Unequal propagation of central venous excess pressure into the different cerebral and spinal venous drainage systems is the rule rather than the exception. The intensity of the forces thus to be exerted on vulnerable cerebrospinal structures by the resulting pressure-gradients in the craniovertebral space is unknown. There is a need to consider the various conditions which may cause individual proneness to heavier reflux into particular cerebral as well as epi- and subdural spinal venous compartments. An attempt is made to indicate eventual consequences of excessive retrograde dilatation especially of internal cerebral veins. The importance of elucidating the neuropathological and clinical implications of undue reflux into the skull or spine is deduced from the probability of relations between localized backflow into the craniovertebral space and unexplicated cerebrospinal diseases. In this regard the features of multiple sclerosis are discussed.