scholarly journals The brain functional activity - bioelectrical marker of the effectiveness of carotid endarterectomy performed in the acute period of ischemic stroke

2017 ◽  
Vol 16 (3) ◽  
pp. 15-20
Author(s):  
I. V. Stafeeva ◽  
I. A. Voznjouk ◽  
I. P. Dudanov
Keyword(s):  
Carotid Endarterectomy ◽  
Spectral Power ◽  
Spectral Characteristics ◽  
Power Spectra ◽  
Beta Activity ◽  
Stroke Severity ◽  
Bioelectrical Activity ◽  
Acute Period ◽  
Before And After ◽  
The Brain

Bioelectrical activity is a universal characteristic of functional state of the brain at a normal level of blood flow and under hypoperfusion. This parameter can be used to assess the effectiveness of the operation before and after endarterectomy. In this study we analyzed spectral characteristics of EEG in 106 patients who underwent endarterectomy in the acute period of stroke before and after two weeks from the onset of the disease. Was studied the dynamics of the power spectra of the EEG evoked potentials and clinical data before and after surgery. It is revealed that the nature of the change in the spectral power of alpha and beta activity of the EEG in the affected and in the intact hemisphere in acute ischaemic stroke can affect the timing of carotid endarterectomy and are important for the prediction of functional outcome after surgery. Inhibition of alpha- and beta-activity in both hemispheres in the preoperative period is an unfavorable factor for surgical intervention, as this will not lead to restoration of disturbed functions irrespective of stroke severity.

BIOELECTRIC ACTIVITY OF THE BRAIN IN PATIENTS WITH ACUTE CEREBROVASCULAR ACCIDENT

Vestnik ◽  
2021 ◽  
pp. 29-34
Author(s):  
Д.А. Митрохин ◽  
М.М. Ибрагимов ◽  
Б.Р. Нурмухамбетова ◽  
Н.Ш. Буйракулова ◽  
В.В. Харченко ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Hemorrhagic Stroke ◽  
Spectral Power ◽  
Spectral Power Density ◽  
Cerebral Stroke ◽  
Beta Activity ◽  
Bioelectric Activity ◽  
Early Recovery ◽  
Coherence Index ◽  
The Brain

Значимость биоэлектрической активности головного мозга в оценке функционального состояния нервной системы при цереброваскулярных заболеваниях широко известна. В настоящей работе показана характеристика биоэлектрической активности головного мозга у больных, перенесших острое нарушение мозгового кровообращения. В данной статье приведены данные о том, что у больных в остром и раннем восстановительном периодах церебрального инсульта биоэлектрическая активность головного мозга характеризовалась, в основном, десинхронным и дезорганизованным типами электроэнцефалограммы. Вместе с тем, отмечались, выраженная дельта и тета активность, а также единичные острые волны, спайки, преимущественно в пораженном полушарии головного мозга, реже в контралатеральном полушарии, межполушарная асимметрия, повышение 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. Результаты исследования относительной спектральной плотности мощности диапазонов показали, что при геморрагическом инсульте отмечена более высокая дельта и бета активность, а также более значительное снижение мощности альфа ритма, в сравнении с ишемическим инсультом. В тоже время, отмечается повышение интегрального индекса диапазона низкочастотной медленно-волновой активности, особенно выраженное у больных с геморрагическим инсультом р<0,05. The significance of bioelectric activity of the brain in assessing the functional state of the nervous system in cerebrovascular diseases is widely known. In this paper, the characteristics of the bioelectric activity of the brain in patients with acute cerebral circulatory disorders are shown. This article presents data that in patients with acute and early recovery periods of cerebral stroke , the bioelectric activity of the brain was characterized mainly by desynchronous and disorganized types of electroencephalogram. At the, same time, pronounced delta and theta activity was noted , as well as single acute waves, spikes, mainly in the affected hemisphere of the brain, less often in the contralateral hemisphere, interhemispheric asymmetry, increased spectral power in the direction of predominance of slow waves. The coherence index values for all leads were reduced, which indicates a violation of functional interhemispheric relationships. A more significant increase in the coherence index in the delta and theta ranges in patients who have had a hemorrhagic stroke may indicate more severe interhemispheric disorders compared to ischemic stroke. The results of the study of the relative spectral power density of the ranges showed, that in hemorrhagic stroke, there was a higher delta and beta activity, as well as a more significant decrease in the power of the alpha rhythm, in comparison with ischemic stroke. At the same time, there is an increase in the integral index of the range of low-frequency slow-wave activity, especially pronounced in patients with hemorrhagic stroke p < 0.05.

