What is cerebral edema?
Cerebral edema (also spelled as oedema, depending on the dialect) is swelling of the brain caused by the accumulation of excess fluid within the brain tissue. This is different from hydrocephalus, which involves an increase in cerebrospinal fluid or CSF within the ventricles.
What are the types of cerebral edema?
There are two types of cerebral edema: vasogenic edema and cytotoxic edema. The brain softens when it is swollen and the ventricles often shrink, the gyri (or ridges in the brain) are flattened and the sulci (grooves of the brain) are narrowed.
Vasogenic edema happens when the blood-brain barrier is disrupted for whatever reason. Because of the increased gap, fluid is able to shift from the other parts of the body into the blood vessels surrounding the brain. Vasogenic edemas can be either localised or generalised. In localised cases, tumours or abnormal permeability of vessels adjacent to inflammation are responsible.
Cytotoxic edema happens as a result of an increase of intracellular fluid due to injury of endothelial, glial or neuronal cells. These cells may be injured as a result of exposure to toxins, hypoxia (lack of oxygen) or as a ischaemic insult.