Evergreen
Senior Member (Voting Rights)
@MinIreland, this is by no means comprehensive, but will give you an idea.
The quote below is one of two that Jonathan referred to as misinformation above. The fragility of the evidence linked to in the International Consensus Criteria is dealt with elsewhere on S4ME. Jonathan and Kitty have covered some of the big picture issues with the Facebook post. I'm going into the nitty gritty.
I've highlighted some problematic parts of the Facebook post quoted above, and explained some of the issues I see:
Here's what the International Consensus Criteria actually say:
Here's what the NICE guideline actually says:
Here's what Fluge et al. actually say:
So if someone reads the Facebook post and takes it at face value, they're being misled.
Hope this helps.
The quote below is one of two that Jonathan referred to as misinformation above. The fragility of the evidence linked to in the International Consensus Criteria is dealt with elsewhere on S4ME. Jonathan and Kitty have covered some of the big picture issues with the Facebook post. I'm going into the nitty gritty.
I've highlighted some problematic parts of the Facebook post quoted above, and explained some of the issues I see:
People often use the term “post-exertional malaise” or PEM when talking about what happens after exertion in Chronic Fatigue Syndrome (CFS). But what defines Myalgic Encephalomyelitis (ME) is not just malaise or tiredness — it is Post-Exertional Neuroimmune Exhaustion (PENE). The two terms sound similar, but they describe very different experiences and biological processes. [No, they don't. The ICC coined the term PENE to replace PEM, not as something to be distinguished from it, because they were trying to propose specific pathophysiology underlying PEM.]
Post-Exertional Malaise (PEM) — in CFS [This author is trying to create a distinction between CFS and ME, where CFS is trifling and ME is serious. They're trying to bolster this by saying that PEM is trifling but PENE is serious, so CFS only has PEM but ME has PENE. These distinctions are simply made up.]
In CFS, PEM generally means feeling worse after doing too much. A person might feel more fatigued, achy, or mentally foggy for a while. It’s unpleasant, but it’s often viewed as a temporary increase in symptoms, similar to what healthy people feel after overexertion — only stronger and longer-lasting. It usually improves with extra rest.
Post-Exertional Neuroimmune Exhaustion (PENE) -ME
In ME, the reaction is far more severe and far more dangerous. PENE means that the nervous system and immune system become pathologically overactivated [very shaky evidence] and then fail to recover after even very small amounts of activity; physical, mental, or emotional. This is not just feeling more tired. It is a full neurological and immunological crash [no evidence]. The exhaustion of PENE is not ordinary fatigue. It feels like the body’s energy system has been “shut down.” People may feel paralyzed, poisoned, or flu-like, and can become bedbound or unable to speak, move, or think clearly.
It can take 24 to 72 hours or more after the activity for the crash to appear, and recovery can take days, weeks, or months. During PENE, there is measurable evidence of biological change [all either shaky or not true]:
* The nervous system shows reduced brain blood flow and poor communication between brain regions.
* The immune system shows abnormal cytokine responses as if the body is fighting an infection that isn’t there.
* The cellular energy system (mitochondria) cannot produce energy normally, and lactic acid builds up in the muscles.
* The autonomic nervous system loses control of heart rate, blood pressure, and temperature, leading to dizziness, chills, or flushing.
Even very small activities — like brushing teeth, talking for too long, or sitting upright — can trigger this crash. The worsening is disproportionate to the effort and is not relieved by rest or sleep.
This distinguishes ME from CFS. {No, it does not. People who are given the label CFS are not less sick than people given the label ME. They have just seen a different doctor. ]
Summary in Simple Words
*Post-Exertional Malaise in CFS means “I feel worse after I do things.” *Post-Exertional Neuroimmune Exhaustion in ME means “My body crashes after even tiny efforts because my brain, nerves, and immune system can’t recover.”
