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Encephalitis

Inflammation of the brain.

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

About Encephalitis

Infections, and less commonly other causes, in the brain and spinal cord can cause dangerous inflammation. This inflammation can produce a wide range of symptoms, including fever, headache, seizures, change in behavior or confusion and, in extreme cases, can cause brain damage, stroke, or even death.

Infection of the meninges, the membranes that surround the brain and spinal cord, is called meningitis and inflammation of the brain itself is called encephalitis. Myelitis refers to inflammation of the spinal cord. When both the brain and the spinal cord are involved, the condition is called encephalomyelitis....Read more about Encephalitis NIH - National Institute of Neurological Disorders and Stroke

What works? Research summarized

Evidence reviews

Meta-analysis on serological effect of the primary vaccination for Japanese encephalitis of the literatures

OBJECTIVES: To summary and compare the different seroconversion rates after the primary vaccination for the Japanese encephalitis (JE), and to evaluate the serological effect of 3 kinds of JE vaccines.

Safety of alternative antiviral agents for neonatal herpes simplex virus encephalitis and disseminated infection

OBJECTIVE: To review the evidence describing the safety of ganciclovir and foscarnet in neonates in order to guide treatment for central nervous system or disseminated herpes simplex infections in cases of acyclovir shortage or resistance.

Immunogenicity against Far Eastern and Siberian subtypes of tick-borne encephalitis (TBE) virus elicited by the currently available vaccines based on the European subtype: systematic review and meta-analysis

Tick-borne encephalitis (TBE) virus, which is usually divided into European, Far Eastern and Siberian subtypes, is a serious public health problem in several European and Asian countries. Vaccination is the most effective measure to prevent TBE; cross-subtype protection elicited by the TBE vaccines is biologically plausible since all TBE virus subtypes are closely related. This manuscript systematically explores available data on the cross-subtype immunogenicity elicited by the currently available Western vaccines based on the European subtype. Completed immunization course of 3 doses of both Western vaccines determined very high seroconversion/seropositivity rates against both Far Eastern and Siberian subtypes among previously flavivirus-naïve subjects. All but one study found no statistically significant difference in titers of neutralizing antibodies against strains belonging to homologous and heterologous subtypes. Pooled analysis of randomized controlled trials on head-to-head comparison of immunogenicity of Western and Russian TBE vaccines did not reveal differences in seroconversion rates against Far Eastern isolates in either hemagglutination inhibition (risk ratio = 0.98, p = 0.83) or enzyme-linked immunosorbent (risk ratio = 0.95, p = 0.44) assays after 2 vaccine doses. This suggests that, in regions where a heterogeneous TBE virus population circulates, vaccines based on the European subtype may be used alongside vaccines based on the Far Eastern subtype. Studies on the field effectiveness of TBE vaccines and investigation of vaccination failures, especially in countries where different subtypes co-circulate, will further elucidate TBE vaccination-induced cross-subtype protection.

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Summaries for consumers

Ticks: Tick-borne encephalitis (TBE)

The risk of getting TBE is much lower than the risk of getting Lyme disease. Only a small proportion of ticks are infected with the virus. And even if a tick is infected, the virus will not necessarily spread to the people the tick feeds on.If the infection does spread, some people will develop symptoms. In children the infection often goes unnoticed, or the symptoms are only mild and temporary. The symptoms of a mild TBE infection are similar to flu symptoms: fever, headaches, vomiting and dizziness.TBE is diagnosed by testing blood or cerebrospinal fluid for the TBE virus.So far, there is no treatment that specifically fights the TBE virus. Instead, treatment only focuses on relieving the symptoms. Because TBE is caused by a virus, antibiotics do not help. No antiviral drugs are currently available.Although TBE usually clears up without any lasting health problems, the symptoms can last for months. In very rare cases it can be fatal. Serious complications are quite a lot more common in adults than in children. Children normally only have a mild form of TBE: serious symptoms are rare and there are hardly ever any lasting effects.

Vaccines for preventing tick‐borne encephalitis

Tick‐borne encephalitis (TBE) is a disease of the central nervous system caused by a tick‐borne viral infection. TBE can lead to severe neurological syndromes, which can result in death. Many species of wild and domestic animals act as hosts of ticks; transmission to humans occurs often in woodland areas, especially during the summer, which is the time of greatest human outdoor activity. TBE is particularly prevalent in Central and Eastern Europe.

Treatment for Fisher syndrome, Bickerstaff's brain stem encephalitis and related disorders

Fisher syndrome is an uncommon paralysing illness, usually caused by autoimmune inflammation of nerves following an infection. Fisher syndrome is characterised by impairment of eye movements, abnormal co‐ordination and loss of tendon reflexes. It is a variant of Guillain‐Barré syndrome. Unlike Guillain‐Barré syndrome, it does not cause limb or respiratory muscle weakness. In Western countries Fisher syndrome represents between 5% and 10% of Guillain‐Barré syndrome cases, but it is more common in Eastern Asia, for example 25% of cases in Japan. Bickerstaff's brain stem encephalitis shares many clinical features but also includes altered consciousness and signs of central nervous system inflammation. Treatment strategies tried have been immunotherapies such as plasma exchange or intravenous immunoglobulin which are used in Guillain‐Barré syndrome. This systematic review found no randomised controlled trials of treatments for Fisher syndrome, Bickerstaff's brain stem encephalitis or their variants. Observational studies suggest that Fisher syndrome always and Bickerstaff's brain stem encephalitis usually recovers completely. Randomised controlled trials are needed to establish the value of immunotherapies or other treatments.

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Terms to know

Brain
The part of the central nervous system that is contained within the skull (cranium).
Inflammation
Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.
Meninges
The three thin layers of tissue that cover and protect the brain and spinal cord.
Meningitis
Inflammation of the meninges (three thin layers of tissue that cover and protect the brain and spinal cord). Meningitis is usually caused by a bacterial or viral infection, but sometimes is caused by cancer, drug allergies, or inflammatory diseases.
Spinal Cord
A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.

More about Encephalitis

Photo of an adult woman

Other terms to know: See all 5
Brain, Inflammation, Meninges

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