I think you are right, we can't discount that the immunomodulators have an effect on MS relapses. The CRABs have turned out to have little to no impact on long-term progression, which surprised researchers. Tysabri is so powerful that I would hope it would have an effect on long-term progression, but even with Tysabri there is a 'rebound effect' when you come off of it, where you're more likely to have a MS attack. I think the reason for this is that while on an immunomodulator, there is an accumulation of iron depositions and deoxygenated dead&dying neurons or glial cells, but the immune system is kept from cleaning them out. This is beneficial because the immune system does create further damage when cleaning up. As soon as the immunemodulator is discontinued, the immune system gets in, and the clean-up/further damage occurs. To me CCSVI theory can dovetail with the existing immune theory, as long as the auto- is dropped off, and CCSVI explanations for things like fatigue are accepted.