Figure 14-26.

Types of Cerebral Edema.

A, Normal blood-brain barrier. Endothelial cells are red; astrocytes are beige; neurons are light yellow. B, Cytotoxic edema. Cytotoxic edema is characterized by the accumulation of fluid intracellularly (in neurons, astrocytes, oligodendroglia, and endothelial cells) as a result of altered cellular metabolism, often caused by ischemia. The gray and white matter are both affected. The fluid taken up by swollen cells is primarily derived from the extracellular space, which becomes reduced in size and has an increased concentration of extracellular solutes. C, Vasogenic edema. This type of edema is seen in acute inflammation, and its basic mechanism is an increase in vascular permeability from the breakdown of the blood-brain barrier. This breakdown allows movement of plasma constituents such as water, ions, and plasma proteins into the extracellular space, particularly that of the white matter.

(Courtesy Dr. J.F. Zachary, College of Veterinary Medicine, University of Illinois. Redrawn and modified from an illustration from Leech RW, Shuman RM: Neuropathology: a summary for students, Philadelphia, 1982, Harper & Row.)