Effects of virtual reality-based treadmill training on the balance and gait ability in patients after stroke

Gait and balance impairments contribute significantly to long-term disability after stroke. Modern concepts of stroke rehabilitation recommend a task-specific repetitive approach, such as using treadmill training. The purpose of this study was to investigate the effectiveness of using virtual reality-based treadmill training to improve balance and gait in subacute stroke patients. Twenty-two stroke patients were randomly stratified into two groups: the experimental (n = 11) and the control group (n = 11). Parameters associated with balance and gait were measured using the 6-minute walk test, the 10-meter walk test, the timed “up and go” test, the functional gait assessment, and the four square step test. Gait analysis using the zebris Rehawalk® treadmill system was also performed. Patients in the experimental group received virtual reality-based treadmill training five times a week for a period of four weeks, while those in the control group received treadmill training at the same frequency, duration, intensity, and structure, along with a progressively more difficult task demands. Significant improvements were observed in selected outcome measures in both groups after training. Patients in the experimental group experienced improvements in all of the spatiotemporal gait parameters, but there was a significant difference before and after training in duration of double support and lateral asymmetry. The findings of this pilot randomized controlled trial support the benefits of using a virtual reality-based treadmill training program to improve gait and balance in subacute stroke patients.

Power spectral densities of electroencephalographic theta and alpha frequency waves during information processing of language comprehension

A cross sectional study was conducted to assess electroencephalograph (EEG) Power Spectral Densities (PSD) of alpha and theta frequency bands for an integrative functional role of working memory (WM) in the architectonics of a synthesized and coordinated communication system as exemplified by the observable phenomenon of the evolved structured Language of Human Mind by using Visuo-Spatial Delayed Match to Sample (DMTS) task. The analysis exhibited significant Event Related Synchronization (ERS) along theta wave-form at temporal region along with Lateral Asymmetry Index (LAI) of Alpha Event Related Desynchronization (ERD) at parietal region suggestive of the phenomenal singularity of ERS of theta along temporal regions that seems to be intricately interwoven onto the spectacle of LAI of alpha ERD, presumably evolving a synthesized enveloped working memory, along the virtual phase-space of Human Mind and eventually translating into the comprehensible means of communication of Humans, i.e., Language.

Muscle activation strategies of people with early-stage Parkinson’s during walking

Introduction Some people with Parkinson’s disease (PD) frequently have an unsteady gait with shuffling, reduced strength, and increased rigidity. This study has investigated the difference in the neuromuscular strategies of people with early-stage PD, healthy older adults (HOA) and healthy young adult (HYA) during short-distance walking. Method Surface electromyogram (sEMG) was recorded from tibialis anterior (TA) and medial gastrocnemius (MG) muscles along with the acceleration data from the lower leg from 72 subjects—24 people with early-stage PD, 24 HOA and 24 HYA during short-distance walking on a level surface using wearable sensors. Results There was a significant increase in the co-activation, a reduction in the TA modulation and an increase in the TA-MG lateral asymmetry among the people with PD during a level, straight-line walking. For people with PD, the gait impairment scale was low with an average postural instability and gait disturbance (PIGD) score = 5.29 out of a maximum score of 20. Investigating the single and double support phases of the gait revealed that while the muscle activity and co-activation index (CI) of controls modulated over the gait cycle, this was highly diminished for people with PD. The biggest difference between CI of controls and people with PD was during the double support phase of gait. Discussion The study has shown that people with early-stage PD have high asymmetry, reduced modulation, and higher co-activation. They have reduced muscle activity, ability to inhibit antagonist, and modulate their muscle activities. This has the potential for diagnosis and regular assessment of people with PD to detect gait impairments using wearable sensors.

Isokinetic Profile of Elite Serbian Female Judoists

Elite judo athletes undergo vigorous training to achieve outstanding results. In pursuit of achieving competitive success, the occurrence of injuries amongst judo athletes is not rare. The study aimed to perform a knee flexors and extensors isokinetic torque analysis in elite female judo athletes. Fifty-eight elite female judo athletes of the Serbian national team (21.02 ± 3.11 years; 62.36 ± 11.91 kg, 165.04 ± 10.24 cm, training experience 12.72 ± 2.98 years) volunteered to participate in this study. The range of motion (ROM) was set at 90⁰. Testing was performed in a concentric–concentric mode for the testing speed of 60 ⁰/s. Five maximal voluntary contractions of knee extensors and knee flexors muscle groups were measured for both legs. The obtained data showed a statistically significant difference in absolute torque values among different categories as heavier athletes demonstrated higher values. Post hoc analysis showed a significant difference between weight categories, as heavier athletes demonstrated higher values, while no significant differences in normalized torque values for different weight categories were observed. The implementation of new elements and training modalities may improve performance and prevent lateral asymmetry, thus reducing the risk of injury.

