[Electroencephalograpic Parameters of Healthy Persons with Different Successfulness of Dual-Task Performance (Postural Control and Calculation)].

Complex electroencephalographic (EEG), stabilographic and psychological study was executed during the number dual tasks performance--postural control and calculation in 25 healthy volunteers (age 25 ± 0.7). Successful performances of dual tasks required a high usage of cognitive resources, such as memory and attention as well as good motor command and low level of anxiety. Two EEG-markers of successful dual tasks performance were revealed. An increase of EEG coherence for long diagonal pairs of leads between frontal and parieto-occipital areas was observed. Additionally a decrease of EEG coherence for short pairs of leads was revealed. The poor performance of dual tasks was accompanied by an increase of EEG coherence between local pairs of leads for different spectral bands.

[The classification of functional disorders of brain activity in patients with brain tumors].

This paper is devoted to the automatic classification of functional disorders of brain activity in patients with brain tumors on the basis of the reference groups. The test of statistical hypotheses set made crisp classification. Functional activity of the brain abnormality is assessed indicators of the frequency spectrum of the EEG. We describe the scheme of the algorithm and an analysis of the results. The publication is intended for IT-professionals and clinicians who are actively applying them in their work.

[Comparison of reactive EEG changes and fMRI characteristics of brain health based on multivariate statistics].

To gain a deeper insight into the relationship between the electrogenesis and oxygenation of the brain, fMRI and EEG reactions to identical functional loads (opening of the eyes and right- and left-hand fingering) were compared in 11 young right-handed healthy subjects with statistical techniques. Changes in power, frequency and coherent EEG parameters obtained by 18-channel monopolar recording were compared with values of + BOLD-fMRI response, calculated for 18 corresponding cortical areas on the basis of application of the "virtual cap" by the original algorithm. In reactive changes of both hemodynamic and bioelectrical parameters, sets of independent factors were identified, which were regarded on the basis of their topography as specific (localized in the cortical representation ofa relevant analyzer) and nonspecific (diffuse and similar under different functional loads). Specific component dominated in the fMRI response, whereas non-specific component was characteristic of the EEG reaction. The similar topography of reactive fMRI and EEG factors under normal conditions, confirmed by the correlation analysis, reflects the multilevel character of the systemic organization of the brain activity, visualized, in particular, in the sagittal projections of the individual fMRI images. Each of the reactive EEG factors included all of the EEG quantitative characteristics. EEG coherence, which dominated among other parameters (with a local increase in the cortical representation of a relevant analyzer and a diffuse decrease in the areas of the influence of the regulatory structures) displayed the highest correlation with hemodynamic responses of the brain.

[Identification of highly specific electroencephalographic patterns in patients with neuroepithelial tumors of the III ventricle by algorithmic methods].

An algorithm was suggested for identifying highly specific electroencephalographic (EEG) patterns in neurooncologic patients. The algorithm provides selection of patients with their further classification into main and control groups based on the already existing database of EEG indicators; requests to it; generation of mono-indicator candidates for EEG-patterns on the basis of a 4-dipole table for selecting and verifying sensitive and specific EEG patterns and outlining the best ones. Our material included 368 patients with basal-diencephalic tumors. Algorithmic methods revealed new EEG patterns in patients with different anatomical and topographical variants of neuroepithelial tumors in the III ventricle. We think it reasonable to use the revealed syndromes to improve diagnosis and identify pathophysiological basis of clinical syndromes.

[Algorithm identification of differential diagnostic clinical syndromes in patients with neuroepithelial tumors of the III ventricle].

An algorithm for identifying differential diagnostic clinical syndromes in neurooncologic patients was suggested. This technique involves: creating a database of cases - lists of symptoms, requests for selection of thematic cases with their subsequent division into the main and control groups; generation of single-symptom applicants; selection and verification of clinical differential diagnostic syndromes appropriate to sensitivity and specificity using a 4-dipole table and selection of the best of them. Based on the database of 368 patients with tumors of basal-diencephalic localization, we tried to perform the algorithm of identification of differential diagnostic clinical syndromes in patients with different anatomical and topographical variations of neuroepithelial tumors of the III ventricle. The identified syndromes are reasonable to use for selecting the optimal treatment strategy.

