Modern application of mathematical methods for analyzing EEG recordings is limited due to the phenomenon of information averaging. In these conditions, it is important to find the most likely method for improving the quality of diagnosis of paroxysmal pathological patterns that have a short “life”, such as outbreaks and subclinical paroxysms. The purpose of the study was to evaluate the possibility of excluding interictal activity from a long-term EEG study in order to achieve its information “enrichment” by forming conditional sequences of pathological changes representing its main clinical task. Forty people of different ages and both sexes were examined. The control group included 20 patients aged 12–67 years with direct detection of spike-wave activity on the EEG. The comparison group consisted of 20 patients aged 10–66 years with no spike-wave activity in the recording. It has been shown that interictal data obtained in patients with epileptiform phenomena are not of significant interest for the main group of clinical studies. The exclusion of these data leads to the “enrichment” of information due to the sequential placement of paroxysmal patterns and makes it possible to obtain not only more compact results of examinations of the pathological component, but also to form a basis for developments using technologies for their subsequent mathematical analysis.