Transcutaneous tibial nerve stimulation for the treatment of bladder storage symptoms in people with multiple sclerosis: Protocol of a single-arm feasibility study

Development of a Sham Protocol to Investigate Transcutaneous Tibial Nerve Stimulation in Randomised, Sham-Controlled, Double-Blind Clinical Trials

Transcutaneous tibial nerve stimulation (TTNS) is a promising treatment for neurogenic lower urinary tract symptoms. However, the evidence is limited due to a general lack of randomised controlled trials (RCTs) and, also, inconsistency in the sham and blinding conditions. In the context of much-needed RCTs, we aimed to develop a suitable sham-control protocol for a clinical setting to maintain blinding but avoid meaningful stimulation of the tibial nerve. Three potential electrode positions (lateral malleolus/5th metatarsal/plantar calcaneus) and two electrode sizes (diameter: 2.5 cm/3.2 cm) were tested to determine which combination provided the optimal sham configuration for a TTNS approach, based on a visible motor response. Sixteen healthy volunteers underwent sensory and motor assessments for each sham configuration. Eight out of them came back for an extra TTNS visit. Sensory thresholds were present for all sham configurations, with linear regression models revealing a significant effect regarding electrode position (highest at plantar calcaneus) but not size. In addition, motor thresholds varied with the position-lowest for the 5th metatarsal. Only using this position and 3.2 cm electrodes attained a 100% response rate. Compared to TTNS, sensory and motor thresholds were generally higher for the sham configurations; meanwhile, perceived pain was only higher at the lateral malleolus. In conclusion, using the 5th metatarsal position and 3.2 cm electrodes proved to be the most suitable sham configuration. Implemented as a four-electrode setup with standardized procedures, this appears to be a suitable RCT protocol for maintaining blinding and controlling for nonspecific TTNS effects in a clinical setting.

Feasibility and acceptability of transcutaneous tibial nerve stimulation for the treatment of bladder storage symptoms among people with multiple sclerosis

Background

Neurogenic lower urinary tract dysfunction is an abnormality in the presence of underlying neurologic disease. A recent systematic review and meta-analysis demonstrated that storage phase symptoms are the predominant symptoms among people with multiple sclerosis (PwMS). Transcutaneous tibial nerve stimulation (TTNS) is a non-invasive treatment for bladder storage symptoms; however, the potential efficacy of stimulation among PwMS is based on a small number of studies with the absence of high-quality evidence. The aim of this study was to evaluate the feasibility, acceptability, and safety of TTNS in PwMS using an affordable transcutaneous electrical nerve stimulation (TENS) unit.

Methods

A total of 23 participants with MS enrolled in the study. The primary outcomes included recruitment/retention rate, completion of the outcomes and the intervention, adherence to the protocol, adverse events, and acceptability of the intervention. The primary outcomes were assessed using diaries and a satisfaction questionnaire. The secondary outcomes included changes in urinary symptoms and quality of life assessed using a set of validated outcome measures including a 3-day bladder diary, PPIUS, ICIQ-OAB, and KHQ at baseline and post-intervention.

Results

Twenty participants completed the study. Three participants (13.04%) withdrew. All 20 participants completed the 6-week intervention and all the outcome measures (100%), with no reported adverse events. Participants were satisfied and found the unit acceptable. Three-day bladder diary showed changes in urinary frequency from a daily median of 10 times to 8 times and daily median urgency changed from 6 times at baseline to 2 times post-intervention. PPIUS showed changes in daily median sever urgency from 3 points (IQR=4) to 1 point (IQR=1) post-intervention. ICIQ-OAB total scores changed from 8 points (IQR=2.25) to 4 points (IQR=2.5) post-intervention. Median and mean scores of KHQ showed a clinical meaningful change of QoL in part-two and part-three of the questionnaire.

Conclusions

TTNS is feasible, safe, and acceptable for PwMS. Changes of urinary symptoms scores and QoL post-intervention suggested improvements. Future implications need to consider the treatment protocol including frequency of treatment sessions, duration of treatment, and the electrical stimulation parameters as well as the outcome measures followed in the current study for the implementation of the future pilot RCT.

Trial registration

ClinicalTrials.gov NCT04528784. Registered on 27 August 2020. https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01120-1.

Posterior Tibial Nerve Stimulation for Overactive Bladder: Mechanism, Classification, and Management Outlines

Purpose of the Review. Posterior tibial nerve stimulation (PTNS) techniques have dramatically grown after approval to manage overactive bladder (OAB). The present review will focus on the most current data on PTNS types (percutaneous, transcutaneous, and implant) and their mechanism of action, safety, efficacy, advantages, drawbacks, limitation, and clinical applications. Recent Findings. The present review described the recent studies that addressed the tibial nerve stimulation role in OAB management. BlueWind RENOVA system, Bioness StimRouter, and eCoin are examples of emerging technologies that have evolved from interval sessions (percutaneous PTNS and transcutaneous PTNS) to continuous stimulation (implants). These can be efficiently managed at home by patients with minimum burden on the health system and fewer visits, especially in the COVID-19 pandemic. Summary. Our review shows that the tibial nerve stimulation advancements in OAB treatment have been rapidly increasing over the recent years. It is minimally invasive and effective, similar to sacral nerve stimulation (SNM), but less aggressive. Implantable PTNS has been promised in terms of efficacy, safety, and high acceptance rate. However, evidence is still limited to short-term trials, and tolerability, method, and drawbacks remain challenges.