scholarly journals Cerebral Metabolism of Patients with Stenosis of the Internal Carotid Artery before and after Endarterectomy

1996 ◽  
Vol 16 (2) ◽  
pp. 320-326 ◽  
Author(s):  
J. van der Grond ◽  
R. Balm ◽  
C. J. M. Klijn ◽  
L. J. Kappelle ◽  
B. C. Eikelboom ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Carotid Endarterectomy ◽  
Internal Carotid ◽  
Cerebral Metabolism ◽  
Control Subjects ◽  
Increased Risk ◽  
Before And After ◽  
Healthy Control ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Occlusion or severe stenosis, with a reduction in the diameter of more than 70% of the extracranial arteries may lead to hypoperfusion of the brain with an increased risk of cerebral infarction. The aim of this study was to investigate whether endarterectomy of stenosed internal carotid arteries leads to alterations in cerebral metabolism in regions in which no infarcts were visible with magnetic resonance imaging (MRI). We studied 10 healthy control subjects and 20 patients with transient or nondisabling cerebral ischemia with MRI and 1H magnetic resonance spectroscopic imaging. All patients underwent carotid endarterectomy. Patients were examined 1 week before and 3–6 months after carotid endarterectomy. The N-acetyl aspartate (NAA)/choline ratio in the symptomatic hemisphere before endarterectomy (2.29 ± 0.42) was significantly ( p < 0.001) lower than for control subjects (3.18 ± 0.32). In five of the patients lactate was detected preoperatively in regions that were not infarcted. The NAA/choline ratio in the symptomatic hemisphere of these five patients did not increase significantly after endarterectomy (1.99 ± 0.22 vs. 2.23 ± 0.48). The NAA/choline ratio in patients without lactate preoperatively increased significantly ( p < 0.01) after endarterectomy to a normal level (from 2.39 ± 0.42 to 2.92 ± 0.52). These results indicate that the presence of cerebral lactate may predict whether the NAA/choline ratio increases after carotid endarterectomy.

CHARACTERISTICS OF THE BRAIN ELECTRIC ACTIVITY IN COGNITIVE IMPAIRMENT

2021 ◽  
Author(s):  
O. E. Dik ◽  
Keyword(s):  
Cognitive Impairments ◽  
Electric Activity ◽  
Bioelectrical Activity ◽  
Recurrence Plots ◽  
Functional Brain ◽  
Functional Load ◽  
Before And After ◽  
Quantitative Indicators ◽  
The Brain ◽  
Brain Connections

Based on the analysis of joint recurrence plots of the brain’s response to functional load in the form of rhythmic photostimulation, quantitative indicators of changes in the bioelectrical activity of the brain of patients with moderate cognitive impairments were revealed before and after the method of therapy associated with the formation of stable functional brain connections. It has been shown that such therapy, leading to an improvement in the condition of patients, correlates with changes in the indicators of joint recurrence plots of the bioelectrical activity of the brain and photostimulus.

Broad-band spectral analysis of 24 h continuous finger blood pressure: comparison with intra-arterial recordings

1999 ◽  
Vol 97 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Paolo CASTIGLIONI ◽  
Gianfranco PARATI ◽  
Stefano OMBONI ◽  
Giuseppe MANCIA ◽  
Ben P. M. IMHOLZ ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spectral Power ◽  
Spectral Characteristics ◽  
Broad Band ◽  
Systolic Pressure ◽  
Power Spectra ◽  
Night Time ◽  
Non Invasive ◽  
Spectral Estimates ◽  
Band Spectra

