has anyone tried Dr Nemechek Vagus Nerve?

[Cipher]

I wrote a post about VNS in another thread regarding its effects on GABA, thought it might belong in this thread as well:

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Vagus nerve stimulation seems to increase GABA in the brain. Here's a study that compared GABAa receptor density in people with epilepsy before and 1 year after the implantation of a VNS (vagus nerve stimulation) device. The VNS group had an increase of 42,5 % in GABAa receptor density and the control group had an increase of 7,6 %. This might only apply on people with epilepsy , but there are studies indicating a GABA enhancing effect in healthy individuals also (like this study; "SICI, a double-pulse TMS paradigm informative of GABA-A activity, was significantly increased in right motor cortex after real tVNS."). I've read that the anti-epileptic effects of VNS takes some time to manifest, so that might also apply to the GABA increasing effect. "Unlike drugs, where efficacy may decline with time, efficacy with VNS continues to improve over a period of 18 months to 2 years." (source)

"Regular" VNS is achieved using a neurostimulator that's surgically-implanted in the chest. An alternative, noninvasive form of VNS is called Transcutaneous Vagus Nerve Stimulation (tVNS), alternatively Transcutaneous Auricular Vagus Nerve Stimulation (taVNS). This can be achieved using a TENS/EMS machine and an ear electrode. VNS have also been shown to lower inflammation, for example in this pilot study with rheumatoid arthritis. I have myself just started experimenting with taVNS using a Beurer EM 49 and an earclip stimulating the tragus.

There is a couple of parameters that is relevant when it comes to VNS; current intensity, frequency (Hz), pulse width (μs), duty cycle (On/Off time) and session duration. NEMOS, which is a tVNS-device used for epilepsy, uses 25 Hz, 250 μs pulse width, 30s ON, 30 OFF duty cycle in 1 hour sessions, 4 sessions per day. This is a lot different from the parameters used in the rheumatoid arthritis study, where they used 10 Hz, 250 μs pulse width, 60 seconds per session, 4 sessions per day. 4 minutes instead of 4 hours! The field is still in its infancy, so parameters varies greatly and what's optimal is not known. According to this study lower frequencies (≤10 Hz) are better suited for anti-inflammatory purposes, and higher frequencies (20-30 Hz) are better suited for epilepsy and depression.

When it comes to current intensity it seems like what's the most common is to adjust the intensity to a bit above the perceptual threshold. Perceptual threshold means the lowest current that's noticeable. According to this paper 200 % of the perceptual threshold is appropriate.

Parameters used with epilepsy might be better for increasing GABA in the brain. I don't know if lower frequencies (≤10 Hz) increases GABA in the brain. Also as a side-note; because VNS stimulates the "cholinergic anti-inflammatory pathway", it might be prudent to combine this with an adequate choline intake, using choline bitartrate for example. But that's just pure speculation on my part.

 

[Avena]

@Cipher Cerbomed seems to have released a second device called Vitos - target group migraine. Do you have any info on the current/pulse etc there?

 

[Cipher]

@Cipher Cerbomed seems to have released a second device called Vitos - target group migraine. Do you have any info on the current/pulse etc there?

The VITOS device seems to use 1 Hz frequency (source), instead of 25 Hz that the NEMOS device uses. I haven't found any conclusive information regarding the other parameters, but I found this study which was funded by Cerbomed, which compared 1 Hz to 25 Hz in the treatment of chronic migraine:

During stimulation, series of electrical pulses (pulse width: 250 μs, frequency: 1 Hz or 25 Hz, duty cycle: 30s on, 30 s off, to avoid habituation) are applied to the skin of the concha. Stimulus intensity was individually fitted during visit 2 to elicit a tingling but not painful sensation, and could later be adjusted by the patient as needed. Patients were asked to stimulate for a total of 4 h per day (in sessions of 1 to 4 h, a specific distribution over the day or interval between sessions was not required), and were free to stimulate for an additional hour if they thought this was useful, e.g. for treatment of acute headache.

The VITOS device probably uses those parameters, which is the same as NEMOS except for the frequency.

