Venous function is a central mechanism of regulation of cell and tissue biology, although there is a lack of study on its influence in the central nervous system (CNS).1 The paper by Zamboni and co-workers (see page 392) illustrates a vascular picture that has not previously been described, correctly defined as chronic cerebrospinal venous insufficiency (CCSVI), strongly associated with multiple sclerosis (MS).2 The picture is characterised by significant obstacles of the main extracranial cerebrospinal veins, the jugular and azygous system, and by the opening of substitute circles. When the venous flow is deviated into collaterals to bypass an obstacle, there exists …