scholarly journals Manganese encephalopathy and interhemispheric asymmetry of the brain

Author(s):  
L. Berezovchuk ◽  
M. Makarchuk

Patients suffering from manganese encephalopathy, which develops while taking surrogate drugs, suffer from pronounced subcortical pseudobulbar syndrome, pyramidal insufficiency and a complex of autonomic disorders. The most pronounced of them are disorders of motor functions. The work is devoted to the study of the bioelectrical activity of the brain of patients with manganese encephalopathy in order to develop an EEG-criterion for diagnosing this disease. The subjects underwent EEG recording using a 16-channel electroencephalograph "NeuroCom standart" (KhAI-Medika, Ukraine) in accordance with the international recording system "10-20". The following were analyzed: the power of the signals of the main rhythms of the background EEG, the relative characteristics of the power of the signals of the main EEG rhythms – the activation coefficient of the cortex, the activation coefficient of the sub cortex, the indices of interhemispheric asymmetries in terms of the power of bioelectric signals in bilaterally synchronous points of the head. It was found that in patients with manganese encephalopathy both the cortical activation coefficients and the sub cortex activation coefficients had values that can be observed in patients with аnother diseases. In turn, such indicators as interhemispheric asymmetry in the power of signals of individual rhythms and interhemispheric asymmetry in the total power of signals at bilaterally synchronous points of the head in patients with manganese encephalopathy had values that significantly differed from those in patients with other types of pathology. So, with indicators of 16-18 interhemispheric asymmetries in healthy people and 9-25 in patients in coma, in patients with manganese encephalopathy, it was observed: in one patient – 12 interhemispheric asymmetries, in the other of the patients – 9, 7, 3 and 2 interhemispheric asymmetries in signal power of individual rhythms at bilaterally synchronous points of the head. The reason for such a pronounced smoothing of interhemispheric asymmetries in patients with manganese encephalopathy, obviously, may be those destructive changes in the subcortical parts of the GM that are present in this group of patients.

Author(s):  
Yuliya S. Dzhos ◽  
◽  
Irina A. Men’shikova ◽  

This article presents the results of the study on spectral electroencephalogram (EEG) characteristics in 7–10-year-old children (8 girls and 22 boys) having difficulties with voluntary regulation of activity after 10 and 20 neurofeedback sessions using beta-activating training. Brain bioelectric activity was recorded in 16 standard leads using the Neuron-Spectrum-4/VPM complex. The dynamics was assessed by EEG beta and theta bands during neurofeedback. An increase in the total power of beta band oscillations was established both after 10 and after 20 sessions of EEG biofeedback in the frontal (p ≤ 0.001), left parietal (p ≤ 0.036), and temporal (p ≤ 0.003) areas of the brain. A decrease in the spectral characteristics of theta band oscillations was detected: after 10 neurofeedback sessions in the frontal (p ≤ 0.008) and temporal (p ≤ 0.006) areas of both hemispheres, as well as in the parietal area of the left hemisphere (p ≤ 0.005); after 20 sessions, in the central (p ≤ 0.004), frontal (p ≤ 0.001) and temporal (p ≤ 0.001) areas of both hemispheres, as well as in the occipital (p ≤ 0.047) and parietal (p ≤ 0.001) areas of the left hemisphere. The study into the dynamics of bioelectric activity during biofeedback using EEG parameters in 7–10-year-old children with impaired voluntary regulation of higher mental functions allowed us to prove the advisability of 20 sessions, as the increase in high-frequency activity and decrease in low-frequency activity do not stop with the 10th session. Changes in these parameters after 10 EEG biofeedback sessions are expressed mainly in the frontotemporal areas of both hemispheres, while after a course of 20 sessions, in both the frontotemporal and central parietal areas of the brain.


Vestnik ◽  
2021 ◽  
pp. 46-50
Author(s):  
Д.А. Митрохин ◽  
М.М. Ибрагимов ◽  
А.Н. Симбинова ◽  
Н.Ш. Буйракулова ◽  
В.В. Харченко ◽  
...  