 

[Avena]

Thank you, @Cipher, that was helpful.

How important do you find the tragus vs cymba conchae to be? The price difference on the Cerbomed products vs the alternatives is enormous...

 

[Cipher]

Thank you, @Cipher, that was helpful.

How important do you find the tragus vs cymba conchae to be? The price difference on the Cerbomed products vs the alternatives is enormous...

The science is a bit mixed regarding tragus vs cymba conchae. Most studies indicates that the tragus is a sutible stimulation target for tVNS, but one study indicated that the cymba conchae was superior compared to the tragus. Here's some studies I've found regarding this:

Neurophysiologic effects of transcutaneous auricular vagus nerve stimulation (taVNS) via electrical stimulation of the tragus: A concurrent taVNS/fMRI study and review.

Abstract
BACKGROUND:

Electrical stimulation of the auricular branch of the vagus nerve (ABVN) via transcutaneous auricular vagus nerve stimulation (taVNS) may influence afferent vagal networks. There have been 5 prior taVNS/fMRI studies, with inconsistent findings due to variability in stimulation targets and parameters.
OBJECTIVE:

We developed a taVNS/fMRI system to enable concurrent electrical stimulation and fMRI acquisition to compare the effects of taVNS in relation to control stimulation.
METHODS:

We enrolled 17 healthy adults in this single-blind, crossover taVNS/fMRI trial. Based on parameters shown to affect heart rate in healthy volunteers, participants received either left tragus (active) or earlobe (control) stimulation at 500 μs 25 HZ for 60 s (repeated 3 times over 6 min). Whole brain fMRI analysis was performed exploring the effect of: active stimulation, control stimulation, and the comparison. Region of interest analysis of the midbrain and brainstem was also conducted.
RESULTS:

Active stimulation produced significant increased BOLD signal in the contralateral postcentral gyrus, bilateral insula, frontal cortex, right operculum, and left cerebellum. Control stimulation produced BOLD signal activation in the contralateral postcentral gyrus. In the active vs. control contrast, tragus stimulation produced significantly greater BOLD increases in the right caudate, bilateral anterior cingulate, cerebellum, left prefrontal cortex, and mid-cingulate.
CONCLUSION:

Stimulation of the tragus activates the cerebral afferents of the vagal pathway and combined with our review of the literature suggest that taVNS is a promising form of VNS. Future taVNS/fMRI studies should systematically explore various parameters and alternative stimulation targets aimed to optimize this novel form of neuromodulation.

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Effects of transcutaneous vagus nerve stimulation in individuals aged 55 years or above: potential benefits of daily stimulation.

Ageing is associated with attenuated autonomic function. Transcutaneous vagal nerve stimulation (tVNS) improved autonomic function in healthy young participants. We therefore investigated the effects of a single session of tVNS (studies 1 and 2) and tVNS administered daily for two weeks (study 3) in volunteers aged ≥ 55 years. tVNS was performed using modified surface electrodes on the tragus and connected to a transcutaneous electrical nerve stimulation (TENS) machine. Study 1: participants (n=14) received a single session of tVNS and sham. Study 2: all participants (n=51) underwent a single session of tVNS. Study 3: participants (n=29) received daily tVNS for two weeks. Heart rate variability and baroreflex sensitivity were derived. Quality of life (QoL), mood and sleep were assessed in study 3. tVNS promoted increases in measures of vagal tone and was associated with greater increases in baroreflex sensitivity than sham. Two weeks of daily tVNS improved measures of autonomic function, and some aspects of QoL, mood and sleep. Importantly, findings showed that improvements in measures of autonomic balance were more pronounced in participants with greater baseline sympathetic prevalence. This suggests it may be possible to identify individuals who are likely to encounter significant benefits from tVNS.

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BOLD fMRI effects of transcutaneous vagus nerve stimulation in patients with chronic tinnitus.

