POTS Page 5

  In making this connection between the limbic system in crisis and the malfunctioning of the NET protein, I am trying to ‘connect the dots’. If NET is deficient in POTS patients, and we know that it is, and if this is not the result of genetics, which we also know that it is not, then, surely, the only adequate explanation is that NET has become deficient through the excess supply of adrenalin, and that the root cause of this can only be found in the brain, and in particular the limbic system? I cannot see any other reason for NET having become deficient. It cannot, for example, become deficient through cardiovascular weakness (for in that case most of the elderly would have NET deficiency). For the same reasons, I cannot see any other reason why the POTS patient should be ‘hyperadrenergic’, other than the limbic system entering continuous crisis along with the frequent release of adrenalin which that entails.

  Furthermore, this theory I am putting forward takes very seriously the idea that POTS is preceded by a triggering event. You will remember in chapter one that I outlined the mainstream view that POTS nearly always is preceded by a triggering event, but that the connection between such an event and the onset of the condition has not been studied. Nevertheless, it seems to be a constant that can be observed and as such it must hold the key to the condition. It is rare, if you read a story about how someone developed POTS in the media for example, that you do not also read of some kind of antecedent illness. There must be a reason why this is the case. I believe that it is because the antecedent illness is so severe that the distress signals the body emits to the brain during the course of that illness force the limbic system to enter a state of hardwired neurological crisis. Furthermore, it should be noted that all kinds of antecedent illnesses seem to lead to POTS. I have used mononucleosis and Lyme disease as my main examples but one reads of many different preceding illnesses from bacterial infections to salmonella poisoning. The fact that there are a variety of possible ‘triggering’ illnesses shows that their significance is to be found in the severity of the illnesses in question: that is their common link. In other words, it would be misguided to think that there may be something specific in mononucleosis (rather than Lyme disease, say) that holds the key to understanding POTS or vice versa. Rather the key thing is that both illnesses - and all others which trigger POTS - tend to be severe. It is this severity which explains why the brain is adversely impacted by such illnesses.

  I hope that this chapter will have shown that the fact that there is a triggering event is not merely a side point, but the key to the whole condition and something which illustrates that the condition clearly stems from a brain impairment.

  Conclusions I: From POTS to LSIND

  In summary, POTS could be better defined as the following:

  “A state of hard-wired “trauma” in the limbic system from a triggering event where trauma is understood broadly to include physical traumas such as a viral illness. This state of hardwired trauma leads to the release of continuous crisis signals via the HPA axis (including the frequent release of adrenalin) which leads, in turn, to NET deficiency along with deficient vasoconstriction, a hyperadrenergic state, and resulting tachycardia as a result of this deficient vasoconstricion and increased adrenalin. This limbic system dysfunction also leads to a wide range of problems in the nervous system, affecting digestion, the hormonal and endocrine systems, energy production and sensory perception in the limbic system, with increased sensitivity to light, sound and smell.”

  In other words, POTS is not primarily a cardiac problem: it is a neurological one with widespread effects on the entire body. Given this, what should the condition really be called? I would suggest that a more accurate name might be LSIND or ‘Limbic System Induced NET Deficiency’, as that covers the key neurological and cardiovascular problems in the condition, and the relation of the one to the other.

  There are, of course, advantages to using the term ‘POTS’ to describe the condition, primarily because this term has now been used for quite some time and considerable awareness has been raised about the condition. In other ways, however, POTS is an unhelpful term in that many do not grasp the significance of the ‘S’ or ‘Syndrome’ part of the acronym, and actually define the condition as being a problem with ‘dealing with gravity’. I believe that calling this condition ‘POTS’ has meant that its seriousness has not been fully grasped. It is easier not to grasp the severity of the condition if it merely seems to involve problems standing up, a fact that has led some to call it merely a ‘nuisance’ condition (although I would challenge anyone who says this to stand by the idea that being unable to stand up without difficulty is merely a ‘nuisance’!). There is another problem with the term ‘POTS’ in that it places too much emphasis on the idea that the condition is primarily postural. Now, of course, as we know, the patient is indeed particularly affected upon standing up for that is when the NET protein must do its primary work. But that is just a side-effect of the actual root cause of the condition, which is a form of neurological impairment. Indeed, although it is essential that the POTS patient understands the difficulties she will face upon standing, it is misleading to define the condition as being a problem with standing up. After all, if the theory I am putting forward is true, this is happening only as a knock-on effect of an ongoing neurological crisis.

  I note that the other term used for the condition, ‘dysautonomia’ is undoubtedly more accurate than POTS. However, it too gives a somewhat false impression. Why? It leaves out the limbic system, which is the root of the nervous system. Indeed, it gives the impression that the nervous system has gone into crisis “of its own accord”. To the patient, ‘dysautonomia’ has a cruel finality to it: my nervous system has gone haywire and there is nothing I can do about it. This description ignores, however, the scientific fact that the nervous system takes its ‘cue’ for how to behave from the ‘signal’ it constantly receives from the limbic system: it does not act “of its own accord” and it certainly does not go into crisis for reasons known only to itself.

