Pulsatile cerebrospinal model with cardio-vascular coupling

Abstract

In this paper we describe a model of the human intracranial space which is extended with the vascular system. We focus on a detailed modelling of the coupling between cerebral vessels and intracranial pressure (ICP). On the one hand, the model is based on a linearisation of the Navier-Stokes equation for the blood vessels and a subsequent geometric discretisation, leading to a distributed parameter approach of coupled ordinary differential equations. On the other hand, a concentrated parameter modelling approach is developed for the intracranial space which is subsequently extended by a production and resorption circuit for the craniospinal fluid. The intention of the model is to describe the transmission of pulsatile blood pressure waves from the cerebral vessels to the ICP, as it can be observed from clinical continuous intracranial pressure measurements. A good agreement of pulsatile ICP is shown in an in-silico study, compared to clinical continuous ICP measurements. An analysis of vascular impedance under variable intracranial compliance and for a non-symmetric Circle-of-Willis completes this study.