Is the NIH/CDC going to use the right PEM definition for all their future research? Do patients need to act? Deadline 31 Jan

[Alice]

The way the symptoms are scored might give misleading results

My other big concern with the questionnaire, which again relates to its accuracy, is about how PEM is scored. I think we need to score in a way that reflects how patients try very hard to avoid PEM. Here’s the questioin

“For the following questions, we would like to know how often you have had each symptom and how much each symptom has bothered you over the last 6 months.“ Each is scored 0-4, and a PEM diagnosis requires a score of at least 2 on both frequency and severity for any of the 5 items. These scores corresponds to at least moderate severity and PEM half of the time or more.

I think the frequency question looks at things the wrong way, and am pretty sure there are plenty of mecfs patients with PEM who experience it less than half the time - and so who would be excluded from every NIH/CDC study.

The problem is that PEM is a function of disease level, but also of pacing and life circumstances. As the report note elsewhere, “many ME/CFS patients use strategies to avoid and/or to minimize the impact of PEM”.

The subgroup is clearly aware of the problem, with the case report form emphasising the need for researchers to interpret the questionnaire finding:

“In making this [PEM] determination, the researcher or clinician will need to consider whether there are other conditions, such as overwork, that could result in a false positive DSQ PEM subscale response. On the other hand, the researcher or clinician should also consider whether the study participant responded negatively because, for instance, they carefully manage their energy expenditures with pacing to avoid episodes of PEM.

In addition to asking questions about workload and pacing, the researcher may also ask what happens to the study participant if/when they engage in physical or mental activity and whether there are activities they avoid because it exacerbates symptoms.”

This is all very good, and important.

But I think we need a questionnaire that allows the patient to give more appropriate information in the first place. This could be with a question on what happens if/when they engage in physical or mental activity. Or to what extent the patient has to change their life to avoid PEM – I suspect that for most patients it’s “a great deal”, and any questionnaire should capture that.

A major reason for a mandatory questionnaire across studies is to standardise approaches, whereas relying on researcher judgement to interpret questionnaire scores will do the opposite.

Again, my views – what do other patients think?

Thanks for your patience with my long posts. Please bear in mind that the consultation document ran to 28 pages. And thanks for all work done by the PEM subgroup.

I know when I was less severely ill and didn't know any better I still exercised. I could exercise at that point, but as you say @Barry , the aftermath was very,very different.

The more I tried to exercise the worse it and less able to exercise I became. This is the opposite of my experience of exercise prior to becoming ill.

When healthy the post exercise aches could often be eased by gentle exercise and movement. With PEM I found, when I was still well enough to try, further exercise and movement made the symptoms rapidly worse.

I've found that I can enjoy and feel good after exercise despite the fact that I will suffer PEM later in fact the more I overdo it the more enjoyable it is at the time. Doing my CPET test was marvellous. The 7 month severe crash afterwards was not. PEM can last YEARS/DECADES.

 

[Sasha]

I've found that I can enjoy and feel good after exercise despite the fact that I will suffer PEM later

Me too. I feel great while I'm overdoing it. I have no idea until later (apart from prior experience) that I've gone beyond my limit.

 

[Invisible Woman]

I've found that I can enjoy and feel good after exercise despite the fact that I will suffer PEM later in fact the more I overdo it the more enjoyable it is at the time. Doing my CPET test was marvellous. The 7 month severe crash afterwards was not. PEM can last YEARS/DECADES.

Sometimes yes, sometimes no.

For me there are phases to this condition that are separate to PEM. There a good phase (a rare thing now). When it seems quite stable and I can enjoy small yoga type exercise & very gentle walks.

There is the downward phase where no matter what I do my condition and overall function drops off.

There is the bad phase.

Then (hopefully) the improving phase - where if I'm careful and avoid becoming breathless I can exercise a little. With great caution.

Depends on the phase.

 

[Indigophoton]

?? but there is not a hard physical ceiling. It appears that PEM fluctuates

Yes, I meant that our functional capacity has a real, irremovable, lowered ceiling, depending on level of severity, not that PEM itself is fixed.

