Fluid dynamics of cerebrospinal venous flow in multiple sclerosis.

Stenotic immobile valves and other malformations obstruct normal cerebrospinal venous outflow, resulting in reflux flow which combines with the normal outflow to produce standing pressure waves in the internal jugular and other cerebrospinal veins. It is hypothesized that, if the cerebrospinal venous structure between the obstruction and the deep cerebral veins is sufficiently non-compliant, the standing wave will result in bidirectional flow in the fine cerebral veins. Bidirectional flow in the fine veins, over extended periods of time, will cause disorder in the veins' endothelial morphology, and ultimately, result in the disruption of the blood-brain barrier as observed in multiple sclerosis. This physics-based analysis demonstrates a positive correlation between clinically observed MS attributes with the predicted flow patterns and venous malformations that are based on fluid dynamics principles that include venous compliance influences. The physics-based approach used in this analysis provides new insights into MS pathologies based on predicted pressure and flow patterns.