ABSTRACT
Sudden fever, headache, focal neurological findings together with various levels of unconsciousness or seizure disorders are the characteristic features for encephalitis. Herpes simplex virus type 1 is most common viral agent in etiology. Clinically, it’s difficult to diagnose the disease. Routine laboratory results are usually nonspecific. When symptoms and clinical findings confirm the diagnosis and the HSV antigen or antibody is seen in laboratory results with associated typical radiological lesions, it is life saving to start antiviral therapy immediately. In our case, provided with literature research we disscussed a 37 years old man who presented to our internal medicine department with headache, nausea, vomiting and fever, without neurological symptoms and findings, diagnosed as herpes simplex encephalitis and started asyclovir treatment.