Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Neurological Entity?, 2021, Gandasegui et al

Abstract
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a disorder of unknown physiopathology with multisystemic repercussions, framed in ICD-11 under the heading of neurology (8E49). There is no specific test to support its clinical diagnosis.

Our objective is to review the evidence in neuroimaging and dysautonomia evaluation in order to support the neurological involvement and to find biomarkers serving to identify and/or monitor the pathology.

The symptoms typically appear acutely, although they can develop progressively over years; an essential trait for diagnosis is “central” fatigue together with physical and/or mental exhaustion after a small effort. Neuroimaging reveals various morphological, connectivity, metabolic, and functional alterations of low specificity, which can serve to complement the neurological study of the patient.

The COMPASS-31 questionnaire is a useful tool to triage patients under suspect of dysautonomia, at which point they may be redirected for deeper evaluation.

Recently, alterations in heart rate variability, the Valsalva maneuver, and the tilt table test, together with the presence of serum autoantibodies against adrenergic, cholinergic, and serotonin receptors were shown in a subgroup of patients. This approach provides a way to identify patient phenotypes.

Broader studies are needed to establish the level of sensitivity and specificity necessary for their validation. Neuroimaging contributes scarcely to the diagnosis, and this depends on the identification of specific changes. On the other hand, dysautonomia studies, carried out in specialized units, are highly promising in order to support the diagnosis and to identify potential biomarkers.

ME/CFS orients towards a functional pathology that mainly involves the autonomic nervous system, although not exclusively.

https://www.mdpi.com/1648-9144/57/10/1030

eta:
paper reviewers report and authors response
https://www.mdpi.com/1648-9144/57/10/1030/review_report

 

Maybe, just maybe, this is one of those papers where in 10 or more years time it will be possible to look back and say, at least for neurology, that is where it all began to change.

 

I've always been very surprised at how little neurologists understand the neurological symptoms of ME. I'm not talking about the fatigue, or the brain fog, those are not recognized as neurological symptoms in the classical sense and they can always just they are subjective or whatever. But even the symptoms that are strictly neurological (disautonomia, POTS) are just not understood at all.

I was recently hospitalized in a top neurological istitute (recognized as the best of the best, in a country with very good health care) and they tried to make me do an EEG where i would have to sleep... on a Recliner Chair. Obviously given that i have POTS it's impossible for me to fall asleep in partial orthostatism, with a pounding heart, heavy breathing, sweating and with adrenaline in my body. I thought it was extremely obvious and that there was supposed to be a bed but they made a mistake, and when i would tell this to the neurologist he would say "oh whoops". But no. I explained to him the situation and he was puzzled. He could not understand why someone with orthostatic intolerance wouldn't be able to fall asleep on a surface that isn't horizontal.

This to me shows that that even the best neurologists have no clue at all of these neurological symptoms, and it just seems bizarre to me. But, i suppose when you accurately try your best to avoid studying a specific illness over decades this is the result.

 

What do they mean by "functional pathology"? I thought the definition of functional illnesses were that they lacked a known pathology? Do they mean functional in another sense here?

 

I think they are using pathology in the widest sense of something wrong. A bug written in to Microsoft Word is then a 'pathology' even if it does not mean anything wrong with your computer.

They appear to be using functional in the honest sense of a 'software issue' of this sort rather than due to childhood trauma or emotional frailty or whatever - as judged by the focus on autonomic system.

 

This is necessary. I dont think questionnaires are reliable or objective though (EDIT for experimental protocols - obviously for selecting cohorts patient reports are an essential first step and also for clinical approaches engaging with the patient is important but experimental design needs to stand back a little from clinical practices).

I recently read a paper abstract by Leonard and Zinn (thanks to feed from Dr Fluks) using qualitative quantitative EEG which seems potentially to be a more objective method of observing autonomic anomalies associated with ME.

Cortical autonomic network connectivity predicts symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

I reported it here as I thought it was relevant to this discussion.
https://www.s4me.info/threads/corti...predicts-symptoms-in-me-cfs-zinn-jason.22870/

[re: edits, sorry I have been a bit wobbly lately and mixed up "qualitative" and "quantitative" for some reason best known only to my fingers!]

 

"functional" is kept intentionally ambiguous for political reasons. The meaning can range from "it's definitely psychological and there's nothing wrong" to "this organ is not functioning properly and we don't know why, well at least we can't see obvious damage that would explain it". That way papers can be published and the authors can appease everyone. From what i've seen over the years, usually in "functional neurological disorders" doctors think there is a psychological component but are at the same time not completely opposed to biological research (similar deal with psychiatric illness). People like Sharpe and Wessely who go around saying "nonono it's completely psychological if you do biological research you are a fool" are definitely outliers. At some point they realized this too so they changed the narrative to "well actually our research is biological too ". It's hard to argue with that because the definitions are intentionally kept very vague and conmen can easily thrive in such environment..