 

[Alice]

Defining PEM is easy but measuring it subjectively and its frequency can be meaningless and fraught with misinterpretation. The NAM description seems accurate and it and the IOM description don't get bogged down in symptom lists. The key to a PEM definition in my opinion is its overall characteristics and the potential triggers. The NAM and IOM fail to identify all the triggers...= that exacerbate the symptoms e.g. major intolerances to chemicals, foods, light noise, vibration, sensory overload etc these triggers can be much harder to identify and control than physical/cognitive exertion and lead to the view that PEM is random and/or unavoidable. Jason, Klimas etc all state that the more severe patients often have less symptoms. Obviously not because they are healthier but because they have learnt to avoid PEM triggers severe end of the spectrum are missing from ALL existing diagnostic criteria so far. PEM shows up on heart rate traces it can be objectively seen and measured by patients. A descriptor for PEM is all we have right now but maybe the real work needs to be done on validating/measuring/comparing the changes in the HR traces of people in and out of PEM? Maybe bedridden/housebound people are the best to use or maybe the bedridden/housebound people are different but certainly in this group the orthostatic variation in HR is markedly greater on a PEM day as is the heart rate variation (spikiness of the HR trace) throughout the day. The NICE Guideline may need to suggest things that might help/patterns that some patients have reported that others may use. The Royal College boffins will turn to the published papers by their mates and meta analyse them yet again ignoring that garbage in = garbage our. We need to be creative about how we want our perspective to be included when the patient story has been ignored and we don't have research to back us. Our experiences can still be included under headings such as patient findings yet to be tested by research....expansion of the heart rate pacing section of NICE.

 

[Wonko]

Defining PEM is easy....

Is it? I can't. I experience it, more frequently than I'd like, I remember bits, but only bits, of it. Through reading others experiences I recognise and through this recognition temporarily remember forgotten bits of my own PEM.

But a complete definition, that's beyond me.

I assume the difference between people who think they can define it is down to the relative level of cognitive issues experienced, but as these, at least for me, are also part of PEM, how can someone who doesn't have this level of cognitive impingement come up with a complete definition of PEM, and if they do, like me, they can't.

It's not easy.

Or other words that mean something more sensible.

 

[Indigophoton]

the more severe patients often have less symptoms. Obviously not because they are healthier but because they have learnt to avoid PEM triggers

Except that at the very severe end of the spectrum, avoiding triggers is simply impossible, by virtue of still being alive. For example, noise, light, being moved by others (for washing, bed sheet changing etc), and other things one cannot eliminate are enough to cause PEM at that level.

 

[Keela Too]

I haven't read this whole thread yet (I probably should) but this is the comment I added to the questionnaire:


Jane Colby suggests "Post Exertional Deterioration" instead of "malaise".

I like this idea, as "malaise" is a word that suggests something fairly minor. "Deterioration" on the other hand, does not seem like a minor issue.

When I was most ill, small exertions led to a deterioration that did not allow me to return to the same level of functioning as before. Each error of judgement (where I did just a tiny bit above my incredibly low threshold) caused a further lowering of my long term capacity.

In truth, after recovering from the immediate dip in ability, I lost only small fraction of my total well-being each time, but the overall effect of these minor "over exertions" was a ratcheting downwards of my health over several years.

Naturally, I became very cautious about exertion or stimulation of any kind, and never pushed on to the point where I was "tired". Yet still I couldn't quite control the downward descent.

For this reason I very much dislike the word "fatigue" - in truth I rarely could feel properly tired. I couldn't do enough to feel that genuine tiredness, because doing so would cause the dreaded post exertional deterioration, and so I always had to curtail my activities before I got to the point of tiredness.

I think every exertion assessment should properly assess three things:
The immediate effects as exertion happens
The delayed effects in the days afterwards
The long term outcome of the exertion incident.

Note: Fortunately I have since improved after a drug treatment. And, I've had no problem taking up the additional capacity that my improved health has now offered me. (No GET required!)

Unfortunately, I now have a new exertion threshold, and I am still careful not to challenge it. I really don't want to start loosing functioning as I did before. Meh.

No need to reply to this.
Sally

 

[susanna]

I agree with a great deal of what's been said here, and want to second my thanks for raising it. I'm not really sure how to move it forward, though. I decided to try laying out a questionnaire about specific symptoms, including some that aren't really typical of ME (in my case, at least). It's quite a difficult task, but I wondered if it's worth considering? I'm sure many of us have been subjected to similar mental health questionnaires over the years, and clinicians trying to assess people for mental ill-health do seem to find them useful.

