Chronic Cerebrospinal Venous Insufficiency (CCSVI)
From MSAA’s MS Research Update 2015
Written and compiled by Stephen Krieger, MD
From approximately 2009 through 2013, the Chronic Cerebrospinal Venous Insufficiency (CCSVI) theory of MS pathogenesis received considerable attention. The evidence continues to increase that occlusions/obstructions of the vascular system in cerebrospinal veins (certain veins located in the head and neck), imaged with ultrasound and magnetic resonance venography, do not appear to be related to MS.
Reports from an ongoing study at the University of Texas Health Sciences Center in Houston showed that people with and without MS had abnormalities consistent with CCSVI, and that this abnormality was not found to be more common in people with MS. The group used strict ultrasound criteria definitions, and concluded that their tests – using neurosonography and magnetic resonance venography – did not support the concept that CCSVI is causally involved in MS.
Several vascular-intervention procedures to address the reported venous narrowing in MS are being studied. However, these procedures have also been offered in clinical practice, outside of the safety oversight inherent in clinical trials. Shortly after the American Academy of Neurology’s (AAN) meeting in mid-2012, the FDA issued an alert about risks, including death, associated with these surgical treatments of CCSVI.
The FDA Safety Communication regarding CCSVI treatment in MS stated that the FDA believes there is no reliable evidence from controlled clinical trials that this procedure is effective in treating MS. Data to support CCSVI as a clinical entity on its own or its relationship with MS are inconclusive and at times, contradictory. The FDA believes that using these medical devices in CCSVI treatment procedures poses a risk to patients for several reasons.
First, there is no clear diagnostic evidence that CCSVI exists as a distinct clinical disorder or is linked to MS. Second, the venous stenoses seen on imaging tests may be normal variants and not related to a disease process. Furthermore, the safety and effectiveness of using balloon angioplasty devices or stents in the internal jugular or azygos veins have not been established, and that major risks, including death, have been associated with these procedures.
The largest CCSVI study to date was presented at ECTRIMS in the fall of 2012. In the CoSMo study, Comi and Italian colleagues studied nearly 2,000 people with MS and other neurological diseases, as well as healthy controls. Differences in CCSVI between MS and other neurologic conditions and healthy participants were not statistically different, and the study group concluded that the data did not support that CCSVI is a disease connected to MS.
For more information on CCSVI and the FDA’s warning, please refer to MSAA’s online news articles, “FDA Issues CCSVI Treatment Warning” and “CCSVI Update.” These may be accessed by visiting MSAA’s website at mymsaa.org and selecting “News from MSAA” under “MS News,” and then scrolling down to the articles on CCSVI.