Bart L.H. Bemelmans

POSTERIOR TIBIAL NERVE STIMULATION AS NEUROMODULATIVE TREATMENT OF LOWER URINARY TRACT DYSFUNCTION

PURPOSE Recently, intermittent percutaneous posterior tibial nerve stimulation was introduced as a treatment modality filling the gap between conservative and surgical therapies in patients with certain types of lower urinary tract dysfunction. MATERIALS AND METHODS In a prospective multicenter trial posterior tibial nerve stimulation was evaluated in 37 patients who presented with symptoms of bladder overactivity, that is the urgency and frequency syndrome and/or urge incontinence, and 12 with nonobstructive urinary retention. Results were recorded in voiding diaries and on quality of life questionnaires before and after treatment. Patients were classified as responders, including those in whom therapy was successful and chose to continue treatment after the initial 12 weeks, and nonresponders, those who chose to stop treatment. RESULTS Overall, a positive response was seen in 60% of all patients. In patients with bladder overactivity a statistically significant decrease was observed in leakage episodes, number of pads used, voiding frequency and nocturia, and an equal increase in mean and smallest volume voided. Improvements were also seen in nonobstructive urinary retention, including number of catheterizations, total and mean volume catheterized, and total and mean volume voided. Disease specific quality of life and some domains of general quality of life improved, especially of bladder overactivity. Only mild side effects were observed. CONCLUSIONS Posterior tibial nerve stimulation is a minimally invasive and successful treatment option for patients with certain types of lower urinary tract dysfunction.

Sacral Root Neuromodulation in the Treatment of Refractory Urinary Urge Incontinence: A Prospective Randomized Clinical Trial

Objectives: To compare the effectiveness of sacral root neuromodulation with that of conservative management in ameliorating symptoms of refractory urinary urge incontinence and enhancing quality of life, to assess the objective response to neuromodulation as revealed by urodynamic testing, and to delineate the long–term outcomes of neuromodulation.Methods: Forty–four patients with refractory urge incontinence were randomized to undergo neuromodulation with an implantable impulse generator (n = 21) or to continue their prior conservative management (n = 23). At 6 months the control group was eligible for crossover to implant. Patient evaluation included voiding diaries, quality of life questionnaires, urodynamic testing, and documentation of adverse events. Long–term follow–up evaluations were conducted at 6–month intervals up to 36 months.Results: At 6 months mean leakage episodes, leakage severity and pad usage in the implant group were significantly lower by 88% (p < 0.0005), 24% (p = 0.047) and 90% (p < 0.0005), respectively, than the corresponding control group mean values. Improvements in leakage episodes and pad usage of ≥90% were attained by 75 and 85% of the implant group, respectively, but none of the control group. One third of implant patients, but none of the control patients, achieved ≥50% improvement in leakage severity. Over half of the implant patients (56%) were completely dry compared with 1 control patient (4%). Implant patients, but not control patients, exhibited significant improvement with respect to two quality of life measures. Neuromodulation resulted in increases of 220% (p < 0.0005) and 39% (p = 0.013), respectively, in urodynamically assessed bladder volume at first contraction and maximum fill. At 36 months the actuarial rate of treatment failure was 32.4% (95% CI, 17.0–56.0%). Adverse events most frequently involved pain at the implant site, and the incidence of serious complications was low.Conclusions: Neuromodulation is markedly more effective than conservative management in alleviating symptoms of refractory urge incontinence. Quality of life and urodynamic function are also improved by neuromodulation. The effects of neuromodulation are long–lasting, and associated morbidity is low.

Percutaneous tibial nerve stimulation in the treatment of refractory overactive bladder syndrome: is maintenance treatment necessary?

To determine the effect of a pause in percutaneous tibial nerve stimulation (PTNS) in successfully treated patients with an overactive bladder (OAB), and the reproducibility of successful treatment when restored.

Current opinion on the working mechanisms of neuromodulation in the treatment of lower urinary tract dysfunction.

Purpose of review Neuromodulation is a successful treatment for patients with refractory lower urinary tract dysfunction. In the recent years, more applications of various types and ways have been developed and put into clinical practice. It is important, therefore, for urologists to know the existing theories on the working mechanisms that explain the effect. Although much research has been devoted to this subject for the past 35 years, the working mechanism is still unknown. This review presents an overview of the different theories and research into the physiological background of neuromodulation during the past 3 decades with emphasis on recent developments. Recent findings Specific receptors in the spinal cord have been identified, which are involved in the working mechanism of neuromodulation. The maximal effect of neuromodulation is not directly reached, indicating that neuromodulation induces learning changes (i.e. neural plasticity). The carry-over effect could be caused by negative modulation of excitatory synapses in the central micturition reflex pathway. Summary Neuromodulation in the treatment of stress incontinence probably induces physiological changes in the sphincter muscles and pelvic floor. In the treatment of overactive bladder syndrome, nonobstructive voiding dysfunction and chronic pelvic pain, the mechanism of action seems to be more complicated. Most likely, it is a combination of the different suggested modes of action, involving the neuroaxis at different levels.

