A few days ago, Gary suggested that I write about the parasympathetic nervous system and Parkinson’s. I have wondered how, especially since so much excellent material has been written on the subject before. Therefore, I’ve decided that the most useful thing I can write is a simple overview that gives the context for people affected by PD, which they can use as a sprinboard to research more detailed information, if needed.
My background is law – patent law – not science, but with engineer Steve Walpole I have spent a great deal of time studying the brain and developing new technology which can measure and influence the brain, and as part of this, I have been observing people with Parkinson’s.
There are three divisions to our autonomic nervous system, which controls bodily functions that are largely unconsciously directed, such as our heart rate, respiratory function, urination, breathing, and digestive system:
- our enteric nervous system, consisting of the neurons which govern the functions of our gut/intestinal tract;
- our sympathetic nervous system, made up of neurons which activate our fight/flight response (and freezing, about which more below);
- our parasympathetic nervous system, governed by our vagus nerve and long nerves joined onto the vagus nerve, which penetrates into the brain and many areas of the body, responsible for the body’s “rest and digest” functions.
Parkinson’s may start in the gut. Constipation is one of the risk factors for the development of Parkinson’s, and the gut bacteria of people with PD has been found to differ from that in a normal, healthy human gut. And since our gut bacteria affect our enteric nervous system that most likely indicates the gut damage causes malfuncions of the nervous system. Indeed, I have seen the mental and physical health of Parkinson’s patients plummet with antibiotics – an indication of the importance of gut bacteria to the wellbeing of a person with Parkinson’s. A weakened enteric nervous system means, in turn, weaker messages conveyed from the gut to the brain via the vagus nerve - the conduit for messages from the enteric nervous system, and hence the means by which intelligence from the gut is conveyed into and from the brain - and will affect vagal tone and strength, so that the balance between the sympathetic and parasympathetic nervous systems is thrown out. And as stress increases, so the digestive system shuts down, affecting gut bacteria further.
The sympathetic and parasympathetic nervous system are in opposition to each other. Only one can be activated at a time. With a healthy lifestyle and body, that would normally be the parasympathetic nervous system, since the sympathetic nervous system is activated in times of stress, and has the effect of shutting down most of the body’s systems other than those required in order to fight or flee for our survival. I have set out below some of the things which occur in the body when each of these systems is activated:
Historically, times when we needed to activate our sympathetic nervous system would have been infrequent, and once the crisis was over, we would have been able to recover. Now, we are confronted by stressful situations constantly, and our body doesn’t have time to recover– and as it becomes ever more stressed, so our body is damaged, and the effects of stress build up. In the person with Parkinson’s, the balance between the sympathetic and parasympathetic nervous system is thrown out, vagal tone weakened, the sympathetic nervous system increasingly activated and it can be hard to activate the parasympathetic nervous system.
What happens to the person with Parkinson’s as a result of over activation of the sympathetic nervous system / under activation of the parasympathetic nervous system?
- Freezing - this happens as a response to fear, and in healthy people with a strong nervous system freezing is often momentarily before we fight or flee - we freeze, breathe, breathing activates the vagus nerve, and then we fight or flee - but a person with Parkinson’s and/or a poor vagal tone can get stuck in freeze mode;
- Little time for the body to rest and recover;
- Poor digestion;
- Greater risk of diabetes;
- Muscle tension/pain;
- Immune system weakens;
- Incontinence - the body holds on to urine during the day, when sympathetic nervous system is activated, and lets go at night, when parasympathetic nervous system is at last activated;
- Poor quality sleep – high levels of cortisol and adrenaline impact on melatonin production and impair sleep quality, as do tense muscles;
- Tremor / muscle tension;
- Shallow fast breathing;
What can the person with Parkinson’s do?
- Nurture their gut bacteria, so that the enteric nervous system is in turn nurtured and strengthened;
- Improve vagal tone though exercises which stimulate the vagus nerve and by deliberately relaxing - meditation, mindfulness, and so forth;
- Practise the activities associated with the parasympathetic nervous system – slowing breathing will be good for us and relax us – and relaxation will slow our breathing - both work;
People close to me have Parkinson’s. I have encouraged them to use the Zeez Sleep Pebble, of which I am co-inventor, to help their sleep. The Zeez emits frequencies associated with relaxation and sleep and is designed to prompt poor sleepers to follow the same pattern. It starts with alpha and theta frequencies and can be very effective. It is being trialled at Plymouth University hospital (case series) with people with Parkinson’s related sleep disorders. But it isn’t convenient for daytime use – designed to go under the pillow. I have used it nevertheless, by putting into the hat or collar of a panicking, frozen friend with PD, and seen him calm down in a few minutes and unfreeze, and many people use it during the daytime for a few minutes to relax. Recently, a piece of new tech enabled us to build a small wrist worn alpha device, which we can make using readymade cases without huge start-up costs. I am thrilled, because I think this could really support the body in activating the parasympathetic nervous system and that supporting the body in this way can give us a visceral sense of what to do so that we become more proficient at relaxing, eventually even without the support of an aid. You can find more information about this exciting trial on my website at http://www.zeez.org.uk/product/zeez-alpha-device/ and we hope people with Parkinson's in particular will be willing to try it, help us develop it and feedback their experiences.
For further information about the overlaps between stress and PD and what can be done to alleviate symptoms based on this, please see: