Is the 'fatigue'/'tiredness' experienced by pwME a form of Dynapenia?

I was playing around with a medical dictionary to try and come up with an alternative for 'fatigue' which is more or less the common denominator in all ME/CFS diagnostic criteria.

Note: I was not trying to invent a new name for the illness!

Anyway, having come up with a couple I thought I'd better do a search and see if they were currently used.
Dynapenia came up. From the dictionary I used it means 'energy deficiency'.

It is a relatively new term being used in research related to aging.

Wikipedia has an entry (most of it is waffle), but the biology bit is interesting:

"Studies involving the dissection of cadavers have uncovered a 43% decrease in the cell body size of neurons found in the premotor cortex compared to those of younger adults.[25] New studies have recently verified this finding in living subjects using high resolution magnetic resonance imaging (MRI).

Recent evidence suggests that aging is also related to the loss of myelinated nerve fiber length and the mass of white matter, with individuals losing approximately 45% of total nerve fiber length as they age.[27] [28] These changes that develop through the aging process affect the connectivity of the cortex within itself as well as its connectivity to the rest of the central nervous system.

Another potential contributor to dynapenia is a disruption of the process that converts electrical signal given for muscular activation into an actual contraction. Particularly, impairments in the release of calcium (Ca2+) from the sarcoplasmic reticulum have been suggested to explain why decreased muscle quality is so prevalent in older adults.

It has also been suggested that nutritional factors may contribute to the onset of dynapenia. It has been proposed that low levels of Vitamin E,[41] [42][43]carotenoids,[41][44] and selenium[45] [46] are associated with lower levels of muscle strength.

The activity of Vitamin D receptors on muscle has been found to decrease with aging. These receptors initiate the nuclear response leading to De novo synthesis of proteins.[47] However, the results of multiple studies on the relation between Vitamin D and muscle strength have been highly controversial, making the effect of Vitamin D on muscle strength in need of further investigation."

The researchers ( who initially proposed use of dynapenia in 2008) update in 2012;
"There is evidence to suggest that dynapenia is, to some extent, attributable to neurologic mechanisms."
"Interestingly, over the past couple of years, there have been several reports suggesting a link between muscle weakness and cognitive decline"

https://academic.oup.com/biomedgerontology/article/67A/1/28/583360

there is a lot of scientific stuff which maybe someone else would like to look at.

The actual condition as described may not be applicable, but the 'effect' sounds much closer to what I for one experience as opposed to 'fatigue'.

 

yes I read that.

"In 2008 we proposed the term dynapenia to define the age-related loss of muscle strength and power [20]. Dyna refers to “power, strength, or force” and penia refers to “poverty.” We should note that Morley et al. [21] recently used the term kratopenia to characterize the “loss of force” and dynapenia to characterize the “loss of power.”

In the context of this review, we refer to dynapenia within the context of our original definition, which encompasses the broader aspects of skeletal muscle force performance and includes strength (i.e., maximal voluntary force) and/or mechanical power (a product of force times velocity), which are commonly measured using dynamometry equipment (e.g., isometric strength, isokinetic power, etc.)."

As I mentioned the use of the term 'dynapenia' seems to be in development.

I would suggest the use of the word 'fatiguability' is only because there is currently no other way to describe what is going on.

 

A couple of weeks ago, I was trying to come up with some alternative name for ME/CFS that did not involve "fatigue" or "exhaustion." The problem with those words is that they are predicated on "exertion." Although people with ME worsen with exertion, my experience with ME is one of being in a state of low energy most of the time, not just following exertion.

I thought I'd hit on something when I came across the Greek word "anergy," which (according to Webster's) means "a pathological lack of energy." Perhaps "Chronic Systemic Anergy," or something like that...

I found that, in Immunology, "anergy" specifically refers to the immune system's lack of response to an antigen. Still, I didn't see why the same term couldn't be used in a more general context.

Unfortunately, I then discovered that the related term "anergia" has been appropriated by psychiatry / psychology. When you look up "anergia," its primary medical use seems to be defined as "an abnormal lack of energy" as a symptom of depression and schizophrenia.

It was at that point that I decided to set the idea aside.

 

Yes, from observing my wife I would say she has quite a good level of physical fitness, but simply lacks the energy supply needed to meet the demand. In my mind I model it as being a fit person, but with a tap controlling their energy supply. Turn the tap down so the flow of fuel is restricted, and no matter how fit you are, you will be going nowhere fast.

To me a relevant terminology would be "energy depletion".

 

That's not what I was trying to do but it was annoying to find the word had already been nabbed.

I was trying to come up with something to describe the symptom in ME/CFS that is called fatigue but which most people say is much more than 'just fatigue'. Just to clarify, I am also not referring to PEM.

Apart from the name 'dynapenia', which I think is apt (without the way it has been defined relating to aging), I thought it interesting that the researchers thought that it was necessary to create a separate definition from 'sarcopenia':

"Sarcopenia is the degenerative loss of skeletal muscle mass (0.5–1% loss per year after the age of 50), quality, and strength associated with aging."

to try and define the loss of muscle strength separately rather than combining the two
(although I think it would have been better if they had gone for power rather than strength).

