Pretibial TENS for Pain and Anxiety During Intravesical OnabotulinumtoxinA Injection

The Effect of Pretibial Transcutaneous Electrical Nerve Stimulation (TENS) on Pain and Anxiety During Intravesical OnabotulinumtoxinA Injection: A Double-Blind, Randomized, Placebo-Controlled Trial

Overactive bladder is a common condition that causes a frequent, urgent need to urinate and can significantly reduce quality of life. When other treatments do not work well enough, doctors can inject a medication called onabotulinumtoxinA (a form of botulinum toxin) into the bladder wall. This procedure is often done in the office and is effective, but it can cause pain and anxiety during the injection.

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive, drug-free method that uses mild electrical pulses delivered through pads placed on the skin. It is thought to reduce the sensation of pain and is already used to help with discomfort during some office procedures.

The purpose of this study is to find out whether applying TENS to the front of the lower legs (the pretibial area) reduces pain and anxiety in patients undergoing an intravesical onabotulinumtoxinA injection. Participants will be randomly assigned to one of two groups. In one group, the TENS device will be turned on (active). In the other group, the pads will be placed in the same location but the device will not be turned on (placebo). Neither the patient nor the doctor performing the assessment will know which group the patient is in.

Pain will be measured during the procedure using a visual analog scale. Anxiety will be measured before the procedure using a standard questionnaire, and patient satisfaction will be measured afterward. The study aims to enroll 68 participants in total.

Study Overview

• Status: Not yet recruiting
• Conditions: Anxiety; Overactive Bladder (OAB); Procedural Pain Relief; Botulinum Toxin Injection
• Intervention / Treatment: Device: Active Pretibial TENS; Device: Sham Pretibial TENS

Detailed Description

Background: Overactive bladder (OAB) is a chronic urological condition that substantially impairs quality of life, and intravesical onabotulinumtoxinA (BTX-A) injection is an effective treatment option. Although performing this procedure in an office setting reduces hospital and operating room costs, the pain and anxiety experienced during the procedure can negatively affect patient comfort. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive, non-pharmacological, and safe analgesic method believed to reduce pain perception through the gate control mechanism. Prior work has reported clinically meaningful reductions in pain scores when active TENS is applied during intravesical BTX-A injection; however, the effect of TENS applied specifically to the pretibial region during this procedure has not been previously investigated.

Objectives: The primary objective is to evaluate the effect of pretibial TENS on pain during office-based intravesical BTX-A injection, assessed using a Visual Analog Scale (VAS). Secondary objectives are to examine the relationship between pre-procedure anxiety level (measured with the Spielberger State-Trait Anxiety Inventory, STAI) and the pain experience, and to measure patient satisfaction using a 0-10 Likert scale.

Design: This is a randomized, double-blind, placebo-controlled trial. Participants will be randomized 1:1 using a sealed-envelope method. Envelopes will be prepared by an independent researcher not involved in conducting the study. Patients will be blinded to whether the device is active or inactive during the procedure, and blinding of the outcome assessment will be maintained.

Groups:

• Active group: TENS pads applied bilaterally to the pretibial region with the device operating in active mode.
• Control group: TENS pads applied to the same anatomical region with the device not activated (placebo).

In both groups, the intravesical BTX-A injection will be performed according to the standard routine clinical protocol without any modification.

Measurements will be collected in the following order as part of the patient's routine clinical visit:

• Before the procedure: the patient completes the Spielberger State-Trait Anxiety Inventory (STAI).
• During the procedure: pain is assessed by the performing physician using a VAS (0-10; 0 = no pain, 10 = unbearable pain).
• After the procedure: patient satisfaction is assessed using a 0-10 Likert scale.

Sample size: Based on a power analysis assuming an effect size (Cohen's d) of 0.7, a significance level (alpha) of 0.05, and power (1-beta) of 0.80, 34 participants per group were required, for a total sample size of 68 participants.

Statistical analysis: Continuous variables will be compared using the Student t-test or the Mann-Whitney U test, as appropriate. Categorical variables will be analyzed using the chi-square test. The relationship between STAI and VAS scores will be assessed using Spearman correlation. A p-value < 0.05 will be considered statistically significant.

