Why did this happen to me?
Written by Professor Mark Edwards
This is a big and complicated question. I think to start with it is important to address the issue of psychological factors again. Many of you will be aware of the term “conversion disorder”, which is one of the many words used to describe FND. It is based on a specific theory that functional symptoms are caused by a reaction to an underlying psychological stress/trauma which is somehow converted into physical symptoms. This theory is very widely known amongst doctors and is the commonest way the diagnosis is explained to patients.
The problem is that when this theory is put to the test, it turns out to be relevant (possibly) for only a proportion of people with FND. Thus, many people with FND have no history of major emotional traumatic events, or major depression/anxiety, or at least not more than other people in the general population. There is also the problem that as soon as one starts to describe a symptom as being due to a psychological problem, it can seem as though the symptom is then “not real” or could be made better just by pulling oneself together. This issue is a problem in general with the way that people with psychological problems are generally devalued by societal attitudes, whereas in fact psychological problems are just as much “brain” problems as neurological disease. However, there is often no escape from the stigma of being diagnosed with something that is “just” psychological.
My own research and that of others does support the idea that a very important trigger to the onset of symptoms in many people with FND is a physical triggering event, and it is interesting that this also came up in some of the questions you raised. This event might be an injury, an operation, a “normal” illness like the flu, or a more serious medical illness. The point is that all these physical triggers give the brain new information about how the body is working (or not working), and this experience seems to be able, in vulnerable people, to trigger off FND. It is very important to realise that the FND is not directly related to the physical trigger (e.g. if the physical trigger is a bang on the head, the FND is not caused by brain damage caused by the injury). By using the phrase “vulnerable people” above, what I mean is that these physical events (injuries, illness etc) happen to millions of people every day, but only a few go on to develop FND. So there must be factors that make some people vulnerable. This is where I think that psychological factors can be relevant in some people. For example I see many people where the physical trigger has set off “fight or flight” reactions in the body (hyperventilation, raised heart rate, a feeling of disconnection from the world around), but though these feelings would usually be associated with an emotional feeling of panic, people have not experienced this. This reaction may help increase the effect that the physical trigger has. Many people I see have been working extremely hard, sometimes over years, before the onset of their symptoms, and it is possible that physical and mental exhaustion might make one more vulnerable. There is likely to be a combination of many factors that add together to trigger FND, and these might be very different between different people. This is why I think it is important to take a broad view of potential triggering and maintaining factors, and to consider all possibilities in an open and honest way. This includes thinking about psychological and lifestyle issues, and if these appear to be important, these should be included in thinking about how to treat the problem.
For this reason, people with FND are in a difficult position in a world where we still classify things in terms of physical and mental illnesses, even though this makes very little sense when one is talking about the brain. Under changes that are underway at the moment in International Disease Classification systems (which are boring but important), functional neurological symptoms are likely to be able to be classified as both a “physical” and a “mental” illness.