  Conclusions II: POTS is Caused by the Brain But it is Not Psychosomatic

  It should be obvious from the discussion in this chapter that to say POTS is caused by limbic system impairment is not to suggest that it is psychosomatic. A psychosomatic illness has negative (and often deeply misguided and prejudiced) connotations attached to the term which suggest that some people can ‘think themselves into’ a state of illness. Leaving aside the question of whether this is even biologically possible, it certainly does not apply to POTS. Rather, something overwhelmingly terrible happens, such as a viral illness, and the limbic system perceives this to be so threatening to the organism’s survival that it rewires itself of its own accord into a hard-wired protective and crisis state. The limbic system is a primitive part of the brain and it does this in automatic ways which the individual concerned has no say in. Even if the initial trigger is a psychological one, as can be the case, the individual has no say in this either as the limbic system also acts automatically and of its own accord in these cases too (as is the way in PTSD also). So there should never be any fault or blame imputed onto the patient with POTS. In the same way that a war veteran with PTSD should never be ‘blamed’ for how his or her primitive limbic system reacted to the horrors of war, so too should a POTS patient not be blamed for how his or her primitive limbic system reacted to an antecedent ‘triggering’ traumatic illness or other trauma.

  Indeed, I believe that there is an understandable fear amongst patients and medical researchers alike that the condition might ever appear to be ‘psychosomatic’. This is understandable as a) it is plain wrong to regard POTS as such and b) it would falsely stigmatise those suffering with this devastating condition. However, the efforts to avoid the psychosomatic label may have led POTS research away from where it needs to go. For example, the fact that there is extra sympathetic discharge in POTS patients appears to be well-known but there has been - perhaps - an unwillingness to consider the role of the brain in emitting this extra sympathetic
discharge because that might appear - on the face of it - to imply that POTS is a psychological problem, no different from an anxiety disorder. Instead, research has focussed on NET deficiency as being the key reason for the extra adrenalin that exists in the POTS patient’s blood stream, not realising that NET has probably become deficient in the first place because the brain is in crisis. Whilst this fear is understandable, I hope I have shown it is also misguided. For the limbic system in the case of POTS is not the same as the limbic system in a state of (psychological) anxiety. There is more than one way for a limbic system to enter a crisis, and the limbic system is not just affected by psychological traumas, as I have pointed out, but also by the body-mind connection and the kind of ‘distress’ signals the limbic system can receive during a severe illness. If the significance of this could be grasped then I think there would not need to be any fear of the condition ever being falsely labelled as ‘psychosomatic’. Furthermore, it needs to be remembered that the limbic system is primitive and responds automatically to events following its own laws such that even in the case of crushing psychological triggers, these too are not the ‘fault’ of the individual concerned. However, we are culturally myopic about both of these aspects. As regards the former, we have little awareness of how the brain can be affected by signals coming from the body and, as regards the latter, many - almost always those who have not experienced a trauma themselves - do not understand the ways in which the brain can be affected by events. For example, it’s easy for the person without PTSD to tell someone who has it to ‘snap out of it’, but that person simply has no idea what suffering with a limbic system impairment is like. For when the limbic system is calm, you don’t notice its workings. When it is in crisis, however, its immense power and huge role in our overall physical and psychological health become overwhelmingly apparent.

  Key Points of Chapter Two

  In this chapter, I have set out the theory that it is possible for the limbic system to enter a perpetual crisis state following an initial trauma, broadly understood. I have put forward an hypothesis as to how this perpetual crisis state can explain the core findings of those with POTS: a hyperadrenergic state and NET deficiency. The limbic system in crisis leads to the constant release of adrenalin which, in time, leads the NET protein to break down. You cannot do push ups for ever and nor can the NET protein do its job forever of recycling available adrenalin. Based on this, I suggest the condition might instead be more accurately termed LSIND: ‘Limbic System Induced NET Deficiency’ and that any reference to it as ‘dysautonomia’ should also recognise the role of the limbic system in the autonomic nervous system.

  Further Reading

  Hopper, A., Wired for Healing: Remapping the Brain to Recover From Chronic and Mysterious Illnesses, Friesens, 2014.

  Chapter Three: Explaining the Whole Elephant (or How Limbic System Malfunction Can Explain Everything We Know About POTS)

  In the introduction, we first considered the elephant analogy used by Prof. Satish Raj, a researcher on POTS at the University of Calgary. Several blind men are each holding different parts of an elephant. As they only focus on parts of the elephant however, they cannot grasp the whole of the creature, and so they do not realise that they are, in fact, holding parts of an elephant: they make incorrect guesses as they are unable to see the big picture. I believe this analogy holds true. In this chapter, I will suggest how understanding the condition as a limbic system impairment could arguably explain all the various so-called ‘POTS sub-types’ or how, in other words, understanding the neurological origins of POTS can explain the ‘whole elephant’. Furthermore, the idea of limbic system impairment can also potentially explain other overlapping conditions that the POTS patient often has, such as chronic fatigue syndrome (M.E.) and fibromyalgia. Having said that, the explanation of NET deficiency as having been caused by a limbic system impairment remains this book’s most important potential contribution as NET deficiency is the principal reason the POTS patient’s heart rate increases upon standing up (as a result of vasoconstriction deficiency).

