Venous drainage in multiple sclerosis: a combined MRI and ultrasound study.

BACKGROUND: Chronic cerebrospinal venous insufficiency (CCSVI) was proposed as the causal trigger for developing multiple sclerosis (MS). However, current data are contradictory and a gold standard for venous flow assessment is missing.
OBJECTIVE: To compare structural magnetic resonance venography (MRV) and dynamic extracranial color-coded duplex sonography (ECCS) in a cohort of patients with MS.
METHODS: We enrolled 40 patients (44 ± 10 years). All underwent contrast-enhanced MRV for assessment of internal jugular vein (IJV) and azygos vein (AV) narrowing, graded into 3 groups: 0%-50%, 51%-80%, and >80%. ECCS analysis of blood flow direction, cross-sectional area (CSA), and blood volume flow (BVF) in both IJV and vertebral veins (VV) occurred in the supine and upright body position.
RESULTS: MRV identified 1 AV narrowing. IJV analysis yielded 12 patients for group 1 (30%), 19 patients for group 2 (48%), and 9 patients for group 3 (22%). By ECCS criteria, 4 patients (10%) presented with venous drainage abnormalities. Jugular BVF was different only between groups 1 and 3 (616 ± 133 vs. 381 ± 213 mL/min, p = 0.02). No other parameters in supine position and none of the parameters in the upright body position, apart from the IJV-BVF decrease in groups 1 and 3 (479 ± 172 vs. 231 ± 144 mL/min, p = 0.01), were different.
CONCLUSIONS: Our ECCS data contradict the postulated 100% prevalence of CCSVI criteria in MS. MRV seems more sensitive to detect IJV narrowing compared to ECCS. A measurable hemodynamic effect only exists in vessel narrowings >80%. Our combined data argue against a causal relationship of venous narrowing and MS, favoring the rejection of the CCSVI hypothesis.