NCT05230836

HFAC Stimulation (30-50 Kilohertz) in Healthy Volunteers (High Frequency Alternating Current Stimulation)

Effectiveness and Safety of Electrical Stimulation With Alternating High-frequency Currents (30-50 Kilohertz) on the Sensorimotor System in Healthy Volunteer Subjects

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 34 (estimated)
• Sponsor: University of Castilla-La Mancha · Academic / Other
• Sex: All
• Age: 18 Years – 40 Years
• Healthy volunteers: Accepted

Summary

High-frequency alternating current (HFAC) stimulation (between 1 kilohertz (kHz) and 100 kHz) on the peripheral nerve has been shown in basic animal research to produce a rapidly reversible nerve block without nerve damage. In human studies, frequencies between 1 kHz and 30 kHz had been applied (both transcutaneously and percutaneously), showing rapidly reversible sensorimotor changes after stimulation without adverse effects. However, the effect of currents with a frequency higher than 30 kHz, which has been shown to be more effective in eliciting nerve block in primates, has not been investigated in humans. The main objective of this study is to investigate the safety of the intervention and the effect in healthy volunteers of transcutaneous application of alternating currents with frequencies between 30 kHz and 50 kHz on neurophysiological changes in the nerve (nerve conduction velocity and antidromic sensory action potentials (SNAPs), sensory (pain to pressure, epicritic sensitivity and thermal pain to heat) and motor (maximal isometric force) components of the median nerve.

Detailed description

Electrical stimulation with high-frequency alternating currents (between 1 kHz and 100 kHz) on the peripheral nerve has shown, in basic research with animals, that it produces a rapidly reversible nerve block without causing damage to the nerve. In humans, studies have been carried out with frequencies between 1 kHz and 30 kHz applied both transcutaneously and percutaneously, showing rapidly reversible sensorimotor changes after stimulation and without causing adverse effects. However, the effect of currents with a frequency greater than 30 kHz has not been investigated in humans, which has been shown to be more effective in causing nerve block in primates. The main objective of this study is to investigate the safety of the intervention and the effect in healthy volunteers of the transcutaneous application of alternating currents with frequencies between 30 kHz and 50 kHz on neurophysiological changes in the nerve (nerve conduction velocity and antidromic sensory compound action potentials (PACSA), the sensitive component (pressure pain, epicritic sensitivity and thermal pain to heat) and motor (maximum force) of the median nerve. A randomized, double-blind, placebo-controlled crossover clinical trial has been designed. The participants will be healthy volunteers between 18 and 40 years old recruited from the students and staff of the Faculty of Physiotherapy and Nursing of the University of Castilla-La Mancha. Four interventions will be performed randomizing the order: Group A: 30 kHz, group B: 40 kHz, group C: 50 kHz and group D: sham electrical stimulation.

Conditions

• Healthy
• Nerve Block
• Pain

Interventions

Type	Name	Description
OTHER	High-frequency alternating current stimulation	For electrical stimulation in the active groups, unmodulated alternating currents with a symmetrical rectangular waveform of 30 kHz, 40 kHz and 50 kHz will be applied. The current intensity shall be adjusted individually for each participant by increasing the current intensity until the participant reports a "strong but comfortable tingling" sensation just below the excitomotor threshold on the palmar aspect of the hand in the dermatomes innervated by the median nerve. The intensity of the current shall be adjusted every two minutes if the tingling sensation decreases. This protocol has been used in previous studies conducted by our research group
OTHER	Sham current stimulation	Sham electrical stimulation will be performed with the same equipment and electrodes as in the active groups without the participants and the evaluator having a view of the device screen. The intensity of the current will be increased for 30 seconds until the sensory threshold ("strong but comfortable tingling sensation") is exceeded and once the threshold is reached, the intensity will be reduced to 0 mA with 30 seconds ramp down. Participants will not receive electrical current during the rest of the placebo intervention. This protocol was used in other studies with similar interventions to blind participants.

Timeline

• Start date: 2022-02-10
• Primary completion: 2022-09-20
• Completion: 2022-12-25
• First posted: 2022-02-09
• Last updated: 2022-05-16

Locations

1 site across 1 country: Spain