Short-term clinical and manometric outcomes of percutaneous tibial nerve stimulation for faecal incontinence: a large single-centre series.

BACKGROUND: Faecal incontinence (FI) is common, with a significant impact on quality of life. Percutaneous tibial nerve stimulation (PTNS) is a therapy for FI; however, its role has recently been questioned. Here we report the short-term clinical and manometric outcomes in a large tertiary centre. METHODS: A retrospective review of a prospective PTNS database was performed, extracting patient-reported FI outcome measures including bowel diary, the St Marks's Incontinence Score (SMIS) and Manchester Health Questionnaire (MHQ). Successful treatment was > 50% improvement in symptoms, whilst a partial response was 25-50% improvement. High-resolution anorectal manometry (HRAM) results before and after PTNS were recorded. RESULTS: Data were available from 135 patients [119 (88%) females; median age: 60 years (range: 27-82years)]. Overall, patients reported a reduction in urge FI (2.5-1) and passive FI episodes (2-1.5; p < 0.05) alongside a reduction in SMIS (16.5-14) and MHQ (517.5-460.0; p < 0.001). Some 76 (56%) patients reported success, whilst a further 20 (15%) reported a partial response. There were statistically significant reductions in rectal balloon thresholds and an increase in incremental squeeze pressure; however, these changes were independent of treatment success. CONCLUSION: Patients report PTNS improves FI symptoms in the short term. Despite this improvement, changes in HRAM parameters were independent of this success. HRAM may be unable to measure the clinical effect of PTNS, or there remains the possibility of a placebo effect. Further work is required to define the role of PTNS in the treatment of FI.

The feasibility of the posterior tibial nerve-flexor hallucis brevis pathway applied in neuromuscular monitoring: a multicentric, controlled, and prospective clinical trial.

This study aimed to investigate the clinical viability of utilizing the flexor hallucis brevis as an alternative site for neuromuscular monitoring compared to the conventional adductor pollicis. Patients were recruited from three medical centers. Cis-atracurium was administered, and two monitors were employed independently to assess neuromuscular blockade of the adductor pollicis and the ipsilateral flexor hallucis brevis, following a train of four (TOF) pattern until TOF ratios exceeded 0.9 or until the conclusion of surgery. Statistical analysis revealed significant differences in onset time, duration of no-twitch response, spontaneous recovery time, and total monitoring time between the two sites, with mean differences of -53.54 s, -2.49, 3.22, and 5.89 min, respectively (P < 0.001).The posterior tibial nerve-flexor hallucis brevis pathway presents a promising alternative for neuromuscular monitoring during anesthesia maintenance. Further investigation is warranted to explore its utility in anesthesia induction and recovery. Trial registration: The trial was registered at www.chictr.org.cn (20/11/2018, ChiCTR1800019651).

Morphometric assessment of tibial nerve and its branches around the ankle.

It is essential to understand the considerable variations in bifurcation patterns of the tibial nerve (TN) and its peripheral nerves at the level of the tarsal tunnel to prevent iatrogenic nerve injury during surgical nerve release or nerve block. A total of 16 ankles of 8 human cadavers were dissected to investigate the branching patterns of the TN, using 2 imaginary lines passing through the tip of the medial malleolus (MM) as reference lines. Bifurcation patterns and detailed information on the relative locations of the medial plantar, lateral plantar, medial calcaneal, and inferior calcaneal nerves to the reference lines were recorded. The most common bifurcation pattern was Type 1 in 12 ankles (75%), followed by Type 2 in 2 ankles (13%). One medial calcaneal nerve (MCN) was seen in 11 (69%) specimens and 2 MCN branches were seen in 5 (31%) specimen. 88% of the MCN branches bifurcated from the TN, whereas 6% originated from both TN and lateral plantar nerve (LPN). At the level of the tip of the MM, 2 of 7 parameters showed statistically significant difference between both sexes (P < .05). There was a statistically significant difference between left and right ankles in 2 of 7 measurements (P < .05). Further morphometric analysis of the width, distance, and angle between the TN branches and the tip of MM showed a highly variable nature of the location of the peripheral nerve branches.

