Among the various brain–computer interface (BCI) modifications used in post-stroke rehabilitation, BCI systems combined with functional electrical stimulation (FES) are considered the most effective. As a preliminary step toward optimizing such systems for clinical application, it remains unclear whether using electroencephalography (EEG) alone versus a hybrid EEG and functional near-infrared spectroscopy (fNIRS) approach affects real-time three-class BCI–FES control performance in healthy individuals. In a blind randomized study, 16 healthy volunteers completed five BCI–FES training sessions across three days. In one group, FES of wrist extensor muscles was driven by a hybrid EEG–fNIRS classifier; in the other, by EEG only. Classification accuracy, sense of agency, attention, and physical comfort were assessed. No statistically significant between-group differences were found in any outcome measure (p > 0.05). Median real-time three-class classification recall was 53.5% in the hybrid group and 57.3% in the EEG-only group. The median agency score reached approximately 75% of the maximum possible value in both groups. Simulation analysis showed comparable accuracy for unimodal fNIRS-only and EEG-only classifiers. Genetic algorithm-based channel selection identified C3 and C4 as the most informative EEG channels, while optimal fNIRS placement required individual optimization. Within the constraints of the classification and fusion pipeline used here, these findings suggest that signal acquisition modality does not significantly influence BCI–FES performance or sense of agency in healthy subjects. The complete EEG–fNIRS dataset is publicly available through NITRC.

Introduction. In clinical practice, a comprehensive assessment of the systems responsible for balance is important both for correct diagnosis and the right choice of therapy. To provide accurate assessment of all the systems involved in balance control, in 2009, F.B. Horak et al. from the Oregon Health and Sciences University developed a universal Balance Evaluation Systems Test (BESTest) consisting of 36 tasks. Subsequently, the authors improved this method by selecting 14 tasks that evenly belonged to four of the six sections of the original BESTest, which collectively constituted the Mini-BESTest. The Mini-BESTest is a unique brief assessment tool that is actively used worldwide for the diagnostics and dynamic evaluation of balance in various nervous system disorders. However, the absence of a validated Russian version makes it challenging to use this test in Russia. The objective of the study is to develop an official Russian version (cultural and linguistic adaptation) of the Mini-BESTest to consider the target language and culture (1st stage of the linguistic validation study). Materials and methods. The author of the test, F.B. Horak, granted her consent for the linguistic validation of Mini-BESTest in Russia. Forward and backward translations of the test and its materials, pilot testing (cognitive debriefing), and development of the Russian version were carried out with the participation of a linguistic philologist and neurologists specializing in working with patients with balance disorders in various neurological diseases. Results. Based on the results of the expert committee meeting, a cultural and linguistic adaptation of the test was carried out and the final Russian version presented in this article was approved. Conclusion. The first developed Russian version of Mini-BESTest is officially presented and recommended for use both in clinical and research practice in Russia and other Russian-speaking countries. The psychometric properties (reproducibility, inter-rater reliability, and sensitivity of the test) of the Russian version are currently being assessed.

Understanding patterns of interhemispheric asymmetry is crucial for monitoring neuroplastic changes during post-stroke motor rehabilitation. However, conventional laterality indices often pose computational challenges when applied to functional near-infrared spectroscopy (fNIRS) data due to the bidirectional hemodynamic responses. In this study, we analyze fNIRS recordings from 15 post-stroke patients undergoing motor imagery brain–computer interface training across multiple sessions. We compare traditional laterality coefficients with a novel task response asymmetry coefficient (TRAC), which quantifies differential hemispheric involvement during motor imagery tasks. Both indices are calculated for oxygenated and deoxygenated hemoglobin responses using general linear model coefficients, and their day-to-day dynamics are assessed with linear regression. The proposed TRAC demonstrates greater sensitivity than conventional measures, revealing significantly higher oxygenated hemoglobin TRAC values (0.18 ± 0.19 vs. −0.05 ± 0.20, p < 0.05) and lower deoxygenated hemoglobin TRAC values (−0.15 ± 0.27 vs. 0.04 ± 0.23, p < 0.05) in lesioned compared to intact hemispheres. Among patients who exhibit substantial motor recovery, distinct daily TRAC dynamics were observed, with statistically significant temporal trends. Overall, the novel TRAC metric offers enhanced discrimination of interhemispheric asymmetry patterns and captures temporal neuroplastic changes not detected by conventional indices, providing a more sensitive biomarker for tracking rehabilitation progress in post-stroke brain–computer interface applications.

