[A two-year prospective longitudinal study of the dynamics of cognitive functions in different periods of stroke]. / Dvukhletnee prospektivnoe prodol'noe issledovanie dinamiki kognitivnykh funktsii v razlichnye periody insul'ta.

OBJECTIVE: To examine the dynamics of cognitive functions 3, 6, 12, and 24 months after ischemic stroke (IS). MATERIAL AND METHODS: The study included 32 patients (women 21.4%), aged 40-71 years (mean age 58.7 years), with IS less than 3 months old and a moderately pronounced decrease in activity in everyday life. At four visits (baseline, after 12, 36, 84 weeks), a neuropsychological examination of cognitive functions was carried out using a 10-point system (1 point - maximum impairment, 10 points - no impairment), testing according to the Barthel scale, the National Institutes of Health Stroke Scale (NIHSS), the modified Rankin scale (mRs). During the study, patients received unified basic therapy and underwent multimodal rehabilitation courses. RESULTS: When assessing cognitive functions in the period 3-6 months after IS, there was a significant (p<0.05) improvement in memory (6.5±0.62 to 8.0±0.74 points), attention (5.7±0.58 to 7.2±0.73 points), praxis (7.9±0.78 to 9.1±0.85 points), speech (6.5±0.67 to 7.5±0.87 points); a significant increase in the average Barthel score (65.8±5.4 to 89.2±8.6) was accompanied by a significant decrease in neurological deficit (7.7±0.51 to 5.3±0.33 NIHSS points and 3.9±0.28 to 2.6±0.15 mRs points). In the period 6-12 months after IS, significant disturbances were detected in the areas of memory, attention and thinking. Cognitive function continued to deteriorate 12-24 months after IS. In the period 6-24 months after IS, no significant changes in the average values on the Barthel, NIHSS, and mRs were detected. CONCLUSION: The most favorable interval for the recovery of cognitive functions in patients after IS is the early recovery period. As the time after a stroke increases, the ability to recovery cognitive functions decreases.

[Rehabilitation of patients with post-stroke cognitive impairment using the P300-based brain-computer interface: results of a randomized controlled trial]. / Reabilitatsiya patsientov s postinsul'tnymi kognitivnymi narusheniyami s ispol'zovaniem interfeisa «mozg­komp'yuter¼ na volne P300: rezul'taty randomizirovannogo kontroliruemogo issledovaniya.

OBJECTIVE: To study the effects of a 10-day cognitive training using the brain-computer interface (BCI) technology at the P300 wavelength on the recovery of cognitive functions in poststroke patients. MATERIAL AND METHODS: The study included 30 patients, aged 22-82 years, with ischemic stroke less than 3 months old and moderate cognitive impairment (<26 points on the Montreal Cognitive Assessment Scale (MoCA)). All patients underwent neuropsychological testing, assessment of the presence of depression, assessment of activity in daily life. Patients were randomized into two groups: patients of group 1 (main) underwent a 10-day course of cognitive rehabilitation in the form of daily exercises in the BCI environment at the P300 wave equipped with a headset for recording an electroencephalogram (EEG). Patients of group 2 (control) received a standard set of rehabilitation measures. RESULTS: There was an increase in the mean score of the MoCA «Attention¼ domain in the main group of patients (2.3±1.24 to 5.2±1.16 points) compared with the control group (5.9±1.00 to 4.2±0.94 points, p<0.05). The results of covariance analysis with repeated measures, taking into account the factors «Visit¼ and «Group¼, the covariate «Depression¼ and «Number of training sessions¼ revealed significant effects for the MoCA domains «Naming¼ (p<0.05), «Attention¼ (p<0.05), «Abstraction¼ (p<0.05). By the end of the 10-day cognitive training using BCI, patients of the main group showed a significant increase in the number of entered letters (20.8±2.01 to 25.9±1.7 characters (p=0.02) compared with the control group (21.9±1.9 to 23.1±1.8, p=0.06). When comparing the number of words entered by patients after 10 days, a significant difference was found between the main and control groups (p<0.05). CONCLUSION: Rehabilitation of patients with post-stroke cognitive impairment using P300 BCI has a significant positive effect on the restoration of cognitive functions, primarily attention.

The use of epidural spinal cord stimulation in patients with chronic disorders of consciousness - neuroimaging and clinical results.

