Functional Magnetic Resonance Imaging with Concurrent Urodynamic Testing Identifies Brain Structures Involved in Micturition Cycle in Patients with Multiple Sclerosis

Functional neuroimaging related to lower urinary tract sensations: Future directions for study designs and selection of patient groups: ICI-RS 2023

OBJECTIVES

Neuroimaging studies have advanced our understanding of the intricate central nervous system control network governing lower urinary tract (LUT) function, shedding light on mechanisms for urine storage and voiding. However, a lack of consensus in methodological approaches hinders the comparability of results among research groups and limits the translation of this knowledge to clinical applications, emphasizing the need for standardized methodologies and clinical utilization guidelines.

METHODS

This paper reports the discussions of a workshop at the 2023 meeting of the International Consultation on Incontinence Research Society, which reviewed uncertainties and research priorities to progress the field of neuroimaging in LUT control and dysfunction.

RESULTS

Neuroimaging holds great potential for improving our understanding of LUT control and pathophysiological conditions. To date, functional neuroimaging techniques have not yet achieved sufficient strength to make a direct clinical impact. Potential approaches that can improve the clinical utilization of neuroimaging were discussed and research questions proposed.

CONCLUSIONS

Neuroimaging offers a valuable tool for investigating LUT control, but it's essential to acknowledge the potential for oversimplification when interpreting brain activity due to the complex neural processing and filtering of sensory information. Moreover, technical limitations pose challenges in assessing key brain stem and spinal cord centers, particularly in cases of neurological dysfunction, highlighting the need for more reliable imaging of these centers to advance our understanding of LUT function and dysfunction.

Could a better understanding of the underlying pathophysiologies lead to more informed treatment choices in patients with lower urinary tract dysfunction due to an acontractile or underactive detrusor? ICI-RS 2023

INTRODUCTION

The underlying pathophysiology behind a diagnosis of acontractile or underactive detrusor at invasive urodynamics is very heterogeneous. Lack of etiological classification currently limits the possibility of stratifying therapy.

METHODS

This subject was discussed at a think-tank on the subject at the International Consultation on Incontinence-Research Society held in Bristol, June 2023. This manuscript is a result of those deliberations and the subsequent discussions of the think-tank.

RESULTS

There are challenges in defining abnormalities of detrusor contraction with resultant implications for available evidence. Pathology at any level of the neuromuscular pathway can impair or prevent a detrusor voiding contraction. Attempts have been made to identify clinical markers that might predict an underactive detrusor but strong supporting evidence is lacking. Hence, a holistic approach to phenotyping requires specialized neuro-imaging as well as physiological investigations. Several general measures can help individuals with an abnormal detrusor contraction. The search for a molecule to enhance the detrusor voiding contraction remains elusive but there are promising new candidates. Neuromodulation can help select individuals but data is not well stratified by underlying etiology. Manipulation of central neurotransmitters might offer an alternate therapeutic option.

CONCLUSIONS

A better understanding of the underlying pathophysiologies behind an abnormality of the detrusor voiding contraction is needed for improving management. Towards this goal, the think-tank proposes a classification of the underactive detrusor that might help in selecting and reporting more well-defined patient cohorts.

Brain Responses Difference between Sexes for Strong Desire to Void: A Functional Magnetic Resonance Imaging Study in Adults Based on Graph Theory

Background: The alternations of brain responses to a strong desire to void were unclear, and the gender differences under the strong desire to void remain controversial. The present study aims to identify the functional brain network's topologic property changes evoked by a strong desire to void in healthy male and female adults with synchronous urodynamics using a graph theory analysis. Methods: The bladders of eleven healthy males and eleven females were filled via a catheter using a specific infusion and withdrawal pattern. A resting-state functional magnetic resonance imaging (fMRI) was performed on the enrolled subjects, scanning under both the empty bladder and strong desire to void states. An automated anatomical labeling (AAL) atlas was used to identify the ninety cortical and subcortical regions. Pearson's correlation calculations were performed to establish a brain connection matrix. A paired t-test (p < 0.05) and Bonferroni correction were applied to identify the significant statistical differences in topological properties between the two states, including small-world network property parameters [gamma (γ) and lambda (λ)], characteristic path length (Lp), clustering coefficient (Cp), global efficiency (Eglob), local efficiency (Eloc), and regional nodal efficiency (Enodal). Results: The final data suggested that females and males had different brain response patterns to a strong desire to void, compared with an empty bladder state. Conclusions: More brain regions involving emotion, cognition, and social work were active in females, and males might obtain a better urinary continence via a compensatory mechanism.