[Mathematical analysis of EEG in consciousness recovery after traumatic brain injuries].

The clinical and EEG study of 20 patients with post-comatose consciousness disturbances caused by severe traumatic brain injuries (9 patients with autonomic state and 11 with Korsakoff syndrome), applying a statistical method of analysis of EEG spectrum and coherent connections developed by the authors, has revealed pathological features of the EEG interhemispheric connections. Patients with consciousness disturbances exhibited (1) total functional disconnections of hemispheres which was characteristic of the autonomic state and (2) disconnection in frontal areas of the brain in patients with Korsakoff syndrome as compared to the normal spatial distribution of coherence observed in 40 healthy people. Consciousness recovery has been accompanied by interhemispheric connections normalization, at first in the posterior regions of the hemispheres and then in the anterior ones as well as by transforming of coherence profile in the shape of "envelope" being most typical for the normal pattern of coherence distributation.

Characteristics of brain bioelectrical activity in post-traumatic Korsakov's syndrome.

A total of 32 patients (21 with reversible and 11 with chronic Korsakov's syndrome of traumatic origin) and 20 healthy controls were studied. Visual and spectral coherence analysis was applied to EEG recordings and the three-dimensional localization of equivalent dipole sources of beta1 activity in the frequency range 13-20 Hz. Stable increases in the coherence of EEG beta1 activity generated by a limited number of sources (mostly frontobasal and brainstem locations) had negative prognostic significance in Korsakov's syndrome. Comparison with clinical data allow this EEG phenomenon to be linked to the inhibitory state of the corresponding cortical zones.

[Particular aspects of bioelectric brain activity in post-traumatic Korsakoff syndrome]. / Osobennosti bioélektricheskoi aktivnosti mozga pri posttavmaticheskom korsakovskom sindrome.

Thirty two patients, 21 with recurrent and 11 with chronic Korsakoff's syndrome of traumatic genesis, and 20 healthy subjects were studied, using visual and spectral coherent EEG analysis and investigation of three-dimensional localization of dipolar beta 1-activity sources (13-20 Hz EEG bands). In Korsakoff's syndrome, negative prognostic significance of a stable increase of EEG beta 1-activity coherence generated by a limited number of sources, preferably of frontal basal and stem localization, was found. In the context of clinical data, this EEG phenomenon may be related to inhibited state of corresponding cortical areas.

[Cerebral low T3 syndrome]. / Mozgovoi sindrom nizkogo T3.

The authors studied the time course of changes in the parameters of the cerebral thyronergic system (total and free triiodthyronine (T3) and thyroxin (T4), thyroxine-binding globulin (TBG), thyroid-stimulating hormone (TSH) by radioimmunoassay (Immunotech, Czechia; CIS, France), proinflammatory cytokine of TNF-alpha by enzyme immunoassay (Innogenetic, Belgium) in the blood and cerebrospinal fluid (CSF) in 59 patients (37 males and 22 females whose age ranged from 21 to 64 years) in acute subarachnoidal hemorrhage due to arterial aneurysmal rupture. On admission, the condition of 47 (79.7%) was rated as grades III-VI according to the Hunt-Hess scale, which was responsible for high mortality rates (33.89% in the assessment of outcomes according to the Glasgow outcome scale). The causes of death were ischemic and hemorrhagic insults, edema of the brain, cerebral stem wedging. Laboratory findings were analyzed in relation to the clinical condition of patients, outcomes, and the degree of secondary vasospasm assessed by Doppler transcranial study by the average blood flow velocity in the middle cerebral artery. They revealed a significant depression of thyroidal metabolism with developed the total low T3 syndrome just before surgical treatment in patients with deterioration in the early postoperative period. The significant correlations found by the authors between the decreased blood T3 and TSH levels and 1) the severity of neurological disorders; 2) the degree of vasospasm, and 3) the outcome of disease, as well as negative correlations of elevated TNF-alpha levels not only in the blood, but also in CSF with the content of CT3, CT4 and with the severity of neurological symptomatology are indicative of the development of isolated syndrome in the brain, which is characterized by specific thyroidal metabolic disorders, which the author propose to call the cerebral low T3 syndrome (by taking into account the presence of the autonomic systems of thyroidal homeostatic provision).

