The importance of electrical parameters on transcutaneous tibial nerve stimulation for overactive bladder syndrome: a systematic review and meta-analysis.

INTRODUCTION

Overactive Bladder Syndrome (OAB) is common and distressing for older people. Transcutaneous Tibial Nerve Stimulation (TTNS) is a potential treatment when others have failed. Different electrical parameters-electrical frequency, intensity, pulse width-are used. We investigated their effect on urinary incontinence, urgency, frequency and nocturia.

METHODS

We searched MEDLINE, EMBASE and AMED to March 2025 for studies comparing TTNS to control/sham in adults with OAB in clinical/home settings. Two reviewers independently screened papers, extracted data and assessed risk of bias (using RoB2). We summarised studies narratively and used the GRADE framework. We meta-analysed RCTs (random-effects), grouping by electrical parameters. PROSPERO registration CRD42024490465.

RESULTS

We included 42 papers (13 RCTs), involving 2715 participants (972 in RCTs). Nearly half studies (47.6%) included people aged > = 60. TTNS protocols varied: electrical frequency 10/20 Hz; intensity set with sensory or motor threshold; pulse width mostly 200 microseconds. No serious adverse effects were reported, only mild pain/discomfort. TTNS at 10 Hz improved incontinence episodes (MD = -1.24, 95%CI -2.09 to -0.39, n = 255, N = 3). TTNS with motor threshold improved urgency (MD = -1.44, 95%CI -2.69 to -0.19, n = 193, N = 4) and nocturia (MD = -1.14, 95%CI -1.93 to -0.34, n = 153, N = 3). Risk of bias was low.

CONCLUSIONS

TTNS is a safe option to treat OAB. Electrical parameters may impact effectiveness (in favour of 10 Hz, motor threshold). Certainty is reduced due to the small number of studies and participants. Future studies should include different electrical parameters to clarify their impact, particularly with older people and to allow standardisation of future treatment and effect on specific symptoms.