Percutaneous High Frequency Alternating Current Stimulation in Healthy Volunteers

Percutaneous High Frequency Alternating Current Stimulation: Effects on Somatosensory and Motor Threshold in Healthy Volunteers

High-frequency alternating currents of greater than 1 kHz applied on peripheral nerves has been used in animal studies to produce a motor nerve block. It has been evidenced that frequencies higher than 5 kHz are necessary to produce a complete peripheral nerve block in primates, whose nerve thickness is more similar to humans.

Study Overview

• Status: Completed
• Conditions: Electrical Stimulation; Neuromodulation
• Intervention / Treatment: Device: 10 kHz stimulation (Myomed 932, Enraf-Nonius); Device: 20 kHz stimulation (Myomed 932, Enraf-Nonius); Device: Sham stimulation (Myomed 932, Enraf-Nonius)

Detailed Description

Our previous studies with transcutaneous HFAC, suggest high-frequency stimulation (10 and 20 kHz) have an inhibitory effect over muscle strength and somatosensory threshold.

However, in these studies the intensity needed to reach block threshold is very high. The purpose of the present work is to reduce the amount of current intensity needed using a percutaneous approach by apply two acupuncture needles near the nerve as electrodes.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Toledo, Spain, 45071
    • Castilla-La Mancha University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 56 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy volunteers
• Ability to perform all clinical tests and understand the study process, as well as obtaining informed consent.
• Tolerance to the application of electrotherapy.
• That they have not diagnosed any pathology.
• They do not present a contraindication to puncture and / or the application of electric currents.

Exclusion Criteria:

