Measurement of intracranial pressure in the unanesthetized rabbit

A method is described for the measurement of intracranial pressure in the unanesthetized, minimally restrained rabbit utilizing a modified subarachnoid screw system. The pressures are transmitted from within the cranium via a flexible saline filled catheter to a fixed external pressure transducer. An index of the relative vertical position of the animal's skull as compared to the fixed transducer is given by means of a second open-ended pressure measuring catheter, the open end of which is fixed to the subarachnoid screw assembly on the animal's skull. The system was found to be a reliable method of measurement of intracranial pressures in the minimally restrained rabbit, and could easily be adapted to other animal species. The method is currently being used to assess the effects of fever on intracranial pressures.