Studies following up the highly promising work of Zamboni on chronic cerebro-spinal venous insufficiency (CCSVI) seem to add to the confusion about this entity

Experienced Dutch radiologists looking at CCSVI have examined venous anatomy and blood flow using magnetic resonance venography (MRV) in 20 people with MS and 20 matched people without MS. Their findings seem to add more confusion to this contentious area 

The radiologists decided to use MRV because it is a relatively objective imaging technique in contrast to colour Doppler, the technique originally used to describe CCSVI, which is known to be very operator-dependent, that is, the findings vary a lot between different sonographers.

Further some form of venography is necessary before any operative procedure can take place, and so MRV provides a very reliable form of imaging with which to investigate this condition.

Their findings are sure to fire heated debate, as other recent negative studies have done. The research methodology of the study was strong. 

The radiologists who reported the images were experienced and well-published in brain MR imaging, and completely blinded to the clinical state of the subject of the particular image.

Further, the authors declared no conflict of interest, a point of criticism that has been raised about some of the other negative studies. There was no reported receipt of drug company funding in particular. In about half the MS cases and the controls, the venous anatomy was completely normal.

Similarly, in the other half on whom it was abnormal, there was a roughly equal distribution of abnormalities between people with MS and those without. Further, none of the patients, either with or without abnormal veins, had abnormal venous backflow or reflux.

These findings are completely at odds with the original work of Zamboni. They show that a lot of people, both with and without MS, in roughly equal proportions, seem to have abnormal veins in the brain or neck; findings suggestive of abnormal outflow from the brain in these veins seem also to be equally distributed between people with and without MS.

The authors conclude that these venous abnormalities are most likely just variations on normal anatomy rather than causing any illness. It is important for the research community to weigh up all the data coming out of these follow up studies carefully; results of current clinical trials in CCSVI will be particularly important in determining whether CCSVI is a real breakthrough or not. This particular piece of evidence argues against it. 

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