Research: Diagnostic classification of ME, CFS and Chronic Fatigue

[Ember]

In a comment on the Research1st To PEM or not to PEM post, Frank Twisk writes, It is time to leave the CFS label and 'fatigue' behind us and to make a clear distinction between ME patients (those with PEM and e.g. cognitive impairment) and 'CFS' patients (those without PEM).

Here's his full comment:

Frank Twisk 28. Apr, 2012 at 6:08 am #

Oxidative stress is just one of the many abormalities induced/intensified by (mental and physical) exertion that could account for PEM. As substantiated in Twisk and Maes (2009):

Exertion induces post-exertional malaise with a decreased physical performance/aerobic capacity, increased muscoskeletal pain, neurocognitive impairment, fatigue, and weakness, and a long lasting recovery time.

This can be explained by findings that exertion may amplify pre-existing pathophysiological abnormalities underpinning ME/CFS, such as inflammation, immune dysfunction, oxidative and nitrosative stress, channelopathy, defective stress response mechanisms and a hypoactive hypothalamic-pituitary-adrenal (HPA) axis.

Using Fukuda et al. (1994) criteria and PEM, fatigue, and a subjective feeling of infection as discriminatory symptoms we recently established that ME, CFS (Fukuda/not-ME) and CF are distinct diagnostic categories.

ME patients have significantly higher scores on concentration difficulties and a subjective experience of infection, and higher levels of IL-1, TNF?, and neopterin than patients with CFS.

Myalgic Encephalomyelitis (ME), Chronic Fatigue Syndrome (CFS), and Chronic Fatigue (CF) are distinguished accurately: Results of supervised learning techniques applied on clinical and inflammatory data.
Psychiatry Res. 2012 Apr 20. doi: 10.1016/j.psychres.2012.03.031.
Maes M, Twisk FNM, Johnson C.
http://www.sciencedirect.com/science/article/pii/S0165178112001400

It is time to leave the CFS label and fatigue behind us and to make a clear distinction between ME patients (those with PEM and e.g. cognitive impairment) and CFS patients (those without PEM).

http://www.research1st.com/2012/04/27/pem-case-def/

It seems that the intent here is to modify Fukuda rather than to support using either the CCC or the ME-ICC.

 

[Guido den Broeder]

Twisk used to be a fan of Pall's model. Problem is, that's just part of the pathology.

 

[Guido den Broeder]

They have to be 3 distinct conditions.

I can't agree with that. Neither of the three is a 'condition'.

ME is a disease. CFS is a selection method for clinical trials. CF is a symptom.

 

[Firestormm]

Thanks for spotting the comment Ember

 

[free at last]

I can't agree with that. Neither of the three is a 'condition'.

ME is a disease. CFS is a selection method for clinical trials. CF is a symptom.

Ok maybe poor choice of wording, but something that can change from one state to another from a disease. I used the word condition loosley. CFS maybe more than just a selection method for clinical trials, Bio Markers seemed to make it distinct from CF, if i read the header of the paper right. The differences in symptoms between ME/ and CFS and CF make it a bit more than just a selection method. It appears to have a different set of symptoms or likely severity of symptoms.

it might well be a selection criteria As ME is, ( being a disease doesnt change that ) but just as ME is a disease. CFS is also a set of symptoms rather distinct from ME. and according to this paper from CF. Next we are going to hear its not possible to have ME and move to another state. Many would class as CFS.

Theres is no evidence for that, Suggestions Either way infact. Though agreed it appears rarer to improve from ME. Which may or may not indicate mis diagnosis from those that have moved to a different state of illness. At the moment the jury is still out on that. which just goes to show how badly having to use definitions to diagnose a illness actually is. one can have all the classic symptoms of ME then move to a state that more resembles CFS. Then what. are other illnesses mimicking the criteria of ME. If so then the criteria for ME are useless.

 

[Firestormm]

I think I agree Free. Who's to say 'ME' is not a worse state of 'CFS'? Mind you, who's to say PEM is unique to 'ME' either? Way to go before they nail that one down. There are still separate schools of thought on what actually PEM is and what might cause 'it' never mind it's uniqueness...

