Modeling of intracranial hemodynamics and cerebral venous outflow: Pressures and flows behavior under arterial pulse simulation

摘要

Cerebral hemodynamics in humans is affected by postural changes (variations of the brain-axis direction with respect to the gravity field) and alterations of the basal hydraulic conductances in the main extracranial vasculature (jugular stenosis). The combined action of these factors can affect basal pressures and flows at any point of the cardiovascular system, potentially leading to different short and long-term diseases. To study this complex system, a mathematical model for the simulation of the cerebral circulation and brain drainage was developed. It takes into account the intracranial autoregulation mechanisms, the collapsibility of internal jugular veins and the time dependence of the arterial pressure due to the left ventricle. The model parameters are tuned in order to properly reproduce supine and upright flow data (obtained with Magnetic Resonance and Echo-Color Doppler technique) from healthy people and subjects with a specific stenotic pattern. First simulations show how the arterial pressure pulse affects the behavior of flows and pressures over time, and how these variables depend on different setting of parameters (i.e. simulation of different posture and stenotic pattern).