Chronic cerebrospinal venous insufficiency in multiple sclerosis - a medical, sociological and media controversy

In 2009, Zamboni et al. coined the term "chronic cerebrospinal venous insufficiency" (CCSVI). On the basis of transcranial and extra-cranial colour-coded Doppler ultrasonography, they operationally defined CCSVI as occurring when at least two out of five "abnormalities" were present. They claimed to find CCSVI in 100 % of 109 individuals with multiple sclerosis (MS) and in none of 177 healthy controls. Zamboni's group subsequently reported an uncontrolled treatment trial of cerebral venoplasty, which was termed the "liberation procedure" and claimed that the procedure benefited people with MS. The Zamboni reports were received with considerable skepticism, regarding both their biological plausibility and the claims of 100 % sensitivity, specificity, positive predictive value and negative predictive value. No investigators have subsequently been able to replicate the Zamboni observations. Although some additional reports have indicated finding venous abnormalities in more MS patients than in other groups, most have either found no association of CCSVI with MS, or else have found substantial numbers of controls, either healthy or with other neurological disease, to have the abnormalities. The original Zamboni reports were widely publicised in the mainstream media, especially in Canada and sparked a raging controversy in the social media. Patients clamoured for trials of cerebral venoplasty and others demanded its availability or travelled around the globe to undergo the procedure. The Canadian Institutes of Health Research have now solicited proposals for a Phase I/II clinical trial. At this point, additional scientific studies, including many funded by the National Multiple Sclerosis Society and the Multiple Sclerosis Society of Canada, are moving toward completion and will hopefully allow a proper judgment of the validity of the concept of CCSVI in relation to MS. In the meantime, it is important that physicians remain respectful of patients' views, but that they are not reticent about expressing their own professional opinions based on available evidence, while emphasising the importance of proper scientific research.