Case report: severe course of encephalitis of unknown origin.

The exact cause of encephalitis is still unclear in many cases, although the common etiological factors of this process are viruses such as herpes simplex virus and rabies virus, and also bacteria, fungi, parasites, several medicines and autoimmune diseases. Herein, we report a case of a 56-year-old man with a history of amnestic syndrome, impaired consciousness, somnolence throughout the day, headache, dizziness and hypertension, who was admitted to hospital with suspected neurological disease, and imaging features that were consistent with encephalitis of unknown etiology. Methods which were used to examine patient: cerebrospinal fluid testing, PCR examinations for viruses, testing of antibodies against surface antigens, magnetic resonance imaging of the head, psychiatric consultation, oncology consultation. The objective of this study is to demonstrate a case about an uncommon neurologic condition, which every clinician might meet in clinical practice. In this type of cases, the use of steroids such as dexamethasone and methylprednisolone might lead to a full recovery.