[Changes in the Functional Connectivity of Motor Zones in the Use of Multimodal Exoskeleton Complex "Regent" in the Neurorehabilitation of Post-Stroke Patients].

The article discusses the effect of a course of treatment with the use of multimodal complex exoskeleton (MCE) "Regent" on the reorganization of cortical locomotor zones in 14 patients with post-stroke hemiparesis, mainly atthe chronic stage of the disease. Before the course of treatment, we identified specific areas of activation in the primary sensorimotor and supplementary motor areas and the inferior parietal lobules in both affected and healthy hemispheres by means of functional MRI (fMRI) with the use of special passive sensorimotor paradigms. After the course of treatment with MCE, we observed an improvement of temporal characteristics of walking; it was accompanied by a decrease in the activation zones of inferior parietal lobules, especially in the healthy hemisphere, and by a significant increase in the activation zone of primary sensorimotor and supplementary motor areas. The analysis of the functional connectivity of studied zones before and after the course of treatment with MCE showed significant changes in intra- and interhemispheric interactions.

[New approaches in the study of neuroplasticity process in patients with central nervous system lesion].

Methods which on one hand can ensure the patient's mobility and on other hand activate afferents inputs are the main in rehabilitation treatment. Recent studies has shown that plasticity is structural base of recovery after central nervous system injury. Reorganization of cortical areas and increase of preserved structures functional effectiveness (intensification afferent input) are an anatomical basis of plasticity. However, sensory correction methods, without accounting of functional condition of patients, can lead to the formation of pathological symptoms: spasticity, hyperreflexia, etc. So the main aim is to study adequate management of the neuroplasticity process. This problem cannot be solving without modern methods of neuroimaging and brain mapping. The new approach for study cortical mechanisms of neuroplasticity, responsible for locomotion, was developed in the present study. This approach is complex use of functional magnetic resonance imaging (fMRI) and navigation transcranial magnetic stimulation (nTMS). It was showed that vast fMRI activation area in the first and the second sensorimotor area emerges with passive sensorimotor paradigm using that imitate backing load during walking. The mechanical stimulator footsteps backing zones "Corvit" uses for create this paradigm, nTMS examination, which used after fMRI, help localize the motor representation of muscles which control locomotion more accurately. We guess that new approach can be used for neuroplasticity process study and assessment of neuroplasticity changes during rehabilitation for restore and correct the walking.

[Specifics of activation of cortex by stimulation of support receptors in healthy subjects and in patients with lesions of CNS].

Results of basic studies in space medicine revealed the mechanism of motor disorders and the importance of support input in regulation of the tone and posture system of the mammals. Progress in functional magnetic resonance tomography (fMRT) enabled in vivo estimation of activity of various parts of the brain during stimulation of support afferent pathways. The goal of our study was to detect specific activation of the cortex during stimulation of support input in healthy subjects and in patients with lesions of CNS. The study included 19 healthy volunteers (mean age of 38 ± 15, 13 years) and 23 patients with cortical-subcortical ischemic stroke (mean age 53 ± 9.07); all subjects underwent fMRT. During scanning of each subject, support areas of the foot soles were stimulated to imitate slow walking using the block design. In healthy volunteers, primary somatosensory cortex, premotor and dorsolateral cortex, and insula were significantly activated (corrected <0.05 at cluster level). In patients with stroke, pattern of activation of the supraspinal systems of locomotion control clearly depended on the stage of the disease. In patients with cortical-subcortical stroke undergoing motility rehabilitation, the sensomotor locomotion module was predominantly activated as the contralateral pattern.

[Activation of the sensorimotor cortex with the use of a device for the mechanical stimulation of the plantar support zones].

