Prevalence rates of Zamboni criteria and CCSVI for disease group (HC, MS) and MS subtype. aThe prevalence of CCSVI was significantly higher in the MS group than in the HC group (p<0.001). bThe absence of IJV and/or VV flow (Cr 4) was significantly more frequent in the PPMS form of disease compared with the RRMS form (p<0.005). cB-mode anomalies were the most frequently detected anomalies in MS patients and HCs. Abbreviations: CIS: clinically isolated syndrome; CCSVI: chronic cerebrospinal venous insufficiency; HCs: healthy controls; MS: multiple sclerosis; PPMS: primary progressive multiple sclerosis; RRMS: relapsing-remittent multiple sclerosis; SPMS: secondary progressive multiple sclerosis; Cr: Echo-Doppler criterion.