Asked to comment on the review by Dr. Bagert and colleagues, Dr. Zamboni expressed some exasperation that the review again does not represent actual new evidence, but is a review, including opinion pieces.
"Until a few years ago, the Archives of Neurology had a section of great interest [called] Controversies, where the reader had the opportunity to consider different visions," said Dr. Zamboni, who is director of the Vascular Diseases Center at the University of Ferrara, Italy.
"Nowadays, countless editorials and opinion articles about CCSVI have been invited in journals of clinical neurology with no chance to reply. This habit, certainly not academic, helps to make me a defendant in science, just to get reported in 30 peer-review articles an underdeveloped aspect of MS research," he told Medscape Medical News.
In their review article, Dr. Bagert and colleagues refer to the Bradford Hill Criteria that are used to assess scientific evidence of causation in biological systems and suggest that in this case, "there is very little validated scientific evidence to support the theory that CCSVI is the cause of MS, especially among the criteria of biological plausibility, coherence, and analogy."
To this point, Dr. Zamboni responds that he would like to see the authors apply the Bradford Hill Criteria, citing exclusively original articles and not editorials and opinions. If his own work is scientifically inaccurate by these criteria, then so is much of the epidemiologic data in other aspects of MS, he says, where studies are equally inconsistent in sample sizes and methods of data collection.
Of the studies published to date on CCSVI, despite the high variability, MS is associated with CCSVI in an average of 80% of cases vs 10% of the healthy population, Dr. Zamboni asserts.
"Furthermore, with respect to the biological plausibility and the coherence of Bradford Hill Criteria, the autoimmune theory cannot in turn explain several vascular aspects well detailed in the MS literature," he told Medscape Medical News.