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Biomedical subjects

N B Kholodova

Publications and source records attributed to N B Kholodova.

At least 19 recordsLinked to original sources
PubMed1996

[The late sequelae of radiation exposure on the nervous system].

Clinical, neuropsychologic, neurophysiologic as well as neuromorphologic (in legal cases) examinations of Chernobyl liquidators were performed. In addition, the study was made of the monkeys exposed to 1,5 Gy radiation. The results obtained testified to the organic character of cerebral damages. They may be characterised as chronic progressive discirculatory-hypoxic syndrome in which disorders of vascular permeability were expressed and dystrophic destructive irreversible alterations of nervous cells occurred.

Adult↗
PubMed1995

EEG power mapping, dipole source and coherence analysis in Chernobyl patients.

EEG power mapping, coherence analysis, source localization of epileptiform activity and psychoneurological investigations were performed in 100 patients (males, 25-45 years old, right-handed), who took part in the cleaning of the Chernobyl disaster in 1986-1987, and compared with a control group (healthy persons of the same age). Neuropsychological studies showed autonomic, endocrine, emotional and other disorders in all patients. About 70% of all patients had paroxysmal EEG activity and intermittent seizures sometimes associated with loss of consciousness. EEG power mapping showed higher than normal levels of alpha- and theta-bands power, mainly in the frontal and central areas in the one group of patients. In others, power was lower especially in alpha-band. Paroxysmal waves of alpha- and theta-bands had localization of dipole sources at deeper near midline levels, and as a rule with a shift to the right hemisphere. Paroxysmal beta-waves demonstrated sources of a diffuse character at a more basal level with a shift to the left hemisphere. Interhemispheric coherences had lower values in the frontal and higher in the central leads than in healthy persons. Intrahemispheric coherences were decreased in the left hemisphere and increased in the right, opposite to that in controls.

Adult↗
PubMed1989

[Dynamics of neurological symptoms during immediate and long-term periods after radiotherapy of patients with brain metastases of malignant tumors].

The paper treats of 60 patients with metastases to the brain, subjected to radiotherapy coupled with hormonal treatment. The control group was made up of 17 patients who did not undergo radiotherapy. It has been concluded that radiotherapy noticeably increases (4-fold) the lifetime of patients with metastases to the brain and that its efficacy depends on timely diagnosis of the latter ones and early terms of the treatment onset.

Adult↗
PubMed1988

[Treatment of patients with facial hemispasm by transcutaneous electric nerve stimulation].

Fifty-two patients (aged 15 to 78 years) suffering from facial hemispasm were treated by transcutaneous electric nerve stimulation (TENS). For this purpose electric-impulse apparatuses generating bipolar nonsymmetrical impulses were employed. The employment of TENS eliminated hyperkinesis for a period of several minutes to several hours. Interparoxysmal intervals lengthened and hyperkinesis became less pronounced. After a TENS session EMG showed no spontaneous activity in the form of "volleys of oscillations". A possible mechanism of TENS therapeutic effect in facial hemispasm is discussed.

Adolescent↗
PubMedDate not supplied

Electroencephalographic correlates of neurological disturbances at remote periods of the effect of ionizing radiation (sequelae of the Chernobyl' NPP accident).

The psychoneurological status of 40 participants (all men aged 25-45 years, official dose 15-51 rem) in the liquidation of the consequences of the accident at the Chernobyl Nuclear Power Plant in 1986-1987 was investigated; EEG mapping and three-dimensional localization of the sources of epileptic activity as compared with the data of healthy individuals (20 individuals) was carried out. Vegetative-vascular symptomatology was identified in the neurological status of all the patients; disseminated organic neurological symptomatology and endocrine disturbances were additionally identified in some of the patients. There were paroxysmal attacks periodically in the overwhelming majority (68%) of the patients; this correlated with the presence in the EEG of epileptic forms of activity. The patients were divided into two groups on the basis of the character of the EEG. Patients in whom slow alpha waves and waves of the theta range with a "focus" in the central-frontal regions of the cortex were recorded were included in group I (25 individuals). Analysis of the localization of the sources of epileptic activity revealed placement at the midline level in them with marked compactness and displacement of the focus to the right hemisphere. In the patients of group II (15 individuals), slow waves of frontal localization and diffuse beta waves predominated in the EEG in the presence of a reduction in the level of biopotentials. The localization of equivalents of epileptic activity was more diffuse in character and was at the basal level, with a greater representation of the sources of epileptic activity in the left hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Postradiation changes in the brain asymmetry and higher mental functions of right- and left-handed subjects (the sequelae of the accident at the Chernobyl Atomic Electric Power Station)].