The present study compares the spectral characteristics of 24-h blood pressure variability estimated invasively at the brachial artery level with those estimated by measurement of blood pressure at the finger artery using the non-invasive Portapres device. Broad-band spectra (from 3×10-5 to 0.5 Hz) were derived from both finger and intra-brachial pressures recorded simultaneously for 24 h in eight normotensive and twelve hypertensive ambulant subjects. At frequencies lower than 0.07 Hz, higher spectral estimates were obtained by Portapres than by intra-brachial measurements. The maximum overestimation occurred in systolic pressure at around 10-2 Hz, where the amplitude of the oscillations was two times greater when measured by Portapres. A less pronounced overestimation was found for diastolic pressures. The maximum overestimation was greater during daytime than during night-time. At around 0.1 Hz, invasive and non-invasive spectra were similar. At the respiratory frequencies (0.15-0.50 Hz), the power spectra were overestimated by Portapres during daytime, and underestimated at night. These results provide reference information for the correct interpretation of Portapres data in the estimation of 24-h blood pressure spectral power.

scholarly journals NEUROPHYSIOLOGICAL EVALUATION OF THE EFFECTIVENESS OF EARLY CAROTID ENDARTERECTOMY IN ATHEROTHROMBOTIC STROKE

2020 ◽  
Vol 178 (6) ◽  
pp. 10-17
Author(s):  
I. V. Stafeeva ◽  
I. P. Dudanov ◽  
I. A. Voznjouk ◽  
S. V. Ordinec ◽  
V. V. Ahmetov
Keyword(s):  
Evoked Potentials ◽  
Carotid Endarterectomy ◽  
Postoperative Period ◽  
Somatosensory Evoked Potentials ◽  
Carotid Arteries ◽  
Surgical Intervention ◽  
Brain Activity ◽  
Prognostic Significance ◽  
Power Spectra ◽  
Acute Period

INTRODUCTION. At present, the advantages of surgical treatment over conservative methods in patients with hemodynamically significant stenosis of the carotid arteries are actively discussed. Nowadays, the main discussion issues are the time from the beginning of the stroke to the operation and the criteria for selecting patients for surgical intervention. In recent years, neurophysiological methods for studying spontaneous and evoked brain activity, which are able to identify functional disorders that have important prognostic significance, have become the most relevant.OBJECTIVE. To study the dynamics of spectral-coherent parameters of EEG and somatosensory evoked potentials in patients with ischemic atherothrombotic stroke of different severity, who were performed carotid endarterectomy on the heart attack side in an acute period.METHODS AND MATERIALS. We examined 105 patients with ischemic stroke who underwent carotid endarterectomy in the acute period, analyzed the dynamics of spectral, coherent characteristics of EEG and amplitude-latency parameters of somatosensory evoked potentials in the postoperative period.RESULTS. The dynamics of power spectra, intra-hemispheric EEG, latency and amplitude of somatosensory evoked potentials and clinical parameters were compared.CONCLUSION. It is shown that significant suppression of alpha activity power on the side of both hemispheres, decrease of intra-hemispheric coherence and amplitude of N20-P23 on the side of clinically intact hemisphere in the period up to 3 weeks after surgery determines a longer recovery of neurological deficit in the postoperative period. 

scholarly journals Electrical activity dynamics of the hippocampus under caffeine influence

2014 ◽  
Vol 25 (3-4) ◽  
pp. 107-113
Author(s):  
T. G. Turitskaya ◽  
A. G. Sidorenko
Keyword(s):  
Electrical Activity ◽  
Adenosine Receptors ◽  
Spectral Power ◽  
Biological Effects ◽  
White Male ◽  
The Body ◽  
Male Rats ◽  
Bioelectrical Activity ◽  
Wide Range ◽  
The Brain

