Noninvasive Brain Stimulation for Treating Carpal Tunnel Syndrome

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.

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.

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.

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.

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.

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.

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 .

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

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.

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.

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.

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

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).

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

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.

Strength will be assessed using a grip dynamometer and a pinch dynamometer

The investigators will assess active and passive ROM in the elbow, forearm, wrist, thumb, digits

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.

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.

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.