 

[free at last]

Yes Firestorm and its the biggest diagnostic of the condition ME. Rather worrying that on so many levels. I think some patients may find it hard to acknowledge what we are suggesting here. Because of the fact there is no conclusive medical test yet for ME. Suggesting there is problems with the one critera that we would all love to belive is fail proof. But clearly is not. is just another uncertainty that many patients will find it hard to accept. And i can see why. and have much sympathy for those that would prefer at least some strong indication that there illness is being correctly diagnosed. unfortunately i have less faith. Some of those reasons are being discussed. And to my mind are valid. And extremly worrying. Not everybody can afford private testing to rule out all the possible conditions that can appear to be ME/CFS with PEM but infact may be something intirely different. Its highly likely there actually isnt one type of ME/CFS and what i mean by that is. multiple causes producing a similar condition
of ME/CFS symptoms with PEM. But with possibly a number of symptoms that differ from another patient diagnosed with ME/CFS possibly because the cause was different. Like my itchy throat for example. thats a unusual one. yet other symptoms i share with others, senstivety to light noise. fatigue sweating. nausea. on and on. This whole picture is not as clear cut as many would rather it be. And will make comments like i was correctly diagnosed and so forth. As the fear of what i am suggesting is as of 2012 Even ME with all of its critera satisfied. Doesnt really explain some of the differences we are seeing between patients symptoms. duraton of illness. severity. potentiall for recovery.Or non recovery. the shifting of symtoms from one state to another. Its all pretty confusing. whats needed is a diagnostic test that says yes you do or do not have ME, Or even ME type1 ME type2 ME3 ect. I just dont belive we know the half of it yet.

 

[Guido den Broeder]

ME has an incubation time of 4-7 days. There is no transfer from CFS to ME, or vice versa for that matter. The two are different types of entities.

If you've had ME for 6 months you are likely to satisfy most sets of CFS criteria, expect for that much overlooked requirement that your symptoms aren't supposed to have a known medical explanation.

 

[free at last]

ME has an incubation time of 4-7 days. There is no transfer from CFS to ME, or vice versa for that matter. The two are different types of entities.

If you've had ME for 6 months you are likely to satisfy most sets of CFS criteria, expect for that much overlooked requirement that your symptoms aren't supposed to have a known medical explanation.

Interesting i didnt know ME has a incubation time. I thought incubation times are viruses and bacteria. so are you saying there is a particular virus that has a incubation time that youve discovered or know about.

Different viruses tend to have different incubation times. So i assume your talking about one particular virus or type of bacteria with a known incubation time.

So what evidence do you have that ME and CFS can not interconnect at different stages of illness. Or from your incubation time comments. different stages of bacterial or viral infection ? lots of certaintys in your comments. but many unkowns. Could you fill us in with the unknown evidence that leads you to these conclusions. I certainly could be wrong. And would love to see your evidence which proves that. Cheers

 

[rlc]

Hi free at last, the 4-7 day incubation period for ME is known, because previous ME epidemics before the invention of CFS were very well studied and a lot of the major ones happened in hospitals, where they were able to track the length of time from a none infected person coming in contact with an infected one and then getting sick, this was about 4-7 days and this finding was recorded in many epidemics.

It is a very overlooked, but extremely important finding, because it means that viruses that have a longer incubation period like EBV, which has an incubation period of 40 days cannot possibly be the cause of ME, it is because of his knowledge of what MEs incubation period is, that Dr Hyde was immediately able to say that XMRV could not possibly be the cause of ME, because all Retroviruses have long incubation periods, see page 7 http://www.nightingale.ca/documents/GoteborgConference.pdf

Unfortunately almost all researchers into infectious causes of ME have ignored the old research into ME and have wasted fortunes investigating lots of different viruses like EBV, HHV6 CMV etc as possible causes of ME, when all of these viruses have long incubation periods which means it is scientifically impossible for them to be the cause of ME.

All the best

 

[free at last]

Hi free at last, the 4-7 day incubation period for ME is known, because previous ME epidemics before the invention of CFS were very well studied and a lot of the major ones happened in hospitals, where they were able to track the length of time from a none infected person coming in contact with an infected one and then getting sick, this was about 4-7 days and this finding was recorded in many epidemics.

It is a very overlooked, but extremely important finding, because it means that viruses that have a longer incubation period like EBV, which has an incubation period of 40 days cannot possibly be the cause of ME, it is because of his knowledge of what MEs incubation period is, that Dr Hyde was immediately able to say that XMRV could not possibly be the cause of ME, because all Retroviruses have long incubation periods, see page 7 http://www.nightingale.ca/documents/GoteborgConference.pdf

Unfortunately almost all researchers into infectious causes of ME have ignored the old research into ME and have wasted fortunes investigating lots of different viruses like EBV, HHV6 CMV etc as possible causes of ME, when all of these viruses have long incubation periods which means it is scientifically impossible for them to be the cause of ME.