Multiple studies have shown that the hippocampus is a major part of the limbic system of the brain. It has complex cyclic connections with other brain structures. The hippocampus is an area that stores the sensory information that is associated with effective programs of behavior. The projection of this region in the cortex creates a sense of emotional background, which is a factor of automatic extraction and evaluation of programs, in accordance with past experience, including programs got with a new consciousness. Neurons of hippocampus differ with a severe background activity. Up to 60% of neurons in the hippocampus are responding on the sensory stimulation. Electrical activity is a manifestation of complex shape analyzer processes in stimulating tissues. Changes in activity may indicate the occurrence of adaptive processes that are the result of stress- realizing and stress- limiting systems. One of the main roles in these systems plays hippocampus. The main neurotransmitters of synaptic stimulation in the hippocampus are glutamate. In the hippocampus under conditions of chronic stress are developing neurodegenerative processes in which primary importance belongs to prolonged changes in membrane potential of neurons that potentiate the action of glutamate on nerve cells. Balanced job of synaptic stimulation/inhibition and neurotransmitters systems is underlying the transmission, processing and storage of information in the hippocampus, as well as generating its rhythms, which is a kind of clock operating frequencies of the structure of the brain. Obviously, the various factors that affect the body from the outside can affect on recovery efficiency of electric shift of homeostasis. One of such factors are caffeinated substances, due to their inhibitory effect on phosphodiesterase and interaction with the purine receptors, which ultimately leads to the predominance of stimulating in the brain. In addition, for many decades consumption of caffeinated products with neuro-stimulating properties have greatly increased. Leaders in this list remain coffee and tea. Today the well-known biological effects of caffeinated substances are investigated their chemical composition and process of the transformation in the body. The wide range of research is due to the high consumption of these substances. The environmental factors indirectly or directly, in combination or single affect health, and the caffeinated substances can go to one of the best in strength and impact performance. In neurochemical mechanism of stimulating effect of caffeine plays an important role its ability to bind to specific ("purine" or adenosine) receptors in the brain, the endogenous ligand for which is purine nucleoside – adenosine. The structural similarity of molecules of caffeine and adenosine contributes to this. Since adenosine is seen as a factor that reduces the stimulating processes in the brain, replacing its caffeine results in stimulative effect. Prolonged use of caffeine promotes the formation of new adenosine receptors and the effect of caffeine gradually decreases. However, the sudden cessation of caffeine consumption, adenosine covers all receptors that may lead to increased inhibition with symptoms of fatigue, sleepiness, depression. The relevance of this work is determined by the following observations. Activating mechanism of action of these substances is launching adaptive responses that represent the interaction stress-activating and stress-limiting systems. Energy shortage of the last one under these conditions can appear the cause of many neurodegenerative patalohiy. What may occur in terms of the electroencephalogramm. Electrical activity of the hippocampus, in turn, is one of the indicators of the functional state, which plays an important role in adaptive-compensatory reactions. Therefore, we can assume that prolonged consumption of caffeinated substances can lead to neurodegenerative changes that will show itself in terms of power on hippocampogramm. Therefore, the present study has to identify the dynamics of the bioelectrical activity of the hippocampus of rats under prolonged consumption of caffeinated substances. Experiments were carried out on non-linear white male rats. At the beginning rats were with weight 125–140 g. The animals were divided into 2 groups. The first group consisted of control animals (n = 20). The second group (n = 15) was presented by the animals feeded with pure caffeine in an amount of 150 mg/kg/day. Registration of electrohippocampogramm was performed in acute experiments in the subgroup of 3–5 animals every 2 weeks throughout the study, which lasted for 8 weeks. Background electrical activity of the hippocampus were recorded using standard electrophysiological complex equipment. Recordings started when the electrical activity of the hippocampus disappeared drugs spindle. Each animal spent 10–12 records for 1–2 minutes and then these records are digitally stored on a personal computer and processed using the application package consisting of "MathCAD 2001". Analyzed spectral power (mkV2) and normalized power (%) waves of background electrical activity of the hippocampus within common frequency bands. In the group of animals that continued to receive caffeine in its pure form at the beginning of experiment was observed desynchronization of rhythms in hippocampogramm that after 8 weeks of the study varied synchronization. The results may indicate that the effect of coffeine substances on neurophysiological parameters of electrical activity of the hippocampus of rats reflects one of the many lines of action of some form of nutritional stress, which mechanisms relate to the agreed work and limiting and activating systems of the brain over time.

scholarly journals NEUROPHYSIOLOGICAL MECHANISMS OF LOGONEUROSIS IN PRESCHOOL CHILDREN DURING FUNCTIONAL STRESS

2020 ◽  
Vol 2020 (3) ◽  
pp. 13-19
Author(s):  
Nataliia Vasylieva
Keyword(s):  
Preschool Children ◽  
Electrical Activity ◽  
Spectral Power ◽  
Low Frequency ◽  
Bioelectrical Activity ◽  
Subcortical Structures ◽  
Zonal Distribution ◽  
Neurophysiological Mechanisms ◽  
The Brain ◽  
Functional Stress