Cerebellar functional connectivity relates to lower urinary tract function: A 7 Tesla study

OBJECTIVES

The objective of this study is to explore the functional connectivity (FC) of the cerebellum during the storage phase of micturition, through detecting spontaneous blood-oxygen-level dependent signal between the cerebellum and different brain regions using a high-resolution 7 Tesla magnetic resonance imaging (MRI) scanner.

MATERIALS AND METHODS

We recruited healthy individuals with no reported history of neurological disease or lower urinary tract (LUT) symptoms. Participants were asked to drink 500 mL of water and then empty their bladders before entering the MRI scanner. They underwent a T1-weighted anatomical scan, followed by an initial (8 min) empty bladder resting state functional MRI (rs-fMRI) acquisition. Once subjects felt the desire to void, a second rs-fMRI scan was obtained, this time with a full bladder state. We established a priori cerebellar regions of interest from the literature to perform seed-to-voxel analysis using nonparametric statistics based on the Threshold Free Cluster Enhancement method and utilized a voxel threshold of p < 0.05.

RESULTS

Twenty individuals (10 male and 10 female) with a median age of 25 years (IQR [3.5]) participated in the study. We placed 31 different 4-mm spherical seeds throughout the cerebellum and assessed their FC with the remainder of the brain. Three of these (left cerebellar tonsil, right posterolateral lobe, right posterior lobe) showed significant differences in connectivity when comparing scans conducted with a full bladder to those with an empty bladder. Additionally, we observed sex differences in FC, with connectivity being higher in women during the empty bladder condition.

CONCLUSION

Our initial findings reveal, for the first time, that the connectivity of the cerebellar network is modulated by bladder filling and is associated with LUT function. Unraveling the cerebellum's role in bladder function lays the foundation for a more comprehensive understanding of urinary pathologies affecting this area.

Evaluating noninvasive brain stimulation to treat overactive bladder in individuals with multiple sclerosis: a randomized controlled trial protocol

BACKGROUND

Multiple Sclerosis (MS) is an often debilitating disease affecting the myelin sheath that encompasses neurons. It can be accompanied by a myriad of pathologies and adverse effects such as neurogenic lower urinary tract dysfunction (NLUTD). Current treatment modalities for resolving NLUTD focus mainly on alleviating symptoms while the source of the discomfort emanates from a disruption in brain to bladder neural circuitry. Here, we leverage functional magnetic resonance imaging (fMRI), repetitive transcranial magnetic stimulation (rTMS) protocols and the brains innate neural plasticity to aid in resolving overactive bladder (OAB) symptoms associated with NLUTD.

METHODS

By employing an advanced neuro-navigation technique along with processed fMRI and diffusion tensor imaging data to help locate specific targets in each participant brain, we are able to deliver tailored neuromodulation protocols and affect either an excitatory (20 min @ 10 Hz, applied to the lateral and medial pre-frontal cortex) or inhibitory (20 min @ 1 Hz, applied to the pelvic supplemental motor area) signal on neural circuitry fundamental to the micturition cycle in humans to restore or reroute autonomic and sensorimotor activity between the brain and bladder. Through a regimen of questionnaires, bladder diaries, stimulation sessions and analysis, we aim to gauge rTMS effectiveness in women with clinically stable MS.

DISCUSSION

Some limitations do exist with this study. In targeting the MS population, the stochastic nature of MS in general highlights difficulties in recruiting enough participants with similar symptomology to make meaningful comparisons. As well, for this neuromodulatory approach to achieve some rate of success, there must be enough intact white matter in specific brain regions to receive effective stimulation. While we understand that our results will represent only a subset of the MS community, we are confident that we will accomplish our goal of increasing the quality of life for those burdened with MS and NLUTD.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov (NCT06072703), posted on Oct 10, 2023.

Classification of multiple sclerosis women with voiding dysfunction using machine learning: Is functional connectivity or structural connectivity a better predictor?

Introduction

Machine learning (ML) is an established technique that uses sets of training data to develop algorithms and perform data classification without using human intervention/supervision. This study aims to determine how functional and anatomical brain connectivity (FC and SC) data can be used to classify voiding dysfunction (VD) in female MS patients using ML.

Methods

Twenty-seven ambulatory MS individuals with lower urinary tract dysfunction were recruited and divided into two groups (Group 1: voiders [V, n = 14]; Group 2: VD [n = 13]). All patients underwent concurrent functional MRI/urodynamics testing.

Results

Best-performing ML algorithms, with highest area under the curve (AUC), were partial least squares (PLS, AUC = 0.86) using FC alone and random forest (RF) when using SC alone (AUC = 0.93) and combined (AUC = 0.96) as inputs. Our results show 10 predictors with the highest AUC values were associated with FC, indicating that although white matter was affected, new connections may have formed to preserve voiding initiation.

