Ashok Gupta explains how ME/CFS starts: a virus or toxin triggers post-viral fatigue, while stress sensitizes the amygdala and thalamus to amplify sensory input. Worry about symptoms then conditions the sensitized amygdala to react to normal bodily sensations, creating a cycle that keeps stress-responses and fatigue going.
Around 70%
Now this is a point where a unique bit of brain neurology comes in to help us understand how CFS starts. Basically, you will remember how I spoke about how the amygdala was on high alert. This is when the amygdala is what we call sensitized. This means that because it is on high alert from all the stressful stimuli coming in from all the senses, it can remain on high alert to everything and it is difficult for it to calm down. This is what we call sensitized. In the diagram we can see how the stimuli come in from the left and the stimuli are magnified by the thalamus, which has also become sensitized. That is represented by the magnifying glass. Basically, the thalamus magnifies anything going through it. These messages are then sent to the amygdala. Now imagine the amygdala to be like a volume slider control you might see on a hi Fi or on a tv. And this slider control goes up and down the slider control. Now, studies show that around 70% of people with CFS can remember a particular virus or toxic trigger at the beginning of the illness and they felt that they never recovered from that virus. Now, when the body is trying to deal with a virus or a toxin, the body perceives that it is under threat and it will divert energy away from non essential functions towards fighting the virus or the bacteria, whatever it may be. As an example, we've all had the experience of having flu where our whole body aches and we feel weak and nauseous and we blame it on the flu virus. However, it is not necessarily the flu virus itself that is causing these symptoms. It is actually the triggering of the immune system and the resources being diverted away from other functions in the body. So, let's recap. So far we have two coincidental things going on in the body. Firstly, a particular stressful period in someone's life, mentally, emotionally or physically. And this has reduced the power of the immune system. Secondly, there is a virus or bacteria or other toxin in the body. In 70% of cases of people with CFS because of the stress in a lot of patients, the virus seems to last longer than usual because the immune system is lowered and the person feels run down for quite a while. Once again, there is a minority of patients who don't remember any particular virus. Now, it could be that the body may still have been fighting something off at the time, at the beginning of the illness. Now, because of the lowered immune system, it takes a lot longer than usual for the illness to go. And even once the illness has gone, a person may still feel very run down and tired. Now, this is often known as post viral fatigue, or pvf. PVF is common in the population. Many people who are run down take longer to recover from a virus. They take longer than people who are healthy. So there are now two things contributing to symptoms in the body at the beginning of cfs. One is the symptoms from post viral fatigue or pvt, and the other is from the stimulation of the sympathetic nervous system, the fight or flight response, the stress response with adrenaline and other chemicals tiring the system. So we've got two sources of symptoms there. Now, I don't know if you can remember back, but I'm sure that near the start of your illness, you were probably getting concerned about what was going on. Now, I remember thinking back when I first got ill, I remember saying things like, gosh, why is it taking so long to get better? When will these symptoms go away? I'm fed up a feeling like this. I'm a conscientious person, I've got work to do, I can't be ill. Gradually, I was getting more and more concerned about why I was not getting better. And this was stressing me out even more. Now, according to some groundbreaking research By Professor Joseph LeDoux, when the amygdala becomes sensitised, it becomes very prone to learning new things to become sensitive to. As an example, if you get stressed out about something at work, say, it then becomes very easy to become stressed out about everything else, maybe your partner or something. And because near the beginning of the illness, you were very concerned about what was going on, you may have inadvertently been training the amygdala to become sensitised to the symptoms. The concern you consciously had about still being ill would have sent a message to your amygdala that something was wrong with the body. And because the amygdala is very sensitized, remember, it very quickly starts sending messages up to you as well, saying, hey, the body's exhausted. What's going on here? This is dangerous, right? Or your body is weak, do something about this. This can then cause further conscious negative thoughts, which in turn trigger off the amygdala, creating a negative vicious circle. Now, remember, this may also be occurring completely subconsciously. So if you don't remember these conscious thoughts, it could all be happening under the surface. Now, if we look in this diagram, we can see that the conscious mind and the amygdala are negatively reacting to how the body feels. And this results in stimulation of the stress response or the fight or flight response. Now this adds to the symptoms already being experienced as a result of PVF or post viral fatigue. Now this is often aggravated by the fact that you then may go from doctor to doctor trying to work out what is going on. As well as reading really negative stuff about CFS on the Internet or in books. This can make you feel even more negative. As mentioned earlier, I've certainly noticed that many of my patients generally tend to be very driven people and this may increase the negativity towards the symptoms. It's stopping you from going forward in life. So for example, a person may become more and more agitated at not getting better and therefore the frustration and annoyance trains the amygdala even more that something is wrong with the body. This creates a trauma in the amygdala and this is the beginning of cfs. Now let's also have a brief look at the immune system. Basically, the research shows that some CFS patients have characteristics of someone who has a lowered immune system and some have an elevated immune response. Well, there is evidence that even immune reactions can become conditioned to a particular stimulus. So being subconsciously concerned about symptoms may trigger off certain immune responses. Because this reminds the body of when it was first trying to get over the original virus. For instance, if you give rats some sweet water with a virus, the rat's immune system gets triggered eventually. If you do this enough times, if you simply give the same rats some sweet water, but without the virus, they still trigger their immune responses.