OBJECTIVE: Chronic disorders of consciousness are considered as a serious unresolved problem complicated by significant medical, social, and economic burden. Therefore, improving the conditions and facilitating the rehabilitation management of these patients is of particular interest. In recent years, interesting results of the use of spinal cord stimulation in patients with chronic disorders of consciousness appeared in the world literature, which makes the use of this technique promising in this category of patients. PATIENTS AND METHODS: We analyzed the results of high cervical spinal cord stimulation, both, in tonic and "Burst" modes, in 21 patients with chronic disorders of consciousness and severe spasticity managed in the last two years in FRCC ICMR. In 9 of them pre- and post-stimulation fMRI before and right after the stimulation was also performed for brain functional connectivity assessment. RESULTS: Improvement of the consciousness level was observed in 38.1% (n = 8) and a decrease in spasticity was obtained in 52.4% (n=11) of the patients. The difference in CRS-R score before and after spinal cord stimulation was statistically significant (p=0.028). The fMRI results revealed an increase in functional connectivity of the right anterior insula with several areas that are part of the Dorsal Attention, Visual and Default Mode networks after spinal cord stimulation. CONCLUSIONS: Epidural spinal stimulation at the upper cervical spine level demonstrated its effectiveness in patients with chronic diseases of consciousness of various etiology. Evaluation of the effect of specific stimulation modes requires further controlled study in larger group of patients.

[Regression of post-stroke aphasia and associated non-speech syndromes caused by a course of restorative treatment including intensive speech therapy]. / Regress postinsul'tnoi afazii i soputstvuiushchikh nerechevykh sindromov, obuslovlennyi kursom vosstanovitel'nogo lecheniia, vkliuchaiushchim intensivnuiu rechevuiu terapiiu.

AIM: To analyze clinical and fMRI indicators related with the therapeutic effectiveness of complex restorative treatment including intensive speech therapy in various clinical forms and severity of the aphasia syndrome. MATERIAL AND METHODS: The study included 40 right-handed patients with aphasia syndrome after the first hemispheric ischemic stroke. Patients were studied 3 month after disease onset. Patients were examined before and after rehabilitation treatment (4.7 weeks) including intensive speech therapy (15 hours of exercise per week). Evaluation of the effectiveness of treatment was carried out based on the dynamics of the results of neuropsychological, neurological and neuroimaging examinations of patients before and after treatment. The degree of recovery of speech and non-speech cognitive functions (based on the 10-point cognitive assessment, the dynamics of focal neurological deficit (NIHSS) and functional recovery of patients (Barthel index, modified Rankin scale) were assessed. Neuroimaging methods included structural MRI and two fMRI methods: fMRI resting state and fMRI equivalent of the evoked potentials of mismatch negativity (HP), using a sequence of standard and deviant sounds (Russian phonemes) to obtain the equivalent of HP. For statistical calculations, the program in Python version 3.6.0 was used. RESULTS: The maximum efficacy of restorative treatment (≥15% improvement in the scores of 10-point quantifying) was detected in 28 (70%) cases: 18 patients with initially severe and 10 patients with moderate aphasia, regardless of the clinical form of aphasia, and 11 patients with isolated sensory aphasia. Regression of speech and non-speech cognitive impairments in sensory aphasia was accompanied by a pronounced activation of intact speech homologues of the right hemisphere and the appearance of a small temporal and parietal region, which was small in volume and weak in intensity, similar in the localization to the norm. Regardless of the clinical form of aphasia, maximum therapeutic efficacy was accompanied by a reorganization of the speech neuronal rest network, which includes enhancement of both intra- and interhemispheric functional connectivity, with the predominance of amplification of the intra-hemispheric interactions of the posterior speech zones to the left while reducing their interhemispheric connectivity. Significant improvement in motor and sensory functions was detected in 9 (22%) patients with moderate contralateral spastic hemiparesis (p≤0.00) and did not correlate with the degree of regression of speech and non-speech focal cognitive impairments. A slight therapeutic effect was observed in 12 (30%) patients with mild to moderate speech and non-speech cognitive impairment. This effect was not correlated with a specific clinical form of aphasia. CONCLUSION: The maximum effectiveness of the 4.7 week restorative inpatient treatment, including intensive speech therapy (15 sessions per week), was obtained mainly with severe aphasia, and also with a specific clinical form - isolated sensory aphasia. According to the fMRI data, various compensatory reorganization of the neural speech network was detected, which probably reflects post stroke neuroplasticity associated with both the severity of aphasia and its specific clinical form.