AbstractThis paper presents an open dataset of over 50 hours of near infrared spectroscopy (NIRS) recordings. Fifteen stroke patients completed a total of 237 motor imagery brain–computer interface (BCI) sessions. The BCI was controlled by imagined hand movements; visual feedback was presented based on the real– time data classification results. We provide the experimental records, patient demographic profiles, clinical scores (including ARAT and Fugl–Meyer), online BCI performance, and a simple analysis of hemodynamic response. We assume that this dataset can be useful for evaluating the effectiveness of various near– infrared spectroscopy signal processing and analysis techniques in patients with cerebrovascular accidents.

High proprioceptive sensitivity is an important factor in the efficiency of technical elements and athletic performance in many sports. However, proprioceptive control of the positions of upper limb segments and muscle effort in wrestlers has hardly been investigated. The purpose of this article was to study the reproduction accuracy of hand position and muscle effort during discrete contraction and relaxation of the forearm muscles in sambo athletes. Materials and methods. The research involved young sambo wrestlers (n = 10) and nonathletes (control, n = 15). We evaluated the reproduction accuracy of forearm pronation/supination angles (20, 50 and 80°) using a PABLO Handsensor (Tyromotion, Austria) and the accuracy of isometric muscle contraction during static pronation/supination, using a stationary hand joystick, in the ascending and descending directions of effort development (0, 20, 50 and 80 % of the maximum effort) according to the level of electromyographic activity of forearm pronators and supinators (Trust-M functional electrical stimulation system, Neurocore, Russia). Results. We found that proprioceptive control of forearm position accuracy and static effort during the contraction of forearm pronators and supinators did not differ between wrestlers and non-athletes. However, the absolute reproducibility error of 50 and 80 % of muscle effort during discrete relaxation of the pronators was lower (p < 0.01) in wrestlers than in non-athletes. Moreover, in the general sample, effort reproduction accuracy at pronators’ discrete contraction was higher than at discrete relaxation, which indicates a deficit of proprioceptive control of muscle effort during relaxation. Thus, exercising upper limb muscles in sambo improves proprioceptive control of discrete muscle relaxation. Further studies should determine the role of the established phenomenon in the effectiveness of wrestling skills and sports results.

Introduction. Similar asymmetric patterns of motor disorders and neurophysiological changes complicate the differential diagnosis between multifocal motor neuropathy (MMN) and multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) as two chronic dysimmune neuropathies with significantly different treatment approaches. The lack of specific paraclinical markers often result in misdiagnosis and selection of ineffective specific therapy. Identification of specific neuroimaging biomarkers to differentiate these conditions may improve diagnostic approaches. Objective: To identify neuroimaging markers for the differential diagnosis between MMN and MADSAM. Materials and methods. The study included 65 participants, particularly 30 individuals with MMN and 35 individuals with MADSAM followed up in the Center of Peripheral Nervous System Diseases, Research Center of Neurology, Moscow, Russia. We retrospectively analyzed their clinical and epidemiological characteristics as well as ultrasonography and magnetic resonance imaging (MRI) findings. Results. Ultrasonography was performed on the peripheral nerves of the upper extremities, the spinal nerves, and the brachial plexus. The results showed that participants with MADSAM had significantly greater cross-sectional areas (CSAs) and a higher incidence of intraneural ultrasonographic abnormalities compared to participants with MMN. CSA thresholds of the median nerves were identified using ROC analysis to differentiate between MMN and MADSAM. MRI scans of the brachial plexus revealed no abnormalities in 41.4% of the individuals with MMN and 27.3% of the individuals with MADSAM. Meanwhile, STIR hyperintense signal from the brachial plexus was most typical ( 70%) for the MADSAM group. Conclusions. This was the first detailed comparative analysis of neuroimaging findings in a large sample of patients with either MMN or MADSAM in Russia. Ultrasonographic markers for differential diagnosis have been determined. The advantages and limitations of ultrasonography and MRI of the brachial plexus and the spinal and peripheral nerves in diagnosing multifocal chronic dysimmune neuropathies have been demonstrated.

