Electron Microscopic Observations on Human Brain Edema Studied in Biopsy Material

Abstract

Some years ago, I studied biopsies of human brain edema. Samples were obtained during surgical operations for tumors, abscesses or hematomas, after putting some drops of cold osmic acid in situ on the adjacent white matter. This process is not dangerous since the periventricular gray matter is at quite a large distance and the osmic acid is hardly penetrating. Samples were then taken of perifocal edema in the later stages. They were taken far from the edematous focus and we may have missed the most typical lesions of the blood-brain barrier. Samples were said to have been taken from the centrum ovale; it is possible that some of them were taken either deeper than I thought or from the arcuate fibers by perforation of a convolution. As in cortical edema samples, the most typical lesion was the swelling of astroglia as well as of oligodendroglia (Fig. 1).