Two new studies recently reported in the Annals of Neurology have cast doubt on the theory that a vascular condition known as chronic cerebrospinal venous insufficiency (CCSVI) contributes to the development of MS. The Annals of Neurology is a journal published on behalf of the American Neurological Association.
Florian Doepp, M.D., and colleagues in Germany performed an extended extra- and trans-cranial color-coded sonography study on 56 MS patients (36 female; 20 male) and 20 control subjects (12 female; 8 male). The analysis included extra-cranial venous blood volume flow (BVF), internal jugular vein (IJV) flow analysis during Valsalva maneuver (VM), as well as tests included in the CCSVI criteria.
Results showed that blood flow direction was normal in all participants, excluding one subject with relapsing-remitting MS. Furthermore, the research team noted that BVF in both groups were equal in the supine body position. In summary, the researchers determined that none of the study participants fulfilled more than one criterion for CCSVI.
A second study by researchers at Umeå University in Sweden also concluded that CCSVI does not contribute to the development of MS. The Swedish research team led by Peter Sundström, M.D., Ph.D., tested the vital component of the CCSVI theory - the obstructed IJV flow - in 21 MS patients and 20 healthy controls using magnetic resonance imaging with phase contrast (PC-MRI).
The researchers found no significant differences between the MS group and control group relating to total IJV blood flow. "Our study found no support for using endovascular procedures such as angioplasty or stenting to treat MS patients," Dr. Sundström says.
Neurologist Ben Thrower, M.D., the MSF’s senior medical advisor, notes that interest in CCSVI and how it might relate to MS has been very high over the past several months.
“Studies by doctors Zamboni and Zavadinov have shown that abnormal venous blood flow termed CCSVI is more common in people with MS versus control groups. There has also been great interest in treating CCSVI with angioplasty or stents. However, the MS/CCSVI theory has not been without its critics. These two studies will certainly add fuel to that criticism,” he says.
“The two studies combined looked at 77 people with MS and found no evidence of venous blood flow abnormalities. Other studies are ongoing. Until the issue is sorted out a little more clearly, I would urge people to be cautious in pursuing the diagnosis or treatment of CCSVI outside of formal clinical trials,” Dr. Thrower says.