Natural course of extracranial venous haemodynamics in 52 patients with MS over a median time period of 16

At baseline and at follow-up, for stenosis measurements, method 1 and 2 were used.Method 1 IJVs stenosis as a local CSA reduction of ≥50% across the IJV. Method 2 IJVs stenosis as a ≤0.3 cm2 CSA, measured at the level of the thyroid gland.B-mode anomalies, referring to septum, flap, annulus, web or malformed valve in the lumen of the IJV, indicating stenosis.ΔCSA = CSAsupine – CSAupright.Abbreviations CCSVI, chronic cerebrospinal venous insufficiency; CSA, cross section area; DCV, deep cerebral vein; ECD, echo color Doppler; IJV, internal jugular vein; MS, multiple sclerosis; VV, vertebral vein.