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Investigation into the Pathophysiology & the Objective Neurophysiological Measurement of Cancer-Related Fatigue (ME/CFS control group),2020, O'Higgins

Discussion in 'BioMedical ME/CFS Research' started by Dolphin, May 24, 2020 at 2:02 AM.

  1. Dolphin

    Dolphin Senior Member (Voting Rights)

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    This study used ME/CFS patients as a control group. I haven't read it yet.

    Free full text: <http://www.tara.tcd.ie/handle/2262/92573>

     
  2. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Hypotheses of fatigue are discussed, though managed to overlook the endothelial dysfunction hypothesis - an aspect that could be shared between CRF and CFS. The usual (questionable) demarcation between central and peripheral fatigue that ignores any couplings between metabolism and regulation of motor nerve sensitivity.


    Also the common myth of slow twitch vs fast twitch muscle fibres - when twitch speed of muscle fibres actually has a Gaussian distribution, so "slow" and "fast" twitch fibres are just the tail ends of the distribution.

    The discussion of contractile properties seemed to claim that the "central activation failure" is due to lack of central drive, when the study cited for CFS found the opposite - increased EEG activity in the theta band and increased motor activity-related cortical potential suggesting increased concentration/voluntary motor effort.
    (example of increased theta power: https://www.tandfonline.com/doi/abs/10.1080/00222895.2019.1635983?journalCode=vjmb20)

    Cited CFS study: https://pubmed.ncbi.nlm.nih.gov/15351380/ (Siemionow et al. 2004)

    Nonetheless, the studies in the thesis provide some interesting data on both EMG and EEG differences during sustained contractions at 30% of MVC, with 10 seconds of rest in-between, until force dropped below 27% of MVC. Do note that they were not age/sex matched. Both CRF and CFS groups had greater statistical differences in normalised EMG amplitudes compared to healthy controls, despite lower absolute force outputs.
     
    Last edited: May 24, 2020 at 6:20 AM
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  3. rvallee

    rvallee Senior Member (Voting Rights)

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    This is the failure right here. It mixes motivation with fatigue and various manifestations of what could be fatigue but is unclear are the same thing. Words have meaning. Use those words with their proper meaning. This is something we learn in kindergarten and even before. If you call a cookie a brush and expect people to give you cookies as you insist on calling it a brush your mommy and/or teacher is going to take you aside and explain to you why it's important to use the proper words for their intended meaning and nothing else (poetic license aside anyway).

    Basically in medicine fatigue is a word used to describe any of a number of things, from motivation to sleepiness to stamina and many other different and unrelated things. This is why we've seen nothing but failure. You cannot do formal science with this much confusion over basic vocabulary. When the same word can mean about a half-dozen different things there will be nothing but confusion. Especially as those alternative meanings have their word in both common and clinical use. Sleepiness is sleepiness whether you are a child or a sleep specialist. Everyone understands what it means. To use fatigue to mean the same thing is just complete nonsense. Yes, everyone gets tired. No, you're not clever for bringing this unrelated thing to a discussion over a different thing.

    Until medicine sorts out this deliberate mess I don't think any progress can be made. The foundation of science is to be able to tell things apart from other things. This is how it all begins. When you fail at the very first step you will do nothing but wander aimlessly. Because while you wander into the vast wilderlands of imaginationland people are not doing well at all as a result.

    Do better. Please. For the literal sake of millions do a lot better than this.
     
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  4. Sean

    Sean Senior Member (Voting Rights)

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    Interesting. :geek:
     
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  5. Trish

    Trish Moderator Staff Member

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    I have only read the abstract, but it sounds to me as if it might be a useful way of objectively measuring muscle fatiguability in ME, even if it doesn't explain the mechanisms of that fatiguability.

    That seems a useful step forward to me. I'd rather squeeze a hand held dynamometer and have my EEG and EMG measured while doing it than fill in the Chalder Fatigue Questionnaire!
     
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  6. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    That is not what was shown though. This is not a specific biomarker. It is difficult to control for effort (and difficult to directly examine the coupling between peripheral and central fatigue), so it is easy for researchers, including the authors of this thesis to simply conclude that the issue is of "centrally mediated disorder" and not delve any deeper.

    Oh and statements like:
    for good measure.
     
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  7. Trish

    Trish Moderator Staff Member

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    Thanks @Snow Leopard. I do understand it's not specific enough to be a biomarker. I was thinking more of it's possible use a before and after outcome measure for treatment trials, to be used alongside other objective measures and instead of fatigue questionnaires like CFQ. Less exhausting than the 6 minute walk or the step test or CPET perhaps.
     
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  8. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    I was thinking which would I rather do, and the answer is none of them, but I guess I'd rather do the 6MWT, followed by this test, followed by the step test followed by the CPET in last place if forced to make a choice.

    The protocol:
    Also, on second reading, I note the curious omission of the participant reported acceptability in the second (CRF/CFS) study. I don't know why the thesis was accepted without this being reported.
     
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  9. spinoza577

    spinoza577 Senior Member (Voting Rights)

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    But it´s doubled easy. Even if there is a centrally mediated disorder indeed, well hinted or maybe even confirmed (if possible) by any improved method your are requesting, it does not say that this centrally mediated disorder is driven by any proportion that can be influenced psychologically.

    They failed already on a logical level, regardless of how this empirical investigation has come out.

    Nerves should be able to fail on a very technical level, maybe even for simple reasons. Such principal possibility is not difficult to see. Their twitching doesn´t provide what they then convey.

    Their negative finding, and any negative finding, does not add evidence to these "suggested proves".
     
    Last edited: May 25, 2020 at 9:36 PM
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  10. alex3619

    alex3619 Senior Member (Voting Rights)

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    My current hypothetical stand is the distinction may be arbitrary. It may just be putting a different label to the same underlying physiology.
     
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  11. alex3619

    alex3619 Senior Member (Voting Rights)

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    I am hoping that the nanoneedle, or other blood test, might decrease the need for exercise tests. Force our blood cells to exert and see their failure ... that is enough.
     

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