Welcome to Brainhub Podcast where you will discover the top news and tips on keeping your brain healthy.

Hello and welcome to the Brainhub Podcast my name is Matthew Holmes and with me today is Dr. Carlo Rinaudo a chiropractor and the owner of Brain Hub Clinics in Sydney.

Matthew: G’day Carlo, how are you doing?

Carlo: G’day Matt, glad to be here.

Matthew: You sound you are a bit under the weather I believe it was a fairly big weekend in terms of some conferences that you were speaking at and so forth.  Apologies to the listeners today, Carlo was saying he is a bit bunged up, but you want to tell us a little bit about what you have been up to and what has been going on?

Carlo: Yes, thanks Matt.  I apologise to the listeners to my very nasal and stuffy voice.  It has been a busy few months, most our listeners are aware that I have been presenting a series of seminars to practitioners across Australia on the vestibular and balance therapy which has been extraordinarily well received and we still have got some more planned for Perth, and Tasmania as well which is fantastic.  But over the weekend I was very fortunate to present to several hundred people practitioners, patients and parents at the international forum held by MINDD which is a rights initiative, it has been around now for about ten years, set up to help parents and adults and children and practitioners learn more about various chronic and nutritional, metabolic, immune, neurological and development disorders that unfortunately plaque many of us.

Matthew: Indeed.  What did you chat about when you were speaking there?

Carlo: I was very fortunate to be part of the teaching of a faculty there over the weekend.  My talk was on a problem that most people there were very familiar with which relates to gut function.  The direction which I took this was quite different than what most people are probably used to or exposed to.  My talk was on a brain based or a top down approach in helping people’s gut function, immunity and inflammatory conditions.  Whereas most of them have been exposed to very directed care to the gut through naturopathic or integrated medicine or other forms of health structures in getting the body to work to help the body, whereas my talk was get the brain to work better to help the gut to work better.  And it was quite novel for a lot of them and it was really well received.  I had a lot of parents and practitioners come up to me afterwards and share their thoughts and they were quite pleased that there was a different approach to problem unfortunately suffer from.

Matthew: Yes, it’s a very common problem these days unfortunately.  What you are saying is a bit of a great segway into today’s topic which is we are looking at vagal stimulation for the treatment of brain disorders and other disorders within the body.  This isn’t a topic that I know much about so I am actually very interested to hear what you have got to say as I am sure our listeners will.  Do you want to start by maybe giving us an overview of what the vagus nerve is, where it’s located etc?

Carlo: Before I get to the vagus nerve I will take a step back and talk about a part of the brain which the vagus nerve originates from, it’s called a brainstem, within this brainstem are many control centres and they record the autonomic nervous system.  There are many nucleo parts of the autonomic nervous system that sit within the brain stem.  The autonomic brain stem in itself is divided into two parts, there is sympathetic, that brain that helps coordinate our body and our response when we are under stress or when we are under attack and that’s very important and equally important is the flipside to that which our parasympathetic, our parasympathetic system is involved with our rest and digest, it’s involved with the part of the body that helps us to recover, repair, it helps digest foods, it helps us think, so it’s really the antagonist to the flight and flight the rest and digest.  That parasympathetic portion of the autonomic nervous system is controlled by the vagus nerve.  I need to step back a little bit to talk about the vagus nerve and I think with that in mind it’s pretty a little easier for us to discuss.  The vagus nerve is actually a cranial nerve so it’s one of the twelve cranial nerves that come out of our brain and supply various parts of our face and body.  So this cranial nerve, the vagus nerve is often referred to as the wondering nerve because in fact I think it’s the longest nerve in our body because it comes out of our brainstem, that lower part of the brain almost near where ears and top part of the neck would sit and it runs down through the neck into the torso and it supplies our hearts, it supplies our bronchial tubes, it supplies our guts.  The vagus nerve its job is to slow down heart rate, to slow down our breath rate, it’s also there to increase our gut function.  So it helps gut motility which means we can move matter through our gut effectively and quickly. It also supplies a lot of our organs which include our pancreas, our gull bladder and other parts of the digestive track to produce enzymes.  People are unaware enzymes are needed to break down food. So our vagus nerve helps organs to secrete enzymes which help break down food.  That’s pretty important for us to survive and to be able to absorb the all the nutrients that we need.  Another function it does is it supplies the lining of our gut.  In the lining of our gut we have got two important things, we have got a lot of our immune system which is why a good healthy gut not only equates to a healthy immune system but also the vagus nerve supplies the cells on the lining of that gut that helps keep them together.  It’s really important so our gut doesn’t become leaky and undigested, unbroken down foods are not allowed to be absorbed into our bloodstream.  So if you have good vagus activity the epithelium or the lining of that gut is tight and none of the undigested food is allowed to be absorbed into our bloodstream, which is really important.  So the vagus nerve is really really important and interestingly also it’s described as a bidirectional nerve meaning it sends information from our brain down to our organs but equally it’s sensory which means it detects what’s going on in our organs and tells our brain what’s happening.  So it also detects different problems and stresses in our organs and let’s our brain know hey say something is wrong we need to do something appropriate to make sure that it works well.  So it’s one of those incredibly important nerves in our body and research is now showing the value of understanding it in the therapeutic window that it has to offer as well.

