Controversy over the pharmacological treatments of storage symptoms in spinal cord injury patients: a literature overview

Transcutaneous neuromodulation versus oxybutynin for neurogenic detrusor overactivity in persons with spinal cord injury: A randomized, investigator blinded, parallel group, non-inferiority controlled trial

STUDY DESIGN

This study is a randomized, investigator-blinded, controlled trial with a non-inferiority design.

OBJECTIVE

To investigate the effectiveness of neuromodulation by transcutaneous electrical stimulation of the somatic afferent nerves of the foot in neurogenic detrusor overactivity (NDO) in persons with spinal cord injury (SCI) and compare its effectiveness with oral oxybutynin.

SETTING

The study was conducted in a rehabilitation in-patient ward of a tertiary care hospital.

METHODS

Twenty-nine persons with SCI with NDO, either sex, aged 18 years and above were randomized into two groups, one group receiving oral oxybutynin (5 mg thrice a day for two weeks) and the other transcutaneous electrical stimulation (5 Hz, 200 µs pulse, biphasic, amplitude up to 60 mA, 30 min/day for two weeks). Bladder capacity was evaluated by clinical bladder evaluation (i.e. bladder capacity measured by adding leak volume, voiding volume if any, and post-void residue using a catheter) and cystometric bladder capacity by one-channel cystometry. Maximum cystometric pressure was evaluated by one-channel water cystometry. Data were analyzed with Fisher's Exact, t-test, and Wilcoxon rank sum tests.

RESULTS

Bladder capacity improved significantly in the oxybutynin and neuromodulation groups as measured by one-channel water cystometry (136 ml vs. 120.57 ml) and clinical evaluation (138.93 ml vs. 112 ml). The increase in the neuromodulation group achieved the pre-decided non-inferiority margin of 30 ml over the oxybutynin group when measured by one-channel water cystometry but not by clinical evaluation. Maximum cystometric pressure did not significantly improve in either group when compared with the baseline.

CONCLUSION

Transcutaneous neuromodulation and oxybutynin effectively increased bladder capacity in persons with SCI with NDO. Neuromodulation by once-a-day transcutaneous electrical stimulation was non-inferior to thrice-a-day oxybutynin when evaluated by one-channel water cystometry.Trial registration: Clinical Trials Registry India identifier: CTRI/2018/05/013735.

Transcutaneous Electrical Stimulation for Neurogenic Bladder Dysfunction Following Spinal Cord Injury: Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

To assess the efficacy of transcutaneous electrical nerve stimulation (TENS) for neurogenic bladder dysfunction secondary to spinal cord injury (SCI).

MATERIALS AND METHODS

A systematic search of MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane libraries up to February 2021 was performed using PRISMA methodology. All randomized controlled trials (RCTs) that studied TENS for neurogenic bladder in a SCI population were included. The primary outcomes of interest were maximum cystometric capacity (MCC) and maximum detrusor pressure (Pdet). Meta-analysis was conducted with RevMan v5.3.

RESULTS

Six RCTs involving 353 participants were included. Meta-analysis showed that TENS significantly increased MCC (standardized mean difference 1.11, 95% confidence interval [CI] 0.08-2.14, p = 0.03, I²  = 54%) in acute SCI. No benefits were seen for maximum Pdet. TENS was associated with no major adverse events.

CONCLUSIONS

TENS may be an effective, safe intervention for neurogenic bladder dysfunction following SCI. Further studies are essential to confirm these results and more work is required to determine optimal stimulation parameters and duration of the treatment.

How to treat neurogenic bladder and sexual dysfunction after spinal cord lesion

Neurogenic bladder and sexual dysfunction after spinal cord lesions are highly prevalent. The treatment algorithm for neurogenic bladder is well described. Clean intermittent self-catheterisation associated with treatment of neurogenic detrusor overactivity is the gold standard. Goals of treatment are twofold: i) control risk factors to avoid upper urinary tract complications, and ii) improve quality of life by treating incontinence when feasible. Lower urinary tract dysfunction is still a major cause of complications and hospitalisation. Sexual dysfunction must be addressed and treated and is at the top of patient expectations one year after injury.

Feasibility of Self-administered Neuromodulation for Neurogenic Bladder in Spinal Cord Injury

Purpose

To determine if self-administered transcutaneous tibial nerve stimulation (TTNS) is a feasible treatment option for neurogenic bladder among people with spinal cord injury (SCI) who utilize intermittent catheterization for bladder management.

Methods

Four-week observational trial in chronic SCI subjects performing intermittent catheterization with incontinence episodes using TTNS at home daily for 30 minutes. Those using anticholinergic bladder medications were given a weaning schedule to begin at week 2. Primary outcomes were compliance and satisfaction. Secondary outcomes included change in bladder medications, efficacy based on bladder diary, adverse events, and incontinence quality of life (I-QoL) survey.