Abstract
OBJECTIVE:

Vagus nerve stimulation (VNS) is a neuromodulation method used for treatment of epilepsy and depression. Transcutaneous VNS (tVNS) has been gaining popularity as a noninvasive alternative to VNS. Previous tVNS neuroimaging studies revealed brain (de)activation patterns that involved multiple areas implicated in tinnitus generation and perception. In this study, functional magnetic resonance imaging (fMRI) was used to explore the effects of tVNS on brain activity in patients with tinnitus.
METHODS:

Thirty-six patients with chronic tinnitus received tVNS to the inner tragus, cymba conchae, and earlobe (sham stimulation).
RESULTS:

The locus coeruleus and nucleus of the solitary tract in the brainstem were activated in response to stimulation of both locations compared with the sham stimulation. The cochlear nuclei were also activated, which was not observed in healthy subjects with normal hearing. Multiple auditory and limbic structures, as well as other brain areas associated with generation and perception of tinnitus, were deactivated by tVNS, particularly the parahippocampal gyrus, which was recently speculated to cause tinnitus in hearing-impaired patients.
CONCLUSIONS:

tVNS via the inner tragus or cymba conchae suppressed neural activity in the auditory, limbic, and other tinnitus-related non-auditory areas through auditory and vagal ascending pathways in tinnitus patients. The results from this study are discussed in the context of several existing models of tinnitus. They indicate that the mechanism of action of tVNS might be involved in multiple brain areas responsible for the generation of tinnitus, tinnitus-related emotional annoyance, and their mutual reinforcement.

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Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI.

Abstract
OBJECTIVE/HYPOTHESIS:

Vagus nerve stimulation (VNS) is an established therapy for drug-resistant epilepsy, depression, and a number of other disorders. Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) has been considered as a non-invasive alternative. Several functional magnetic resonance imaging (fMRI) studies on the effects of tVNS used different stimulation parameters and locations in the ear, which makes it difficult to determine the optimal tVNS methodology. The present study used fMRI to determine the most effective location for tVNS.
MATERIALS AND METHODS:

Four stimulation locations in the ear were compared: the inner tragus, inferoposterior wall of the ear canal, cymba conchae, and earlobe (sham). Thirty-seven healthy subjects underwent two 6-min tVNS stimulation runs per electrode location (monophasic rectangular 500 μs pulses, 25 Hz). General linear model was performed using SPM; region-of-interest analyses were performed for the brainstem areas.
RESULTS:

Stimulation at the ear canal resulted in the weakest activation of the nucleus of solitary tract (NTS), the recipient of most afferent vagal projections, and of the locus coeruleus (LC), a brainstem nucleus that receives direct input from the NTS. Stimulation of the inner tragus and cymba conchae activated these two nuclei as compared to sham. However, ROI analysis showed that only stimulation of the cymba conchae produced a significantly stronger activation in both the NTS and LC than did the sham stimulation.
CONCLUSIONS:

These findings suggest that tVNS at the cymba conchae properly activates the vagal pathway and results in its strongest activation, and thus may be the optimal location for tVNS therapies applied to the auricle.

Because it was easier to build a clip to stimulate the tragus I've only tested that as yet. I built one pretty similar to this one by Cort at Health Rising. I made mine using silicone electrodes that I attached to a clip with fishing line.

(The scotch tape is there to prevent short circuiting)

The connectors that originally came with the Beurer EM 49 doesn't fit these electrodes, but I found this cable that does:

The connector that goes into the Beurer EM 49 doesn't fit at first, but if you file the edges a bit it will fit without any problem.

I apply salt water at the skin before placing the electrodes, and reapply after a while when the moister evaporates. I've tried TENS gel but the one I tried was too slippery so the earclip didn't stay on the tragus.

I think it's possible to build something that works like the NEMOS ear electrodes to stimulate the cymba conchae, but it seems be a lot trickier than the tragus-clip.

 

[Avena]

I think it's possible to build something that works like the NEMOS ear electrodes to stimulate the cymba conchae, but it seems be a lot trickier than the tragus-clip.

@Cipher it looks like it is possible to buy the NEMOS ear electrode separately. But the plug seems quite hard to convert.

 

[Hipsman]

There is a couple of parameters that is relevant when it comes to VNS; current intensity, frequency (Hz), pulse width (μs), duty cycle (On/Off time) and session duration.