[Involvement of thyroid hormones in mental recovery following severe craniocerebral trauma]. / Rol' tireoidnykh gormonov v protsesse vosstanovleniia psikhicheskoi deiatel'nosti posle tiazheloi cherepno-mozgovoi travmy.

To study a role of thyroid hormones in the recovery of mental performance, 71 patients (60 males, 11 females) aged 7 to 66 years (mean age 32.7 +/- 3.5) with severe brain injury (TBI). According to the stage of mental recovery (1--none; 2--elementary acts; 3--verbal contact; 4--spatial orientation; 5--intellectual and mnestic processes and emotional and personality traits), the study was divided into 5 series. Immunoradiometric assay of thyroid hormones (T3 and T4) and their free fractions (FT3 and FT4), thyroid-stimulating hormone (TSH), thyroxine-binding globulin (TBG), and prolactin (P) revealed significant alterations in thyroid metabolism at stages 1 to 4, which appeared as low T3 syndrome. The thyrotropin-releasing hormone (TRH) test made in study series 3 to 5 suggests that the patients have neuroendocrine dysfunctions at the mentioned recovery stages of mental functions of the brain. There was a close relationship of clinical parameters (mental time course) to alterations in the thyroid status and metabolism and to morphological impairments of brain tissues in their traumatic damage, which is evidenced by a correlation of the levels of blood and spinal fluid markers (neurone-specific enolase--NSE and protein S-100) of brain injury with psychopathological disorders (r = -0.96 and -0.6, respectively; p < 0.05) and by the assessment of TBI outcomes (r = -0.65 and -0.62, respectively; p < 0.05). Thus, the findings clinically confirm the neurotransmitter role of thyroid hormones at the stages of mental recovery. In addition, the results show that measurement of blood T3, FT3, TSH, T4, TBH, and NSE should be included into neurochemical monitoring in SBI as prognostically significant criteria. They also may serve as a basis for timely correction of thyroid metabolism.

[Intercentral EEG relationships in regressive and chronic post-traumatic Korsakoff syndrome]. / Mezhtsentral'nye otnosheniia EEG pri regressiruiushchem i khronicheskom posttravmaticheskom Korsakovskom sindrome.

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.

Thyroid hormones in comatose patients with traumatic brain injury.

The objective was to study if thyroid hormones, cortisol, prolactin and brain injury marker levels were changed in traumatic brain injury (TBI) patients with changing levels of consciousness. We estimated the above named parameters in 32 patients (27 men and 5 women aged 11-55). Admission Glasgow Coma Score was < 8. Follow-up period--30 days. The length of coma was 3 to 25 days. There were significant decreases in TSH, TBG, FT3 and F_levels (p < 0.05, for each) and a T3 increase (as compared to very low preceding values) on day 1 before emergence from coma and considerable post-coma increase in TBG, FT3, TSH and F levels (p < 0.001 each) on days 1-3 in patients with diffuse axonal injury (DAI). In patients with contusions and epidural and subdural hematomas (CH) T3 and T4 levels continued to fall until 4-6 postcoma days. TSH values significantly increased up to average normal ranges (p < 0.05) on days "-" 2 and "-" 1 before emergence from coma and remained so. Significantly lower levels of TSH, F and PRL were found in patients with CH in the mostly remote period (on days "-" 12-"-" 8) before emergence from coma in comparison with DAI patients. In blood the following correlations of examined parameters were established: between NSE and T3 (r = -0.39), NSE and FT3 (r = -0.59), TNF alpha and TBG (r = -0.64), TNF alpha and T3 (r = -0.3) and S-100 and T3 (r = -0.3) (p < 0.05, for each). The results obtained confirmed a low T3 syndrome in comatose TBI patients. We demonstrated an objective and informative interdependence: the turning-point moment of the emergence from coma was accompanied by significant changes of examined hormone levels and brain injury marker levels. The results may serve as a base for recommending monitoring FT3 and T3 levels simultaneously with that of other injury markers and adequate T3 replacement therapy in the early posttraumatic period.

