Overview Encephalitis, inflammation of the brain parenchyma, can be caused by either an infection or autoimmune process. Clinical features of encephalitis include fever, altered mental status, neurological deficit and seizures. Definitive diagnosis rests on a lumbar puncture with CSF examination. Encephalitis can be difficult to distinguish from meningitis. Young, old and especially those who are immunocompromised are susceptible to developing encephalitis.
Remember In menigitis cerebral function remains normal where as, in encephalitis causes altered mental status/confusion.
Think Meningeal involvement (photophobia and nuchal rigidity) are usually absent with a pure encephalitis. Meningoencephalitis both involve the brain parenchyma and meninges
Remember HSV-1 encephalitis is the most common cause of viral encephalitis
West Nile virus infection triad encephalitis, flaccid paralysis with a polio-like presentation. A differential for Gullian Barre Syndrome
INSERT TABLE DIFFERENTIATING CSF RESULT BETWEEN INFECTIONS
Remember Temporal lobe involvement is strongly suggestive of herpes simplex virus (HSV) encephalitis
Empirical therapy with acyclovir