Cerebral edema is defined as an abnormal retention of water in brain tissue, resulting in an increase in brain tissue volume.In 1967, Klatzo classified cerebral edema into vasogenic cerebral edema and cytotoxic cerebral edema depending on its cause and pathology. Vascular-derived cerebral edema is an increase in capillary wall permeability leading to leakage of plasma proteins, water, and dielectrics outside the vessels, which enlarges the extracellular lumen of the white matter portion. In 1975, Fishman added a third type, interstitial edema, because hydrocephalus stretches the ventricular wall, breaks the ventricular epithelium, and infiltrates the cerebrospinal fluid spongiously into the periventricular white matter extracellular space. This classification is simple and easy to understand, but in the case of brain tissue lesions, it is almost always mixed hydrocephalus.
Classification of cerebral edema
Cytotoxic
vascular-derived
Interstitial
Site of damage
Brain cells
Capillary endothelium
Cerebrospinal fluid circulation
Site of occurrence
Intracellular, gray or white matter
Extracellular, mainly in the white matter
Extracellular, periventricular white matter
Mechanism of occurrence
Impaired cellular metabolism
Increased capillary permeability, disruption of blood-brain barrier
Increased cerebrospinal fluid pressure
Retained fluid properties
Water and sodium (plasma ultrafiltrate)
Plasma proteins (plasma filtration)
Cerebrospinal fluid
Ultrastructural changes
Swelling of brain cells, shrinking of extracellular lumen
Increased swallowing vesicles of endothelial cells, enlarged tight junctions, enlarged extracellular lumen
Enlargement of extracellular spaces around the ventricles
Underlying disorders
Water intoxication, hypoxemia, ischemia, bacterial meningitis
tumor, hemorrhage, ischemia, abscess, lead poisoning, bacterial meningitis
obstructive hydrocephalus, benign intracranial pressure increase, bacterial meningitis