[Chemiluminescent study of free radical lipid peroxidation in the rabbit brain after cranio-cerebral trauma]. / Khemiliuminestsentnyi metod issledovaniia svobonoradikal'nogo okisleniia lipidov v mozge krolikov pri cherepno-mozgovoi travme.

The method of chemiluminescence was applied for the determination of free radicals content in rabbit brain after the experimental craniocerebral trauma. The level of malondialdehyde was measured spectrophotometrically. The quantity of free radical products in hemispheres, brain stem and cerebellum of rabbits with traumatic injury was shown to be significantly increased and correlated with MDA level. Data obtained indicate that the chemiluminescent technique can be useful for the investigation of lipid peroxidation in brain pathology.

[The electroencephalographic correlates of a disorder in higher cortical functions in local lesions of the hypothalamic area]. / Elektroéntsefalograficheskie korreliaty narusheniia vysshikh korkovykh funktsii pri lokal'nykh porazheniiakh gipotalamicheskoi oblasti.

In order to reveal correlations between disturbances in higher cortical functions and characteristics of electrical activity 70 patients with pathological foci in the hypothalamic regions were examined using computer data processing. Destruction of the normal intercentral relations between EEG rhythms develops under the influence of the hypothalamic focus. The process builds up with the aggravation of cortical disorders (mnestic, emotional-affective, consciousness oppression with sleep inversion). General decrease of EEG coherence is observed with the highest destruction of correlations in the frontal cortical areas. The structure of high-frequency alpha-rhythm becomes deranged even in slight cortical disorders, its coherence decreases predominantly in the frontal cortical areas. With intensification of the pathological process in the focus, the stage of delta-rhythm coherence increase is observed and at the background of general destruction of correlations new, pathological intercentral relations develop. Using a BRAINLOC computer technique "sources" of the delta- and theta-activity have been localized in the medio-basal brain regions. The area of localization is specific for hypothalamic lesions. The "source" is mostly expressed in the slightest pathology of higher cortical functions. With aggravation of the process in the hypothalamic pathological focus and further derangement in the cortical functions expression of the "sources" reduces up to their complete disintegration in coma.

[Automated roentgenography of the thoracic organs]. / Avtomatizirovannaia rentgenografiia organov grudnoi kletki.

A new device is developed to trigger automatically an X-ray unit at the instant of the extremum respiratory phase. The device is driven by a probe sensing the air stream. The serviceability of the unit has been tested in the course of pneumopolyradiographic and pneumotetraradiographic examinations in more than 5000 patients. The unit is recommended for clinical application in the X-ray departments.

[Thermography in the diagnosis of spontaneous lumbosacral radiculitis]. / Termografiia v diagnostike spontannykh poiasnichno-krestsovykh radikulitov.

Employing the Soviet thermal scanner "Rubin", 59 patients aged 20 to 65 years suffering from lumbosacral radiculitis were examined. Clinical examinations were supplemented with spondylography , epidurography, pneumomyelography and myelography. Operation performed on 29 patients showed a slipped disk in 26 and hypertrophy of the yellow ligament in three patients. The level and the side of compression of one or another neural root by the slipped disk detected at operation correlated with the thermographic data in 72% of all cases. An analysis of the thermograms in 59 patients with lumbosacral radiculitis demonstrated that thermographically the given disease was manifested by the zone of hyperthermia in the lumbosacral area and the disruption of the thermal flow in the form of hypothermia in the lower extremities which in 72% of cases was distributed according to the stripe type. The side and the level of compression of the neural root are also outlined.