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.

Anatomical Exploration of the KI1 Acupoint: Implications for Medial and Lateral Plantar Nerve Stimulation.

Background and Objectives: This study aims to identify the precise anatomical location and therapeutic mechanisms of the KI1 acupoint (Yongquan) in relation to foot muscles and nerves, known for treating neurological disorders and pain. Materials and Methods: Dissection of six cadavers at Chungnam National University College of Medicine examined KI1's relation to the foot's four-layer structure. Results: The KI1 acupoint was located in the superficial and deep layers of the plantar foot, adjacent to significant nerves like the medial and lateral plantar nerves. Differences in the acupoint's exact location between genders were noted, reflecting variances in foot morphology. KI1 acupuncture was found to stimulate the muscle spindles and nerve fibers essential for balance and bipedal locomotion. This stimulation may enhance sensory feedback, potentially improving cognitive functions and balance control. Conclusions: This anatomical insight into KI1 acupuncture underpins its potential in neurological therapies and pain management.

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.

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.

Efficacy and safety of tibial nerve stimulation using a wearable device for overactive bladder.

OBJECTIVE: To evaluate the efficacy and safety of a wearable, smartphone-controlled, rechargeable transcutaneous tibial nerve stimulation (TTNS) device in patients with overactive bladder (OAB). PATIENTS AND METHODS: This multicentre, prospective, single-blind, randomised clinical trial included eligible patients with OAB symptoms who were randomly assigned to the stimulation group or sham group. The primary efficacy outcome was change from baseline in voiding frequency/24 h after 4 weeks of treatment. The secondary efficacy outcomes included changes in bladder diary outcomes (urgency score/void, nocturia episodes/day, micturition volume/void, and incontinence episodes/day), questionnaires on Overactive Bladder Symptom Score (OABSS), Patient Perception of Bladder Condition (PPBC), and American Urological Association Symptom Index Quality of Life Score (AUA-SI-QoL) at baseline and after 4 weeks of treatment. Device-related adverse events (AEs) were also evaluated. RESULTS: In the full analysis set (FAS), the mean (sd) change of voiding frequency/24 h in the stimulation group and sham group at 4 weeks were -3.5 (2.9) and -0.6 (2.4), respectively (P < 0.01). Similar results were obtained in the per-protocol set (PPS): -3.5 (2.9) vs -0.4 (2.3) (P < 0.01). In the FAS and PPS, micturition volume/void significantly improved at 4 weeks (P = 0.01 and P = 0.02). PPBC improvement almost reached significance in the FAS (P = 0.05), while it was significant in the PPS (P = 0.02). In the FAS and PPS, AUA-SI-QoL significantly improved at 4 weeks in the two groups (P < 0.01 and P < 0.01), whereas there were no significant differences in urgency score/void, nocturia episodes/day or OABSS between the groups. Also, no device-related serious AEs were reported. CONCLUSIONS: The non-invasive neuromodulation technique using the novel ambulatory TTNS device is effective and safe for treating OAB. Its convenience and easy maintenance make it a new potential home-based treatment modality. Future studies are warranted to confirm its longer-term efficacy.

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.

Adaptive gait responses to varying weight-bearing conditions: Inferences from gait dynamics and H-reflex magnitude.

This study investigates the effects of varying loading conditions on excitability in neural pathways and gait dynamics. We focussed on evaluating the magnitude of the Hoffman reflex (H-reflex), a neurophysiological measure representing the capability to activate motor neurons and the timing and placement of the foot during walking. We hypothesized that weight manipulation would alter H-reflex magnitude, footfall and lower body kinematics. Twenty healthy participants were recruited and subjected to various weight-loading conditions. The H-reflex, evoked by stimulating the tibial nerve, was assessed from the dominant leg during walking. Gait was evaluated under five conditions: body weight, 20% and 40% additional body weight, and 20% and 40% reduced body weight (via a harness). Participants walked barefoot on a treadmill under each condition, and the timing of electrical stimulation was set during the stance phase shortly after the heel strike. Results show that different weight-loading conditions significantly impact the timing and placement of the foot and gait stability. Weight reduction led to a 25% decrease in double limb support time and an 11% narrowing of step width, while weight addition resulted in an increase of 9% in step width compared to body weight condition. Furthermore, swing time variability was higher for both the extreme weight conditions, while the H-reflex reduced to about 45% between the extreme conditions. Finally, the H-reflex showed significant main effects on variability of both stance and swing phases, indicating that muscle-motor excitability might serve as feedback for enhanced regulation of gait dynamics under challenging conditions.

