Cerebrospinal fluid pulse pressure and brain compliance in adult cats.

Cerebrospinal fluid (CSF) pulse pressure was inversely proportional to a brain compliance determined from artificial CSF pulsations generated by an external pump. Brain compliance was 0.71 cu mm/mm H2O at steady-state CSF mean pressure and decreased 50 percent for each 240 mm H2O increase in CSF mean pressure (mean results of duplicate experiments on 10 adult cats). Both CSF pulse pressure and the time course of transient changes in CSF mean pressure could be described in terms of a model of the CSF circulation consisting of a constant resistance to CSF absorption in parallel with a pressure-dependent brain compliance.