• Study Type: Interventional
• Enrollment (Estimated): 68
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Veysel Sezgin; Phone Number: +905513895655; Email: veyselsezgin1@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of overactive bladder (OAB) with an indication for intravesical onabotulinumtoxinA (BTX-A) treatment
• No previous history of TENS application
• Age 18 years or older
• Provision of written informed consent

Exclusion Criteria:

• Presence of a cardiac pacemaker or any implanted neuromodulator device
• Impaired skin integrity in the pretibial region or peripheral neuropathy
• Pregnancy
• Coagulopathy that contraindicates the procedure, or active urinary tract infection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active TENS; TENS pads are applied bilaterally to the pretibial region and the device is operated in active mode during the intravesical onabotulinumtoxinA injection. The standard intravesical BTX-A injection is performed according to routine clinical protocol.	Device: Active Pretibial TENS; Transcutaneous electrical nerve stimulation delivered through pads placed bilaterally on the pretibial region, with the device turned on (active stimulation) during the intravesical onabotulinumtoxinA injection.
Placebo Comparator: Placebo TENS (Sham); TENS pads are applied to the same pretibial anatomical region but the device is not activated (sham). The standard intravesical BTX-A injection is performed according to routine clinical protocol, identical to the active group.	Device: Sham Pretibial TENS; Transcutaneous electrical nerve stimulation pads placed bilaterally on the pretibial region in an identical manner, but with the device not activated (no electrical stimulation delivered), during the intravesical onabotulinumtoxinA injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Procedural Pain Score (Visual Analog Scale, VAS)	Pain experienced during the intravesical onabotulinumtoxinA injection, assessed by the physician using a Visual Analog Scale ranging from 0 to 10 cm (0 = no pain, 10 = unbearable pain). Higher scores indicate greater pain. Mean VAS scores will be compared between the active TENS group and the placebo (sham) TENS group.	During the intravesical onabotulinumtoxinA injection procedure (single assessment at the time of the procedure)
Patient Satisfaction (0-10 Likert Scale)	Patient satisfaction with the procedure, assessed after the injection using a 0-10 Likert scale. Higher scores indicate greater satisfaction. Mean satisfaction scores will be compared between the active TENS group and the placebo (sham) TENS group.	Immediately after the intravesical onabotulinumtoxinA injection procedure (single assessment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pre-procedure Anxiety Level (State-Trait Anxiety Inventory, STAI)	Anxiety level measured before the procedure using the Spielberger State-Trait Anxiety Inventory (STAI). The relationship between the pre-procedure STAI score and the intraprocedural VAS pain score will be assessed. Higher STAI scores indicate greater anxiety.	Immediately before the intravesical onabotulinumtoxinA injection procedure (single assessment)

Collaborators and Investigators

• Sponsor: Başakşehir Çam & Sakura City Hospital

Publications and helpful links

General Publications

• Wong QHY, Lui MW, Yung SSF, Ko JKY, Li RHW, Ng EHY. Randomized controlled trial of transcutaneous electrical nerve stimulation for pain relief during transvaginal oocyte retrieval using conscious sedation: study protocol for a randomized controlled trial. Trials. 2019 Apr 11;20(1):205. doi: 10.1186/s13063-019-3227-5.

Study record dates

Study Major Dates

• Study Start (Estimated): July 20, 2026
• Primary Completion (Estimated): February 20, 2027
• Study Completion (Estimated): March 10, 2027

Study Registration Dates

• First Submitted: July 13, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 16, 2026

Study Record Updates

• Last Update Posted (Actual): July 16, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Overactive Bladder; Transcutaneous Electrical Nerve Stimulation; Procedural Pain; Intravesical Injection
• Additional Relevant MeSH Terms: Urogenital Diseases; Pain; Neurologic Manifestations; Mental Disorders; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Lower Urinary Tract Symptoms; Urological Manifestations; Urinary Bladder Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Procedural; Anxiety Disorders; Urinary Bladder, Overactive
• Other Study ID Numbers: OAB-TENS-BTXA-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data will not be shared publicly. De-identified data may be made available upon reasonable request to the corresponding author, subject to institutional and ethics committee approval.
• IPD Sharing Time Frame: Data will be available beginning 6 months and ending 36 months after publication of the main results.
• IPD Sharing Access Criteria: De-identified data will be available to qualified researchers who provide a methodologically sound proposal, approved by the principal investigator and the local ethics committee. Requests should be directed to the corresponding author. A data use agreement may be required.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No