[Arm Motor Function Recovery during Rehabilitation with the Use of Hand Exoskeleton Controlled by Brain-Computer Interface: a Patient with Severe Brain Damage].

We studied the dynamics of motor function recovery in a patient with severe brain damage in the course of neurorehabilitation using hand exoskeleton controlled by brain-computer interface. For estimating the motor function of paretic arm, we used the biomechanical analysis of movements registered during the course of rehabilitation. After 15 weekly sessions of hand exoskeleton control, the following results were obtained: a) the velocity profile of goal-directed movements of paretic hand became bell-shaped, b) the patient began to extend and abduct the hand which was flexed and adducted in the beginning of rehabilitation, and c) the patient began to supinate the forearm which was pronated in the beginning of rehabilitation. The first result is an evidence of the general improvement of the quality of motor control, while the second and third results prove that the spasticity of paretic arm has decreased.

[Influence of the brain functional state evoked by spreading depression wave propagation on the recurrent waves properties].

EEG aftereffects of spreading depression waves were studied in waking rabbits in chronic experiments by spectral coherence analysis. Experiments were divided in two groups: early (from the first to the third-fourth experiments) and late (fifth-tenth experiments). During the early experimental series, unilateral persistent EEG changes consisting in an increase in the delta- and beta-band power with a simultaneous depression of the gamma-band activity were observed in the ipsilateral to SD hemisphere. In addition, interhemispheric coherence between symmetrical cortical points decreased. During the late experimental series, a generalized bilateral increase in the power of the delta and beta activity was demonstrated with a rise in coherence in the beta band. This generalized activity occurred cyclically and was distinct during a long period of time (2-3 hours) after propagation of a single SD wave. Such kind of cyclical activity blocked the propagation of subsequent SD waves in the neocortex of a waking rabbit and decreased the probability of recurrent wave origin up to a complete cessation of wave generation. Thus, a cortical SD wave provoked the appearance of synchronized beta oscillations in the EEG, which in turn actively influenced the properties of recurrent waves.

[Influence of music on a decision of mathematical logic tasks].

Accompaniment of a decision of mathematical logical tasks by music (different style and power) influenced on the time of the decision. Classical music 35 and 65 dB and roc-music 65 and 85 dB decreased the time of the decision. More powerful classical music (85 dB) did not effect like that. The decision without the musical accompaniment led to increasing of coherent values especially in beta1, beta2, gamma frequency ranges in EEG of occipital cortex. The intrahemispheric and the interhemispheric coherences of frontal EEG increased and EEG asymmetry (in a number of Coh-connections in left and right hemispheres) arose during the tasks decision accompanied by music. Application of classical music 35 and 65 dB caused left-side asymmetry in EEG. Using of more powerful classical or rock music led to prevalence of quantity of Coh-connections in a right hemisphere.

[Decision of mathematical logical tasks in sensory enriched environment (classical music)].

The time of a decision of mathematical logical tasks (MLT) was decreased during classical musical accompaniment (power 35 and 65 dB). Music 85 dB did not influence on the process of decision of MLT. Decision without the musical accompaniment led to increasing of coherent function values in beta1, beta2, gamma frequency ranges in EEG of occipital areas with prevalence in a left hemisphere. A coherence of potentials was decreased in EEG of frontal cortex. Music decreasing of making-decision time enhanced left-sided EEG asymmetry The intrahemispheric and the interhemispheric coherences of frontal cortex were increased during the decision of MLT accompanied by music. Using of musical accompaniment 85 dB produced a right-side asymmetry in EEG and formed a focus of coherent connections in EEG of temporal area of a right hemisphere.

[Effect of music on the latency recognition of even and odd numbers].

Studied influence of music of certain intensity on latency recognition of even and odd numbers with participation of the left and right hand accordingly. Music accompaniment decreased the latency recognition more pronounced with participation of the left hand that, apparently, is connected with activated influence of music on the right hemisphere at the people who are not professional musicians. Increase of efficiency of recognition in music accompaniment is considered as realisation of a principle of a dominant.

