Nerve stimulation for chronic pelvic pain and bladder pain syndrome: a systematic review

Transcutaneous Tibial Nerve Stimulation for Pain Management in Women with Primary Dysmenorrhea: A Randomized Clinical Trial

Primary dysmenorrhea is considered one of the main causes of pelvic pain during a woman's childbearing years, resulting in poor quality of life. The objective was to evaluate the effectiveness of transcutaneous tibial nerve stimulation (TTNS) in painful symptomatology improvement and non-steroidal anti-inflammatory drug (NSAID) intake reduction in women with primary dysmenorrhea (PD) compared with a control group in the short, medium, and long terms. A single-blind, controlled clinical trial was developed. Participants were randomized to the experimental (TTNS) and control group (sham TTNS). Both groups received 12-weekly 30-min sessions with a NeuroTracTM PelviTone electrostimulation device. The intensity and severity of pain and non-steroidal anti-inflammatory drug (NSAID) intake were evaluated in the short-term (after treatment), medium-term (1-3 months), and long-term (6 months). A total of 61 participants were randomized, with a split of 31 (experimental group) and 30 (control group), but 55 participants completed the study and were analyzed. Statistically significant differences between both groups in the maximum pain intensity decrease (F = 4.88, p = 0.0043) measured with the visual analogue scale, as well as NSAID intake decrease (F = 4.68, p = 0.011) and days of their ingestion (F = 4.57, p = 0.012) occurred in the short term. Furthermore, significant decreases in the total number of NSAIDs ingested during the cycle (F = 3.82, p = 0.011) and the number of days on which patients ingested NSAIDs (F = 3.59, p = 0.015) in the medium-long term occurred. TTNS could be an effective and safe strategy to reduce pain caused by PD, which could reduce or complement the use of pharmacological techniques and other more invasive methods.

Effect of knack technique on vaginal laxity in multiparous women: A randomized controlled trial

BACKGROUND

Vaginal laxity defined according to the International Urogynecological Association/International Continence society is excessive vaginal looseness; it is one of the most common symptoms of pelvic floor dysfunction, which refers to medical/functional disorders that can have a significant impact on a woman's sexual self-esteem and sexual life.

AIM

This study aimed to determine the impact of the Knack Technique on Pelvic floor muscle (PFM) and sexual function in women with vaginal laxity.

METHODS

Thirty females complaining of vaginal laxity were randomly chosen from the outpatient clinic at Deraya University. Their ages varied from 35 to 45 years, their body mass index was 25-30 kg/m2, and a number of parities ≤ three normal vaginal deliveries and at least two years from the last delivery complaining about vaginal laxity, water entrapment, and loss of friction during sexual intercourse. They were randomized into two equal groups at random (A, B). Group A (15 females) received (PSTES) and group B (15 females) received (PSTES) and Knack Technique. Both the groups received three sessions per week for 2 months.

EVALUATION

The outcome measures were evaluated through pre- and post-interventions by using ultrasonography imaging to assess PFM function, Sexual Satisfaction Index, and Vaginal Laxity Questionnaires (VLQ) to assess sexual function.

RESULTS

Analysis indicated a significant improvement in vaginal laxity in the two groups. Comparison between groups pre- and posttreatment showed that there was no statistically significant difference between the groups B and A in SSI and VLQ, while there were significant differences between the groups A and B in PFM force.

CONCLUSION

Combining Parasacral transcutaneous electrical stimulation (PSTES) and Knack Technique is more effective than PSTES alone in reducing vaginal laxity as well as improving PFM and sexual function in women with vaginal laxity.

Transcutaneous Tibial Nerve Stimulation for Primary Dysmenorrhea: A Protocol for a Randomized Controlled Trial