Conclusions

MS patients with and without VD exhibit distinct brain connectivity patterns when performing a voiding task. Our results demonstrate FC (grey matter) is of higher importance than SC (white matter) for this classification. Knowledge of these centres may help us further phenotype patients to appropriate centrally focused treatments in the future.

Predictors for outcomes of noninvasive, individualized transcranial magnetic neuromodulation in multiple sclerosis women with neurogenic voiding dysfunction

Purpose

Multiple sclerosis (MS) is a multifocal demyelinating disease that affects the central nervous system (CNS) and commonly leads to neurogenic lower urinary tract dysfunction (NLUTD). Proper storage and release of urine relies on synchronized activity of the LUT, which is meticulously regulated by supraspinal circuits, making it vulnerable to diseases such as MS. NLUTD, characterized by voiding dysfunction (VD), storage issues, or a combination of both is a common occurrence in MS. Unfortunately, there are limited treatment options for NLUTD, making the search for alternative treatments such as transcranial rotating permanent magnet stimulation (TRPMS) of utmost importance. To assess effectiveness of treatment we also need to understand underlying factors that may affect outcomes, which we addressed here.

Methods

Ten MS subjects with VD and median age of 54.5 years received daily TRPMS sessions for two weeks. Five pre-determined regions of interest (ROIs) known to be involved in the micturition cycle were modulated (stimulated or inhibited) using TRPMS. Clinical data (non-instrumented uroflow and urodynamics parameters, PVR, bladder symptom questionnaires) and neuro-imaging data were collected at baseline and following TRPMS via 7-Tesla Siemens MAGNETOM Terra magnetic resonance imaging (MRI) scanner. Each participant underwent functional MRI (fMRI) concurrently with a repeated urodynamic study (UDS). Baseline data of each arm was evaluated to determine any indicators of successful response to treatment.

Supraspinal Neural Changes in Men with Benign Prostatic Hyperplasia Undergoing Bladder Outlet Procedures: a Pilot Functional MRI Study

OBJECTIVE

To explore brain activation patterns on functional MRI (fMRI) in men with BPH and BOO before and after outlet obstruction procedures.

METHODS

Men age ≥ 45 who failed conservative BPH therapy planning to undergo BOO procedures were recruited. Eligible men underwent a concurrent fMRI/urodynamics testing before and six months after BOO procedure. fMRI images were obtained via 3 Tesla MRI. Significant blood-oxygen-level-dependent (BOLD) signal activated voxels (p<0.05) were identified at strong desire to void and (attempt at) voiding initiation pre and post BOO procedure.

RESULTS

Eleven men were enrolled, of which seven men completed the baseline scan, and four men completed the six-month follow-up scan. Baseline decreased BOLD activity was observed in right inferior frontal gyrus (IFG), bilateral insula, inferior frontal gyrus (IFG) and thalamus. Significant changes in BOLD signal activity following BOO procedures were observed in the insula, IFG, and cingulate cortices.

CONCLUSIONS

This represents a pilot study evaluating cortical activity in men with BPH and BOO. Despite limitations we found important changes in supraspinal activity in men with BPH and BOO during filling and emptying phases at baseline and following BOO procedure, with the potential to improve our understanding of neuroplasticity secondary to BPH and BOO. This preliminary data may serve as the foundation for larger future trials.

Preliminary Analysis of Brain Footprints in Multiple Sclerosis Females with Detrusor Sphincter Dyssynergia: A Concurrent Urodynamic and Functional Magnetic Resonance Imaging Study

Purpose

This study evaluates the grey and white brain matter characteristics in women with multiple sclerosis (MS) and detrusor sphincter dyssynergia (DSD). Grey matter is assessed via the functional connectivity (FC) of brain regions activated during voiding, using functional magnetic resonance imaging (fMRI). Two white matter tracts involved in bladder function, the anterior thalamic radiation (ATR) and superior longitudinal fasciculus (SLF), were evaluated using diffusion tensor imaging (DTI).

Methods

Twenty-seven women with MS (two groups: no-DSD (n=23) or DSD (n=4)), and eight healthy controls (HC) underwent concurrent urodynamic-fMRI evaluation with four cycles of bladder filling and emptying. A FC similarity measure (FC_sim) was calculated for each subject to express the similarity of individual FC at voiding initiation compared to all FC patterns. ATR and SLF tracts were traced and their fractional anisotropy (FA) and mean diffusivity (MD) were recorded.

Results

Mean FC_sim values were significantly different among the three groups indicating distinct FC patterns; however, no significant difference was found between DSD and no-DSD groups. DSD group showed trends of lower FA and higher MD - indicating loss of coherence - in all tracts compared to HCs, and in the left and right ATR when compared to MS women with neither DSD nor voiding dysfunction (VD), suggesting more damage in these tracts for MS women with DSD.