All the best

Hi Thanks for the information When i read about Ramseys understanding of the illness. I have to say the guy seemed to be pretty spot on, in so many ways. When i read about him describing the illlness. it was like he personally had been with me through all the really bad times early on in the illness. That kind of information can not really be guessed. And i was actually quite surprised, how much he really knew about the illness. that echoed my personal experiance of it.

So i wouldnt for one second dispute what the older information has been telling us for all this time.

But certain questions still do arise. One obviouse one ( btw i always belived it was a virus ) is surely if theres a incubation period testing could have picked up this virus. But none with a incubation period mentioned has been proven to cause the illness ?

Infact Lyyn gilderdale seemed to get ill after a vaccine ?

I never gave this illness to my family ?

Even though i had repeated infections with very high temperatures. Not once did my partner fall ill while i was getting these flu type attacks with fever ?

And i am sure as much as there is evidence of outbreaks ( incline village ) there is also evidence of ME not being something that people catch ? I think one has to be very careful to assume too much. from isolated outbreaks compared to other evidence.

It could well be that infection sets off a cascade of immune dysfuntions ( with or without retroviruses being involved. ) auto immune dysfuntions. It actually could be different infections that produce ME especially if there was a underlying retrovirus. Or a immune dysfuntion ( auto immunity )
So i dont belive the evidence has proven this incubation period at all as being the cause of all ME cases.

Im not saying there wasnt cases of ME involved with a time span of 4 to 7 days infection. Im saying that doesnt fit the intire population of ME sufferes. Or a potential spread of ME.

Most infections that are highly contagiouse.are so obviouse that ME would be seen like the common cold or influenza with it spreading like wildfire. That may have happened at the royal free hospital incline village and other places. But it clearly does not and has not always behaved like that. If it did. im sure the mystery would be solved by now. And the offending virus discovered much more easily than has been the case. Maybe im wrong but thats my thoughts on this outbreak evidence
If anyone knows of reasons as to why im wrong about this plz give them. because i might be missing something maybe ? I will say this whatever the virus is. it does become part of the human gene. like retro viruses. or viruses like chicken pox ect In other words ive still got it. But like the chicken pox virus it remains dorment after very long periods of causing immune dysfuntion

After reading your link. I noticed this conclusion that i dont understand

qoute from your link

It is simply not credible that any single causative agent that can cause these
patients diverse illnesses or that any single treatment can be widely employed to give a
successful resolution to the vast majority of M.E. and CFS patients

If i am reading this right, no single virus can be the cause of all ME patients. If thats the case the incubation period being limited to the time span mentioned, wouldnt arise. There would be different incubation periods ?

 

[Dolphin]

Just to point out that there are different levels of PEM:

In analogy with the FF scale we have also scored the severity of post-exertional malaise as follows:
0:no post-exertional malaise;1:mild exacerbations of fatigue/pain/neurocognitive symptoms following exercise (either cognitive or physical); 2: moderate exacerbations of symptoms following exercise; 3: severe, incapacitating exacerbations lasting less than 24 h; 4: incapacitating exacerbations lasting >24 h but less than 2 days; 5: incapacitating exacerbations lasting >2 days; 6: a clinical relapse.

The groups were divided up as follows:

107 subjects fulfilled the ME/CFS criteria according to Fukuda, while 37 patients did not fulfill Fukuda’s criteria and,
therefore, were classified as CF. Consequently, we have divided the ME/CFS patients into those without (n=58; labeled as CFS) post-exertional malaise lasting for more than 24 h and those with (n=49; labeled as ME) post-exertional malaise.

So the CFS groups had scores of less than or equal to 3 on the PEM scale, while the M.E. group had scores of 4 or greater.

So that distinction is far from clear cut, especially when it's not defined what the exertion is - people could be talking about different levels of exertion.

 

[Simon]

Just to point out that there are different levels of PEM:

So the CFS groups had scores of less than or equal to 3 on the PEM scale, while the M.E. group had scores of 4 or greater.

So that distinction is far from clear cut, especially when it's not defined what the exertion is - people could be talking about different levels of exertion.

That's a very important point. It's a major problem when trying to classify PEM, and Lenny Jason has similarly not graded PEM by degree of exertion. This matters because, for example, if minor exertion, of the kind the is likely to occur every day, leads inevitably to PEM >24 hours then such a patient is locked into a cycle of perpetual PEM - but there are many for whom this is not true.