Transcutaneous tibial nerve stimulation in patients with multiple sclerosis and overactive bladder: a real-life clinical and urodynamic assessment.

AIMS: The aims of the present study were to assess the effectiveness of transcutaneous tibial nerve stimulation (TTNS) on overactive bladder (OAB) symptoms and on urodynamic parameters in patients with multiple sclerosis (PwMS) and to seek predictive factors of satisfaction. METHODS: All PwMS who performed 12-24 weeks of TTNS and who underwent urodynamic assessment before and after treatment between June 2020 and October 2022 were included retrospectively. Data collected were bladder diaries, symptoms assessed with Urinary Symptoms Profile (USP), and urodynamic parameters (bladder sensations, detrusor overactivity, and voiding phase). Patients with improvement rated as very good or good on Patient Global Impression of Improvement (PGI-I) score were considered as responders. RESULTS: Eighty-two patients were included (mean age: 47.1 ± 11.5 years, 67 (82%) were women). The mean USP OAB sub-score decreased from 7.7 ± 3.5 to 6.0 ± 3.4 (p < 0.0001). On bladder diaries, voided volumes, void frequency, and the proportion of micturition done at urgent need to void significantly improved with TTNS (p < 0.05). No significant change was found in urodynamic parameters. According to the PGI-I, 34 (42.5%) patients were good responders. The only parameter associated with higher satisfaction was the percentage of micturition done at urgent need to void before the initiation of the treatment (39.8% ± 30.5 in the responder group vs 25.1% ± 25.6 in the low/no responder group; p = 0.04). CONCLUSION: TTNS improves OAB symptoms in PwMS, without significant changes on urodynamics. A high rate of strong or urgent need to void in daily life was associated with higher satisfaction.

The Effectiveness of Indonesia's Seven - Step Return to Work Assessment on a Distal Tarsal Tunnel Syndrome : A Case Report Study.

Tarsal tunnel syndrome (TTS) is a nerve entrapment of the posterior tibial nerve. This uncommon condition frequently goes undiagnosed or misdiagnosed even though it interferes with the daily activities of workers. Here we discuss the return to work status of a 37-year-old male patient who manages a manufacturing plant. He was identified as having Tarsal Tunnel Syndrome as a result of a foot abnormality and improper shoe wear. He had moderate pes planus and underwent tarsal tunnel release on his right foot. What are the determinant factors in defining a patient's status for returning to work after a tarsal tunnel release? We conducted a literature review using PubMed, Science Direct, and Cochrane. The Indonesian Occupational Medicine Association used the seven-step return-to-work assessment as a protocol to avoid overlooking the process. Duration of symptoms, associated pathology, and the presence of structural foot problems or a space-occupying lesion are factors affecting outcome. Post-operative foot scores, including Maryland Foot Score (MFS), VAS, and Foot Function Index, can be used to evaluate patient outcomes. Early disability limitation and a thorough return-to-work assessment are needed.

Tibial nerve branching pattern and compatibility of branches for the deep fibular nerve.

PURPOSE: In individuals who develop drop foot due to nerve loss, several methods such as foot-leg orthosis, tendon transfer, and nerve grafting are used. Nerve transfer, on the other hand, has been explored in recent years. The purpose of this study was to look at the tibial nerve's branching pattern and the features of its branches in order to determine the suitability of the tibial nerve motor branches, particularly the plantaris muscle motor nerve, for deep fibular nerve transfer. METHODS: There were 36 fixed cadavers used. Tibial nerve motor branches were observed and measured, as were the lengths, distributions, and thicknesses of the common fibular nerve and its branches at the bifurcation region. RESULT: The motor branches of the tibial nerve that supply the soleus muscle, lateral head, and medial head of the gastrocnemius were studied, and three distinct forms of distribution were discovered. The motor branch of the gastrocnemius medial head was commonly observed as the first branch to divide, and it appeared as a single root. The nerve of the plantaris muscle was shown to be split from many origins. When the thickness and length of the motor branches measured were compared, the nerve of the soleus muscle was determined to be the most physically suited for neurotization. CONCLUSION: In today drop foot is very common. Traditional methods of treatment are insufficient. Nerve transfer is viewed as an application that can both improve patient outcomes and hasten the patient's return to society. The nerve of the soleus muscle was shown to be the best candidate for transfer in our investigation.

