Chronic Cerebrospinal Venous Insufficiency: A Failed Concept

I appreciate the response and interest to our recent article regarding chronic cerebrospinal venous insufficiency (CCSVI) in multiple sclerosis (MS) a failed concept. Rasman has eloquently pointed out a number of important points of discussion surrounding the controversy behind the concept of CCSVI. The main point being the high degree of variability behind the diagnostic ultrasound (DU) criteria that define CCSVI and the inability of other investigators to replicate the data initially published by Zamboni et al. [1]. Zamboni et al. [1] reported that diagnosis of chronic cerebrospinal venous insufficiency required fulfillment of at least 2 of 5 ultrasound criteria: Reflux (71% vs. 0%), B-mode evidence of internal jugular vein stenosis (37% vs. 0%), absent flow detectable by doppler ultrasonography in the internal jugular or vertebral veins (52% vs. 3%) and reversed postural flow in the internal jugular vein (55% vs. 11%). When these criteria were applied in the evaluation of 109 patients with multiple sclerosis and 177 controls, each patient was deemed to meet at least 2 criteria, whereas none of the control participants did so. The sensitivity, specificity, and positive and negative predictive values for the proposed criteria were each 100%. To date, not one single published report has been remotely close in being able to reproduce these findings. The basic premise of defining a scientific concept is reproducibility of an observed finding. It is entirely surprising that the across numerous medical subspecialties, a set of observed criteria reported to have 100% sensitivity lacks a corroborating study. Only Zamboni and his associates are able to replicate CCSVI in MS patients. Numerous prominent groups across the globe, to a larger scale, have found no evidence of CCSVI in MS patients as defined by Zamboni's DU criteria and standards when sonographers and clinicians were double and triple blinded [2-12]. I believe there are two critical issues that cause the variability. The diagnostic criteria proposed for chronic cerebrospinal venous insufficiency are overly inclusive and nonspecific. As such up to 25% of normal individuals in certain studies met criteria for CCSVI [13]. More importantly, the reported Zamboni criteria has inherent pathophysiologic implausibility when used to define a causal relationship between CCSVI and MS. To break down individually, let's examine the technical and physiologic concerns regarding the criteria for reflux. For one, Barreto et al. [10] did not obtain spectral Doppler measurements of duration for reflux, a fundamental technique to determine presence of …