Effect of High Frequency Electrical Currents in Healthy Subjects.

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to determine whether the transcutaneous application of unmodulated high frequency alternating currents could produce a quickly conduction block of peripheral nerve.

Detailed Description
-----------------
In the last years several animal experimental studies have evidenced that high frequency unmodulated currents about 5 KHz can cause a peripheral nerve block. However electric currents with these high frequencies that are usually used for the treatment of pain in humans are interrupted or modulated (i.e. interferential currents). It has show that the diameter of the nerve it is related with the frequency to produce the conduction block. For this reason we decided to applied 30KHz to observe the effects on pain in patients with whiplash and to compare versus sham stimulation. Only one study has applied 5KHz on experimental pain and they have demonstrated changes in somatosensory thresholds.

Official Title
-----------------
Application of High Frequency Electrical Currents: Effects on Mechanical Threshold, Tactile Threshold and Evoked Potentials in Healthy Subjects.

Conditions
-----------------
High Frequency Current

Intervention / Treatment
-----------------
* Device: High-Frequency
* Device: Sham Stimulation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy volunteers Exclusion Criteria: Neuromuscular disease. Epilepsy. Trauma, surgery or pain affecting the upper limb, shoulder girdle or cervical area. Osteosynthesis material in the upper limb. Diabetes. Cancer. Cardiovascular disease. Pacemaker or other implanted electrical device. Take any drug (NSAIDs, corticosteroids, antidepressants, analgesics, antiepileptics, ...) during the study and in the previous 7 days. Presence of tattoos or other external agent introduced into the treatment or assessment area. Pregnancy.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-Frequency<br>Transcutaneous application of high frequency electrical current over the arm for a 30 minutes session. The intensity of the current will increase until participants report a strong but comfortable sensation, just below motor threshold. | Device: High-Frequency<br>* high-Frequency electrical stimulation over superficial radial nerve through the electrotherapy device Myomed 932. (Enraf-Nonius, Delft, Netherlands)<br>|
| Sham Comparator: Sham Stimulation<br>Electrodes are placed over the arm for a 30 minutes in the same manner as experimental group but will be applied a sham electrical stimulation increasing the current intensity of an unconnected channel. | Device: Sham Stimulation<br>* Sham transcutaneous electrical stimulation over superficial radial nerve through the electrotherapy device Myomed 932. (Enraf-Nonius, Delft, Netherlands)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Baseline Mechanical Pain Threshold | The pressure pain threshold will be measured by a pressure algometer and will be expressed in Newton | baseline at 0 min | 
| Baseline Tactile Threshold | The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton | baseline at 0 min | 
| Baseline Muscle Strength | The muscle strength will be measured with a dynamometer and will be expressed in Newton | Baseline at 0 min | 
| Mechanical Pain Threshold after treatment at 30 min | The pressure pain threshold will be measured by a pressure algometer and will be expressed in Newton | Immediately after treatment at 30 min | 
| Tactile Threshold after treatment at 30 min | The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton | Immediately after treatment at 30 min | 
| Muscle Strength after treatment at 30 min | The muscle strength will be measured with a dynamometer and will be expressed in Newton | Immediately after treatment at 30 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Mechanical Pain Threshold | The pressure pain threshold will be measured by a pressure algometer and will be expressed in Newton | baseline at 0 min, immediately after treatment at 30 min | 
| Change from baseline in TactileThreshold | The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton | baseline at 0 min, immediately after treatment at 30 min | 
| Change from baseline in Muscle strength | The muscle strength will be measured with a dynamometer and will be expressed in Newton | baseline at 0 min, immediately after treatment at 30 min | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Electric current, Nerve block, somatosensory evaluation