  The Misplaced Idea of POTS ‘Subtypes’

  In my view, it is a mistake to hold too rigidly to the idea that there are separate kinds of POTS, or ‘POTS subtypes’. The usual story of POTS subtypes goes something like this: you have either the ‘hyperadrenergic’ form of POTS, the ‘deconditioning’ form, or the ‘neuropathic’ form. In addition, there are also other potential subtypes: the POTS which co-exists with viral antibodies, or the POTS which is caused by having defective collagen production (as found in Ehlers-Danlos Syndrome or Joint Hypermobility Syndrome), or the type of POTS which is defined by the co-existence of mast cell activation problems. However, I would argue that this tendency to try to place POTS into more manageable ‘subtypes’ is misguided and the equivalent of the blind men being unable to see the elephant before them. Indeed, the ‘breaking up’ of POTS into little pieces is part of the problem, not the solution. As Raj writes: ‘These subtypes may be of value in trying to understand the pathophysiology of POTS, and may help to develop rational therapeutic approaches. However, it is currently quite difficult to characterize an individual patient as belonging to one particular subtype. The putative pathophysiological mechanisms…are not mutually exclusive, and can co-exist in a particular individual.’[27] As these so-called subtypes can indeed co-exist in any given individual, then what if there were a root cause which could explain all of them? Let’s see if the limbic system hypothesis might be able to. In addition, I will also attempt to put forward suggestions as to how the limbic system impairment hypothesis could potentially explain disturbances in the renin-angiotensin-aldosterone network, a key factor in low blood volume in POTS.

  Explaining the POTS Elephant: There are no ‘POTS Subtypes’ Just Limbic System Dysfunction which Affects the Body in Different Ways

  i) ‘Hyperadrenergic POTS’

  There is little which needs to be said about the hyperadrenergic ‘subtype’ as it was the subject of the last chapter. Many POTS patients have high levels of adrenalin in their blood stream for reasons we have already seen, as the level of norepinephrine in the blood depends on the state of the NET protein. The amount of adrenalin in the blood stream varies depending on the extent of this deficiency (and the extent of the crisis in the brain).

  ii) ’Deconditioned POTS’

  I will consider the deconditioning theory in more detail than the other subtypes, as it is one of the more prevalent hypotheses on the origin of POTS. I would argue that, whilst it is true that deconditioning necessarily plays a considerable role in POTS patients, and that research into it is very important (for it shows that cardiovascular reconditioning will necessarily be an important part of making a full recovery), deconditioning itself is not the cause of POTS, but rather an additional consequence of limbic system induced NET deficiency. It is the latter, the inability of blood vessels to constrict upon standing, which leads to the patient having such difficulty with any physical tasks with the result that they become deconditioned. The simple fact is this: if you have POTS for any substantial length of time, you will become deconditioned. In the 2012 Levine study on the effects of cardiovascular exercise on POTS patients, the patients in the study had had the condition at the least for six months before participation and, at the most, for five years. If you are hardly able to do any physical activity for such lengths of time, you will become very unfit. In that sense, it is absolutely correct to say that a period of bed rest can lead to extreme cardiovascular deconditioning, and that any treatment protocol for POTS must take into account the severity of those effects and the importance of treating them through exercise.

  There are, however, several further arguments from common sense against considering deconditioning as the root cause of POTS.

  Firstly, if it were true, then POTS would be an extremely prevalent condition. It would be common for the elderly to develop POTS. This is not the case. Instead, an unlucky (if sizeable) minority have it, among them children, t
eenagers and young adults - many of whom were fit and well before the condition’s onset. How could a ten-year-old child possibly be so deconditioned as to develop POTS whilst an elderly person who has not moved much for several decades does not develop it? The argument that a period of bed rest causes POTS is also surely misguided (even though prolonged bed rest undoubtedly does cause cardiac deconditioning). The overwhelming majority of people who have enforced periods of bed rest do not develop the symptoms of POTS (even though they become weak). Similarly, many who have been disabled for other reasons - such as through paralysis or loss of limb - also do not develop the symptoms of POTS despite being unable to do any activity whatsoever for decades.

  Secondly, if deconditioning really were the cause, then, after say six months intensive cardiovascular training, it should be possible to cease this intensive exercise, and instead engage in basic cardiovascular work. Once the deconditioned person has become ‘reconditioned’, they should be cured. But, in practice, this is not what seems to happen: the patient has to keep up the cardiovascular work at a high intensity for as long as they live. This cannot be right. Rather, their symptoms have been ameliorated, by having increased blood volume through having a stronger heart. As a result, their system is better able to cope with the limbic system dysfunction and resultant NET deficiency, but that, I would suggest, is all. In this way, cardiovascular exercise is the physical equivalent of taking more salt and liquid to boost blood volume. It really helps, but it does not fix the cause. The main point is this: a cure should result in the supine-to-standing differential returning to normal, i.e. a 10-20 beats increase upon standing. It seems that this is not generally what seems to happen to those following the cardiovascular retraining programs: their differential remains higher than that as does their standing heart rate.