Primary dysmenorrhea (PD) is a painful menstruation that can persist for the duration of a woman's fertile life. Non-steroidal anti-inflammatory drugs, hormonal therapy, physiotherapy techniques, etc., are the main treatments. The main objective of this study is to evaluate the effectiveness of transcutaneous posterior tibial nerve stimulation (TTNS) in PD patients. The study will consist of a single-blind randomized clinical trial, parallel-assigned with two arms. Women with PD (18-43 years) with regular menstrual cycles and at least 4 points in VAS will be randomly divided into experimental (TTNS) and placebo (simulated stimulation) groups during 12 treatment sessions (1 session/week) and several follow-ups: monthly during treatment and 1, 3 and 6 months after. Maximum and mean pain intensity, pain duration, pain severity, number of anti-inflammatory drugs, quality of life, sleep quality, overall improvement, treatment satisfaction and secondary effects will be measured once a month every 6 months and at 3 and 6 months. The Student's t-test for independent samples or the Mann-Whitney U test will be used. The literature shows effective physiotherapeutic techniques for PD in the short term, which do not act on causes and have limitations. The TTNS technique can be used in transcutaneous and percutaneous modalities, with similar effectiveness, but the transcutaneous causes less discomfort. TTNS modulates pain, and long-term benefits could be achieved at low cost and without patient discomfort.

Neuromodulation in Chronic Pelvic Pain: A Narrative Review

Chronic primary pelvic pain syndrome (CPPPS) is a heterogeneous disease with unknown pathogenesis and a lack of distinct pathological features, which complicates diagnosis and therapy and has a significant impact on patients' daily life. Because pharmacological management is ineffective and long-term use may result in additional system damage, developing a more effective treatment is critical. Neuromodulation has advanced rapidly over the last few decades, and various types of neuromodulations have demonstrated efficacy in the treatment of CPPPS. In this article we discuss the evolution of neuromodulation technology in the treatment of chronic pelvic pain, its application to various subtypes of chronic pelvic pain, and the comparison of relevant efficacy and parameter differences, as well as assess the relative advantages and disadvantages of sacral neuromodulation, percutaneous tibial nerve stimulation , transcutaneous electrical nerve stimulation, electroacupuncture, and pudendal neuromodulation. Furthermore, it was noted that chronic pelvic pain should be evaluated in terms of pain, associated symptoms, psychological problems, and quality of life. Although neuromodulation approaches have been shown to be effective in treating chronic pelvic pain, more extensive multicenter trials are required to confirm this.

Does TENS Reduce the Intensity of Acute and Chronic Pain? A Comprehensive Appraisal of the Characteristics and Outcomes of 169 Reviews and 49 Meta-Analyses

Background and Objectives: Uncertainty about the clinical efficacy of transcutaneous electric nerve stimulation (TENS) to alleviate pain spans half a century. There has been no attempt to synthesise the entire body of systematic review evidence. The aim of this comprehensive review was to critically appraise the characteristics and outcomes of systematic reviews evaluating the clinical efficacy of TENS for any type of acute and chronic pain in adults. Materials and Methods: We searched electronic databases for full reports of systematic reviews of studies, overviews of systematic reviews, and hybrid reviews that evaluated the efficacy of TENS for any type of clinical pain in adults. We screened reports against eligibility criteria and extracted data related to the characteristics and outcomes of the review, including effect size estimates. We conducted a descriptive analysis of extracted data. Results: We included 169 reviews consisting of eight overviews, seven hybrid reviews and 154 systematic reviews with 49 meta-analyses. A tally of authors' conclusions found a tendency toward benefits from TENS in 69/169 reviews, no benefits in 13/169 reviews, and inconclusive evidence in 87/169 reviews. Only three meta-analyses pooled sufficient data to have confidence in the effect size estimate (i.e., pooled analysis of >500 events). Lower pain intensity was found during TENS compared with control for chronic musculoskeletal pain and labour pain, and lower analgesic consumption was found post-surgery during TENS. The appraisal revealed repeated shortcomings in RCTs that have hindered confident judgements about efficacy, resulting in stagnation of evidence. Conclusions: Our appraisal reveals examples of meta-analyses with 'sufficient data' demonstrating benefit. There were no examples of meta-analyses with 'sufficient data' demonstrating no benefit. Therefore, we recommend that TENS should be considered as a treatment option. The considerable quantity of reviews with 'insufficient data' and meaningless findings have clouded the issue of efficacy. We offer solutions to these issues going forward.

