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Acute viral encephalitis in children: Clinical manifestations and diagnosis

Hordur S Hardarson, MD
Section Editors
Sheldon L Kaplan, MD
Gary R Fleisher, MD
Douglas R Nordli, Jr, MD
Deputy Editor
Carrie Armsby, MD, MPH


Viral infection of the central nervous system most often leads to meningitis, meningoencephalitis, or encephalitis, in descending order of frequency [1]. Encephalitis is inflammation of the brain parenchyma, manifest by neurologic dysfunction (eg, altered mental status, behavior, or personality; motor or sensory deficits; speech or movement disorders; seizure) [2].

Strictly speaking, encephalitis is a pathological diagnosis; however, in practice, most patients with encephalitis are diagnosed based on clinical manifestations of brain dysfunction and laboratory or imaging evidence of inflammation (ie, white blood cells in the cerebrospinal fluid and/or inflammation on brain imaging).

The clinical manifestations and diagnosis of viral encephalitis in children will be discussed here. The pathogenesis, etiology, treatment, and prevention of viral encephalitis in children are discussed separately. (See "Acute viral encephalitis in children: Pathogenesis, incidence, and etiology" and "Acute viral encephalitis in children: Treatment and prevention".)


Central nervous system (CNS) infections are described according to the site of infection:

Encephalitis – Encephalitis is inflammation of the brain parenchyma and is associated with neurologic dysfunction. Characteristic clinical features include altered mental status (decreased level of consciousness, lethargy, personality change, unusual behavior), seizures, and/or focal neurologic signs, often accompanied by fever, headache, nausea, and vomiting [3]. (See 'Clinical features' below.)

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Literature review current through: Nov 2017. | This topic last updated: Oct 06, 2016.
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