Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: Definitions, Similarities, and Differences (2019) Natelson

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: Definitions, Similarities, and Differences

https://www.clinicaltherapeutics.com/article/S0149-2918(19)30003-7/fulltext
(Paywall)

This commentary presents a simplified way of making the diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) using the 1994 Centers for Disease Control and Prevention case definition. The format used can easily be modified for other case definitions. The commentary then discusses whether ME/CFS is the same or a different illness from fibromyalgia. Because overlap exists between the 2 syndromes, some investigators have posited that they are variants of the same illness. I have viewed this as an empirically testable hypothesis and have summoned considerable amounts of data that suggest that the 2 illnesses differ. Were differences to exist, that would suggest different pathophysiologic processes for each, leading to different treatments.

 

Has anyone been lucky to get access to the commentary?

 

I have emailed dr Natelson to see if I could get a copy and he replied the following:
‘This paper has not yet completed the editing process and so is not yet released’

So I guess we will have to wait.

 

Interesting idea that "CFS-only" and "CFS+fibro" could be two different illnesses (the paper uses CFS). They seem to have found a variety of physiological markers that differ between the groups and will be looking for more. Though they don't seem to have a "fibro-only" group. Would have been interesting to see if the "CFS+fibro" just are particularly tired fibro patients or a genuinely different group from both "CFS-only" and "fibro-only".

I have a quibble though with their operationalisation of the ME/CFS diagnostic criteria:

The focus on fatigue instead of on PEM is a problem for patients who experience relatively little fatigue when well-paced but who are instead limited by how little they can do without triggering PEM.

In figure 2, I would have scored worse back when I was mild but not pacing and therefore unrelentingly fatigued and symptomatic. Now that I'm much more severe but pacing strictly most of those symptoms only affect me badly during PEM so on paper I'd look less severe which is nonsense.

 

It is odd that there isn't a straight FM comparison. That would have made more sense.

 

A comment to this article by Frank Twisk has been published: "Letter to the Editor: Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: Definitions, Similarities, and Differences."

 

I believe it was Dr. Byron Hyde who explained the differences between ME pts with pain syndrome and those without? Perhaps it's not FM?

 

There was no correlation between ME and fibromyalgia. In fact I never heard the term until after CFS was invented - I believe it was originally called fibrositis but I may be wrong.

At the time it looked like the Americans (who ignored all we knew about ME and took Fatigue as the critical symptom not PEM) used CFS for fatigue and if you were in a lot of pain you were told you had fibromyalgia as well.

There may be a relationship between the 2 diseases but I am not convinced that doctors take enough care to distinguish the agony of the myalgia part of ME from the pain of fibromyalgia.

 

I don’t think you can affirm that fibromyalgia pain does not feel like agony for the sufferers and how it compares. Until we have an objective measure of pain, if you do not have the condition, you can’t really tell.

I agree however that many physicians do not take care in distinguishing the 2 conditions. Dr Natelson wrote a commentary piece about the fact that the 2 were indeed distinct diseases.

 

I never meant that fibromyalgia is not agonising, only that the pain experienced in ME was minimised when CFS became all about fatigue. The disconnect with ME meant that the adverse effect of exercise was forgotten for years and the pain was not properly acknowledged either. I am sure that many people with CFS/ fibromyalgia actually have ME accounting for their pain. If you have spots because you have measles the doctor must examine you very carefully to know that some of your spots are actually rubella to say for sure you have both diseases at the same time.

It is becoming commonplace nowadays for CFS and fibromyalgia to be treated as symptoms (see the list of symptoms of FND for instance) where chronic fatigue is CFS and widespread pain is fibro instead of 2 distinct diseases.

I am sure this is happening, at least in part, because of the idea of central sensitisation.

This mess of diagnosis and manipulation is very bad for patients. The tests for fibromyalgia have been made less stringent and we all know about CFS/ chronic fatigue confusion. The muddle helps BPSers but is very bad for patients.