Introduction. Cerebral small vessel disease (CSVD) is one of the leading causes of vascular and mixed cognitive impairment (CI). Treatment options for CSVD-associated CI are limited. Repetitive transcranial magnetic stimulation (rTMS) is a promising non-drug treatment option. The aim of the study was to evaluate the effects of 10 rTMS sessions of the left dorsolateral prefrontal cortex (DLPFC) on cognitive functions in CSVD patients. Materials and methods. The study included 30 patients with CSVD and moderate CI randomized to the active (DLPFC stimulation; n = 20) and control (vertex stimulation; n = 10) groups. Both groups received 10 sessions of high-frequency rTMS. The DLPFC target was selected based on the individual paradigm fMRI data with a focus on executive functions. Cognitive function was assessed using the Montreal Cognitive Assessment Scale (MoCA), the Trail Making Test (TMT), the Tower of London Test, and the Rey–Osterrieth Complex Figure Test before, immediately after, and 3 months after the stimulation. Adverse events were assessed using standardized questionnaires. Results. The active group showed a significantly better effect compared to the control group according to MoCA, TMT A and B, The Tower of London Test, delayed recall on the Rey–Osterrieth Complex Figure Test immediately after the stimulation and MoCA, TMT A and B and The Tower of London 3 months after the stimulation. Adverse events in the study were mild and did not affect treatment adherence. Conclusion. rTMS is a promising, safe, and well-tolerated treatment option for mild cognitive impairment in CSVD. However, additional research is needed to make recommendations for its clinical use.

Background. In recent decades, the phenomenon of “covert cognition” has been described in a small proportion of patients with chronic disorders of consciousness. Specialized paradigms (tasks) are being developed to detect it mostly abroad. These paradigms are carried out under the control of various instrumental methods. The Russian researchers are faced with the task of validating already established paradigms on the Russian-speaking population and of creating new ones. Neuropsychological approach can contribute to solving these problems. Objectives. The study was aimed at developing a set of paradigms to detect the “covert cognition” phenomenon in a Russian-speaking sample of patients using functional magnetic resonance imaging. Methods. The development of paradigm sets was based on the analysis of previous studies and on neuropsychological data. Results. The hierarchical complex proposed by the authors includes twelve paradigms. Nine of them are passive, aimed at perceiving stimuli of different modalities. These are somatosensory (painful stimulus, “writing” a letter on the abdomen), auditory non-speech (alarm clock, two musical fragments without words, child’s laughter) and auditory speech (narratives in native and unfamiliar languages, name within the “cocktail party” effect, audio fragment from the film with obscene language) stimuli. The other three paradigms are active, aimed at encouraging people to follow instructions (imagining spatial navigation, cleaning teeth and singing to themselves). Their theoretical justification is given. Conclusions. The developed set of paradigms covers various aspects of cognitive functioning. The results of its testing on healthy volunteers and patients with chronic disorders of consciousness to detecting the “covert cognition” phenomenon will be presented in subsequent publications.

