A model of the dynamics of intracranial pressure during conditions of intact and loss of cerebral vascular tone

A mathematical model has been developed to simulate the dynamics of intracranial pressure and cerebral blood flow. This model is based on the hypothesis that during the condition of normal vascular tone a major component of venous blood flow into the superior sagittal sinus is reduced during positive pressure inhalation. In contrast, during loss of vascular tone and massive vasodilation, venous blood flow is not markedly reduced during positive pressure inhalation. A non-linear resistance was used to simulate the pressure dependent behavior of both the resistance of bridging veins into the lateral lacuna and resistance of elements of chordae Willisii along the walls of the sagittal sinus. All parameters of the model were obtained from previously published values or direct calculation using available physiological data and analog simulation. A comparison between the experimentally recorded and simulated intracranial pressure signals demonstrates the possible validity of the model.