— The article discusses the study of neuroplastic changes in the cerebral cortex caused by the use of the soft Regent multimodal exoskeleton complex (MEC) in poststroke patients in comparison with the activation of cortical structures responsible for locomotion in healthy individuals. The MEC course applied to hemiparetic patients increases the walking speed; changes in the activity zones detected by functional magnetic resonance imaging (fMRI) indicate the positive direction of neuroplastic processes: activation in the precentral gyrus (primary motor cortex), the secondary association cortex (inferior parietal lobule) in the affected hemisphere, and in the primary sensorimotor zone on the right. Analysis of functional connectivity of the regions of interest before and after the course of MEC treatment revealed significant changes in inter- and intrahemispheric connections. The positive reorganization of the cortical structures is based on a decrease in the excitatory interactions between the secondary association areas (inferior parietal lobules of the right and left hemispheres) and a lesser inhibitory influence between the inferior parietal lobule and the primary sensorimotor area in the affected hemisphere.

The paper discusses the findings of studying neuroplastic transformations in the brain cortex owing to stroke patients therapy using soft multimodel exoskeleton complex (MEC) REGENT in comparison with activation of the cortex structures controlling locomotion in healthy people. The MEC course applied to hemiparetic patients increases walk speed; changes in the activity zones detected by functional magnetic resonance imaging (fMRI) attest to the positive trajectory of neuroplastic processes, i.e. activation in the precentral gyrus (primary motor cortex), secondary association cortex (inferior parietal lobule) on the damaged hemisphere, and right-side primary sensorimotor cortex. Analysis of the functional connectivity between the areas of interest before and after the MEC therapy elicited significant changes in the inter- and intra-hemispheric connections. This positive cortical reorganization has its origin in reduction of excitory interactions between the secondary associative areas (inferior parietal lobules in both hemispheres) and alleviation of the inhibitory interaction between the inferior parietal lobule and primary right-side sensorimotor cortex in the damaged hemisphere.

The present study reports alterations of task-based functional brain connectivity in a group of 11 cosmonauts after a long-duration spaceflight, compared to a healthy control group not involved in the space program. To elicit the postural and locomotor sensorimotor mechanisms that are usually most significantly impaired when space travelers return to Earth, a plantar stimulation paradigm was used in a block design fMRI study. The motor control system activated by the plantar stimulation involved the pre-central and post-central gyri, SMA, SII/operculum, and, to a lesser degree, the insular cortex and cerebellum. While no post-flight alterations were observed in terms of activation, the network-based statistics approach revealed task-specific functional connectivity modifications within a broader set of regions involving the activation sites along with other parts of the sensorimotor neural network and the visual, proprioceptive, and vestibular systems. The most notable findings included a post-flight increase in the stimulation-specific connectivity of the right posterior supramarginal gyrus with the rest of the brain; a strengthening of connections between the left and right insulae; decreased connectivity of the vestibular nuclei, right inferior parietal cortex (BA40) and cerebellum with areas associated with motor, visual, vestibular, and proprioception functions; and decreased coupling of the cerebellum with the visual cortex and the right inferior parietal cortex. The severity of space motion sickness symptoms was found to correlate with a post-to pre-flight difference in connectivity between the right supramarginal gyrus and the left anterior insula. Due to the complex nature and rapid dynamics of adaptation to gravity alterations, the post-flight findings might be attributed to both the long-term microgravity exposure and to the readaptation to Earth's gravity that took place between the landing and post-flight MRI session. Nevertheless, the results have implications for the multisensory reweighting and gravitational motor system theories, generating hypotheses to be tested in future research.

Motor rehabilitation is one of the key tasks for the recovery of personal independence of patients suffering a stroke. Neuromuscular electrostimulation synchronized with the performance of a motor task, known as functional electrical stimulation (FES), is a proven and widely used method. Specialists have established the principles of safe neuromuscular stimulation, as well as the methods aimed at increasing strength in affected muscles, over more than a 40-year history of FES studies. This review presents information about the novel FES technologies, clinical and basic studies, and discusses prospects for future research areas.

