Encephalitis

Description:

Encephalitis is an inflammation of a brain, as a rule, caused by a viral infection or allergic reaction to a virus or a foreign protein. The brain tissue inflammation caused by a bacterial infection is also called encephalitis. When process covers a head and spinal cord, the disease is called encephalomyelitis. The inflammation is reaction of immune system of an organism to implementation of an infection. During an inflammation of tissue of brain swell. The combination of an infection and an immune response can cause a headache and fever, and in some cases and more serious symptoms.
Encephalitis meets at any age though some types of encephalitis meets at children more often.

Encephalitis reasons:

There are more than ten viruses which can cause encephalitis. They extend or through direct contact or a sting of animals. Most often encephalitis develops at the following diseases:
- chicken pox
- measles
- mumps
- Epstein-Barre's (EBV) virus
- Cytomegaloviral infection
- HIV
- herpes simplex
- the surrounding herpes (shingles)
- poliomyelitis
- rage
- arboviral infection.
Primary encephalitis is caused by direct infection with a virus while secondary encephalitis is connected with a postinfectious immune response on viral infections in other parts of a body. Secondary encephalitis can arise at measles, chicken pox, epidemic parotitis, a rubella and VEB. In average encephalitis symptoms usually begin from five to ten days after the beginning of the disease in time, manifestations are connected with disintegration of a myelin cover which covers nerve fibrils.
In rare instances encephalitis can be a consequence of vaccination against some viral diseases which are listed above. Kreyttsfeldta-Jacob's disease, very rare disease of a brain caused by infectious particles under the name prions can also cause encephalitis.

Mosquitoes are activator carriers at horse encephalitis (east and western types), encephalitis St. Louis, the State of California and the Japanese encephalitis. Lyme's disease extended by mites can cause encephalitis also. Rage most often extends from stings of animals - dogs, cats, mice, raccoons, squirrels, - quite often leads bats to encephalitis.
Horse encephalitis is transferred by mosquitoes which usually bite not people, and horses and birds. The Japanese encephalitis St. Louis is also transferred by mosquitoes. The risk of infection is highest in the middle end of summer when mosquitoes are most active in those rural areas where these viruses, as we know, circulate. Horse east encephalitis is widespread in east and southeast areas the United States; The Californian encephalitis – in the western regions. The Japanese encephalitis prevails in the most part of Asia. The viruses causing these diseases are classified as an arbovirus, and these diseases combine under the general name of arboviral encephalitis.
Herpesviridae encephalitis, the most common form of encephalitis, meets sporadic and is characterized by high mortality. The disease is observed at children and adults. This type of encephalitis makes about 10% of all cases of encephalitis, and the lethality makes about 20%.

Encephalitis symptoms:

Encephalitis symptoms in the range from very easy to very heavy can also include, such manifestations:
- headache
- fever
- lethargy (drowsiness, decrease in attention and fatigue)
- indisposition
- nausea and vomiting
- vision disorders
- tremor
- consciousness opacification (drowsiness, confusion of consciousness, nonsense and unconsciousness)
- wryneck
- attacks (spasms).
Symptoms can quickly progress, passing from lungs to heavy within several days or even several hours.

It is necessary to see immediately a doctor if the headache is not killed by drugs or body temperature increases to 40 °C, there is nausea and vomiting, a vision disorder, a stiff neck or spasms.

Diagnosis:

The diagnosis of encephalitis includes careful poll for definition of possible influence of a virus.
Necessary analyses for diagnosis of encephalitis:
- blood tests (for identification of antibodies to viral antigens and foreign proteins);
- the analysis of cerebrospinal fluid, or a spinal puncture (for identification of viral antigens and determination of culture of viruses or bacteria which can be present at cerebrospinal fluid);
- electroencephalogram (EEG)
- KT and MPT
- brain biopsy (surgical selection of a sample of fabric).

Treatment of Encephalitis:

The choice of a method of treatment of encephalitis depends on the reason. Bacterial encephalitis is treated by antibiotics. Viral encephalitis usually treat antiviral drugs, in particular apply an acyclovir, ганцикловир, foskarnt, рибавирин and a zidovudine. Are sensitive to an acyclovir a virus of a herpes simplex which becomes the most frequent reason of sporadic (not epidemic) encephalitis in the USA.
Symptoms of encephalitis it is possible to treat a number of various drugs. Corticosteroids, including Prednisolonum and dexamethasone, sometimes appoint for reduction of an inflammation and wet brain. Anticonvulsant drugs, including Phenytoinum, are used for control of a spasm. Fever can be reduced by use of acetaminophen and other febrifugal drugs.
During treatment it is necessary to control blood indicators, in particular water-salt balance.
Symptoms of encephalitis can last several weeks. In most cases encephalitis proceeds benign, without leaving behind any residual neurologic phenomena. More serious forecast, including herpesviridae encephalitis at which mortality makes from 15 to 20% on condition of treatment, and from 70 to 80% without therapy have some forms of encephalitis. Antiviral treatment is inefficient for east horse encephalitis, and mortality makes about 30%.