Cerebral edema is an abnormal accumulation of fluid in the cerebral tissue, intercellularly and intracellularly in astrocytes.
The causes of cerebral edema are very varied : they can result from a mechanical cause (cerebral trauma), a metabolic disorder (accumulations of toxic derivatives) but also following a cardiovascular accident, secondary to cerebral hemorrhages, tumors, allergy, sepsis or hypoxia.
Liver diseases, acute and chronic, are also a cause of edema.
There are several types of cerebral edema : vasogenic, cytotoxic, osmotic and interstitial.
- Vasogenic cerebral edema is due to the rupture of tight junctions of the cell membranes of the blood-brain barrier. This rupture results in plasma and protein penetration into the brain tissue. This type of edema is observed in case of acute liver disease.
- In case of cytotoxic cerebral edema, the blood-brain barrier remains intact. This edema is the result of an alteration in the functioning of the sodium/potassium pumps of the membrane of the glial cells causing water and sodium retention. Many other causes (others pumps/transporters, increase of cerebral solutes) could lead to osmotic desquilibrium. This results in the hypertrophy of astrocytes (“astrocyte’s swelling”). This type of edema is observed in case of chronic liver disease.
- In osmotic cerebral edema, a difference in osmotic gradient is established between the cerebro-spinal fluid and the extracellular fluid of the brain with plasma that promotes fluid entry into the brain.
- Interstitial cerebral edema is caused by rupture of the meningoencephalic barrier, which induces entry of cerebrospinal fluid (protein-free) into the extracellular space and the white matter.
Depending on the severity of the edema, the underlying symptoms may be more or less severe. The pressure of the cranial box on the cerebral tissues causes a compression of the veins, arteries and nerves. This intracranial hypertension has an effect on the cerebral perfusion resulting in local necrosis and ischemia (decreased oxygen intake).
Symptoms may vary from walking, speech, dizziness, dizziness, vomiting, visual impairment, vigilance or loss of knowledge.
The diagnosis is done by scanning or magnetic resonance imaging (MRI) (allows to visualize the size of an anomaly in the brain tissue).
The treatment of cerebral edema is drug-based corticosteroids with monitoring of intracranial pressure for treatment adaptation. The objective of the treatment is to eliminate excess fluid and decrease the intracranial pressure. Depending on the cause of cerebral edema, it is possible to envisage surgical treatment by setting up a bypass (shunt) in order to draining excess fluid.