Studies of the control movements mechanisms have been performed in the interest of space medicine were the basis for the development of the concept about the leading role of the support afferent input in the regulation of postural-tonic system of mammals. Introduction of functional magnetic resonance imaging (fMRI) made it possible to investigate in-vivo brain mapping during stimulation of support afferent input. The aim of our study was to investigate brain activation due to mechanical support stimulation of the soles with the special device "Korvit". 12 healthy participants (6 women, 6 men; average age = 28.8 years) were scanned. fMRI protocol for each person consisted of 2 different blocked paradigms: soles stimulation in stance imitation (1) and slow walking imitation (2) modes. The results were analyzed with statistical program SPM5 for each person and then for the whole group. In all our paradigms there was significant (P(correct) < 0.05 for cluster level) activation of primary somatosensory, premotor and dorsolateral cortex, insula. During the stance imitation mode, extensive prefrontal cortex activation was observed; during the slow walking imitation mode there was activation of different primary and secondary sensorimotor cortex areas.

[Actual issues of the surgery of elderly patients].

The results of 1516 operations, directed on complications prophylaxis and quality of life improvement, performed in 1004 senile patients, were analyzed. The expedience of application of epidural anesthesia in such patients was substantiated.

Effect of mechanical stimulation of the support zones of soles on the muscle stiffness in 7-day dry immersion.

Stiffness of m. soleus (Sol.) and m. tibialis anterior (TA) was evaluated in 16 volunteers during exposure to 7-days dry immersion alone and to the combination of immersion and mechanic stimulation of foot support zones. It was shown that Sol. stiffness decreased progressively starting from day-1 of immersion, whereas TA stiffness, on the contrary, made a sharp rise. Mechanic stimulation of foot support zones slowed down the rate and extent of changes in both muscles.

Muscle transverse stiffness and venous compliance under conditions of simulated supportlessness.

Supportlessness arising as a result of 7 hrs dry immersion is accompanied by decreased transverse stiffness and increased calf venous compliance, as well as impaired orthostatic tolerance. Stimulation of support zones of foot is associated with smoothening of these effects. The latter may be considered as an indirect evidence in favor of the concept of support deafferentation triggering role in development of enumerated unfavorable effects of simulated microgravity.

[Effect of 120 days head-down tilt (HDT) on characteristics of tendinous reflexes]. / Vliianie 120-sutochnoi antiortostaticheskoi gipokinezii na kharakteristiki sukhozhil'nykh refleksov.

Time dynamics of variations in the spinal reflex mechanisms was evaluated during 120-d HDT (-6 degrees). Already within the first days in HDT the knee and Achilles reflexes were noted to sharply become easy to fulfil, the conclusion made from a significant drop of thresholds, an appreciable rise of amplitudes of reflex responses and an expansion of the range of stimulations. However, dynamics of these variations was diverse. The abrupt drop of reflex thresholds determined already on HDT day 2 was persistent throughout the experiment, whereas maximal rise of the tendon reflex amplitude was seen on the initial phase of HDT (days 15-30). Later on, a clear-cut downward trend of the electromyographic amplitude was observed. The experimental data suggest that hyperreflexia during HDT is one of the manifestations of partial deafferentation of the motoneuron pool due to diminution of the proprioceptive afflux. At the same time, hyperactivity of the reflex mechanisms is masked by the peripheral muscular effects of the same factor, i.e. HDT.

[The effect of 120 day anti-orthostatic hypokinesia on the status of the posture regulation systems]. / Vliianie 120-sutochnoi antiortostaticheskoi gipokinezii na sostoianie sistem poznogo regulirovaniia cheloveka.

The system of posture regulation was evaluated during 120-d head-down bedrest (-6 degrees). Functioning of the system was evaluated by the characteristics of corrective posture responses to pushes in the chest breaking the body equilibrium. Analyzed were parameters of amplitude and time of corrective responses, and strength and range of stimulus intensity. Results of the investigation showed that HD bedrest materially disturbs vertical stability and impairs effectiveness of the posture corrective mechanisms. Based on the data of this investigation and findings of previous efforts we can confidently distinguish two phases in development of disturbances in vertical stability during long-term HD bedrest associated with different leading mechanisms. On the first phase (15-30-d into the experiment), the principle posture problems are reduced tone of the anti-gravity musculature. On the second phase, particularly beginning on day 60, muscular atrophy processes become leading factors of postural disturbances. Apparently, these mechanisms, along with changed vestibular input, considerably impact vertical stability, especially after extended space mission.