*PEM is a symptom. *PENE is a systemic breakdown. [Fabrication and deeply unhelpful when the whole international research community is using the term PEM. The grain of truth is that PEM has been defined by some in a way that makes it simply mean pathological fatigue after activity, and it would be a good idea to do research to figure out how post-exertional phenomena differ in ME/CFS and other diseases.]
...
In Myalgic Encephalomyelitis (ME), Post-Exertional Neuroimmune Exhaustion (PENE) is not just feeling tired after activity. It is a biological crash [we've little or no idea what is happening biologically during PEM] in which the nervous system, immune system, and energy metabolism are all overwhelmed.
...
International Consensus Criteria for ME (2011)
* Carruthers, B. et al. Myalgic Encephalomyelitis: International Consensus Criteria.
* Key point: This paper explicitly distinguishes PENE from fatigue or PEM, describing it as the hallmark symptom of ME and warning that overexertion can cause severe, long-lasting crashes
https://pubmed.ncbi.nlm.nih.gov/21777306/ [The author has misunderstood the paper. The authors replaced the term CFS with ME and replaced the term PEM with PENE, both with the intention of underlining their seriousness. The authors of the ICC overstated the evidence.]
National Institute for Health and Care Excellence (NICE) – 2021 Guideline for ME/CFS
* NICE recognizes post-exertional symptom exacerbation (PESE) as a key symptom. [No, they recognise PEM as a key feature, and say PEM can also be called PESE (note not PENE). This is at least understandable, as the draft guideline did use PESE instead of PEM.]
* They caution that overexertion can worsen illness severity and cause long-term decline, aligning with the concept of PENE.
https://www.nice.org.uk/guidance/ng206
Educational Articles / Reviews
* Newton JL, et al. Management of ME: recognizing post-exertional neuroimmune exhaustion. [I cannot find an article by Newton with this title online. The article linked to two lines below is called "PENE is Post Exertional Neuroimmune Exhaustion". It does not list any authors. It does not read like something written by Newton. At one point "we" is used, and then a study by Chu et al. is linked, which is a study of PEM in ME/CFS using Fukuda criteria.]
* Explains why PENE is different from fatigue and why pacing and rest are essential for preventing long-term harm. https://25megroup.org/.../PENE-is-Post-Exertional... [See above.]
* Fluge Ø, et al. Evidence of metabolic dysfunction and post-exertional crash in ME. [Fluge et al. do not have a study with that title. The study linked is actually entitled "Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome". See the switch between ME and ME/CFS?]
* Discusses biological mechanisms behind PENE, showing it’s not psychological or voluntary. [The study does not mention PENE. It mentions PEM. In ME/CFS.] https://pubmed.ncbi.nlm.nih.gov/28018972/
Here's what the International Consensus Criteria actually say:
The label ‘chronic fatigue syndrome’ (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation
and multisystemic neuropathology, it is more appropriate and correct to use the term ‘myalgic encephalomyelitis’ (ME) because it indicates an underlying pathophysiology.
Here's what the NICE guideline actually says:
Post-exertional malaise
The worsening of symptoms that can follow minimal cognitive, physical, emotional or social activity, or activity that could previously be tolerated. Symptoms can typically worsen 12 to 48 hours after activity and last for days or even weeks, sometimes leading to a relapse. Post-exertional malaise may also be referred to as post-exertional symptom exacerbation.
Here's what Fluge et al. actually say:
The main symptoms of ME/CFS are fatigue, postexertional malaise, and lack of adequate restitution after rest or sleep, accompanied by cognitive disturbances and sensory hypersensitivity, including pain.
In conclusion, this study suggests that ME/CFS is associated with PDH impairment, leading to increased consumption of amino acids that fuel alternative pathways for ATP production. ME/CFS patient serum was found to increase mitochondrial respiration in cultured muscle cells, possibly as a compensation or adaptation to an inhibition of metabolic energy pathways. The physiological consequences of such defects are likely to include energy (ATP) deficiency and excessive lactate production, in agreement with the debilitating exertion intolerance seen in ME/CFS patients.
So if someone reads the Facebook post and takes it at face value, they're being misled.
Hope this helps.
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