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

NCT07711392 | Not Yet Recruiting

• 1 other identifier: LIV-FTR-taVNS-CRPS1-2026-01
• Study Type: interventional
• Target: 20
• Locations: 0 countries
• Sites: N/A

Brief 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

Outcome Measures

Primary Outcomes (1)

• Change in Pain Intensity Assessed With the Numerical Rating Scale

  Pain intensity will be assessed using an 11-point Numerical Rating Scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate greater pain intensity. Change from baseline will be evaluated at weeks 4, 8, and 12.

  Baseline and weeks 4, 8, and 12

Secondary Outcomes (4)

• Change in Complex Regional Pain Syndrome Severity Assessed With the CRPS Severity Score

  Baseline and weeks 4, 8, and 12

• Change in Hand Circumference

  Baseline and weeks 4, 8, and 12

• Change in Wrist Circumference

  Baseline and weeks 4, 8, and 12

• Change in Hand Function Assessed With the Duruöz Hand Index

  Baseline and weeks 4, 8, and 12

Study Arms (2)

Standard Rehabilitation Plus Active taVNS

EXPERIMENTAL

Participants will receive a standard rehabilitation program 5 days per week for 4 weeks. The program will include contrast baths, transcutaneous electrical nerve stimulation, heat therapy, desensitization techniques, passive and active range-of-motion exercises, strengthening, progressive loading, hand dexterity and coordination activities, and functional training. In addition, active transcutaneous auricular vagus nerve stimulation will be administered for 30 minutes per session, 5 days per week for 4 weeks, for a total of 20 sessions.

Device: Active Transcutaneous Auricular Vagus Nerve Stimulation; Other: Standard Rehabilitation Program

Standard Rehabilitation Plus Sham taVNS

SHAM COMPARATOR

Participants will receive the same standard rehabilitation program 5 days per week for 4 weeks, including contrast baths, transcutaneous electrical nerve stimulation, heat therapy, desensitization techniques, passive and active range-of-motion exercises, strengthening, progressive loading, hand dexterity and coordination activities, and functional training. In addition, sham transcutaneous auricular vagus nerve stimulation will be administered for 30 minutes per session, 5 days per week for 4 weeks, for a total of 20 sessions, using a prespecified sham protocol not expected to produce therapeutic vagal stimulation.

Device: Sham Transcutaneous Auricular Vagus Nerve Stimulation; Other: Standard Rehabilitation Program

Interventions

Standard Rehabilitation Program OTHER

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.

Standard Rehabilitation Plus Active taVNS; Standard Rehabilitation Plus Sham taVNS

Active Transcutaneous Auricular Vagus Nerve Stimulation DEVICE

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.

Standard Rehabilitation Plus Active taVNS

Sham Transcutaneous Auricular Vagus Nerve Stimulation DEVICE

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.

Standard Rehabilitation Plus Sham taVNS

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnosis of complex regional pain syndrome type I according to the Budapest diagnostic criteria
• Age 18 to 65 years
• CRPS type I affecting the hand following a traumatic cause, including surgery, fracture, and/or immobilization of the hand or upper extremity
• Willingness to participate in the study and provision of written informed consent

You may not qualify if:

• Diagnosis of complex regional pain syndrome type II
• CRPS type I developing after stroke
• Acute or post-acute rehabilitation following hand tendon repair
• Presence of a comorbid condition that may substantially affect functional status or health-related quality of life, including decompensated heart failure, chronic kidney failure, or malignancy
• Arthritis affecting the hand
• Acute arterial or venous thrombosis of the upper extremity
• History of arterial or venous injury of the upper extremity

Sponsors & Collaborators

• Liv Hospital Vadistanbul: lead

MeSH Terms

Conditions

Complex Regional Pain Syndromes

Condition Hierarchy (Ancestors)

Autonomic Nervous System Diseases; Nervous System Diseases; Peripheral Nervous System Diseases; Neuromuscular Diseases

Study Officials

• Muhsin Doran

  Liv Hospital Vadistanbul

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Muhsin Doran, MD

CONTACT

00905340807940; muhsin-doran@hotmail.com

muhsin doran, MD

CONTACT

00904444548; muhsin-doran@hotmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Participants and the outcomes assessor will be blinded to group allocation. The physiotherapist administering active or sham transcutaneous auricular vagus nerve stimulation will be aware of the assigned intervention and will not participate in outcome assessments. Participants in both groups will receive stimulation with the same session duration and frequency
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Physical Medicine and Rehabilitation Specialist

Model Details: Participants will be randomly assigned in a 1:1 ratio to two parallel groups: standard rehabilitation plus active transcutaneous auricular vagus nerve stimulation or standard rehabilitation plus sham transcutaneous auricular vagus nerve stimulation. Participants will remain in their assigned groups throughout the study, with no crossover between groups.

Study Record Dates

• First Submitted: July 14, 2026
• First Posted: July 17, 2026
• Study Start: July 15, 2026
• Primary Completion (Estimated): February 15, 2027
• Study Completion (Estimated): February 15, 2027
• Last Updated: July 17, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share