Conclusions

Women with MS show distinctly different FC patterns compared to HCs. There are trends showing more damage in the ATR in women with MS and DSD compared to those with neither DSD nor VD.

A systematic review and activation likelihood estimation meta-analysis of the central innervation of the lower urinary tract: Pelvic floor motor control and micturition

Purpose

Functional neuroimaging is a powerful and versatile tool to investigate central lower urinary tract (LUT) control. Despite the increasing body of literature there is a lack of comprehensive overviews on LUT control. Thus, we aimed to execute a coordinate based meta-analysis of all PET and fMRI evidence on descending central LUT control, i.e. pelvic floor muscle contraction (PFMC) and micturition.

Materials and methods

A systematic literature search of all relevant libraries was performed in August 2020. Coordinates of activity were extracted from eligible studies to perform an activation likelihood estimation (ALE) using a threshold of uncorrected p <0.001.

Results

20 of 6858 identified studies, published between 1997 and 2020, were included. Twelve studies investigated PFMC (1xPET, 11xfMRI) and eight micturition (3xPET, 5xfMRI). The PFMC ALE analysis (n = 181, 133 foci) showed clusters in the primary motor cortex, supplementary motor cortex, cingulate gyrus, frontal gyrus, thalamus, supramarginal gyrus, and cerebellum. The micturition ALE analysis (n = 107, 98 foci) showed active clusters in the dorsal pons, including the pontine micturition center, the periaqueductal gray, cingulate gyrus, frontal gyrus, insula and ventral pons. Overlap of PFMC and micturition was found in the cingulate gyrus and thalamus.

Conclusions

For the first time the involved core brain areas of LUT motor control were determined using ALE. Furthermore, the involved brain areas for PFMC and micturition are partially distinct. Further neuroimaging studies are required to extend this ALE analysis and determine the differences between a healthy and a dysfunctional LUT. This requires standardization of protocols and task-execution.

High spatial correlation in brain connectivity between micturition and resting states within bladder-related networks using 7 T MRI in multiple sclerosis women with voiding dysfunction

Background

Several studies have reported brain activations and functional connectivity (FC) during micturition using functional magnetic resonance imaging (fMRI) and concurrent urodynamics (UDS) testing. However, due to the invasive nature of UDS procedure, non-invasive resting-state fMRI is being explored as a potential alternative. The purpose of this study is to evaluate the feasibility of utilizing resting states as a non-invasive alternative for investigating the bladder-related networks in the brain.

Methods

We quantitatively compared FC in brain regions belonging to the bladder-related network during the following states: ‘strong desire to void’, ‘voiding initiation (or attempt at voiding initiation)’, and ‘voiding (or continued attempt of voiding)’ with FC during rest in nine multiple sclerosis women with voiding dysfunction using fMRI data acquired at 7 T and 3 T.

Results

The inter-subject correlation analysis showed that voiding (or continued attempt of voiding) is achieved through similar network connections in all subjects. The task-based bladder-related network closely resembles the resting-state intrinsic network only during voiding (or continued attempt of voiding) process but not at other states.

Conclusion

Resting states fMRI can be potentially utilized to accurately reflect the voiding (or continued attempt of voiding) network. Concurrent UDS testing is still necessary for studying the effects of strong desire to void and initiation of voiding (or attempt at initiation of voiding).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-021-03599-4.

The effect of stroke on micturition associated brain activity: A pilot fMRI study

OBJECTIVE

Cerebral stroke is a unique model for studying the role of the brain in lower urinary tract (LUT) control. By its nature, stroke must change the activity of the brain to cause LUT dysfunction. The objective of this study was to describe changes in micturition-related brain activity in patients who develop LUT symptoms (LUTS) after a cerebral stroke.

MATERIALS AND METHODS

Healthy controls (HC, n = 10) and patients who developed storage LUTS after a cerebral stroke (n = 7) were recruited. Functional magnetic resonance imaging was used to assess brain activity in each subject. In the task-based block design, blood-oxygen-level-dependent (BOLD) signal was detected during rest, active bladder filling, and bladder voiding. BOLD signal intensity was compared between HCs and stroke subjects during bladder filling, voiding, and voiding initiation.

RESULTS

Stroke subjects exhibited higher activity in the periaqueductal gray and cerebellum during bladder filling and bladder voiding. HCs exhibited more intense activity in higher centers, such as the cingulate cortex, motor cortex, and the dorsolateral prefrontal cortex in each of the phases examined.

CONCLUSIONS

Subjects with stroke-related LUTS exhibit a specific pattern of brain activity during bladder filling and voiding. There appears to be a greater reliance on primitive centers (cerebellum, midbrain) than in healthy controls during both phases of the micturition cycle. We hypothesize that these findings may reflect loss of connectivity with higher brain centers after a stroke.

