I have been exploring use of the noninvasive vagal nerve stimulation in the clinic in the form of an ear electrode in the cymba concha region. There doesn’t seem to be any good reason to use one side versus another. In invasive vagal stimulation, the left side is used to avoid efferent side effects. In indirect vagal stim, as I am using, this isn’t necessary since we are stimulation afferent vagal activity in an effort to stimulate brain regions.
Below is a data set from a healthy woman who suffers from severe PMS. Acupuncture eases her symptoms so she comes in for two visits before her cycle every month. She likes and can stand robust needling so was a great candidate for the ear stim device. The ear stim sessions are indicated by the black arrows, the needling segments are in dark blue.
It’s pretty hard to make the case that the ear stim is having a big effect on her stress profile during treatment. On the other hand, it doesn’t seem to be causing an arousal response either. As in the patient below.
The patient below noticed that she didn’t get the same degree of relaxation with the ear stimulation device as with treatment without the ear stim device.
It’s pretty difficult to see much of a difference with the ear stim device. There is a bit more “noise” during treatment, meaning that the stress levels fluctuate. But other than that, not too much to see.
So in sum, I’m not too convinced by the utility of the ear stim device in all patients.