Matthew: Yes, I remember reading a paper that was talking about if there is damage to vagal function that you lose your gut lining very quickly, is that correct.

Carlo: Yeah, it is. Some of the research that has been produced recently has linked poor vagus nerve activity with leaky gut syndrome, with irritable bowel syndrome, with chronic inflammatory bowel disease and there are many people out there that unfortunately suffer from these condition and I am pretty confident they are not getting a brain based approach a vagal nerve approach to help in the gut work. They are attending to it by getting some herbs or some nutritional products for their gut, they may be seeing a gastroenterology to help repair whatever is going on inside.  I am not going to take away from the value of that but equally that may only be a symptom to the brain not working particularly well.  The talk that I gave to two hundred and fifty plus people I hope sparked that thought pattern that oh maybe I should look at the other component to my gut which the top down the brain based effects and then that could be a nice adjunct to what I am currently doing.  So I think that many people were pleased and took that away.

Matthew: What you are saying is there are a number of conditions that can benefit from this.  How would somebody know that they might have vagal problem that’s causing it and is it the case that everybody with irritable bowel syndrome would be a potential candidate for this treatment and if so or if not what would give them some clues that maybe they need to look into this further?

Carlo: What I would often say to people is it really depends on what your examination and your assessment findings are.  So examinations or assessments that you could do to find whether or not your vagal tone is low or you have asymmetry in your autonomic nervous system.  Unfortunately there is no blood tests I think at the moment, cortisol level which is a salivary test that can look at what one of your stress hormones and that relates to your sympathetic systems.  So remember if your sympathetic system is high, unfortunately in the life that we lead, we tend to lead a very sympathetic dominant state.  So things like cortisol levels will tend to reflect that and if that’s high you could almost be safe to say that your vagal tone is going to be low as a by product of that.  Symptoms and history are the hallmark of any assessment, so any skilled practitioner should be able to ascertain that they get a good sense of where you are at based upon detailed history and examination.  But one of the, I guess the gold standard to determine autonomic dysfunction is heart rate variability where we are not just looking at your heart rate of 55 beats per minute but we are looking at the variability and most people will be quite surprised to hear the variability in your heart rate you can measure with an ECG machine or you can measure with a low cost, low tech device that you can put on your finger or as a chest strap and you can measure the variability in your heart rate.  Like this is a good idea whether you are sympathetic or para-sympathetic dominant.  Remember the vagus nerve is a by-product of the para-sympathetic nerves.  Additionally there are examinations we can look at, one is gag reflex, so the vagus nerve supplies the back of the throat, so we can look at how the throat functions when we will stroke it to elicit gag reflex whether it’s there, whether it’s asymmetrical, whether the left side or the right side works better.  We also look at other autonomic nerve system signs like pupil size is another classic sign or an autonomic imbalance.  For instance with a sympathetic or a fight or flight state our pupils are typically large, when we are in a rest and digest state our pupils are typically low.  So we may see that asymmetrically as well through the use of an ophthalmoscope.  We may look at the difference in size of the vein to artery size in the back of the retina.  We can look at other measures of brain function that give us an idea of what control do they have on the brainstem.  So I wouldn’t say it’s a simple question to answer but a detailed and thorough assessment will always give you the best way to detect if there is a problem and then from that the practitioner should then be able to tell a specific prescribed program based upon those results to help alleviate and manage those symptoms and that’s something that we do in our office all the time.

Matthew: Right, so when you are talking about putting together a protocol what sort of thing is involved in vagal stimulation, is it an electrical thing or do you do reflex stimulation or how does it work?

Carlo: There is a three pronged attack for us, we first we look at the higher brain because the higher brain has a huge influence on the brainstem.  So we want to make sure that the rest of the brain is doing well because without it, if there is an injury like a concussion or anthology like stroke, cerebral palsy or there is just a lack of attention and focus in the brain, it’s going to have a negative on the vagus nerve and other parts of the brainstem.  Firstly we want to make sure that those areas are working well, that’s for another discussion in itself, but in terms of the vagus nerve there is another two ways which we help, one is an in office program of using a specific current that we apply to the outer ear and the outer ear is one of the only part that the vagus nerve actually has in contact with the skin the rest of it’s obviously very deep.  And whilst there are invasive techniques that attach a pacemaker inside the body, clip a little stimulator on the nerve and that’s something that we do in our office and certainly then people have that but there is a transcutaneous or a surface mounted electrode that can be attached to one’s ear with a specific device we can use to apply very gentle and light constant current that can directly affect that vagus nerve.  And our clinic doctor has been really favourable to helping people with a number of different conditions with this particular device.

