My personal belief is that, like
@jeff_w states in mechanicalbasis.org , that a number of pwME have some form of cervical spine or brainstem compression. But in my opinion, there may be something upstream of this, at least in a number of cases. And I believe that what
@Hip calls the “dual-factor” theory of an infection combined with an environmental factor that suppressed immunity , is consistent with this mechanical theory. The reason I think this is because many people w/ cci diagnoses do not have a genetic connective tissue disorder OR head trauma to explain the damage to their collagen.
So I believe that some environmental variable yet to be discovered is wreaking havoc on connective tissue and also suppressing immunity, to the extent that whatever initial infection people have as a trigger does more damage.
So (infection plus x) > collagen damage > brainstem compression > all ME/CFS symptoms.