Abstract

Impedographic studies were made in cats made hydrocephalic by intracisternal kaolin. Enlargement of the anterior horns preceded that of the body of the lateral ventricles, and there was a selectivity to pressure atrophy among different tissues within the brain. Furthermore, sequential measurement of impedance using chronically implanted electrodes demonstrated a gradual decrease of impedance in the periventricular white matter during the development of hydrocephalus, suggesting an expansion of the extracellular space in the tissue around the ventricular wall.