Centralized Reading Assessment of Chronic CerebroSpinal Venous Insufficiency (CCSVI) in Patients With Multiple Sclerosis and Other Neurological Diseases

This study will retrospectively investigate doppler images from the second phase of the CTEVD trial. 1. To determine the prevalence of CCSVI in patients with MS, compared with the prevalence observed in a control population consisting of Other Neurological Diseases (OND) patients and Healthy Controls (HC) by using blinded, controlled centralized ultrasound reading assessment of 5 Venous Haemodynamic (VH) CCSVI CCSVI Doppler UltraSound (CDUS) criteria. 2. To investigate whether prevalence of CCSVI is different between centralized and local CDUS reading of 5 VH CCSVI CDUS criteria. 3. To investigate the prevalence of CCSVI in patients with MS, compared with the prevalence observed in a control population consisting of OND patients and HC, when bidirectional flow in the intracranial veins and sinuses CDUS criterion is not considered as part of VH CCSVI CDUS criteria. 4. To determine whether prevalence of CCSVI in patients with MS, compared with the prevalence observed in a control population consisting of OND patients and HC differs when using CDUS velocity and flow parameters in the Internal Jugular Veins (IJVs) and Vertebral Veins (VVs). 5. To determine the reproducibility of VH criteria by using of centralized and local blinded, controlled CDUS reading assessment.