Reference values for nerve conduction studies of the peroneal, tibial, and sural nerve derived from a large population-based cohort: Associations with demographic and anthropometric characteristics-The Maastricht study.

INTRODUCTION/AIMS: Nerve conduction studies (NCSs) are widely used to support the clinical diagnosis of neuromuscular disorders. The aims of this study were to obtain reference values for peroneal, tibial, and sural NCSs and to examine the associations with demographic and anthropometric factors. METHODS: In 5099 participants (aged 40-79 years) without type 2 diabetes of The Maastricht Study, NCSs of peroneal, tibial, and sural nerves were performed. Values for compound muscle action potential (CMAP) and sensory nerve action potential amplitude, nerve conduction velocity (NCV), and distal latency were acquired. The association of age, sex, body mass index (BMI), and height with NCS values was determined using uni- and multivariate linear regression analyses. RESULTS: Detailed reference values are reported per decade for men and women. Significantly lower NCVs and longer distal latencies were observed in all nerves in older and taller individuals as well as in men. In these groups, amplitudes of the tibial and sural nerves were significantly lower, whereas a lower peroneal nerve CMAP was only significantly associated with age. BMI showed a multidirectional association. After correction for anthropometric factors in the multivariate analysis, the association between sex and NCS values was less straightforward. DISCUSSION: These values from a population-based dataset could be used as a reference for generating normative values. Our findings show the association of NCS values with anthropometric factors. In clinical practice, these factors can be considered when interpreting NCS values.

Utilization of the Rat Tibial Nerve Transection Model to Evaluate Cellular and Molecular Mechanisms Underpinning Denervation-Mediated Muscle Injury.

Peripheral nerve injury denervates muscle, resulting in muscle paralysis and atrophy. This is reversible if timely muscle reinnervation occurs. With delayed reinnervation, the muscle's reparative ability declines, and muscle-resident fibro-adipogenic progenitor cells (FAPs) proliferate and differentiate, inducing fibro-fatty muscle degradation and thereby physical disability. The mechanisms by which the peripheral nerve regulates FAPs expansion and differentiation are incompletely understood. Using the rat tibial neve transection model, we demonstrated an increased FAPs content and a changing FAPs phenotype, with an increased capacity for adipocyte and fibroblast differentiation, in gastrocnemius muscle post-denervation. The FAPs response was inhibited by immediate tibial nerve repair with muscle reinnervation via neuromuscular junctions (NMJs) and sensory organs (e.g., muscle spindles) or the sensory protection of muscle (where a pure sensory nerve is sutured to the distal tibial nerve stump) with reinnervation by muscle spindles alone. We found that both procedures reduced denervation-mediated increases in glial-cell-line-derived neurotrophic factor (GDNF) in muscle and that GDNF promoted FAPs adipogenic and fibrogenic differentiation in vitro. These results suggest that the peripheral nerve controls FAPs recruitment and differentiation via the modulation of muscle GDNF expression through NMJs and muscle spindles. GDNF can serve as a therapeutic target in the management of denervation-induced muscle injury.

Is percutaneous tibial nerve stimulation (PTNS) effective for fecal incontinence (FI) in adults compared with sham electrical stimulation? A meta-analysis.