Statewide Success of Staged Sacral Neuromodulation for the Treatment of Urinary Complaints in California (2005-2011)

PURPOSE

Sacral neuromodulation (SNS) is approved by the Food and Drug Administration as a third-line treatment for refractory overactive bladder, idiopathic urinary retention, and fecal incontinence. Prior to implantation of an implantable pulse generator, all patients undergo a trial phase to ensure symptom improvement. The published success rates of progression from the test phase to permanent implant vary widely (range, 24% to >90%). We sought to characterize success rates using a statewide registry.

METHODS

Using nonpublic data, we identified SNS procedures using the California Office of Statewide Planning and Development ambulatory surgery database from 2005 to 2011. A successful trial was defined as receiving a stage 2 generator implantation after trial lead placement. Multivariable logistic regression was performed to identify factors associated with staged success.

RESULTS

During the study period, 1396 patients underwent a staged SNS procedure, with 962 (69%) subsequently undergoing generator placement. Successful trial rates were 72% for overactive bladder wet, 69% for urgency/frequency, 68% for interstitial cystitis, 67% for neurogenic bladder, and 57% for urinary retention. On multivariate logistic regression, only male sex (odds ratio, 0.51) and urinary retention [odds ratio, 0.54) were significantly associated with lower odds of success, whereas age, race/ethnicity, medical insurance, and placement at an academic or high-volume institution had no association.

CONCLUSIONS

The "real world" success rates for staged SNS implantation in California are less than those observed by some academic centers of excellence but better than previously reported for Medicare beneficiaries. Successful trial rates for interstitial cystitis and neurogenic voiding dysfunction are similar to refractory overactive bladder.

Potential of Electrical Neuromodulation for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a common chronic inflammatory disease of the digestive tract that is often debilitating. It affects patients' quality of life and imposes a financial burden. Despite advances in treatment with medications such as biologics, a large proportion of patients do not respond to medical therapy or develop adverse events. Therefore, alternative treatment options such as electrical neuromodulation are currently being investigated. Electrical neuromodulation, also called bioelectronic medicine, is emerging as a potential new treatment for IBD. Over the past decade, advancements have been made in electrical neuromodulation. A number of electrical neuromodulation methods, such as vagus nerve stimulation, sacral nerve stimulation, and tibial nerve stimulation, have been tested to treat IBD. A series of animal and clinical trials have been performed to evaluate efficacy with promising results. Although the exact underlying mechanisms of action for electrical neuromodulation remain to be explored, this modality is promising. Further randomized controlled trials and basic experiments are needed to investigate efficacy and clarify intrinsic mechanisms.

Medications used to treat bladder disorders may alter effects of neuromodulation

AIMS

Neuromodulation (nerve stimulation) can produce analgesia. One form, bilateral pudendal nerve stimulation (bPNS), suppresses responses to urinary bladder distension (UBD) in hypersensitive rats. Drugs can modify this effect (eg, benzodiazepines, but not opioids, suppress bPNS effects). Prior to a clinical trial of bPNS effects on bladder pain, we felt it was prudent to survey the effects of medications commonly used in patients with bladder disorders.

METHODS

Bladder hypersensitivity was produced by neonatal bladder inflammation in rat pups coupled with a second inflammatory insult as an adult. Antimuscarinic (oxybutynin), β₃ -adrenoceptor agonist (mirabegron, CL316243), α₁ -adrenoceptor antagonist (tamsulosin), antidepressant (amitriptyline), muscle relaxing (baclofen), and sedative (propofol) agents were administered and effects of bPNS on responses to UBD assessed. bPNS consisted of bilateral biphasic electrical stimulation of the mixed motor/sensory component of the pudendal nerves. Visceromotor responses (VMRs; abdominal muscle contractile responses) were used as nociceptive endpoints.

RESULTS

Many of these drugs directly inhibited the VMRs to UBD, but only mirabegron, at the doses employed, significantly reduced inhibitory effects of bPNS. In the presence of the other drugs, bPNS continued to produce statistically significant inhibition of VMRs to UBD.

CONCLUSIONS

This study suggests that concurrent therapy with drugs used to treat bladder disorders could affect assessment of the effects of bPNS on bladder hypersensitivity. This study gives guidance to clinical trials using bPNS for the treatment of painful bladder syndromes and suggests potential clinical use of some of these medications in the treatment of these same disorders.

