Dr. Haacke may have an answer for you regarding your low blood pressure and returning MS symptoms, via his research into Dr. Putnam's writings in the 1950s...
http://www.ms-mri.com/history.phpAs for vascular insufficiency, Putnam discusses this in his 1953 paper (25) entitled: "Cerebral vascular insufficiency" although this paper is about arterial insufficiency. However, he shows that the effects of hypotension can cause significant neurological problems when it leads to a deficit of blood flow to the brain in the presence of already compromised (narrowed) vessels.