Continuous intraventricular cerebrospinal fluid pressure recording in normal rabbits during wakefulness and sleep

Twenty-five conscious rabbits that had a ventriculostomy performed with implantation of an intraventricular cannula into the lateral ventricle were put into a controlled climate chamber. Continuous recording of intraventricular cerebrospinal fluid pressure (VFP) was performed during wakefulness and sleep. Spontaneous episodic increases in VPF during desynchronized sleep were found. The mean VFP rose about 10 ± 0.6 mmHg above the VFP levels of the other state of sleep. The episodes occurred 12 ± 3 times during the night (10:00 PM - 8:00 AM) and lasted for 4.4 ± 1.0 minutes. The duration and amplitude of these waves are different from either Lundberg's A waves or Lundberg's B waves. This wave pattern of increased VFP is a feature of normal intracranial pressure.