Chiharu Shibata

Neuromodulation for the Treatment of Lower Urinary Tract Symptoms

Neuromodulation therapy incorporates electrical stimulation to target specific nerves that control lower urinary tract symptoms (LUTS). The objectives of this article are to review the mechanism of action, the type of neuromodulation, and the efficacy of neuromodulation mainly according to the results of randomized controlled trials. Neuromodulation includes pelvic floor electrical stimulation (ES) using vaginal, anal and surface electrodes, interferential therapy (IF), magnetic stimulation (MS), percutaneous tibial nerve stimulation, and sacral nerve stimulation (SNS). The former four stimulations are used for external periodic (short‐term) stimulation, and SNS are used for internal, chronic (long‐term) stimulation. All of these therapies have been reported to be effective for overactive bladder or urgency urinary incontinence. Pelvic floor ES, IF, and MS have also been reported to be effective for stress urinary incontinence. The mechanism of neuromodulation for overactive bladder has been reported to be the reflex inhibition of detrusor contraction by the activation of afferent fibers by three actions, i.e., the activation of hypogastric nerve, the direct inhibition of the pelvic nerve within the sacral cord and the supraspinal inhibition of the detrusor reflex. The mechanism of neuromodulation for stress incontinence is contraction of the pelvic floor muscles through an effect on the muscle fibers as well as through the stimulation of pudendal nerves. Overall, cure and improvement rates of these therapies for urinary incontinence are 30–50, and 60–90% respectively. MS has been considered to be a technique for stimulating nervous system noninvasively. SNS is indicated for patients with refractory overactive bladder and urinary retention.

Tolterodine activates the prefrontal cortex during bladder filling in OAB patients: A real-time NIRS-urodynamics study

Studies of overactive bladder (OAB) have shown urothelial/suburothelial changes and increased bladder afferents, while in the brain the frontal micturition area that normally suppresses the bladder is deactivated. It has been unclear whether anticholinergic medication could reverse this suppression. To address this question, we performed a real‐time NIRS (near‐infrared spectroscopy)‐urodynamic study in OAB patients before and after the administration of an anticholinergic agent, tolterodine.

The role of muscarinic receptor subtypes on carbachol-induced contraction of normal human detrusor and overactive detrusor associated with benign prostatic hyperplasia

The aim of this study was to compare the effect of antimuscarinic antagonists on carbachol-induced contraction of normal human bladder and detrusor overactivity associated with benign prostatic hyperplasia (DO/BPH). Samples of human bladder muscle were obtained from patients undergoing total cystectomy for bladder cancer (normal bladder), and those undergoing retropubic prostatectomy for BPH. All of the patients with DO/BPH had detrusor overactivity according to urodynamic studies. Detrusor muscle strips were mounted in 10-ml organ baths containing Krebs solution, and concentration-response curves for carbachol were obtained in the presence of antimuscarinic antagonists (4-DAMP, methoctramine, pirenzepine, tolterodine, solifenacin, trospium, propiverine, oxybutynin, and imidafenacin) or vehicle. All antagonists competitively antagonized concentration-response curves to carbachol with high affinities in normal bladder. The rank order of mean pA2 values was as follows: trospium (10.1) > 4-DAMP (9.87), imidafenacin (9.3) > solifenacin (8.8) > tolterodine (8.6) > oxybutynin (8.3) > propiverine (7.7) > pirenzepine (7.4) > methoctramine (6.6). The effects of these antimuscarinic antagonists did not change when tested with DO/BPH bladder, suggesting that each antimuscarinic antagonist has a similar effect in this condition. Schild plots showed a slope corresponding to unity, except for propiverine with DO/BPH detrusor. In conclusion, M3-receptors mainly mediate contractions in human bladder strips with normal state and DO/BPH.

Six-year follow up of silodosin monotherapy for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia: What are the factors for continuation or withdrawal?

To investigate the factors for continuation or withdrawal as an extension of a prospective study of silodosin monotherapy for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia for more than 6 years.