This is in no way a comprehensive list, as my brain function isn't really good enough to tackle it at the moment, but I thought I'd post it to see if folk think it could be helpful. I don't mind if you don't; the best way for us to make progress is to eliminate strategies which are either too easy to pull apart, or too unspecific to be useful. Here goes – the symptoms in italics are the ones that aren't typical of my experience of ME:

PHYSICAL

Types of physical movement likely to trigger symptoms – please tick all that apply, and cross out any you are unable to do at all:

· Walking inside house/apartment
· Walking outdoors
· Sitting upright
· Eating
· Light household cleaning
· Reading
· Speaking
· Washing
· Use of computer, tablet or phone
· Writing
· Dressing

Symptoms resulting from physical movement – please tick all that apply:

· Twitching muscles
· Muscle pain
· ‘Foggy’ thinking or confusion
· Swollen glands
· Pins and needles
· Prolonged exhaustion
· Headache or migraine
· Burning sensation in limbs
· Knee pain
· Upset stomach
· Feeling as if you have ‘flu
· Greater sensitivity to light
· Greater sensitivity to noise
· Decreased ability to socialise
· Low mood
· Difficulty with reading/fine focus
· Poor short-term memory

Average time before onset of significant symptoms after physical movement – please tick one:

· Immediate
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

Recovery time from symptoms triggered by physical movement

· Less than 2 hours
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

MENTAL

Types of mental effort likely to trigger symptoms – please tick all that apply, and cross out any you are unable to do at all:

· Reading
· Watching TV
· Listening to radio, podcasts or audiobooks
· Conversation with another person
· Worrying or anxiety
· Use of computer, tablet or phone
· Hearing music
· Pressure to socialise
· Having a familiar person in the room with you

Consequences of mental effort – tick all that apply:

· Headache or migraine
· Prolonged exhaustion
· ‘Foggy’ thinking or confusion
· Low mood
· Greater sensitivity to light
· Greater sensitivity to noise
· Feeling as if you have ‘flu
· Muscle tension
· Decreased ability to socialise
· Poor short-term memory
· Feeling irritable

Average time before onset of significant symptoms after mental effort – please tick one:

· Immediate
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

Recovery time from symptoms triggered by mental effort:

· Less than 2 hours
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

ENVIRONMENTAL

Types of environmental stressors likely to trigger symptoms – please tick all that apply, and cross out any you are unable to tolerate at all:

Visual

· Sunlight
· TV, computer, tablet or phone screen
· Other people
· Indicator lights on electrical appliances
· Fluorescent lights

Hearing

· Ticking clock
· People talking
· TV
· Fan
· Telephone ringing
· Traffic
· Music

Olfactory (smell)

· Volatile chemicals such as paint, perfume, cleaning products, gasoline/petrol
· Cooking food
· Domestic pets

Consequences of experiencing environmental stressors – tick all that apply:

· Headache or migraine
· Prolonged exhaustion
· Nausea or vomiting
· ‘Foggy’ thinking or confusion
· Low mood
· Feeling as if you have ‘flu
· Decreased ability to socialise
· Muscle tension
· Poor short-term memory
· Feeling irritable

Average time before onset of significant symptoms after experiencing environmental stressors – please tick one:

· Immediate
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

Recovery time from symptoms triggered by experiencing environmental stressors

· Less than 2 hours
· 2 – 6 hours
· 6 – 12 hours
· 12 – 24 hours
· 24 – 48 hours
· More than 48 hours

Yes, Kitty, I agree we need a more expanded list. After all, research is to be based on this.

 

[susanna]

The danger is we start defining PEM as “whatever it is that separates us from every other diseases” rather than focusing on what are the common experiences of patients with this illness in response to exertion. The fact that the " spoonie" idea is so popular suggests our issue may not be unique. I think it genuinely needs more work to explore that, but that shouldn’t stop us making sure that the N I H/CDC define our experience accurately.[/QUOTE][/QUOTE]
If we demonstrate our common experience in sufficient detail this should help to delineate unique features of the disease.

 

[susanna]

I very much appreciate all the thought given to trying to describe PEM, and as is evident, this is a challenging task, and our group has been dealing with these issues for many years, using quantitative, qualitative and mixed method approaches. I generally do not post my thoughts on these sites, but thought this time, it might be useful to do so. At the end of this post, we provide references to some of our work in this area, and how those publications can be accessed for those that want more details of our path. We do have many other articles that deal with PEM, but this is a sample of the types of work our group has been doing, some of it dating back to the mid-1990s. Certainly, getting feedback is helpful, and we think that continuing efforts to define this critical symptom is important for the field.


