Cognitive-communication difficulties in adults with Long COVID, 2023, Cummings (has ME/CFS control group)

[Dolphin]

Free full text:
https://library.oapen.org/bitstream...257318_10.4324_9781003257318-5.pdf?sequence=1

Recruitment to the study was conducted by means of posts on Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) support groups. The participants were adults who resided in the UK, Ireland, Canada, USA, Australia, Brazil, and Belgium. They emailed me directly after reading posts about the study. All healthy (non-COVID) participants were recruited from amongst academic colleagues, former students, and personal contacts in Hong Kong, mainland China, Belgium, Ireland, and the UK. Each participant signed a consent form and received an information sheet about the study. COVID participants were asked to complete a 38-item questionnaire about their lifestyle and general health prior to COVID infection and the onset and development of their COVID illness. A similar questionnaire was completed by ME/CFS participants. The study was approved by the Human Subjects Ethics Sub-Committee of The Hong Kong Polytechnic University.

 

[Peter T]

From the discussion section

Speech, language, swallowing, and cognitive problems are well-recognised seque- lae of infectious disease in children and adults (Cummings 2019). It is therefore not surprising that dysarthria, dysphagia, and cognitive and language disorders are reported in adults with severe COVID disease requiring hospitalisation (Dawson et al. 2020; Ellul et al. 2020; Priftis et al. 2020, 2021). What is remarkable, how- ever, is that the adults in this study, who were not hospitalised and had milder forms of infection, also present with marked cognitive-linguistic difficulties.

Moreover, these difficulties were evident many months after the onset of COVID illness when one might expect any cognitive-linguistic disturbance related to acute infection to have resolved. Whilst there has been some evidence to date of cognitive deficits in people who have recovered from COVID infection (Hamp- shire et al. 2021) and in people with Long COVID (Graham et al. 2021), this is the first study to find evidence of specific language deficits in individuals with Long COVID (see also Cummings 2021b).

A clear finding of this study is that adults with Long COVID have reduced discourse informativeness. The informativeness of spoken discourse in partici- pants with Long COVID was significantly reduced relative to healthy participants in the study, COVID participants who did not report cognitive deficits (“brain fog”), and participants with ME/CFS. This latter finding suggests that reduced informativeness is not a consequence of the performance limitation that extreme fatigue in Long COVID can place on cognitive processing.

It is good to read a study attempting to measure the language/communication deficits of Long Covid and ME.

 

[It's M.E. Linda]

Very grateful to Prof Cummings for emphasising these points, as I requested (my bolding):

“By the time they came forward to participate, they had already experienced considerable improvement of their cognitive-linguistic difficulties. If these same participants had been assessed several months earlier, it is likely that their cognitive-linguistic problems would have been more severe still. These same remarks apply with equal relevance to the ME/CFS participants in the study. Many people with ME/CFS are too debilitated by their condition to participate in research studies. Consequently, the ME/CFS participants who participated in the study are also likely to have milder difficulties than the ME/CFS population in general (but even then, their letter fluency performance was significantly weaker than that of healthy participants). It is likely that both groups of participants occupy the milder end of a spectrum of cognitive-linguistic difficulties which also has more severe manifestations.”

 

[adambeyoncelowe]

Very grateful to Prof Cummings for emphasising these points, as I requested (my bolding):

“By the time they came forward to participate, they had already experienced considerable improvement of their cognitive-linguistic difficulties. If these same participants had been assessed several months earlier, it is likely that their cognitive-linguistic problems would have been more severe still. These same remarks apply with equal relevance to the ME/CFS participants in the study. Many people with ME/CFS are too debilitated by their condition to participate in research studies. Consequently, the ME/CFS participants who participated in the study are also likely to have milder difficulties than the ME/CFS population in general (but even then, their letter fluency performance was significantly weaker than that of healthy participants). It is likely that both groups of participants occupy the milder end of a spectrum of cognitive-linguistic difficulties which also has more severe manifestations.”

Very helpful caveats in there, I think.

 

[Hutan]

The chief reason COVID and ME/CFS control groups were used in the study was that the debilitating fatigue that is a feature of Long COVID is a potential performance limitation on language and cognition. Fatigue adversely impacts cognitive-linguistic performance in healthy individuals and in individuals with conditions like ME/CFS. It is noteworthy that language and cognitive problems are also documented in adults with ME/CFS (Moss 1995; Daly et al. 2001; Park et al. 2001). In the absence of COVID and ME/CFS control participants, the reduced performance of COVID experimental participants on the tasks in the study may simply reflect the fatigue of these participants rather than any COVID- related neurological dysfunction.

A clear finding of this study is that adults with Long COVID have reduced discourse informativeness. The informativeness of spoken discourse in partici- pants with Long COVID was significantly reduced relative to healthy participants in the study, COVID participants who did not report cognitive deficits (“brain fog”), and participants with ME/CFS. This latter finding suggests that reduced informativeness is not a consequence of the performance limitation that extreme fatigue in Long COVID can place on cognitive processing.

It is well known that fatigue can serve as a performance limitation on language and cognition. To determine if this factor was contributing to the cognitive-linguistic difficulties of adults with Long COVID, a group of participants with ME/CFS was included in the study. ME/CFS is another clinical condition in which sufferers experience debilitat- ing fatigue. Except for letter fluency, the performance of the ME/CFS partici- pants on the tasks in the study did not differ significantly from that of healthy participants. Meanwhile, the ME/CFS participants performed significantly better than COVID experimental participants on tests of immediate and delayed recall and informativeness during Cinderella narration. Although the ME/CFS control group was comparatively small, these findings suggest that fatigue may not be playing a significant role in the cognitive-linguistic difficulties of adults with Long COVID in this study.

