Talk:Post-exertional malaise

Changes to lead -- Pwc (talk) 02:07, May 22, 2022 (UTC)
I'd like to change the first part of the lead from "Post-exertional malaise (PEM) refers to a worsening of ME/CFS symptoms after minimal physical or mental exertion, which can be delayed 24-72 hours or more" to "Post-exertional malaise (PEM) refers to a worsening of ME/CFS symptoms after physical or mental exertion which may be minimal, and which can be delayed 12-72 hours or more. The delayed nature of PEM is regarded as a key feature of it." Bold added by Njt to highlight changes (and further adjusted by pwc)

The reason for the adjustment to the word minimal is that I think it may cause some confusion. Everyone has a different definition of minimal, and the use of the term there may lead people to believe that if someone can still engage in some minimal activities without PEM, that can't be ME/CFS. I'm also concerned that it may give the impression that PEM means it is impossible to engage in activity that isn't minimal, when the delayed nature of PEM means that it is often possible for people to engage in substantial activities, but only prior to PEM starting. The word "minimal", or an equivalent, also isn't used in most definitions of PEM, including the ones that are cited in that sentence.

The second change, adding “The delayed nature of PEM is regarded as a key feature of it.” is because the delayed nature of PEM is widely regarded as a defining feature of it, and many definitions, such as the CDC one here, either say it is typically delayed or emphasize it as a feature.

The third change, changing "24-72" to "12-72" is because the CDC definition says PEM typically occurs after "12-48" hours, so I think that lower bound should be included.

The definition of PEM is important so I thought I'd explain my changes and check for any objections. Thank you --Pwc (talk) 02:07, May 22, 2022 (UTC)


 * Hi User:Pwc. You raise some good points. In tagging some active contributors but will share on the MEpedia Slack channel too User:Kmdenmark, User:JaimeS, User:Violet202, User:Hip. The lead could do with an update but at the moment I don't see a reference that states that the core part of it is the delay itself - do you have one?
 * On point 3 - I think 24-72 hrs is a rephrasing of 1 to 3 days perhaps... but "up to 3 days" might be clearer. Jason's PEM article actually states that the duration of PEM is more significant (when comparing with other illnesses where patients may have PEM), he sets a minimum of 14hrs of PEM, plus also despite the name his research says PEM can occur immediately or be delayed - and we know some people do physically collapse if they ignore warning signs (MP Brynmor John at the gym). Deconstructing PEM mentions the delay in symptoms as significant but most sources on PEM say only "may be" delayed.. In very severe ME there is often constant / rolling PEM, so it isn't possible to say it is delayed since it's hard to work out if PEM is from the day before or 2 days before, last week, or earlier in the day etc. I looked up the 2 References cited at the moment - Arroll2014 just includes the mental activity not just physical - other other ref is the main CDC page. Emotional triggers of PEM are excluded (eg laughter, fun, stress) but are not in the main CDC definition and there may be mixed feelings about including psychological factors. I did find some other definitions that we could include parts from that might emphasise the point that I think you are making:
 * 1. CDC Treating most disruptive symptoms
 * "Post-exertional malaise (PEM) is the worsening of symptoms following even minor physical or mental exertion, with symptoms typically worsening 12 to 48 hours after activity and lasting for days or even weeks.
 * To me, this captures core of PEM and avoids confusion with simple aches, pains and tiredness that many healthy people get


 * 2. CDC symptoms
 * This is known as post-exertional malaise (PEM). People with ME/CFS often describe this experience as a "crash," "relapse," or "collapse." During PEM, any ME/CFS symptoms may get worse or first appear, including difficulty thinking, problems sleeping, sore throat, headaches, feeling dizzy, or severe tiredness
 * We could say something like:
 * "Post-exertional malaise (PEM) refers to a worsening of ME/CFS symptoms —a "crash," "relapse" or "collapse"— caused by minimal physical or mental exertion, which can be delayed 24-72 hours or more."


 * 3. PMC6165517 A Brief Questionnaire to Assess Post-Exertional Malaise L Jason 2018
 * One of its working groups focused on post-exertional malaise (PEM), a core symptom of ME and CFS. PEM involves an abnormal response (e.g., an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability) following physical, cognitive, emotional, or orthostatic exertion [2,3,4].
 * I think I prefer this definition because of the abnormal response. It rules out deconditioning in bedbound people for example.


 * 4. NIH/CDC Common Data Element (CDE) committee’s PEM working group definition:
 * "an abnormal response to minimal amounts of physical or cognitive exertion that is characterized by:
 * (1) Exacerbation of some or all of an individual study participant’s ME/CFS symptoms.
 * (2) Loss of stamina and/or functional capacity.
 * (3) An onset that can be immediate or delayed after the exertional stimulus by hours, days, or even longer.
 * (4) A prolonged, unpredictable recovery period that may last days, weeks, or even months.
 * (5) Severity and duration of symptoms that is often out-of-proportion to the type, intensity, frequency, and/or duration of the exertion.”
 * Honestly, I find this too long and since orthostatic intolerance is optional and not found in other definitions, I think it's best left out.


