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ME/CFS: Diagnostic Criteria

Pyrrhus

Senior Member
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Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Diagnostic Criteria

To determine which of your symptoms may be consistent with ME/CFS, you can consult the following diagnostic criteria:

International Consensus Criteria (ICC) - A comprehensive set of diagnostic criteria, based upon the older Canadian Consensus Criteria. It uses the term "Myalgic Encephalomyelitis" and discourages the use of the term "Chronic Fatigue Syndrome". It also uses the term "Post-Exertional Neuroimmune Exhaustion (PENE)" instead of the older term "Post-Exertional Malaise (PEM)".

Canadian Consensus Criteria (CCC) - An older, but still comprehensive, set of diagnostic criteria for ME/CFS, agreed upon by top ME/CFS specialists.

IOM/NAM Diagnostic Criteria (SEID) - A basic set of diagnostic criteria that is much less detailed than the ICC or CCC, but is easier to understand. It encourages use of the term "Systemic Exertion Intolerance Disease" or SEID, instead of ME/CFS.
 

Pyrrhus

Senior Member
Messages
4,172
Location
U.S., Earth
International Consensus Criteria (ICC)

International Consensus Criteria (ICC) - A comprehensive set of diagnostic criteria, based upon the older Canadian Consensus Criteria. It uses the term "Myalgic Encephalomyelitis" and discourages the use of the term "Chronic Fatigue Syndrome". It also uses the term "Post-Exertional Neuroimmune Exhaustion (PENE)" instead of the older term "Post-Exertional Malaise (PEM)".

To qualify as having Myalgic Encephalomyelitis according to the ICC, you must have the following:


Post-exertional neuroimmune exhaustion (PENE) (also known as PESE or PEM):
  • A "post-exertional symptom exacerbation" (PESE) defined by "marked, rapid physical and⁄or cognitive fatigability in response to exertion". PENE may occur immediately following exertion or be delayed for hours or days. Recovery from PENE may take days, weeks, or longer. This lack of stamina results in a substantial reduction in daily activity. (also known as PESE or PEM)

At least 3 of the following 4 neurological symptoms:
  1. Cognitive dysfunction (formerly known as "brain fog")
  2. Pain, either headaches or increased pain sensitivity
  3. Sleep problems, either disturbed sleep patterns or unrefreshing sleep
  4. Sensory or movement dysfunction, either light/sound hypersensitivity (including blurred vision) or muscle weakness (including muscle twitching or balance problems)

At least 3 of the following 5 immune or gastrointestinal symptoms:
  1. Flu-like symptoms that occur or worsen after exertion, including sore throat, sinusitis, or lymph node swelling
  2. Frequent infections, with prolonged recovery
  3. Irritable Bowel Syndrome (IBS), including nausea, pain, bloating, constipation, or diarrhea
  4. Frequent urination
  5. Food sensitivities or Multiple Chemical Sensitivity (MCS)

At least 1 of the following 4 "energy" symptoms:
  1. Orthostatic Intolerance (OI), palpitations, or arrythmias
  2. Breathing problems ("air hunger" or "dyspnea")
  3. Body temperature problems, including night sweats, feverish feeling, cold hands or feet
  4. Hypersensitivity to a hot or cold environment


For more information, see:

Primer for Medical Practitioners
by the authors of the International Consensus Criteria
http://www.investinme.org/Documents/Guidelines/Myalgic Encephalomyelitis International Consensus Primer -2012-11-26.pdf

Do I Fit the International Consensus Criteria?
by MEAdvocacy
https://d3n8a8pro7vhmx.cloudfront.n...636/ICC_Questionnaire_Nov_2016.pdf?1478717636

Do I Have M.E.?
by the Swiss ME/CFS Society
https://sgme.ch/icc/en/
 

Pyrrhus

Senior Member
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4,172
Location
U.S., Earth
Canadian Consensus Criteria (CCC)

Canadian Consensus Criteria (CCC) - An older, but still comprehensive, set of diagnostic criteria for ME/CFS, agreed upon by top ME/CFS specialists.

To qualify as having ME/CFS according to the CCC, you must have the following:


Fatigue:
  • Physical and mental fatigue that substantially reduces your daily activities.

Post-Exertional Malaise (PEM): (also known as PESE)
  • An inappropriate loss of physical strength and mental ability after exertion, along with a worsening of other symptoms.

Sleep problems:
  • Unrefreshing sleep, disturbed sleep patterns, or insomnia

Pain:
  • Muscle soreness or headaches

At least 2 of the following 3 neurological symptoms:
  1. Cognitive dysfunction (formerly known as "brain fog") (includes "perceptual disturbances" and blurred vision)
  2. Balance problems, muscle weakness, or muscle twitching.
  3. Hypersensitivity to light, sound, odors, cognitive stress, or emotional stress.

