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Percutaneous High Frequency Alternating Current Stimulation in Healthy Volunteers

Not Applicable
Completed
Conditions
Electrical Stimulation
Neuromodulation
Interventions
Device: Sham stimulation (Myomed 932, Enraf-Nonius)
Device: 20 kHz stimulation (Myomed 932, Enraf-Nonius)
Device: 10 kHz stimulation (Myomed 932, Enraf-Nonius)
Registration Number
NCT04346719
Lead Sponsor
University of Castilla-La Mancha
Brief Summary

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.

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
60
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 & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Sham stimulationSham stimulation (Myomed 932, Enraf-Nonius)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.
20 kHz stimulation20 kHz stimulation (Myomed 932, Enraf-Nonius)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.
10 kHz stimulation10 kHz stimulation (Myomed 932, Enraf-Nonius)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.
Primary Outcome Measures
NameTimeMethod
Muscle strengthImmediately after treatment at 30 minutes

Muscle strength will be measured with a dynamometer and will be expressed in Kgs.

Antidromic median sensory nerve action potentialImmediately after treatment at 30 minutes

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).

Decrement (elasticity) of tissue assessed by MyotonProImmediately after treatment at 30 minutes

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

Tactile ThresholdImmediately after treatment at 30 minutes

The tactile threshold will be measured with Von Frey filaments and will be expressed in millinewton

Stiffness of tissue assessed by MyotonProImmediately after treatment at 30 minutes

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

Oscillation Frequency of tissue assessed by MyotonProImmediately after treatment at 30 minutes

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

Pressure Pain ThresholdImmediately after treatment at 30 minutes

The PPT will be measured with an algometer and will be expressed in Newtons

Secondary Outcome Measures
NameTimeMethod
Number of participants with intervention-related adverse effectsAfter the intervention at 35 minutes

the possible adverse effects caused by the interventions will be assess by a questionnaire

Blinding successAfter the intervention at 35 minutes

Blinding of subjects and researchers will be assessed using the James Index

Baseline flux temperatureBaseline at 0 minutes, at 15 minutes, immediately after treatment at 20 minutes, and immediately after treatment at 30 minutes

Flux will be measured using a termodoppler

Numerical Pain Rate ScoreAfter the intervention at 35 minutes

The NRS consists of a scale from 0 (no pain) to 10 (worst possible pain)

Baseline nerve temperatureBaseline at 0 minutes, at 15 minutes, immediately after treatment at 20 minutes, and immediately after treatment at 30 minutes

Nerve temperature will be measured using a termodoppler (Celsius degrees)

Numerical Discomfort Rate ScoreAfter the intervention at 35 minutes

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)

Trial Locations

Locations (1)

Castilla-La Mancha University

🇪🇸

Toledo, Spain

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