An inflammation of brain parenchyma due to infection with a virus. Viral encephalitis can occur as a rare complication of common infections (eg, herpes virus infections) or can occur as a characteristic presentation of rare viruses (eg, rabies virus infection). Encephalitis may be the only neurologic manifestation of infection, or may occur in association with meningitis, myelitis, radiculitis, or neuritis. Viral encephalitis is associated with neurological dysfunction. [PMID:21960712, PMID:30366550]