Should we be revisiting LUT basic science and clinical measurement of LUT sensation to improve patient care? ICI-RS 2019

AIMS

This article reviews current knowledge of the underpinning mechanisms of how the bladder senses fullness locally and also revisits clinical measurements of lower urinary tract sensation. The former represents cellular sensing during bladder filling whereas the latter describes the sensations leading to conscious perception of bladder fullness.

METHODS

The topic was discussed in a "think tank" session at the 2019 International Consultation on Incontinence-Research Symposium in Bristol, UK; summarized in the present review.

RESULTS

Recent advances in the basic science of bladder sensing relating to (a) the bladder wall-urothelial cells, sensory nerves, interstitial cells, and smooth muscle cells and (b) putative chemo/mechanosensors in the urethra-paraneurons or "brush cells" are discussed. Validated clinical measurement of lower urinary tract sensation is reviewed in the context of how this could be better harnessed for patient benefit. We discuss the potential of app/tablet/mobile technology based on triggers and distractors to override aberrant local sensing/higher sensation and how these technologies could be utilized in treatment.

CONCLUSIONS

We conclude that a better understanding of bladder sensation is essential to inform clinical management of lower urinary tract symptoms.

Brain activation patterns of female multiple sclerosis patients with voiding dysfunction

AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of a strong desire to void on walking speed in individuals with multiple sclerosis and urinary disorders

BACKGROUND

Lower urinary tract symptoms, especially overactive bladder, are frequent and disabling in individuals with multiple sclerosis (IwMS). An association with gait disorders is common, which could aggravate continence difficulties and affect quality of life. The association between the need to void and walking has never been studied in this population.

OBJECTIVE

The primary aim of this study was to assess the effect of a strong desire to void (SDV) on walking speed in IwMS and lower urinary tract symptoms. The secondary aim was to identify clinical or urodynamic factors associated with walking speed impairment at SDV in this population.

METHODS

We included IwMS with urinary disorders and Expanded Disability Status Scale score<7 in this observational study. Individuals underwent 3 10-m walk tests (10MWT) and one Timed Up and Go (TUG) test at SDV and at post-void (PV).

RESULTS

Among the 72 IwMS included (mean [SD] age 50.6 [11.6] years; 46 [64%] females), the mean (SD) speed for 10MWT was 1.00 (0.31) m.s^-1 at SDV and 1.07 (0.30) m.s^-1 at PV (P<0.0001). Time for TUG was also increased when individuals felt SDV: mean 11.53 (4.6) sec at SDV versus 10.77 (3.8) sec at PV (P=0.004). No predictors of greater impairment of walking speed at SDV were identified.

CONCLUSION

This study suggests a clinical impact of bladder sensation on walking speed in IwMS and urinary disorders. None of the individual characteristics could predict greater decrease in gait velocity at SDV.

Association between urinary symptom severity and white matter plaque distribution in women with multiple sclerosis

AIMS

Multiple sclerosis (MS) is characterized by demyelinated white matter plaque throughout the central nervous system. Plaque involvement in regions that regulate micturition may be associated with urinary symptom severity in patients with MS. The aim of this prospective study is to investigate the relationship between cerebral plaque volume (PV), location, and urinary symptoms in women with MS.

METHODS

We conducted a case-control pilot study of women with MS undergoing routine yearly brain MRI. Women were administered the American Urologic Association-Symptom Index (AUA-SI) and divided into two groups: severe urinary symptoms (AUA-SI ≥20) and mild symptoms (AUA-SI ≤7). PV and location in the brain were determined using a validated automated white matter lesion segmentation algorithm.

RESULTS

This study of 36 women found that the median total PV did not differ between groups. Women with severe urinary symptoms had larger median PV in the left frontal lobe (LFL) and right limbic lobe (RLL) compared with women with mild urinary symptoms. Within the RLL, women with severe symptoms had a larger median PV in the right cingulate gyrus (RCG). There was a moderate correlation between LFL lesion volume and RLL lesion volume with the AUA emptying subscore; however, these regions did not correlate with the storage subscore.

CONCLUSIONS

This preliminary study found urinary symptom severity in women with MS is associated with PV in the RCG and LFL, and not total cerebral PV. These findings may explain why disease burden alone is not a predictor of severity or type of voiding dysfunction in patients with MS.

