Back in 2009, there was a single poster presentation at ECTRIMS, by Dr. Zamboni. The presence of CCSVI at ECTRIMS has been growing year by year. When the majority of the research presented is negative, it's hard to be excited about that, especially when we've seen more positive findings presented elsewhere.
Dr. Hubbard has a letter from Dr. Sinan repudiating the work of the neurologist partially associated with his study: http://hubbardfoundation.blogspot.com/
He lists the abstracts but it is hard to make much of more ultrasound studies with inconclusive or negative results. There was a cadaver study of normal people showing normal extracranial veins, but those researchers did not also look at MS patients, or at least not in this abstract. There is a new tool called photoplethysmography that can measure blood flow in the capillaries of the brain, and they tested it after compressing the IJV in MS patients and they found abnormalities. There is Dr. Fox's work on hydration, which seems to aim to write off CCSVI abnormalities in flow as being the result of dehydration. Dr. Simka compared ultrasound to catheter venography in MS patients and normals and found that it correlated poorly. It's interesting that he had normal controls for the invasive catheter venography, we have not seen much about how these veins look in normal healthy people.