Matthew: Right, because I was going to say are there ways of going about it but it’s not necessarily something that you want to rush in and start doing vagal stimulation itself, you can look at the whole brain in its context.

Carlo: Certainly, like anything else I think the success of what you do will always depend upon the accuracy of what you are trying to do.  I try and apply cookbook approach to something that’s off the shelf and apply it, it will give like its results but I often say to people if you are going to spend some time and effort on something do it properly, get some proper direction.  The stimulator in the brain based therapy are things that we provide in our office and certainly we do it with a program, additionally we also prescribe some homework to people to do and there are some great home based vagal nerve exercises that are great as an adjunct to what we provide, please understand that it’s an adjunct.  There is little harm in trying to do it but the success of it, I haven’t seen as good unless you can combine it with other modalities.

Matthew: Right, so when you are you looking at that what types of things are you doing, is it things like gargling and so forth?

Carlo: Definitely, I think gargling is actually one of the best vagus nerve exercises that you can do.  It’s something that we encourage a lot of our patients to do. It’s advisedly the things that we recommend which include blowing a balloon, sucking through a straw or chewing food and gargling. When we recommend these things to people invariably they say ah I can’t do that, I choke on food or I can’t blow up a balloon or I gag on food because when it hits like my throat I just choke on it.  It’s exactly these people that this sort of therapy can be extraordinarily beneficial, in fact we work with a lot of children in collaboration with speech pathologists, speech pathologists often note that their abilities to use their tongue and mouth when they enunciate and pronounce letters and words is vastly improved when they have had some vagal nerve exercises and stimulation because now they their throats and their tongue and their back of their throat are all are working better.  So it has many flowing effects and it’s something that feature pretty strongly in our office.

Matthew: It makes you wonder then the people who are snorers and have sleep apnoea and so forth all to do with low muscle tone in the throat, has there been much research done of that aspect of it?

Carlo: It’s a great question I do have some patients with sleep apnoea that I have work with some holistic dentist that’s still in progress.  We are just looking for subtleties in the presentation that may give you better real results but in theory it makes sense, it makes sense that when someone sleeps they have poor throat tone which is vagus nerve and as a result their voice box and their throat you can get that sound that occurs as air passes through, the turbulence can be heard of as gaggling or very throaty sound or even a snoring.  So I have not seen any data on it, I would be curious to follow that up but in theory it does make sense.

Matthew: One thing that I have heard about with vagus stimulation is using it from a brain plasticity point of view, is that something that you really sort of factor in do you into your equation or is that something that you haven’t looked into so much.

Carlo: So what I have discussed so far is probably more than input into the brainstem and down into the rest of the body but equally understand that there is never a one single direction path, it always goes different directions.  So once we stimulate the brainstem through the vagal nerve stimulation or during our exercises you will always have an upward effect to the rest of the brain.  So what we find is those that have fear, anxiety and even depression and the research has shown this, and I can talk about that in a moment, that if we can stimulate the vagus nerve it has been shown to actually help alleviate a lot of the symptoms that are associated with some of these conditions.  It allows us in our office to provide additional care or adjunctive care to help with some of their other concerns.  So whilst I am certainly not saying this is going to cure their depression or their anxiety it certainly gives us a platform to be able to give better leverage in providing a care to other parts of the body but the research is also saying that it may actually have more of a direct effect and what I see in my office as well.

Matthew: Well, that’s very interesting, if somebody wants to get help with this type of thing, what should they do?

Carlo: Our office we are certainly taking and seeing patients with these sorts of conditions or symptoms of these conditions and they include children, adults and we always start with a comprehensive examination on where and what the problem is and we feel that the best person or at least part of the team that can help them we certainly make that recommendation.  If we feel that the condition is best assessed by someone else then we also make that call.  But I think it’s an area that’s often overlooked, it’s an area that’s now getting more traction and people are starting to see that the vagus nerve is an incredible window to helping various parts of the brain.  If I may just take a moment to highlight some of the research that’s coming out at the moment.  I think initially vagal nerve stimulation was shown to be very effective with people with seizures and help reduce the intensity or frequency of seizures and that has been well documented for some years, depression, chronic pain, inflammatory disorders like the subtleties disease and rheumatoid arthritis.  Its effect is becoming more substantiated in research and in clinically in our office we are seeing it more and more.  So I think almost no matter what condition someone presents to our office with is something that we certainly look at and it might well be part of the program of care.

