Myalgic Encephalomyelitis, Chronic Fatigue Syndrome, and Systemic Exertion Intolerance Disease: Three Distinct Clinical Entities; 2018; Twisk

Myalgic Encephalomyelitis, Chronic Fatigue Syndrome, and Systemic Exertion Intolerance Disease: Three Distinct Clinical Entities

Frank N.M. Twisk

http://www.mdpi.com/2078-1547/9/1/19

 

Until we have some form of testing available, I don't think that anyone can know if they are the same or not. If what this article says is correct, then I'd guess that at least half of us don't belong here on S4ME.

 

Note that if the 2015 Institute of Medicine report recommendations are followed, then "SEID" criteria may change less than 2 years from now.

Not referring the Twisk paper here, but using SEID criteria for any medical study is a really bad idea. It's not just difficult to compare an SEID study to a ICC/CCC/Fukuda etc. study, you can't even compare SEID to SEID if it changes after 5 years.

 

Full text open access at http://www.mdpi.com/2078-1547/9/1/19/htm

 

I think that when the truth is eventually discovered, there will (as many people believe) be various subsets with what we currently know as ME/CFS. As I see it (my personal view), the people who belong in S4ME are those who fit within the overall understanding we have of what ME/CFS means to people today, with today's best understanding of that. And just because good science might in future sub-classify within that, I do not that see any reason at all for some members to suddenly feel like they would not belong - far from it. We are quite literally all in this together.

 

According to the diagram there is hardly any overlap between Ramsey ME and SEID. I would like to see where CCC fits in.

 

The picture ("Venn diagram") he shows is actually what I meant in another thread where I thought about sets and subsets. My claim was that ME is not a subset of CFS but that ME and CFS may have an intersection set. I didn't include SEID though. I wonder if we can really answer the question whether this intersection is empty or non-empty.

I find this paper interesting and important.

 

So, they're not the same, except when they are. The definitions are different but not mutually exclusive.

Post exertional malaise, for example, may fulfill a requirement for the 1994 CFS definition, but it is not mentioned in Ramsay's 1990 ME definition. I have to wonder when the term post-exertional malaise was first used in the literature. I wouldn't be surprised if it originated in the 1994 CFS definition paper. I didn't hear about it until more than a decade later.

If a future definition requires an abnormal 2-day CPET are we going to say that that definition represents a completely different disease from ME and CFS because their older case definitions didn't require that test?

 

I think Twist has got this in a muddle.

Reiter's syndrome and reactive arthritis are defined differently and have some overlap and some not. But a doctor would not say they are distinct clinical entities. They would say there is a spectrum and that the most typical cases fit both definitions. That would be the way I see ME.

The fact that definitions are not the same does not mean that what they are trying to describe are separate entities. It just means that the definitions are different.

 

I don't take that diagram as literally.

 

Actually, it does here

"(2) Neurological disturbance – an unpredictable state of central nervous system exhaustion following mental or physical exertion which may be delayed and require several days for recovery; an unique neuro-endocrine profile which differs from depression in that the hypothalamic/pituitary/adrenal response to stress is deficient; dysfunction of the autonomic and sensory nervous systems; cognitive problems."

 

Ramsay did not talk about PEM but he did talk about an abnormal reaction to exercise. Describing the Royal Free epidemic they said that even examining patients made them sicker.

There were a lot of things implicit about ME, we all seemed to be talking about the same thing in the days before CFS was invented. Getting worse with exercise was felt to be the most important thing about ME with mental exertion causing physical fatigue and vice versa.

It is really hard for people today to understand how CFS turned everything upside down. ME came in epidemics so it was obvious that an infection was involved, even if that infection had been subclinical. Then there was the variability of symptoms so that you could be unable to talk in the morning, have excruciating muscle pain in the afternoon and be blind in the evening (as I have had) - we have now gotten PEM acknowledged again but the variability has still not returned for research.

It became all about fatigue, a minor consideration with ME in the old days where it was treated in the it is with MS. In fact, rather than 6 months of unexplained fatigue the typical ME patient was said to be fairly normal for a few months, then having a collapse for a while, then recovering, more variability. (Of course, 25% were said to recover and 25% to keep getting worse).

I have NEVER fit the criteria for CFS. It may be that no one gets ME anymore or that ME is an energy production disease that is just one of many but making it all about fatigue has really screwed everything up.

Much better description Mij

 

I believe the term PEM only came into existence around the year 2000-2001.

 

Good find! I was going by the 1990 Ramsay paper cited by Twisk. It mentions "a complaint of general or local muscular fatigue following minimal exertion with prolonged recovery time," but doesn't mention other post-exertional symptoms that one might associate with PEM. It also doesn't mention the onset being delayed in some cases. It's interesting that Ramsay's 1986 definition does, however.


The term "postexertional malaise" does appear in the 1994 CFS definition cited in the Twisk paper.

The chronic fatigue syndrome: A comprehensive approach to its definition and study. Ann. Intern. Med. 1994, 121, 953–959.
Fukuda, K.; Straus, S.E.; Hickie, I.; Sharpe, M.; Dobbins, J.G.; Komaroff, A.L.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.325.4042&rep=rep1&type=pdf

 

Yes! I totally agree 100%.

 

That's just it. The case definitions are important because we don't have a biomarker. And PEM is important even if it was not in the first case defintion describing ME. ICC did not exist then but most agree it most correctly defines ME. I have been diagnosed with CFS and I believe I first met SEID (even though SEID did not exist in late 70') and my disease progressed in severity and symptoms through the years and I now believe I meet CCC.

It would not surprise me that there are types and ME may very well be its own disease while CFS and SEID are more alike and it may be a severity issue with them. But I also believe ME and CFS lie on a spectrum.

 

In all definitions of ME I would like so see the word 'fatigue' replaced with 'exhaustion'.

 

Yes I agree. This paper upset me probably more than it should have. I do think it is a useful exercise to compare definitions and see what kind of cohort they lead to, but the conclusions in this paper are misplaced. Until biomedical tests can differentiate subsets patients will be harmed by trying to include or exclude on the basis of arbitrary definitions. Added to that is that patients are stuck with the diagnosis their country prefers to use regardless of the criteria used to diagnose.