Dr. Zamboni-his frustration with the neurological journals using opinion pieces, not science
August 12, 2011 at 3:22pm
In a recent article in MedScape discussing the OPINION of Dr. Compston that new genes found in MS implicate the immune system only, and preclude a vascular connection, Medscape asks Dr. Zamboni for his opinion on this new research and the recently published negative review by Dr. Bagert (both negative pieces were all over the corporate owned press.)
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 toldMedscape Medical News.
In their article, Dr. Bagert and colleagues argue that a critical look at the scientific methods used in the original studies of CCSVI in MS "reveals several methodological problems with regard to potential bias and confounding."
For example, the MS patients who underwent PTA of stenotic veins had recently initiated disease-modifying therapy, which could have been responsible for the clinical improvement seen.
"In our opinion, this potential confounder is one of the most egregious methodological problems with the initial treatment trial," they write. Another problem, in their opinion, is the lack of a control group and therefore no blinding of neurologists.
Invasive Treatments for CCSVI 'Premature'
Since 2009, invasive procedures, such as angioplasty and stenting of the cerebrospinal veins, have been performed on eager patients with MS, despite a lack of convincing evidence that CCSVI even exists in MS, Dr. Bagert and colleagues note in their article.
To date, 2 deaths in MS patients have been linked to these procedures.
"It is our opinion that until the existence of CCSVI in MS can be independently verified by other investigators, research into invasive treatments of CCSVI should not be pursued," Dr. Bagert told Medscape Medical News.
But Dr. Zamboni disagrees. "As for the use of venous angioplasty in this setting, it is a safe intervention that can provide insight into the pathophysiological underpinnings of this disease," he said.
The conclusion of the authors is to prohibit studies on this treatment, even when the studies are "well designed and ethically approved," Dr. Zamboni points out.
On the contrary, he thinks "a lot of research, conducted with greater humility and a better interdisciplinary attitude, is still needed to find the exact location of venous function in the complex and mysterious context of MS."
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