An effective model of cerebrovascular pressure reactivity and blood flow autoregulation

•A lumped-parameter model of cerebral blood flow autoregulation is developed.•The model quantifies the effectiveness of myogenic pressure-reactivity and its limitations.•The model explains pressure bounds outside of which autoregulation loses effectiveness.•The model demonstrates how inertial and resistance factors degrade the autoregulatory performance.•By including the buckling of vessels, the model shows that the collapse of vessels obstructs the myogenic dilation in the hypotensive regime.

Understanding cerebral blood flow dynamics is crucial for the care of patients at risk of poor cerebral perfusion. We describe an effective model of cerebral hemodynamics designed to reveal important macroscopic features of cerebral blood flow without having to resolve the detailed microvasculature of the brain. Based on principles of fluid and elastic dynamics and vascular pressure-reactivity, the model quantifies the physical means by which the vasculature executes autoregulatory reflexes. We demonstrate that the frequency response of the proposed model matches experimental measurements and explains the influence of mechanical factors on the autoregulatory performance. Analysis of the model indicates the existence of an optimal mean arterial pressure which minimizes the sensitivity of the flow to changes in perfusion pressure across the frequency spectrum of physiological oscillations. We highlight the simplicity of the model and its potential to improve monitoring of brain perfusion via real-time computational simulations of cerebro- and cardio-vascular interventions.