The present study was aimed at comparative electrophysiological, clinical, and neurophysiological assessment of the brain functional state in dextrals (50 men) and sinistrals (5 men), who participated in the Chernobyl clean. The patients were observed over the course of 10 years (from 1990 to 1999). The results of examination of healthy persons (20 dextrals and 10 sinistrals) were used as a control. The clinical examination revealed the earlier manifestation and more severe development of paroxysmal and epileptic seizures in sinistrals than in dextrals. Electrophysiological study showed a progressive decrease in interhemispheric asymmetry of the EEG coherence characteristic for a healthy brain to inversion of its sign. These changes were more pronounced in sinistrals. In the remote terms after radiation, the interhemispheric EEG coherence decreased over the whole cortex, especially, in the frontal and central areas in both groups of patients. Neurophysiological study revealed a progressive impairment of voluntary motor activity and tactile sensibility, especially, in the left hand. These defects were more expressed in sinistrals than in dextrals. The results of complex and longitudinal examination suggest that the observed changes in brain asymmetry and interhemispheric interaction can be not only a result of a dysfunction of subcortical limbic-reticular and mediobasal brain structures but also a result of the white matter damage including corpus callosum. More expressed impairments in sinistrals than in dextrals can be explained by specific morphofunctional organization of the brain in persons with different sensor and motor asymmetries.

Adult↗
PubMedDate not supplied

[Post-radiation effect on the interhemispheric asymmetry in EEG and thermography characteristics].

Complex analysis of EEG and thermographic parameters carried out in 10 healthy subjects and 34 patients, Chernobyl clean-up participants revealed a correlation between EEG and brain temperature changes in the baseline state and during mental arithmetic. During cognitive activity the maximal increase in the average EEG coherence and temperature shifts in healthy subjects were observed in the left frontotemporal and right parietotemporal areas. In patients changes in both parameters under study were most pronounced, the interhemispheric relations were impaired. The visual analysis revealed "flat" and "hypersynchronous" EEG types in patients. The dominant pathologic activity in the betal range indicative of mediobasal and oral brainstem lesions was characteristic of the flat EEG. This type of activity was observed in 60% of patients. In these cases, a general decrease in EEG coherence and temperature was most pronounced in the left hemisphere. The hypersynchronou EEG type (40% patients) was characterized by paroxysmal activity in the theta and alpha ranges suggesting diencephalic brain lesions. In these cases, EEG coherence and temperature were more variable; changes in the right hemisphere were significant, be it increase or decrease. Our complex approach to investigation of brain activity in different aspects seems to be promising in estimation of the brain functional state both in healthy persons and patients in remote terms after exposure to radiation. The specific hemispheric temperature changes revealed in Chernobyl patients especially during cognitive activity can be the sequels of postradiation disorders of vascular neuro-circulation. The EEG findings suggest subcortical disorders at different levels (diencephalic or brainstem) and functional failure of the right or left hemispheres in remote terms after exposure to radiation.

Brain↗
PubMedDate not supplied

[Impairment of space-frequency parameters of EEG coherence during cognitive performance (consequences of Chernobyl accident)].

Changes in frequency and space parameters of the EEG coherence evoked by cognitive performance were analyzed in 13 healthy subjects and participants of the Chemobyl clean-up. In healthy subjects, the EEG coherences in the alpha and beta frequency bands were significantly increased during arithmetic count and during visuospatial performance. Each test was characterized by regionally-specific features. Chemobyl patients demonstrated a global decrease in the EEG coherence predominantly in the alpha and beta frequency bands, especially in the frontal cortical areas. Patients with various pathological EEG patterns demonstrated specific impairment of EEG parameters. In patients with a "flat" EEG pattern, the EEG coherence predominantly decreased in the frontal associative areas, especially during arithmetic calculation. In patients with a "hypersynchronous" EEG pattern, the decrease in the EEG coherence was most pronounced in the parietal associative areas, especially during the visuospatial performance. The revealed impairments of the EEG coherence reactivity may be a reflection of disorders of the intracortical and corticosubcortical interaction and can result from the remote postradiation brain atrophy, especially, of cortical structures.

Adult↗
PubMedDate not supplied

[Changes in the brain of persons who participated in the cleaning-up of the Chernobyl AES accident based on the data of radiodiagnosis (single-photon emission-computed radionuclide tomography, x-ray computed tomography and magnetic resonance tomography)].

Presents the data of x-ray examinations of the brain in cleaner-ups of the consequences of the Chernobyl power plant accident who complained of headaches, ache in the bones, poor memory, giddiness, weakness, a drastic drop of performance ability, fits with loss of consciousness. Hypometabolic foci localized both in the white and gray matter of the brain were revealed. X-Ray computer-aided tomography and magnetic imaging showed dilatation of the ventricular system of the brain, dilatation of the subarachnoidal spaces, symmetrical reduction of the density of medullary tissue round the bodies and anterior and posterior horns of lateral ventricles, round the third ventricle, near semi-oval centers, as well as solitary or multiple focal reduction of medullary tissue density. Findings of x-ray methods of diagnosis permit a conclusion on a complex organic involvement of the brain in subjects who participated in liquidation of the consequences of the Chernobyl power plant accident. The most typical are signs of the hypertensive hydrocephalic syndrome with cerebrospinal fluid disturbances and of the vascular encephalic syndrome with development of focal postischemic malacia of the brain matter.

Adult↗