Stroke Subjects Research Articles

Ultrasound assessment of muscle and fascia properties and the effects of spasticity and botulinum toxin injections on spastic muscles in chronic stroke survivors

Abstract Objective To objectively quantify changes in muscle properties in chronic stroke survivors and the effects of spasticity and botulinum toxin injections (BoNTi) on muscle properties using ultrasonography. Design In this cross-sectional observational study, 24 stroke subjects with history of BoNTi to biceps brachii muscles (BB) but without BoNTi to the triceps (TRI) were included. Results 12 subjects had spastic TRI, the other half did not. 20 subjects had spasticity in wrist flexors, and 11 subjects received BoNTi to the flexor carpii ulnaris (FCU). On average, a significant decrease in muscle thickness (16.5% loss in TRI), a thicker fascia with higher echo intensity were noted on muscles in the paretic limb. Percent muscle loss (PML) was significantly less (11.0%) in spastic TRI than in non-spastic TRI (22.1%). There was no statistically significant difference in muscle and fascia properties in spastic FCU with and without BoNTi. Spasticity did not correlate significantly with muscle loss, fascia thickness or echo intensity. Conclusion Our results provided evidence that muscles on the spastic-paretic side had less muscle mass, thicker fascia and greater echo intensity. Our results showed that spasticity helped maintain muscle mass, but failed to reveal additional muscle loss after botulinum toxin injection.

Corticospinal and corticoreticulospinal projections have discrete but complementary roles in chronic motor behaviors after stroke.

After corticospinal tract (CST) stroke, several motor deficits can emerge in the upper extremity (UE), including diminished muscle strength, motor control, and muscle individuation. Both the ipsilesional CST and contralesional corticoreticulospinal tract (CReST) innervate the paretic UE, but their relationship to motor behaviors after stroke remains uncertain. In this cross-sectional study of 15 chronic stroke and 28 healthy subjects, we examined two questions: whether the ipsilesional CST and contralesional CReST differentially relate to chronic motor behaviors in the paretic arm and hand, and whether the severity of motor deficits differ by proximal versus distal location. In the paretic biceps and first dorsal interosseous muscles, we therefore used transcranial magnetic stimulation to measure the projection strengths of the ipsilesional CST and contralesional CReST. We also used quantitative testing to measure strength, motor control, and muscle individuation in each muscle. Stroke subjects had comparable muscle strength to healthy subjects but poorer motor control and muscle individuation. In both muscles, stronger ipsilesional CST projections related to better motor control, whereas stronger contralesional CReST projections related to better muscle strength. Stronger CST projections related to better individuation in the biceps alone. The severity of motor control and individuation deficits was comparable in the arm and hand. These findings suggest that the ipsilesional CST and contralesional CReST have specialized but complementary roles in motor behaviors of the paretic arm and hand. They also suggest that deficits in motor control or muscle individuation are not segmentally biased, underscoring the functional reach and efficacy of the pathways.

Elevated risk of end-stage kidney disease in stroke patients: A population-based observational study.

Estimating the incidence of end-stage kidney disease (ESKD) in stroke survivors is important to assess and predict clinical course, improve post-stroke quality of life, and ultimately reduce health burden. Our objective was to assess the risk of ESKD in patients compared to a matched stroke-free control cohort. A nationwide retrospective cohort study was conducted in 315,326 stroke subjects and 390,781 matched stroke-free control subjects. Health examination results and claims data were collected from the Korean National Health Insurance Service during 2010-2018. Cox proportional hazard models were used to assess the risk of ESKD in the stroke cohort. During a mean follow-up period of 4.3 years, the incidence of ESKD was 1.83 per 100,000 person-years in the stroke cohort versus 0.57 per 100,000 person-years in the control cohort. The stroke cohort exhibited a significantly higher risk of developing ESKD compared to the matched control, with an adjusted hazard ratio (aHR) of 1.79 (95% confidence interval (CI) = 1.67-1.93). Stroke survivors were associated with a higher risk of developing ESKD, regardless of the severity of disability (aHRs of 1.93, 95% CI = 1.69-2.21 for severe disability; 1.71, 95% CI = 1.41-2.07 for mild disability; and 1.78, 95% CI = 1.65-1.92 for no disability), compared to the matching control cohort. The elevated risk was observed in both hemorrhagic stroke (aHR = 1.96, 95% CI = 1.73-2.23) and ischemic stroke (aHR = 1.75, 95% CI = 1.62-1.89). This study demonstrates that stroke patients have a significantly higher risk of incident ESKD. This highlights the need for heightened clinical awareness and improved monitoring of kidney function in this population.

The association between triglyceride-glucose index combined with obesity indicators and stroke risk: A longitudinal study based on CHARLS data

