[Measurement of ventricular fluid pressure and brain tissue pressure in acute experimental communicating hydrocephalus (author's transl)].

Malabsorption of cerebrospinal fluid was made experimentally by the administration of neutral carbon black suspension into the lateral ventricles of 22 adult cats. The compartmental analysis of intracranial pressure at the intraventricular fluid and tissue pressure in the cerebral white matter was carried out in the early stage of the communicating hydrocephalus. Following results were obtained: 1) Cerebrospinal fluid pressure from the lateral ventricle was always significantly higher than that from the brain tissue during the process of ventricular expansion. 2) Water content in the cerebral white matter was correspondingly increased when the pressure difference with greater value in ventricular fluid pressure was maintained. However tissue water content was decreased definitively when such pressure values at two compartments were equalized due to augment of the tissue pressure component. 3) Decreasing of cerebral blood flow demonstrated in spite of relatively higher value of cerebral perfusion pressure. From these findings the authors speculated that a higher pressure in the ventricular system will be a driving force, by which the enlargement of ventricular system was induced.