Dry immersion (DI) is acknowledged as a reliable space flight analog condition. At DI, subject is immersed in water being wrapped in a waterproof film to imitate microgravity (μG). Microgravity is known to decrease muscle tone due to deprivation of the sensory stimuli that activate the reflexes that keep up the muscle tone. In contrary, parkinsonian patients are characterized by elevated muscle tone, or rigidity, along with rest tremor and akinesia. We hypothesized that DI can diminish the elevated muscle tone and/or the tremor in parkinsonian patients. Fourteen patients with Parkinson's disease (PD, 10 males, 4 females, 47-73 years) and 5 patients with vascular parkinsonism (VP, 1 male, 4 females, 65-72 years) participated in the study. To evaluate the effect of DI on muscles' functioning, we compared parameters of surface electromyogram (sEMG) measured before and after a single 45-min long immersion session. The sEMG recordings were made from the biceps brachii muscle, bilaterally. Each recording was repeated with the following loading conditions: with arms hanging freely down, and with 0, 1, and 2 kg loading on each hand with elbows flexed to 90°. The sEMG parameters comprised of amplitude, median frequency, time of decay of mutual information, sample entropy, correlation dimension, recurrence rate, and determinism of sEMG. These parameters have earlier been proved to be sensitive to PD severity. We used the Wilcoxon test to decide which parameters were statistically significantly different before and after the dry immersion. Accepting the p < 0.05 significance level, amplitude, time of decay of mutual information, recurrence rate, and determinism tended to decrease, while median frequency and sample entropy of sEMG tended to increase after the DI. The most statistically significant change was for the determinism of sEMG from the left biceps with 1 kg loading, which decreased for 84% of the patients. The results suggest that DI can promptly relieve motor symptoms of parkinsonism. We conclude that DI has strong potential as a rehabilitation method for parkinsonian patients.

BACKGROUND:the relevance of this study arises from the high prevalence of upper limb motor impairment and pathological synergy in the post-stroke patients; these conditions are very difficult to correct with the use of the traditional rehabilitation methods. A promising but insufficiently studied approaches are the virtual reality (VR) technology as well as its combination with other techniques.AIM:The objective of the present study was to evaluate the influence of the training making use of the mechanotherapeutic system on the motor function of the paretic hand.MATERIAL AND METHODS:A total of 30 patients were enrolled in this study. The main group comprised 20 of them who completed the training course on the mechanotherapeutic system allowing for separate adjustment of weight support for the shoulder and the forearm, VR feedback with individual setting of the active working space, and augmented functional exercises. The control group consisted of the patients (n=10) who performed the task-oriented motor training course of an equal duration with arm weight support and visual feedback.RESULTS AND DISCUSSION:The assessment based on the Fugl-Meyer scale (FMA) showed the statistically significant changes in the passive motion range in the patients of both groups, but only those comprising the main group were found to experience the improvement of the major movements of the arm, wrist, and hand as well as movements outside synergy (p<0.005). Fine motor skills estimated from the results of the Action Research Arm test (ARAT) improved only in the main group due to the cylindrical and pinch grip (p<0.005). Also, only patients of the main group, improved daily living skills evaluated based on the Frenchay Arm test (FAT) (p<0.005).CONCLUSION:The results of the present study give evidence that the use of combined training with arm weight support and VR feedback contributes to a more complete recovery of motor and daily living skills in the upper limb of post-stroke patients, compared to the classical task-oriented training with visual feedback.

In recent decades, interest in studies on basic and applied aspects of how the nervous system functions has been growing rapidly around the world. The recovery of lost functions rests on processes of neuroplasticity, which is determined by the ability of the brain to transform its structures in response to injury. The effects of both routine and state-of-the-art neurorehabilitation technologies are ensured by synaptic plasticity— long-term potentiation and long-term depression, which influence learning and the preservation of new knowledge and skills obtained during rehabilitation. The introduction of new methods of neuroimaging, neurophysiology, and mathematical statistics have powerfully stimulated the development of the neuroplasticity doctrine. It has become clear that the main role in the recovery of injured functions is played by the reorganization of cortical nets and not by tissue reparation as such. The Research Center of Neurology has accumulated significant experience in the use of innovative treatment methods based on modern neurorehabilitation principles. Some of them are used for acute stroke; among other things, their effectiveness and safety have been shown with regard to patients in intensive care units (cyclic robotic mechanotherapy) and patients with severe motor deficit and an associated somatic pathology (stimulation of plantar support zones). Opportunities to assess neuroplasticity under various rehabilitation methods using fMRI and navigated transcranial magnetic stimulation (TMS) are revealed. The center also studies the fundamentals of consciousness using original neuroimaging and neurophysiological protocols for the sake of its recovery. The center is actively introducing its data into the practice of domestic clinics specializing in recovery medicine and neurorehabilitation.