A more descriminating approach would help linking the level of PEM to the level of exertion. After all, most of us pace precisely to avoid PEM, meaning we we can often avoid PEM so long as we pace - but that general absence of PEM says more about pacing than the underlying illness.

 

[user9876]

I know that people like to differenciate between ME and CFS but I see this as a feature of the groups that created the CFS label.

From a reseach perspective I think it makes more sense to represent each individual as a vector of symptoms and then look at which seem to respond to different treatments or have particular bio markers. It may be that certain bio markers associate with certain symptoms.

The problem comes when a group of people with a wide range of symptoms are lumped together and treated as a homogenous whole rather than trying to understand what is similar and what is different.

Until we understand mechanisms is seems fairly arbitary to label one set of symptoms with one name and a slightly different set with a different name. For example PEM may be a likely symptom but not one that necessarily follows from what ever biological mechanism is found.

 

[Firestormm]

Thanks Dolphin - that was from the full paper I presume? I don't think I did ever get round to reading the whole thing.

I was pondering PEM today actually, so this is opportune. I think that if they continue to explore the physical aspects that might cause/lead/explain PEM in ME, they will need to look beyond 'ME/CFS'/Whatever i.e. outside of our condition for comparison.

At a very basic level, my Mum has Osteoarthritis and if she pushed herself, then she will suffer from what could be described as PEM with (obviously) a massive increase in pain and debilitation.

That there is a scale for PEM (I don't know if this is in common use or was developed for this paper specifically) would suggest that when further research into possible explanations have resulted in 'something', we can perhaps move towards proving if PEM is indeed unique to ME.

It is unlikely - I would suggest - that it is a unique condition and not because of my Ma's experiences! I would posit that PEM is a state that can occur with other illness states - I mean does it not appear to be the same reaction as one experiences when trying to 'push it' when fighting e.g. the flu or an acute viral infection?

It always has done to me. I don't/can't see PEM as being a definitive 'marker' and I am very cautious over moves to develop some sort of 'test' specifically for PEM as a 'marker' for this condition as a whole.

Not because I don't think that I suffer from the description that accompanies PEM, because I think I do, but rather because I think 'PEM' is part and parcel of 'ME' rather than a specific symptom of it (and for that matter so is 'cognitive dysfunction') and that 'both' fluctuate along with the condition in general.

Anyhoo... I'll dig out that paper and have a better read than I obviously did before. I do recall sending it to Cort though - notice he hasn't commented on his 'own paper'

 

[Firestormm]

We crossed posts there User. Not sure if we're kind of saying the same thing or not?

I think that for research purposes and in trying to understand the mechanisms behind 'What is happening biologically to these patients when/before they exert themselves?' looking at 'PEM' in relation to 'exercise' is probably important - as is the (larger) question of 'Why do these people react/find it so hard to maintain/engage/recover from exercise?'

But for the purposes of diagnosis, specifying that you MUST have 'PEM' before I can diagnose you with ME (even/especially if it includes a couple of other things that are mandatory) - when PEM can and probably is fluctuating seems too 'cut and dried' for me and could leave even more patients undiagnosed/untreated (should any specific treatment ever occur).

Similarly, saying people who 'don't have' PEM don't have 'ME' (as happens on forums etc. and elsewhere) appears unduly 'hopeful/harsh/derogatory'. A little like saying people with 'CFS' don't have 'ME' or suffer depression and are therefore misdiagnosed/don't belong.

I think there is a clear need to distinguish between fields of/and direction in which research is proceeding and what happens when a person is diagnosed i.e. in a clinic/the 'real world'. We tend I think to not place a lot of faith in the ability of the diagnosing physician/specialist to determine an appropriate diagnosis based on (in large part perhaps - and not necessarily a bad thing in the absence of any 'test') a thorough understanding of a patient's history.

This aspect of any 'criteria' appears overlooked/downplayed. And yet it plays an enormous and important part in any diagnosis. Of course in an ideal world of 'modern medicine' we'd all be scanned with something out of star trek and prompt treatment would occur

Sorry. Run out of steam. To be continued perhaps? Better read the paper. Seem to have 'gone off on one'.

