[Rhythmic and periodic EEG patterns. Classification and clinical significance.].

The review presents the methodology of electroencephalography (EEG) background analysis, sporadic epileptiform discharges classification, and description of the rhythmic and periodic patterns in patients with primary and secondary brain damage. It describes the process of decision making in starting non-convulsive status epilepticus treatment of patients with EEG-verified non-convulsive status epilepticus and the signs of 'malignant' patterns indicating the irreversibility of brain injury.