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.
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
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
Parallel
Active Transcutaneous Auricular Vagus Nerve Stimulation
DeviceActive 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.
Sham Transcutaneous Auricular Vagus Nerve Stimulation
DeviceSham 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 Program
Other interventionAll 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.
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.
Change in Complex Regional Pain Syndrome Severity Assessed With the CRPS Severity Score
Clinical severity of complex regional pain syndrome will be assessed using the CRPS Severity Score, which evaluates CRPS-related symptoms and clinical signs. The total score ranges from 0 to 16, with higher scores indicating greater disease severity. Change from baseline will be evaluated at weeks 4, 8, and 12.
Change in Hand Circumference
Hand circumference of the affected extremity will be measured in centimeters at a standardized anatomical reference point using a measuring tape. Three consecutive measurements will be obtained at each assessment, and the mean value will be recorded. Higher values indicate greater hand circumference. Change from baseline will be evaluated at weeks 4, 8, and 12.
Change in Wrist Circumference
Wrist circumference of the affected extremity will be measured in centimeters at a standardized anatomical reference point using a measuring tape. Three consecutive measurements will be obtained at each assessment, and the mean value will be recorded. Higher values indicate greater wrist circumference. Change from baseline will be evaluated at weeks 4, 8, and 12.
Change in Hand Function Assessed With the Duruöz Hand Index
Hand function and difficulty performing daily manual activities will be assessed using the 18-item Duruöz Hand Index. Each item is scored from 0 to 5, producing a total score ranging from 0 to 90. Higher scores indicate greater hand-related functional disability. Change from baseline will be evaluated at weeks 4, 8, and 12.
Click on the lead sponsor to view all of their trials.
This trial is not recruiting at the moment. You can still explore other options:
