Fibromyalgia is the classic condition of chronic widespread pain.
Its meaning is the pain, as we’ll talk about in a little bit more detail later, needs to be represented in all 4 quadrants of the body. So, if somebody has purely localized pain, that is not fibromyalgia.
Fibromyalgia is a condition where the pain is typically diffuse and widespread.
We know that, in general, people with fibromyalgia have heightened sensitivity to pain, which is called hyperalgesia but, the changes that occur in their CNS will also produce unusual symptoms such that things that don’t usually cause pain, like light touch, are misperceived as being painful and that’s a process caused allodynia.
Pain very seldom exists by itself, and that’s partly because the pathways in the brain that transduce pain are also very much involved with key biologic processes like sleep, cognition, memory, and mood. So, it’s not surprising that the fibromyalgia patients also are characterized by disturbances in sleep, disturbances in thinking and feeling, and very often have associated problems with depression and anxiety.
Not only do they have pain, but they also have related symptoms such as stiffness, which can also be really as bad and the pain. We’ve talked a little bit about comorbid conditions and there are a number of psychiatric comorbid conditions, such as anxiety and depression.
There’s a lot of other what we might call bodily symptom conditions, things like irritable bowel syndrome, chronic fatigue syndrome, and migraine headaches that are also highly comorbid and are very often seen in patients with fibromyalgia.
There’s a process that occurs not only in the periphery but really especially in the spinal cord and brain called central sensitization, which is a complex process but, at the end of the day, what it means is that under conditions that give rise to fibromyalgia, it appears that the CNS becomes overly responsive, not only to pain signals, but sometimes signals that are not even directly pain related but get translated into the brain as representing pain.
It really looks like this process of the CNS becoming overly sensitized is directly relevant to how fibromyalgia develops and probably how it’s maintained.
In psychiatry, there is a term kindling that is often applied to individuals who suffer from mood disorders and even possibly some of the anxiety disorders.
Now, would we think that there is some kind of relationship between kindling and central sensitization that we see in fibromyalgia? And, if so, what would be the clinical relevance of that?
The kindling phenomena are really literally what you just talked about, a sensitization of the CNS.
Fibromyalgia is literally kindling of, again, the CNS through the spinal column. The mind-body colliding again, and the clinical implications are quite evident.
Run into a scenario of pathologic pain, do your very best to stop it early, because the progression of the illness may be much more complicated than what we have at our hands right now and, much more difficult to treat.
People with mood disorders often early in the disease need something psychologically painful, a social stressor, to have a depression, but that with each succeeding episode, the disease becomes less and less dependent on those external pains emotional pains.
It’s an exact analogy in central sensitization where fibromyalgia processes will often start with a physical pain an accident or something that sets up tissue damage and, especially when repeated, that can lead to the same sensitization you see in mood disorders.
We know and will talk about the fact that the brain changes you see in chronic pain states such as fibromyalgia overlap very much with conditions of depression, which you can really reformulate as sort of like pain syndromes in response very often to psychological pain, whereas fibromyalgia often arises, although not exclusively, but can arise in response to physical pains.
Fibromyalgia, like all complex modern illnesses, is a quintessential example of genetic vulnerability meeting environmental adversity.
Fibromyalgia is not just caused by genes and is not just caused by things, either physical or emotional, that happen to people.
It really looks like certain genes make people vulnerable to developing fibromyalgia in response to adversity.
Mind stress can be a big risk factor for developing fibromyalgia, but so can things like medical illness or damage to tissue like in a motor vehicle accident.
These are all examples of adversity, and people that have genes that are more likely to respond by setting in motion these sensitization patterns are probably at risk for developing fibromyalgia.
Genes that make people more sensitive to their environment are risk factor genes for all these complex illnesses.