Brain Edema: Types, Symptoms, Causes And Treatment

This cerebral accident appears when a liquid fills parts of the brain in which it is of more.

Brain edema

If someone tells us they have fluid retention, we are probably thinking of a person with inflamed and swollen legs or some part of the body. Said in this way, it may seem somewhat irrelevant, easily treatable and that can hardly be a nuisance, as in fact it is in many cases. However, this fluid retention or edema can be very dangerous depending on where it occurs. Because having fluid retention in the legs or ankles is not the same as having it in organs such as the lung.

One of the most serious and dangerous situations that can occur in this regard is the presence of cerebral edema, which can even be the cause of death.

Defining the concept of edema

Before talking about cerebral edema itself, it is necessary to first understand what we mean when we talk about the term edema. It is understood as such the existence of a swelling or inflammation of soft tissues due to the accumulation of fluid in or between its cells, due to imbalances in the amount of interstitial fluid that leaves or enters the cells.

This inflammation can have a wide variety of causes and can be found in almost all types of soft tissues in the body, and may have repercussions of different considerations depending on the type of tissue affected.

Brain edema: main symptoms

One of the locations where edema can occur, as well as one of the most dangerous, is in the brain tissue. In cerebral edema, we find an increase and accumulation of fluid between the brain cells that generates an inflammation of sufficient magnitude to cause clinical symptoms.

This inflammation is so serious in this case because the brain does not float in a vacuum, but is surrounded by a bony structure that protects it but in turn limits it: the skull. The accumulation of fluid can cause a compression of the brain mass against the walls of the brain, which can cause neurons to end up dying.

Likewise, it greatly increases the level of intracranial pressure by not maintaining the usual electrolyte balance, which can also alter and cause cell degeneration. Finally, compression can affect the blood vessels, preventing oxygen from reaching some of the brain regions and it ends up drowning.

Depending on the compressed brain regions, symptoms can vary greatly. Generally, dizziness, fatigue and weakness appear, as well as a possible alteration in the level of consciousness, headaches, gastrointestinal symptoms such as nausea and / or vomiting or perceptual disturbances. Breathing may accelerate and seizures may even appear.

Related to alterations in consciousness, in severe cases the patient’s coma or even death can be caused if the nuclei responsible for maintaining the heart and respiratory rhythm are compressed. In some cases it can lead to a herniation of the brain or the permanent loss of relevant functions.

In addition to these symptoms, the presence of cerebral edema can lead to death or the appearance of some type of physical, mental or sensory disability, which can greatly alter the normal functioning of the person, either temporarily or permanently.

Types of brain edema

There is no single type of cerebral edema, but we can find different types depending on where and why the imbalance and fluid accumulation occurs. And is that the liquid can accumulate both within cells and in the extracellular space.

1. Cytotoxic edema

In this type of edema, the swelling occurs when fluid accumulates within the cells themselves, having abnormally captured an excessive amount of interstitial fluid. It is generally produced by a malfunction of the sodium / potassium pumps and the channels through which fluid enters and leaves the cells. We are faced with a problem of regulation of cellular metabolism and the maintenance of homeostasis. The consumption of some toxic element can be one of its causes.

2. Vasogenic edema

Edema that occurs as a result of increased permeability of the nervous system, due to the breakdown of the blood-brain barrier, is considered as such. Generally we find that the blood plasma penetrates into the parenchyma or extracellular space that surrounds the nerve cells and accumulates in it. It is the most common type of brain edema. Tumors, strokes, and head injuries tend to be some of its most common causes.

3. Hydrocephalic or interstitial edema

Edema generated by the obstruction of the channels through which the cerebrospinal fluid circulates, causing the cerebral ventricles or the areas near the blocked area to become inflamed. It appears in hydrocephalus.

Possible causes

There are a large number of possible causes for the existence of cerebral edema. Some of the most frequent are the following.

1. Head injury

One of the causes that can be easier to identify is the one that has to do with the existence of a trauma to the head. This blow causes the breakage of blood vessels to occur, flooding the brain with blood. When trying to absorb the excess fluid, the cells would become inflamed.

2. Stroke

The existence of a cerebral hemorrhage or blockage of the cerebrovascular system is one of the best known causes of cerebral edema. And it is that these accidents would generate either that fluids were directly extravasated inside the brain or that the nerve cells would die and break, causing an accumulation of fluid.

3. Viral or bacterial infections

Another possible cause of cerebral edema can be found in the existence of an infection. Cells are damaged and ruptured, their remains generating an imbalance in the level of brain fluid. Within this group of causes we find very different diseases, from meningitis to Reye’s syndrome.

4. Tumors

The appearance of neoplasms, be they benign or malignant, can cause compression of the blood vessels or block the passage of cerebrospinal fluid, which can lead to the appearance of fluid accumulation in some areas of the brain.

5. Hypoxia derived from altitude

This type of edema occurs in subjects such as climbers and divers. The main cause is the existence of a sudden variation in atmospheric pressure in the face of a rapid rise : in the absence of oxygen the body tries to dilate the arteries and veins of the nervous system, but if this situation is prolonged or the change is generated very quickly said Dilation will generate homeostatic difficulties that will culminate in the accumulation of fluids in the brain.

6. Hyponatremia

Disorder that occurs in the absence of a sufficient level of sodium in the blood, which the body tries to compensate by causing an increase in the entry of fluid into the cells.

7. Intoxication

The consumption of a poison or poisoning can generate alterations in the nervous system that cause the existence of imbalances in the levels of intra or extracellular fluid.


The treatment of cerebral edema is essential and requires rapid professional action in order to avoid death or the appearance of irreparable damage to the patient.

The first step that should be used is the elimination of the accumulation of fluid and the reduction of inflammation, being essential to monitor vital signs at all times. Artificial respiration mechanisms may be necessary to maintain a constant and sufficient flow of oxygen.

In cases where the patient’s life is in danger, surgery is usually used immediately to control the level of inflammation by draining the fluid, or resection of part of the skull to relieve and reduce intracranial pressure. Once the patient is stabilized, it is necessary to analyze what has generated the problem in order to treat its causes.

Likewise, it has been proven that the induction of controlled hyperventilation reduces the formation of cerebral edema. However, it must be very controlled, since depending on how much and for how long it is carried out, it can have very harmful effects.

Both in this and in other cases in which surgery is not used, the use of different drugs is common. For example, the application of corticosteroids is very frequent in order to reduce the level of intracranial pressure in those cases in which the problem is not of cytotoxic or hemorrhagic origin. Osmotics and diuretics can also be used to facilitate the expulsion of liquids.

Bibliographic references:

  • Cecil, R. (2015). Cecil medicine (24rd ed.). Philadelphia, Philadelphia: Saunders Elsevier.
  • Jaramillo, JJ (1997). Fluid management in the neurosurgical and head trauma patient. Memories XXIII, Annual update course in Anesthesiology. Mexican Society of Anesthesiology.
  • Jha, SK (2003). Cerebral edema and its management. Medical Journal Armed Forces India, 59 (4), 326-331.
  • Kasper, D. (2015). Harrison’s principles of internal medicine (19th ed.). New York, New York: McGraw-Hill, Medical Pub. Division.
  • Milhorat, TH; Johnson, WD; Dow-Edwards, DL (1989). Relationship between edema, blood pressure, and blood flow following local brain injury. Neurol. Res.; 11:29
  • Renkin, EM (1994) Cellular aspects of transvascular exchange: a 40-year perspective. Microcirculation 1 (3): 157–67.

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