I'm not sure about this study. There seems to be an assumption that the cognitive difficulties of Long Covid are additional to the issues caused by fatigue, but that the cognitive difficulties in ME/CFS are solely due to fatigue. So, by having ME/CFS controls, it is possible to subtract out the impact of fatigue. I don't think there is evidence for that assumption.

 

[ahimsa]

Interesting. I searched on twitter and found this webinar scheduled for November 22:

https://ealthy.com/product/cognitive-linguistic-difficulties-in-adults-with-long-covid/

The COVID-19 pandemic has had a disproportionate impact on health workers, with the World Health Organization reporting some 115,500 deaths in health and care workers between January 2020 and May 2021 (WHO, 20021).

Even in those health workers who do not develop serious disease, there is a high prevalence of the Long COVID syndrome which has implications for return to work and performance of occupational duties (Gaber et al., 2021).

Cognitive-linguistic difficulties referred to as “brain fog” are a prominent feature of the Long COVID syndrome, and often persist in sufferers long after physical symptoms have resolved (Cummings, 2021).

This talk examines the nature of these difficulties by examining language data from 92 adults with the Long COVID syndrome.

One third of these adults are health and care workers who contracted SARS-CoV-2 through occupational exposure.

These adults reported significant problems with cognition and language following acute COVID illness, with many unable to return to work (Cummings, 2022).

The talk explores their self-reported cognitive-linguistic difficulties and relates them to problems with verbal recall, verbal fluency, and informativeness during discourse production.

 

[Hoopoe]

I speak slowly to hide the difficulty I have in constructing sentences at normal speed. In part this is word finding difficulties.

 

[Jonathan Edwards]

I think there is a major problem with the method of recruitment in this study - making it self fulfilling. No doubt people with Long Covid have cognitive problems but this is not the way to measure it. The idea that somehow it is dissociated from the fatigue of ME/CFS also seems dubious.

 

[Mij]

Does LC cognitive 'fatigue' negatively affect their gait, speech and leg muscles? I feel as though I've climbed a mountain after talking too much. My leg and arm muscles are exhausted/sore and I can barely stand up.

 

[bobbler]

I'm not sure about this study. There seems to be an assumption that the cognitive difficulties of Long Covid are additional to the issues caused by fatigue, but that the cognitive difficulties in ME/CFS are solely due to fatigue. So, by having ME/CFS controls, it is possible to subtract out the impact of fatigue. I don't think there is evidence for that assumption.

Indeed. I also think that the author needs to remember how tenacious and smart (ie in comparison to most of the 'experts' who believe they can give 'tips' in their little courses) most with ME are at learning to function at a higher level than their illness actually should allow them to by basically using all sorts of strategies.

More below. But the following plays into all of that.

But the other point to note is that there is a vast different between 'before and after the 'cliff'' for me. ANd that has varied substantially in how long I have before the cliff based on severity of ME. What I've heard some say about Long COvid (but don't feel well informed on) is that things like this can be constant - like lower-level constant rather than this vast difference between 'rested' then 'boom' after 10mins. Or for those milder then it could be many hours. Or even days - but then catch them in that cognitive PEM and it's a different matter.

So there is the comparing like-with-like issue in saying it isn't the same. It's the same old chestnut of needing to map PEM and 'where in their threshold' someone with ME is (as well as severity) to know what they are comparing with. Which is why the 'fatigue' is wrong (PEM is the condition so why didn't they measure it and mention it). And I link back to the 'iceberg being flipped' slides on the following video (Occupational Therapy by SolveME) - watch at around 17min.30 - to say here is our methodology issue still in all this: https://www.s4me.info/threads/solve...re-for-me-cfs-presentation.29520/#post-437280

I really do think these slides and communications making the most of these types of wordings to communicate how the paradigm has been wrong is a breakthrough if we can start linking to short versions of things like this everytime there is something public with comments that misses it on this one.

Some simple reasons on PwME not being like-for-like with LC due to 'experience':
1. They will have generally had a lot longer to get used to these and so you do what you can and learn in a convo to devote your energy to the 'bits that matter' or 'focus on the hard/relevant task and let the other words go' and know that slowing it all down is pretty key - try asking them a complex question though and it becomes more obvious because the 'load' vs the length of time short term memory can hold info means these bits don't add up so you actually see the limits.

2. We've had horrific bigotry, even those of us who think we've had not that bad a time there is no leeway. We had to learn to survive and cover etc - particularly because most of us would have been 'alone' ie covid has many people in a similar 'stage' to them to consult with and feel less unusual. Even when we want to it is not natural for us or probably even possible after all these years of training ourselves to be completely 'out' when you've spent decades getting used to your face being right or other things you don't even realise you do anymore

3. For us noone would listen and gaslighted and deliberately misinterpreted words we very specifically formed to describe things, and gave no leeway on cognitive deficits so we had to become clever at working out how to do it in a different way despite our limitations - society made us 'adapt to them' by basically bullying us about our disability instead of trying to seek to understand when we tried to speak they mocked it. We learned not to waste words, signs of 'dropping off the cliff', how to get micro-rest within a convo, how to 'work norms' in how you describe something by circumnavigating or using hands, diagrams or whatever to 'concept'.

It all depends how the conversation was done - if you have people with certain personalities they control the conversation and force words out of you etc. Others control the conversation and ask direct open questions - and you've no wiggle room round it to hide. EDIT* and some make it easy by 'working with' you. Depending on which of these the interviewer/converser is, you see the vulnerability more or less quickly as you take away all defensive/work-around tools we might reach for and employ.

 

[Sean]

Does LC cognitive 'fatigue' negatively affect their gait, speech and leg muscles? I feel as though I've climbed a mountain after talking too much. My leg and arm muscles are exhausted/sore and I can barely stand up.

Good question.