Аннотация:Encephalitis is a severe pathology of the nervous sys- tem that is difficult to diagnose and treat. Currently, there are a num- ber of limitations for verifying the etiology of encephalitis. The most common symptom is a change in behavior, a decrease in the level of consciousness up to coma, epileptic seizures, and focal neurological pathology. Often, with viral encephalitis, there is a hemorrhagic trans- formation of the inflammation focus, interstitial edema in the area of the focus, often with a displacement of the mid-stem structures, which may require decompression craniotomy.