Vol 44, No 6 (2018)

The relationship between individual characteristics of spontaneous electrical activity of the brain and concentration of attention was studied using the analysis of accuracy in the “Bourdon test” for voluntary attention. The accuracy of test performance was found to correlate with the spectral power and index of the α and θ bands in the left mid-temporal cortical area, as well as an increase in signal connectivity between the mid-temporal and other EEG sites. An increase in the spectral power of the θ band and a decrease in α index led to an increase in the number of errors in the test. On the one hand, the findings possibly indicate that the left mid-temporal region plays a special role organizing the coordinated systemic spatiotemporal interaction of cortical fields, which is necessary for efficient test performance. On the other hand, the findings raise the question as to whether a reorganization of background brain activity is of importance as a precondition of local processes to facilitate further cognitive performance.

We analyzed the relationships between the EEG spectral parameters in depressed patients reflecting the functional state of the brain, and the efficiency of their decision-making based on both logic and emotional learning in order to clarify the neurophysiological mechanisms underlying decision-making impairments. As a result of multivariate cluster analysis based on 96 EEG spectral power parameters, two subgroups of depressive patients were identified. The groups differ in the EEG amplitude-frequency and spatial characteristics, but do not differ either in age or in severity of depression. The subgroup of depressive patients who formed cluster 2 and had higher spectral powers of the EEG ∆ (2–4 Hz), θ₁ (4–6 Hz), θ₂ (6–8 Hz), α₁ (8–9 Hz) and α₂ (9–11 Hz) subbands, as compared with the patients who formed cluster 1, had a higher level of cognitive test performance that requires decision-making: the Wisconsin Card Sorting Test (WCST), which evaluates logic-based decision-making, and the Iowa Gambling Task (IGT), which evaluates decision-making based on emotional learning. Cluster 2 patients also exhibited a better long-term memorization (in the ten-word long-term memory test) compared with those who formed cluster 1. Judging by the EEG parameters, the neurophysiological mechanisms of inhibition are more intact in patients forming cluster 2 than in cluster 1 patients who have lower spectral power values of the EEG ∆ (2–4 Hz), θ₁ (4–6 Hz), θ₂ (6–8 Hz), α₁ (8–9 Hz), and α₂ (9–11 Hz) subbands. The impairment of decision-making functions in depressive patients may, at least partially, be due to the deficit of the brain inhibition mechanisms that ensure normal integrative brain activity, including such higher mental functions as memory, attention, and decision-making.

The precedence effect is a phenomenon characterizing the noise stability of the auditory system in localizing a sound source. This phenomenon is based on the ability of the auditory system to localize a direct sound in an environment of masking acoustic reflections coming from various surfaces. To create the precedence effect, we used two signals: the first was a direct signal (the lead) and the second one arriving at a delay relative to the onset of the lead was an echo signal (the lag). The signals were presented in the horizontal plane. Their duration was 1 s. Delays between the onset of the lag and that of the lead ranged from 1 to 40 ms. The suppression of the moving lag was compared in the study with that of the stationary lag. The movement of the lag was created along two paths located to the left from the subject’s head midline in the horizontal plane (–86°...–52° and –52°...–18°). The stationary lag was located at the ends of these two paths. The lag movement was simulated in opposite directions (either approaching or distancing from the lead signal). The lead was always stationary and located to the right from the head midline in the horizontal plane (15°). The lag suppression was estimated by echo suppression threshold values. It has been shown for the stationary lag that the nearer the lag was located to the lead the higher the lag was suppressed and the mean echo suppression threshold values increased from 5.1 to 7.1 ms. The location and the direction of movement of a travelling lag did not affect its suppression. The mean threshold values ranged from 6.2 to 6.9 ms. Individual differences between the threshold values were greater with moving signals than with stationary ones.

