Does Tolterodine Extended Release Affect the Bladder Electrical Perception Threshold? A Placebo Controlled, Double-Blind Study With 4 and 8 mg in Healthy Volunteers

Does urinary urgency drive urinary frequency in overactive bladder?

OBJECTIVES

To determine if reduction in urgency in patients with refractory overactive bladder syndrome (rOAB) is correlated with a reduction in voiding frequency and symptom bother.

METHODS

Data from a prospective series of women with rOAB undergoing radiofrequency ablation of the subtrigonal tissue, termed selective bladder denervation (SBD), was analyzed. Main outcome measures included urgency voids, nonurgency voids, and urgency urinary incontinence (UUI) epidsodes from a 3-day voiding diary and quality of life (QoL) measures (Overactive Bladder Questionnaire Short Form [OAB-q SF]).

RESULTS

The dataset comprised 62 completer subjects at 6 months. Compared to baseline, UUI and urgency voids were lower (P < .001), but nonurgency voids were increased (P < .001) and QoL measures were improved (P < .001), but functional bladder capacity did not increase. At baseline and 6 months post treatment, symptom bother was correlated with urgency voids (P < .05) but inversely correlated with nonurgency voids (P < .001). Urgency and nonurgency voids were inversely related at baseline and at 6 months (P < .0001). Following treatment, urgency voids decreased by 41% and nonurgency voids increased by 33%.

CONCLUSIONS

As with other interventions for OAB, SBD resulted in a reduction in OAB symptoms and an improvement in QoL measures. However, the decrease in urgency voids was offset by an increase in nonurgency voids, suggesting that habit or defensive voiding is a significant driver of urinary frequency. It is not certain if this is a unique finding of the SBD effect, but these data do suggest that analyses of outcomes of other OAB interventions are warranted to gain a better understanding of the genesis of OAB symptoms.

Lower urinary tract electrical sensory assessment: A systematic review and meta-analysis

Objectives

To summarize the current literature on lower urinary tract electrical sensory assessment (LUTESA), with regard to current perception thresholds (CPTs) and sensory evoked potentials (SEPs), and to discuss the applied methods in terms of technical aspects, confounding factors, and potential for lower urinary tract (LUT) diagnostics.

Methods

The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) statement. Medline (PubMed), Embase and Scopus were searched on 13 October 2020. Meta‐analyses were performed and methodological qualities of the included studies were defined by assessing risk of bias (RoB) as well as confounding.

Results

After screening 9925 articles, 80 studies (five randomized controlled trials [RCTs] and 75 non‐RCTs) were included, comprising a total of 3732 patients and 692 healthy subjects (HS). Of these studies, 61 investigated CPTs exclusively and 19 reported on SEPs, with or without corresponding CPTs. The recording of LUTCPTs and SEPs was shown to represent a safe and reliable assessment of LUT afferent nerve function in HS and patients. LUTESA demonstrated significant differences in LUT sensitivity between HS and neurological patients, as well as after interventions such as pelvic surgery or drug treatments. Pooled analyses showed that several stimulation variables (e.g. stimulation frequency, location) as well as patient characteristics might affect the main outcome measures of LUTESA (CPTs, SEP latencies, peak‐to‐peak amplitudes, responder rate). RoB and confounding was high in most studies.

Conclusions

Preliminary data show that CPT and SEP recordings are valuable tools to more objectively assess LUT afferent nerve function. LUTESA complements already established diagnostics such as urodynamics, allowing a more comprehensive patient evaluation. The high RoB and confounding rate was related to inconsistency and inaccuracy in reporting rather than the technique itself. LUTESA standardization and well‐designed RCTs are crucial to implement LUTESA as a clinical assessment tool.

Does electrical stimulation in the lower urinary tract increase urine production? A randomised comparative proof-of-concept study in healthy volunteers

Trial design

During electrical stimulation in the lower urinary tract for the purpose of current perception threshold and sensory evoked potential recording, we observed that bladder volume increased rapidly. The aim of this prospective randomised comparative proof-of-concept study was to quantify urine production per time during stimulation of the lower urinary tract using different stimulation frequencies.

