Parametric changes in an intracranial pressure model during plateau waves.

Abstract

The intracranial pressure (ICP) is commonly monitored in patients with head trauma. A sudden rise in the ICP to an elevated level, i.e., the occurrence of a plateau wave in the ICP, often indicates the worsening of the patient's condition. Several clinical symptoms usually accompany a plateau wave, but the physiological causes for the elevated ICP are difficult to specify. In this study, a mathematical model representing the ICP dynamics is used to study possible physiological changes in the dynamics of the cerebrospinal fluid (CSF) flow, which could result in the appearance of plateau waves. The effects of changes in the CSF absorption resistance (R), in the dural venous sinus pressure (Pd), and in the mean CSF formation rate (If) on the ICP are determined by simulating the mathematical model. Simulation results indicate that plateau waves in the ICP can be produced by the aforementioned changes under certain conditions. Using a recursive parameter estimation algorithm, the mean ICP (P) and the normalized CSF absorption resistance (RO) can be tracked with time. The analysis of clinically recorded ICP data shows that the value of R0 increases during a plateau wave. Simulation results are then discussed and critically viewed.