 

[alex3619]

With respect to incubation periods and epidemics, one important question has never been definitively answered. There is most probably incubation of a pathogen, but it might not be the same pathogen in all cases. Most importantly, is/are the pathogen/s causal or a triggering event? If it triggers already pre-existing pathophysiology to drive it from subclinical to clinical pathophysiology, then the time period for development of ME could be much longer than 7 days.

The reason that people are going with a short incubation period is that it appears to be the simplest explanation. It certainly needs to be taken into account, but its not necessarily the incubation period for ME itself - it could just be the final phase of ME development, the thing that shifts it from potential ME to actual ME.

Bye, Alex

 

[Ember]

Similarly, saying people who 'don't have' PEM don't have 'ME' (as happens on forums etc. and elsewhere) appears unduly 'hopeful/harsh/derogatory'.

But that's exactly what the ICC and CCC panels of experts say. According to the Fukuda definition, CFS patients may have PEM. But according to the ICC and CCC, the ME subset of patients must have PENE (or PEM). In other words, CFS patients may be exercise intolerant, but ME patients are exercise intolerant by definition.

I find the definition of PENE helpful:

Postexertional neuroimmune exhaustion (PENE pen’-e): Compulsory

This cardinal feature is a pathological inability to produce sufficient energy on demand with prominent symptoms primarily in the neuroimmune regions. Characteristics are as follows:

1. Marked, rapid physical and/or cognitive fatigability in response to exertion, which may be minimal such as activities of daily living or simple mental tasks, can be debilitating and cause a relapse.

2. Postexertional symptom exacerbation: e.g. acute flu-like symptoms, pain and worsening of other symptoms.

3. Postexertional exhaustion may occur immediately after activity or be delayed by hours or days.

4. Recovery period is prolonged, usually taking 24 h or longer. A relapse can last days, weeks or longer.

5.  Low threshold of physical and mental fatigability (lack of stamina) results in a substantial reduction in pre-illness activity level.

 

[Firestormm]

Thanks Ember. Yes I am aware of that - though am happier to see 'exertion' rather than 'exercise' being used/talked about of course. But my personal opinion is that this is not a 'symptom' but rather is the condition itself i.e. I don't believe you can separate 'PENE'/'PEM' from 'whatever you want to call the condition'.

Invariably, I sincerely doubt that if you ask patients at the point of diagnosis (simplistically) 'Do you experience difficulties with cognition and sustaining/initiating/recovering from mental and physical exertion to the extent that it is a persistent worry and debilitation?' the answer will ever be 'No'. Indeed a diagnosing physician will hopefully have established this and reached this conclusion before diagnosing the condition i.e. probably wouldn't need to ask such a direct question.

That's assuming it is a direct question and one even worth asking of course, as it could apply to other conditions equally; and these criteria don't take account of people being reassessed and having a relative 'remission' who do not report this particular 'symptom' as being of concern at that time. What happens then? It is after all still regarded as a 'fluctuating condition'.

Also, before different people start publishing these types of criteria, there should be research carried out that attempts to prove the criteria apply to patients with 'our condition' and 'our condition' alone. I would like to see e.g. 'PENE' applied to a mixed (blinded) cohort of patients - including those with 'our condition' - at this stage i.e. without any specific biological 'test', to see if those with 'our condition' can be identified.

I guess I am concerned that we head increasingly for a situation where various sub-categories are created in advance of any objective testing that definitely identifies cohorts of patients and without any specific treatment to offer said patients. I was reading Cort's comparison of that Primer that was published the other day and we have another one expected from the authors of the ICC - who's right? What are the objectives? What was wrong with the CCC? Things like that just bother me I suppose.

Anyway, I have the above paper now so I'll give it a spin

 

[Firestormm]

In a comment on the Research1st To PEM or not to PEM post, Frank Twisk writes, It is time to leave the CFS label and 'fatigue' behind us and to make a clear distinction between ME patients (those with PEM and e.g. cognitive impairment) and 'CFS' patients (those without PEM).

Here's his full comment:



It seems that the intent here is to modify Fukuda rather than to support using either the CCC or the ME-ICC.

Just reading back through the thread afore reading the full paper. If ME = those with PEM etc. why the name ME? Why not something that better reflects the nature of the disease? I guess their contention is that the 'inflammatory' markers they have used are adequate for the nomen. However, (and I need to check in the paper) there were patients subsequently classified as having 'CFS' who had recorded scores in this respect. So, like the hidden measure of exertion - there is an applied 'cut off' point, but we don't know what this is based on or it's nature. And I don't know if the 'inflammation' measure is a realistic one to use. Anyone?