At least 2 of the following 3 other categories of symptoms:
  1. Dysautonomia: Including Orthostatic Intolerance (OI) (including light-headedness and extreme pallor), Irritable Bowel Syndrome (IBS) (including nausea), frequent urination, heart palpitations or arrhythmias, or breathing problems ("air hunger" or "dyspnea")
  2. Hormone problems: Body temperature problems, including night sweats, feverish feeling, cold hands or feet. Hypersensitivity to a hot or cold environment. Weight change. Stress intolerance.
  3. Immune problems: Flu-like symptoms, including sore throat or lymph node swelling. Food sensitivities or Multiple Chemical Sensitivity (MCS)

Lastly, the illness must have lasted at least 6 months.
 

Pyrrhus

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U.S., Earth
IOM/NAM Diagnostic Criteria (SEID)

IOM/NAM Diagnostic Criteria (SEID) - A basic set of diagnostic criteria that is much less detailed than the ICC or CCC, but is easier to understand. It encourages use of the term "Systemic Exertion Intolerance Disease" or SEID, instead of ME/CFS.

To qualify as having Systemic Exertion Intolerance Disease (SEID) according to the IOM/NAM Diagnostic Criteria, you must have the following:


Inability to perform your usual work, study, social, or personal activities due to fatigue:
  • There must be a substantial reduction in pre-illness activities that persists for more than 6 months. This is accompanied by new or unusual fatigue, which is often profound. Furthermore, the fatigue is not the result of overwork, and is not substantially alleviated by rest.

Post-Exertional Malaise (PEM): (also known as PESE)
  • There is a worsening of symptoms after physical, cognitive, or emotional activity. This should be more than mild and should occur at least half of the time.

Un-refreshing Sleep:
  • Feeling as tired upon waking as before going to bed. This symptom should be more than mild and should occur at least half of the time.

At least 1 of the following 2 symptoms:
  1. Cognitive Dysfunction (formerly known as "brain fog"): An inability to concentrate on tasks or process information. This symptom can be more debilitating than the physical symptoms. This symptom should be more than mild and should occur at least half of the time.
  2. Orthostatic Intolerance (OI): Symptoms include light-headedness, headaches, weakness, increased heart rate, or chest pain. Symptoms worsen upon standing, and improve upon lying down.


For more information, see:
 

Wishful

Senior Member
Messages
5,679
Location
Alberta
Technically, I never fit the ICC criteria, since I didn't have 3 of the immune/gastro symptoms, and I'm not sure that my urination frequency is enough to qualify as a symptom (maybe they need to specify frequency?). I'm not sure whether my temperature variations (and occasionally feeling feverish when body temperature is normal or even low).

I can fit the CCI by what I feel is exploiting the vagueness of the descriptions. I can fit the IOM/NAM criteria easily enough.

When I thought about it, not fitting the criteria as printed doesn't really mean much, since the criteria are very imprecise. With leprosy, you can take some patients who are clinically proven to have the bacterial infection and tally up the symptoms they have in common. With ME, a committee arbitrarily decided who would qualify as having ME. That leaves out probably a lot of people who have uncommon variations of the disease. So, all three criteria are just an imprecise tool, and should include a disclaimer about their limitations.
 

Pyrrhus

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Location
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Technically, I never fit the ICC criteria, since I didn't have 3 of the immune/gastro symptoms, and I'm not sure that my urination frequency is enough to qualify as a symptom


People who almost fit the ICC, but not exactly, are referred to as "Atypical ME" in the ICC:
ICC said:
Atypical myalgic encephalomyelitis:
Meets criteria for postexertional neuroimmune exhaustion but has a limit of two less than required of the remaining criterial symptoms. Pain or sleep disturbance may be absent in rare cases.
 
Messages
600
The first few years i had the following symptoms. I view this period as the core of my disease that has evolved conciderably since that.

Severity: Mild: i was able to continue in my full time job even if it was a constant struggle, always longing for vacation. Also i was improving month by month for the first few years but very slowly and at some point it stopped. And a few years ago i got a new crash though but im only covering the first few years after my onset here)

Fatigue
PEM
Blurry eyes, but more pronounced during PEM
Unrefreshing sleep
Early wake up/fewer hours sleep
Generall feeling of weakness
Chronic nautic dizzyness
Sore throat (mildly at least, my doc said he couldnt see it anymore though after some months even if i still felt it weakly for a very long time)
Slime production in nose area/running nose (and markedly after excertion)
Odd taste in mouth, perhaps metal-ish taste (why??)
Pain in joints and tendons - both of these only in the hands
Intestinal issues but they were present long before i got me/cfs
Reduced sensitivity to hot and cold (ambient) temperatures
Reduced ambition
Reduced interest in opposite sex (too fatigued i guess)
Reduced automatic thought generation (i used to have hyperactive automatic thoughts IMO but it became very still and calm when i crashed into me/cfs, almost a pleasure tbh)
Marked increase in drip from urinal tract after bathroom visits (i guess this is autonomic dysfunction)
Reduced feeling of intensity (e.g if i tried go for a jog it would feel like a half-dead body jogging)
Increased sound sensitivity after onset (but i had sound sensitivity since long before also)
Reduced white blood cells some months after onset, this is the only thing the doctors have found to be wrong in blood and tests, but it fixed itself somehow after some time.
Tightened muscles in the head - felt like wearing a helmet for a few years
Reduced sensitivity to light (e.g i felt like i could look in the direction of the sun if i wanted to without feeling the intensity that should come with it), but in more recent years of the disease i got screen sensitivity - so sort of opposite stuff going on here.
Feeling of hunger disappeard since onset (once in a while i can feel hunger for like a minute, that said i enjoy food just like before, its just the hunger feeling thats disappeared for some reason)
Feeling of thirst disappeared since onset
Cognition: no particular problems except i got fatigued by keeping maintained attention/concentration and i got PEM if i excert too much, for example chess would be very PEM inducing. Playing a game like Valorant that requires alot of maintained attention wouldnt have worked very well.