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.

Shifts in patient preference of third-line overactive bladder therapy after introduction of the implantable tibial nerve stimulator.

INTRODUCTION: Third-line therapies for overactive bladder (OAB) that are currently recommended include intravesical Onabotulinumtoxin-A injections (BTX-A), percutaneous tibial nerve stimulation (PTNS), and sacral neuromodulation (SNM). The implantable tibial nerve stimulator (ITNS) is a novel therapy that is now available to patients with OAB. OBJECTIVE: The objective of this study was to analyze shifts in patient preference of third-line therapies for OAB after introducing ITNS as an option among the previously established therapies for non-neurogenic OAB. METHODS: A survey was designed and distributed via SurveyMonkey to the platform's audience of U.S. adults of age 18 and older. Screening questions were asked to include only subjects who reported symptoms of OAB. Descriptions of current AUA/SUFU guideline-approved third-line therapies (BTX-A, PTNS, and SNM) were provided, and participants were asked to rank these therapies in order of preference (stage A). Subsequently, ITNS was introduced with a description, and participants were then asked to rank their preferences amongst current guideline-approved therapies and ITNS (stage B). Absolute and relative changes in therapy preferences between stage A and stage B were calculated. Associations between ultimate therapy choice in stage B and participant characteristics were analyzed. RESULTS: A total of 485 participants completed the survey (62.5% female). The mean age was 49.1 ± 36.5 years (SD). The most common OAB symptoms reported were urgency urinary incontinence (UUI) (73.0%) and urinary urgency (68.0%). 29.2% of patients had tried medication for OAB in the past, and 8.0%-10.3% of patients were previously treated with a third-line therapy for OAB. In stage A, participants ranked their first choice of third-line therapy as follows: 28% BTX-A, 27% PTNS, and 13.8% SNM. 26.6% of participants chose no therapy, and 4.5% chose all three equally. In stage B, participants ranked their first choice as follows: 27.6% BTX-A, 19.2% PTNS, 7.8% SNM, and 19.2% ITNS. 21.9% of participants chose no therapy and 4.3% chose all four equally as their first choice. There were both absolute and relative declines in proportions of patients interested in BTX-A, SNM, and PTNS as their first choice of third-line therapy with the introduction of ITNS. Patients originally interested in PTNS in stage A had the greatest absolute change after the introduction of ITNS with 7.8% of participants opting for ITNS in stage B. Those interested in SNM in stage A had the largest relative change in interest, with 43.5% of those originally interested in SNM opting for ITNS in stage B. Finally, with the introduction of ITNS, the number of participants initially not interested in any third-line therapy declined by an absolute change of 4.7% and relative change of 17.6%. Participants experiencing concurrent stress urinary incontinence (SUI) symptoms were more likely to choose a current guideline-approved third-line therapy than ITNS or no therapy at all (p = 0.047). Those who had prior experience with third-line therapies were more likely to choose a third-line therapy other than ITNS as their ultimate choice of therapy in stage B. Of those who had chosen a guideline-approved third-line therapy in stage B (not ITNS), 13.6% had prior experience with BTX-A, 14.7% with PTNS, and 32 (11.2%) with SNM (p < 0.001, p < 0.001, p = 0.009, respectively). CONCLUSION: From our study, it appears that ITNS may attract a subset of patients who would not have otherwise pursued current guideline-approved third-line therapies for OAB. When patients are provided with descriptions of third-line OAB therapies including ITNS as an option, ITNS appears to compete with SNM and PTNS. It is possible that ITNS will provide patients with a different phenotype of neuromodulation therapy that can appeal to a niche OAB population. Given that ITNS devices have been introduced relatively recently to the market, their application will largely depend on cost and payer coverage, provider bias, and patient comorbidities. Further study is needed to understand how these factors interact with and influence patient preference of advanced OAB therapy to understand which patients will most benefit from this treatment modality.

