Proposed chronic cerebrospinal venous insufficienty criteria do not predict multiple sclerosis risk or severity

OBJECTIVE: It is still unclear whether chronic cerebrospinal venous insufficiency (CCSVI) is associated with multiple sclerosis (MS), because substantial methodological differences have been claimed by Zamboni to account for the lack of results of other groups. Furthermore, the potential role of venous malformations in influencing MS severity has not been fully explored. This information is particularly relevant, because uncontrolled surgical procedures are increasingly offered to MS patients to treat their venous stenoses. METHODS: In the present study, CCSVI was studied in 84 MS patients and in 56 healthy subjects by applying the Zamboni method for CCSVI identification. RESULTS: We found no significant differences (p = 0.12) in CCSVI frequency between MS and control subjects. Furthermore, no differences were found between CCSVI-positive and CCSVI-negative patients in terms of relevant clinical variables such as disease duration, time between onset and first relapse, relapsing or progressive disease course, and risk of secondary progression course. Statistically significant differences were not found between CCSVI-positive and CCSVI-negative MS subjects by analyzing direct measures of disability such as mean Expanded Disability Status Scale (EDSS) (p = 0.07), mean progression index (p > 0.1), and mean MS severity score (p > 0.1). The percentage of subjects who reached EDSS 4.0 and 6.0 milestones was not different among CCSVI-negative and CCSVI-positive subjects, and no significant correlation was found between severity of disability and number of positive CCSVI criteria. INTERPRETATION: Our results indicate that CCSVI has no role in either MS risk or MS severity.