Exploring the Brain Activity Related to Missing Penalty Kicks: An fNIRS Study

At vital moments in professional soccer matches, penalties were often missed. Psychological factors, such as anxiety and pressure, are among the critical causes of the mistakes, commonly known as choking under pressure. Nevertheless, the factors have not been fully explored. In this study, we used functional near-infrared spectroscopy (fNIRS) to investigate the influence of the brain on this process. An in-situ study was set-up (N = 22), in which each participant took 15 penalties under three different pressure conditions: without a goalkeeper, with an amiable goalkeeper, and with a competitive goalkeeper. Both experienced and inexperienced soccer players were recruited, and the brain activation was compared across groups. Besides, fNIRS activation was compared between sessions that participants felt anxious against sessions without anxiety report, and between penalty-scoring and -missing sessions. The results show that the task-relevant brain region, the motor cortex, was more activated when players were not experiencing performance anxiety. The activation of task-irrelevant areas was shown to be related to players experiencing anxiety and missing penalties, especially the prefrontal cortex (PFC). More particularly, an overall higher activation of the PFC and an increase of PFC lateral asymmetry were related to anxious players and missed penalties, which can be caused by players' worries about the consequences of scoring or missing the penalty kicks. When experienced players were feeling anxious, their left temporal cortex activation increased, which could be an indication that experienced overthink the situation and neglect their automated skills. Besides, the left temporal cortex activation is higher when inexperienced players succeeded to score a penalty. Overall, the results of this study are in line with the neural efficiency theory and demonstrate the feasibility and ecological validity to detect neurological clues relevant to anxiety and performance from fNIRS recordings in the field.

DETERMINATION OF CORRELATIONS BETWEEN SUBJECTS’ PSYCHOPHYSIOLOGICAL PARAMETERS AND THE RESULTS OF THE PERCEPTUAL EXPERIMENT

"Nowadays in Russia, there are insufficient systematized data on the degree of preparedness of medical students and graduates to interact with children with atypical development (AD). We have developed a methodological approach to assess the interaction of medical students with AD children. The work uses a perceptual experiment during which students are presented with test sequences containing speech signals of children with typical development (TD) and AD (Down syndrome, autism spectrum disorders). During the perceptual experiment, the listeners’ behavior was being video-recorded in parallel to verify their answers using the FaceReader software determining the true emotional state by their facial expression. The students’ psycho-emotional status was evaluated using a battery of psychological tests before and after the perceptual experiment. Additionally, the subjects’ psychophysiological and physiological parameters were determined. At the first stage of the work, the speech of 16 TD and AD children (11 boys and 5 girls) was used, the listeners were 25 1st-year pediatric students and 5 experts in the field of child speech. The statistical analysis revealed correlations between the listeners’ psychophysiological characteristics (Russian-native speakers): the profile of functional lateral asymmetry, formation indicators of the phonemic hearing, the coefficient of lateral preference by speech and the success in recognizing the children’s gender, age, psychoneurological state (TD – developmental disorders), and the severity of disorders in AD children. The acoustic parameters of words classified by experts as “legible” and “illegible” were determined. The work is financially supported by the Russian Science Foundation (project 19–78–00057)."

Impaired Cytoskeletal and Membrane Biophysical Properties of Acanthocytes in Hypobetalipoproteinemia – A Case Study

Familial hypobetalipoproteinemia is a metabolic disorder mainly caused by mutations in the apolipoprotein B gene. In its homozygous form it can lead without treatment to severe ophthalmological and neurological manifestations. In contrast, the heterozygous form is generally asymptomatic but associated with a low risk of cardiovascular disease. Acanthocytes or thorny red blood cells (RBCs) are described for both forms of the disease. However, those morphological changes are poorly characterized and their potential consequences for RBC functionality are not understood. Thus, in the present study, we asked whether, to what extent and how acanthocytes from a patient with heterozygous familial hypobetalipoproteinemia could exhibit altered RBC functionality. Acanthocytes represented 50% of the total RBC population and contained mitoTracker-positive surface patches, indicating the presence of mitochondrial fragments. While RBC osmotic fragility, calcium content and ATP homeostasis were preserved, a slight decrease of RBC deformability combined with an increase of intracellular free reactive oxygen species were observed. The spectrin cytoskeleton was altered, showing a lower density and an enrichment in patches. At the membrane level, no obvious modification of the RBC membrane fatty acids nor of the cholesterol content were detected but the ceramide species were all increased. Membrane stiffness and curvature were also increased whereas transversal asymmetry was preserved. In contrast, lateral asymmetry was highly impaired showing: (i) increased abundance and decreased functionality of sphingomyelin-enriched domains; (ii) cholesterol enrichment in spicules; and (iii) ceramide enrichment in patches. We propose that oxidative stress induces cytoskeletal alterations, leading to increased membrane stiffness and curvature and impaired lipid lateral distribution in domains and spicules. In addition, ceramide- and spectrin-enriched patches could result from a RBC maturation defect. Altogether, the data indicate that acanthocytes are associated with cytoskeletal and membrane lipid lateral asymmetry alterations, while deformability is only mildly impaired. In addition, familial hypobetalipoproteinemia might also affect RBC precursors leading to disturbed RBC maturation. This study paves the way for the potential use of membrane biophysics and lipid vital imaging as new methods for diagnosis of RBC disorders.

