I get the impression that the dispute about CCSVI is a common place without the possibility of bringing out the ongoing contributions that emerge from the literature. This appears especially when some studies which denies the contribution of CCSVI to neurodegeneration, show an unexpected and unusual media coverage. This of course generates confusion among patients. But also among colleagues who do not have cerebral venous return as primary interest.
In short, there are 3 meta-analyses available from:
1. Laupacis A, Lillie E, Dueck A, et al. Association between chronic cerebrospinal venous insufficiency and multiple sclerosis: a meta-analysis. CMAJ 2011;183:E1203-12.[Pubmed]
2. Tsivgoulis G, Sergentanis TN, Chan A, et al. Chronic cerebrospinal venous insufficiency and multiple sclerosis: a comprehensive meta-analysis of case-control studies. Ther Adv Neur Dis 2013.[Full-text]
3. Zwischenberger BA, Beasley MM, Davenport DL, Xenos ES. Meta-analysis of the correlation between chronic cerebrospinal venous insufficiency and multiple sclerosis. Vasc Endovasc Surg 2013.[Pubmed]
All the 3 above-mentioned meta-analyses confirm a significant prevalence of CCSVI in MS. Only six out of 19 comparable studies deny the association between CCSVI and multiple sclerosis. But while the first two meta-analysis showed heterogeneity among the studies, the third demonstrated clearly a significant double risk in having MS when CCSVI is detected, without any heterogeneity. The mass media should require a good communication of Science when scientific press releases are solicited. In controversy regarding prevalence and risk factors, to consult meta-analysis is a good tool to balance the communication.