BACKGROUND: Sacral nerve neuromodulation (SNM) has been considered the optimal second-line treatment for fecal incontinence (FI). However, SNM involves high cost and requires highly skilled operators. Percutaneous tibial nerve stimulation (PTNS) has emerged as an alternative treatment modality for FI, yielding varying clinical outcomes. We conducted this meta-analysis to evaluate the effectiveness and safety of PTNS compared to sham electrical stimulation for FI. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies from May 12, 2012 to May 12, 2022. RESULTS: Four randomized controlled studies were included in this review, involving a total of 439 adult patients with FI (300 in the PTNS group and 194 in the sham electrical stimulation group). Our meta-analysis revealed that PTNS demonstrated superior efficacy in reducing weekly episodes of FI compared to the control groups (MD - 1.6, 95% CI - 2.94 to - 0.26, p = 0.02, I2 = 30%). Furthermore, a greater proportion of patients in the PTNS group reported more than a 50% reduction in FI episodes per week (RR 0.73, 95% CI 0.57-0.94, p = 0.02, I2 = 6%). However, no significant differences were observed in any domains of the FI Quality of Life (QoL) and St Mark's incontinence scores (MD - 2.41, 95% CI - 5.1 to 0.27, p = 0.08, I2 = 67%). Importantly, no severe adverse events related to PTNS were reported in any of the participants. CONCLUSIONS: Our meta-analysis revealed that PTNS was more effective than sham stimulation in reducing FI episodes and led to a higher proportion of patients reporting more than a 50% reduction in weekly FI episodes.

Who Progresses to Third-Line Therapies for Overactive Bladder? Trends From the AQUA Registry.

INTRODUCTION: Overactive bladder (OAB) patients who do not achieve satisfactory results with second-line OAB medications should be offered third-line therapies (percutaneous tibial nerve stimulation, sacral neuromodulation, onabotulinumtoxinA bladder injection [BTX-A]). We aimed to determine which clinical factors affect progression from second- to third-line OAB therapy. METHODS: Between 2014 and 2020, the AUA Quality Registry was queried for adult patients with idiopathic OAB. For the primary outcome, patient and provider factors associated with increased odds of progression from second- to third-line therapy were assessed. Secondary outcomes included median time for progression to third-line therapy and third-line therapy utilization across subgroups. RESULTS: A total of 641,122 patients met inclusion criteria and were included in analysis. Of these, only 7487 (1.2%) received third-line therapy after receiving second-line therapy. On multivariate analysis, patients aged 65 to 79, women, White race, history of dual anticholinergic and ß3 agonist therapy, metropolitan area, government insurance, and single specialty practice had the greatest odds of progressing to third-line therapy. Black and Asian race, male gender, and rural setting had lower odds of progressing to third-line therapy. BTX-A was the most common therapy overall (40% BTX-A, 32% sacral neuromodulation, 28% percutaneous tibial nerve stimulation). The median time of progression from second- to third-line therapy was 15.4 months (IQR 5.9, 32.4). Patients < 50 years old and women progressed fastest to third-line therapy. CONCLUSIONS: Very few patients received third-line therapies, and the time to progression from second- to third-line therapies is > 1 year. The study findings highlight a potential need to improve third-line therapy implementation.

Mechanism of Action of Tibial Nerve Stimulation in the Treatment of Lower Urinary Tract Dysfunction.

BACKGROUND AND OBJECTIVE: Tibial nerve stimulation (TNS) has long been used to effectively treat lower urinary tract dysfunction (LUTD). Although numerous studies have concentrated on TNS, its mechanism of action remains elusive. This review aimed to concentrate on the mechanism of action of TNS against LUTD. MATERIALS AND METHODS: A literature search was performed in PubMed on October 31, 2022. In this study, we introduced the application of TNS for LUTD, summarized different methods used in exploring the mechanism of TNS, and discussed the next direction to investigate the mechanism of TNS. RESULTS AND CONCLUSIONS: In this review, 97 studies, including clinical studies, animal experiments, and reviews, were used. TNS is an effective treatment for LUTD. The study of its mechanisms primarily concentrated on the central nervous system, tibial nerve pathway, receptors, and TNS frequency. More advanced equipment will be used in human experiments to investigate the central mechanism, and diverse animal experiments will be performed to explore the peripheral mechanism and parameters of TNS in the future.

