Neuromodulation in neurogenic bladder

Functional mapping of the lower urinary tract by epidural electrical stimulation of the spinal cord in decerebrated cat model

Several neurologic diseases including spinal cord injury, Parkinson's disease or multiple sclerosis are accompanied by disturbances of the lower urinary tract functions. Clinical data indicates that chronic spinal cord stimulation can improve not only motor function but also ability to store urine and control micturition. Decoding the spinal mechanisms that regulate the functioning of detrusor (Detr) and external urethral sphincter (EUS) muscles is essential for effective neuromodulation therapy in patients with disturbances of micturition. In the present work we performed a mapping of Detr and EUS activity by applying epidural electrical stimulation (EES) at different levels of the spinal cord in decerebrated cat model. The study was performed in 5 adult male cats, evoked potentials were generated by EES aiming to recruit various spinal pathways responsible for LUT and hindlimbs control. Recruitment of Detr occurred mainly with stimulation of the lower thoracic and upper lumbar spinal cord (T13-L1 spinal segments). Responses in the EUS, in general, occurred with stimulation of all the studied sites of the spinal cord, however, a pronounced specificity was noted for the lower lumbar/upper sacral sections (L7-S1 spinal segments). These features were confirmed by comparing the normalized values of the slope angles used to approximate the recruitment curve data by the linear regression method. Thus, these findings are in accordance with our previous data obtained in rats and could be used for development of novel site-specific neuromodulation therapeutic approaches.

Electroacupuncture Therapy for Urinary Retention in an Elderly Patient

Background

Urinary retention is the inability to urinate voluntarily and difficulty in urinating even when the bladder is full. Acute urinary retention is most common in men aged 60-80. In the past 5 years, 10% of men older than age 70 and almost a third of men in their 80s have experienced acute urinary retention. Risk factors include prostate enlargement, increasing age, African-American race, obesity, diabetes mellitus, high alcohol consumption, and lack of physical activity. Treatment for urinary retention is mainly urethral catheterization, but it can be uncomfortable for a patient in the long term.

Case

A 68-year-old man was unable to urinate voluntarily for 3 months and was diagnosed with urinary retention caused by a hypotonic bladder and was initially given a catheter. The patient then received manual acupuncture therapy in acupoints ST-28, CV-3, CV-4 and CV-6, and electroacupuncture (EA) therapy in acupoints SP-6, SP-9, BL-23, BL-25, BL-31, BL-32, BL-33, and BL34, with a continuous-wave, at a frequency of 2 Hz. Acupuncture therapy was carried out for 12 sessions, twice per week.

Results

After 5 sessions of acupuncture therapy, the patient's urinary retention was resolved. He felt the urge to urinate and was able to urinate voluntarily even after removing the catheter, He also experienced an increase in his quality of life, as shown on an EQ-5D questionnaire with an increased score from 50 to 80.

Conclusions

A combination of manual acupuncture and EA in an elderly patient can be a safe choice to reduce or resolve symptoms of urinary retention.

Prediction of early bladder outcomes after spinal cord injury: The HALT score

AIMS

Neurogenic bladder (NB) is a prevalent and debilitating consequence of spinal cord injury (SCI). Indeed, the accurate prognostication of early bladder outcomes is crucial for patient counseling, rehabilitation goal setting, and personalized intervention planning.

METHODS

A retrospective exploratory analysis was conducted on a cohort of consecutive SCI patients admitted to a rehabilitation facility in China from May 2016 to December 2022. Demographic, clinical, and electrophysiological data were collected within 40 days post-SCI, with bladder outcomes assessed at 3 months following SCI onset.

RESULTS

The present study enrolled 202 SCI patients with a mean age of 40.3 ± 12.3 years. At 3 months post-SCI, 79 participants exhibited complete bladder emptying. Least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analyses identified the H-reflex of the soleus muscle, the American Spinal Injury Association Lower Extremity Motor Score (ASIA-LEMS), and the time from lesion to rehabilitation facility (TLRF) as significant independent predictors for bladder emptying. A scoring system named HALT was developed, yielding a strong discriminatory performance with an area under the receiver operating characteristics curve (aROC) of 0.878 (95% CI: 0.823-0.933). A simplified model utilizing only the H-reflex exhibited excellent discriminatory ability with an aROC of 0.824 (95% CI: 0.766-0.881). Both models demonstrated good calibration via the Hosmer-Lemeshow test and favorable clinical net benefits through decision curve analysis (DCA). In comparison to ASIA-LEMS, both the HALT score and H-reflex showed superior predictive accuracy for bladder outcome. Notably, in individuals with incomplete injuries, the HALT score (aROC = 0.973, 95% CI: 0.940-1.000) and the H-reflex (aROC = 0.888, 95% CI: 0.807-0.970) displayed enhanced performance.

