Transcutaneous Auricular Vagus Nerve Stimulation Added to Rehabilitation for Complex Regional Pain Syndrome Type I

Summary

This randomized, participant- and assessor-blinded, sham-controlled study will evaluate the effectiveness of transcutaneous auricular vagus nerve stimulation (taVNS) added to standard rehabilitation in adults with complex regional pain syndrome type I (CRPS-I) affecting the hand or upper extremity.

A total of 20 participants will be randomly assigned to two parallel groups. Both groups will receive the same standard rehabilitation program 5 days per week for 4 weeks. In addition, the experimental group will receive active taVNS, while the control group will receive sham taVNS for 30 minutes per session over the same 4-week period.

The primary outcome is change in pain intensity measured using the Numerical Rating Scale. Secondary outcomes include CRPS clinical severity, hand and wrist circumference, hand function and activities of daily living, health-related quality of life, anxiety and depression symptoms, and perceived stress. Assessments will be performed at baseline, at the end of treatment at week 4, and during follow-up at weeks 8 and 12.

Conditions

• Complex Regional Pain Syndrome Type I

Interventions

DEVICE

Active Transcutaneous Auricular Vagus Nerve Stimulation

Active transcutaneous auricular vagus nerve stimulation will be applied to the auricular concha region for 30 minutes per session, 5 days per week for 4 weeks, for a total of 20 sessions. Stimulation intensity will be individually adjusted to produce a tolerable paresthesia without pain. The intervention will be administered by a trained physiotherapist in addition to the standard rehabilitation program.

DEVICE

Sham Transcutaneous Auricular Vagus Nerve Stimulation

Sham transcutaneous auricular vagus nerve stimulation will be administered using the same device, session duration, and treatment schedule as active taVNS: 30 minutes per session, 5 days per week for 4 weeks, for a total of 20 sessions. The electrode placement and/or stimulation parameters will be configured according to a prespecified sham protocol intended not to produce therapeutic vagal stimulation. The sham intervention will be administered by a trained physiotherapist in addition to the standard rehabilitation program.

OTHER

Standard Rehabilitation Program

All participants will receive the standard physical therapy and rehabilitation program routinely used in our clinic for patients with CRPS-I and based on current literature. The program will include contrast baths, transcutaneous electrical nerve stimulation, desensitization techniques, passive and active range-of-motion exercises, isometric and isotonic strengthening exercises, progressive loading exercises, hand dexterity and coordination activities, and functional training focused on activities of daily living. The rehabilitation program will be administered 5 days per week for 4 weeks.

Sponsors & Collaborators

• Liv Hospital Vadistanbul

  lead OTHER

Principal Investigators

• Muhsin Doran · Liv Hospital Vadistanbul

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-07-15

Primary Completion

2027-02-15

Completion

2027-02-15