[Viral encephalitis].

Acute viral and other infectious causes of encephalitis usually produce fever, headache, stiff neck and alterations in consciousness, focal neurologic signs and seizures. A large number of viral and nonviral agents can cause encephalitis. Arthropod-borne viruses peak in summer, the tick-borne infections occur in early summer, enterovirus infections in later summer and mumps in the winter and spring.