[The prognosis for post-stroke aphasia]. / Prognoz postinsul'tnoi afazii.

AIM: To determine risk factors and factors of favorable prognosis for regression of post-stroke aphasia in the early recovery period of ischemic stroke (IS). MATERIAL AND METHODS: A cohort study was undertaken with 40 patients with different clinical forms of aphasia. The duration of study was 3-4 months of the disease. The regression of speech and non-speech cognitive impairment was assessed by the Method of a 10-point evaluation of higher mental functions. The method involves a comprehensive assessment of all mental functions with more than 90 subtests at the beginning and at the end of rehabilitation course and the calculation of the difference in the scoring of each mental function as a measure of treatment efficacy. Using logistic regression and odds ratio estimation, significance of the influence and the prognostic relationship of symptoms related to IS, and a number of biological and social factors (sex, age, and education) were studied. RESULTS: An independent prognostic value for the aphasia regression on the third month of disease has the severity of neurologic symptomatology (NIHSS score) for the first day of stroke (OR 3,27 95% CI 1,02-9,77) and the third month of the disease (p=0,005, OR 4,6, 95% CI [1,39-15,11]) and the decrease in daily activity assessed by the total score of the Barthel index (p=0,004, OR 3,92, 95% CI [1,01-15,21]). A number of MRI signs (localization of post-stroke changes in the left angular gyrus, frontal-temporal region and focal volume) had a significant effect on the dynamics of non-verbal cognitive impairment. Neuropsychological examination revealed a significant improvement of speech in patients with initially severe forms of aphasias, in particular, sensory and sensorimotor. A direct relationship between age and certain clinical forms of aphasia as well as a significant positive effect of duration (ß=1,91, p≤0,01) and level of education (ß=1,68, p≤0,007) on aphasia regression were determined. CONCLUSION: The severity of neurologic symptoms, in particular motor and sensory deficits, both in the acute and in the recovery period of the disease is one of the pathogenetic factors worsening the processes of functional reorganization of neuronal speech networks. The positive dynamics of the recovery of speech function is associated with the initial severity and clinical form of aphasia. The level and duration of education are related to factors positively affecting post-stroke neuroplasticity.

[Neuronet restructuring in focal and generalized epilepsy according to resting state fMRI]. / Neirosetevye perestroiki pri fokal'noi i generalizovannoi épilepsii po dannym fMRT pokoia.

AIM: To compare neuronet restructuring in focal and generalized epilepsy. MATERIAL AND METHODS: Seventy-seven patients, aged from 18 to 65 years, with the diagnosis of epilepsy, including 63 patients with focal epilepsy and 14 with generalized epilepsy, were examined. A control group included 23 healthy people. Neuronet restructuring was studied using fMRI. RESULTS AND CONCLUSION: According to resting state fMRI, there were between-group differences in spatial organization (activity map) of the brain structures as well as in the results of cross-correlation analysis of interaction maps of resting-state networks. It has been concluded that functional restructuring in connectomes in focal and generalized epilepsy have the opposite patterns of disorganization (toward increase or decrease) in most structures studied though there are structures with the same direction of connectivity changes.

[Functional neuroimaging of the brain structures associated with language in healthy individuals and patients with post-stroke aphasia]. / Funktsional'naia neirovizualizatsiia struktur mozga, sviazannykh s rech'iu v norme i pri postinsul'tnoi afazii.

The introduction of non-invasive functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI), in the practice of scientific and clinical research can increase our knowledge about the organization of cognitive processes, including language, in normal and reorganization of these cognitive functions in post-stroke aphasia. The article discusses the results of fMRI studies of functional organization of the cortex of a healthy adult's brain in the processing of various voice information as well as the main types of speech reorganization after post-stroke aphasia in different stroke periods. The concepts of 'effective' and 'ineffective' brain plasticity in post-stroke aphasia were considered. It was concluded that there was an urgent need for further comprehensive studies, including neuropsychological testing and several complementary methods of functional neuroimaging, to develop a phased treatment plan and neurorehabilitation of patients with post-stroke aphasia.

[The Connectomics: Neurophysiology, Achievements and Perspectives].

The review is devoted to researches in the relatively new field of neuroscience--connectomics. The theoretical and applied aspects of connectom studying are observed. The concept of connectom is defined as well as its attributes such as connectivity. The review describes the basic modern methods of the connectom investigation, existing data on the connectom structure in normal and pathological conditions, as well as prospects for the development of a new field of knowledge--connectomics.