Herpes simplex viruses
(HSV-1 and HSV-2) produce a variety of infections involving
mucocutaneous surfaces, the CNS, and occasionally visceral organs.
HSV encephalitis is the most common identified cause of acute,
sporadic viral encephalitis in the US, comprising of 10-20% of all
cases. Distribution of disease is throughout the year and cases
have a biphasic age peak at 5-30 years and over 50 years of
age.
Clinically, HSV encephalitis
arises as acute onset of fever and focal neurologic, especially
temporal lobe, signs. Differentiation of HSV encephalitis from
other viral encephalitides and other focal infectious and
non-infectious processes is difficult, as there is no reliable
noninvasive radiologic or virologic technique available.