Madison Sunnquist and I have read through the thread, and it seems like there are 2 main categories of criticism regarding our work:



Critique 1: The DSQ symptoms don’t reflect their experiences of PEM (e.g., PEM might involve flu-like symptoms, as opposed to muscle soreness or fatigue; some individuals focused on the delayed onset feature of PEM, though we do have an item that mentions ‘next day’ soreness). Even though each individual symptom might not reflect the varied presentations of PEM, in our large sample (>1,000 individuals with ME), 95.4% reported PEM (ie, had at least one of the symptoms at a frequency/severity >=2), so it does appear that, overall, we’re capturing most individuals in our samples. Additionally, in our DSQ 2.0 (which we have been working on for the past year), we’ll be adding the following symptom (based upon one of our study’s participatory PEM research) that seems to be more consistent with many of the suggestions we saw in the threads: “Worsening of symptoms after mild activity.” According to one of our RA’s work, 93.8% of our participants with ME endorsed this symptom (f/s>=2/2), but almost all of these individuals had also endorsed one of our original PEM items as well.



Critique 2: Individuals might not experience PEM if they pace. This is a good point, and have considered treating our PEM items in a similar manner to how we changed our alcohol intolerance item. For example, we could preface the statements with, “If you were to engage in activity…” Despite this critique, as we mentioned above, most participants still report significant PEM; our thought is that this is due to the 6-month timeframe (it seems like it would be exceptionally difficult to pace consistently for half of a year).

If you go to this site: https://www.researchgate.net/ then, do a search on my name (Leonard A. Jason) and when you get to my cite, request full text of any of the articles below, and I can send you via researchgate a private copy.


McManimen, S. L., Sunnquist, M. L., & Jason, L. A. (in press). Deconstructing post-exertional malaise: An exploratory factor analysis. Journal of Health Psychology, 1-11. Published online August 25, 2016. doi: 10.1177/1359105316664139
Post-exertional malaise is a cardinal symptom of myalgic encephalomyelitis and chronic fatigue syndrome. There are two differing focuses when defining post-exertional malaise: a generalized, full-body fatigue and a muscle-specific fatigue. This study aimed to discern whether post-exertional malaise is a unified construct or whether it is composed of two smaller constructs, muscle fatigue and generalized fatigue. An exploratory factor analysis was conducted on several symptoms that assess post-exertional malaise. The results suggest that post-exertional malaise is composed of two empirically different experiences, one for generalized fatigue and one for muscle-specific fatigue.


McManimen, S. L., & Jason, L. A. (2017). Post-exertional malaise in patients with ME and CFS with comorbid Fibromyalgia. SRL Neurology & Neurosurgery, 3, 22-27. PMCID: PMC5464757
Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS) share some similar symptoms with Fibromyalgia (FM). Prior research has found increased illness severity when patients have FM that is comorbid with ME and CFS. For example, Post- Exertional Malaise (PEM) has been shown to be more severe in those with comorbid FM. However, PEM can be separated into two factors, Muscle and General PEM. It is unknown if the more severe PEM findings in comorbid FM are due to the Muscle or General PEM factor. The purpose of this study was to determine if the PEM differences seen between patients with and without comorbid FM exist for the Muscle or General PEM factors. An international convenience sample was collected via an online questionnaire. The questionnaire assessed the frequency and severity of several PEM-related symptoms. Additionally, participants provided information regarding the course and characteristics of their illness. Participants that indicated a comorbid diagnosis of FM displayed significantly more frequent and severe PEM symptoms in the Muscle and General PEM factors. The FM group also indicated significantly worse physical functioning compared to the group without comorbid FM. The secondary diagnosis of FM in addition to ME and CFS appears to amplify the PEM symptomatology and worsen patients’ physical functioning. The findings of this study have notable implications on the inclusion of patients with comorbid FM in ME and CFS research studies.

