Cardinal symptoms of encephalitis include fever, headache, neck stiffness, photophobia, confusion and seizures. Clinical examination will reveal altered mental status ranging from somnolence to lethargy and coma. Delirium, cranial nerve palsies, ataxia, rash and sign of increased intracranial pressure may be seen. It is not always possible to ascertain the specific cause of encephalitis from clinical presentation alone. However there are features that can give some clue to possible etiology. Arbovirus encephalitis often heralds with a flu-like syndrome followed by increasing confusion and stupor. Herpes simplex encephalitis often presents with an abrupt change in behavior, memory loss, focal or generalized seizures, and speech concerns. West Nile encephalitis may present with flaccid, asymmetric motor weakness with altered sensorium of variable degree. Varicella may manifest with cerebellar features as Japanese encephalitis presenting with basal ganglia symptoms.