What is the utility of urodynamics, including ambulatory, and 24 h monitoring, in predicting upper urinary tract damage in neuro-urological patients and other lower urinary tract dysfunction? ICI-RS 2017

Cuprizone-mediated demyelination reversibly degrades voiding behavior in mice while sparing brainstem reflex

Multiple sclerosis (MS) is a chronic, progressively debilitating demyelinating disease of the central nervous system (CNS). Nearly 80% of MS patients experience lower urinary tract dysfunction early in their diagnosis. This significantly affects the quality of life, and in latter stages of disease is a leading cause of hospitalization. Previously, animal models have shown that inflammatory demyelination in the CNS causes profound bladder dysfunction, but the confounding influence of systemic inflammation limits the potential interpretation of the contribution of CNS demyelination to bladder dysfunction. Since the micturition circuit has myelinated neuronal connections in the cortex, brainstem, and spinal cord, we examined alterations in bladder function in the cuprizone model characterized by demyelinating lesions in the cortex and corpus callosum that are independent of T-cell-mediated autoimmunity. Herein, we report that a 4-week dietary cuprizone treatment in C57Bl/6J mice induced alterations in voiding behavior with increased micturition frequency and reduced volume voided, similar to human MS bladder dysfunction. Subsequently, recovery from cuprizone treatment restored normal bladder function. Demyelination and remyelination were confirmed by Luxol Fast Blue staining of the corpus callosum. Additionally, we also determined that an 8-week cuprizone treatment, resulting in chronic demyelination lacking spontaneous remyelination potential, is associated with an exacerbated voiding phenotype. Interestingly, while cuprizone-induced CNS demyelination severely affected conscious (cortical) urinary behavior, the brainstem and spinal cord reflex remained unchanged, as confirmed by urethane-anesthetized cystometry. This is the first study to show that cortical demyelination independent of inflammation can negatively impact urinary function.

Clinical utility of the maximum area of detrusor tracing measurement in the urodynamic studies in pediatric population diagnosed with neuropathic bladder: A pilot study

INTRODUCTION

Neuropathic bladder (NB) is a lower urinary tract dysfunction (LUTD) that may lead to kidney failure. Urodynamic study is the gold standard for its diagnosis and follow-up. A classic prognostic parameter to predict the risk of upper urinary tract damage (UUTD) is the detrusor leak point pressure (DLPP) ≥  40 cmH2O, although this factor alone may lack prognostic value. The area under the curve (AUC) of the detrusor pressure tracing has been recently described as a prognostic factor.

AIM

To analyze the clinical utility of the AUC of the detrusor pressure tracing in the pediatric population (<15 years).

METHODS

Retrospective study of urodynamic recordings in pediatric population with NB from 2011 to 2020. The following variables were evaluated: detrusor leak point pressure ≥ 40 cmH2O, voiding dysfunction, bladder compliance and overactivity. The sample is classified according to clinical-radiological findings at the time of the UD. AUC is calculated using Newton-Cotes rules (trapezium, Simpson's rule) and its indexes are calculated according to bladder capacity (TI: Trapezium Index, SI: Simpson Index). Statistical significance: P < .05.

RESULTS

Fifty-five recordings are analyzed. Unfavorable clinical condition was identified in 41.8% (n = 23) patients. Voiding dysfunction, low compliance and both indexes were associated with an unfavorable clinical condition (P < .05). ROC analysis showed the following AUC for the new indexes: TI (0.736, P = 0.0006), SI (0.755, P = .0001) with a cut-off value of 10,69 and 8 cmH2O·s/cc, respectively. We did not find differences in the diagnostic performance between them (P > .05).

CONCLUSIONS

The analyzed indexes are useful in the diagnosis of patients with NB and unfavorable clinical condition.

Work-up for the neurourological patient

A targeted history and physical examination are the mainstays for basic evaluation of neurourological patients. Urodynamics investigations are of paramount importance in providing information about the pressure situation in the lower urinary tract (LUT). Pressures are crucial not only for LUT but also for upper urinary tract function. Regular ultrasound assessment is advisable but cannot replace invasive urodynamics.

Advances in Ambulatory Urodynamics

PURPOSE OF REVIEW

This manuscript reviews recent technological advances in ambulatory urodynamics.

RECENT FINDINGS

Ambulatory urodynamics is currently recommended by the International Continence Society as a second-line diagnostic tool in patients with nondiagnostic traditional urodynamics. Novel techniques involving telemetric monitoring are in development, which utilize catheter-free wireless systems to address several recognized shortcomings of inoffice urodynamic studies. Current research in catheter-free bladder pressure measurements involves either an intravesical, intradetrusor, or transdetrusor approach. Real-time bladder volume estimation may be performed using ultrasonography, near-infrared spectroscopy, or bladder volume conductance measurement. Ambulatory urodynamics can measure bladder function in the "real world" setting, capturing physiological bladder filling and emptying and allowing patients to reproduce the activities that may trigger their symptoms. Telemetric devices being developed represent further advances in this field and focus upon improving diagnostic capabilities, evaluating patient response to treatment, and facilitating closed-loop bladder control with neuroprosthetic integration.

Ambulatory urodynamic monitoring: state of the art and future directions

Urodynamic studies are a key component of the clinical evaluation of lower urinary tract dysfunction and include filling cystometry, pressure-flow studies, uroflowmetry, urethral function tests and electromyography. However, pitfalls of traditional urodynamics include physical and emotional discomfort, artificial test conditions with catheters and rapid retrograde filling of the bladder, which result in variable diagnostic accuracy. Ambulatory urodynamic monitoring (AUM) uses physiological anterograde filling and, therefore, offers a longer and more physiologically relevant evaluation. However, AUM methods rely on traditional catheters and pressure transducers and do not measure volume continuously, which is required to provide context for pressure changes. Novel telemetric AUM (TAUM) methods that use wireless, catheter-free, battery-powered devices to monitor bladder pressure and volume while patients carry out their daily activities are currently being investigated. TAUM devices under current development are innovating in the areas of remote monitoring, rechargeable energy sources, device deployment and retrieval and materials engineering to provide increased diagnostic accuracy and improved comfort for patients with incontinence or voiding dysfunction. These devices hold promise for improving the diagnosis and management of patients with lower urinary tract disorders.