Results

All 16 subjects who started the study completed the 4-week trial rating TTNS with high satisfaction and easy to use, without discomfort. Twelve of 14 patients (86%) using anticholinergic bladder medications reduced their dosage and maintained similar frequency and volumes of bladder catheterization and incontinence episodes. Bladder medication reduced by approximately 3.2 mg weekly (95% confidence interval, -5.9 to -0.4) and anticholinergic side effects of dry mouth and drowsiness decreased more than 1 level of severity from baseline (P=0.027, P=0.015, respectively). At 4 weeks, total I-QoL score improved by an average of 3.2 points compared to baseline in all domains.

Conclusions

This pilot trial suggests TTNS is feasible to be performed at home in people with chronic SCI. Participants were able to reduce anticholinergic medication dosage and anticholinergic side effects while maintaining continence, subsequently improving QoL scores. These results advocate for further randomized, controlled trials with longer duration and urodynamic evaluation to assess long-term efficacy.

Long-Term Efficacy of Mirabegron Add-On Therapy to Antimuscarinic Agents in Patients With Spinal Cord Injury

Objective

To evaluate the long-term efficacy of mirabegron add-on therapy in patients with spinal cord injury (SCI) based on an urodynamic study.

Methods

This retrospective study involved a chart audit of individuals with SCI who underwent two consecutive urodynamic studies between April 1, 2015 and April 1, 2018. After adding 50 mg of mirabegron once a day to the pre-existing antimuscarinic therapy for a period of, at least 6 months, the following variables were analyzed: change in cystometric capacity, change in bladder compliance, change in maximal detrusor pressure, change in reflex volume, and presence of significant leakage during filling cystometry.

Results

A total of 31 participants with a mean age of 41±15 years were included in the analysis. A significant increase in cystometric capacity (mean, 362 to 424 mL; p=0.03), reflex volume (mean, 251 to 329 mL; p=0.02), and bladder compliance (median, 12 to 18 mL/cmH₂O; p=0.04) was observed. The presence of leakage during filling cystometry was significantly reduced (29% to 10%; p=0.03). Likewise, a non-significant decrease in the change in maximal detrusor pressure was observed (mean, 31 to 27 cmH₂O; p=0.39).

Conclusion

Adding mirabegron to conventional antimuscarinics further improved urodynamic parameters in patients with chronic SCI, and sustained efficacy was observed in long-term use.

Extraoral Taste Receptor Discovery: New Light on Ayurvedic Pharmacology

More and more research studies are revealing unexpectedly important roles of taste for health and pathogenesis of various diseases. Only recently it has been shown that taste receptors have many extraoral locations (e.g., stomach, intestines, liver, pancreas, respiratory system, heart, brain, kidney, urinary bladder, pancreas, adipose tissue, testis, and ovary), being part of a large diffuse chemosensory system. The functional implications of these taste receptors widely dispersed in various organs or tissues shed a new light on several concepts used in ayurvedic pharmacology (dravyaguna vijnana), such as taste (rasa), postdigestive effect (vipaka), qualities (guna), and energetic nature (virya). This review summarizes the significance of extraoral taste receptors and transient receptor potential (TRP) channels for ayurvedic pharmacology, as well as the biological activities of various types of phytochemical tastants from an ayurvedic perspective. The relative importance of taste (rasa), postdigestive effect (vipaka), and energetic nature (virya) as ethnopharmacological descriptors within Ayurveda boundaries will also be discussed.

Efficacy and Adverse Events Associated With Use of OnabotulinumtoxinA for Treatment of Neurogenic Detrusor Overactivity: A Meta-Analysis

PURPOSE

OnabotulinumtoxinA is used widely for the treatment of neurogenic detrusor overactivity. We conducted a systematic review and meta-analysis to assess its efficacy and safety for neurogenic detrusor overactivity treatment.

METHODS

A systematic literature review was performed to identify all published randomized double-blind, placebo-controlled trials of onabotulinumtoxinA for neurogenic detrusor overactivity treatment. MEDLINE, Embase, and the CENTRAL were employed. Reference lists of retrieved studies were reviewed carefully.

RESULTS

Six publications involving 871 patients, which compared onabotulinumtoxinA with a placebo were analyzed. Efficacy of onabotulinumtoxinA treatment was shown as a reduction of the mean number of urinary incontinence episodes per day (mean difference, -1.41; 95% confidence interval [CI], -1.70 to -1.12; P<0.00001), maximum cystometric capacity (135.48; 95% CI, 118.22-152.75; P<0.00001), and maximum detrusor pressure (-32.98; 95% CI, -37.33 to -28.62; P<0.00001). Assessment of adverse events revealed that complications due to onabotulinumtoxinA injection were localized primarily to the urinary tract.

