Dr. Simka has been looking at CCSVI since 2009. Here's his article on why we've seen such variability in diagnosing CCSVI--because it's different in each patient. The complete article is available at this link as a pdf.
"The research is currently suggesting that CCSVI is not a single entity, but rather a group of different anatomic and functional venous abnormalities. Regarding venous outflow from the brain, a patient can present either with diminished inflow to the internal jugular veins resulting from decreased cerebral circulation or with externally compressed or hypoplastic internal jugular veins or stenotic jugular valves." https://www.dovepress.com/chronic-cerebrospinal-venous-insufficiency-current-perspectives-peer-reviewed-article-JVD


Chronic cerebrospinal venous insufficiency: current perspectives
www.dovepress.com
Peer reviewed article authored by (Simka M). Read article or submit your manuscript for publishing.