В остром и раннем восстановительном периодах церебрального инсульта взаимосвязь между биоэлектрической активностью головного мозга и клинической картиной заболевания представляют значительный научный и практический интерес. В данной статье, представлены результаты исследования клинико-неврологических и электроэнцефалографических показателей, в остром и раннем восстановительном периодах церебрального инсульта, 67 больных в возрасте от 43 до 78 лет. Показано, что у больных в остром и раннем восстановительном периодах церебрального инсульта на фоне двигательных и речевых расстройств, наблюдались легкие и умеренные когнитивные нарушения, а также тревожно-депрессивные проявления. Головная боль, соответствующая критериям головной боли напряжения отмечалась у 61,1% больных. Биоэлектрическая активность головного мозга характеризовалась выраженной дельта и тета активностью, а также единичными острыми волнами, спайками, преимущественно в пораженном полушарии головного мозга, межполушарной асимметрией, повышением мощности спектров в сторону преобладания медленных волн. Показатели индекса когерентности по всем отведениям были снижены, что свидетельствует о нарушении функциональных межполушарных взаимосвязей. Более значительное повышение индекса когерентности в дельта и тета диапазонах у пациентов, перенесших геморрагический инсульт, может указывать на более грубые межполушарные нарушения, в сравнении с ишемическим инсультом. In the acute and early recovery periods of cerebral stroke, the correlation between bioelectrical activity of the brain and the clinical picture of the disease is of considerable scientific and practical interest. This article presents the results of a study of clinical, neurological and electroencephalographic parameters, in the acute and early recovery periods of cerebral stroke, in 67 patients aged from 43 to 78. Mild and moderate cognitive impairment as well as anxiety and depressive manifestations were shown among patients in the acute and early recovery periods of cerebral stroke amid the motor and speech disorders. Headache meeting the criteria of tension headache was reported among 61,1% of patients. The bioelectrical activity of the brain was characterised by marked delta and theta activity as well as single sharp waves, commissures mainly in the affected cerebral hemisphere, interhemispheric asymmetry and by increase in the spectrum power towards the predominance of slow waves. The coherence index scores were decreased on all directions, indicating impaired functional interhemispheric connectivity. A greater increase in coherence index in the delta and theta bands among haemorrhagic stroke patients may indicate more severe interhemispheric disturbances compared to ischaemic stroke.


2020 ◽  
Vol 87 (7-8) ◽  
pp. 53-57
Author(s):  
L. V. Berezovchuk ◽  
M. E. Makarchuk

Objective. Elaboration of objective quantitative criterion of electroencephalogram for estimation of the brain functional state in man. Маterials and methods. The background electroencephalograms analysis was conducted in 6 groups of the examined patients with various diagnosis (41 patients at all). Control group consisted of 7 patients, ageing 20 - 56 yrs (average age 35 yrs). Recording of EEG was conducted, using 16-channel electroencephalograph «NeuroCom standart» (KhАI - Меdika, Ukraine) in accordance to international system of recording «10-20». There were analyzed a quantity of meaningful interhemispheric asymmetries in accordance to power of summarized bioelectric signal in bilateral-synchronous points of the head in every group. The analysis time have constituted 1 min. Results. There was established, that the least meaningful difference in accordance to the bioelectrical signal power in bilateral-synchronous points of head may be considered in 1.4 times. Quantity of meaningful interhemispheric asymmetries in man may vary in large diapason - from 9 tо 25. Not all meaningful interhemispheric asymmetries in accordance to power of signals of separate rhythms are preserved while doing analysis of meaningful interhemispheric asymmetries in accordance to power of a summarized bioelectrical signal. Interhemispheric asymmetries in accordance to power of the summarized bioelectric signal in bilateral-synchronous points of the head may have more important informative meaning, than interhemispheric asymmetry in accordance to the signals power of separate rhythms. Conclusion. Quantity of meaningful interhemispheric asymmetries in accordance to power of signals of separate rhythms in healthy persons may vary from 16 tо 18. The interhemispheric asymmetries quantity reduction in accordance to power of the summarized bioelectric signal, comparing with quantity of interhemispheric asymmetries in accordance to power of signals of separate rhythms more than in 4 times, witnesses presence of the brain bioelectrical buffer system.