CONCLUSION

Two reliable models, the HALT score and the H-reflex, were developed to predict bladder outcomes as early as 3 months after SCI onset. Importantly, this study provides hitherto undocumented evidence regarding the predictive significance of the soleus H-reflex in relation to bladder outcomes in SCI patients.

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.

Neuromyelitis optica in a young patient presenting with urinary retention: A case report

Neuromyelitis optica (NMO) is a rare autoimmune disorder of the central nervous system that can cause a variety of neurological symptoms, including urinary dysfunction. Here, we present the case of a 21-year-old male patient who was diagnosed with NMO after presenting with urinary retention.

Comparison of the efficacy and safety of sacral root magnetic stimulation with transcutaneous posterior tibial nerve stimulation in the treatment of neurogenic detrusor overactivity: an exploratory randomized controlled trial

Background

Both repetitive sacral root magnetic stimulation (rSMS) and transcutaneous posterior tibial nerve stimulation (TTNS) have demonstrated clinical benefits for lower urinary tract dysfunction. However it still remains unclear that which method is more effective and safer to treat neurogenic detrusor overactivity (NDO).

Methods

From December 2020 to December 2021, 50 patients (31 men and 19 women, aged 47.9±12.4 years) with NDO secondary to suprasacral spinal cord injury (SCI) were enrolled and randomly allocated to the rSMS or TTNS group based on a computer-generated random numbers table. The stimulation was applied continuously 5 times per week for 20 sessions. Urodynamic test was conducted at baseline and the day after the final 20th treatment session. The primary outcome was the individual change (Δ) in maximum cystometric capacity (MCC) from baseline to post-treatment. Secondary outcomes included changes (Δ) for the following parameters: volume at 1st involuntary detrusor contraction (1st IDCV), maximal detrusor pressure (Pdetmax), bladder compliance (BC), postvoid residual (PVR) volume, and bladder voiding efficiency (BVE). Additionally, adverse reactions including pain and skin irritation during stimulation were observed and recorded as safety outcomes.

Results

Finally 47 patients completed the study (23 in rSMS and 24 in TTNS group). A per-protocol (PP) analysis was performed, and Mann-Whitney U test and unpaired t-test were used for statistical analysis. Compared with the efficacy of TTNS, rSMS showed statistically greater ΔMCC [median +43 mL (IQR, 22–62 mL) vs. +20 mL (IQR, 15–25 mL), P=0.001, with a between-group difference of +22 mL (95% CI: +7 to +35 mL)] and ΔBVE [median +10.0% (IQR, 3.8–15.7%) vs. +3.5% (IQR, 0.0–7.8%), P=0.003, with a between-group difference of +5.9% (95% CI: +1.2% to +9.7%)]. No significant differences were found in Δ1st IDCV (P=0.40), ΔPdetmax (P=0.67), ΔBC (P=0.79) and ΔPVR (P=0.92) between the two groups. Meanwhile, patients exhibited high tolerance to both protocols, and no adverse reactions were observed.

Conclusions

RSMS may be more effective to improve urodynamics in the treatment for NDO than TTNS, cause it led to a statistical improvement in bladder capacity and voiding efficiency, without any side effects. RSMS is thus worthy of further clinical promotion.

Trial Registration

Chinese Clinical Trial Registry ChiCTR2100050663.

Home-Based SCONETM Therapy Improves Symptoms of Neurogenic Bladder

A wide range of dysfunction can occur after a stroke including symptoms such as urinary urgency, frequency, and urge incontinence. The Spinal Cord Neuromodulator (SCONE^TM) reactivates and retrains spinal neural networks. The present case study introduces initial evidence that home-based, self-administered SCONE therapy may be a safe and effective method of delivering this neuromodulation modality and may have the ability to minimize clinic visits, which is especially salient in today's public health environment.

Does age alone negatively predict the outcome of sacral neuromodulation? A single-centre retrospective observational study

BACKGROUND

For patients over the age of 70 years, sacral neuromodulation (SNM) is often not considered a potential therapeutic option. We therefore report on our results from performing SNM in elderly patients ≥70 years.

METHODS

Between 01/09 and 12/18, a total of 95 patients with refractory overactive bladder (OAB) or chronic non-obstructive urinary retention underwent SNM testing at our department. In the overall sample, 20 patients were aged 70 years or older (21%, group B), and 75 patients were under 70 years old (79%, group A). The mean follow-up period was 50.2 ± 36.2 months. Pre-, peri- and postoperative parameters were compared between the two groups. Statistical analysis was carried out with SPSS 25.0 (p < 0.05).

