Each of these three points were once believed to be factual. We now know they were wrong, dead wrong.
But the repercussions of these inaccurate beliefs linger today.
These changes to the brain occur early in MS. Researchers can see the slowed blood flow and hypoperfusion. They can study fMRI images. 7Tesla imaging (Ge, et al) has allowed researchers to see the microscopic vascular changes that happen to the veins in the MS brain.
The physical changes to the brain are caused by a disease process. They are not psychological or imagined. The disease comes first, and the brain damage follows.