Fig. 1.

Illustration of the ICP-volume curve and its relationship to the intracranial pulsatility parameters. Under normal physiological conditions with high intracranial compliance, the ICP wave amplitude is correspondingly small. As intracranial compliance decreases (steep part of the pressure-volume curve), the brain behaves increasingly like a linear elastance and so variations in intracranial volume correlate increasingly well with changes in mean ICP, the steepness of the pressure-volume curve also accounts for large-amplitude ICP waveforms.