Noninvasive Brain Stimulation for Treating Carpal Tunnel Syndrome

Study Overview
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Brief Summary
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The purpose of this study is to assess the effects of tDCS in combination with TUS for the treatment of pain in subjects with Carpal Tunnel Syndrome. The investigators hypothesize that there will be a decrease in pain levels with active stimulation, when compared to sham stimulation.

Official Title
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Noninvasive Brain Stimulation for Treating Carpal Tunnel Syndrome

Conditions
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Chronic Pain, Carpal Tunnel Syndrome

Intervention / Treatment
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* Device: transcranial Direct Current Stimulation (tDCS)
* Device: Transcranial Ultrasound (TUS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Able to provide informed consent to participate in the study Subjects between 18 to 80 years old Having symptomatic CTS spreading within or beyond the median nerve distribution (demonstrating 'extra-median spread'), involving at least 1 wrist, with chronic pain as defined by International Association for the Study of Pain (existing pain for at least 6 months and having pain on at least half the days in the past 6 months with an average of at least a 3 on a 0-10 VAS scale). Pain resistant to first line therapies of chronic pain (pain still present at lower levels most of the time following therapy) Must have the ability to feel pain as self-reported. Exclusion Criteria: Subject is pregnant Contraindications to tDCS+TUS: intracranial metal implant implanted brain medical devices History of alcohol or drug abuse within the past 6 months as self-reported Use of carbamazepine within the past 6 months as self-reported Suffering from major depression (with a PHQ-9 score of ≥20) History of neurological disorders involving stroke, brain tumors, or epilepsy with residual neurological symptoms as self-reported (note patients will also be evaluated via EEG at baseline about 1 week prior to stimulation and any patient showing abnormal EEG activity will be removed)) History of unexplained fainting spells as self-reported History of head injury resulting in more than a momentary loss of consciousness as self-reported and with current neurological deficits History of intracranial neurosurgery as self-reported

