An interventional study of stimulation of G13 then G15 and stimulation of G15 then G13 in Vasoconstriction Disorder of Extremities, sponsored by Hôpital Européen Marseille. Terminated at 1 site in France. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-09-25.
Sponsored by Hôpital Européen Marseille · Not applicable, Interventional, and Other
While invasive vagal stimulation has proven its therapeutic effectiveness over the past 20 years, particularly in the treatment of epilepsy or depression, its implementation is hampered by the high cost, high technicality and sometimes significant side effects. Non-invasive vagal stimulation, most often electric, is a less expensive therapeutic alternative and easier to implement, although the level of evidence is lower than that of invasive stimulation.
Some so-called traditional therapies, such as acupuncture, also stimulate certain parts of the ear by mechanical means, most often by puncturing the ear or the concha. In these traditional therapies, more than one hundred stimulation points have been described, each precisely positioned according to an empirical topography.
However, electrical non-invasive stimulation recognizes only three areas of interest on the ear, which are the areas of sensitive innervation, namely the afferences of the vagus nerve in the concha, which is the only one used in practice, the large occipital nerve on the lobe and part of the helix, and the auriculotemporal nerve on the rest of the auricular flag.
In this study, we would like to explore the justification for the topographic precision, adopted by traditional therapies, for non-invasive vagal stimulation on the concha.
Main objective: to measure the physiological impact of two auricular stimuli on the same innervation territory but with opposite actions according to traditional therapies.
An identical physiological response on both stimulation points would be an argument against the topographical precision adopted by traditional therapies; conversely, a different physiological response would suggest the existence of a somatotopy nestled in the same innervation territory.
Secondary objectives:
To explore the justification for the topographical precision adopted by traditional therapies, we designed an experiment that consists of studying the autonomous, sympathetic and parasympathetic response to two stimuli performed over two different times.
The sympathetic stimulation will be done by immersing the right hand up to the wrist in a tub of cold water maintained at 5°C Mechanical parasympathetic stimulation will be performed on the ear in two different locations, by placing an adapted needle through an introducer to respect a standardized insertion depth.
The autonomous response will be measured by sinus variability, which responds to a double innervation, sympathetic and parasympathetic, and by the capillary skin response, which responds only to a sympathetic innervation.
The capillary skin response is measured by the amplitude and latency of the paradoxical vasodilation reflex following thermal stimulation, in this case the immersion of a limb's tip in cold water.
The study will consist of 3 sessions, as shown in the figure below. This is a prospective crossover study.
During the first session, the inclusion and non-inclusion criteria will be checked, then a water immersion test will be carried out to ensure the good tolerance of this test and then determine the basic values.
In the absence of acclimatization, the paradoxical vasodilation reflex is highly reproducible. During the second and third sessions, a mechanical stimulation will be done to the ear during the skin immersion test.
Hôpital Européen Marseille is the lead sponsor of 30 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
The first session is similar between the two arms: Cold water hand immersion only At the Second session: Cold water hand immersion + G13 auricular stimulation At the Third session: Cold water hand immersion + G15 auricular stimulation
Behavioral: stimulation of G13 then G15
The first session is similar between the two arms: Cold water hand immersion only At the Second session: Cold water hand immersion + G15 auricular stimulation At the Third session: Cold water hand immersion + G13 auricular stimulation
Behavioral: stimulation of G15 then G13
Study participant randomized into arm A will undergo a stimulation of point G13 at session N°2, then stimulation of point G15 at session N°3.
Study participant randomized into arm B will undergo a stimulation of point G15 at session N°2, then stimulation of point G13 at session N°3.
Skin temperature changes
measured by thermocouples placed on the following fingers: thumb, middle finger and ear of the right hand. The values and times of the minimum and maximum temperatures (latency and amplitude of (CIVD) Cold-Induced VasoDilatation waves) are measured
Time frame: 20 minutes
Pain reported by the participant
Measured by visual analogue scale; this scale ranges from 0 to 10; 0 being no pain, 10 being excruciating pain.
Time frame: 20 minutes
Sinus variability
measured by cardiofrequency meter(ACTIWAVE ®)
Time frame: 20 minutes
This study is terminated, as verified in Jan 2022. You cannot join it, but the record below documents what was studied.
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Hôpital Européen Marseille