[Changes in the high-frequency electrical brain activity in the animal hypnosis state in rabbits].

The EEG spectral analysis applied to electrical brain activity of rabbits in the state of animal hypnosis revealed a 2-4-fold increase in the power of the sigma frequency band (12-17 Hz) and a 1.5-2-fold decrease in the gamma frequency (especially 40-70 Hz) in addition to well-known growth of delta (0.3-3 Hz) and reduction of theta activity (4-8 Hz). The changes were more prominent in the frontal cortex areas. The influence of hypnotic state on cortical gamma activity pharmacologically augmented by ketamine injection was analyzed. Administration of subanesthetic ketamine doses led to behavioral locomotor excitation of an animal accompanied by a long-lasting (up to 2 h) increase in the gamma electrical activity. If the animal hypnosis was induced after the ketamine injection, it resulted in an almost instant reorganization of the spectral power. The slow-wave power increased and the gamma-power decreased to the baseline levels. Thus, the animal hypnosis eliminated the reorganization of cortical rhythmicity produced by ketamine, which suggests a stabilizing and, to a certain extent, protective function of this kind of hypnosis in the states of behavioral locomotion and stress.

Influence of music with different volumes and styles on recognition activity in humans.

The efficiency of the recognition of masked visual images (Arabic numerals) increased when accompanied by classical (62 dB) and rock music (25 dB). These changes were accompanied by increases in the coherence of potentials in the frontal areas seen on recognition without music. Changes in intercenter EEG relationships correlated with the formation a dominant at the behavioral level. When loud music (85 dB) and music of other styles was used, these changes in behavior and the EEG were not seen; however, the coherence of potentials in the temporal and motor cortex of the right hemisphere increased and the latent periods of motor reactions of the hands decreased. These results provide evidence that the "recognition" dominant is formed when there are particular ratios of the levels of excitation in the corresponding centers, which should be considered when there is a need to increase the efficiency of recognition activity in humans.

Dynamics of changes in electrical activity in the rabbit cerebral cortex during sequential sessions of "animal hypnosis".

The dynamics of changes in individual electrical activity rhythms in the premotor, sensorimotor, and temporal-parietal areas of the cortex in both hemispheres were studied in chronic experiments in rabbits during sequential sessions of "animal hypnosis." These experiments showed that during the first session of "animal hypnosis," significant changes in electrical activity occurred only in the premotor area of the cortex of the right hemisphere, where there were increases in spectral power in the delta-1 and delta-2 ranges and decreases in spectral power in other ranges of electrical activity. Subsequent sessions of "animal hypnosis" formed increasing changes in electrical activity, which were particularly marked in cortical areas in the right hemisphere. Significant changes in spectral power in the delta and theta ranges of electrical activity in cortical areas did not arise at the beginning of the hypnotic state, but after 4-6 min. During the third session of "animal hypnosis," the course of electrical activity in the alpha and beta rhythms in the premotor and sensorimotor areas of the cortex became wave-like in nature.

[EEG in mathematical logical problem solving].

The model of mathematical logic tasks was developed at which decision there was a value coherence in delta-range raised. In low-frequency ranges (delta, theta, and alpha) a coherence of potentials of frontal cortex were increased. In high-frequency ranges (beta1, beta2, gamma) in frontal cortex coherence was decreased, and its increasing in central, parietal, temporal, and occipital areas with prevalence in the left hemisphere. Most changes of quantity of positive connections observed in value diagonal coherence. Analysis of spectral power EEG has shown, that at the decision of tasks there is a generalised raising on a cortex in delta-range. Theta-activity increased in a frontal cortex, and gamma band was raised in occipital areas. A spectral power in an alpha range mainly decreased.

[Influence of music different in volume and style on human recognition activity].