Jason, L.A., Ohanian, D., Brown, A., Sunnquist, M., McManimen, S., Klebek, L., Fox, P., & Sorenson, M. (2017). Differentiating Multiple Sclerosis from Myalgic Encephalomyelitis and Chronic Fatigue Syndrome. Insights in Biomedicine, 2, No. 2: 11. doi: 10.21767/2572-5610.100011
Multiple Sclerosis (MS), Myalgic Encephalomyelitis (ME), and Chronic Fatigue syndrome are debilitating chronic illnesses, with some overlapping symptoms. However, few studies have compared and contrasted symptom and disability profiles for these illnesses for the purpose of further differentiating them. The current study was an online self-report survey that compared symptoms from a sample of individuals with MS (N = 120) with a sample of individuals with ME or CFS (N = 269). Respondents completed the self-report DePaul Symptom Questionnaire. Those individuals with ME or CFS reported significantly more functional limitations and significantly more severe symptoms (for fatigue, post-exertional malaise items, sleep items, pain items, neurocognitive items, autonomic items, neuroendocrine items, and immune items) than those with MS. The implications of these findings are discussed.


Jason, L.A., Evans, M., So, S., Scott, J., & Brown, A. (2015). Problems in defining post-exertional malaise. Journal of Prevention and Intervention in the Community, 43(1), 20-31. doi: 10.1080/10852352.2014.973239
PMCID: PMC4295644
Post-Exertional Malaise (PEM) is a cardinal symptom of the illnesses referred to as Myalgic Encephalomyelitis (ME), Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), and chronic fatigue syndrome (CFS). PEM is reported to occur in many of these patients, and with several criteria (e.g., ME and ME/CFS), this symptom is mandatory (Carruthers et al., 2003, 2011). In the present study, 32 participants diagnosed with CFS (Fukuda et al., 1994) were examined on their responses to self-report items that were developed to capture the characteristics and patterns of PEM. As shown in the results, the slight differences in wording for various items may affect whether one is determined to have PEM according to currently used self-report criteria to assess CFS. Better understanding of how this symptom is assessed might help improve the diagnostic reliability and validity of ME, ME/CFS, and CFS.


Jason, L.A., & Evans, M. (2012). To PEM or not to PEM? That is the question for case definition. Research 1st Retrieved May 2, 2012 at: http://www.research1st.com/2012/04/27/pem-case-def/
The criteria for defining cases is an important topic in research and medicine. For chronic fatigue syndrome, it has been a vexing topic whether one considers CFS to be a new condition identified with the 1988 case definition (Holmes, et al.) or a new (if unwanted) name for a condition that has existed for decades, if not centuries, by other names. Here we will examine the cluster of symptoms known as post-exertional malaise (PEM) and its importance in defining the condition. PEM is also known as post-exertional relapse. It refers to the aggravation of various symptoms following even modest physical or mental exertion.


Jason, L.A., Sunnquist, M., Brown, A., Furst, J., Cid, M., Farietta, J., Kot, B., Bloomer, C., Nicholson, L., Williams, Y., Jantke, R., Newton, J.L., & Strand, E.B. (2015). Factor analysis of the DePaul Symptom Questionnaire: Identifying core domains. Journal of Neurology and Neurobiology, 1(4). doi http://dx.doi. org/10.16966/2379-7150.114 PMCID: PMC4830389
The present study attempted to identify critical symptom domains of individuals with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Using patient and control samples collected in the United States, Great Britain, and Norway, exploratory factor analysis (EFA) was used to establish the underlying factor structure of ME and CFS symptoms. The EFA suggested a four-factor solution: post-exertional malaise, cognitive dysfunction, sleep difficulties, and a combined factor consisting of neuroendocrine, autonomic, and immune dysfunction symptoms. The use of empirical methods could help better understand the fundamental symptom domains of this illness.


Jason, L.A., Jessen, T., Porter, N., Boulton, A., Njoku, M.G., & Friedberg, F. (2009). Examining types of fatigue among individuals with ME/CFS. Disability Studies Quarterly, 29, (available at http://www.dsq-sds.org/article/view/938/1113).

Severe, persisting fatigue is a prominent symptom of Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), but individuals with this illness frequently report the occurrence of unique fatigue states that might be different from conventional symptoms of fatigue. The present study attempted to assess a comprehensive set of fatigue symptoms that have been commonly reported among patients with ME/CFS. A 22-item fatigue questionnaire was developed and administered to 130 persons diagnosed with ME/CFS and 251 controls. Adequate scale reliability was found. Factor analyses revealed a five-factor structure for participants with ME/CFS but only a one factor solution for the control group. The new scale was also contrasted with other more traditional scales developed to measure fatigue. Findings suggest that individuals with ME/CFS experience different types of fatigue than what are reported in the general populations.