Peripheral Nerve Stimulation With a High-Frequency Electromagnetic Coupled Powered Implanted Receiver at the Posterior Tibial Nerve for the Treatment of Chronic Pain in the Foot.

INTRODUCTION: Peripheral neuropathy has several causes, with diabetes being the most common. Conservative management may fail to control pain. Our study aimed at evaluating the use of peripheral nerve stimulation of the posterior tibial nerve for treating peripheral neuropathy. MATERIALS AND METHODS: This was an observational study of 15 patients who received peripheral nerve stimulation at the posterior tibial nerve to treat peripheral neuropathy. Outcomes measured were improvement of pain scores and Patient Global Impression of Change (PGIC) at 12 months compared with before the implant. RESULTS: Mean pain scores with the verbal rating scale were 3 ± 1.8 at >12 months compared with 8.6 ± 1.2 at baseline, a reduction of 65% (p < 0.001). Median satisfaction with the PGIC at >12 months was 7 of 7, with most subjects reporting a 6 (better) or a 7 (a great deal better). CONCLUSION: Peripheral nerve stimulation of the posterior tibial nerve can be a safe and effective modality for treating chronic pain symptoms related to peripheral neuropathy of the foot.

What Is in the Pipeline on Investigational Neuromodulation Techniques for Lower Urinary Tract Dysfunction: A Narrative Review.

OBJECTIVES: Overactive bladder (OAB) affects millions of patients worldwide. Its treatment is challenging but improves the patient's quality of life. Besides standard techniques for neuromodulation (sacral and pudendal neuromodulation and posterior tibial nerve stimulation), several new techniques have been investigated to treat symptoms of refractory OAB. The purpose of the present review is to outline the state of the art of new neuromodulation techniques for lower urinary tract dysfunction (LUTD). MATERIALS AND METHODS: In March 2023, a comprehensive MEDLINE, EMBASE, and Scopus search was carried out (keywords: LUTD, new technologies, neuromodulation, LUTS, OAB, painful bladder syndromes, etc). Articles were included according to inclusion (randomized controlled trials, prospective trials, large retrospective studies) and exclusion (case reports, outcomes not clearly expressed in full text, animal studies) criteria. The reference lists of the included studies also were scanned. Both adult and pediatric populations were included, in addition to both neurogenic and nonneurogenic OAB. A narrative review was then performed. RESULTS: Peroneal neuromodulation, transcutaneous electrical nerve stimulation, magnetic nerve stimulation, and parasacral transcutaneous neuromodulation are the most studied investigative techniques and were shown to yield promising results in treating OAB symptoms. Most studies showed promising results even in the complex scenarios of patients with OAB refractory to standard treatments. Comparing investigational techniques with standard of care and their respective clinical outcomes and safety profiles, and confronting their pros and cons, we reasonably believe that once such treatment modalities are further developed, they could play a role in the OAB treatment algorithm. CONCLUSIONS: Although the described neuromodulation techniques are being intensely studied, the available results are not yet sufficient for any guidelines to recommend their use.

Comparison of acute responses in spinal excitability between older and young people after neuromuscular electrical stimulation.

