On the intracranial pressure-volume curve.

The intracranial pressure-volume curve is considered and a new mathematical model proposed to describe it. Researchers and clinicians currently use an exponential curve to describe the increase in intracranial pressure following a rapid increase in the fluid volume in the cranial vault. It is argued in this paper that a form of logarithmic curve, derived from elementary physical principles, can also be used. An upper limit to the extra volume is an intrinsic feature of the model and the argument does not require a variable compliance to be associated with the system.