Cerebral edema: causes, symptoms, effects

Cerebral edema is a nonspecific pathological increase in the volume of brain tissue due to an increase in the content of fluid in it. It is not an independent disease and arises from various pathological conditions of exogenous or endogenous nature. Cerebral edema refers to potentially life-threatening complications, which is explained by the risk of critical squeezing of nerve structures in natural openings or protrusions of the skull.

Etiology

Cerebral edema can be a consequence of nerve cell damage or severe metabolic disorders. Its main reasons include:

• open and closed brain trauma, including surgery;
• infectious diseases, leading to a toxic or direct (with neuroinfections) damage to the nervous tissue;
• brain tumors causing displacement of brain structures or disturbance of cerebrospinal fluid outflow;
• embolism of cerebral vessels with the development of ischemic stroke, as an embolus may act thrombi, crumbled atherosclerotic plaques, gas bubbles;
instagram viewer
• hemorrhagic stroke, subarachnoid hemorrhage;
• poisoning with neurotoxic poisons and some drugs;
• eclampsia;
• radiation exposure;
• metabolic encephalopathy, the most frequent causes of its development are renal-hepatic insufficiency, diabetes mellitus, alcoholism;
• water intoxication, condition after drowning in fresh water.

In children born prematurely or as a result of pathological births, the edema of the brain is mainly traumatic.

Toxic brain swelling can be caused by exposure to phenols, alcohols, acetone, gasoline (and other refined products), organophosphorus compounds, cyanides, turpentine and a number of other substances. Of drugs, neurotoxic effects in overdose have neuroleptics, tranquilizers, tricyclic antidepressants, atropine, quinine derivatives, antihistamines. Some drugs initially lead to cardiovascular disorders, which affects the functioning of the brain and thus contributes to the development of its edema.

Pathogenesis

With edema of the brain, excess fluid can accumulate in the intercellular space or in the cytoplasm of neurons. In the latter case, they speak of swelling of the brain tissue. Both these states lead to an increase in brain volume and disruption of its functioning and are usually combined with each other.

Currently, there are 4 main mechanisms of cerebral edema development: vasogenic, cytotoxic, osmotic, hydrostatic. Their formation depends on the cause of the defeat of the nervous tissue. With the progression of puffiness to the primary pathogenetic mechanism, others are beginning to be connected, which aggravates the existing disorders. Any form of brain edema leads to an increase in intracranial pressure due to a reduction in the space between the soft and dura mater.

Vasogenic edema occurs due to increased permeability of the walls of the capillaries and a prolonged increase in pressure inside the cerebral vessels. This contributes to the growth of plasma filtration, disruption of the blood-brain barrier and the subsequent spread of fluid through the intercellular spaces. Vasogenous edema is more pronounced in white matter of the brain, which, compared with the bark, is more friable in structure.

The osmotic mechanism of edema often accompanies the vasogenic, it is caused by a pathological osmotic gradient between the plasma and the intercellular fluid. Hyperosmolarity of the brain tissue is noted with decompensated metabolic encephalopathy, renal and hepatic insufficiency, hyperglycemia.

Cytotoxic edema is the intracellular accumulation of fluid due to disruption of the operation of ion pumps of cell membranes in conditions of deficiency of ATP. It is this mechanism that leads to the swelling of the brain. Primary glial cells are affected, then the process captures the bodies of neurons.

Hydrostatic edema of the brain is caused by a rapid excess pressure increase in the ventricular system of the brain. Most often this is caused by a significant violation of the outflow of cerebrospinal fluid while maintaining its production.

Symptoms

Headache caused by cerebral edema, worn out the patient and is not removed by taking analgesics.

Symptomatic of cerebral edema consists of manifestations of increased intracranial pressure and local neurological disorders due to the compression of certain brain structures.

The main symptoms are:

• not stopping with the use of analgesics bursting, pressing, diffuse headache;
• a feeling of pressure on the eyeballs and ears, impaired vision and hearing;
• vomiting, not associated with food intake and not bringing relief;
• a change in the depth of consciousness, because of what a person looks confused, slowed down, indistinctly oriented in time space, with the growth of edema consistently develops sopor and coma;
• short-term episodes of loss of consciousness are not excluded;
• it is possible to develop convulsive syndrome, which is most often associated with irritation of the motor cortex of the cerebral cortex;
• diffuse muscle hypotension;
• appearance and growth of focal neurological symptoms, pathological stem reflexes;
• psychotic disorders, the most typical visual hallucinosis and psychomotor arousal against the background of confusion.

The addition of new symptoms, a progressive decrease in the level of consciousness indicate an aggravation of cerebral edema. This is life-threatening condition and requires intensive therapy with elimination of the cause and correction of metabolic disorders.

Than the edema of a brain is dangerous

The most formidable complication of cerebral edema is the development of a dislocation syndrome. Lateral or axial displacement of the brain structures leads to their inoculation into the large occipital foramen or under the outgrowths of the dura mater (under the cerebellar nest or crescent process). In this case, there is an infringement of various parts of the cerebellum, brainstem, medial divisions of the parietal and frontal lobes, basal parts of the temporal lobe.

The most formidable signs of dislocation syndrome are a violation of the rhythm of breathing and palpitation, a significant persistent decline blood pressure, floating movements of eyeballs, bulbar disorders and rough pyramidal insufficiency. And the development of occlusive crises leads to the arrest of cardiac and respiratory activity.

The long-term consequences of a severe cerebral edema can be cognitive disorders and preserved neurological symptoms.

Research Institute of Neurosurgery. N. N. Burdenko, video presentation on the topic "Variations of cerebral edema":

Edema of the brain

Watch this video on YouTube