PURPOSE: This study aims at comparing acute responses in spinal excitability, as measured by H-reflex, between older and young individuals, following a single session of NMES superimposed onto voluntary isometric contractions of the ankle plantar-flexor muscles (NMES+), with respect to passive NMES (pNMES) and voluntary isometric contractions only (ISO). METHODS: Thirty-two volunteers, 16 older (OLDER) and 16 young (YOUNG), were asked to sustain a constant force at 20% of maximal voluntary isometric contraction (MVIC) of the ankle plantar-flexor muscles in the dominant limb during each of the 3 conditions (NMES+ , pNMES and ISO). Fifteen repetitions of 6 s were performed, with a resting interval of 6 s between repetitions. Before and after each condition, soleus H-reflexes were elicited by percutaneous electrical stimulation of the posterior tibial nerve and H-reflex amplitudes recorded by surface EMG. RESULTS: In OLDER, H-reflex amplitude did not change following any experimental condition (ISO: p = 0.203; pNMES: p = 0.542; NMES+: p = 0.431) compared to baseline. On the contrary, in YOUNG, H-reflex amplitudes significantly increased (p < 0.000) and decreased (p = 0.001) following NMES+ and pNMES, respectively, while there was no significant change in reflex responses following ISO (p = 0.772). CONCLUSION: The lack of change in H-reflex responses following either NMES+ or pNMES might reflect a reduced ability of older people in modulating spinal excitability after the conditions. Specifically, an age-related alteration in controlling mechanisms at presynaptic level was suggested.

Pilot Study of a Novel At-Home Posterior Tibial Nerve System for Overactive Bladder Syndrome.

IMPORTANCE: Urgency urinary incontinence and overactive bladder are common conditions. Third-line therapies are often underutilized because of either being too invasive or being burdensome for the patient. OBJECTIVE: We aimed to determine the efficacy and acceptability of a noninvasive, home-based posterior tibial nerve treatment system for the treatment of overactive bladder syndrome. STUDY DESIGN: In this pilot study, 10 postmenopausal women with urgency urinary incontinence were given the SoleStim System for home-based posterior tibial nerve stimulation. Symptoms at baseline and completion of the 8-week study were determined by 3-day voiding diary and quality-of-life questionnaire (Overactive Bladder Questionnaire) to assess for reduction in incontinence episodes. RESULTS: All patients were 100% adherent to the SoleStim System application over the 8-week period and reported statistically significant reductions in the mean number of voids (-16.3%, P = 0.022), urgency episodes (-31.2%, P = 0.02), and urgency urinary incontinence episodes (-31.4%, P = 0.045). Forty percent of participants reported a decrease of ≥50% in their urgency urinary incontinence episodes. SoleStim was scored a value of 1.8 ± 2.0 (mean ± SD) on a 10-point usability scale, indicating that it was highly acceptable from an ease-of-use perspective. No adverse events were reported. CONCLUSIONS: The SoleStim System improved key overactive bladder (frequency, urgency, and urgency urinary incontinence episodes) and quality-of-life metrics. The results from this pilot study suggest that the SoleStim System may be a safe, effective, and highly acceptable at-home overactive bladder therapy.

Immediate and Long-Term Effects of Tibial Nerve Stimulation on the Sexual Behavior of Female Rats.

OBJECTIVES: There are limited treatment options for female sexual dysfunction (FSD). Percutaneous tibial nerve stimulation (PTNS) has shown improvements in FSD symptoms in neuromodulation clinical studies, but the direct effects on sexual function are not understood. This study evaluated the immediate and long-term effects of PTNS on sexual motivation and receptivity in a rat model of menopausal women. Our primary hypothesis was that long-term PTNS would yield greater changes in sexual behavior than short-term stimulation. MATERIALS AND METHODS: In two experiments, after receiving treatment, we placed ovariectomized female rats in an operant chamber in which the female controls access to a male by nose poking. We used five treatment conditions, which were with or without PTNS and no, partial, or full hormone priming. In experiment 1, we rotated rats through each condition twice with behavioral testing immediately following treatment for ten weeks. In experiment 2, we committed rats to one condition for six weeks and tracked sexual behavior over time. We quantified sexual motivation and sexual receptivity with standard measures. RESULTS: No primary comparisons were significant in this study. In experiment 1, we observed increased sexual motivation but not receptivity immediately following PTNS with partial hormone priming, as compared with priming without PTNS (linear mixed effect models; initial latency [p = 0.34], inter-interval latency [p = 0.77], nose poke frequency [p = 0.084]; eight rats). In experiment 2, we observed trends of increased sexual receptivity (linear correlation for weekly group means; mounts [p = 0.094 for trendline], intromissions [p = 0.073], lordosis quotient [p = 0.58], percent time spent with a male [p = 0.39], decreased percent time alone [p = 0.024]; four rats per condition), and some sexual motivation metrics (linear correlation for weekly group means; nose pokes per interval [p = 0.050], nose poke frequency [p = 0.039], decreased initial latency [p = 0.11]; four rats per condition) when PTNS was applied long-term with partial hormone priming, as compared with hormone-primed rats without stimulation. CONCLUSIONS: PTNS combined with hormone priming shows potential for increasing sexual motivation in the short-term and sexual receptivity in the long-term in rats. Further studies are needed to examine variability in rat behavior and to investigate PTNS as a treatment for FSD in menopausal women.

