An integrative approach to intracranial hydraulic physiology. I. Basic concepts, pressure-volume relationships, and infusion studies.

A computer simulation of the anatomy of the intradural fluid compartment is used to explore intracranial hydraulic physiology. It examines the mutual interactions of fluid flow rates, volumes, and pressures that control the physiology of the intracranial fluid. The mechanisms of change in intracranial pressure despite the fixed volume constraint are elucidated. The physical origins of the pressure-volume curve and data on the infusion of cerebrospinal fluid are examined. The dynamic behavior of this passive system closely simulates the observed physiologic response to bolus infusion, constant rate infusion, hypercapnia- hypocapnea , and hydrocephalus.