Аннотация:Clinical differentiation between nonconvulsive status epilepticus (NCSE) and encephalopathy remains challenging. Some patients with encephalopathy exhibit periodicdischarges on electroencephalography. In certain cases, however, it is rather difficultto differentiate between epileptic and periodic discharges. The lack of clear differentiation criteria makes it difficult to effectively analyze the studies in this field. In patientswith refractory status epilepticus, the wrong diagnosis can lead to insufficient therapy,thereby increasing the frequency of convulsions and the likelihood of a poor outcome.Alternatively, aggressive therapy with antiepileptic drugs and anesthetic agents canaggravate neuronal damage and worsen encephalopathy. In this review, we aimed todetermine whether clinical and instrumental methods can be used to differentiatebetween encephalopathy and epileptic states, to improve the selection of the appropriate treatment strategies. The review considers different approaches to diagnosingencephalopathy and seizures in critically ill patients. In spite of electroencephalography (EEG) still being the main method used to objectively identify brain dysfunctionand diagnose epileptic discharges over the past 60 years, improvements in EEG techniques have been accompanied by increase in our understanding of the limitations ofelectrophysiological methods, leading to the use of additional tools for the differentialdiagnosis of seizures and encephalopathy. Current studies aim to develop multimodalapproaches to the differential diagnosis of encephalopathy and NCSE. Modern reportsdescribe clinical and instrumental approaches for accurately differentiating encephalopathy and epileptic conditions in patients treated in the intensive care unit basedon clinical data, EEG, magnetic resonance imaging, positron emission tomography,biochemical analyses, and immune values.