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.

Soleus H-reflex amplitude modulation during walking remains physiological during transspinal stimulation in humans.

The soleus H-reflex modulation pattern was investigated during stepping following transspinal stimulation over the thoracolumbar region at 15, 30, and 50 Hz with 10 kHz carry-over frequency above and below the paresthesia threshold. The soleus H-reflex was elicited by posterior tibial nerve stimulation with a single 1 ms pulse at an intensity that the M-wave amplitudes ranged from 0 to 15% of the maximal M-wave evoked 80 ms after the test stimulus, and the soleus H-reflex was half the size of the maximal H-reflex evoked on the ascending portion of the recruitment curve. During treadmill walking, the soleus H-reflex was elicited every 2 or 3 steps, and stimuli were randomly dispersed across the step cycle which was divided in 16 equal bins. For each subject and condition, the soleus M-wave and H-reflex were normalized to the maximal M-wave. The soleus background electromyographic (EMG) activity was estimated as the linear envelope for 50 ms duration starting at 100 ms before posterior tibial nerve stimulation for each bin. The gain was determined as the slope of the relationship between the soleus H-reflex and the soleus background EMG activity. The soleus H-reflex phase-dependent amplitude modulation remained unaltered during transspinal stimulation, regardless frequency, or intensity. Similarly, the H-reflex slope and intercept remained the same for all transspinal stimulation conditions tested. Locomotor EMG activity was increased in knee extensor muscles during transspinal stimulation at 30 and 50 Hz throughout the step cycle while no effects were observed in flexor muscles. These findings suggest that transspinal stimulation above and below the paresthesia threshold at 15, 30, and 50 Hz does not block or impair spinal integration of proprioceptive inputs and increases activity of thigh muscles that affect both hip and knee joint movement. Transspinal stimulation may serve as a neurorecovery strategy to augment standing or walking ability in upper motoneuron lesions.

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.

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.

Effects of Transcutaneous Tibial Nerve Stimulation in Women Refractory to and Never Used Pharmacological Agents for Idiopathic Overactive Bladder.

INTRODUCTION AND HYPOTHESIS: The aim of this study is to compare the effectiveness of transcutaneous tibial nerve stimulation (TTNS) on quality of life (QoL) and clinical parameters related to incontinence in pharmacological agents (PhAs) naive and refractory women with idiopathic overactive bladder (iOAB). METHODS: In this prospective nonrandomized clinical trial, women with resistance to PhAs were included in the first group (n=21), PhA-naive women were included in the second group (n=21). TTNS was performed 2 days a week, a total of 12 sessions for 6 weeks. Every session lasted 30 min. Women were evaluated for the severity of incontinence (Pad test), 3-day voiding diary (voiding frequency, nocturia, incontinence episodes, and number of pads), symptom severity (Overactive Bladder Questionnaire-V8), quality of life (Incontinence Impact Questionnaire-7), treatment satisfaction, positive response, and cure-improvement rates. RESULTS: A statistically significant improvement was found in all parameters for each group at the 6th week compared with the baseline values (p<0.05). It was found that the severity of incontinence, incontinence episodes, symptom severity, treatment satisfaction, and QoL parameters were significantly improved in PhA-naive group compared with the PhA-resistant group at the 6th week (p<0.05). There were no statistically significant differences in the frequency of voiding, nocturia, and number of pads between the two groups (p>0.05). Positive response rates, the primary outcome measure, were statistically significantly higher in the PhA-naive group than in the PhA-resistant group. CONCLUSIONS: Although TTNS is more effective in PhA-naive women with iOAB, it appears to be an effective therapy that can also be used in the management of PhA-resistant women with iOAB.

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.

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.

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.