Outcomes of sacral neuromodulation for chronic pelvic pain: a Finnish national multicenter study

BACKGROUND

The aim of this study was to report the outcomes of sacral neuromodulation (SNM) in chronic pelvic pain (CPP) patients in the Finnish national cohort.

METHODS

This was a register-based retrospective study, involving all the centers that provide SNM treatment in Finland. The data of all patients treated with SNM for CPP were gathered from Oulu-, Turku-, Tampere- and Helsinki University Hospitals, as well as Jyväskylä and Seinäjoki Central Hospitals. All patients who had been tested for SNM implantation prior to April 2017 were included in the study.

RESULTS

A total of 51 patients were selected for SNM treatment due to CPP from 2004 until 2017. The mean follow-up time was 13.8 months (SD 22.9 months). A total of 28 patients (57%) advanced from testing to permanent stimulator implantation. There were 21 patients (41%) who had a working modulator implanted at the end of follow-up. Patients with endometriosis-related pain had a significantly higher permanent implantation rate than the overall implantation rate (88% vs. 57%; p = 0.01). The endometriosis patients also had a higher overall success rate by the end of the follow-up (75% vs. 41%; p = 0.026) CONCLUSIONS: SNM may be a viable treatment option for patients with CPP due to endometriosis. Further research on SNM treatment for endometriosis patients with refractory CPP is needed.

Balance ability and posture in postmenopausal women with chronic pelvic pain

OBJECTIVE

The aim of the present study was to analyze balance ability and posture in postmenopausal women with chronic pelvic pain (CPP).

METHODS

This study includes a sample of 48 women with CPP recruited from the Gynecology Service of Virgen de las Nieves and San Cecilio Hospitals in Granada (Spain) and 48 healthy control women matched with respect to age and anthropometric characteristics. Outcome variables collected included: balance ability (Mini-Balance Evaluation Systems Test and Timed Up an Go Test) and posture (photogrammetry and Spinal Mouse).

RESULTS

Significant differences were found in all Mini Best Test subscales: total (P < 0.001), anticipatory (P = 0.002), reactive postural control (P < 0.001), sensory orientation (P < 0.001), and dynamic gait (P < 0.001), and all Timed Up and Go test subscales: alone (P < 0.001), with manual (P = 0.002) and cognitive task (P = 0.030). Significant differences were also found on spinal cervical angles with a forward head posture in women with CPP; global spine alignment exhibited more deviation in the women with CPP (P < 0.001); and a higher percentage of women with CPP (58%) presented with increased thoracic kyphosis and lumbar lordosis. Cohen's d was used to calculate the effect size. Some subscales of balance and posture tests showed a large effect size (d ≥0.8), indicating a more consistent result.

CONCLUSIONS

Women with CPP presented poor balance including anticipatory, reactive postural control, sensory orientation, dynamic gait, and dual task-related conditions. Posture showed higher values on the dorsal angle and lower sacral inclination, less spine alignment, and a more prevalent posture with increased kyphosis and lumbar lordosis.

Benzodiazepines Suppress Neuromodulatory Effects of Pudendal Nerve Stimulation on Rat Bladder Nociception

BACKGROUND

Neuromodulation, as a therapeutic modality for pain treatment, is an alternative to opioid therapies and therefore receiving increased interest and use. Neuromodulation at a peripheral nerve target, in the form of bilateral electrical pudendal nerve stimulation (bPNS), has been shown to reduce bladder hypersensitivity in rats and anecdotally reduces pain in humans with pelvic pain of urological origin. Recent studies have identified a role for spinal γ-aminobutyric acid (GABA) receptors in this effect. Concomitant medication use, such as benzodiazepines, could alter responses to neuromodulation, and so before the development of a clinical trial to confirm translation of this potential therapy, the potential interactions between acute and chronic use of benzodiazepines and bPNS were examined in a preclinical model.

METHODS

Bladder hypersensitivity was produced by neonatal bladder inflammation in rat pups coupled with a second inflammatory insult as an adult. Diazepam (1-5 mg/kg intraperitoneal [i.p.]) or vehicle was administered acutely (with or without bPNS) and chronically (5 mg/kg subcutaneous [s.c.] daily for 2 weeks before the final experiment). bPNS was delivered as bilateral biphasic electrical stimulation of the mixed motor/sensory component of the pudendal nerves. Visceromotor responses (VMRs; abdominal muscle contractile responses to urinary bladder distension [UBD]) were used as nociceptive end points. Due to the profound effects of diazepam, the effect of midazolam (0.5-1.0 mg/kg i.p.) on VMRs and bPNS effects was also studied.

