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Functional and microstructural brain abnormalities, fatigue, and cognitive dysfunction after mild COVID-19, 2021, Silva et al

Discussion in 'Epidemics (including Covid-19)' started by rvallee, Mar 25, 2021.

  1. rvallee

    rvallee Senior Member (Voting Rights)

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    (Paragraphed for clarity)

    Although post-acute cognitive dysfunction and neuroimaging abnormalities have been reported after hospital discharge in patients recovered from COVID-19, little is known about persistent, long-term alterations in people without hospitalization.

    We conducted a cross-sectional study of 87 non-hospitalized recovered individuals 54 days after the laboratory confirmation of COVID-19. We performed structured interviews, neurological examination, 3T-MRI scans with diffusion tensor images (DTI) and functional resting-state images (fMRI).

    Also, we investigated fatigue, anxiety, depression, somnolence, language, memory, and cognitive flexibility, using validated instruments. Individuals self-reported a high frequency of headache (40%) and memory difficulties (33%). The quantitative analyses confirmed symptoms of fatigue (68%), excessive somnolence (35%), anxiety (29%), impaired cognitive flexibility (40%) and language impairment (33%).

    There were widespread cerebral white matter alterations (mainly characterized by increased fractional anisotropy), which correlated with abnormal attention and cognitive flexibility. The resting-state fMRI networks analysis showed severely disrupted brain hyperconnectivity and loss of resting-state networks specificity.


    Pre-print: https://www.medrxiv.org/content/10.1101/2021.03.20.21253414v1
     
    Ravn, Arnie Pye, Michelle and 4 others like this.
  2. rvallee

    rvallee Senior Member (Voting Rights)

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    I'm not really clear on what "quantitative analyses confirmed symptoms of" means. There is no means to verify any of those symptoms beyond self-reports. Also fatigue was "validated" with CFQ.

    Discussion:
     
  3. Arnie Pye

    Arnie Pye Senior Member (Voting Rights)

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    I'm not clear what the above phrase means. "Functional" means that something is, effectively, made up. So how can imaging show up something imaginary?
     
  4. Ravn

    Ravn Senior Member (Voting Rights)

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    Haven't read the paper, only looked at the graphs, one of which showed the results of a "trail making test". No idea what that was so looked it up. Wikipedia says:
    https://en.wikipedia.org/wiki/Trail_Making_Test

    The highly educated Covid cohort in this study did particularly badly at the second one.

    I suspect this trail making test would show cognitive deficit in ME, too. I've never taken the test but would predict that I'd do ok on the numbers-only one as long as I took it on a better day when well rested but that I'd slow down noticeably in PEM.

    The combined numbers-letters test I suspect I'd struggle with even on a good day. And on a bad day I'm not sure I can recall the order of the alphabet, certainly not at speed.
     
  5. adambeyoncelowe

    adambeyoncelowe Senior Member (Voting Rights)

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    Functional has at least two meanings in science. It can mean the function of on organ or bodily system, such as the brain, or functional in the sense of FND. In this case, they seem to mean functional in terms of connectivity and the results of a fMRI.

    Technically, FND is supposed to be a problem with functioning as opposed to structure ('software versus hardware'), but there's loads of additional baggage layered on top from when it was called conversion disorder, so it simultaneously means more and less than the normal meaning.
     
  6. Ravn

    Ravn Senior Member (Voting Rights)

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    I think 'functional' in this context just refers to the images you get from fMRI. I've only a vague notion of what fMRIs show but broadly speaking they show brain activity(=function) as opposed to (or in addition to?) brain structure.

    'Functional' is one of those words that are perfectly fine in their original sense but whose meaning has been badly twisted by those with an interest in sowing confusion.

    ETA: cross-posted with @adambeyoncelowe
     

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