RESULTS

The mean patient age was 53 ± 16 (17-76) years. The indications for SNM testing were OAB and retention in 51 and 49% of patients, respectively. A total of 56 patients (59%) [8 patients (40%) in group B, 48 patients (64%) in group A] had more than 50% improvement in the context of the test (stage 1), such that a permanent neuromodulator (stage 2) was implanted. A total of 14 patients, all under 70 years old except for one older female, needed to undergo revision due to defects or infection. Overall, the success rate was 58.3% for OAB and 59.6% for urinary retention. The success rates and complications in our patient group were independent of age and geriatric assessment.

CONCLUSION

SNM can also be successfully implemented in older patients.

Stimulation of the pelvic nerve increases bladder capacity in the PGE2 cat model of overactive bladder

Selective electrical stimulation of the pudendal nerve exhibits promise as a potential therapy for treating overactive bladder (OAB) across species (rats, cats, and humans). More recently, pelvic nerve (PelN) stimulation was demonstrated to improve cystometric bladder capacity in a PGE₂ rat model of OAB. However, PelN stimulation in humans or in an animal model that is more closely related to humans has not been explored. Therefore, our objective was to quantify the effects of PGE₂ and PelN stimulation in the cat. Acute cystometry experiments were conducted in 14 α-chloralose-anesthetized adult, neurologically intact female cats. Intravesical PGE₂ decreased bladder capacity, residual volume, threshold contraction pressure, and mean contraction pressure. PelN stimulation reversed the PGE₂-induced decrease in bladder capacity and increased evoked external urethral sphincter electromyographic activity without influencing voiding efficiency. The increases in bladder capacity generated by PelN stimulation were similar in the rat and cat, but the stimulation parameters to achieve this effect differed (threshold amplitude at 10 Hz in the rat vs. twice threshold amplitude at 1 Hz in the cat). These results highlight the potential of PGE₂ as a model of OAB and provide further evidence that PelN stimulation is a promising approach for the treatment of OAB symptoms.

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.

Bladder Neuromodulation in Acute Spinal Cord Injury via Transcutaneous Tibial Nerve Stimulation: Cystometrogram and Autonomic Nervous System Evidence From a Randomized Control Pilot Trial

Aim: Percutaneous tibial nerve stimulation is used to decrease incontinence in chronic neurogenic bladder. We report the findings from a subset of patients in a randomized control trial of transcutaneous tibial nerve stimulation (TTNS) for bladder neuromodulation in acute spinal cord injury (SCI) in whom heart rate variability (HRV) was recorded before and after cystometrogram (CMG). The aim was to correlate autonomic nervous system (ANS) changes associated with the CMG changes after the trial using HRV analyses.

Methods: The study was a double-blinded sham-controlled 2-week trial with consecutive acute SCI patients admitted for inpatient rehabilitation, randomized to TTNS vs. control sham stimulation. Pre- and Post- trial CMG were performed with concurrent 5-min HRV recordings with empty bladder and during filling. Primary outcomes were changes with CMG between/within groups and associations to the HRV findings.

Results: There were 10 subjects in the TTNS group and 6 in the control group. Pre-trial baseline subject characteristics, blood pressures (BPs), and CMG were similar between groups. In both groups, the pre-trial systolic BP increased during filling CMG. After the trial, the control group had significantly increased detrusor pressure and counts of detrusor-sphincter dyssynergia on CMG, not seen in the TTNS group. Also, the control group did not maintain rising BP post-trial, which was observed pre-trial and remained in the TTNS group post-trial. HRV was able to detect a difference in the ANS response to bladder filling between groups. Post-trial HRV was significant for markers of overall increased parasympathetic nervous system activity during filling in the controls, not seen in the TTNS group.

Conclusion: Preliminary evidence suggests that TTNS in acute SCI is able to achieve bladder neuromodulation via modulation of ANS functions.

Clinical Trial Registration:clinicaltrials.gov, NCT02573402.

Detecting Bladder Biomarkers for Closed-Loop Neuromodulation: A Technological Review

Neuromodulation was introduced for patients with poor outcomes from the existing traditional treatment approaches. It is well-established as an alternative, novel treatment option for voiding dysfunction. The current system of neuromodulation uses an open-loop system that only delivers continuous stimulation without considering the patient's state changes. Though the conventional open-loop system has shown positive clinical results, it can cause problems such as decreased efficacy over time due to neural habituation, higher risk of tissue damage, and lower battery life. Therefore, there is a need for a closed-loop system to overcome the disadvantages of existing systems. The closed-loop neuromodulation includes a system to monitor and stimulate micturition reflex pathways from the lower urinary tract, as well as the central nervous system. In this paper, we reviewed the current technological status to measure biomarker for closed-loop neuromodulation systems for voiding dysfunction.

