Diagnostic possibilities of cognitive EEG in patients with dyscirculatory encephalopathy with mild cognitive impairment

Abstract

Object: identification of electrophysiological features in patients with dyscirculatory encephalopathy at the stage of moderate cognitive disorders according to the developed scenario of registration of EEG with cognitive load. Materials and methods: the study was conducted in the conditions of MBUZ GB No. 1 «Polyclinic for adults», Department of Medical and Biological Physics of the Rostov State Medical University during 2016-2019. A total of 80 patients with dyscirculatory encephalopathy and vascular risk factors were examined, who made up 3 observation groups: «A», «B» and «C». Group «A» is represented by patients with grade I and II DEP and concomitant moderate cognitive disorders, group «B» — patients diagnosed with grade I DEP, cognitively healthy according to the results of neuropsychoological testing (40 and 25 people, respectively), control group «C» —15 people, without manifestations of DEP and cognitive disorders. All patients underwent electroencephalogram registration using the Encephalan-131-03 device. Results: the detected neuropsychiatric disorders in patients with DEP are a reflection of violations of the bioelectric activity of the brain. A tendency to shift bioelectric activity towards slow waves has been revealed according to statistical analysis. The aggravation of the degree of cognitive disorders correlates with a decrease in the activity of the a-rhythm by 12% and an increase in the activity of the δ-rhythm by 16%. According to the spectral analysis, the reflection of cognitive impairments on the parameters of the α- and δ-rhythm was also revealed. As the power of the α-rhythm decreases and above the δ-rhythm, the pathological processes associated with cognitive impairment in the brain in patients with DEP are aggravated. Also among the pathognomonic changes detected by spectral analysis is a significant asymmetry in all leads, and it was especially pronounced in the frontal (Fp1, Fp2) and temporal (T3, T4, T5, T6) areas of the brain. Conclusions: Thus, a new method for studying the EEG in patients with DEP makes it possible to detect characteristic differences, the most significant changes were found in the α- and δ-bands. Changes in cognitive activity reflected in the EEG can serve as additional diagnostic criteria, provided that the experiment is extended.