CONCLUSIONS

This meta-analysis suggests that onabotulinumtoxinA is an effective treatment for neurogenic detrusor overactivity with localized advent events.

Inosine Improves Neurogenic Detrusor Overactivity following Spinal Cord Injury

Neurogenic detrusor overactivity and the associated loss of bladder control are among the most challenging complications of spinal cord injury (SCI). Anticholinergic agents are the mainstay for medical treatment of detrusor overactivity. However, their use is limited by significant side effects such that a search for new treatments is warranted. Inosine is a naturally occurring purine nucleoside with neuroprotective, neurotrophic and antioxidant effects that is known to improve motor function in preclinical models of SCI. However, its effect on lower urinary tract function has not been determined. The objectives of this study were to determine the effect of systemic administration of inosine on voiding function following SCI and to delineate potential mechanisms of action. Sprague−Dawley rats underwent complete spinal cord transection, or cord compression by application of an aneurysm clip at T8 for 30 sec. Inosine (225 mg/kg) or vehicle was administered daily via intraperitoneal injection either immediately after injury or after a delay of 8 wk. At the end of treatment, voiding behavior was assessed by cystometry. Levels of synaptophysin (SYP), neurofilament 200 (NF200) and TRPV1 in bladder tissues were measured by immunofluorescence imaging. Inosine administration decreased overactivity in both SCI models, with a significant decrease in the frequency of spontaneous non−voiding contractions during filling, compared to vehicle−treated SCI rats (p<0.05), including under conditions of delayed treatment. Immunofluorescence staining demonstrated increased levels of the pan-neuronal marker SYP and the Adelta fiber marker NF200, but decreased staining for the C-fiber marker, TRPV1 in bladder tissues from inosine-treated rats compared to those from vehicle-treated animals, including after delayed treatment. These findings demonstrate that inosine prevents the development of detrusor overactivity and attenuates existing overactivity following SCI, and may achieve its effects through modulation of sensory neurotransmission.

Neurogenic bladder in spinal cord injury patients

Neurogenic bladder dysfunction due to spinal cord injury poses a significant threat to the well-being of patients. Incontinence, renal impairment, urinary tract infection, stones, and poor quality of life are some complications of this condition. The majority of patients will require management to ensure low pressure reservoir function of the bladder, complete emptying, and dryness. Management typically begins with anticholinergic medications and clean intermittent catheterization. Patients who fail this treatment because of inefficacy or intolerability are candidates for a spectrum of more invasive procedures. Endoscopic managements to relieve the bladder outlet resistance include sphincterotomy, botulinum toxin injection, and stent insertion. In contrast, patients with incompetent sphincters are candidates for transobturator tape insertion, sling surgery, or artificial sphincter implantation. Coordinated bladder emptying is possible with neuromodulation in selected patients. Bladder augmentation, usually with an intestinal segment, and urinary diversion are the last resort. Tissue engineering is promising in experimental settings; however, its role in clinical bladder management is still evolving. In this review, we summarize the current literature pertaining to the pathology and management of neurogenic bladder dysfunction in patients with spinal cord injury.

γEpithelial Na(+) Channel (γENaC) and the Acid-Sensing Ion Channel 1 (ASIC1) expression in the urothelium of patients with neurogenic detrusor overactivity

OBJECTIVE

To investigate the expression of two types of cation channels, γEpithelial Na(+) Channel (γENaC) and the Acid-Sensing Ion Channel 1 (ASIC1), in the urothelium of controls and in patients affected by neurogenic detrusor overactivity (NDO). In parallel, urodynamic parameters were collected and correlated to the immunohistochemical results.

PATIENTS SUBJECTS AND METHODS

Four controls and 12 patients with a clinical diagnosis of NDO and suprasacral spinal cord lesion underwent urodynamic measurements and cystoscopy. Cold-cup biopsies were frozen and processed for immunohistochemistry and Western Blot. Spearman's correlation coefficient between morphological and urodynamic data was applied. One-way anova followed by Newman-Keuls multiple comparison post hoc test was applied for Western Blot results.

RESULTS

In the controls, γENaC and ASIC1 were expressed in the urothelium with differences in their cell distribution and intensity. In patients with NDO, both markers showed consistent changes either in cell distribution and labelling intensity compared with the controls. A significant correlation between a higher intensity of γENaC expression in the urothelium of patients with NDO and lower values of bladder compliance was detected.

CONCLUSIONS

The present findings show important changes in the expression of γENaC and ASIC1 in NDO human urothelium. Notably, while the changes in γENaC might impair the mechanosensory function of the urothelium, the increase of ASIC1 might represent an attempt to compensate for the excess in local sensitivity.