Concussion History and Neuromechanical Responsiveness Asymmetry

Context Detection of subtle changes in brain sensorimotor processes may enable clinicians to identify athletes who would derive the greatest benefit from interventions designed to reduce the risk for future injury and progressive neurologic or musculoskeletal dysfunction. Objective To develop a generalizable statistical model for identifying athletes who possess subtle alterations in sensorimotor processes that may be due to previous concussion. Design Cross-sectional study. Setting Residential Olympic Training Center sports medicine clinic. Patients or Other Participants A primary cohort of 35 elite athletes and a secondary cohort of 40 elite athletes who performed identical tests the preceding year. Intervention(s) Two upper extremity tests of visual-motor reaction time and 2 tests of whole-body reactive agility were administered. The whole-body tests required lateral or diagonal responses to virtual-reality targets, which provided measures of reaction time, speed, acceleration, and deceleration. Main Outcome Measure(s) Sport-related concussion history, which was reported by 54% (n = 19) of the athletes in the primary cohort and 45% (n = 18) of the athletes in the secondary cohort. Results Univariable analyses identified 12 strong predictors of sport-related concussion history, which we combined to create a composite metric with maximum predictive value. Composite lateral asymmetry for whole-body reactive movements and persisting effects of previous musculoskeletal injury yielded a logistic regression model with exceptionally good discrimination (area under the curve = 0.845) and calibration (predicted-observed probabilities within 7 subgroups: r = 0.959, P = .001). Application of the derived model to compatible data acquired from another cohort of elite athletes demonstrated very good discrimination (area under the curve = 0.772) and calibration (within 8 subgroups: r = 0.849, P = .008). Conclusions Asymmetry in whole-body reactive movement capabilities may be a manifestation of a subtle abnormality in the functional connectivity of brain networks that might be relevant to previously reported associations between sport-related concussion history and musculoskeletal injury occurrence.

Spatial variations of leaf morphometry in mangroves in La Havana, Cuba

Introduction: Mangroves represent 11 % of the emerged land of Cuba. There is no previous research describing foliar characteristics, but these variables can be used as health indicators in forest ecosystems. Objective: In the current study we describe folial morphometry in four mangroves around Havana city: Bajos de Santa Ana, Cojímar, Rincón de Guanabo and El Cobre – Itabo lagoon. Methods: We collected 1 472 leaves´ samples of Rhizophora mangle, Avicennia germinans and Laguncularia racemosa, between April and July in 2019, to extract eight foliar variables: length, width, area, perimeter, lateral asymmetry, inner angles and shape index. Results: Geographic differences several variables of leaves in R. mangle and A. germinans were detected, but L. racemosa showed high similarity among localities. Differences can be explained by environmental differences in localities. Conclusions: There is a need for more extensive research on these kinds of foliar indicators to support it use in future monitoring or researches, and for that using digital pictures fotografías pose many advantages.

Endomeriosis of Cesarean Section Why on Leet side?

Background: Endometriosis is defined as the presence or growth of ectopic endometrial tissue outside their usual site ( the uterus). It is a common condition in women. It may occur in the ovaries, fallopian tubes, vagina and rarely, endometriosis may occur in the abdomen and lungs. Endometriosis is common among women of reproductive age. It is either primary or secondary. The triad of diagnosis is a pain with menstruation, cesarean scar and a mass in the scar. Methods: A report a series of 65 patients in the period from 1st Jan 2013 to 31st Dec 2017. The study was performed in Al-Kindi Teaching Hospital and a private hospital. The mean age was 35 years (range 20-45).All patients were treated surgically i.e. excision of the tumor and old surgical scar in the lower abdomen. Result: mean age was 35 years (range 20-45). Thirty patients (46.15%) were housewives while 35(53.84%) were officers. The interesting finding is that 52 patients had the mass in the left side, 10 in the middle and only 3 in the right side of the scar respectively. Conclusion: Our study demonstrated a lateral asymmetry in the location of scar endometriosis i.e. mostly on the left side. The prevalence on left side of scar can be added to the triad of diagnosis mentioned above I.e. cyclical pain, cesarean scar and mass mostly in left side of the scar.