Encephalitis

Encephalitis is an inflammation of the brain parenchyma, resulting from the direct entry of viruses. Acute disseminated encephalomyelitis is a brain and spinal cord inflammation that is caused by an inflammatory response to a virus or other foreign protein. Both diseases are usually caused by viruses. Symptoms may include fever, headache, an altered mental status, seizures or focal neurological deficits. The diagnosis requires CSF analysis and neuro-radiological imaging. There is supportive treatment, in some cases, antiviral medications are given. (Editor’s note: Cave The herpes simplex virus encephalitis goes untreated in 70 of 100 cases fatal case of any suspicion of encephalitis, the emergency proper diagnosis with CSF analysis and neuro-radiological imaging should be performed [MRI + KM] Even with suspected encephalitis.. is necessary initiation of antiviral therapy [aciclovir] and possibly antibiotic treatment. Only when the results of CSF analysis have ruled out infection with herpes viruses, this treatment can be stopped. Supportive done of course symptomatic treatment.)

Encephalitis is an inflammation of the brain parenchyma, resulting from the direct entry of viruses. Acute disseminated encephalomyelitis is a brain and spinal cord inflammation that is caused by an inflammatory response to a virus or other foreign protein. Both diseases are usually caused by viruses. Symptoms may include fever, headache, an altered mental status, seizures or focal neurological deficits. The diagnosis requires CSF analysis and neuro-radiological imaging. There is supportive treatment, in some cases, antiviral medications are given. (Editor’s note: Cave The herpes simplex virus encephalitis goes untreated in 70 of 100 cases fatal case of any suspicion of encephalitis, the emergency proper diagnosis with CSF analysis and neuro-radiological imaging should be performed [MRI + KM] Even with suspected encephalitis.. is necessary initiation of antiviral therapy [aciclovir] and possibly antibiotic treatment. Only when the results of CSF analysis have ruled out infection with herpes viruses, this treatment can be stopped. Supportive done of course symptomatic treatment.) etiology the encephalitis is usually a primary manifestation or a secondary (post-infectious) immunologic complication of viral infection. Primary viral infection viruses that cause a primary encephalitis, penetrate directly into the brain. These infections can be: epidemic (. Eg by arbovirus, echo virus, coxsackie virus or poliovirus [in some underdeveloped countries]) Sporadic (eg by herpes simplex, rabies, varicella zoster or mumps. virus) the data transmitted by mosquitoes arbovirus encephalitis infect humans in the spring, summer and early autumn, when the weather is warm. The incidence in the United States varies from 150 to> 4000 cases per year, mostly in children. (Editor’s note: In Europe arboviruses not play such a big role as in North America caused in Germany, for example, the TBE virus disease 260 cases in total in 2010…) Most cases occur during epidemic outbreaks. Arbovirus encephalitis in the US virus spread mortality comments La Crosse virus (California virus) primary in the north-central United States, but geographically widespread probability <1% is probably not enough attention is for the most cases of arbovirus encephalitis in children responsible Saint Louis encephalitis virus usually in the central and eastern United States - By 1975 the occurrence every 10 years; now rare West Nile Virus everywhere in the US Approximately 9% of patients with CNS involvement since 2009 spread from the east coast, where they first emerged in 1999 in appearance, and in all western states. Eastern equine encephalitis virus-eastern US Approximately 50-70% occurs in small epidemics every 10-20 years, mostly in young children and persons> 55 years Western-equine encephalitis virus – – For unknown reasons largely disappeared from the US since 1988 , In the US, the herpes simplex virus (HSV) causes the most common sporadic encephalitis; occur hundreds to several thousand cases per year. Most are caused by HSV-1, HSV-2, however, may be more common in immunocompromised patients. The HSV encephalitis occurs throughout the year before, mainly infected patients <20 or> 40 years old and goes untreated often fatal. A primary encephalitis can occur as a late result of a viral infection. The