Cerebral Edema after Laser Radiation

Abstract

Cerebral edema was studied with the electron microscope in rats around a focal area of cortical necrosis produced by LASER radiation. Swollen astrocytic processes without much enlargement of intercellular spaces were observed in the edematous cortex. In the white matter very wide extracellular spaces developed. Thorotrast, which was injected intravenously just prior to LASER radiation, escaped from disrupted vessels in the necrotic center of the lesion but did not traverse vessel walls in the edematous brain. Thorotrast spread from the area of necrosis into the surrounding edematous tissue. Narrow intercellular spaces in the edematous cortex limited but did not prevent the diffusion of Thorotrast particles. Glycogen accumulated within astrocytes in the edematous cortex, but not in the white matter.