edema

(redirected from Brain edema)
Also found in: Dictionary, Thesaurus, Medical.
Related to Brain edema: encephalitis

edema

(ĭdē`mə), abnormal accumulation of fluid in the body tissues or in the body cavities causing swelling or distention of the affected parts. Edema of the ankles and lower legs (in ambulatory patients) is characteristic of congestive heart failure, but it can accompany other conditions, including obesity, diseased leg veins, kidney disease, cirrhosis of the liver, anemia, and severe malnutrition. Edema is the result of venous ulceration, which is often caused by an increase in tissue pressure (increased fluid within the tissue) because of increased capillary permeability. A failing heart is often accompanied by edema because the blood backs up into the veins, venules, and capillaries, thereby increasing blood pressure. In severe cases of heart failure, the abdomen may fill with fluid; this condition is called ascities. Appendage edema is often treated by bandaging the area to relieve pressure on the skin and decrease venous pressure. More severe cases may require a surgical procedure that diverts the blood flow to healthy veins. The accumulation of fluid within the lungs is a serious complication of cardiac failure, pneumonia, and other disorders. The collection of fluid in the pleural space (within the two-layered membrane surrounding the lungs) can be the symptom of numerous infectious and circulatory disorders. Lymphatic obstructions may result from various surgical procedures or from certain parasitic infections. These blockages cause increased back pressure in the lymph vessels and interfere with movement of fluid from interstitial tissue into venule ends of capillaries. The resulting collection of water within the skull is a serious and usually incurable condition (see hydrocephalushydrocephalus
, also known as water on the brain, developmental (congenital) or acquired condition in which there is an abnormal accumulation of body fluids within the skull. The congenital form may be associated with other abnormalities.
..... Click the link for more information.
). Since edema is a symptom, the underlying cause must be treated.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Edema

 

the excessive accumulation of fluid in the organs and intercellular tissue spaces of the body.

Edemas are classified according to the various conditions that can impair the drainage and retention of fluids. High pressure in the capillaries is the major factor in hydremic edemas. Hypoproteinemic edemas are primarily caused by a decrease in the amount of proteins, especially albumins, in the blood and by a drop in the colloidal osmotic, or oncotic, pressure of plasma, which is accompanied by a release of fluid from the capillary bed into the tissues. Membrane-related edemas result from increased capillary permeability owing to the effect of toxic and inflammatory processes and of disturbances of neural regulation in the capillary blood vessels.

Edema can be local—limited to a certain part of the body or organ—or general. Pronounced general edema is determined by inspection and palpation, after which a concavity remains in the edematous area. The condition is usually preceded by a substantial accumulation of fluid (about 4–9 liters) in the body. In persons suffering from heart disease (the commonest cause of hydremic edemas), edema is the most important symptom of cardiac insufficiency. It first arises in the feet and legs when the patient is standing and in the sacrum and lumbar region when the patient is lying down. These conditions then develop into total edema, or anasarca, of the subcutaneous tissue. Several conditions can arise if the fluid accumulates in the natural cavities of the body: hydrothorax is an accumulation in the pleural cavity; ascites, in the abdominal cavity; and hydropericardium, in the pericardial cavity.

Edema—chiefly hypoproteinemic—in the late stages of cirrhosis of the liver is usually combined with ascites and found mainly in the legs, lumbar region, and anterior abdominal wall. In kidney diseases, including nephritis, edema appears all over the body and face, where it is especially pronounced around the eyes. The edematous areas are soft to the touch and covered by pale skin. Salt and water retention in the kidneys, decreased concentration of proteins in the blood, and increased permeability of the vascular walls are major factors in the mechanism of the formation of these types of edema.

Aldosterone promotes fluid retention by causing the retention of sodium ions in the tissues. Thus, endocrine changes that result in the increased production of aldosterone play an important role in the origin of edema in diseases of the heart, kidneys, and liver. The production of the antidiuretic hormone vasopressin also increases in these diseases, resulting in increased reabsorption of water and salts in the renal tubules. Hormonal disturbances are the decisive factor in the development of edema in some endocrine disorders, for example, in Itsenko-Cushing syndrome. The edema observed after prolonged starvation is mainly hypoproteinemic.

Local edema in thrombophlebitis is caused by interference with the outflow of venous blood below the site of the thrombus. In such cases, the edema is firm, purple, painful to the touch, and covered with inflamed skin. When the outflow of lymph through the lymphatic system is disrupted, the surface edema on the limbs is firm, and the skin pale. Inflammatory edemas in such conditions as burns, furuncles, and erysipelas are due to increased capillary permeability and increased flow of blood into the inflamed area. The skin is reddish and painful to the touch.

Treatment of edemas is directed at the causative disease. Diuretics and special diets are prescribed.

REFERENCE

Eliseev, O. M. Oteki v klinike vnutrennikh boleznei. Moscow, 1970. (Bibliography.)

B. L. ELKONIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

edema

[ə′dē·mə]
(medicine)
An excessive accumulation of fluid in the cells, tissue spaces, or body cavities due to a disturbance in the fluid exchange mechanism. Also known as dropsy.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

oedema

, edema
Pathol an excessive accumulation of serous fluid in the intercellular spaces of tissue
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
It has been proposed that brain edema in meningiomas is associated with many factors including the size, location, and histological features of the tumor; the secretory activity of meningioma cells, meningioma with positive sex hormone receptors, venous channel compression, and occlusion by the tumor.
[16.] Lin TN, He YY Wu G, Khan M, Hsu CY Effect of brain edema on infarct volume in a focal cerebral ischemia model in rats.
As shown in [Figure 2]d, after bTBI was induced by moderate explosion, the degree of brain edema increased significantly at 1 day (76.9% [+ or -] 1.3% vs.
In this study, we found that PD-MSC administration decreased the mortality of ICH in the acute stage by suppressing hematoma expansion and by various neuroprotective effects, including the amelioration of hydrocephalus, perihematomal neuronal death, and brain edema. The present study also showed that administration of PD-MSCs increased the expression of tight junction proteins associated with the enhancement of cerebrovascular integrity.
In addition, there was significantly greater brain edema in both hemispheres of the SAH mice than in the hemispheres of the sham-operated mice at 24 h and 72 h after SAH.
Increased brain lactate is central to the development of brain edema in rats with chronic liver disease.
Cerebral edema can lead to the cerebral cortex being displaced into the cerebrospinal fluid space and veins become congested due to the brain edema compressing the dural sinuses.
Hyponatremia can result in brain edema and secondary nausea, headache, altered consciousness, and sometimes death.
Verkman, "Aquaporin-4 facilitates reabsorption of excess fluid in vasogenic brain edema," The FASEB Journal, vol.
However, our patient had asymptomatic brain edema in initiation of hemodialysis.
SAH-associated brain injury is a complex process involving inflammation, brain edema, microglial cell activation, oxidative damage, and blood-brain barrier disruption [4].