 * To me, the resulting symptoms are very significant - PEM is not Delayed Onset Muscle Soreness - immune symptoms such as sore throat, and significant brain fog while doing trivial things like watching TV are key, but there are examples that can be added for that.


 * A decision tree or flowchart further down might be helpful - I don't mind making one - Jason 2018 Appendix B states that PEM is only present if:
 * a) One or more of 5 symptoms are part of it (Dead, heavy feeling after starting to exercise; Next day soreness or fatigue after non-strenuous, everyday activities; Mentally tired after the slightest effort,; Minimum exercise makes you physically tired; Physically drained or sick after mild activity)
 * AND the symptom occurs at least half the time
 * And with moderate severity or worse
 * b) worsening of your fatigue/energy related illness after engaging in minimal physical effort
 * OR worsening of your fatigue/energy related illness after engaging in minimal mental effort
 * c) PEM symptoms last 14hrs or longer


 * My idea of "minimal" activity is way lower than most people's, I think minimal means the kind of thing that the average person thinks is minimal. I think that's best dealt with in examples, but I think "mild" would be a better choice than minimal.


 * Jason (2018) - and of course his PEM Questionnaire - do say that people do not need to have PEM after every minimal activity - they say "about half of the time" or more - so this could be included possibly in a second sentence. Recently I looked up definitions for mild ME/CFS so some wording there may be helpful, or mentioning the fluctuating nature of the illness in most people means PEM and other symptoms can't always be predicted.


 * I will post on Slack for feedback from others. To sum up I would like: minimal to stay where it is (or replace with mild), add in that PEM is an "abnormal response" to the level of exertion, crash/collapse could be added to emphasise the crushing nature of PEM based on people's typical descriptions, change 24-72hrs to "up to 3 days", consider adding add in that PEM typically worsens after 12-24hrs.


 * I will post back after others reply on Slack, email the main MEpedia email if you want to be added to the Slack channel. ~Njt (talk) 01:16, May 23, 2022 (UTC)
 * Hi, thank you for the response. I'm flexible about the specific way that it might be phrased, really there's just two points that I want to capture - I want to avoid the possible confusion from the word "minimal", for the reasons I mentioned, and I want to emphasize either that it's typically delayed, or that it's regarded as a key feature. So I'm happy with almost anything that addresses those two conerns. I'm not concerned about the "mental or physical" exertion part - I don't think that should be changed.


 * I'm not suggesting saying that it being delayed is "the" core part of it, rather that it is a "a" key feature. Which is true - It is one of the key features mentioned in the CDC and NICE definitions, and there are more references under the Timing heading in the article. I just want to emphasize in some way that it's regarded as a important feature of it in some way - I would be happy with just saying "typically delayed", "can be typically delayed" or anything along those lines. I would also be happy with "up to 3 days" - that's fine.


 * The NICE defintion of PEM is "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."


 * It's very similar to the CDC definition. Neither of the definitions outright say that it follows minimal exertion - NICE says it "can" follow, and the CDC says it follows "even" minor exertion. So I would prefer something along those lines that just softens it a bit in some way like "even" or "can" or "may be minimal". I don't mind the particular adjective - minor, minimal or mild would all be good. I don't think saying that it follows minimal activity about half the time should be done, since Jason doesn't actually explicitly say that's the case, it's just a feature of his questionnaire (and 97% responded at least half to at least one of five PEM symptoms, each symptom category refers to symptoms after different activity types, so not half of all activities) - and there's still the issue that it's unclear what minimal means. But that result could be included, as it's reported in his article, but maybe not in the lead since it's just one result and it has some caveats. I also would prefer the word "follow" or "after" rather than "caused by" (causation is a strong claim).


 * I also have no objections to including "Abnormal response" or "crash/collapse". And a flowchart further down sounds like it could be good.


 * So, as an example, adjusting what you suggested, it could be "Post-exertional malaise (PEM) refers to a worsening of ME/CFS symptoms —a "crash," "relapse" or "collapse"— following even minimal physical or mental exertion, which can be typically delayed 24-72 hours or more."--Pwc (talk) 03:28, May 23, 2022 (UTC)


 * Hi. Sorry for such a show reply. What do you think of this wording below instead User:Pwc? Minimal is gone but we can easily include that in a subheading and explain sometimes only minimal exertion is needed to cause a crash. Feel free to reword. Bold is there only to show changes, not to show formatting on final version.