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active tDCS + Active TUS<br>Subjects in the experimental group will undergo 20 minutes of active transcranial direct current stimulation (tDCS) and active transcranial ultrasound (TUS). | Device: transcranial Direct Current Stimulation (tDCS)<br>* Subjects will receive 20 minutes of either active or sham tDCS at intensity of 2mA. In the sham group, the tDCS device will not be active for the full 20 minutes.<br>Device: Transcranial Ultrasound (TUS)<br>* Subjects will receive 20 minutes of either active or sham TUS. During active stimulation the ultrasound will be active for the full 20 minutes- however, during sham stimulation the ultrasound will not be active for the full 20 minutes.<br>|
| Sham Comparator: Sham tDCS + Sham TUS<br>Subjects in the sham group will undergo 20 minutes of sham transcranial direct current stimulation (tDCS) and sham transcranial ultrasound (TUS). | Device: transcranial Direct Current Stimulation (tDCS)<br>* Subjects will receive 20 minutes of either active or sham tDCS at intensity of 2mA. In the sham group, the tDCS device will not be active for the full 20 minutes.<br>Device: Transcranial Ultrasound (TUS)<br>* Subjects will receive 20 minutes of either active or sham TUS. During active stimulation the ultrasound will be active for the full 20 minutes- however, during sham stimulation the ultrasound will not be active for the full 20 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analogue Score (VAS) | Changes in the Visual Analogue Scale (VAS) for pain will be measured in order to determine whether anodal transcranial direct current stimulation in conjunction with transcranial ultrasound is effective in reducing pain in subjects with Carpal Tunnel Syndrome. The VAS scale goes from 0 up to 10, where 0 means no pain at all and 10 means the worst imaginable pain. | 9 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Verbal Rating Scale (VRS) | Changes in the Verbal Rating Scale (VRS) for pain will be measured in order to determine whether anodal transcranial direct current stimulation in conjunction with transcranial ultrasound is effective in reducing pain in subjects with Carpal Tunnel Syndrome. The VRS minimum value is no pain and the maximum value is severe pain. Being severe pain the worst outcome. | Measured for approximately for a total 9 weeks | 
| Visual Analog Mood Scale (VAMS) | The investigators will measure safety of tDCS and TUS by measuring changes in the Visual Analog Mood Scale. This scale will range from zero (low or worst mood) to 10 on anxiety, depression, sleepiness and stress. | Measured for approximately for a total 9 weeks | 
| Montreal Cognitive Assessment (MOCA) | The investigators will monitor the safety of tDCS and TUS in subjects by measuring any changes in cognition, attention, and focus with the MOCA. MOCA scores range between 0 and 30, a score of 26 and higher generally considered normal. | Measured for approximately for a total 9 weeks | 
| tDCS Side Effects Questionnaire | At each session, subjects will complete a questionnaire to evaluate potential adverse effects of stimulation (headache, neck pain, mood alterations, and seizures) on a 4-point scale, where 1 is absent and 4 is severe. The scale will also be administered at the follow-ups. | Measured for approximately for a total 9 weeks | 
| Patient Health Questionnaire (PHQ-9) | The investigators will measure safety of tDCS and TUS by measuring changes of mood through the PHQ-9. The scoring goes from 0 to 27, where 0 is no depression and 27 is severe depression. | Measured for approximately for a total 9 weeks | 
| Multidimensional Pain Inventory (MPI) | The investigators will monitor the impact of pain with the MPI of tDCS and TUS. It consist in 3 sections (Pain Impact , responses by significant others, activities and each item is rated on a 7-point scale (0-6), where higher scores represent severe symptoms . | Measured for approximately for a total 9 weeks | 
| Neuropathic Pain Symptom Inventory (NPSI) | The investigators will monitor the changes of neuropathic pain in subjects going through the study before and after tDCS and TUS. It include 12 items in total, this tool evaluates mean pain intensity in the last 24 hours in a numeric scale from zero (no pain) to 10 (worst imaginable pain). Total pain intensity score may be calculated by the sum of 10 descriptors | Measured for approximately for a total 9 weeks | 
| Temporal Summation (TS) | The investigators will monitor the changes of temporal summation in the study before and after tDCS and TUS. This will be assessed by Von Frey filaments. This is assessed by having the participant rate their pain after a single stimulus (6.65, 300 g) applied for 0.5 s and then again after a series of 10 (6.65, 300 g) stimuli are applied at 1-s intervals. | Measured for approximately for a total 9 weeks | 
| Conditioned pain modulation (CPM) | Changes in the conditioned pain modulation will be measured in order to determine whether anodal transcranial direct current stimulation in conjunction with transcranial ultrasound is effective in changing the conditioned pain modulation system in subjects with Carpal Tunnel Syndrome. This will be assessed by applying pressure with an algometer. | Measured for approximately for a total 9 weeks | 
| Vibration Detection Threshold (VDT) | Changes in the vibration detection threshold will be measured , this is performed with a Rydel-Seiffer tuning fork (64 Hz, 8/8 scale) placed on the skin surface and is determined by asking the participant to tell the examiner when the vibration is no longer felt. | Measured for approximately for a total 9 weeks | 
| Michigan Hand Outcomes Questionnaire (MHQ) | This a hand-specific outcomes instrument that measures outcomes of patients with conditions of, or injury to, the hand or wrist. The MHQ contains six distinct scales: overall hand function, activities of daily living , pain, work performance, aesthetics, and patient satisfaction with hand function. They are scored from 0 - 100 in which 100 is the best possible ability | Measured for approximately for a total 9 weeks | 
| Boston Carpal Tunnel Questionnaire | This is an instrument specifically designed for Carpal Tunnel Syndrome (CTS) and validated for CTS therapy assessments (consisting of the Functional Status Scale and Symptom Severity Scale scores. The symptom severity scale has 11 questions scored from 1 point (mildest) to 5 points (most severe). | Measured for approximately for a total 9 weeks | 
| The Medical Outcomes Study 36-Item Short Form (SF-36) | This a generic health status instrument that measures 8-health related concepts using 36 questions and provides a profile of functional health and well-being scores. It also provides a psychometrical index of physical and mental health. Each scale is transformed into a 0-100 scale. The lower the score the more disability. The higher the score the less disability | Measured for approximately for a total 9 weeks | 
| Electroencephalography (EEG) | Investigators will measure electroencephalogram activity to monitor safety. Baseline recordings will be reviewed to ensure that there are no potential electroencephalographic safety criteria prior to stimulation. This qualitative analysis will focus on pathological EEG activity such as epileptiform discharges or persistent focal slowing. | Measured for approximately for a total 3 weeks | 
| Strength (grip and pinch) | Strength will be assessed using a grip dynamometer and a pinch dynamometer | Measured for approximately for a total 9 weeks | 
| Range of Motion (ROM) | The investigators will assess active and passive ROM in the elbow, forearm, wrist, thumb, digits | Measured for approximately for a total 9 weeks | 
| Thumb Reaching Test | Subject will be asked to reach the base of the little finger with their thumb. The task will be repeated up to 10 times. Primary data will be taken from inertial sensors placed on the thumb and little finger. | Measured for approximately for a total 9 weeks | 
| Reach to Pinch | Subject will be asked to perform a reach to pinch task . The task will be repeated up to 10 times. Primary data will be taken from camera and accelerometers/gyroscopes placed on the thumb and index finger. | Measured for approximately for a total 9 weeks | 
| Wrist Flexion-Extension: | Subject will be asked to flex-extend their wrist up to 10 times. Primary data will be taken from an accelerometer/gyroscope placed on the wrist and the camera. | Measured for approximately for a total 9 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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transcranial Direct Current Stimulation, Transcranial Ultrasound, Noninvasive brain stimulation