Encephalitis, or brain inflammation, is an acute inflammation of the brain. With meningitis, it is called meningoencephalitis. It starts with symptoms such as severe headache, neck stiffness and fever. This disease is caused by viruses such as mumps, herpes simplex, influenza, infectious hepatitis, and infectious mononucleosis. Encephalitis caused by the rabies virus is fatal. This disease is also called aseptic meningitis to distinguish it from purulent meningitis, considering the absence of bacteria. In the cerebrospinal fluid taken for diagnosis, glucose, normal cells, lymphocytes and albumin are found to be increased. Because lymphocytes increase too much, there is another type of viral meningitis called lymphocytic choriomeningitis, which, like the flu, is seen as epidemic. In such cases, symptoms of meningitis such as headache, fever and neck stiffness are mild. The disease usually heals in 1-2 weeks with symptomatic treatment. Antiviral and pain reliever and antipyretic drugs are used in the treatment. Patients who are unconscious, such as in coma, are taken into care in the hospital, and the convulsions seen in the form of muscle contractions are tried not to harm the patient.