brain function that support the working model and suggest the mechanism of this type of treatment.

Functional Brain Imaging and the Neural Basis for Voiding Dysfunction in Older Adults.

Brain abnormalities may contribute to the increased prevalence of urinary dysfunction such as overactive bladder and urge incontinence in older individuals. Functional brain imaging suggests that 3 independent neural circuits (frontal, midcingulate, and subcortical) control voiding by suppressing the voiding reflex in the brainstem periaqueductal gray. Damage to the connecting pathways subserving these circuits (white matter hyperintensities) increases with age and is associated both with severity of urge incontinence and changes in brain function. Multicomponent therapies targeting structural and functional neural abnormalities may be more effective than any single treatment focused on the bladder.

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.

Brain Mechanisms Underlying Urge Incontinence and its Response to Pelvic Floor Muscle Training.

PURPOSE: Urge urinary incontinence is a major problem, especially in the elderly, and to our knowledge the underlying mechanisms of disease and therapy are unknown. We used biofeedback assisted pelvic floor muscle training and functional brain imaging (functional magnetic resonance imaging) to investigate cerebral mechanisms, aiming to improve the understanding of brain-bladder control and therapy. MATERIALS AND METHODS: Before receiving biofeedback assisted pelvic floor muscle training functionally intact, older community dwelling women with urge urinary incontinence as well as normal controls underwent comprehensive clinical and bladder diary evaluation, urodynamic testing and brain functional magnetic resonance imaging. Evaluation was repeated after pelvic floor muscle training in those with urge urinary incontinence. Functional magnetic resonance imaging was done to determine the brain reaction to rapid bladder filling with urgency. RESULTS: Of 65 subjects with urge urinary incontinence 28 responded to biofeedback assisted pelvic floor muscle training with 50% or greater improvement of urge urinary incontinence frequency on diary. However, responders and nonresponders displayed 2 patterns of brain reaction. In pattern 1 in responders before pelvic floor muscle training the dorsal anterior cingulate cortex and the adjacent supplementary motor area were activated as well as the insula. After the training dorsal anterior cingulate cortex/supplementary motor area activation diminished and there was a trend toward medial prefrontal cortex deactivation. In pattern 2 in nonresponders before pelvic floor muscle training the medial prefrontal cortex was deactivated, which changed little after the training. CONCLUSIONS: In older women with urge urinary incontinence there appears to be 2 patterns of brain reaction to bladder filling and they seem to predict the response and nonresponse to biofeedback assisted pelvic floor muscle training. Moreover, decreased cingulate activation appears to be a consequence of the improvement in urge urinary incontinence induced by training while prefrontal deactivation may be a mechanism contributing to the success of training. In nonresponders the latter mechanism is unavailable, which may explain why another form of therapy is required.

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.

International Continence Society guidelines on urodynamic equipment performance.

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice.

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.

What predicts and what mediates the response of urge urinary incontinence to biofeedback?

AIMS: To better target a behavioral approach for urge urinary incontinence (UUI) and enhance its efficacy by (1) identifying predictors of response to biofeedback-assisted pelvic muscle training (BFB), and (2) determining factors that mediate response. METHODS: BFB (four biweekly visits) was administered to 183 women > 60 years (mean = 73.6). Before and after intervention, all underwent comprehensive evaluation and videourodynamic testing. Postulated predictors and mediators from four urodynamic domains, specified a priori, were correlated with reduction in UUI frequency. RESULTS: Median UUI frequency decreased from 3.2/day to 1/day (P =0.0001). UUI improved by ≥50% in 55% of subjects and by 100% in 13% of subjects. Frequent UUI predicted poor response (P < 0.01). Of the urodynamic parameters, only high amplitude and briskness of detrusor overactivity (DO) predicted decreased response (P < 0.05 and P < 0.01) and these could be measured only in the 43% of subjects with elicitable DO. Decreased DO elicitability was the only urodynamic variable that changed in concert with improvement and thus was a candidate mediator. Response was neither predicted nor mediated by proprioception/warning, cystometric capacity, detrusor contractility, sphincter strength, or baseline DO elicitability. CONCLUSIONS: Severe DO predicts poor response to BFB. Good response is mediated by reduction in DO elicitability. Other than baseline UUI frequency, there are no other clinically or urodynamically important predictors or mediators of BFB response in this population. BFB may be best for patients with less severe DO. Future research to enhance its efficacy might better focus on the brain than on the lower urinary tract.

The CNS and bladder dysfunction.

The brain's role in the development and maintenance of bladder control is critical, although its precise role in patient-reported complaints such as urgency and urine leakage is unknown. Functional brain imaging studies have advanced our knowledge of brain activity during the micturition cycle, showing multiple neuronal circuits involved as parts of a 'brain-bladder control network.' Yet, new advances need to be made in order to incorporate this knowledge into existing models of neuroanatomy and of clinical syndromes of bladder dysfunction and related clinical practice. This short article explains why and how brain imaging methods are poised to achieve that goal and decode the role of the brain in widely prevalent clinical conditions related to bladder dysfunction.

Brain activity underlying impaired continence control in older women with overactive bladder.

AIMS: To identify, in subjects with overactive bladder (OAB), differences in brain activity between those who maintained and those who lost bladder control during functional magnetic resonance imaging (fMRI) of the brain with simultaneous urodynamics. METHODS: Secondary analysis of a cohort of older women (aged >60) with proven urgency urinary incontinence, who, in the scanner, either developed detrusor overactivity and incontinence (the "DO group") or did not (the "no DO" group). A priori hypothesis: during urgency provoked by bladder filling, without DO, activity in regions related to continence control is diminished in the DO group; specifically (1a) less activation in supplementary motor area (SMA) and (1b) less deactivation in prefrontal cortex (PFC) and parahippocampal complex (PH). We also explored phenotypic (clinical and urodynamic) differences between the groups. RESULTS: During urgency preceding DO, the DO group showed stronger activation in SMA and adjacent regions (hypothesis 1a rejected), and less deactivation in PH but no significant difference in PFC (hypothesis 1b partially accepted). These subjects were older, with more changes in brain's white matter, decreased tolerance of bladder filling and greater burden of incontinence. CONCLUSIONS: (1) In older women with OAB, brain activity in the SMA is greater among those with more easily elicitable DO, suggesting a compensatory response to failure of control elsewhere. (2) OAB is heterogeneous; one possible phenotype shows severe functional impairment attributable partly to age-related white matter changes. (3) Functional brain imaging coupled with urodynamics may provide CNS markers of impaired continence control in subjects with OAB.

Use of functional imaging to monitor central control of voiding in humans.

Bladder problems are frequently disorders of control, which is exercised from the brain. In such disorders, brain responses to bladder events are abnormal; therapy is accompanied by regional changes that may be measured by functional imaging and used to monitor the effect of treatment. The regional responses may be understood in terms of a tentative model of the bladder control system. The model helps also to interpret alterations in brain behavior (as imaged by functional scanning) that occur when afferent signals from bladder or urethra are changed experimentally or by an underlying disorder or treatment, for example, overactive bladder (urge/urgency incontinence). Successful treatment may either increase the ability to cope with the problem or may be curative. The direction of treatment-induced change of abnormal brain responses can distinguish these two possibilities and shed light on the therapeutic mechanism. In addition, brain activity in regions such as insula or dorsal anterior cingulate cortex may be regarded as a proxy for sensations such as desire to void or urgency, which are otherwise difficult to define or measure. Monitoring of brain responses in these regions offers an obvious way to test the effect of drugs.