Objectives. To assess the efficacy of using a brain–computer interface with a hand exoskeleton (BCI–exoskeleton) in the complex rehabilitation of patients with the sequelae of cerebrovascular accidents and to determine the minimally adequate reserves of cognitive functions required for the patient to carry out effective mental training using the movement imagination paradigm. Materials and methods. The study included 55 patients (median age 54.0 [44.0; 61.0] years, median time since stroke 6.0 [3.0; 13.0] months) in study and control (simulation of BCI) groups. The severity of paresis was evaluated on the Fugl–Meyer Assessment of Motor Recovery after Stroke (FMA) scale and the Action Research Arm Test (ARAT). Neuropsychological investigations to identify predictors for learning by movement imagination were carried out in 12 patients of the study group before training started. After investigations, patients received courses of movement imagination (hand extension) training using a BCI to control a hand exoskeleton. On average, patients received 10 30-min training sessions. After training, repeat assessments of parameters on motor scales were run, along with analysis of electroencephalography data obtained during training sessions; these results were compared with neuropsychological investigation data. Results and conclusions. Both groups showed improvements in upper limb motor function on the ARAT and Fugl–Meyer (sections A–D, H, I) scales. Only the BCI-exoskeleton group showed improvements in the ball grasp (p = 0.012), finger pinch grip (p = 0.012), and gross arm movements (p = 0.002) scores on the ARAT scale. A significant correlation was found between BCI movement quality indicators with various neuropsychological test results: Taylor figures, Head test, reaction choice test. Thus, inclusion of the BCI-exoskeleton system into the complex rehabilitation of patients with poststroke upper limb paresis significantly improves a number of measures of grasping and movement functions in the proximal segments of the upper limb. Use of neuropsychological tests as screening to select patients may help with the personalized application of rehabilitation technologies.

This review presents current data on possible mechanisms forming synergies in health, particularly at the cortical level. The mechanisms of formation of pathological synergies, taking account of the anatomical and physiological characteristics of the upper limbs and the hypothesis, that synergistic patterns are transformed in patients with spastic hemiparesis are discussed. Current views of the pathophysiological bases of the formation of pathological synergies based on neuroimaging and neurophysiological study data are presented, along with a method for noninvasive stimulation of the brain. The question of the correction and transformation of pathological synergies in rehabilitation practice is discussed. Particular attention is paid to clinical and instrumented evaluation of synergies and the use of validated clinical scales and instrumented methods such as video movement analysis, electromyography, magnetic and contactless tracking systems, and virtual reality technologies.

The mechanisms of the organization of goal-directed movements in the human arm have received insufficient study. The processes of cortical reorganization on the background of learning new skills and rehabilitation after central nervous system disease are of particular interest. Studies of the motor system and recording of neurophysiological parameters determining the kinematic characteristics of movements at the cortical level use navigated transcranial magnetic stimulation. The present study of 20 healthy volunteers randomized to study and control groups assessed resting motor thresholds, cortical motor representation zones of the extensor digitorum communis muscle in terms of areas and weighted areas, and the displacement of the centers of gravity on the background of training to motor imagery using a brain–computer interface. No significant differences were found between these parameters in the study group and the control group.

Authors review the milestones of the historical formation of various theories of motor control, from the reflex to the system model. These theories form the basis forь the methods and approaches of motor rehabilitation of patients with neurological diseases and injuries. The task-oriented approach, based on systemic theories of motor control, is now generally accepted. One of its main fundamentals is the dependence of movement on parameters and conditions of the motor under performance. Rehabilitation methods and approaches presented in this paper are not mutually exclusive, but supportive. This is the reason why the study of effectiveness of a particular rehabilitation method does not always yield valuable results. Various rehabilitation methods and approaches should be combined in the treatment of neurological patients. Moreover, relative contribution of individual methods into the rehabilitation of each patient may vary depending on the safety of his or her motor functions and many other factors that are to be taken into account when planning rehabilitative activities.

Purpose: The purpose of this study was to test the effects of navigated repetitive transcranial magnetic stimulation, delivered in different modes, on motor impairments and functional limitations after stroke. Methods: The study sample included 42 patients (58.5 ± 10.7 years; 26 males) who experienced a single unilateral stroke (1–12 months previously) in the area of the middle cerebral artery. Patients completed a course of conventional rehabilitation, together with 10 sessions of navigated repetitive transcranial magnetic stimulation or sham stimulation. Stimulation was scheduled five times a week over two consecutive weeks in an inpatient clinical setting. Patients were randomly assigned to one of four groups and received sham stimulation ( n = 10), low-frequency (1-Hz) stimulation of the nonaffected hemisphere ( n = 11), high-frequency (10-Hz) stimulation of the affected hemisphere ( n = 13), or sequential combination of low- and high-frequency stimulations ( n = 8). Participants were evaluated before and after stimulation with clinical tests, including the arm and hand section of the Fugl–Meyer Assessment Scale, modified Ashworth Scale of Muscle Spasticity, and Barthel Index of Activities of Daily Living. Results: Participants in the three groups receiving navigated repetitive transcranial magnetic stimulation showed improvements in arm and hand functions on the Fugl–Meyer Stroke Assessment Scale. Ashworth Scale of Muscle Spasticity and Barthel Index scores were significantly reduced in groups receiving low- or high-frequency stimulation alone. Conclusions: Including navigated repetitive transcranial magnetic stimulation in a conventional rehabilitation program positively influenced motor and functional recovery in study participants, demonstrating the clinical potential of the method. The results of this study will be used for designing a large-scale clinical trial.