Cerebral edema

Jump to: navigation, search

WikiDoc Resources for Cerebral edema

Articles

Most recent articles on Cerebral edema

Most cited articles on Cerebral edema

Review articles on Cerebral edema

Articles on Cerebral edema in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Cerebral edema

Images of Cerebral edema

Photos of Cerebral edema

Podcasts & MP3s on Cerebral edema

Videos on Cerebral edema

Evidence Based Medicine

Cochrane Collaboration on Cerebral edema

Bandolier on Cerebral edema

TRIP on Cerebral edema

Clinical Trials

Ongoing Trials on Cerebral edema at Clinical Trials.gov

Trial results on Cerebral edema

Clinical Trials on Cerebral edema at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Cerebral edema

NICE Guidance on Cerebral edema

NHS PRODIGY Guidance

FDA on Cerebral edema

CDC on Cerebral edema

Books

Books on Cerebral edema

News

Cerebral edema in the news

Be alerted to news on Cerebral edema

News trends on Cerebral edema

Commentary

Blogs on Cerebral edema

Definitions

Definitions of Cerebral edema

Patient Resources / Community

Patient resources on Cerebral edema

Discussion groups on Cerebral edema

Patient Handouts on Cerebral edema

Directions to Hospitals Treating Cerebral edema

Risk calculators and risk factors for Cerebral edema

Healthcare Provider Resources

Symptoms of Cerebral edema

Causes & Risk Factors for Cerebral edema

Diagnostic studies for Cerebral edema

Treatment of Cerebral edema

Continuing Medical Education (CME)

CME Programs on Cerebral edema

International

Cerebral edema en Espanol

Cerebral edema en Francais

Business

Cerebral edema in the Marketplace

Patents on Cerebral edema

Experimental / Informatics

List of terms related to Cerebral edema

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Synonyms and Keywords: Cerebral oedema.

Overview

Cerebral edema is an excess accumulation of water in the intra- and/or extracellular spaces of the brain.

Pathophysiology

Vasogenic Cerebral edema

Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier (BBB). This allows normally excluded intravascular proteins and fluid to penetrate into cerebral parenchymal extracellular space. Once plasma constituents cross BBB the edema spreads, this may be quite fast and widespread. As water enters white matter it moves extracellularly along fiber tracts and can also affect the gray matter. This type of edema is seen in response to trauma, tumors, focal inflammation, late stages of cerebral ischemia and hypertensive encephalopathy.

Some of the mechanisms contributing to BBB dysfunction are: physical disruption by arterial hypertension or trauma, tumor-facilitated release of vasoactive and endothelial destructive compounds (e.g. arachidonic acid, excitatory neurotransmitters, eicosanoids, bradykinin, histamine and free radicals).

Cytotoxic Cerebral edema

In this type of edema the BBB remains intact. This edema is due to the derangement in cellular metabolism resulting in inadequate functioning of the sodium and potassium pump in the glial cell membrane. As a result there is cellular retention of sodium and water. There are swollen astrocytes in gray and white matter. Cytoxotic edema is seen with various intoxications (dinitrophenol, triethyltin, hexachlorophene, isoniazid), in Reye's syndrome, severe hypothermia, early ischemia, encephalopathy, early stroke or hypoxia, cardiac arrest, pseudotumor cerebri, and cerebral toxins.

Osmotic Cerebral edema

Normally cerebral-spinal fluid (CSF) and exocoelomic fluid (ECF) osmolality of the brain is slightly greater than that of plasma. When plasma is diluted by excessive water intake (or hyponatremia), syndrome of inappropriate antidiuretic hormone secretion (SIADH), hemodialysis, or rapid reduction of blood glucose in hyperosmolar hyperglycemic state (HHS), formerly hyperosmolar non-ketotic acidosis (HONK), the brain osmolality will then exceed the serum osmolality creating an abnormal pressure gradient down which water will flow into the brain causing edema. It effects the brain so severely that the victim feels like drowning until he/she dies the slow painful death.

Hydrostatic Cerebral edema

This form of cerebral edema is seen in acute, malignant hypertension. It is thought to result from direct transmission of pressure to cerebral capillary with transudation of fluid into the ECF.

Interstitial Cerebral edema

Interstitial cerebral edema occurs in obstructive hydrocephalus. This form of edema is due to rupture of CSF-brain barrier: permits CSF to penetrate brain and spread in the extracellular space of white matter. Differentiated from vasogenic edema in that fluid contains almost no protein.

High Altitude Cerebral edema

High altitude cerebral edema (or HACE) is a severe (usually fatal) form of altitude sickness. HACE is the result of swelling of brain tissue from fluid leakage. Symptoms can include headache, loss of coordination (ataxia), weakness, and decreasing levels of consciousness including disorientation, loss of memory, hallucinations, psychotic behavior, and coma. It generally occurs after a week or more at high altitude. Severe instances can lead to death if not treated quickly. Immediate descent is a necessary life-saving measure (2,000 - 4,000 feet). There are some medications (e.g. dexamethasone) that may be prescribed for treatment in the field, but these require proper medical training in their use. Anyone suffering from HACE must be evacuated to a medical facility for proper follow-up treatment. A gamow bag can sometimes be used to stabilize the sufferer before transport or descending.

Climbers may also suffer high altitude pulmonary edema (HAPE), which affects the lungs. While not as life threatening as HACE in the initial stages, failure to descend to lower altitudes or receive medical treatment can also lead to death.

Causes

References




Linked-in.jpg