Cerebral Oedema
The term cerebral edema denotes an increase in the water content of brain and it will leads to brain volume expansion.
Cerebral edema can occur either focally or diffusely and this can be seen after any type of primary injury to the brain and in some systemic medical conditions, example acute or acute-on-chronic liver failure.
Vasogenic Oedema
Vasogenic cerebral edema is due to the dysfunction of the blood-brain barrier,
There is a physical and metabolic barrier between the systemic circulation and brain and it is formed by endothelial cells, the tight junctions between endothelial cells, astrocytes, and pericytes.
Blood-brain barrier dysfunction leads to extravasation of ions and macromolecules from the plasma; these ions and macromolecules generate an osmotic pressure, which, combined with vascular hydrostatic pressure, results in net movement of water into the brain.
The resulting water expands the extracellular space and it is collected mainly in the subcortical white matter, and this will spare the cortical and deep gray matter.
What are the conditions you get Vasogenic cerebral oedema?
Vasogenic edema is typically seen with brain tumors, cerebral abscesses, and posterior reversible encephalopathy syndrome (PRES).
Recent literature have shown that for producing vasogenic edema frank blood-brain barrier disruption visible on microscopy is not necessary. As this can be contributed by abnormal transcellular transport across endothelial cells and degradation of endothelial tight junctions by proteolytic enzymes, such as matrix metalloproteinase-9.