Higher neural contribution underlying persistent lower urinary tract symptoms in men with Benign Prostatic Hyperplasia undergoing bladder outlet procedures

Introduction and Background

Benign Prostatic Hyperplasia (BPH) affects the micturition cycle. Lower urinary tract symptoms (LUTS) refers to storage symptoms such as urinary frequency, urgency, urge urinary incontinence and nocturia. Surgical options for bladder outlet obstruction (BOO) are currently offered for symptomatic improvement. However, 30% of patients report persistent LUTS after BOO procedures. Neuroplasticity induced by BPH and BOO can be contributory in these men, having different brain activation patterns during the micturition cycle. Our multimodal functional Magnetic Resonance Imaging (fMRI) study will identify for the first time, structural and functional brain contributions to LUTS in men with BPH and BOO at baseline and following BOO procedures. We hypothesize that men with symptomatic BPH with persistent LUTS following BOO procedures have a distinct brain activation pattern in regions of interest (ROIs) of the micturition cycle.

Methods

Male patients older than 45 years of age undergoing BOO procedures will be enrolled and categorized in two groups. Group 1: patients with BPH with significant improvement in storage symptoms after BOO procedures. Group 2: patients with BPH with persistent storage symptoms after BOO procedures. Our control group are male patients without LUTS undergoing radical prostatectomy. Patients will complete subjective questionnaires and post void residual at clinic visits. BOLD signals at full urge will be measured at baseline and following BOO procedures. All patients will undergo fMRI studies at baseline and at 6 months. Clinical data will be correlated to BOLD signal changes as well as to structural changes in white matter tracts.

Ethics and dissemination

After IRB approval, patients will be recruited and properly consented before enrolling to this study. Results of neural contribution to lower urinary tract symptoms will be presented at national and international meetings and will be published in scholarly journals.

Voxel-wise lesion mapping of self-reported urinary incontinence in multiple sclerosis

AIMS

Besides spinal lesions, urinary incontinence may be attributed to particular cerebral lesion sites in multiple sclerosis (MS) patients. We intended to determine the contribution of suprapontine lesions to urinary incontinence in MS using a voxel-wise lesion analysis.

METHODS

In this retrospective study, we sought MS patients with documented urinary incontinence in a local database. We established a control group of MS-patients without documented urinary incontinence matched for gender, age, and disease severity. Patients with urinary incontinence due to local diseases of the urinary tract were excluded. The MS lesions were analyzed on T2-weighted magnetic resonance imaging scans (1.5 or 3T). After manual delineation and transformation into stereotaxic space, we determined the lesion overlap and compared the presence or absence of urinary incontinence voxel-wise between patients with and without lesions in a given voxel performing the Liebermeister test with 4000 permutations.

RESULTS

A total of 56 patients with urinary incontinence and MS fulfilled the criteria and were included. The analysis yielded associations between urinary incontinence and MS in the frontal white matter, temporo-occipital, and parahippocampal regions.

CONCLUSIONS

Our voxel-wise analysis indicated associations between self-reported urinary incontinence and lesions in the left frontal white matter and right parahippocampal region. Thus, our data suggest that dysfunction of supraspinal bladder control due to cerebral lesions may contribute to the pathophysiology of urinary incontinence in MS.

Data-Driven Machine-Learning Quantifies Differences in the Voiding Initiation Network in Neurogenic Voiding Dysfunction in Women With Multiple Sclerosis

PURPOSE

To quantify the relative importance of brain regions responsible for reduced functional connectivity (FC) in their Voiding Initiation Network in female multiple sclerosis (MS) patients with neurogenic lower urinary tract dysfunction (NLUTD) and voiding dysfunction (VD). A data-driven machine-learning approach is utilized for quantification.

METHODS

Twenty-seven ambulatory female patients with MS and NLUTD (group 1: voiders, n=15 and group 2: VD, n=12) participated in a functional magnetic resonance imaging (fMRI) voiding study. Brain activity was recorded by fMRI with simultaneous urodynamic testing. The Voiding Initiation Network was identified from averaged fMRI activation maps. Four machine-learning algorithms were employed to optimize the area under curve (AUC) of the receiver-operating characteristic curve. The optimal model was used to identify the relative importance of relevant brain regions.

RESULTS

The Voiding Initiation Network exhibited stronger FC for voiders in frontal regions and stronger disassociation in cerebellar regions. Highest AUC values were obtained with 'random forests' (0.86) and 'partial least squares' algorithms (0.89). While brain regions with highest relative importance (>75%) included superior, middle, inferior frontal and cingulate regions, relative importance was larger than 60% for 186 of the 227 brain regions of the Voiding Initiation Network, indicating a global effect.

CONCLUSION

Voiders and VD patients showed distinctly different FC in their Voiding Initiation Network. Machine-learning is able to identify brain centers contributing to these observed differences. Knowledge of these centers and their connectivity may allow phenotyping patients to centrally focused treatments such as cortical modulation.

Functional MRI in patients with detrusor sphincter dyssynergia: Is the neural circuit affected?