 

[susanna]

Thank you, Leonard. Like Trish, I have a big problem with use of the 'fatigue' word especially as a habit is creeping in in various papers diluting PEM to post -exertional 'fatigue'.
My other concern is the use of frequency of symptoms in PEM. They do not occur in terms of frequency but as a result of activity. I cannot answer this question with any accuracy. As others have stated, they might hardly ever get PEM because they confine their activities appropriately, but if they exceeded their level frequently they might get PEM quite often. So, it would be more accurate to ask what level of activity triggers off PEM.

 

[susanna]

Defining PEM is easy but measuring it subjectively and its frequency can be meaningless and fraught with misinterpretation. The NAM description seems accurate and it and the IOM description don't get bogged down in symptom lists. The key to a PEM definition in my opinion is its overall characteristics and the potential triggers. The NAM and IOM fail to identify all the triggers...= that exacerbate the symptoms e.g. major intolerances to chemicals, foods, light noise, vibration, sensory overload etc these triggers can be much harder to identify and control than physical/cognitive exertion and lead to the view that PEM is random and/or unavoidable. Jason, Klimas etc all state that the more severe patients often have less symptoms. Obviously not because they are healthier but because they have learnt to avoid PEM triggers severe end of the spectrum are missing from ALL existing diagnostic criteria so far. PEM shows up on heart rate traces it can be objectively seen and measured by patients. A descriptor for PEM is all we have right now but maybe the real work needs to be done on validating/measuring/comparing the changes in the HR traces of people in and out of PEM? Maybe bedridden/housebound people are the best to use or maybe the bedridden/housebound people are different but certainly in this group the orthostatic variation in HR is markedly greater on a PEM day as is the heart rate variation (spikiness of the HR trace) throughout the day. The NICE Guideline may need to suggest things that might help/patterns that some patients have reported that others may use. The Royal College boffins will turn to the published papers by their mates and meta analyse them yet again ignoring that garbage in = garbage our. We need to be creative about how we want our perspective to be included when the patient story has been ignored and we don't have research to back us. Our experiences can still be included under headings such as patient findings yet to be tested by research....expansion of the heart rate pacing section of NICE.

May be we can avoid the problem of fewer symptoms because excessive activity is avoided, by asking how much a patient can do before they get PEM. ie, a modified SF-36 type scale. This would show the amount of activity limitation they experience in order to limit symptoms.

 

[susanna]

Thanks for looking into this @Simon M. It's lot of info so I will have to come back and re-read a few times to get my head around it.

First glance: I share your concerns. I am very much opposed to questionnaire that require "judgement" I behalf of the researcher. These have been used to our detriment in the UK IMO.

I agree that most patients who have been ill for any length of time will be pacing (even if they don't recognize the term or its not done consciously) to avoid PEM. The questionnaire needs to get to the bottom of that.

I agree. The scale should be able to show, 'these patients don't get much PEM, but how much activity do they sacrifice for this?

 

[ahimsa]

Defining PEM is easy...

Not for me. I have a really hard time defining PEM with words.

A lot of the detailed PEM descriptions post on this thread are very hard for me to read and absorb so I hope no one here thinks I'm ignoring posts on this thread. I did read this thread and tried to understand what has been posted so far. I think this might be duplicating some of what has been posted already, but some of it may be new, so I'm posting it.

I can recognize PEM when I get it. And I can give a general description. But I don't think I could ever come up with a definition, a clear list of symptoms that would fit all ME patients (or even majority of patients).

Mostly that's on me - brain fog! But I also think creating a PEM definition is difficult thing for anyone to do.

I don't know if this helps at all with creating a definition or questionnaire but for me this point is important. For ME patients who used to do exercise the PEM experience feels completely different from the normal soreness or achiness of overdoing it when your body is normal.

So many doctors seem to think PEM is an extreme version of normal exhaustion after over-exertion. But it's not. At least, not for me.

For me, PEM is a different kind of feeling. As I posted on another thread once, I never got symptoms like dizziness, nausea, fasciculations (tiny muscle twitches), headache, breathlessness (not during the exertion, the next day or two, after the PEM hits), etc. Even after doing serious exertion, such as climbing to the summit of Mount Hood, these kind of weird symptoms never hit me.

