Neurophysiological control of urinary bladder storage and voiding-functional changes through development and pathology

Immediate and continued results of parasacral transcutaneous electrical nerve stimulation in paediatric patients with overactive bladders

INTRODUCTION

Among the conditions underlying childhood daytime incontinence the most frequent is overactive bladder (OAB). Parasacral transcutaneous electrical nerve stimulation (parasacral TENS) is a promising therapy for OAB treatment in children; however, there is no standard treatment protocol.

OBJECTIVE

To evaluate the immediate and continued effects of parasacral TENS monotherapy in children with OAB.

STUDY DESIGN

57 children at mean age 10.8 years diagnosed with OAB at a single centre were prospectively enrolled from 2013 to 2018. The inclusion criterion was typical OAB symptoms. The treatment results were evaluated based on objective measurements from bladder diaries, 48 h frequency/volume (48 h F/V) charts, and uroflowmetry. The parasacral TENS treatment lasted for 4 months, twice daily, with 1 h sessions. Results were evaluated at three time points: 2 months of therapy, 4 months (end of active therapy), and 10 months (6 months after cessation of therapy).

RESULTS

After 4 months of parasacral TENS treatment, the number of days with daytime incontinence decreased from 7.23 to 3.94/14 days (p < 0.05), nocturnal enuresis decreased from 6.81 to 3.77/14 days (p < 0.05), and urgency episodes from 7.36 to 3.58 in 14 days (p < 0.05). Treatment effects remained stable 6 months after therapy cessation regarding days with daytime incontinence (from 3.94 [immediately after treatment] to 3.28 in 14 days [6 months after treatment cessation]), nocturnal enuresis (from 3.77 to 2.91 in 14 days), and urgency episodes (from 3.58 to 2.12 in 14 days) (p < 0.05). Complete response after 6 months of therapy was observed in 32% of patients with daytime incontinence, 35% with nocturnal enuresis, and 50% with urgency episodes.

DISCUSSION

A recent systematic review of parasacral TENS in children with OAB included only two studies with a follow up of 6 months or longer after treatment cessation; therefore, little is known about the continued effects of parasacral TENS. High rates of complete symptom remission were reported in studies where only subjective symptoms were evaluated. Results of our study reveal that the positive effect of treatment persist. The strengths of the present study include its prospective design, large sample size, and uniform standard urotherapy performed prior to TENS.

CONCLUSIONS

The use of parasacral TENS in children with OAB is effective and results in a significant reduction in daytime incontinence, nocturnal enuresis, and urgency episodes. A longer treatment duration of 4 months leads to more improvement and the effects remain stable 6 months after treatment cessation.

Sex and Gender Differences in the Pharmacology of the Overactive Urinary Bladder

Dysfunction of the lower urinary tract in general and the overactive bladder syndrome (OAB) in particular are prevalent and have major impact on the quality of life of the afflicted patients and their partners. We concisely review sex and gender differences in patients and animal models in physiological bladder function, its alterations in disease (mostly OAB), and its responses to treatment. Women appear to have a smaller functional bladder capacity and, therefore, must void more often than men. On the other hand, men have a greater bladder outlet resistance, which is partly attributed to a longer urethra and partly to the presence of the prostate. Sex and gender differences in bladder contractility appear small and were not found consistently. The ability of bladder smooth muscle to relax may be somewhat smaller in females. However, females are heavily underrepresented in experimental studies on bladder function. Stress urinary incontinence is found predominantly in women (particularly those after childbirth). OAB is similarly prevalent in men and women. Females seek treatment much more often and are overrepresented in clinical trials. Treatment responses in OAB patients are similar in both genders for oral medications, but improvements upon injections of onabotulinum toxin type A appear smaller in men. We conclude that there is no evidence for major sex and gender differences in bladder dysfunction as related to OAB and its treatment responses, but female animals are heavily underrepresented in experimental studies.