Aim of the study was to analyze the event-related synchronization/desynchronization of brain electrical activity during visual selection task in patients underwent on-pump coronary artery bypass grafting (CABG) with and without postoperative cognitive dysfunction (POCD). Material and methods. The study included 32 men who underwent on-pump CABG, mean age 57.2 ± 6.08 years. All patients carried out extended neuropsychological testing, a multi-channel computer electroencephalography (EEG) 3-5 days before CABG and on the 7-10th day after the surgery. The POCD was determined according to the criterion: 20 % decrease in the cognitive indicator compared to that at baseline on 20 % of the tests included in the neuropsychological battery. Monopolar EEGs were recorded in 62 sites of 10-20 system with NEUVO encephalograph (Compumedics, USA) during cognitive task performing in patients wi h and without POCD. Statistical processing was performed using the STATISTICA 10.0. Results. It was found that the POCD patients had less pronounced theta desynchronization in the left frontal-central regions during the stage of 200-400 ms at the 7-10 days after CABG in comparison to patients without cognitive decline. Moreover, in the left parietal leads POCD patients had decreased theta desynchronization during the stage of 200-400 ms even before the surgery. At the 7-10 days after CABG, only the patients without POCD had a decrease of event-related theta activity in the left parietal leads compared with baseline. During the stage of 600-800 ms, the POCD patients had a lower degree of theta-desynchronization of both frontal-central and parietal regions of right hemisphere compared to patients without cognitive decline. Conclusion. The cognitive decline in patients after CABG determined according to neuropsychological testing is accompanied by pathological changes in the event-related theta activity. An analysis of event-related synchronization/desynchronization can be used both as predictor of postoperative cognitive impairment and as objective marker of POCD.

Aim. To study the sex characteristics of cognitive functions in a cohort of patients undergoing coronary artery bypass grafting (CABG) by comparing the results of Mini-mental state examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores.Material and methods. The prospective cohort study included 272 people, including 74 women aged 41 to 82 years, who were admitted to the Research Institute of Complex Issues of Cardiovascular Diseases for CABG surgery. All patients underwent clinical, laboratory, electrophysiological and ultrasound examinations. The Charlson comorbidity index (CCI) was calculated. Assessment of cognitive functions was carried out using the MMSE and MoCA scores. All types of statistical analysis were performed using the STATISTICA 10 program (StatSoft Inc., USA).Results. It was found that women scheduled for CABG have an older age and a higher CCI score compared to men (p=0,008). According to the MMSE, the likelihood of moderate and severe cognitive impairment in men compared with women was 1,36 times higher (odds ratio (OR), 1,35; 95% confidence interval (CI), 0,79-2,32, Z=1,11, p=0,27). The MoCA scores showed that half of the male (49%) and female (50%) participants had severe cognitive impairment. The likelihood of moderateand severe cognitive impairment in men compared with women was 1,33 times higher (OR, 1,33; 95% CI, 0,68-2,59, Z=0,841, p=0,40). According to subtests of the MoCA, men were better in naming (p=0,002), abstraction (p=0,005), and women outperformed men in verbal fluency (p=0,04). Regression analysis revealed that the most significant negative predictors for cognitive status as measured by the MMSE and MoCA scores for men and women were age and CCI.Conclusion. Women scheduled for CABG, having the worst clinical and demographic indicators, are comparable with men in cognitive status using the MMSE score. The MoCA score shows sex differences in naming, abstraction, and verbal fluency domains and revealed a higher percentage of severe cognitive disorders (up to 50%) compared to the MMSE score (7-9%). In male and female candidates for CABG, age and comorbidities are negatively associated with cognitive status.

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Aim. To estimate psychophysiological changes during workspace virtualization.Materials and Methods. We evaluated the psychophysiological profile of 10 healthy right-handed males aged 25 to 45 years before, during and after the working in a virtual reality (VR) headset. All participants had higher education, normal or corrected to normal vision, and were experienced computer users. Psychometric testing included a neurological examination, assessment of functional and feedback-related brain activity (reaction time, errors, and missed signals) and attention span, quantification of processed symbols in the 1st and 4th minutes of Bourdon test, analysis of short-term memory (10 words, 10 numbers and 10 meaningless syllables memorization) and spatial perception, and multi-channel electroencephalography recording in rest.Results. Deterioration of psychometric indicators after a cognitive load in a VR headset was documented only in the most difficult tasks: the number of errors increased by 93% in the brain performance test and by 65% in the attention distribution test. The analysis of electroencephalography data showed that the delta rhythm and theta1 rhythm activity decreased by 28 and 13%, respectively, after working in a VR headset as compared to baseline values, while alpha1 rhythm activity increased by 96%. Probably, the observed electroencephalography changes corresponded to the patterns of brain activation associated with cognitive load and the resulting fatigue.Conclusions. We developed a suitable approach for the psychometric testing before and after working in VR headset, which demonstrated general tolerance and acceptable subjective difficulties to VR load.

Aim. To evaluate the neuropsychological parameters from the main cognitive domains (neurodynamic functions, attention and short-term memory) and the brain electrical activity in patients with non-valve atrial fibrillation (AF).Methods. 21 patients with the mean age of 61 [56; 67] years with non-valve AF who were admitted to the Department of Interventional Diagnosis and Treatment at the Research Institute for Complex Issues of Cardiovascular Disease were included in the study. The control group consisted of 17 healthy individuals with the mean age of 55 [49; 62] years. All patients underwent neuropsychological screening and computerized testing of neurodynamic functions, attention and short-term memory along with electroencephalographic studies. Statistical analysis was performed using the STATISTICA 10.0 software package.Results. Mild cognitive impairment was observed in 43% of patients with non-valve AF accompanied by ischemic brain matter changes according to the findings of magnetic resonance imaging. Patients with AF had slower complex sensorimotor reaction, more errors, worse directed attention, memorization of words and meaningless syllables in comparison with healthy individuals. In addition, patients with AF and healthy subjects had differences in the fronto-occipital gradient of theta-2 rhythm. The worst neurodynamic parameters were associated with a greater power of theta rhythms predominantly in the posterior parts of the brain only in patients with AF.Conclusion. Patients with non-valve AF had cognitive deficit with impaired executive control, attention and short-term memory as well as the slowing of cortical electrical activity in comparison to healthy individuals. The data obtained in our study are beneficial for developing an individual approach to prevent the development and progression of cognitive impairment in patients with AF.