Erectile Dysfunction in Diabetic Men: The Neurological Factor Revisited

In the literature the importance of the neurological factor in the etiology of erectile dysfunction in patients with diabetes mellitus is subject to debate. We report on the findings of neurophysiological investigations in 27 impotent and 30 potent diabetic patients, as well as 102 impotent nondiabetic patients. Additionally, hormonal and vascular evaluations were done. The neurophysiological evaluations consisted of assessment of somatic as well as autonomic sensory nerves, by measuring the latencies of somatosensory evoked potentials of the posterior tibial and pudendal nerves, and of the bulbocavernosus and urethro-anal reflexes. The results show a higher incidence of more severe peripheral and autonomic sensory neuropathy in impotent diabetic men. Also, a preponderance of abnormal intracavernous pharmacological tests, suggesting vasculogenic impotence, was found in impotent diabetic patients. No important endocrinological differences were found among the 3 groups under investigation. Significant differences occurred for plasma glucose and glycosylated hemoglobin. We conclude that diabetic urogenital sensory neuropathy has a crucial role in the etiology of diabetic impotence. Angiopathy seems to be of secondary importance. The results show that poor diabetes regulation is associated with diabetic impotence.

Assessment of penile blood flow by duplex ultrasonography in 44 men with normal erectile potency in different phases of erection.

Duplex ultrasonography is important in the diagnosis of vasculogenic erectile dysfunction. We measured the ultrasonographic parameters of cavernous blood flow in different phases of penile erection. We examined 44 volunteers with normal erectile potency. Doppler spectra of the cavernous artery were obtained in a time-dependent manner after intracavernous administration of papaverine. Following intracavernous pharmacological stimulation, the Doppler spectrum alters according to a specific pattern indicating the different hemodynamic phases of erection. Peak flow velocity and acceleration time, measured in the early post-injection phase, may be used to grade arterial inflow. The difference between resistance index in the pre-injection and late post-injection phases may be used to estimate veno-occlusive function. References values are defined.

Evidence for Early Lower Urinary Tract Dysfunction in Clinically Silent Multiple Sclerosis

The occurrence of micturition complaints as late sequelae of multiple sclerosis is well studied and documented. However, no reports exist on urologically asymptomatic patients with a relatively short disease duration. In a prospective study of 40 patients with definite multiple sclerosis (mean disease duration 5 years), urodynamic investigations (cystometry and pressure-flow study) were combined with neuro-urophysiological measurements (cortical evoked potentials and sacral reflex latencies). Patients with (13) and without (27) micturition complaints were investigated. Neurourodynamic abnormalities were seen in 35 of 40 patients (88%). The lower urinary tract proved to be afflicted by multiple sclerosis at an early stage of the disease. Early neurourodynamic investigations had clinical implications. All of the complaining and half of the noncomplaining patients showed urodynamic abnormalities upon which the need for further followup and eventual therapeutic intervention was based. We conclude that neurourodynamic testing of a urinary functional system can be worthwhile as part of the initial diagnostic evaluation in patients with proved multiple sclerosis.

Penile Sensory Disorders in Erectile Dysfunction: Results of a Comprehensive Neuro-Urophysiological Diagnostic Evaluation in 123 Patients

A total of 123 patients with complaints of erectile dysfunction and no clinically overt neurological disease underwent a comprehensive neuro-urophysiological diagnostic evaluation. The results were compared with those obtained in 50 healthy volunteers. Data gathered consisted of somatosensory evoked potentials from the posterior tibial nerve (tibial evoked potential) and from the dorsal penile nerve (pudendal evoked potential). Also, 2 sacral reflex latencies were measured (bulbocavernosus reflex and urethro-anal reflex). A total of 58 patients (47%) had at least 1 abnormal neuro-urophysiological measurement. Neuro-urophysiological abnormalities were found more frequently in older patients. The tibial evoked potential was abnormal in 30 patients (24%), pudendal evoked potential in 21 (17%), bulbocavernosus reflex in 26 (21%) and urethro-anal reflex in 32 (26%). It was concluded that somatosensory disturbances constitute an important part of neuro-urophysiological abnormalities. Our results suggest a relationship between erectile dysfunction and subclinical, age-related (penile) sensory disorders. Our study corroborates the importance of penile sensibility for erectile (patho)physiology as suggested by others and supports the concept of sensory deficit impotence as an important cause of erectile dysfunction.

The prevalence of urinary incontinence in community‐dwelling married women: a matter of definition

To determine the prevalence of female urinary incontinence (UI) and its impact on quality of life.

Posterior tibial nerve stimulation in the treatment of idiopathic nonobstructive voiding dysfunction.

OBJECTIVES To evaluate the effect of stimulation of the posterior tibial nerve in the treatment of voiding dysfunction. METHODS Thirty-nine patients with chronic voiding dysfunction necessitating clean intermittent catheterization were enrolled in a prospective multicenter trial in the Netherlands (n = 19) and Italy (n = 20). They underwent 12 weekly sessions of posterior tibial nerve stimulation. Frequency/volume charts, an incontinence quality-of-life instrument, and the MOS 36-item Short-Form Health Survey were completed at 0 and 12 weeks. Subjective success was defined by the patients positive response resulting in a request to continue treatment. Efficacy was based on analysis of the frequency/volume charts comparing the baseline values with the data at 12 weeks. A reduction of 50% or more in total catheterized volume was considered as an objective success (primary outcome measurement). RESULTS Of the 39 patients, 23 (59%) chose to continue treatment. The frequency/volume charts showed a 50% decrease in total catheterized volume in 16 (41%) of 39 patients. Additionally, 10 patients (26%) noted a reduction of 25% to 50% in their total catheterized volume. For all patients, the total catheterized volume decreased by a mean of -228 mL (range -49 to -528). The incontinence quality-of-life instrument and Short-Form Health Survey parameters improved significantly. CONCLUSIONS Percutaneous stimulation of the posterior tibial nerve seems to be an effective, minimally invasive option worth trying in patients with idiopathic voiding dysfunction. Improvement was seen in objective micturition parameters, as well as in subjective quality-of-life data.