The possible role of percutaneous tibial nerve stimulation using adhesive skin surface electrodes in patients with neurogenic detrusor overactivity secondary to spinal cord injury

PURPOSE

To compare the effectiveness of percutaneous tibial nerve stimulation (PTNS) using adhesive skin surface electrodes versus solifenacin succinate (SS) in patients with neurogenic detrusor overactivity (NDO) secondary to spinal cord injury (SCI).

METHODS

A randomized controlled study involving 100 patients with NDO secondary to SCI was conducted. Patients were randomized into two groups. In group A, patients received PTNS using adhesive skin surface electrodes for 4 weeks. In group B, patients underwent SS treatment for 4 weeks. Bladder diaries and incontinence quality of life questionnaire were reviewed before treatment and 2 and 4 weeks after treatment.

RESULTS

Improvement in all bladder diary parameters was statistically significant within each group 2 and 4 weeks after treatment compared to baseline (p < 0.05), but did not reach statistical significance between the PTNS and SS groups (p > 0.05). Compared to SS, PTNS was not associated with any unanticipated adverse events.

CONCLUSIONS

PTNS therapy with adhesive skin surface electrodes is an effective method to treat NDO secondary to SCI. This therapy is not only no difference comparing to SS therapy but also noninvasive and easily managed by patients.

Are oxybutynin and trospium efficacious in the treatment of detrusor overactivity in spinal cord injury patients?

OBJECTIVES

To evaluate the efficacy of anticholinergic agents in the treatment of neurogenic overactive bladder (NOAB) and neurogenic detrusor overactivity (NDO) in spinal cord injury (SCI) patients on clean intermittent catheterisation (CIC).

METHODS

Chronic suprasacral SCI patients on CIC presenting with at least one urinary leakage a day were included. Urodynamics and voiding diaries were performed at baseline and 1 month follow-up. In case of NDO at baseline, an anticholinergic drug was prescribed.

RESULTS

The 231 SCI patients presented with one to five urinary leakages per day (mean 2.1). Urodynamics showed NDO in all patients. A new anticholinergic treatment was started in all, either in monotherapy (134 patients) or in association with the existing anticholinergic drug (oxybutynin+trospium bitherapy, 97 patients). The mean maximum bladder capacity significantly increased from 225 to 441 ml, and the mean involuntary detrusor contractions (IDC) significantly decreased from 67 to 41 cm H2O. Only 75 SCI patients (32%) were fully continent. However, 25 out of these 75 patients showed persistent NDO, with amplitudes of IDC above 40 cm H2O in 12 patients. Incontinence was still found in 156 SCI patients (67%), with an average of 1,2 leakages a day. In 100 patients, amplitudes of IDC remained above 40 cm H2O. There was no statistical difference between patients on anticholinergic monotherapy or bitherapy at follow-up.

CONCLUSION

Anticholinergic treatment is not always satisfactory in terms of control of NDO and rarely allows full continence. Urodynamic follow-up is mandatory in all patients, even in those showing clinical continence.

Effects of solifenacin in patients with neurogenic detrusor overactivity as a result of spinal cord lesion

STUDY DESIGN

Retrospective analysis.

OBJECTIVES

To investigate the urodynamic effects of solifenacin treatment for neurogenic detrusor overactivity (NDO) in patients with spinal cord injury (SCI).

SETTING

Paraplegic center in Switzerland.

METHODS

Retrospective analysis of case histories and urodynamic data of 35 SCI patients receiving solifenacin for treatment of NDO between 2008 and 2012. Patients were categorized as being at risk of renal damage when maximum detrusor pressure was >40 cm H2O or detrusor compliance was <20 ml cm(-1) H2O.

RESULTS

Solifenacin treatment was initiated 7.3 years after SCI. Most patients (63%) had already been taking other antimuscarinic drugs. After 13.1 months (median, interquartile range 6.1-19.5 months), solifenacin treatment had resulted in significant (P<0.03) improvements in bladder capacity (median +30.0 ml), maximum detrusor pressure (median -7.0 cm H2O), reflex volume (median +62.5 ml) and detrusor compliance (median +25.0 ml cm(-1) H2O). Furthermore, fewer patients presented with a risk of renal damage. However, this difference was not significant (P>0.1). The number of patients suffering from incontinence had not changed significantly. Eight and two patients discontinued solifenacin treatment as a result of insufficient efficacy and intolerable adverse events, respectively. One patient had discontinued solifenacin treatment without further explanation.

CONCLUSION

Solifenacin treatment significantly improved bladder capacity, detrusor compliance, reflex volume and maximum detrusor pressure. Solifenacin treatment seems to be an effective oral treatment of NDO after SCI.