RESULTS

Diazepam and midazolam both produced a dose-dependent, flumazenil-reversible inhibition of VMRs to UBD. bPNS resulted in statistically significant inhibition of VMRs to UBD in hypersensitive rats that had received vehicle injections. Select doses of diazepam and midazolam suppressed the inhibitory effect of bPNS on VMRs.

CONCLUSIONS

This study suggests that inhibitory effects of bPNS on bladder pain could be suppressed in subjects receiving benzodiazepine therapy, suggesting that potential clinical testing of pudendal nerve stimulation for the treatment of painful bladder syndromes may be confounded by the use of benzodiazepines. Clinical assessment of other forms of neuromodulation should also be screened for impacts of benzodiazepines.

Neuromodulatory effects of pudendal nerve stimulation on bladder hypersensitivity are present in opioid-pretreated rats

BACKGROUND AND OBJECTIVES

Bilateral electrical pudendal nerve stimulation (bPNS) reduces bladder hypersensitivity in rat models and anecdotally reduces pain in humans with pelvic pain of urologic origin. Concomitant opioids are known to alter responses to neuromodulation in some systems. So prior to the development of a clinical trial for purposes of regulatory approval, the preclinical interaction between opioids and stimulation effectiveness was examined.

METHODS

Bladder hypersensitivity was produced by neonatal bladder inflammation in rat pups coupled with a second inflammatory insult as an adult. Morphine was administered acutely (1-4 mg/kg intraperitoneal) or chronically (5 mg/kg subcutaneously daily for 2 weeks prior to the terminal experiment). bPNS consisted of bilateral biphasic electrical stimulation of the mixed motor/sensory component of the pudendal nerves. Visceromotor responses (VMR; abdominal muscle contractile responses to urinary bladder distension (UBD)) were used as nociceptive endpoints.

RESULTS

Morphine produced a dose-dependent inhibition of VMRs to UBD that was naloxone reversible. bPNS resulted in statistically significant inhibition of VMRs to UBD in hypersensitive rats that had received acute or chronic subcutaneous morphine injections.

CONCLUSIONS

This study suggests that inhibitory effects of bPNS can still be evoked in subjects who are receiving opioid therapy, thus giving guidance to potential clinical trials seeking regulatory approval for the treatment of chronic bladder pain.

Sacral neuromodulation treating chronic pelvic pain: a meta-analysis and systematic review of the literature

INTRODUCTION AND HYPOTHESIS

Sacral neuromodulation (SNM) is gaining popularity as a treatment option for chronic pelvic pain (CPP). Our hypothesis is that SNM is effective in improving CPP.

METHODS

A systematic search was conducted through September 2018. Peer-reviewed studies using pre- and postpain intensity scores were selected. The primary outcome was pain improvement on a 10-point visual analog scale (VAS) (adjusted or de novo) in patients with CPP. Secondary outcomes included comparing SNM approaches and etiologies and evaluating lower urinary tract symptoms (LUTS).

RESULTS

Fourteen of 2175 studies, evaluating 210 patients, were eligible for further analysis. The overall VAS pain score improvement was significant [weighted mean difference (WMD) -4.34, 95% confidence interval (CI) = -5.22, to-3.64, p < 0.0001)]. Regarding SNM approach, both standard and caudal approaches had significant reduction in pain scores: WMD -4.32, CI 95% = -5.32, to -3.31 (p < 0.001) for the standard approach, compared with WMD -4.63, 95% CI = -6.57 to -2.69 (P < 0.001), for the caudal approach (p = 0.75). While significant improvement in pain was observed both in patients with and without interstitial cystitis/bladder pain syndrome (IC/BPS), the observed improvement was lower in patients with (WMD -4.13, CI 95% -5.36 to -2.90 versus without (WMD -5.72, CI 95% = -6.18, to-5.27) IC/BPS (p = 0.02). SNM was effective in treating voiding symptoms (frequency, urgency, nocturia) associated with IC/BPS (all p < 0.01).