So what I'm trying to say is, whatever the underlying mechanism is, the resulting symptom (ie greatly impaired ability to walk, move about, carry things etc ) although not necessarily constant in ME/CFS, is akin to dynapenia.

Like saying a headache is 'migraine like' although it is not a migraine.

hope I've explained it better although wrong time of day for me to be trying to think

 

Hmm, I describe my current, crashed state as being totally enervated:

verb (used with object), en·er·vat·ed,en·er·vat·ing.

1. to deprive of force or strength; destroy the vigor of; weaken.

adjective (ɪˈnɜːvɪt)

1. deprived of strength or vitality; weakened

It feels accurate.

 

Not sure. I think stamina is another of those words that can have a lot of woolly meanings.

 

The word Exhaustion pretty much sums it up for me.
I never use the word fatigue to describe this illness, for me it sounds too passive, compared to the strength of symptoms.

 

@Peter Trewhitt posted this on another thread, and it sums up what I have been trying to say:

"...ME is qualitively different to 'being tired', to help understand there is a unique and abnormal biological process involved even though we do not fully understand that process."

So based on that I've come up with a word that isn't used for anything else (as far as google is concerned anyway):

Dysdynamosis which means bad(disfunctional) energy process.

 

I would describe mine as autonomic dysfunction fatigue, it feels like a cerebral blood flow problem. It's relieved after lying down for a short time.

 

I am all for names that people in general don't understand, as it means they have to ask what the word means. So many terms associated with ME seem to the lay (or even some professional) audience to have an obvious meaning which in practice results in misunderstanding.

The obvious example is ME versus CFS. In general no one, expect students of medical Latin, understands what ME means, but everyone thinks they know what CFS means. The use of CFS for example has allowed the BPS crew much freer range to highjack and perhaps even deliberately misunderstand the syndrome.

Researchers, doctors and patients are seeking to develop a technical language to describe our syndrome and its symptoms, in general we are using a 'jargon' developed from everyday vernacular terms that have confusingly different albeit related day to day meanings.

 

I didn't think that at all @Trish. I thought, Broken Dynamo. As in the electricity generator.

Our minds all jump differently! I think it's brilliant @Sly Saint I'll start using it, for sure

On my smug Dr brother, first up.

 

There’s also the brain and sensory fatigue and the chicken and egg question.

I’ve been pretty bad recently and once again feel very much like I have a hole in the base of my brain /top of neck and my brain just feels like it’s shut down , not signalling. I also as I rest get the feeling like you do in a dead leg as it comes to life, it feels like circulation is improving/neurons firing.

I know there’s split views on severe ME , is it normal ME pushed to extremes where the fundamental signs become clearer or is it additional factors caused by the common denominator stuff. I certainly think there’s brain signalling /low activity issues in me and the recent brain stem research was extremely interesting to me. On its own that could cause fatigue and movement being exhausting I think and some think brain dysfunction is the culprit . To what extent all people with ME have this or if it actually starts off primarily as a cellular energy disorder , perhaps chiefly experienced as peripheral muscle fatigue in the mild which then leads to more debilitating brain issues as things advance remains to be revealed.

Trying to sum up a wide ranging experience to replace the inadeqte fatigue terminology is hard. I don’t mind talk like “low energy state” , I personally don’t like reduction to muscle fatigue but some don’t feel low energy until they exert.

 

Other options:

• dysenergy
• anenergy
• hypoenergy
• avigour
• avitality

None of them is entirely satisfactory.

 

I do not know if my experience of ME is the same as anyone else's. Recently, I have been exploring within myself to try to find exactly what it is I feel but I do not have the vocabulary. One realisation is that we all try to fit our experience into the terms the "experts" impose. People say they are fatigued but when you read how other illnesses experience fatigue it does not seem to reflect what we talk about here.

One thing that is easy to describe is what I call fatiguability. How much I can do varies immensely (though never very much) then I suddenly stop, I could not move or finish the action if I was on fire. A few minutes or even seconds later, I can start going again but I know I have to rest properly so I finish the action, cleaning my teeth, picking up a book or even saying a sentence. Then I lie down or sit in my wheelchair with my eyes close and try to stop all action for a while if I am outside. I have no idea if anyone else with ME reacts like this. Something is used up and then it starts to come back. The Workwell results where you can run out of ATP seem relevant but who knows?

Maybe more like other people is that I can't do very much. I have a certain amount of capability for the day and when it is done, that's it. It sounds like fatigue, but when I was first diabetic I felt as if gravity had increased and that actually was fatigue, different from my usual.

This, of course, is my background capabilities and doesn't take into account the way, pain, paralysis, eye and vision problems, vertigo, so on the list is endless interferes with my living to make it so far from normal.

I wish we had the proper words or at least an idea of what is wrong like in MS and RA. Till then I will probably carry on telling my family that I feel "a little bit tired" when I can't move, like so many of us do, sigh.