Post-exertional malaise (PEM) refers to a worsening of ME/CFS symptoms and/or the appearance of new symptoms after physical or cognitive exertion which was previously tolerated,[1][2]] and is often delayed 24-72 hours or more.[3][4][5][6] PEM is considered to be the hallmark symptom of ME/CFS, and interferes with the ability to lead a "normal" life.[7][8]] While in most fatiguing diseases patients experience symptom relief after exercise,[9][10][11][12] the opposite is true for ME/CFS patients for whom even minimal exertion may cause PEM.[13]


 * I have only heard from User:JaimeS elsewhere, I can add her comments in although it's quite long. I talked with her and we came up with this which I hope addresses the minimal effort and delayed PEM points you raised, plus several User:JaimeS and I had too. JaimeS also mentioned the effect of previous exertion contributes (it's cumulative exertion), although I can't recall seeing a reference for that and it's not in the coming used definitions. I'm happy to do a flowchart or similar once the lead is agreed on. ~Njt (talk) 20:45, June 10, 2022 (UTC)


 * User:Notjusttired I think that looks good! Thank you for taking account of my concerns.


 * A separate issue is I think the sentence about the effect of exercise on other fatiguing illnesses and its citations could be improved, since exercise can cause symptoms for many other fatiguing illnesses (not like PEM though), and it's unclear whether it's talking about the very short, short, or longer term effects of exercise. However, I'm uncertain how that sentence would be best improved, so I might just think about that. You can go ahead and add the new lead though --Pwc (talk) 00:59, June 13, 2022 (UTC)

Second paragraph
The paragraph below is confusing and doesn't have a source so it's a bit hard to figure out what it is saying. I think it might be saying that the post-exertional malaise symptoms are a worse version of whatever the other symptoms in the diagnostic criteria are? That doesn't entirely make sense since the criteria don't say "only these symptoms count as PEM". Also I think it's pretty obvious that symptoms in the diagnostic criteria are those commonly made worse or caused by PEM. This paragraph wasn't as prominent until I put others under subheadings to improve readability, and I couldn't think of an obvious heading or topic it was about. It could go back on the page with a source, but lower down and I'm not sure where would be best? "Symptoms caused by PEM" could be a heading but there would be specific research about the most frequent symptoms for that. ~Njt (talk) 00:42, January 30, 2022 (UTC)

"Depending on the criteria a patient meets (Systemic Exertion Intolerance Disease (SEID) for ME/CFS's minimum core symptoms, the Canadian Consensus Criteria (CCC) for this criterion's ME/CFS symptoms, or the International Consensus Criteria (ICC) for myalgic encephalomyelitis (ME) and its ME symptoms) will correlate with the patient's symptoms that will worsen."

Executive summary wanted
Is it possible for there to be an executive summary that captures the concept? I find the concept to be confusing and the page is too long for me to read. I realize this might not be possible.

This sentence does not parse for me: "Depending on the criteria a patient meets (Systemic Exertion Intolerance Disease (SEID) for ME/CFS's minimum core symptoms, the Canadian Consensus Criteria (CCC) for this criterion's ME/CFS symptoms, or the International Consensus Criteria (ICC) for myalgic encephalomyelitis (ME) and its ME symptoms) will correlate with the patient's symptoms that will worsen." Remove the parenthetical comment and it is apparent. But I do not know what to replace it with.

Added A Paragraph Of Which Symptoms Worsen And The 24-72 Hour Delay. I Have PEM But Charts And Graphs Don't Tell Me What I "Feel" And When It Happens and I don't even know, from an average patient and general public reader point of view, what PEM is. Although these are not studies relating this information on the symptoms and the 24-72 hour delay (there may be and they may be in the charts and posted in the page somewhere) the average reader won't come away with much of an understanding if a short blurb is not included as to what it feels like and patient reporting on the worsening symptoms and when. Since it is "the marker" and "core symptom" little understood by patients, caretakers, the medical field, etc., I thought it best to include a brief explanation. I also included a new post under "Learn More" as i feel this page correctly and succinctly defines PEM.

Also, there are 3 citation errors and if I can I will try to correct. My edit did not create them as they were there prior to my edit.--DxCFS (talk) 08:54, 16 August 2016 (PDT)


 * Although this was years ago, I felt similar when I looked to edit for another reason today. I have now added subheadings and shortened the very start. ~Njt (talk) 00:42, January 30, 2022 (UTC)

Moved citations
I have moved two citations not used in prior text from the references section to here. If you can figure out where in the article these citations should be used, please move them back.--Samsara (talk) 08:42, 7 November 2016 (PST)
 * These are on the page now.

Visual editor
The visual editor seems to be getting "stuck" as it is a pretty big page now. Perhaps breaking off notable research to its own page will help. I will leave it to others to make that decision.--MEcfsFMS (talk) 21:34, 15 October 2018 (EDT)

PEM
PEM is usually delayed 24-72 hours and I did an undo on a revision that removed that information.--MEcfsFMS (talk) 09:22, 17 October 2018 (EDT)


 * PEM is usually delayed 24-72 hours. My whole world fell into place when I learned that information. Studies, ME/CFS organizations, and patients are reporting this delay and are in agreement.


 * Additionally, patients and ME/CFS advocacy groups have been requesting testing (CPET and other measurements) be done 48 and 72 hours out because of the delay and they want PEM captured several days out when it onsets. --MEcfsFMS (talk) 09:39, 17 October 2018 (EDT)
 * This is now in the lead ~User:Notjusttired (talk) 21:55, June 10, 2022 (UTC)