Do TENS machines support duty cycle (On/Off time)?

Also, is "current intensity" the same as "Pulse Amplitude: Adjustable, 0-100 mA" ? (written on TENS 7000's description page)?

I want to buy TENS 7000 as @anne_likes_red pointed out that Dr N used it, does it support duty cycles?

 

[Cipher]

Do TENS machines support duty cycle (On/Off time)?

Not all TENS devices support duty cycles, I'm unsure about the TENS 7000. The Beurer EM 49 supports duty cycles.

Also, is "current intensity" the same as "Pulse Amplitude: Adjustable, 0-100 mA" ? (written on TENS 7000's description page)?

Yes, mA is a unit of electric current.

 

[anne_likes_red]

Do TENS machines support duty cycle (On/Off time)?

Also, is "current intensity" the same as "Pulse Amplitude: Adjustable, 0-100 mA" ? (written on TENS 7000's description page)?

I want to buy TENS 7000 as @anne_likes_red pointed out that Dr N used it, does it support duty cycles?

Not using the continuous or "normal" mode there isn't.
We added a manual switch (restriction to the dial) to allow for something more like on/off. It restricted the power to a range from below detectable, ie: just short of "off" to comfortably detectable - approx 1.5 on the dial. I used this so I could apply the stimulation only on the outbreath.
Hope that makes sense.

 

[Hipsman]

Not using the continuous or "normal" mode there isn't.

Yea, I checked some user manuals, it appears that only EMS have such setting, so TENS & EMS Combo Unit is needed. I am looking at buying this one, it has Adjustable 1~60 seconds duty cycle (page 17). Duty cycle info, if present, available in "Technical specifications " part of user manual.

 

[ItoldthemIwasill]

Not all TENS devices support duty cycles, I'm unsure about the TENS 7000. The Beurer EM 49 supports duty cycles.


Yes, mA is a unit of electric current.

So Cipher how have you got on with the VNS?

I have been using a continuous Med Fit 3, and am looking for something with cycle so I can wear for longer without it getting too much... How have you found the Beurer EM49? It is the only one I have found, apart from the Neurotrac Sport XL (which is a lot bigger I think), with a Tens Duty Cycle... SO I am interested as to how you found it.

And incidentally, I have been using the Tens with great benefit I believe, so I am keen to optimise my use of this.

I am also trying to fabricate a better ear clip solution. I really want something more comfortable. Using on the concha (which I read is the best place) can become painful after an hour. And as I am using it really as a crutch and using for 5/6/7 hours a day, I'd like something a little more discreet. I am experimenting with plastic moulding at the moment.

And also interested in a way of using it overnight too.

 

[ItoldthemIwasill]

Yea, I checked some user manuals, it appears that only EMS have such setting, so TENS & EMS Combo Unit is needed. I am looking at buying this one, it has Adjustable 1~60 seconds duty cycle (page 17). Duty cycle info, if present, available in "Technical specifications " part of user manual.

Did you make any progress with this Hipsman? Ive had a look and that model you were looking at isn't available in the UK, so Im looking at the Beurer...

 

[ItoldthemIwasill]

Not using the continuous or "normal" mode there isn't.
We added a manual switch (restriction to the dial) to allow for something more like on/off. It restricted the power to a range from below detectable, ie: just short of "off" to comfortably detectable - approx 1.5 on the dial. I used this so I could apply the stimulation only on the outbreath.
Hope that makes sense.

Hi anne_likes_red, I read this topic with interest a few months ago and it inspired me to pick up my Tens again, and try to create a better earpiece... (I had used this several years ago, but found it was giving me headaches and I gave up. I think it was your advice to turn the frequency down) I understand that the Parasympathetic system becomes more dominant on the outbreath, so I can see why you are looking to bring it on and off in that way, but how is that working? I am using it more as a daily crutch as it allows me to be more active, and gives me more capacity, whereas it sounds like you are using it more for a therapeutic use, kind of in the way one might for meditation or yoga??

