Since Zamboni's original research discovering chronic cerebrospinal venous insufficiency (CCSVI) and its 100% association with MS burst into the headlines, the MS community has eagerly awaited follow up investigations to confirm or refute the initial findings.
Several small studies have been published questioning Zamboni's results, but some doubted these findings on the basis that the techniques used to assess CCSVI were not the same as Zamboni's.
The Buffalo group, some of them trained by Zamboni's group, and studying a very large group of people with MS, were felt to be in the best position to shed light on this question.
Finally, after much speculation, their results have been peer-reviewed and published in the eminent journal Neurology. They studied 499 people, 289 with MS, 163 healthy people without MS, 26 people with other neurological diseases, and 21 with clinically isolated syndrome (very early probable MS, but not yet able to be diagnosed).
It should be noted that all scans were done by a single ultrasonographer, but that this researcher was not blinded to the condition of the patients, that is he or she knew which people had MS and which ones did not, introducing bias into the study. The results have significantly diluted initial enthusiasm about the possible causative role of CCSVI in MS.
The prevalence of CCSVI in those with MS was around 56%, in other neurological diseases 42%, in clinically isolated syndrome 38%, and in healthy people 23% (with no difference in this latter prevalence whether the healthy people were related to people with MS or not).
The authors' conclusions were that "These findings point against CCSVI as having a primary causative role in MS" and "These findings suggest that CCSVI may be a consequence rather than a cause of MS". An accompanying editorial stated that "...any CCSVI intervention such as balloon venoplasty should be restricted to a blinded, controlled clinical trial..." These conclusions appear to be balanced and justified; we must await results of the randomised controlled trials currently underway to determine whether angioplasty is of any benefit in MS.t