CONCLUSIONS

SNM is an effective therapy for CPP in both IC/BSP and non-IC/BSP patients, with better results in non-IC/BSP patients. Outcomes of the antegrade caudal approach were comparable with the standard retrograde approach.

Efficacy and Safety of Sacral and Percutaneous Tibial Neuromodulation in Non-neurogenic Lower Urinary Tract Dysfunction and Chronic Pelvic Pain: A Systematic Review of the Literature

CONTEXT

Neuromodulation is considered in patients with non-neurogenic lower urinary tract dysfunction (LUTD) not responsive to conservative treatment.

OBJECTIVE

To systematically review the available studies on efficacy and safety of sacral neuromodulation (SNM) and percutaneous tibial nerve stimulation (PTNS) in non-neurogenic LUTDs not responsive to conservative treatments.

EVIDENCE ACQUISITION

A literature research was conducted in PubMed/Medline and Scopus, restricted to articles in English, published between January 1998 and June 2017, with at least 20 patients and 6 mo of follow-up.

EVIDENCE SYNTHESIS

Twenty-one reports were identified. Concerning SNM, the improvement of ≥50% in leakage episodes ranged widely between 29% and 76%. Overall dry rate ranged between 43% and 56%. Overall success/improvement rate in PTNS varied between 54% and 59%. Symptom improvement or efficacy in interstitial cystitis/bladder pain syndrome patients appeared to be lower compared with other indications in both techniques. Safety data showed fewer side effects in patients submitted to PTNS.

CONCLUSIONS

Neuromodulation gives good results and is a safe therapy for patients with overactive bladder or chronic nonobstructive urinary retention with long-lasting efficacy. Moreover, PTNS has been shown to have good success rates and fewer side effects compared with SNM. These data have to be confirmed with long-term follow-up.

PATIENT SUMMARY

Sacral neuromodulation can improve low urinary tract symptoms in selected patients; it appears to be a safe therapy for nonresponders to standard medical therapies. Percutaneous tibial nerve stimulation (PTNS) is a less invasive technique that gives good results in short time with fewer side effects. However, we must consider that PTNS has not been tested in the long term and results are lower if compared with SNM.

Role of sacral neuromodulation in modern urogynaecology practice: a review of recent literature

Sacral neuromodulation (SNM) offers promise in the therapy of many pelvic floor disorders. This innovative treatment has slowly gained popularity. A review of recent literature is presented in relation to its efficacy and complications in various pelvic floor conditions: overactive bladder and urge urinary incontinence, chronic urinary retention, painful bladder syndrome, pelvic pain and double incontinence. It is a minimally invasive, completely reversible safe procedure with good long-term outcomes. However, the treatment is costly, the revision rate is high and patients require life-long follow-up. SNM should always be considered in suitable patients before offering bladder augmentation procedures or urinary diversion or permanent catheterization for bladder dysfunction. SNM should also be considered in patients with double incontinence, after discussion in a urogynaecology/colorectal multidisciplinary team.

Screening and Optimization of Nerve Targets and Parameters Reveals Inhibitory Effect of Pudendal Stimulation on Rat Bladder Hypersensitivity

BACKGROUND AND OBJECTIVES

Neuromodulation has been reported to reliably improve symptoms of bladder overactivity and sometimes pain. The effect of electrical stimulation of several nerve pathways demonstrated to alter cystometric responses to bladder distension was examined on nociceptive responses in models of bladder hypersensitivity.

METHODS

Bladder hypersensitivity was produced by several published methods including neonatal inflammation, acute inflammation, and chronic stress. Effects of different sites of stimulation (L6 and T13 nerve roots, proximal and distal pudendal nerves [PNs]) on nociceptive reflex responses to urinary bladder distension in urethane-anesthetized female rats were assessed and a parametric analysis of parameters of stimulation was performed.

RESULTS

Bilateral biphasic stimulation of the proximal PNs resulted in statistically significant inhibition of visceromotor and cardiovascular responses to bladder distension in rats made hypersensitive by neonatal bladder inflammation. We found a range of optimal stimulation frequencies (5-10 Hz) which produced robust inhibitory effects when using short pulse widths (100-240 μs). Onset of inhibition was within minutes and persisted for several minutes after the stimulus was discontinued. Use of bilateral PN stimulation in acute inflammation and stress-induced hypersensitivity models as well as unilateral stimulation, very distal PN cutaneous branch stimulation, and stimulation of the T13 and L6 nerve roots all proved ineffective with the parameters used.