AIMS

In recent years, the human brain-bladder control network has been visualized in different functional magnetic resonance imaging (fMRI) studies. The role of the brainstem and suprapontine regions has been elucidated. Especially the pontine region and the periaqueductal gray, as the central structures of the micturition circuit, were demonstrated. Detrusor sphincter dyssynergia (DSD) is a common problem in patients with neurological diseases. Residual urine and consecutive urinary tract infections with the risk of kidney damage remain a problem. In the present study, we used fMRI of the brain to compare the activation sites of patients with DSD with those of our previously published healthy controls with special emphasis on the brainstem region.

METHODS

fMRI was performed in 11 patients with DSD who had an urge to void due to a filled bladder. In a nonvoiding model, they were instructed to contract or to relax the pelvic floor muscles repetitively.

RESULTS

In patients with DSD, we could reproduce the activation sites found in healthy subjects, showing the regions in the brainstem as well as the other micturition-related areas. The activation of the pontine region was more rostral/dorsal compared with the healthy volunteers.

CONCLUSION

Interestingly, we detected the well-known activation in the pontine region in the patients in the dorsal/rostral part compared with the more ventral activation in the healthy volunteers, suggesting that the L-region of the pontine micturition center is more prominent in cases of DSD.

New Diagnostics for Male Lower Urinary Tract Symptoms

PURPOSE OF REVIEW

Lower urinary tract symptoms (LUTS) is a common constellation of symptoms that affect the aging male population with an astonishing prevalence. New technology and new uses of established technology are being used to help further evaluate LUTS in the male population and help guide treatment options. This review focuses on the developments and future directions in diagnostic modalities for evaluation of male LUTS, focusing on evaluation of both the filling and voiding phases of micturition.

RECENT FINDINGS

New techniques in evaluating the voiding phase include penile cuff test, external pressure sensing condom catheter, ultrasound measurement of detrusor wall thickness, ultrasound measurement of intravesical prostatic protrusion, doppler ultrasound and NIRS technology. Evaluation of the filling phase is still undergoing much development and requires additional validation studies. The techniques undergoing evaluation include sensation meters during UDS, assessing bladder micromotion and wall rhythm, assessing detrusor wall biomechanics, ultrasound measurement of detrusor wall thickness, pelvic doppler ultrasound, as well as functional brain imaging including fNIRS and fMRI.

SUMMARY

The development of novel, non-invasive, diagnostic tools have the potential for better evaluation of LUTS with earlier and enhanced treatments. This will likely improve the quality of life for men with LUTS.

Workflow for Visualization of Neuroimaging Data with an Augmented Reality Device

Commercial availability of three-dimensional (3D) augmented reality (AR) devices has increased interest in using this novel technology for visualizing neuroimaging data. Here, a technical workflow and algorithm for importing 3D surface-based segmentations derived from magnetic resonance imaging data into a head-mounted AR device is presented and illustrated on selected examples: the pial cortical surface of the human brain, fMRI BOLD maps, reconstructed white matter tracts, and a brain network of functional connectivity.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Functional brain imaging in voiding dysfunction

PURPOSE OF REVIEW

Voiding dysfunction (VD) is morbid, costly, and leads to urinary tract infections, stones, sepsis, and permanent renal failure. Evaluation and diagnosis of VD in non-obstructed patients can be challenging. Potential diagnostic and therapeutic options beyond the bladder, such as brain centers involved in voiding have been proposed as promising targets. This review focuses on current and future applications of functional neuroimaging in human in voiding and in patients with VD.

RECENT FINDINGS

The current understanding of brain centers, and their roles in initiating, maintaining and/or modulating voiding, is rudimentary in humans and in patients with VD. With the advent and advancement in functional neuroimaging we are gaining more insight into specific brain regions involved in the voiding phase of micturition. In healthy individuals, right dorsomedial pontine tegmentum, periaqueductal grey, hypothalamus, and the inferior, medial and superior frontal gyrus have been identified as regions of interest in voiding.

SUMMARY

Functional neuroimaging could suggest new diagnostic methods and provides crucial steps towards therapeutic options for the morbid and intractable VD condition, in patients with neurogenic (e.g. MS or Strokes) or non-neurogenic VD (e.g. underactive bladder or Fowler's syndrome).

Similarity of functional connectivity patterns in patients with multiple sclerosis who void spontaneously versus patients with voiding dysfunction

AIM

To investigate if Multiple Sclerosis (MS) lesion characteristics affect functional brain connectivity (FC) during bladder voiding.

