That's a definitive statement that I don't think you've backed up with solid evidence. It does not explain many aspects of ME/CFS. It can certainly explain some aspects of ME/CFS, and possibly most of the aspects of ME/CFS for some patients, but it hardly explains everything.
I think my statement is correct though, from the theoretical angle. I am not referring to empirical evidence, which as yet there is none for VanElzakker's theory (it will require post-mortem studies to provide empirical evidence); rather I am talking about his theory being the first all-encompassing theoretical biomedical model of ME/CFS that I have come across.
Out of all the ME/CFS theories that you have read over the years, have you ever come across any theory that offers an explanation of the entire ME/CFS disease process from beginning to end, tracking all the biochemical mechanics from the initial infection, right to the end symptoms of ME/CFS?
VanElzakker's theory provides a model to understand the entire biochemical route, detailing how a viral infection can ultimately lead the end symptoms of ME/CFS. Whether this theory turns out to be right or wrong, in any case, it is quite astounding that it offers this explanatory scope. That just that scope in itself makes it very interesting as a theory.
Can you think of any other ME/CFS biomedical model with the same scope? Let me know if you find one.
Most importantly, it does not convincingly explain the defining characteristic of ME/CFS -- PEM/PENE as described in the ICC. Yes, I know you think it does, but your argument is based on defining PEM as exercise intolerance and extended fatigue, which is not very convincing. Show me evidence that sickness behavior as seen in many other illnesses results in failed 2-day CPET tests as shown in ME/CFS and I might be more willing to accept your theory.
What I said was: there is enough there to suggest that PEM may well be a sickness behavior symptom, but that more research would be needed. Perhaps we need to search through more literature on cancer sickness behavior symptoms, and examine more closely the PEM they get. The authors of the
Maes study stated that they think PEM probably also occurs during sickness behavior.
And note that it would not matter if the PEM in cancer was not as severe, or not quite the same, as the PEM in ME/CFS. These are different diseases, so their precise manifestations may vary a little. The nature and severity of PEM varies greatly even among ME/CFS patients.
In ME/CFS, I would guess that one reason the PEM can be more severe than the PEM of cancer is because in ME/CFS, exercise could well lead to viral reactivation (in the vagus), which I expect would greatly worsen the PEM by worsening the sickness behavior. Whereas this cannot happen in cancer.
And although I said earlier that sickness behavior likely cannot explain the OI manifestations in ME/CFS, I forgot to mention that nevertheless,
the vagus nerve infection hypothesis as a whole may well be able to explain OI.
The following explanation is my idea, not VanElzakker's, but I think it is possible that a vagus nerve infection might cause the OI:
Think about it: the vagus nerve is the central nerve of the parasympathetic side of the autonomic nervous system. So if this nerve is infected, as Michael VanElzakker posits, not only could this infection trigger sickness behavior, but conceivably, the infection might also render the nerve dysfunctional (via triggering an autoimmune attack on the nerve, for example), which then gives rise to dysautonomia and thus orthostatic intolerance (OI) symptoms.
So this is where the vagus nerve infection becomes very interesting: this infection may cause both sickness behavior, which explains the bulk of ME/CFS symptoms, and also OI, which covers the remaining ME/CFS symptoms.
I know these are early days for VanElzakker's theory, and I know there is no evidence to support my conjecture that a vagus infection might cause the dysautonomia and OI in ME/CFS; but I am just attempting to show that the vagus infection theory is potentially consistent with every symptom seen in ME/CFS.
And it is an eminently testable theory: once post-mortem studies are performed, so that the vagus nerve in ME/CFS patients can be checked for infection, we will know whether VanElzakker's theory is right or wrong.
Thank you for your lecture.
My pleasure.
Did you fall asleep during the lecture though, and miss all the salient details! You seem to be raising points that have already been covered.