most common types are HIV encephalopathy and dementia (HIV-associated dementia) Subacute sclerosing panencephalitis (occurring years after a measles infection and is accepted by the that this is the reactivation of the original infection; it is in Western countries today rare-Subacute sclerosing panencephalitis (SSPE)) progressive multifocal leukoencephalopathy (wird- caused by the reactivation of the JC virus, progressive multifocal leukoencephalopathy (PML)) immune response encephalitis can occur as a secondary immunologic complication of a particular virus infection or vaccination. An inflammatory demyelination in the brain and spinal cord can occur 1-3 weeks later (as acute disseminated encephalomyelitis). The immune system attacks one or more CNS antigens are similar to the proteins of the infectious agent. The most common causes were usually measles, rubella, chickenpox and mumps (all are now rare because of widespread childhood vaccination) (, Variolava- and live virus vaccines such. As the older Rabies vaccine, which is made from sheep or goat brain ). In the US, most cases are caused by influenza A or B virus, enterovirus, Epstein-Barr virus, hepatitis A or B virus or HIV today. Encephalopathies, of autoantibodies against neuronal membrane proteins caused (eg. B. N, N’-methyl-d-aspartate receptors) can mimic viral encephalitis. Pathophysiology of acute encephalitis occur inflammation and brain edema in infected areas in the Großhirnemisphären, in the brain stem, cerebellum and occasionally in the spinal cord. Petechial bleeding can occur in severe infections. The direct virus infection of the brain usually damaged neurons and sometimes produces microscopically visible inclusion bodies. A serious infection, particularly an untreated HSV encephalitis can cause hemorrhagic Hirnnekrose. Acute disseminated encephalomyelitis is characterized by multifocal areas of demyelination perivenous and lack of virus detection in the brain. Symptoms and signs Symptoms include fever, headache and altered mental status, often accompanied by seizures and focal neurological deficits. Gastrointestinal or respiratory prodrome may precede the actual symptoms. Meningeal irritation signs are lightweight and less pronounced than other manifestations usually. A status epilepticus, v. a. a convulsive status epilepticus, or a coma suggest a severe inflammation in the brain and a poor prognosis include. representing olfactory seizures that as Aura bad odors (rotten eggs, burnt meat), indicate the involvement of the temporal lobe and speak for HSV encephalitis. Diagnosis MRI CSF examination is likely encephalitis in patients with unexplained mental status changes. The clinical picture and differential diagnoses can be certain diagnostic studies appear useful, almost always, however, is performed an MRI and CSF analysis (incl. PCR for HSV and other viruses), typically together with other studies (eg. As serological tests) to to identify the causative virus. (Editor’s note: MRI and CSF analysis are absolutely necessary.) Despite extensive laboratory tests the cause of many encephalitis remains unknown. MRI Contrast-enhanced MRI is sensitive for early HSV encephalitis is shown an edema in the orbitofrontal and temporal areas that typically infects the HSV. The MRI shows a demyelination in multifocal leukoencephalopathy progressive and can basal ganglia and thalamic abnormalities in West Nile encephalitis and eastern equine encephalitis represent. MRI can also exclude lesions that mimic a viral encephalitis (z. B. Brain abscess, sagittal sinus thrombosis). CT is much less sensitive to HSV encephalitis than MRI, but can be helpful because it is readily available and can exclude disorders in which a lumbar puncture would be risky (eg. As space-occupying lesions, hydrocephalus, cerebral edema) .Liquortests In presence of encephalitis is the cerebrospinal fluid (Liquoranomalien in various diseases) by a lymphocytic pleocytosis, normal glucose levels slightly increased total protein and the absence of pathogens in culture by Gram staining (similar to the CSF in aseptic meningitis) characterized. A pleocytosis may be polymorphkernig in severe infections. The CSF abnormalities can often only after 8-24 h after the onset of symptoms develop. In hemorrhagic necrosis erythrocytes can pass into the cerebrospinal fluid and increase the protein content. (Editor’s note: The