METHODS

Twenty-seven ambulatory female patients with MS completed our functional magnetic resonance imaging (fMRI)/urodynamic testing (UDS) platform. Individual fMRI activation maps were generated at initiation of voiding. FC patterns of these regions were calculated and compared. Similarity of the FC pattern from one patient relative to all others was expressed by a parameter FC_sim. A statistical analysis was performed to reveal the relationship of the existence of an enhancing brain lesion, the size of the largest lesion and the ability to void spontaneously to this FC similarity measure.

RESULTS

FC_sim values were significantly lower for patients with an enhancing MS lesion (11.7 ± 3.1 vs 5.3 ± 2.1 P < 0.001). Lesion size smaller than 20 mm inversely correlated significantly with FC_sim (R = -0.43, P = 0.05). Patients with the ability to void spontaneously had a higher FC_sim value (12.0 ± 2.8 vs 9.3 ± 4.4 s, P = 0.08). Patients that exhibited a decrease of compliance also showed a significantly lower FC_sim value (11.3 ± 3.5 vs 4.7 ± 0.7, P < 1e-5).

CONCLUSION

FC connectivity analysis derived from an fMRI task-based study including repetitive voiding cycles is able to quantify the heterogeneity of connectivity patterns in the brain of MS patients. FC similarity decreased with maximum lesion size or the presence of enhancing lesions affecting the ability to void spontaneously.

Protocol for a prospective observational study of cortical lower urinary tract control changes following intradetrusor injection of botulinum toxin-A in patients with multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a severe debilitating disease that affects patients' quality of life. Up to 90% of patients with MS will develop lower urinary tract dysfunction within the first 18 years of the disease. If oral pharmacotherapy with anticholinergics, behavioural modifications and pelvic floor physical therapy are unsuccessful, intradetrusor injection of botulinum toxin-A (OnaBotA; Botox Allergan, Dublin, Ireland) is a highly effective option for these patients. The local effects of OnaBotA are well understood, but not much is known of its afferent/sensory effects while treating the end organ. Our study will use functional MRI (fMRI) and task-related blood oxygen level-dependent signals to evaluate patients with MS and neurogenic detrusor overactivity (NDO) prior to, and after, intradetrusor injection of OnaBotA with simultaneous urodynamic evaluation. Urinary concentration of brain-derived neurotrophic factor and nerve growth factor will also be collected since it has been shown that patients with an overactive bladder have higher concentrations of these neuropeptides.

METHODS AND ANALYSIS

Female patients with MS and lower urinary tract symptoms who previously have undergone urodynamic screening and are refractory to conservative and oral pharmacotherapy management for NDO and are interested in OnaBotA intradetrusor injection will be invited to participate in the study. An fMRI will be performed preintradetrusor injection and postintradetrusor injection of OnaBotA with simultaneous MRI compatible with material urodynamics. Images will be collected and analysed accordingly.

ETHICS AND DISSEMINATION

All of the patients are properly consented before enrolling in this study that has been previously approved by the Institutional Review Board. Results of neural connectivity activation will be presented at national and international meetings and published in scholarly journals.

Functional cortical changes in relapsing-remitting multiple sclerosis at amplitude configuration: a resting-state fMRI study

OBJECTIVE

The aim of this study was to explore the amplitude of spontaneous brain activity fluctuations in patients with relapsing-remitting multiple sclerosis (RRMS) using the amplitude of low-frequency fluctuation (ALFF) method.

METHODS

ALFF and SPM8 were utilized to assess alterations in regional spontaneous brain activities in patients with RRMS in comparison with healthy controls (HCs). The beta values of altered brain regions between patients with RRMS and HCs were extracted, and a receiver operating characteristic (ROC) curve was generated to calculate the sensitivities and specificities of these different brain areas for distinguishing patients with RRMS from HCs. Pearson correlation analyses were applied to assess the relationships between the beta values of altered brain regions and disease duration and Expanded Disability Status Scale (EDSS) score.

PATIENTS AND PARTICIPANTS

A total of 18 patients with RRMS (13 females; five males) and 18 sex-, age-, and education-matched HCs (14 females; four males) were recruited for this study.

MEASUREMENTS AND RESULTS

Compared with HCs, patients with RRMS showed higher ALFF responses in the right fusiform gyrus (Brodmann area [BA] 37) and lower ALFF responses in the bilateral anterior cingulate cortices (BA 24 and 32), bilateral heads of the caudate nuclei, and bilateral brainstem. The ROC analysis revealed that the beta values of these abnormal brain areas showed high degrees of sensitivity and specificity for distinguishing patients with RRMS from HCs. The EDSS score showed a significant negative Pearson correlation with the beta value of the caudate head (r=-0.474, P=0.047).

CONCLUSION

RRMS is associated with disturbances in spontaneous regional brain activity in specific areas, and these specific abnormalities may provide important information about the neural mechanisms underlying behavioral impairment in RRMS.