A mathematical study of human intracranial hydrodynamics. Part 2--Simulation of clinical tests.

The mathematical model of human intracranial hydrodynamics proposed in a previous paper is here used to simulate the results of some dynamical tests of great clinical and physiological value and to analyze the blood flow pattern in the intracranial human basal arteries (especially in the internal carotid artery). Peak to peak amplitude of the blood flow waveform in the intracranial basal arteries, computed through the model, shows a significant increase at intracranial pressure levels above 50-60 mmHg, in accordance with recent experimental data. Moreover, diastolic blood flow appears to be largely sensitive to intracranial pressure changes during severe intracranial hypertension, whereas systolic blood flow is only slightly affected in this condition. The response of intracranial pressure to typical saline injection (volume-pressure response, steady state infusion and bolus injection tests) and to an abrupt obstruction in the extracranial venous drainage pathway is also well reproduced by the model. Finally, alterations in these responses, due to changes in some significant intracranial hydrodynamical parameters (i.e., the intracranial elastance coefficient and CSF outflow resistance) are presented.