2019 ◽  
Vol 69 (1) ◽  
pp. 116-119
Author(s):  
R.A. Kudrin ◽  
◽  
E.V. Lifanova ◽  
A.V. Plotnikova ◽  
◽  
...  

2021 ◽  
Vol 11 (11) ◽  
pp. 249-265
Author(s):  
B. Lobasyuk ◽  
L. Bartsevich ◽  
A. Zamkovaya

Justification. Mental retardation is a persistent decrease in human cognitive activity against the background of organic damage to the central nervous system. Neurophysiological diagnostics, in particular electroencephalography (EEG), most adequately reflects the morpho-functional state of the central nervous system, which is the basis of the mechanisms of mental activity, and the originality of the bioelectrical activity of the brain can be considered as the main indicator that determines a decrease in the level of intellectual development and, thereby, characterizes this state. This provision actualizes the search for highly informative indicators of the originality of the bioelectrical activity of the brain in children with intellectual disabilities. Purspose. With the use of periodometric analysis investigate EEG’s indicators and interhemispheric asymmetry of rhythms amplitudes in MR patients. Materials and methods. The EEG was recorded in a state of calm wakefulness with closed eyes with Neuron-Spectrum-2 electroencephalograph. Differences in indicators were tracked using the calculation of the coefficient of compliance (CC), EEG functional asymmetry coefficients in amplitude were determined, too. Results. It was revealed that in MR patients the amplitudes of the rhythms were greater than in healthy subjects. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. Duration indices in the delta, theta and alpha ranges of the EEG in mental retardation compared with the control group were increased, and the indices of the duration of beta rhythms - decreased. When analyzing FMPA in MR persons it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices. Conclusions 1. With mental retardation, the amplitudes of the rhythms were greater than in healthy people. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. 2. The indices of duration in the delta, theta and alpha ranges of the EEG of MR subjects were increased, and the indices of the duration of beta rhythms – decreased. 3. When analyzing FMPA in MR persons, it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices.


2001 ◽  
Vol 86 (4) ◽  
pp. 1764-1772 ◽  
Author(s):  
Yin Fang ◽  
Vlodek Siemionow ◽  
Vinod Sahgal ◽  
Fuqin Xiong ◽  
Guang H. Yue

Despite abundant evidence that different nervous system control strategies may exist for human concentric and eccentric muscle contractions, no data are available to indicate that the brain signal differs for eccentric versus concentric muscle actions. The purpose of this study was to evaluate electroencephalography (EEG)-derived movement-related cortical potential (MRCP) and to determine whether the level of MRCP-measured cortical activation differs between the two types of muscle activities. Eight healthy subjects performed 50 voluntary eccentric and 50 voluntary concentric elbow flexor contractions against a load equal to 10% body weight. Surface EEG signals from four scalp locations overlying sensorimotor-related cortical areas in the frontal and parietal lobes were measured along with kinetic and kinematic information from the muscle and joint. MRCP was derived from the EEG signals of the eccentric and concentric muscle contractions. Although the elbow flexor muscle activation (EMG) was lower during eccentric than concentric actions, the amplitude of two major MRCP components—one related to movement planning and execution and the other associated with feedback signals from the peripheral systems—was significantly greater for eccentric than for concentric actions. The MRCP onset time for the eccentric task occurred earlier than that for the concentric task. The greater cortical signal for eccentric muscle actions suggests that the brain probably plans and programs eccentric movements differently from concentric muscle tasks.


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