The efficiency of recognition of masked visual images (Arabic numerals) under conditions of listening to classical (intensity 62 dB) or rock music (25 dB) increased. Coherence of potential in the frontal cortical region characteristic of the masked image recognition increased under conditions of listening to music. The changes in intercenter EEG relations were correlated with the formation of "the recognition dominant" at the behavioral level. Such behavioral and EEG changes were not observed during listening to louder music (85 dB) and listening to music of other styles, however, the coherence between potentials of the temporal and motor areas of the right hemisphere increased, and the latency of hand motor reactions decreased. The results suggest that the "recognition dominant" is formed under conditions of establishment of certain relations between the levels of excitation in the corresponding centers. These findings should be taken into consideration in case if it were necessary to increase the efficiency of the recognition.

[The dynamics of modification of electrical activity of the rabbit brain during consistent "animal hypnosis" series].

The dynamics of modification of individual rhythms of electrical activity in both hemispheres was studied under condition of chronic experiments in rabbits during "animal hypnosis" sessions. It was shown that, after the first "animal hypnosis" session, significant changes in the spectral power of electrical activity appeared only in the right premotor cortical area. They consisted in an increase in the spectral power of the delta1 and delta2 rhythms and a decrease in the spectral power of the other rhythms. During the next "animal hypnosis" sessions, changes in the electrical activity became stronger, especially in the right hemisphere. Significant changes in the spectral power of the delta and theta rhythms appeared not at the beginning of the "animal hypnosis" session but 4-6 min later. During the third "animal hypnosis" session, the power of the alpha and beta rhythms in the premotor and sensorimotor cortical areas of both hemispheres varied in an undulatory way.

Properties of spreading depression identified by EEG spectral analysis in conscious rabbits.

Reflection of cortical waves of spreading depression in changes in high-frequency gamma activity was shown to improve significantly in conditions of bipolar recording of brain electrical activity. Intense suppression of the EEG gamma range (37-47 Hz) was seen in all cortical areas studied at the moment of onset of waves of spreading depression. The drop in the power of EEG gamma activity had clear leading and trailing fronts, allowing the passage time of the wave to be evaluated in each cortical area, as well as the sequence of propagation. Waves of spreading depression were characterized by normal, i.e., sequential movements across the cortex, only in the first 3-4 experiments. When experiments were continued, there were changes in the latent period and distortions of the propagation sequence. In some cases, waves of spreading depression responded to standard injections of KCl by developing rapidly (0.5-2 min) over the whole of the dorsal surface of the neocortex. More frequently, the wave was delayed (to 6-9 min) was completely blocked in some areas of the cortex. Different types of mild convulsive activity could accompany both the rapid propagation of waves across the cortex and inhibition of wave development. In most cases, there were no electrophysiological signs of changes in neocortical excitability. However, alterations to the spatial characteristics of waves of spreading depression and the spontaneous appearance of repeated waves provided evidence of changes in the functional state of the brain. Overall, EEG spectral analysis in conscious rabbits allowed analysis of spreading depression both in cases of sequential propagation across the cortex and in cases of atypical modes of development of this phenomenon.

[The treatment of an acute paraproctitis].

The results of surgical treatment of an acute paraproctitis in 708 patients, in 9 (1.27%) of whom gangrenous -- putrificated form of paraproctitis was diagnosed, are adduced. In 187 (42.6%) patients the abscess disclosure with intraintestinal purulent fistula, going into intestinal lumen, excision was performed, together with cryptectomy -- in 182 (41.4%), the ligature method was applied in 18 (4.1%) with subsequent fistula excision and its internal orifice plasty using mucosal-submucosal flap. For extrasphincteric or transsphincteric purulent tunnel the abscess was opened and drained, its internal orifice sutured, using 'distant" removable suture. It internal orifice was not revealed there was accomplished procedure of disclosure and draining of purulent cavity, the wound sanation with insufflation of ozone-oxygen mixture. In anaerobic paraproctitis the procedure consisted of disclosure and draining of purulent cavities with necrectomy was performed. To all the patients antibacterial therapy was conducted. In 20 (4.5%) patients an acute paraproctitis recurrence had occurred, in 9 (2%) -- pararectal fistula, and in 5 (1.1%) -- the anal sphincter stage I insufficiency.

