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Long-term neuromuscular consequences of SARS-Cov-2 and their similarities with ME/CFS: results of the retrospective CoLGEM study, 2022, Retornaz et al

Discussion in 'ME/CFS research' started by Andy, Sep 25, 2022.

  1. Andy

    Andy Committee Member

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    Location:
    Hampshire, UK
    Abstract

    Background
    Patients with long-COVID often complain of continuous fatigue, myalgia, sleep problems, cognitive dysfunction, and post-exertional malaise. No data are available on EMG recording of evoked myopotentials (M-waves) or exercise-induced alterations in long-COVID patients, providing evidence of muscle membrane fatigue. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develops in more than half of patients after an infectious disease, particularly viral diseases. A large proportion (around 70%) of these patients have neuromuscular disorders with M-wave alterations during and after exercise. Our hypothesis was that M-wave alterations would be also found in long-COVID patients, in association with neuromuscular symptoms, similar to ME/CFS.

    Methods
    This retrospective observational ColGEM (Covid LonG Encéphalomyelite Myalgique) study compared 59 patients with long-COVID and 55 ME/CFS patients with a history of severe infection who presented before the COVID pandemic. All of these patients underwent the same protocol consisting of a questionnaire focusing on neural and neuromuscular disorders and M-wave recording in the rectus femoris muscle before, during, and 10 min after a progressive cycling exercise. Maximal handgrip strength (MHGS) and maximal exercise power were also measured. The frequency of symptoms and magnitude of M-wave changes in the two groups were compared using non-parametric and parametric tests.

    Results
    The frequency of fatigue, myalgia, sleep problems, cognitive dysfunction, and post-exertional malaise as well as the magnitude of exercise-induced M-wave alterations were the same in the two groups. By contrast, digestive problems were less present in long-COVID. M-wave alterations were greater in ME/CFS patients as in those with long-COVID when the highest muscle strength and highest exercise performance were measured.

    Conclusions
    These high clinical and biological similarities between long-COVID and ME/CFS support the hypothesis that SARS-Cov-2 infection can cause ME/CFS symptoms.

    Open access, https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03638-7
     
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  2. Hutan

    Hutan Moderator Staff Member

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    Location:
    Aotearoa New Zealand
    14 Jammes Y, Steinberg JG, Delliaux S. Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins. J Intern Med. 2012;272:74–84.

    15 Jammes Y, Steinberg JG, Mambrini O, Brégeon F, Delliaux S. Chronic fatigue syndrome: assessment of increased oxidative stress and altered muscle excitability in response to incremental exercise. J Intern Med. 2005;257:299–310.

    16 Jammes Y, Adjriou N, Kipson N, Criado C, Charpin C, Rebaudet S, et al. Altered muscle membrane potential and redox status differentiates two subgroups of patients with chronic fatigue syndrome. J Transl Med. 2020;18:173.
    Science for ME discussion, with an explanation of M-waves from @Snow Leopard
     
    Last edited: Sep 25, 2022
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  3. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Location:
    Australia
    See also:
    The Hoffmann Reflex: Methodologic Considerations and Applications for Use in Sports Medicine and Athletic Training Research
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC522151/
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC522151/figure/F1/



    (type 1a sensory fibres are part of muscle spindles which measure muscle stretch - these spindles are effectively in parallel with the main alpha muscle fibres and note that they have their own separate drive from the brain (gamma motor neurons), the purpose of which is to keep the muscle spindles taught)

     
    Last edited: Sep 27, 2022
    ukxmrv and Hutan like this.
  4. Hutan

    Hutan Moderator Staff Member

    Messages:
    26,529
    Location:
    Aotearoa New Zealand
    This might be useful too for those coming to this cold:
    https://loonylabs.org/2020/03/03/the-f-wave/

    I found the diagram useful for getting to grips with which way the motor fibres and afferent fibres go, and what is going on with these waves. Afferent fibres go towards the central nervous system. Motor fibres go from the central nervous system towards the muscles.

    Screen Shot 2022-09-28 at 3.37.33 pm.png
     
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