What Causes CCSVI?

Everyone who is diagnosed with multiple sclerosis (MS) wonders at some point what caused them to have MS – was it something we were born with, something we ate, something we did (or didn’t do)? Now there is a theory that chronic cerebrospinal venous insufficiency (or CCSVI) is the cause of MS. While the CCSVI and MS link is still in the early stages of research (and acceptance by much of the medical community), let's look at what the proponents of this theory, Dr. Paolo Zamboni and his colleagues, say about the causes of CCSVI:

Congenital "Plumbing Problem" Idea

According to the theory, CCSVI is the result of a "plumbing problem" in the veins of people with MS. It is hypothesized that this is something that we (people who eventually develop MS) are born with – malformed or narrow veins that get progressively narrower as time goes on. Since there is a genetic link to MS, this seems plausible.

Autoimmune Response to Infection Theory

It is also possible that these malformed veins are actually the result of an autoimmune attack on the valves in the cerebral venous system, which causes chronic inflammation and scarring. There are some who theorize that this could be triggered by any number of viruses or bacteria, as there are links between MS and Chlamydia pneumoniae and “neurotropic” viruses like measles, rubella and varicella (among others). There is a VERY strong correlation between Epstein Barr Virus and MS, as well.

How Do We Know That MS Didn’t Cause the CCSVI?

Since the CCSVI/MS link has come out, many people have wondered if it could be the other way around – maybe MS was causing CCSVI, rather than the CCSVI leading to MS and its symptoms.

Of course, this hasn’t been disproven, but it seems unlikely to the authors of the study. There seemed to be no difference in the extent of the stenosis in people who had been on treatment or never been on treatment for their MS. Dr. Zamboni and colleagues say that it would be logical for disease-modifying therapies to have some positive impact on the progression of the venous malformations and narrowing if the MS was causative. They also use this as evidence that CCSVI is not a side effect of disease-modifying therapies, either.

Further cited as support of their theory, CCSVI also happens in different parts of the body, such as the legs and in the spine. However, if MS was causative for CCSVI (rather than the other way around), it would not explain these other cases of CCSVI.

In my opinion, there is pretty strong evidence that there is a link between MS and CCSVI. It also seems quite logical that CCSVI could cause MS, rather than MS causing CCSVI, based on the research. However, it is clear that much more research needs to be done before anything is definitive. It would be very interesting, for instance, to be able to look at the "natural history" of CCSVI and the corresponding MS - that is, to monitor how the malformed or narrowed veins changed over time and at what point this lead to lesions and corresponding MS symptoms.

Of course, the first step in extensive (and very expensive) research and exploration of a new theory is acknowledgment that there might be something there. That hurdle has been cleared with the CCSVI link - enough people are convinced to move this idea forward. Now, the rest of us are watching, waiting and many people with MS are willing to participate in the discovery process.

_Sources:

Brettschneider J, Tumani H, Kiechle U, et al. IgG antibodies against measles, rubella, and varicella zoster virus predict conversion to multiple sclerosis in clinically isolated syndrome. PLoS One. 2009 Nov 5;4(11):e7638.

Singh AV, Zamboni P. J Cereb Blood Flow Metab. 2009 Sep 2. Anomalous venous blood flow and iron deposition in multiple sclerosis.

Zamboni P, Galeotti R, Menegatti E, Malagoni AM, Tacconi G, Dall'Ara S, Bartolomei I, Salvi F. J Neurol Neurosurg Psychiatry. 2009 Apr;80(4):392-9. Chronic cerebrospinal venous insufficiency in patients with multiple sclerosis.