High proprioceptive sensitivity is an important factor in the efficiency of technical elements and athletic performance in many sports. However, proprioceptive control of the positions of upper limb segments and muscle effort in wrestlers has hardly been investigated. The purpose of this article was to study the reproduction accuracy of hand position and muscle effort during discrete contraction and relaxation of the forearm muscles in sambo athletes. Materials and methods. The research involved young sambo wrestlers (n = 10) and nonathletes (control, n = 15). We evaluated the reproduction accuracy of forearm pronation/supination angles (20, 50 and 80°) using a PABLO Handsensor (Tyromotion, Austria) and the accuracy of isometric muscle contraction during static pronation/supination, using a stationary hand joystick, in the ascending and descending directions of effort development (0, 20, 50 and 80 % of the maximum effort) according to the level of electromyographic activity of forearm pronators and supinators (Trust-M functional electrical stimulation system, Neurocore, Russia). Results. We found that proprioceptive control of forearm position accuracy and static effort during the contraction of forearm pronators and supinators did not differ between wrestlers and non-athletes. However, the absolute reproducibility error of 50 and 80 % of muscle effort during discrete relaxation of the pronators was lower (p < 0.01) in wrestlers than in non-athletes. Moreover, in the general sample, effort reproduction accuracy at pronators’ discrete contraction was higher than at discrete relaxation, which indicates a deficit of proprioceptive control of muscle effort during relaxation. Thus, exercising upper limb muscles in sambo improves proprioceptive control of discrete muscle relaxation. Further studies should determine the role of the established phenomenon in the effectiveness of wrestling skills and sports results.

Introduction. Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterized by long-term progressive or relapsing course, neurological deficit, and disability of varied severity. The course of CIDP after specific therapy and, if necessary, long-term maintenance treatment are to be studied. Objective: To evaluate CIDP clinical and history characteristics over the long-term follow-up ( 5 years), to compare long-term CIDP course in a number of clinical variants and onset types, and to determine clinical predictors of unfavorable CIDP course. Materials and methods. The study included 45 patients diagnosed with CIDP based on EAN/PNS 2021 criteria lasting for 5 or more years. Retrospective collection and analysis of medical records and clinical history were performed. Internationally accepted scales were used to assess neurological deficit (NIS, MRCss), disability (INCAT), and disease activity status (CDAS). The criteria of unfavorable course were developed to evaluate factors affecting CIDP course. Results. Among the patients with CIDP history of 5 years, each third (34%) had no neurological deficit and remained in long-term clinical remission (CDAS 1). The vast majority (90%) responded to first-line therapy in early disease, while only 53% of patients required maintenance treatment in 5 or more years of the onset. With the developed criteria (poor response to glucocorticosteroids (GCS), need for maintenance therapy, and CDAS 3–5), unfavourable CIDP course was detected in 24 (53.3%) participants. Its probability increased in later onset (47 [30; 50] years), the chronic type of onset, and delayed specific therapy. The most significant predictors included low total NIS score at onset (60 points) and multifocal CIDP. Conclusions. The course of typical CIDP is relatively favorable if timely diagnosed, and pathogenetic treatment initiated. Patients with acute and subacute onset demonstrate the best long-term status. The predictors of unfavourable disease course include mild neurological deficit at onset (NIS total score 60 points) and multifocal CIDP.

BACKGROUND: A validated tool for assessing the quality of life specific to a particular disease has not yet been developed. Previous studies only partially investigated the quality of life of patients with craniovertebral junction meningiomas and did not include the entire spectrum of functional disorders in this disease. AIM: To develop and validate a questionnaire to assess the quality of life of patients with craniovertebral junction meningiomas. MATERIALS AND METHODS: A retrospective and prospective study of 119 patients with craniovertebral junction meningiomas was conducted before and after surgical and combined (surgical removal of the tumor followed by radiation therapy) treatment using a validated questionnaire developed. RESULTS: A quality of life questionnaire for patients with craniovertebral junction meningiomas was developed and validated. Determining the internal consistency of the scale showed that the Cronbach alpha coefficient was α=0.78 (p 0.001), confirming its sufficient level. In analyzing the sensitivity of the questionnaire, the estimates before and after surgery did not differ significantly (p=0.62, t-criterion). CONCLUSIONS: This study developed the first quality of life questionnaire worldwide for patients with craniovertebral junction meningiomas. In summary, this questionnaire is not able to reflect the dynamics of the quality of life.