The changes in the electrical activity of the brain of boys with different tempo-rhythmic characteristics of speech during functional stress have been studied, namely, a series of flashes of light of a certain frequency – rhythmic photostimulation have been used. The bioelectrical activity of the brain has been studied using a computer electroencephalography system. Also, according to the methodology of zonal distribution of normalized spectral power (SP) of the rhythm of the main frequency of the EEGranges, the particles (in percent) of the normalized SP of electrogenesis in each of the four main ranges (δ, θ, α, β) have been determined. As a result of comparison of the light flashing frequency assimilation among boys in the studied groups, it has been found, that in the group of children with logoneurosis slow rhythms (5 Hz,) lying within the theta-range of the EEG, were better assimilated. The rhythm is assimilated in the low frequency range among the children with logoneurosis. The relative spectral power of theta-rhythm significantly decreased on the EEG of children with tempo and rhythm speech disorder at low-frequency photostimulation in comparison with the corresponding indicators of the background electroencephalogram; the corresponding indicators in the beta-range, anterior and posterior leads in the alpha-rangeincreased. Based on the obtained data, it has been found, that children with logoneurosis have insufficient response to photostimulation. Such data are associated with insufficient inhibitory effect of the cortex on the subcortical structures. The reduced reactivity and functional insufficiency of the activating system of the brain stem have been noted. Neurophysiological mechanisms of logoneurosis are due to the state of insufficient formation of brain structures, which is confirmed by the results of electroencephalography during rhythmic photostimulation. Changes in the tempo and rhythm of speech during logoneurosis of preschool children provoke stress of the brain mechanisms of regulation, which become apparent by special characteristics of the electrical activity of the brain, both at rest and during load.

The magnetic activity distribution in the brain before and after carotid endarterectomy

1994 ◽  
Vol 39 (s1) ◽  
pp. 131-132
Author(s):  
Helmut Kober ◽  
Viktor Bujanowski ◽  
Peter Grummich ◽  
Dirk Ulbricht ◽  
Claudia Brigel ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Magnetic Activity ◽  
Activity Distribution ◽  
Before And After ◽  
The Brain

scholarly journals Clinical and neurophysiological features of mental disorders in patients with HIV infection

2019 ◽  
pp. 53-63
Author(s):  
N. G. Neznanov ◽  
N. B. Khalezova ◽  
M. A. Hobeysh ◽  
N. G. Zakharova ◽  
M. Ya. Kissin
Keyword(s):  
Mental Disorders ◽  
Hiv Infection ◽  
Cross Sectional Study ◽  
Beta Activity ◽  
Bioelectrical Activity ◽  
Cross Sectional ◽  
And Control ◽  
Organic Syndrome ◽  
The Brain ◽  
Adaptive Reactions

Summary.Te aim of the study was to study the clinical signifcance of changes in bioelectric activity for the purpose of identifying them as biological markers of mental disorders in patients with HIV infection. A cross-sectional study was conducted to diagnose mental disorders and search for neurophysiological markers in 62 patients with HIV infection at the St. Petersburg Center for the Prevention and Control of HIV and Infectious Diseases.Results: 50% of patients with HIV infection without abuse disorders have mental disorders characterized mainly by adaptive reactions and mild cognitive impairment. Normal indicators of bioelectrical activity were determined in 16.1% of 62 patients. In the majority of patients (59.7%), bioelectrical activity was determined with a predominance of excitation in the medio-different areas and a decrease in activity of the cerebral cortex. In 41.9% of patients, the processes of CNS excitation were increased in the form of an intensifcation of the reaction to photostimulation. Neurophysiological differences were revealed in patients with neurotic and stress-related disorders and organic changes in the CNS. For neurotic disorders in comparison with organic disorders, the EEG was normal or the disorganized type with predominance of alpha and beta activity were more likely, while in the case of organic disorders the desynchronous type of EEG was more ofen noted. Te development of psycho-organic syndrome in HIV patients is confrmed by deep restructuring of bioelectrical activity in the anterior parts of the brain.

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