 

[Hipsman]

Did you make any progress with this @Hipsman?

I'm only about to order it...

Edit: just ordered this.

Ive had a look and that model you were looking at isn't available in the UK, so Im looking at the Beurer...

It says in checkout process that it will ship to Ukraine, so it's weird if it doesn't ship to UK from tenspros.com

 

[ItoldthemIwasill]

I'm only about to order it...
View attachment 36298

It says in checkout process that it will ship to Ukraine, so it's weird if it doesn't ship to UK from tenspros.com

Im sure it would, I suppose the Beurer is shipped from within UK, so a bit easier/cheaper to get hold of. And the cycle seems similar for both too. Good luck with it, I am finding it actually mega mega helpful, and using it at the maximum levels recommended.

 

[Cipher]

So Cipher how have you got on with the VNS?

I used it for a while, and my symptoms tend to go very much in cycles up and down, so it was hard to evaluate the effect. After reading about the vagus nerve infection hypothesis I decided to pause the testing until I've ruled out any infectious origin of my symptoms, as I'm unsure about the safety to stimulate a theoretically infected vagus nerve.

 

[anne_likes_red]

Hi anne_likes_red, I read this topic with interest a few months ago and it inspired me to pick up my Tens again, and try to create a better earpiece... (I had used this several years ago, but found it was giving me headaches and I gave up. I think it was your advice to turn the frequency down) I understand that the Parasympathetic system becomes more dominant on the outbreath, so I can see why you are looking to bring it on and off in that way, but how is that working? I am using it more as a daily crutch as it allows me to be more active, and gives me more capacity, whereas it sounds like you are using it more for a therapeutic use, kind of in the way one might for meditation or yoga??

I've read some criticism of tvns protocols that use very long periods of a continuous stimulation. Some studies indicated the brain may switch off completely to tvns if it's administed continuously for hours.
I guess I am more using it to enhance breathwork. Prior to using electrical stimulation I tried manaual stimulation of the vagal dermatome on the outbreath and I felt I had some good results from this.
I used to have a 'panic response' if I tried to extend my exhale, so although it's very much improved - a confident extended outbreath is still work in progress for me. There is an application of t-vns called called e-ravans where the stim is applied on the outbreath only. I believe I have read of this intervention being used in a study with war veterans with ptsd. The equipment needed is more complex than the TENS units I've seen for sale. So, I just turn the dial up and down with my breath. We put something to serve as stoppers at either end of the range I need to use, so I can't either turn the unit off or zap myself by mistake.

 

[Hipsman]

I was curios to see what is the max μs for hand-held TENS unit, highest I could find is 600μs. All 600μs devices cost much higher then 450μs, there was also a cheap 500μs (HYS-666) unit. Wondering if the μs range is just locked on software level, or to achieve higher μs requires a better TENS unit?

So, does the manufacturer decide the μs range basted on what the device can actually achieve with stability, or is it just their decision to lock μs at a specific value?

 

[Hipsman]

WoW! I found a cool video tutorial-study on how to do taVNS as a researcher! It gives insight to important details that were not discussed on forums!

Specifically, This bit is interesting

Connect electrode cables to the stimulation device while the device is turned off and verify the polarity of the electrodes (red/positive electrode: anode, black/negative electrode: cathode). This is an important detail as targeting is polarity specific — the anode (red/positive terminal) is the electrode placed inside the ear canal and targeting the anterior wall of the outer ear canal. The cathode (black/negative terminal) sits on the outside of the ear attached to the tragus. For sham stimulation, the anode is placed on the anterior side of the ear.

And indeed, the lead wires for TENS unit have "+" and "-" singes for anode (red wire) and cathode (black wire) accordingly.
So make sure the red wire goes inside the ear where the tragus is, the other way around gives a shad stimulation (passive)!

I added the video, paper & all resources as an archive to Google Drive in case the tutorial gets taken down.

 

[Hipsman]

Also, if you ran into situation when, for example, 2mA is lower then perceptual threshold and 3mA is uncomfortable, tweak μs to increase or decrease perceptual threshold, as shown is the tutorial-study.