The venulitis article! That was an interesting one.
This review of the venous pathology associated with MS describes a hypothesis that the pathogenesis of the venous disease could be initiated by a respiratory infective agent such as Chlamydophila pneumonia, which causes a specific chronic persistent venulitis affecting the cerebrospinal venous system. Secondary spread of the agent would initially be via the lymphatic system to specifically involve the azygos, internal jugular and vertebral veins.
So the location of the venulitis is suspected to be in the usual CCSVI veins: azygous and internal jugular, as well as the vertebral veins.
Would there be visual evidence of inflammation on phlebography if there was venulitis?
One of the interesting things is that some bacteria or viruses do better in lower temperatures. With our autonomic system out of whack in pwMS, some of us tend to have a lower-than-normal body temperature, and some of us are on immune-suppressing drugs, which might create a nice friendly environment for bacteria or viruses.