protein indeed increases, is caused this but mainly by a circulation disorder.) The glucose levels in the cerebrospinal fluid may be low when the varicella-zoster virus, or lymphocytic choriomeningitis virus causing. (Editor’s Note: Glucose is hardly studied in Germany itself, it is recommended lactate to examine glucose may be slightly reduced even in normal people, but is irrelevant for the assessment..) Evidence in the CSF by PCR provides for HSV 1, HSV-2, varicella-zoster virus, cytomegalovirus, enteroviruses, and JC virus which diagnostic examination is of choice. the PCR is particularly sensitive and specific for HSV in cerebrospinal fluid. However, the results may not be readily available, and despite the advances in technology, false-negative and false-positive results can choose from a variety of reasons still occur; it does not always have technical errors (eg. as may the blood in a slightly traumatic cerebrospinal fluid sample in the PCR amplification step to inhibit). False-negative results can occur in early HSV-1 encephalitis. In such cases, the tests should be repeated within 48 to 72 hours. In the viral cultures from CSF grow enteroviruses, but not most other viruses. Therefore, viral cultures of the cerebrospinal fluid in the diagnosis are rarely used. Viral IgM titers in the CSF are often useful in the diagnosis of acute infection, v. a. West Nile encephalitis, for which they are more reliable than the PCR. (Editor’s note: German (European) standards: There are no titer investigated Rather antigen-specific antibody indices (AI) for the respective viruses for this account for the blood-CSF barrier function…) IgG and IgM titers in the CSF may be more sensitive to the varicella-zoster virus encephalitis as the PCR. Combined serological tests of cerebrospinal fluid and blood must be taken from a distance of several weeks in the acute phase and convalescence time: you can have a rise in specific for certain viral infections virus titer nachweisen.Hirnbiopsie A brain biopsy may be indicated in patients who deteriorate clinically, the poorly responsive to treatment with acyclovir or other antimicrobial drugs or have a lesion that can not be diagnosed otherwise. However, the brain biopsy provides only an unsatisfactory result, unless it is directed to an anomaly that was seen in the MRI or CT. The forecast recovery from viral encephalitis can take a long time. The mortality rate varies depending on the cause, but also the seriousness with epidemic outbreaks vaiiert by the same virus in different years. Permanent neurological deficits are common in patients who survive severe infection, often. Treatment Symptomatic treatment acyclovir for HSV or varicella-zoster virus encephalitis Symptomatic therapy includes the treatment of fever, dehydration, electrolyte derailments and seizures. Fluid balance should be balanced. are excluded to HSV encephalitis and varicella-zoster virus encephalitis, immediate treatment with acyclovir taken 10 mg / kg i.v. every 8 hours, which is usually continued for 14 days or excluded by these viruses. Acyclovir is relatively nontoxic, but can cause abnormal liver function, bone marrow suppression and transient renal failure. The slow iv administration of acyclovir for 1 h with adequate hydration helps prevent nephrotoxicity. However, because exclusion of bacterial CNS infection in apparently seriously ill patients is often difficult, frequently done an empirical antibiotic therapy until bacterial meningitis were excluded. If encephalitis is caused due to an immunological reaction, treatment corticosteroids (prednisone or methylprednisolone), and plasma exchange, or IV may comprise immunoglobulin. Conclusion viruses that cause epidemic outbreaks or sporadic infections can penetrate into the brain parenchyma and infect (and therefore cause encephalitis) and / or a post-infectious inflammatory demyelination trigger (acute disseminated encephalomyelitis). The encephalitis veruracht fever, headaches and an altered mental status, often accompanied by seizures and focal neurological deficits. Perform a contrast-enhanced MRI and CSF testing. are excluded to HSV encephalitis and varicella-zoster virus encephalitis, immediately treated with acyclovir and continue the treatment for 14 days or is excluded to infection with these viruses.

Health Life Media Team

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