And these days I never get any normal muscle soreness (I actually kind of miss that feeling). When I do get muscle aching it's a different sort of ache, an ache that feels more like a tetanus shot or a typhoid shot. But that kind of weird muscle ache is different from the normal kind of soreness/ache that happened to me after increasing the difficulty in my weight lifting routine, or hiking a longer/steeper route, or anything like that.

Anyone who has lifted weights and gotten a shot can easily agree that those are two different kinds of muscle pain, right? (I hope? Maybe it's just me?)

Just some rambling thoughts in case they are helpful.

 

[Sean]

Jane Colby suggests "Post Exertional Deterioration" instead of "malaise".

My pick.

 

[Inara]

For ME patients who used to do exercise the PEM experience feels completely different from the normal soreness or achiness of overdoing it when your body is normal.

So many doctors seem to think PEM is an extreme version of normal exhaustion after over-exertion. But it's not. At least, not for me.

That's something I can confirm. Of course, when training you overdo it on a regular basis. Afterwards, I felt exhausted but happy. It was a satisfying exhaustion. I didn't feel energy-less though, I felt alive. I had muscle achiness and did easy training after a hard unit with no problems at all; it felt good.

Today, if I overdo it, I feel like crap; no happiness or liveliness at all, the absolute contrary. I feel like there's no energy. Cognitive symptoms increase, I might have headaches, too. The sleep is worse. Even the muscle ache feels different - it's more intensive; the muscles feel stale and weak, and even easy usage wouldn't be good. I might have joint pain.
It's very hard to explain.

 

[Invisible Woman]

That's something I can confirm.

Yep. Me too. I used to exercise regularly, it was a great way of destressing from my job. If I stopped for a few weeks and had to restart it was very hard to get back in to it, stiff, achy muscles but it was NOTHING like PEM. PEM is like nothing I experienced before I became ill.

In fact when I was a schoolgirl we used to do 24 hour sports marathons to raise cash for school trips or charity etc. You'd play for 45 mins and then have 45 mins off throughout. Then you get to 2 or 3 am and there was no shifting some lazy beggars out of their sleeping bags. Being one of the fitter people with quite good stamina, I was one of the ones who would play on. Even a 24 hour marathon wouldn't trigger the kind of symptoms I get with PEM.

Post exertional deterioration - yeah. That's the best name for it yet.

 

[Leonard Jason]

I would like to provide some more information to the larger community about recent work we have done on the DSQ. Over the last 2 years, our group has published several articles on PEM, and we had collected data from 704 patients in an international convenience sample of adult patients self-identifying as having ME or CFS. Our results suggest that post-exertional malaise is composed of two empirically different experiences, one for generalized fatigue and one for muscle-specific fatigue in these findings are in the following publication (you can find this article on ResearhGate under my name): McManimen, S. L., Sunnquist, M. L., & Jason, L. A. (in press). Deconstructing post-exertional malaise: An exploratory factor analysis. Journal of Health Psychology, 1-11. Published online August 25, 2016. doi: 10.1177/1359105316664139

In data that is still not published, we also found that the item that was liked by the highest percentage of patients (89%) was from the Ramsay criteria (Prolonged worsening of symptoms after physical activity; and two Ramsay items were: Muscle fatigability after minor exertion, and muscle weakness after minor exertion). In addition, the second highest rating (88%) was for symptoms worsen with exertion, an item from the ME-ICC. In part, because of these findings, our second version of the DSQ that we have been using over the past year has included the following three PEM items: Muscle fatigue after mild physical activity, worsening of symptoms after mild physical activity, and worsening of symptoms after mild mental activity.

As is evident, our first version of the DSQ was modified in this PEM area and in other areas based on patient input, and we are grateful for constantly trying to improve our instruments based on feedback from the larger patient community. We are now working on projects to validate the PEM score with a number of physiological measures.

Our group has tried to operationalize the criteria that the CDE has proposed for PEM, and we needed 30 questions to measure this construct. The Questionnaire that we developed is at the end of this email. And as is evident, specifying domains of importance is only a first step, and it is critical to designate explicit ways to measure the symptom and then how to score it for whether it meets the criterion being assessed.


Here's the draft definition of PEM that a Common Date Elements group is now working on.

PEM is defined as 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. Symptoms exacerbated can include physical fatigue, cognitive fatigue, problems thinking (e.g. slowed information processing speed, memory, concentration), unrefreshing sleep, muscle pain, joint pain, headaches, weakness/instability, light-headedness, flu-like symptoms, sore throat, nausea, and other symptoms. Study participants can experience new or non-typical symptoms as well as exacerbation of their more typical symptoms.

