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Biomedical subjects

O M Grindel'

Publications and source records attributed to O M Grindel'.

At least 19 recordsLinked to original sources
PubMed1985

[Recovery of consciousness after prolonged coma in patients with severe craniocerebral injuries].

The authors specify and describe 7 stages of regaining consciousness by patients who had been in coma from 11 to 180 days, including opening of the eyes; fixation of the eyes on an object; recognition of close relatives; understanding of directly addressed speech; patient's own speech; amnestic confusion; consciousness with all formal signs of being clear. The condition of the patients at these stages is compared with EEG findings suggestive of the functional disintegration of the brain as a system in comatose patients, the vegetative status and the restoration of connections between different departments of the brain corresponding to the recovery of long absent consciousness of patients. It is concluded that at the current stage of medical sciences the maximum duration of coma compatible with the subsequent full recovery of mental activity of the patient under 30 years does not exceed 11 days.

Adolescent↗
PubMedDate not supplied

[Peculiarities of changes in the EEG in the development of coma in patients with a focal injury of the brain].

A number of new electrographic variants reflecting the specifity distinguishing the evolution of coma in focal affections of the brain and clearly correlating with its clinical manifestations were elicited. The comatose status, apart from a fall of the level and frequency of the brain biopotentials, is shown to be characterized by an imbalance of spatial and temporal relations in the cortex of the large hemispheres, a correlation between the degree of disrupted inter-central relations and the stage marking the development of the comatose process having been disclosed. Some EEG findings were obtained that may be taken advantage of in judging about the prognosis as to the evolution of coma. An electroencephalographic investigation of the comatose states in focal lesions of the brain opens up the possibilities for a differential approach to the study of coma.

Adult↗
PubMedDate not supplied

[Intercentral EEG relationships in regressive and chronic post-traumatic Korsakoff syndrome].

Dynamic EEG study of patients with posttraumatic Korsakoff's syndrome (KS) with the application of complex analysis methods revealed a complicated pathological structure of the intercentral relations of cortical electrical activity. The interhemispheric EEG coherence between symmetrical frontal cortical areas are sharply reduced, while the intrahemispheric coherence are increased in comparison with the normal values. The proposed technique of segregation of statistically homogeneous spectro-coherent characteristics made it possible to reveal the earlier intercentral EEG relations formed by stable and variable coherence spectra. The structure formed by the stable and variable coherence spectra in KS differs from that reflected in the mean coherence levels. During the KS regression, the EEG coherence between the right and left frontal areas increased to the normal level, and the variable spectra are revealed. In the chronic KS syndrome, the pathological intercentral relations persist, while the variable relations in the frontal areas are absent. A reduction of pathologically decreased intrahemispheric coherence selectively revealed in the right hemisphere during the KS regression and formation of variable relations in this hemisphere point to a leading role of the right hemisphere in development of compensatory processes in KS. The reciprocal relations between the intra- and interhemispheric coherence and coherence dynamics in the theta rhythm suggest that pathological activity in the basal diencephalic structures plays an important role in formation of the pathological EEG pattern in KS.

Chronic Disease↗
PubMedDate not supplied

[The spatial structure of the alpha rhythm in the healthy human being studied by EEG mapping].

EEG study was conducted in the state of relative rest in 15 healthy subjects with predominance of the alpha rhythm. Data processing was performed on neuromapper ("Neuroscience", Great Britain). Principal attention was paid to the dynamics of spatial-temporal relations of the alpha rhythm. Cyclic changes were shown of the alpha-rhythm amplitude, proceeding with change of high and low amplitudes during seconds, varying in time in various individuals. Three types of spatial distribution of the alpha rhythm over the cortex at the relative rest were obtained: 1) generalized distribution over the cortex with the wavy shift of the frequency fields; 2) formation of delimited local zones of the alpha rhythm, differing by the frequency from the rhythm in other cortical areas; 3) local zone of the low-frequency alpha rhythm in the visual projection zone (18 and 19 fields). Change of the distribution types of the alpha rhythm in the state of rest takes place in the seconds of time intervals, corresponding, according to the literature data, to the proceeding of elementary mental processes.

Adult↗
PubMedDate not supplied

[The locked-in patient and the characteristics of the electrical activity of his brain].

"Locked-in" state differs from the known states characterized by the motor activity blockade, preservation of conscience of speech contact, despite the fact that connection with outer world during this state is limited only by vertical movements of eyes and eyelids in response to speech signals. Three "locked-in" men were studied at different stages of development of this state. Spectral-coherent analysis of the EEG was conducted. The most typical for the developed state of the "locked-in" man is a uniform change of the intercentral EEG relations. In the motor areas of the cortex alpha-activity and its links are not formed (coherence in alpha-range is zero) while high and low frequencies are coherent. In the visual areas, in contrast, the alpha-rhythm is coherent. Distinct interhemispheric asymmetry of coherent connections appears. In the right hemisphere a decrease of coherence level is sharp and even, in the left one--in occipito-temporal parts the level remains close to norm, while in the frontal parts of the cortex it decreases.

Alpha Rhythm↗
PubMedDate not supplied

[Optimal structure of the connections of the electrical processes in the human cerebral cortex and its disorders in changes of state].

In this paper the data are analyzed on the human EEG investigation. Significance is shown of parameters of correlative and spectral-coherent EEG functions for the estimation of the brain functional state of healthy people and patients with local cerebral lesions. In the norm, the parameter of the mean coherence is stable, its characteristics correspond to the optimum cortical tone, the most favourable for the performance of the cortical functions. In healthy people unstable, individual, different in different cortical areas changes of the spectrum details, coherence and phases reflect local processes, taking place at the optimum mean level of the coherence and form the cortical mosaic. These two sides of the intercentral relations of the electrical processes (optimum level of coherence and dynamic mosaic of connections of separate rhythms) reflect the most favourable conditions of the nervous processes development. In the brain pathology, different forms are noted of deviations from the system of intercentral relations and levels of coherence of cortical electrical processes.

Brain Diseases↗