acute disseminated encephalitis

encephalitis /en·ceph·a·li·tis/ (en-sef″ah-li´tis) pl. encephali´tides   Inflammation of the brain.

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acute disseminated encephalitis  see under encephalomyelitis.

equine encephalitis  see under encephalomyelitis.

hemorrhagic encephalitis  that in which there is inflammation of the brain with hemorrhagic foci and perivascular exudate.

herpes encephalitis  that caused by herpesvirus, characterized by hemorrhagic necrosis of parts of the temporal and frontal lobes.

HIV encephalitis  see under encephalopathy.

Japanese B encephalitis  a form of epidemic encephalitis of varying severity, caused by a flavivirus and transmitted by the bites of infected mosquitoes in eastern and southern Asia and nearby islands.

La Crosse encephalitis  that caused by the La Crosse virus, transmitted by Aedes triseriatus and occurring primarily in children.

lead encephalitis  see under encephalopathy.

postinfectious encephalitis , postvaccinal encephalitis acute disseminated encephalomyelitis.

St. Louis encephalitis  a viral disease first observed in Illinois in 1932, closely resembling western equine encephalomyelitis clinically; it is usually transmitted by mosquitoes.

tick-borne encephalitis  a form of epidemic encephalitis usually spread by the bites of ticks infected with flaviviruses, sometimes accompanied by degenerative changes in other organs.

West Nile encephalitis  a usually mild, febrile form caused by the flavivirus West Nile virus, transmitted by Culex mosquitoes and first observed in Uganda; symptoms may include drowsiness, severe frontal headache, maculopapular rash, abdominal pain, loss of appetite, nausea, and generalized lymphadenopathy.

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acute disseminated encephalitis.

See acute disseminated encephalomyelitis.

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encephalitis

inflammation of the brain. Changes in vessel walls, as well as of nervous tissue, are almost a constant feature of encephalitis.

There are many types of encephalitis, depending on the causative agent and the structures involved. A large percentage of the cases are caused by viruses, some of them, e.g. equine encephalomyelitis, being transmitted from animals to humans. Clinically encephalitis is characterized by initial signs of nervous irritation including muscle tremor, excitement and convulsions, followed by a stage of loss of function characterized by weakness, paralysis, coma and death. The more acute and serious symptoms may include fever, delirium, convulsions, coma, and, in a significant number of patients, death.

Many encephalitides are accompanied by involvement of the spinal cord and are more correctly classified as encephalomyelitides. See also encephalomyelitis.

The etiologically or geographically specific diseases are listed under their specific titles. Human pathogens which sometimes infect animals include Central European, Far Eastern Russian tick-borne encephalitides, Omsk hemorrhagic fever, Kyasanur forest disease. Viruses isolated from asymptomatic cases of encephalomyelitis include Kunjun virus.

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acute disseminated encephalitis

postinfection encephalitis.

arthropod-borne encephalitis

a group of viral encephalitides of humans in which animals play some epidemiological part. See togaviridae, flaviviridae.

canine distemper encephalitis

a demyelinating encephalitis, most severe in the cerebellum and optic tracts, is a feature of infection by canine distemper virus.

demyelinating encephalitis

seen in certain viral infections, e.g. canine distemper, caprine arthritis-encephalitis and visna of sheep.

equine herpesvirus encephalitis

see equine herpesvirus myeloencephalitis

granulomatous encephalitis

see granulomatous meningoencephalomyelitis.

histiocytic encephalitis

see granulomatous meningoencephalomyelitis.

Israeli turkey encephalitis

see Israeli turkey encephalomyelitis.

Japanese B encephalitis

believed to be primarily a disease of birds that are the source of infection for animals, including humans, pigs and horses. Transmission is by mosquito. Affected horses show a wide variety of signs including incoordination, excitability and blindness. Most cases recover. Ruminants show little clinical effect. Pigs are a major source of virus and extensive losses occur by way of encephalitis in young pigs and abortion and stillbirth in adult sows.

Murray Valley encephalitis

there is tentative evidence of clinically inapparent infection of horses in Australia with this flavivirus virus during an epidemic of the disease in humans.

Nipah virus encephalitis

occurred on the Malaysian peninsula as an epidemic in pig farmers. Pigs are the source of the virus which has antigenic relationship to Hendra virus.

old dog encephalitis

a chronic, progressive, sclerosing panencephalitis in mature dogs; characterized by motor and mental deterioration, blindness, pacing and circling. Believed to be caused by distemper virus, but there are distinct differences from distemper encephalitis.

Ontario encephalitis

see hemagglutinating encephalomyelitis virus disease of pigs.

postinfection encephalitis

an acute disease of the central nervous system seen in patients convalescing from infectious, usually viral, diseases.

postvaccinal encephalitis

acute encephalitis sometimes occurring after vaccination, mediated by immune mechanisms.

Powassan encephalitis

a tick-borne flavivirus disease of humans with serological but no clinical evidence of infection in nearby goats.

Pug encephalitis

see Pug meningoencephalitis.

Ross River encephalitis

there is tentative evidence of clinically inapparent infection of horses in Australia with the causative mosquito-borne alphavirus virus of this human disease.

Russian spring-summer encephalitis

a similar and probably identical disease to the flavivirus that causes louping ill of sheep, occurring in central Europe. It is a disease of humans occurring in epidemics related to the prevalence of vector ticks in forests where the disease is most common. Lesions are present in organs other than the brain. The severity varies from mild to fatal.

St. Louis encephalitis

an arthropod-borne flavivirus infection, first observed in 1932 in Illinois. It is a serious pathogen of humans, but does not cause disease in animals.

toxoplasma encephalitis

see toxoplasmosis.

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acute disseminated encephalitis

Neurology An acute complication of viral infection–1:1000 cases of measles or vaccination–1:106 measles vaccinations, involving the entire brain and spinal cord or focally affecting a nerve or cord root Clinical Meningial signs and, if serious, coma and death Treatment None