• Neuromuscular disease.
• Epilepsy.
• Trauma, surgery or pain affecting the upper limb
• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 10 kHz stimulation; Transcutaneous application of high frequency electrical current at 10 kHz over the median nerve for a 20 minutes session. The intensity of the current will increase until participants report a "strong but comfortable" sensation, just below motor threshold.	Device: 10 kHz stimulation (Myomed 932, Enraf-Nonius); A charge-balanced, symmetric, biphasic sinusoidal current without modulation will be delivered at a frequency of 10 kHz. The stimulation intensity will be defined as that sufficient to produce a "strong but comfortable" sensation, just below motor threshold, over the median nerve through the electrotherapy device Myomed 932. (Enraf-Nonius, Delft,Netherlands)
Experimental: 20 kHz stimulation; Transcutaneous application of high frequency electrical current at 20 kHz over the median nerve for a 20 minutes session. The intensity of the current will increase until participants report a "strong but comfortable" sensation, just below motor threshold.	Device: 20 kHz stimulation (Myomed 932, Enraf-Nonius); A charge-balanced, symmetric, biphasic sinusoidal current without modulation will be delivered at a frequency of 20 kHz. The stimulation intensity will be defined as that sufficient to produce a "strong but comfortable" sensation, just below motor threshold, over the median nerve through the electrotherapy device Myomed 932. (Enraf-Nonius, Delft,Netherlands)
Sham Comparator: Sham stimulation; Electrodes are placed over the median nerve for 20 minutes in the same manner as experimental group but will be applied a sham electrical stimulation increasing the current intensity during the first 30 seconds.	Device: Sham stimulation (Myomed 932, Enraf-Nonius); Sham stimulation will be delivered at a frequency of 10 kHz only during the first 30 seconds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Antidromic median sensory nerve action potential	The recording electrodes were placed on the second finger and the stimulus will be applied on the median nerve (above the elbow joint). The stimulus will consist of a train of 10 pulses (100 μs width), applied at supramaximal stimulation, presented at 1 Hz (DS7A, Digitimer Ltd). Negative peak latency (NPL), positive peak latency (PPL), and peak-to-peak amplitude (PPA) will be registered with a specific software (Signal software, CED).	Baseline at 0 minutes
Tactile Threshold	The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton	Baseline at 0 minutes
Oscillation Frequency of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The frequency of the damped oscillations characterizes the muscle tone. The muscle will be assessed is opponens pollicis muscle	Baseline at 0 minutes
Stiffness of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. Stiffness reflects the resistance of the muscle to the force deforming the muscle. The muscle will be assessed is opponens pollicis muscle	Baseline at 0 minutes
Decrement (elasticity) of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The logarithmic decrement of the damping oscillations characterizes muscle elasticity which is the ability of the muscle to restore its initial shape after contraction. The muscle will be assessed is opponens pollicis muscle	Baseline at 0 minutes
Pressure Pain Threshold	The PPT will be measured with an algometer and will be expressed in Newtons	Baseline at 0 minutes
Muscle strength	Muscle strength will be measured with a dynamometer and will be expressed in Kgs.	Baseline at 0 minutes
Tactile Threshold	The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton	During treatment at 15 minutes
Oscillation Frequency of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The frequency of the damped oscillations characterizes the muscle tone. The muscle will be assessed is opponens pollicis muscle	During treatment at 15 minutes
Stiffness of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. Stiffness reflects the resistance of the muscle to the force deforming the muscle. The muscle will be assessed is opponens pollicis muscle	During treatment at 15 minutes
Decrement (elasticity) of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The logarithmic decrement of the damping oscillations characterizes muscle elasticity which is the ability of the muscle to restore its initial shape after contraction. The muscle will be assessed is opponens pollicis muscle	During treatment at 15 minutes
Pressure Pain Threshold	The PPT will be measured with an algometer and will be expressed in Newtons	During treatment at 15 minutes
Antidromic median sensory nerve action potential	The recording electrodes were placed on the second finger and the stimulus will be applied on the median nerve (above the elbow joint). The stimulus will consist of a train of 10 pulses (100 μs width), applied at supramaximal stimulation, presented at 1 Hz (DS7A, Digitimer Ltd). Negative peak latency (NPL), positive peak latency (PPL), and peak-to-peak amplitude (PPA) will be registered with a specific software (Signal software, CED).	Immediately after treatment at 20 minutes
Tactile Threshold	The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton	Immediately after treatment at 20 minutes
Oscillation Frequency of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The frequency of the damped oscillations characterizes the muscle tone. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 20 minutes
Stiffness of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. Stiffness reflects the resistance of the muscle to the force deforming the muscle. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 20 minutes
Decrement (elasticity) of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The logarithmic decrement of the damping oscillations characterizes muscle elasticity which is the ability of the muscle to restore its initial shape after contraction. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 20 minutes
Pressure Pain Threshold	The PPT will be measured with an algometer and will be expressed in Newtons	Immediately after treatment at 20 minutes
Muscle strength	Muscle strength will be measured with a dynamometer and will be expressed in Kgs.	Immediately after treatment at 20 minutes
Antidromic median sensory nerve action potential	The recording electrodes were placed on the second finger and the stimulus will be applied on the median nerve (above the elbow joint). The stimulus will consist of a train of 10 pulses (100 μs width), applied at supramaximal stimulation, presented at 1 Hz (DS7A, Digitimer Ltd). Negative peak latency (NPL), positive peak latency (PPL), and peak-to-peak amplitude (PPA) will be registered with a specific software (Signal software, CED).	Immediately after treatment at 30 minutes
Tactile Threshold	The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton	Immediately after treatment at 30 minutes
Oscillation Frequency of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The frequency of the damped oscillations characterizes the muscle tone. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 30 minutes
Stiffness of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. Stiffness reflects the resistance of the muscle to the force deforming the muscle. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 30 minutes
Decrement (elasticity) of tissue assessed by MyotonPro	This outcome measure is obtained by a device named MyotonPro. The logarithmic decrement of the damping oscillations characterizes muscle elasticity which is the ability of the muscle to restore its initial shape after contraction. The muscle will be assessed is opponens pollicis muscle	Immediately after treatment at 30 minutes
Pressure Pain Threshold	The PPT will be measured with an algometer and will be expressed in Newtons	Immediately after treatment at 30 minutes
Muscle strength	Muscle strength will be measured with a dynamometer and will be expressed in Kgs.	Immediately after treatment at 30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Baseline nerve temperature	Nerve temperature will be measured using a termodoppler (Celsius degrees)	Baseline at 0 minutes, at 15 minutes, immediately after treatment at 20 minutes, and immediately after treatment at 30 minutes
Baseline flux temperature	Flux will be measured using a termodoppler	Baseline at 0 minutes, at 15 minutes, immediately after treatment at 20 minutes, and immediately after treatment at 30 minutes
Numerical Discomfort Rate Score	the possible discomfort caused by the interventions will be assess by a numerical rate score. The NRS consists of a scale from 0 (no discomfort) to 10 (worst possible discomfort)	After the intervention at 35 minutes
Numerical Pain Rate Score	The NRS consists of a scale from 0 (no pain) to 10 (worst possible pain)	After the intervention at 35 minutes
Number of participants with intervention-related adverse effects	the possible adverse effects caused by the interventions will be assess by a questionnaire	After the intervention at 35 minutes
Blinding success	Blinding of subjects and researchers will be assessed using the James Index	After the intervention at 35 minutes

Collaborators and Investigators

• Sponsor: University of Castilla-La Mancha
• Investigators: Study Director: Juan Avendaño-Coy, PhD, Castilla-La Mancha University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2020
• Primary Completion (Actual): November 17, 2020
• Study Completion (Actual): November 17, 2020

Study Registration Dates

• First Submitted: April 2, 2020
• First Submitted That Met QC Criteria: April 10, 2020
• First Posted (Actual): April 15, 2020

Study Record Updates

• Last Update Posted (Actual): November 18, 2020
• Last Update Submitted That Met QC Criteria: November 17, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Keywords: nerve block; motor threshold; high-frequency alternating current; somatosensory threshold; percutaneous electrical stimulation
• Other Study ID Numbers: Neuromodest-pHFAC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No