Neuromuscular electrical stimulation (NMES) of large muscle groups in patients with stable chronic heart failure (CHF) increases physical work capacity and muscle strength. The safety and efficacy of short courses of NMES in patients with decompensated CHF has not been studied. The aim of the study was to compare the impact of leg NMES, interval bicycle training, and conventional treatment on the functional capacity and quality of life in patients hospitalized with decompensation of CHF. A total of 51 patients (84.3% of men; mean age, 62.5 ± 3.3 years) hospitalized with decompensated CHF were divided into three groups: optimal pharmacological therapy (OPT) + three weeks of NMES of thigh and shin muscles starting within the first three days after admission (n = 10), OPT + three weeks of bicycle exercise training (BET) starting on the fifth to seventh day (n = 20), and the control group of OPT only (n = 21). At baseline and after the three-week symptom-limited cardiopulmonary exercise test, 6-min walk test, Duke Activity Status Index (DASI) and quality of life assessment by the Minnesota Living with Heart Failure Questionnaire (MLHFQ) were performed. Patients in the NMES and BET groups presented with similar increases in the 6-min walk distance, plus 65.0 (50.0; 112.5) and 53.0 (51.0; 78; 0) m; DASI, plus 8.6 (5.5; 11.8) and 8.0 (4.5; 9.0) points; and VO_2peak, plus 1.9 (0.3; 3.2) and 2.2 (0.7; 3.2) mL/(min kg), respectively. In the control group, only the 6-min walk distance increased significantly (+21 m). The improvement in the MLHFQ score was observed in all the three groups: maximal in the BET group and minimal in the NMES group. Three weeks of leg muscle electrical stimulation and bicycle training provide similar improvement in physical capacity, daily activity, and the quality of life in patients hospitalized for severe CHF. The efficacy of NMES is comparable with low to moderate intensity interval bicycle training and well tolerated by patients.

The indices of the system of endogenous regulation of nitric oxide (NO) bioavailability of were compared in the group of athletes and the control group of subjects with a sedentary lifestyle. The concentrations of L-arginine (as a substrate of NO synthase and arginase) and its methylated derivatives monomethylarginine and asymmetric and symmetric dimethylarginines (MMA, ADMA and SDMA) in the blood were measured using high performance liquid chromatography (HPLC) with fluorescent detection. In parallel, some common biochemical blood parameters and the total antioxidant status were evaluated. The concentration of L-arginine in the blood plasma of athletes was 24% higher than the concentration in the control group. The levels of ADMA and SDMA were lower by 39 and 80%, respectively. The MMA level was almost two times higher than that in the control group. The total protein, bilirubin, total cholesterol, and triglyceride levels were significantly lower in athletes compared with the control. Interesting significant correlations were found between L-arginine and urea in the control group and between the Arg-to-ADMA ratio and the antioxidant activity index in the group of athletes.

The loss of limbs or limitations to their motor functions leads to a critical deterioration of the human quality of life. This article presents a brief review about the evolution of prosthetics, the dawn of which dates back to antiquity, and shows its transition to new technologies between the two world wars and in the contemporary era. The authors discuss the interfaces developed for controlling the recovery of lost limb functions, based on the optimal choice of assistive devices and artificial bypassing from the brain to the spinal cord with a closed feedback loop. The review gives the current classification and application of control interfaces (both invasive and noninvasive) for the recovery of functions, using electroencephalogram (EEG) components (including brain–computer interfaces (BCIs)), as well as electrical and other myogram components. The interfaces are discussed in terms of changes in the physical characteristics of muscles during their contraction and vibration and other properties. The article considers challenges and global demands for specialized treatment as exemplified by American statistical data on spinal cord lesions.

Currently, antipsychotics are the only type of drugs for the treatment of schizophrenia. The efficacy of antipsychotics in the treatment of schizophrenia is unsatisfactory. Specifically, more than 20% of schizophrenia patients are antipsychotic-resistant patients not sensitive to at least two antipsychotics. A combination of factors affecting the drug metabolism (pharmacokinetics) and the drug action (pharmacodynamics) underlies the differences in the response to the same antipsychotic agent. There is an obvious genetic contribution to the variability of response to psychotropic agents. Moreover, it is known that side effects caused by administration of these drugs may have an even stronger genetic component. This review presents the results of the most recent world research in the field of pharmacogenetics of antipsychotics.

The purpose of this pilot study was to investigate the association of five polymorphic loci of the DRD2 gene (rs1799732, rs1800497, rs6277, rs6275, and rs2242592) with antisaccade task performance in male cohorts of schizophrenic patients (n = 33) and healthy subjects (n = 30). The antisaccade error rate was analyzed as related to prefrontal inhibitory control. In patients, the increased percent of errors was associated with minor alleles of polymorphisms rs6277 (C), rs6275 (T), and rs2242592 (G), which are supposedly related to the risk of schizophrenia. At the same time, it was found that a decreased error rate in healthy subjects is associated with the C/C variant of rs6277; no association was observed between polymorphisms rs6275 and rs2242592 and task performance.