CONCLUSIONS

This study suggests that inhibitory effects of bilateral PN stimulation can be evoked in a rodent hypersensitivity model at relatively low frequencies with short pulse widths. The onset of effect is rapid, which suggests the potential for treating episodic pain in painful bladder disorders.

Anorectal and Pelvic Pain

Although pelvic pain is a symptom of several structural anorectal and pelvic disorders (eg, anal fissure, endometriosis, and pelvic inflammatory disease), this comprehensive review will focus on the 3 most common nonstructural, or functional, disorders associated with pelvic pain: functional anorectal pain (ie, levator ani syndrome, unspecified anorectal pain, and proctalgia fugax), interstitial cystitis/bladder pain syndrome, and chronic prostatitis/chronic pelvic pain syndrome. The first 2 conditions occur in both sexes, while the latter occurs only in men. They are defined by symptoms, supplemented with levator tenderness (levator ani syndrome) and bladder mucosal inflammation (interstitial cystitis). Although distinct, these conditions share several similarities, including associations with dysfunctional voiding or defecation, comorbid conditions (eg, fibromyalgia, depression), impaired quality of life, and increased health care utilization. Several factors, including pelvic floor muscle tension, peripheral inflammation, peripheral and central sensitization, and psychosocial factors, have been implicated in the pathogenesis. The management is tailored to symptoms, is partly supported by clinical trials, and includes multidisciplinary approaches such as lifestyle modifications and pharmacological, behavioral, and physical therapy. Opioids should be avoided, and surgical treatment has a limited role, primarily in refractory interstitial cystitis.

Does central sensitization help explain idiopathic overactive bladder?

The pathophysiological mechanisms underlying overactive bladder syndrome (OAB) can include dysfunction of sensory pathways of the peripheral and central nervous systems, resulting in bladder hypersensitivity. Central sensitization describes an induced state of spinal hypersensitivity that is associated with a variety of chronic pain disorders that share many attributes with OAB, albeit without the presence of pain. As such, the concept of central sensitization might be relevant to understanding the mechanisms and clinical manifestations of OAB syndrome. An understanding of the pathophysiology and clinical manifestations of central sensitization, and the evidence that supports a role of central sensitization in OAB, including the potential implications of mechanisms of central sensitization for the treatment of patients with OAB could provide a novel approach to the treatment of patients with this disease. Such an approach would be especially relevant to those patients with central sensitization-related comorbidities, and has the potential to improve the outcomes of these patients in particular.

Neuromodulation for the Treatment of Endometriosis-Related Symptoms

Sacral and pudendal neuromodulation have been advocated for the treatment of refractory pelvic pain, urinary urgency and retention, as well as fecal incontinence or constipation, all of which are commonly related to endometriosis and/or its surgical treatment.

In this review, the mechanisms of action and different routes of neuromodulation will be detailed, as well as all the studied applications of neuromodulation on ameliorating symptoms related to endometriosis and/or its treatment.

Complementary therapies for bladder pain syndrome: a systematic review

Introduction and hypothesis

Bladder pain syndrome is a difficult condition to treat. The purpose of this systematic review is to assess the effectiveness of various complementary therapies available for treatment.

Methods

This review was conducted in adherence with Preferred Reporting Items for Systematic Reviews. Citations were retrieved using a comprehensive database search (from inception to July 2014: CINAHL, Cochrane, EMBASE, Medline and SIGEL and grey literature). Studies that fulfilled the inclusion criteria were selected. Eligibility consisted of women with bladder pain syndrome, an intervention of alternative/complementary therapies and an outcome of improvement of symptoms. Information regarding study characteristics and primary outcomes was collated. The Cochrane risk of bias scale was used to evaluate the quality of the studies included.

Results

A total of 1,454 citations were identified, 11 studies fulfilled the inclusion criteria (4 randomised control trials [RCTs] and 7 prospective studies). The key interventions studied were acupuncture, relaxation therapy, physical therapy, hydrogen-rich therapy, diet and nitric oxide synthetase.

