brain edema: types, symptoms, causes and treatment

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

One of the most serious and dangerous situations that can arise in this regard is the presence of brain edema, which can even lead to death.

    Define the concept of edema

    Before we talk about brain edema itself, we first need to understand what we are referring to when we talk about the term edema. It is understood as such the existence of soft tissue inflammation due to the accumulation of fluid in or between their cells, due to imbalances in the amount of interstitial fluid leaving or entering the cells.

    This inflammation can have a wide variety of causes and can be localized in almost any type of soft tissue in the body, and can impact different considerations depending on the type of tissue affected.

      Brain edema: main symptoms

      One of the places 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 which generates inflammation of sufficient magnitude to cause clinical symptoms.

      This inflammation is so severe in this case because the brain does not float in a vacuum., But is surrounded by a bone structure that protects it but in turn limits it: the skull. The buildup of fluid can cause the brain mass to compress against the walls of the brain, which can cause neurons to die.

      Likewise, dramatically increases intracranial pressure level by not maintaining the usual electrolyte balance, which can also alter and cause cell degeneration. Finally, the compression can affect the blood vessels, preventing oxygen from reaching any area of ​​the brain and drowning.

      Depending on the areas of the brain that are compressed, the symptoms can vary widely. Dizziness, fatigue and weakness usually appear, as well as possible altered level of consciousness, headache, gastrointestinal symptoms such as nausea and / or vomiting or disturbances in perception. Breathing may speed up and seizures may even occur.

      Linked to alterations in consciousness, in severe cases, it can cause the patient to coma or even death if the nuclei responsible for maintaining the heart and respiratory rate are compressed. In some cases, this can lead to a brain hernia or the permanent loss of relevant functions.

      In addition to these symptoms, the presence of brain edema can lead to death or the onset of some type of physical, mental or sensory disability, Being able to modify to a large extent the normal functioning of the person is temporary or permanent.

      Types of brain edema

      There is no one type of brain edema, But we can find different types depending on where and the reason why the imbalance and the fluid build-up occurs. And it is that the liquid can accumulate as much inside the cells as in the extracellular space.

      1. Cytotoxic edema

      In this type of edema, the swelling occurs when fluid builds up inside the cells themselves, having captured these abnormally excessive amounts of interstitial fluid. It is usually caused by a malfunction of the sodium / potassium pumps and the channels through which fluid enters and leaves cells. We are faced with a problem of regulating cell metabolism and maintaining homeostasis. The consumption of certain toxic elements can be one of the causes.

      2. vasogenic edema

      It is considered as such an edema that occurs as a result of an increase in the permeability of the nervous system, due to the breakdown of the blood-brain barrier. It is generally found that blood plasma enters the parenchyma or extracellular space that surrounds and accumulates in nerve cells. This is the most common type of brain edema. Tumors, strokes, and head trauma are among the most common causes.

        3.hydrocephalic or interstitial edema

        Edema caused by blockage of the ducts through which cerebrospinal fluid circulates, causing inflammation of the brain ventricles or areas near the blocked area. It appears in hydrocephalus.

          Possible causes

          There are many possible causes for the existence of brain edema. Some of the most common are as follows.

          1. Cranioencephalic trauma

          One of the easiest causes to identify is that it is a head injury. This blow causes the blood vessels to rupture, Flood the brain with blood. While trying to absorb the excess fluid, the cells would become inflamed.

          2. Stroke

          One of the most well-known causes of cerebral edema is the existence of a brain hemorrhage or a blockage of the cerebrovascular system. And it is that these accidents would generate that either fluids will be extravasated directly inside the brain, or that the nerve cells will die and break, causing an accumulation of fluid.

          3. Viral or bacterial infections

          Another possible cause of brain edema can be found in the existence of an infection. The cells are damaged and break down, causing their remains to imbalance the level of brain fluid. In this group of causes we find very different diseases, from meningitis to Reye’s syndrome.

            4. Tumors

            The appearance of neoplasms, whether benign or malignantIt can cause compression of the blood vessels or block the passage of cerebrospinal fluid, which can result in the appearance of fluid accumulation in certain areas of the brain.

            5. Hypoxia derived from altitude

            This type of edema occurs in people such as climbers and divers. The main cause is the existence of a sudden change 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 continues or if the change is generated very quickly this dilation will generate homeostatic difficulties which will lead to the accumulation of fluid in the brain.

            6. Hyponatremia

            A condition that occurs when there are not enough sodium levels in the blood, which the body tries to compensate for by causing more fluid to enter cells.

            7. Poisoning

            Consumption of a poison or poisoning it can generate alterations in the nervous system which cause the existence of imbalances in the levels of intra or extracellular fluid.


            Treatment of cerebral edema is essential and requires prompt professional action in order to avoid death or the onset of irreparable damage to the patient.

            The first step to take is to remove fluid buildup and reduce inflammation, and it is essential to monitor vital signs at all times. Application of artificial respiration mechanisms may be necessary to maintain a constant and sufficient oxygen flow.

            In cases where the patient’s life is in danger, it is common to immediately resort to surgery to control the level of inflammation by draining the fluid or resecting part of the skull. by release and reduce intracranial pressure. Once the patient is stabilized, it is necessary to analyze what caused the problem in order to treat its causes.

            It has also been proven that induction of controlled hyperventilation decreases the formation of cerebral edema. However, it must be very controlled, because depending on the extent and duration of its execution, it can have very harmful effects.

            In this and other cases where surgery is not used, it is common to use different drugs. For example, the application of corticosteroids is very common in order to reduce the level of intracranial pressure in cases where the problem is not of cytotoxic or hemorrhagic origin. You can also use osmotics and diuretics to help expel fluids.

            Bibliographical references:

            • Cecil, R. (2015). Medicine Cecil (24th ed.). Philadelphia, Philadelphia: Saunders Elsevier.
            • Jaramillo, JJ (1997). Fluid management in the neurosurgical patient with traumatic brain injury. Reports XXIII, Annual Refresher Course in Anesthesiology. Mexican Society of Anesthesiology.
            • Jha, SK (2003). Brain edema and its management. Armed Forces of India Medical Journal, 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 circulation after local brain injury. Neurol. Nothing.; 11:29
            • Renkin, EM (1994) Cellular aspects of transvascular exchange: a 40-year perspective. Microcirculation 1 (3): 157-67.

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