Background. The authors developed a specialized set of functional magnetic resonance imaging paradigms, based on data from general psychology, neuropsychology and previous studies, to diagnose the “covert cognition” phenomenon on a Russian-speaking sample of patients with chronic disorders of consciousness. Before using this set with patients, it is advisable to carry out testing on a group of healthy people with preserved consciousness in order to detect significant clusters of activation corresponding to paradigms and to assess their reproducibility at the individual level. Objectives. The study is aimed at testing the proposed set of fMRI paradigms in order to detect the “covert cognition” phenomenon on a sample of healthy volunteers. Study Participants. Sample included 10 healthy volunteers (3 men, 7 women, M = 44 years, SD = 17). Methods. The study was performed on a magnetic resonance imaging scanner “Magnetom Verio”, “Siemens” with a magnetic field strength of 3 Tesla. The hierarchical set of nine passive and three active paradigms was presented to participants. Statistical analysis was carried out using SPM12. Results. As a result of group analysis, significant clusters of activation were observed in six passive paradigms, covering the perception of tactile (“writing” a letter on the abdomen), auditory non-speech (alarm clock, two musical fragments without words) and speech stimuli. Auditory speech paradigms (audio fragment from the film with obscene language, testee`s name within the “cocktail party” effect) were the most reproducible paradigms at the individual level. Conclusions. The obtained results allow us to apply the proven paradigms in further studies to detecting the “covert cognition” phenomenon on a Russian-speaking sample of patients with chronic disorders of consciousness. Data on brain activation in healthy volunteers in different paradigms enriches theoretical understanding of cerebral organization of cognitive functions.

Introduction. Cognitive impairment (CI) is a common manifestation of multiple sclerosis (MS), which significantly affects patients’ daily life and professional activity. Despite the development of methods to screen MS patients for CI, data on its prevalence in the Russian population are still lacking. Aim: to comprehensively assess cognitive functions in patients with different types of MS. Materials and methods. The study included MS patients who did not have any other possible causes of CI and no diseases or conditions that confounded this assessment. CI was determined using the Brief International Cognitive Assessment in Multiple Sclerosis (BICAMS) test battery and the Stroop test as a decrease in the scores below the mean by at least 1.5 standard deviations. CI was subjectively assessed using the Perceived Deficit Questionnaire; fatigue was subjectively assessed using the Modified Fatigue Impact Scale (MFIS). The Mann–Whitney test and Fisher’s exact test were used for comparison, and the Spearman test was used to evaluate correlations. Results. We evaluated 77 MS patients (30 men; age 40 [30; 48] years; 47 with relapsing-remitting MS, 30 with progressive MS). CI incidence was 23.4% in patients with relapsing-remitting MS and 77% in patients with progressive MS, while multi-domain CI was statistically significantly more common in patients with progressive MS. Impairment of processing speed was the most common. Patients with relapsing-remitting MS and CI were statistically significantly older and had longer disease duration than those without CI. There was a statistically significant correlation of subjective CI severity with MFIS scores but not with testing results. Conclusion. CI incidence in MS patients was relatively high with greater severity and involvement of more domains in patients with progressive MS. No correlation was found between subjective and objective CI assessment results, which may suggest that patients underestimated their deficit.

INTRODUCTION. Central post-stroke pain (CPSP) is a neuropathic pain syndrome that results from damage to the central somatosensory system as a result of a cerebral circulation disorder. Up to half of patients do not achieve a clinically significant reduction in pain intensity when using anticonvulsants and antidepressants. Neuromodulation technologies are an alternative to pharmacotherapy. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation method based on the excitation of neurons in the stimulated area induced by a high-induction alternating magnetic field. The effects of rTMS are mediated through synaptic plasticity-like mechanisms, as well as changes in the secretion of endogenous opioids and dopamine. OBSERVATIONS. The most studied and effective rTMS target is the primary motor cortex contralateral to the localization of pain. Among the other studied targets, a significant effect has been shown only for the stimulation of secondary somatosensory cortex. An effect has been demonstrated for high-frequency protocols, while low-frequency rTMS is not effective. The duration of the effect of one session can reach 3 hours, and a series of sessions up to several weeks. The use of maintenance sessions allows extending the effect up to 1 year. Clinical characteristics of the pain syndrome, parameters of intracortical interactions, and preservation of thalamocortical pathways can be used as predictors of rTMS efficacy. CONCLUSION. Repetitive transcranial magnetic stimulation is a promising and safe method that has an extensive evidence base of effectiveness in CPSP.