Methods

Ninety healthy subjects (18 to 36 years old) were included. Forty females and 50 males were randomly assigned to one of the following study groups: dome, trigone or proximal, membranous (males only) or distal urethra. Starting from 60mL prefilling, stimulation was performed at two separate visits with a 14 French custom-made catheter using randomly applied frequencies of 0.5Hz, 1.1Hz, 1.6Hz (each with 500 stimuli). After each stimulation cycle per frequency, urine production was assessed. Main outcome measures represented urine production during stimulation, daily life and their ratio.

Results

Lower urinary tract electrical stimulation increased urine production per time compared to bladder diary baseline values. Linear mixed model showed that frequency (p<0.001), stimulation order (p = 0.003), intensity (p = 0.042), and gender (p = 0.047) had a significant influence on urine production. Location, visit and age had no significant influence.

Conclusions

Urine production is increased during electrical stimulation with a bigger impact of higher frequencies. This might be relevant for methodological aspects in the assessment of lower urinary tract afferent function and for patients with impaired renal urine output. Inhibition of renal sympathetic nerve activity by vagal afferents may be the underlying mechanism.

Protocol for a prospective, randomized study on neurophysiological assessment of lower urinary tract function in a healthy cohort

Background

Lower urinary tract symptoms are highly prevalent and a large proportion of these symptoms are known to be associated with a dysfunction of the afferent pathways. Diagnostic tools for an objective and reproducible assessment of afferent nerve function of the lower urinary tract are missing. Previous studies showed first feasibility results of sensory evoked potential recordings following electrical stimulation of the lower urinary tract in healthy subjects and patients. Nevertheless, a refinement of the methodology is necessary.

Methods

This study is a prospective, randomized trial conducted at Balgrist University Hospital, Zürich, Switzerland. Ninety healthy subjects (forty females and fifty males) without lower urinary tract symptoms are planned to be included in the study. All subjects will undergo a screening visit (including standardized questionnaires, 3-day bladder diary, urinalysis, medical history taking, vital signs, physical examination, neuro-urological examination) followed by two measurement visits separated by an interval of 3 to 4 weeks. Electrical stimulations (0.5Hz-5Hz, bipolar, square wave, pulse width 1 ms) will be applied using a custom-made transurethral catheter at different locations of the lower urinary tract including bladder dome, trigone, proximal urethra, membranous urethra and distal urethra. Every subject will be randomly stimulated at one specific site of the lower urinary tract. Sensory evoked potentials (SEP) will be recorded using a 64-channel EEG cap. For an SEP segmental work-up we will place additional electrodes on the scalp (Cpz) and above the spine (C2 and L1). Visit two and three will be conducted identically for reliability assessment.

Discussion

The measurement of lower urinary tract SEPs elicited by electrical stimulation at different locations of the lower urinary tract has the potential to serve as a neurophysiological biomarker for lower urinary tract afferent nerve function in patients with lower urinary tract symptoms or disorders. For implementation of such a diagnostic tool into clinical practice, an optimized setup with efficient and reliable measurements and data acquisition is crucial. In addition, normative data from a larger cohort of healthy subjects would provide information on variability, potential confounding factors and cut-off values for investigations in patients with lower urinary tract dysfunction/symptoms.

Trial registration

Clinicaltrials.gov; Identifier: NCT02272309.

Sensory function assessment of the human male lower urinary tract using current perception thresholds

AIMS

To evaluate the feasibility and reliability of current perception threshold (CPT) measurement for sensory assessment of distinct locations in the male lower urinary tract (LUT).

METHODS

Twelve male subjects (>18 years) without LUT symptoms or medical comorbidities were eligible. CPTs were determined twice (interval: 7-20 days) at the bladder dome, trigone and the proximal, membranous, and distal urethra. Square wave electrical stimulation of 3 Hz/0.2 ms and 0.5 Hz/1 ms was applied using a transurethral 8F catheter placed under fluoroscopic control. Bladder volume was kept constant (60 mL) using a second 10F catheter. Repetitive measurements and reliability were assessed by analysis of variance (ANOVA) and intraclass correlation coefficient (ICC).