2. Loss of stamina and/or functional capacity

3. An onset that can be immediate or delayed after the exertional stimulus by hours or days but the exact timing is not well understood.

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. For some study participants, even basic activities of daily living like toileting, bathing, dressing, communicating, and reading can trigger PEM.

Some other precipitants of PEM that have been identified include positional changes and emotional stress. In some instances, the specific precipitant cannot be identified. The threshold for a precipitant to trigger PEM can vary between individuals as well as within the same individual, at different times during their illness.

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Here is what would need to occur to operationalize these criteria, and it is still a bit uncertain what scores would be needed to designate that a person had PEM. Therefore data would need to be collected to answer this important question.

Post Exertional Malaise Questionnaire


1.Do you experience an abnormal response to minimal amounts of physical exertion?

Yes____ No_____


2. Do you experience an abnormal response to minimal amounts of cognitive exertion?

Yes____ No_____


If you experience this abnormal response to physical or cognitive exertion, which symptoms below are made worse:


3.Physical fatigue: Yes____ No_____


4.Cognitive fatigue: Yes____ No_____


5.Problems thinking (e.g. slowed information processing speed, memory, concentration):

Yes____ No_____


6.Unrefreshing sleep: Yes____ No_____


7.Muscle pain: Yes____ No_____


8.Joint pain: Yes____ No_____


9.Headaches: Yes____ No_____


10.Weakness/instability: Yes____ No_____


11.Light-headedness: Yes____ No_____


12.Flu-like symptoms: Yes____ No_____


13.Sore throats: Yes____ No_____


14.Nausea: Yes____ No_____

15.Loss of stamina and/or functional capacity: Yes____ No_____

16.Other symptoms please specify: ____________________

17.The onset of your abnormal response to physical or cognitive exertion is immediate after the exertion: Yes____ No_____

18.The onset of your abnormal response to physical or cognitive exertion is delayed after the exertion: Yes____ No_____

19. If your onset is delayed, your abnormal response to physical or cognitive exertion is delayed after the exertion by (check one box below):

 1 hour or less

 2-3 Hrs

 4-10 Hrs

 11-13 Hrs

 14-23 Hrs

 More than 24 Hrs (Please specify__________)



20.Your prolonged, unpredictable recovery period from abnormal response to physical or cognitive exertion may last days, weeks, or even months.

Yes____ No_____


21. If yes, your prolonged, unpredictable recovery period that may last (check one box below):

 Within 24 hours

 Over 1 week

 Over 1 month

 Over 2-6 months

 Over 7-12 months

 Over 1-2 years

22.The severity and duration of your abnormal response to physical or cognitive exertion symptoms is often out-of-proportion to the type of the exertion. Yes____ No_____


23.The severity and duration of your abnormal response to physical or cognitive exertion symptoms is often out-of-proportion to the intensity of the exertion. Yes____ No_____


24.The severity and duration of your abnormal response to physical or cognitive exertion symptoms is often out-of-proportion to the frequency of the exertion. Yes____ No_____


25.The severity and duration of your abnormal response to physical or cognitive exertion symptoms is often out-of-proportion to the duration of the exertion. Yes____ No_____


26. Do basic activities of daily living like toileting, bathing, dressing, communicating, and reading trigger your abnormal response to physical or cognitive exertion? Yes____ No_____


27. Precipitants of your abnormal response to physical or cognitive exertion include positional changes (e.g., your body position is shifted from the standing to lying down). Yes____ No_____


28. Precipitants of your abnormal response to physical or cognitive exertion include emotional stress. Yes____ No_____


29.In some instances, the specific precipitant of your abnormal response to physical or cognitive exertion cannot be identified. Yes____ No_____


30. The threshold for a precipitant to trigger your abnormal response to physical or cognitive exertion varies as it occurs at different times during your illness. Yes____ No_____

 

[Invisible Woman]

Some other precipitants of PEM that have been identified include positional changes and emotional stress. In some instances, the specific precipitant cannot be identified. The threshold for a precipitant to trigger PEM can vary between individuals as well as within the same individual, at different times d

Enviromental factors: heat, sensory stimulation (noise, lots of fast moving visual info such as travelling in a car) are also common triggers. In my own case environmental factors are far more likely to trigger PEM than emotional one, but that may not be true for others.