Background:Hypokalemic periodic paralysis (HypoKPP) is a rare neuromuscular genetic disorder causing recurrent episodes of flaccid paralysis. Most cases are associated with CACNA1S mutation, causing defect of calcium channel and subsequent impairment of muscle functions. Due to defined management approaches early diagnosis is crucial for promptly treatment and prevention new attacks.Materials and methods:We report a case of HypoKPP associated with previously unreported mutation in CACNA1S gene (p.R900M). Molecular modeling of CaV1.1 was applied to evaluate its pathogenicity.Results:As a patient referred between attacks neurological status, laboratory and neurophysiological examination were unremarkable. Molecular modeling predicted that the p.R900M mutation affects the process of calcium channels activation.Conclusion:Novel CACNA1S mutation, associated with HypoKPP was identified. Monte-Carlo energy minimization of the CaV1.1 model supported the association of this mutation with this disease.

Introduction. Non-invasive brain–computer interfaces (BCIs) enable feedback motor imagery [MI] training in neurological patients to support their motor rehabilitation. Nowadays, the use of BCIs based on functional near-infrared spectroscopy (fNIRS) for motor rehabilitation is yet to be investigated. Objective: To evaluate the potential fNIRS BCI use in hand MI training for comprehensive post-stroke rehabilitation. Materials and methods. This pilot study included clinically stable patients with mild-to-moderate post-stroke hand paresis. In addition to the standard rehabilitation, the patients underwent 10 nine-minute MI fNIRS BCI training sessions. To evaluate the quality of fNIRS BCI control, we assessed the percentage of time during which the classifier accurately detected patient's mental state. We scored the hand function using the Action Research Arm Test (ARAT) and the Fugl-Meyer Assessment (FMA). Results. The study included 5 patients at 1 day to 12 months of stroke. All the participants completed the study. All study participants achieved BCI control rates higher than random (41–68%). While three patients demonstrated the clinically significant improvements in their ARAT scores, one of them also showed an improvement in the FMA score. All the participants reported experiencing drowsiness during training. Conclusions. Post-stroke patients can operate the fNIRS BCI system under investigation. We suggest adjusting the feedback system, extending the duration of training, and incorporating functional electromyostimulation to enhance training effectiveness.

Introduction. Despite the improving diagnostic criteria for the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), its verification is still an issue. Objective: to study the rate and the causes of CIDP misdiagnosis. Materials and methods. We prospectively and retrospectively analyzed the clinical and paraclinical data of 223 patients admitted to the Research Center of Neurology from 2018 to 2022 with a CIDP referral. Results. We revised the CIDP diagnosis in 150/223 patients (67%; median age 55.5 [43; 63] years; 75 males and 75 females; 3-year follow-up history [1.75; 5.25].) Once the definitive diagnosis was clarified, we divided the patients into the following groups: polyneuropathy of other etiology (n = 94; 63%), other neuromuscular disorders (n = 39; 27%), CNS disorders (n = 10; 7%), no structural NS disease (n = 7; 5%). Patients did not meet the 2021 EAN/PNS diagnostic criteria at the history-taking stage in 65% of cases, at the neurological examination stage in 39% of cases, and at the electroneuromyography stage in 92% of cases. Conclusions. The rate of CIDP misdiagnosis in Russia is 67%, and most often this refers to patients with polyneuropathy of other etiologies. The main cause for the CIDP misdiagnosis was inaccurate electroneuromyography. We should bear in mind that CIDP is a rare disorder with an extensive differential diagnosis, so it should be verified according to the current 2021 EAN/PNS diagnostic criteria.