So what can this be, atypical me?
 
Last edited:
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79
Can someone explain why ICC uses PENE instead of PEM? Trigger of the disease is not always viral, so what is the role of immune system in delayed (or immediate) symptom exacerbation after exertion or other stimuli.

If I understood correctly, ICC requires fatigue to be flu-like, but that doesn’t mean that the problem is associated with immune system.

Also, in some mild ME cases, I believe it’s possible to never experience PEM (and these mild cases can deteriorate later, unfortunately), so person can have mild ME without matching the criteria!
 

Pyrrhus

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Location
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Can someone explain why ICC uses PENE instead of PEM?

Good question. In the English language, the word "malaise" usually refers to just a slight discomfort, so it's not really accurate to refer to PEM as "malaise". Some patients, therefore, find the term "PEM" offensive.

To replace the word "malaise", people have come up with Post-Exertional Neuroimmune Exhaustion (PENE) and, more recently, Post-Exertional Symptom Exacerbation (PESE). Personally, I prefer PESE.

If I understood correctly, ICC requires fatigue to be flu-like

I believe the ICC does not mention fatigue at all, since "fatigue" is such a vague, ambiguous concept. But they do mention "fatigability". The ICC does not require that PENE come with flu-like symptoms.

Hope this helps.
 

Wishful

Senior Member
Messages
5,679
Location
Alberta
If they come up with a reliable clinical test for ME, I wonder how many people who don't think they have ME will actually have it. I'm thinking of those people who fall in the categories of: "always sick", "lazy", "unmotivated", etc. What if a significant percentage of the population actually has some degree of ME?
 

Rufous McKinney

Senior Member
Messages
13,249
Good question. In the English language, the word "malaise" usually refers to just a slight discomfort, so it's not really accurate to refer to PEM as "malaise". Some patients, therefore, find the term "PEM" offensive.

Its fascinating that we use this term "malaise....."

Because it seems to include the notion that you cannot quite pin down what is it thats wrong. Something is wrong...and you feel this wrongness, but can't quite pin it down.

And thats perfectly applicable, oddly, to our fun disease.

Also check out the etymology......malo = BAD

So I"m developing an argument that Malaise is the Perfect Term for this:

Where does the word malaise originate from?


malaise (n.) c. 1300, maleise "pain, suffering; sorrow, anxiety," also, by late 14c., "disease, sickness," from Old French malaise "difficulty, suffering, hardship," literally "ill-ease," from mal "bad" (see mal-) + aise "ease" (see ease (n.)).

I see nothing "slight" about our Malaise.
 

wabi-sabi

Senior Member
Messages
1,458
Location
small town midwest
Going on a rant here, because insomnia, cognitive, dysfunction and generalized despair.

Here's my unpopular opinion. I think the ICC criteria is wrong, due to over-nitpicking. It's got to be wrong since I don't meet it, and it is all about me. I meet IOM and CCC criteria.

So severe I have had to give up my career. Had to drop out of grad school due to cognitive dysfunction. Moving back into my parents' house since I am becoming bedridden and unable to care for self.

But sore throat and swollen glands? Nope.
Persistent infections" how would you even know, esp in light of people not even being able to verify reactivated EBV?
IBS? nope. but yes to difficulty swallowing, acid reflux, and gastroparesis.

I know there's a spot for "atypical ME" in the ICC, but I don't feel like I am atypical, based on what I hear here.

The ICC is wrong. Fight me. "Cause it is all about me. :)
 

Pyrrhus

Senior Member
Messages
4,172
Location
U.S., Earth
Related research on diagnostic criteria:

Contrasting Case Definitions: ME International Consensus Criteria vs. the Fukuda et al. CFS Criteria (Brown et al., 2013)
https://forums.phoenixrising.me/thr...teria-vs-the-fukuda-et-al-cfs-criteria.24865/


The importance of a research case definition (Jason et al., 2017)
https://forums.phoenixrising.me/threads/the-importance-of-a-research-case-definition.55300/

ICC vs. Fukuda: Diffusion tensor imaging results differ based on diagnostic criteria (Thapaliya et al., 2021)
https://forums.phoenixrising.me/thr...agnostic-criteria-thapaliya-et-al-2021.85111/