By: Dr. James Stark
Chronic Cerebrospinal Venous Insufficiency (or CCSVI) is a recent theory that Multiple Sclerosis is in some way related to constriction of veins in the brain and/or spinal cord. The theory first came to attention to the MS community following a 2009 publication by Italian vascular surgeon, Pablo Zamboni. In that publication, Dr. Zamboni reported that all of the MS patients studied fulfilled his criteria while people without MS did not. This was met with widespread speculation throughout the MS community because of the methods used as well as the staggering results. Such a radically new outlook on MS clearly warranted further study.
Since Zamboni’s publication in 2009, numerous studies have reported conflicting results:
- Doepp et al reported in 2010 that none of the 56 MS patients investigated with Doppler ultrasound met the criteria for CCSVI.
- Similarly, Sundstrom et al (2010) and Wattjes et al (2011) performed MRI’s of the veins of MS patients and controls and found no difference between these groups.
- Baracchini et al reported in 2011 that patients at the onset of their MS diagnosis exhibited no differences to controls in venous abnormalities. Baracchini further reported later in 2011 that there was no association between progressive forms of MS and venous stenosis.
- Meyer-Schwickerath et al (2011) report no difference in ophthalmologically measured intracranial venous pressure between MS patients and controls.
- Centonze et al (2011) attempted to replicate Zamboni’s findings in another Italian cohort and, again, found no difference between MS patients and controls. Furthermore, compared to the patients that did exhibit evidence of some venous abnormality, no differences were found in terms of disease duration, time between onset and first relapse, relapsing or progressive disease course, risk of secondary progression course, Expanded Disability Status Scale (EDSS), mean progression index, and mean MS severity score.
- The largest study to date on CCSVI and MS comes from a group at the University of Buffalo. Their well-designed study, consisting of a total of 499 people, found that 56.1% of MS patients fulfilled CCSVI criteria. However, 42.3% of subjects with other neurologic diseases also fulfilled the criteria as did 22.7% of normal subjects.
- Auriel et al (2011) and Tsivgoulis et al (2011) also found normal blood flow in all MS patients using Doppler ultrasound.
- Marder et al (2011) studied veterans with MS using Doppler ultrasonography and found no difference between MS patients and controls.
- Tsivgoulis et al (2011) recently published a study in the journal, Neurology. This study used Doppler ultrasound with 42 MS patients and 43 controls and found no evidence of venous stenosis in the cervical veins of patients or controls.
A variety of studies have also been published regarding the efficacy and safety of a procedure to correct venous stenosis in MS patients. Data from those studies have not been included in this article and will be reviewed elsewhere.
There are a number of theories to account for these conflicting results. Methodological differences between the studies, subjectivity of ultrasound interpretation and other biases may account for some of the differences. More research, conducted in well-controlled clinical trials, is underway, which will hopefully help us better understand the relationship between CCSVI and MS.