Low-dose onabotulinumtoxinA improves urinary symptoms in noncatheterizing patients with MS

Objective

To evaluate the efficacy and safety of onabotulinumtoxinA 100 U in noncatheterizing patients with multiple sclerosis (MS) with urinary incontinence (UI) due to neurogenic detrusor overactivity (NDO).

Methods

In this randomized, double-blind phase III study, patients received onabotulinumtoxinA 100 U (n = 66) or placebo (n = 78) as intradetrusor injections via cystoscopy. Assessments included changes from baseline in urinary symptoms, urodynamics, and Incontinence–Quality of Life (I-QOL) total score. Adverse events (AEs) were assessed, including initiation of clean intermittent catheterization (CIC) due to urinary retention.

Results

OnabotulinumtoxinA vs placebo significantly reduced UI at week 6 (−3.3 episodes/day vs −1.1 episodes/day, p < 0.001; primary endpoint). Significantly greater proportions of onabotulinumtoxinA-treated patients achieved 100% UI reduction (53.0% vs 10.3%, p < 0.001). Significant improvements in urodynamics (p < 0.01) were observed with onabotulinumtoxinA. Improvements in I-QOL score were significantly greater with onabotulinumtoxinA (40.4 vs 9.9, p < 0.001) and ≈3 times the minimally important difference (+11 points). The most common AE was urinary tract infection (25.8%). CIC rates were 15.2% for onabotulinumtoxinA and 2.6% for placebo.

Conclusion

In noncatheterizing patients with MS, onabotulinumtoxinA 100 U significantly improved UI and quality of life with lower CIC rates than previously reported with onabotulinumtoxinA 200 U.

ClinicalTrials.gov identifier:

NCT01600716.

Classification of evidence

This study provides Class I evidence that compared with placebo, 100 U onabotulinumtoxinA intradetrusor injections significantly reduce UI and improve quality of life in noncatheterizing patients with MS and NDO.

Electrical neuromodulation in the management of lower urinary tract dysfunction: evidence, experience and future prospects

Lower urinary tract dysfunction (LUTD) is common and causes a spectrum of morbidity and decreased quality of life (QoL) for patients. LUTD can range from urinary retention to urge incontinence, and includes a variety of syndromes, with the most common and widely recognized being overactive bladder (OAB). The classic treatments of LUTD and OAB comprise different strategies including behavioral therapies, medications and minimally invasive or invasive surgical procedures. Generally, once patients have tried behavioral modifications and oral medical therapy, and have not experienced adequate relief of their symptoms, the next step is to consider minimally invasive therapies. In the last two decades since FDA approval, sacral nerve stimulation (SNS) has become an accepted intervention, with increasing use and evidence of effectiveness for LUTD, specifically OAB and non-obstructive urinary retention. SNS has shown both objective and subjective improvement in voiding symptoms in several randomized controlled trials (RCTs) when compared to sham or standard medical therapy. The main limitations for more extensive use include relatively high cost, implantation of a device and possibly reoperation secondary to adverse events (AE). Percutaneous tibial nerve stimulation (PTNS) is a less invasive, less direct and less expensive method for neuromodulation, which has also shown effectiveness in several randomized and non-randomized trials, including comparable improvement rates to anticholinergics in OAB management. However, the efficacy of PTNS is only maintained for a short period after the stimulation is delivered. This technique has a much lower rate of AE compared to SNS, but with the inconvenience of weekly visits for stimulation, although implantable devices are on the horizon. In this article we review the mechanism of action, indications, effectiveness and complications related to SNS and PTNS therapy for LUTD.

Increasing bladder capacity by foot stimulation in rats with spinal cord injuries

Background

This study was to explore the possibility that foot stimulation increased bladder capacity(BC) in rats with neurogenic bladder secondary to T10 spinal cord injuries.

Methods

In 20 awake rats (stimulation group) with T10 spinal cord injuries, 5 repeat cystometrograms (CMGs) were recorded. The 1st and 2nd CMGs were performed without stimulation. The 3rd, 4th, and 5th CMGs were done separately with 1 T, 2 T, and 4 T stimulation, respectively, through a pair of pad electrodes on the skin of the hind foot. In the control group of 20 rats, 5 repeat CMGs were recorded without foot stimulation. The threshold (T) was the minimal stimulation intensity to induce an observable toe twitch.

Results

In the stimulation group, foot stimulation with 2 T significantly increased the BC an additional 68.9% ± 20.82% (p < 0.05). Foot stimulation with 4 T increased the BC an additional 120.9% ± 24.82% (p < 0.05). Compared with the control group, BC in the 1st, 2nd, and 3rd (1 T) CMG had no significant difference in the stimulation group, but the 4th (2 T) and 5th (4 T) CMGs were significantly increased (p < 0.05).

Conclusions

Electrical stimulation of the foot was effective in inhibiting reflex bladder activity and increasing bladder capacity in spinal cord injury rats.