Response to tibial and sacral nerve modulation in overactive bladder: Is there any correlation?

OBJECTIVES: To assess the correlation between the response to transcutaneous tibial nerve stimulation (TTNS) and subsequent response to sacral nerve modulation (SNM) to treat overactive bladder (OAB). MATERIALS AND METHODS: All patients who consecutively received TTNS followed by a two-stage SNM between January 2016 and June 2022 to treat OAB in two university hospital centers were included. The response to each therapy was evaluated with success defined by a 50% or greater improvement in one or more bothersome urinary symptoms from baseline. The primary endpoint was the statistical relationship between the response to TTNS and the response to SNM, assessed by logistic regression. Secondary endpoints were the statistical relationship between the response to TTNS and the response to SNM when controlling for gender, age (<57 years vs. >57 years), presence of an underlying neurological disease, and presence of DO, adding the factor and interaction to the previous regression model. RESULTS: Among the 92 patients enrolled in the study, 68 of them were women (73.9%), and the median age was 57.0 [41.0-69.0] years. The success was reported in 22 patients (23.9%) under TTNS and 66 patients (71.7%) during the SNM test phase. There was no statistical correlation between response to TTNS and response to SNM in the overall population (confidence interval: 95% [0.48-4.47], p = 0.51). Similarly, there was no statistical correlation when controlling for age <57 years or ≥57 years, with p = 1.0 and p = 0.69, respectively. No statistical study could be conducted for the other subpopulations due to small sample sizes. CONCLUSION: The response to TTNS does not predict the response to SNM in the treatment of OAB. TTNS and SNM should be considered as separate therapies, and the decision-making process for OAB treatment should take this into account.

Identification of brain functional connectivity during acute transcutaneous tibial nerve stimulation: A 3T fMRI study.

OBJECTIVES: A feasibility proof-of-concept study was conducted to assess the effects of acute tibial nerve stimulation (TNS) on the central nervous system in healthy volunteers using functional magnetic resonance imaging (fMRI). MATERIALS AND METHODS: Fourteen healthy volunteers were included in a prospective, single-site study conducted on a clinical 3T MRI scanner. Four scans of functional MRI, each lasting 6 min, were acquired: two resting-state fMRI scans (prior and following the TNS intervention) and in-between two fMRI scans, both consisting of alternating rest periods and noninvasive acute transcutaneous TNS (TTNS). Whole brain seed-based functional connectivity (FC) correlation analysis was performed comparing TTNS stimulation with rest periods. Cluster-level familywise error (FWE) corrected p and a minimal cluster size of 200 voxels were used to explore FC patterns. RESULTS: Increased FC is reported between inferior frontal gyrus, posterior cingulate gyrus, and middle temporal gyrus with the precuneus as central receiving node. In addition, decreased FC in the cerebellum, hippocampus, and parahippocampal areas was observed. CONCLUSIONS: Altered FC is reported in areas which have been described to be also involved in lower urinary tract control. Although conducted with healthy controls, the assumption that the underlying therapeutic effect of TNS involves the central nervous system is supported and has to be further examined in patients with incomplete spinal cord injury.