Conclusion

Therapies with the potential for benefit in patients with bladder pain syndrome are dietary management, acupuncture and physical therapy. These findings were obtained from small studies and hence caution is advised. Robustly designed multicentre RCTs on these complementary therapies are needed to guide patients and clinicians.

Evaluation of Percutaneous Tibial Nerve Stimulation for Treatment of Refractory Painful Bladder Syndrome

OBJECTIVE

To evaluate the efficacy of intermittent percutaneous tibial nerve stimulation (PTNS) as a treatment modality for patients with refractory interstitial cystitis/bladder pain syndrome (IC/BPS).

PATIENTS AND METHODS

Twenty female patients with IC/BPS (mean symptom duration of 4.5 ± 2.4 years) each had a 30-minute session of PTNS per week for 12 successive weeks and the symptoms were assessed before, during, and after the treatment sessions by voiding diary, visual analog scale (VAS) for pain, interstitial cystitis symptom and problem indices (ICSI and ICPI), and global response assessment (GRA) scale. The scores of the previous questionnaires were evaluated at weeks 0, 6, and 12.

RESULTS

At week 0, the VAS, day time frequency, nocturia, and average voiding volume were 5.6 ± 1.1, 14.5 ± 4.0, 3.0 ± 0.9, and 131.8 ± 35.3 mL, respectively, meanwhile at week 12 these scores were 5.2 ± 1.5, 12.15 ± 3.7, 2.6 ± 0.7, and 141.0 ± 36.2, respectively. There was no statistically significant difference between the scores of the ICPI between weeks 0, 6, and 12 (P = .937). As regards the GRA score after the 12th session, 17 patients (85%) reported having no effect, 1 patient (5%) reported as having worse symptoms, and 2 patients (10%) reported having a mild good response.

CONCLUSION

Intermittent PTNS is not a satisfactory treatment for refractory IC/BPS. However, it is recommended to perform more studies with other treatment protocol (maybe closer sessions) to confirm these results.

Variations in the reporting of outcomes used in systematic reviews of treatment effectiveness research in bladder pain syndrome

This paper investigates the quality of outcomes reported in systematic reviews and randomised controlled trials (RCTs) of bladder pain syndrome and its relationship with study quality and journal impact factor. We searched until August 2013 the Cochrane Library, EMBASE, Medline, CINAHL, LILACS and SIGLE, without language restrictions. Quality of outcome reporting in systematic reviews and constituent RCTs was assessed using a 6-point scale. Overall study quality was assessed using the AMSTAR and Jadad scoring systems, and impact factor in the year of publication was noted. Spearman's rank correlation was calculated. There were 8 systematic reviews, with a total of 28 RCTs (1732 patients), reporting 5 outcomes using 19 different measurement scales. The outcomes reported in individual RCTs were urinary symptoms (100%), pain (64%), quality of life (39%), general wellbeing (36%) and bladder capacity (36%). The mean quality of outcomes reported was 1.63 (95% CI 0.29-2.96) for systematic reviews and 3.25 (95% CI 2.80-3.70) for RCTs. The quality of outcomes reported showed correlation with overall study quality (0.90, 95% CI 0.79-0.95, p<0.0001) but not with journal impact factor (0.07, 95% CI -0.31-0.43, p=0.35). Multivariable linear regression showed a relationship between quality of outcome reporting and study quality (β=0.05, p<0.0001), adjusting for effects of study type, impact factor and journal type. There is a need to generate consensus over a set of core outcomes in bladder pain syndrome using standardised reporting tools and to disseminate these through good publication practice.

New directions in the treatment of pelvic pain

SUMMARY The treatment of chronic pelvic pain in both females and males is a challenge for pain clinicians. Standard therapies are multimodal in nature with use of behavioral, medical and procedural therapeutics. In recent years, our understanding of the neurobiology of this disorder has improved and novel approaches have focused on neuromodulatory options, novel pharmacology and complementary/alternative medicine options. This review briefly examines newly employed therapeutic options, while restating currently utilized options. The current state-of-the-art treatment includes focal therapies for identified pathologies and empiric trials of other options for care when precise sources of the chronic pelvic pain are ill defined.