Matthew: That’s very interesting and particularly the whole epilepsy aspect and so forth.  Well that really wraps up what we are going to talk about today, I mean it’s always great to sort of look at this cutting edge treatments and see how they can be applied but is there anything you would like to mention in closing Carlo?

Carlo: I think the main point I want to talk about is look at the brain, just because you may have symptoms in other parts of the body it doesn’t necessarily mean that that’s where the problem is.  So I encourage people to work with people that have a very holistic approach, a very integrated approach to healthcare and the work that we do at our office in our Brain Hub Clinics certainly is a reflection of that and I guess my studies in neuroscience and a PhD in neuroscience is a testament that understanding how the brain operates will give people hopefully more answers and more solutions to the health problems.  So call into our office to register on our website or our phone number and we are happy to have a chat with you as to how we could help you.

Matthew: That would be good as always if anybody has any questions that they want to ask about what we have covered today it will be on what Carlo has just mentioned pop along to brainhub.com.au/blog and post your questions below today’s episode, we will more than happy to pop in there and answer those and you can contact the practice by calling 1300 770 197 or by using the contact details on brainhub.com.au particularly if you are outside Australia, I believe that number only works if you are inside Australia.

Carlo: That’s correct yes.

Matthew: That’s correct, don’t worry, that’s the trouble with this 1300 numbers but we have got plenty of contact information on the website.  If you like the work that we are doing on the Brainhub Podcast do leave us a four or five review on iTunes or your favourite podcasting platform but until next time take care.


Thanks for listening to the Brainhub Podcast, for more information and to subscribe visit brainhub.com.au.


1: Liu J, Fang J, Wang Z, Rong P, Hong Y, Fan Y, Wang X, Park J, Jin Y, Liu C,
Zhu B, Kong J. Transcutaneous vagus nerve stimulation modulates amygdala
functional connectivity in patients with depression. J Affect Disord. 2016 Aug

2: He B, Lu Z, He W, Huang B, Jiang H. Autonomic Modulation by Electrical
Stimulation of the Parasympathetic Nervous System: An Emerging Intervention for
Cardiovascular Diseases. Cardiovasc Ther. 2016 Jun;34(3):167-71.

3: Cha WW, Song K, Lee HY. Persistent Geotropic Direction-Changing Positional
Nystagmus Treated With Transcutaneous Vagus Nerve Stimulation. Brain Stimul. 2016

4: Trevizol AP, Shiozawa P, Taiar I, Soares A, Gomes JS, Barros MD, Liquidato BM,
Cordeiro Q. Transcutaneous Vagus Nerve Stimulation (taVNS) for Major Depressive
Disorder: An Open Label Proof-of-Concept Trial. Brain Stimul. 2016
May-Jun;9(3):453-4. doi:

5: Holle-Lee D, Gaul C. Noninvasive vagus nerve stimulation in the management of
cluster headache: clinical evidence and practical experience. Ther Adv Neurol
Disord. 2016 May;9(3):230-4.

6: Frøkjaer JB, Bergmann S, Brock C, Madzak A, Farmer AD, Ellrich J, Drewes AM.
Modulation of vagal tone enhances gastroduodenal motility and reduces somatic
pain sensitivity. Neurogastroenterol Motil. 2016 Apr;28(4):592-8.

7: Schoenen J, Roberta B, Magis D, Coppola G. Noninvasive neurostimulation
methods for migraine therapy: The available evidence. Cephalalgia. 2016 Mar 29.



Dr Carlo Rinaudo (Chiropractor and PhD candidate) is the clinic director of Brain Hub, a clinic in Sydney focussed on helping people with dizziness and vertigo conditions, poor balance, whiplash and concussion symptoms.

The clinic and its practitioners use a range of modalities to help assess and manage these conditions and/or symptoms. Vestibular rehabilitation therapy and other brain-based therapies are primarily utilised, along with standard Chiropractic and physical therapy techniques.

The growing evidence showing support for the management of these conditions comes primarily from the physical therapy and clinical neuroscience fields, rather than chiropractic specific. Fortunately, Dr Rinaudo with post-graduate training both in Australia and from overseas is experienced to translate this knowledge into clinical practice. Additionally, he is currently undertaking a PhD from the University of New South Wales (UNSW) and Neuroscience Research Australia (www.neura.edu.au) in Vestibular Therapy, more specifically clinical trials on how to help people with dizziness and vertigo conditions. He is working alongside leading researchers and Neurologists in the field. Additionally, the benefits expected from his PhD research will be used to further validate the use of vestibular rehabilitation therapy for other related conditions like whiplash and concussions.

Dr Rinaudo is a frequent speaker at national events, as well as lecturer in the field of vestibular rehabilitation and dizziness conditions to other health practitioners.