Effect of taVNS on Abdominal Pain and Other Symptoms in Constipation-predominant Irritable Bowel Syndrome

Tongji University42 enrolled

Overview

This study aims to investigate the effects and possible mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) on abdominal pain and other symptoms in patients with IBS-C.

This study is designed as an early-feasibility, single-center, single-blinded, randomized controlled trial (RCT), in which subjects are consented, undergo a baseline assessment, and receive taVNS or sham-taVNS treatment twice a day (8 a.m. and 8 p.m.) for 30 minutes each time for a period of 4 weeks. The taVNS and sham-taVNS treatment was applied using the commercially-available Transcutaneous Electrical Applicator device (Model SNM-FDC01, Ningbo MedKinetic Medical Device Co., Ltd.) with the skin electrodes placed bilaterally on auricular concha. The patients are requested to score the abdominal pain (using VAS) and complete BSFS, IBS-SSS, IBS-QOL, SAS, and SDS forms every week and fill out the bowel diary during taVNS or sham-taVNS. Emergency medications (Macrogol 4000 and pinaverium) are permitted for use when the patient cannot tolerate symptoms of constipation and abdominal pain.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Constipation-predominant Irritable Bowel Syndrome Abdominal Pain

Interventions

taVNSDEVICE

transcutaneous auricular vagal nerve stimulation

sham-taVNSDEVICE

transcutaneous stimulation at the elbow area

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: 1. willing to sign a written informed consent form 2. met the Rome IV diagnostic criteria for IBS-C Exclusion Criteria: 1. history of previous abdominal surgery (other than appendectomy) 2. presence of carcinoma 3. any organic diseases causing constipation or neurologic diseases such as multiple sclerosis, rachischisis, Parkinson's disease, or spinal cord injury 4. taking antidepressant agents including tricyclic antidepressants and selective serotonin reuptake inhibitors 5. serious concomitant disease of the heart, liver, kidney, or diabetes 6. pregnancy or lactation 7. participating in another trial or enrolled in a trial during the past month 8. allergic reaction to surface electrodes

Locations (1)

Shanghai East Hospital, Tongji University School of Medicine

Shanghai, China

Outcomes

Primary Outcomes

Change in аbdominal pain between sham and active taVNS

Weekly average of daily patient-assessed abdominal pain using the visual analog scale (VAS). VAS ranges from 0 to 10, with 0 indicating no abdominal pain and 10 indicating the maximal pain. Efficacy is evaluated as an improvement of ≥ 30%.

Time frame: 4 weeks

Secondary Outcomes

Change in IBS symptom severity scale (IBS-SSS) between sham and active taVNS

Questionnaire consists of 5 questions (abdominal pain intensity, abdominal pain frequency, abdominal distension degree, defecation satisfaction, and interference with quality of life), with a total score of 500 points and a higher score indicating a worse condition. Scores \< 175 represent mild IBS symptoms, scores 175-300 represent moderate severity, and scores \> 300 represent severe IBS.

Time frame: 4 weeks

Change in IBS quality of life (IBS-QOL) between sham and active taVNS

Questionnaire is composed of 8 dimensions (dysphoria, interference with activity, body image, health concerns, food avoidance, social reaction, sex, and relationships), with 34 items assessing the degree to which IBS interferes with the patient's quality of life. Each item is evaluated on a 5-point Likert scale. The total score ranges from 34 to 170 and higher scores indicate better quality of life.

Time frame: 4 weeks

Change in Bristol stool form scale (BSFS) between sham and active taVNS

The scale has 7 points according to stool type, from the hardest (1) to the softest (7). The lower the score, the more severe is constipation.

Time frame: 4 weeks

Change in Self-Rating Anxiety Scale (SAS) score between sham and active taVNS

SAS questionnaire has 20 items to assess physical and psychological symptoms, using a 4-point Likert scale ranging from 1 (none, or a little of the time) to 4 (most, or all of the time), with a total score ranging from 20 to 80. SAS scores below 50 indicate no anxiety, from 50 to 59 - mild anxiety, from 60 to 69 - moderate anxiety, 70 and above - severe anxiety.

Data from ClinicalTrials.gov

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