We still don't know what's going on for sure, but I have a theory (you knew I would...
I think that the MS brain is in a state of being "almost" oxygen deprived, due to the reflux and build up of deoxygenated blood. So any vasoconstrictive event (high altitude, stress, cold weather) can tip the balance of oxygen getting into the brain and create physical symptoms. As soon as this event stops, oxygen levels can return to "almost" normal, and the symptoms go away.
I think a flare/relapse is when this hypoxic event goes on for awhile...like being at high altitude for a long time, or getting sick, or getting injured...and the damage goes a bit further. Brain tissue dies, the immune system comes in to clean up, you get a full blown relapse.
This is all theoretical- but Dr. Haacke did talk about seeing the lack of oxygen in MS brains, and the tissue death due to hypoxia, with BOLD technology (a means to measure oxygen levels in the brain) and how that fits in with CCSVI.
We're just not seeing the azygos involvement Dr. Z did....and I'm not sure if it's genetics, or length of disease, or age of patient. Dr. Z had a few of his progressive patients at the press conference, and they were older individuals (60s)..so maybe Dr. D is seeing younger individuals. Still more to come.
I also wanted to share that Jeff just went out to play his first jazz gig in over two years!! He's so excited to have energy to perform again....I can't believe it. He just thanked me for changing his life....wow. It's a good night.