RESULTS

The ANOVA revealed significant main effects for stimulation site (P = 0.008) and type of stimulation (P < 0.001) with lower CPTs for 0.5 Hz/1 ms compared to 3 Hz/0.2 ms. There was no significant effect for visit number (P = 0.061). CPTs were higher for bladder dome than for proximal (0.5 Hz/1 ms: P = 0.022; 3 Hz/0.2 ms: P = 0.022) and distal urethra (0.5 Hz/1 ms: P = 0.026; 3 Hz/0.2 ms: P = 0.030). Reliability of CPT measurements was excellent to good (ICC = 0.67-0.96) except for the bladder dome (5 Hz/1 ms: ICC = 0.45; 3 Hz/0.2 ms: ICC = 0.20) and distal urethra (3 Hz/0.2 ms: ICC = 0.57).

CONCLUSIONS

CPTs can be reliably detected at different LUT locations. However, alert and compliant subjects are essential. CPTs of LUT may become a complementary assessment method providing information on responsiveness and sensitivity of afferent LUT nerves. This is especially relevant for urethral afferents, which are not covered by standard urodynamic investigations. Neurourol. Urodynam. 36:469-473, 2017. © 2016 Wiley Periodicals, Inc.

Medication effects on periurethral sensation and urethral sphincter activity

AIM

The aim of this study was to characterize urethral neuromuscular function before and 2 weeks after medication therapy.

METHODS

Premenopausal women without lower urinary tract symptoms were randomly allocated to 1 of the 6 medications for 2 weeks (pseudoephedrine ER of 120 mg, imipramine of 25 mg, cyclobenzaprine of 10 mg, tamsulosin of 0.4 mg, solifenacin of 5 mg, or placebo). At baseline and after medication, participants underwent testing: quantitative concentric needle electromyography (CNE) of the urethral sphincter using automated multimotor unit action potential software, current perception threshold (CPT) testing to measure periurethral sensation, and standard urodynamic pressure flow studies (PFS). Nonparametric tests were used to compare pre-post differences.

RESULTS

Fifty-six women had baseline testing, 48 (85.7%) completed follow-up CNE, and 49 (87.5%) completed follow-up CPT and PFS testing. Demographics showed no significant differences among medication groups with respect to age (mean, 34.3; SD, 10.1), body mass index (mean, 31.8; SD, 7.5), parity (median, 1; range, 0-7), or race (14% Caucasian, 80% African American). The PFS parameters were not significantly different within medication groups. No significant pre-post changes in CNE values were noted; however, trends in amplitudes were in a direction consistent with the expected physiologic effect of the medications. With CPT testing, a trend toward increased urethral sensation at the 5-Hz stimulation level was observed after treatment with pseudoephedrine (0.15-0.09 mA at 5 Hz, P = 0.03).

CONCLUSIONS

In women without lower urinary tract symptoms, pseudoephedrine improved urethral sensation but not urethral neuromuscular function on CNE or PFS. Imipramine, cyclobenzaprine, tamsulosin, solifenacin, and placebo did not change urethral sensation or neuromuscular function.

Antimuscarinic effects on current perception threshold: a prospective placebo control study

AIMS

To evaluate the effect of Tolterodine on urethral and bladder afferent nerves in women with detrusor overactivity (DO) in comparison to placebo, by studying the changes in the current perception threshold (CPT).

METHODS

Women with overactive bladder symptoms and idiopathic DO were recruited and randomized in a double-blind manner between placebo and tolterodine extended release. All women underwent CPT testing of the bladder and urethra using a Neurometer constant current stimulator. CPT values were determined at three frequencies, including 2,000 Hz (corresponding to Aβ-fibers), 250 Hz (corresponding to Aδ-fibers), and 5 Hz (corresponding to C fibers) before and 7 days on treatment. CPT values before and on treatment were compared using a Wilcoxon Signed Rank test.

RESULTS

Twenty women (mean age 46 years) were studied. There was no statistical difference between the two groups in terms of age, ethnicity, severity of symptoms and pre-treatment CPT values. Only in the tolterodine group there was a significantly increased CPT value at 5 and 250 Hz upon both urethral and bladder stimulation after 1 week of treatment. When compared with placebo, women taking tolterodine had significantly increased Bladder CPT values at 5 Hz (P-value <0.05). The electrical stimulation with 5 Hz was described as urgency.

CONCLUSIONS

This is a randomized placebo control study evaluating the effect of antimuscarinics on sensory nerve function in women with DO. Our results support the animal studies that antimuscarinics have an effect on sensory function.