[Spreading depression in a waking rabbit with the spectral EEG analysis].

It was shown that the manifestation of the SD phenomenon in dynamics of the cortical high-frequency gamma activity is rather prominent after bipolar interpretation of the common reference electrode derivations, i.e. when the modeling of the bipolar signal on the base of monopolar EEG recordings is used. The SD wave was accompanied by significant decrease in the power of the EEG gamma band (37-47 Hz) in all observed cortical areas. A curve of decline of gamma activity power had distinct fore and back fronts, so the time of SD appearance in different cortex areas and it's spread succession could be well determined. In the long-term experiments SD waves were characterized by normal (i.e. successive) spread through the cortex mainly in initial three-four experiments. In the subsequent tests latency of SD waves in different cortex areas changed and disturbance of propagation became obvious. Sometimes SD arose rapidly (due 0.5-2 min) on the whole dorsal neocortical surface, when the standard injection of the KCI was done. In the most of experiments the delay of the SD wave appearance was prolonged till 6-9 min or no SD wave occur at some cortical regions. Week epileptiform activity could conduct abnormalities in the SD. In many instances electrophysiological signs of the cortical excitability changes were absent. However the modified spatial SD characteristic and spontaneous occurrence of the repeated. SD waves indicated the increased functional inhomogeneities of the neighboring cortical areas. So, spectral EEG analysis in awake rabbits made it possible to characterize the SD wave both in case of its normal propagation through the cortex and in unusual forms of this reaction.

Suppression of EEG gamma activity--an informative measure of spreading depression waves in the neocortex of the conscious rabbit.

Spreading depression can arise spontaneously in convulsions, migraine attacks, vascular lesions, and other pathological brain states. However, the methodological complexity of recording a direct current potential in the neocortex in humans and conscious animals significantly limits studies of the functional consequences of spreading depression. The present report describes a detailed analysis of the EEG dynamics at the moment of development of spreading depression waves and identifies specific signs allowing spreading depression to be recorded without recording changes in the direct current potential. At the moment of arrival of spreading depression, the interhemisphere equilibrium is highly disturbed because of large decreases in high-frequency activity. The time parameters of the dynamics of the gamma-1 and gamma-2 ranges were the most informative features of the development of spreading depression waves. Increases in power in the delta range developed with some delay on the background of a deep inhibition of high-frequency activity and are in essence a consequence of spreading depression. The encephalographic criteria of spreading depression waves identified here can significantly simplify the detection of this phenomenon both in experimental and clinical conditions in a number of pathological brain states.

[Suppression of gamma EEG activity as an index of a spreading depression wave in the neocortex of a waking rabbit].

A spreading depression (SD) can spontaneously develop in seizures, attacks of migraine, vascular disorders and other pathological states of the brain. However, problems in technique of recording the DC-potential in the neocortex of humans and waking animals substantially restrict the possibilities of studying functional consequences of the SD. In this article, the EEG pattern was studied in detail at the moment of the SD development. Specific features were revealed, which make it possible to detect the SD without recording shifts of the DC-potential. At the moment of the SD arrival, the interhemispheric balance drastically disturbs because of a strong decrease in the high-frequency activity. By the time indices, the course of the suppression of the gammal and gamma2 EEG frequencies is the most reliable symptom of the SD wave development. The EEG spectral power in the delta band increases with a certain delay in reference to the deep depression of the high-frequency activity and is, in essence, an SD aftereffect. The found EEG signs of an SD wave can substantially simplify the identification of this phenomenon both in experiment and clinical conditions in certain pathological states of the brain.