Background and objectiveThe triglyceride-glucose (TyG) index, a surrogate marker for insulin resistance, has been proposed as a predictor of cardiovascular events. However, the combined impact of the TyG index and obesity indicators, such as body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), on stroke risk was not fully understood. This study aimed to investigate the association between the TyG index combined with these obesity indicators and stroke risk in the Chinese population.Materials and methodsData on 17,708 participants aged 45 years or older for this study were collected from the China Health and Retirement Longitudinal Study (CHARLS) from baseline (2011) to the Wave 5 follow-up (2020). Cox proportional hazards model, restricted cubic spline (RCS) and receiver operating characteristic (ROC) analysis were employed to examine the association between the TyG index and its combined obesity-related indicators with stroke. Mediation analysis was conducted to explore the mutual potential mediating role of TyG and obesity indicators in the above relationships.ResultsA total of 8,207 participants with an average age of 58.2 years were investigated, of which 11.0% were stroke individuals, 44.80% were men and 84.6% were from rural areas. TyG, TyG-BMI, TyG-WHtR, TyG-WC were significantly higher in stroke subjects than in the non-stroke subjects (P < 0.001), and were significantly and positively associated with stroke in all 3 models (P < 0.05). Restricted cubic spline models revealed nonlinear associations between TyG and TyG-BMI with stroke (P-overall < 0.001, P-nonlinear = 0.003 for TyG, and P-overall < 0.001, P-nonlinear = 0.028 for TyG-BMI), while TyG-WC and TyG-WHtR (P-overall < 0.001 and P-nonlinear > 0.05) demonstrated linear associations with stroke after adjusting for covariates. TyG-WHtR, TyG-BMI and TyG-WC had more robust predictive power than TyG for risk of stroke. TyG-WHtR or TyG-WC had the highest predictive power for stroke (AUC:0.696, 95% CI 0.677–0.715), slightly higher than the other indicators. Associations between TyG, TyG-WC, TyG-WHtR, and TyG-BMI with stroke were found to be stronger among individuals who were ≥ 55 years of age, male. The relationship between TyG and stroke was significantly mediated by BMI, WHtR and WC (15.79%, 21.72%, and 24.06% respectively), while the relationship between these obesity measures and stroke was significantly mediated by TyG (18.48%, 14.45%, and 14.70% respectively).ConclusionThe combination of TyG and obesity-related indicators was significantly associated with stroke risk, and could improve predictive power for stroke compared to the single TyG. Obesity indicators and TyG mediated each other in their respective associations with stroke risk.

Transcranial Direct Current Stimulation for Improving Balance in Healthy Older Adults and Older Adults with Stroke: A Scoping Review.

Background/Objectives: Age-related decline in balance and postural control is common in healthy elders and is escalated in aging adults with stroke. Transcranial direct current stimulation (tDCS) has emerged as one of the promising brain stimulations adjoining therapeutic exercise to enhance the recovery of balance and motor functions in persons with and without neurological disorders. This review aims to summarize and compare the available evidence of the tDCS on improving balance in the older adults without neurological disorders and the older adults with stroke. Methods: The Ovid (Medline) database was searched from its inception through to 06/15/2024 for randomized controlled trials investigating tDCS for improving balance in older adults with and without stroke. Results: Overall, 20 appropriate studies (including 271 stroke subjects and 259 healthy older adults) were found. The data indicate mixed results of tDCS for improving balance in older adults with and without stroke. Conclusions: Based on current research evidence, we have not found a specific tDCS protocol that is more effective than other tDCS protocols for improving balance and postural control in healthy older adults and older adults with stroke. Further research should explore the ideal tDCS approach, possibly in conjunction with standard interventions, to optimize postural control and balance in healthy older adults and older adults with stroke.

Effect of intravenous thrombolysis with butylphthalide, edaravone and recombinant tissue plasminogen activator (rt-PA) on serum inflammatory factors in patients with ischemic stroke

Purpose: To study the impact of edaravone in combination with edaravone and recombinant tissue plasminogen activator (rt-PA) intravenous thrombolysis on serum inflammatory factors in ischemic stroke subjects. Methods: Eighty ischemic stroke patients in the First Affiliated Hospital of Xi'an Medical University, Xi’an, China were randomly assigned to study and control cohorts, each with 40 subjects. Patients in control cohort were administered edaravone and rt-PA intravenous thrombolysis. The study cohort received butylphthalide in combination with edaravone and rt-PA intravenous thrombolysis. Treatment effectiveness/efficacy, neurological function, self-care ability, inflammatory indicator levels, and blood cell levels were compared between the 2 cohorts. Results: Efficacy was significantly better in the study cohort than in the control cohort (p &lt; 0.05). After treatment, NIHSS score was significantly lower in the study cohort than in control cohort, while ADL score was significantly higher in the study cohort (p &lt; 0.05). After medication, CRP level was decreased significantly in both cohorts, but was significantly lower level in the study cohort (p &lt; 0.05). Treatment led to significant reductions in white blood cell count, neutrophil count, and NLR ratio in the study cohort, relative to the control cohort (p &lt; 0.05). Conclusion: The use of butylphthalide in combination with edaravone and rt-PA intravenous thrombolysis produces significant and beneficial effects on ischemic stroke subjects by regulating abnormal levels of inflammatory cells, improving coagulation status and decreasing inflammation. Moreover, it ameliorates neurological defects and improves activities of daily living. There is, however, a need to determine the mechanisms of action of this combination therapy and the influence of other cofounding factors on the activities of the combination therapy.

Differences in Trunk Acceleration-Derived Gait Indexes in Stroke Subjects with and without Stroke-Induced Immunosuppression.

Background: Stroke-induced immunosuppression (SII) represents a negative rehabilitative prognostic factor associated with poor motor performance at discharge from a neurorehabilitation unit (NRB). This study aims to evaluate the association between SII and gait impairment at NRB admission. Methods: Forty-six stroke patients (65.4 ± 15.8 years, 28 males) and 42 healthy subjects (HS), matched for age, sex, and gait speed, underwent gait analysis using an inertial measurement unit at the lumbar level. Stroke patients were divided into two groups: (i) the SII group was defined using a neutrophil-to-lymphocyte ratio ≥ 5, and (ii) the immunocompetent (IC) group. Harmonic ratio (HR) and short-term largest Lyapunov's exponent (sLLE) were calculated as measures of gait symmetry and stability, respectively. Results: Out of 46 patients, 14 (30.4%) had SII. HR was higher in HS when compared to SII and IC groups (p < 0.01). HR values were lower in SII when compared to IC subjects (p < 0.01). sLLE was lower in HS when compared to SII and IC groups in the vertical and medio-lateral planes (p ≤ 0.01 for all comparisons). sLLE in the medio-lateral plane was higher in SII when compared to IC subjects (p = 0.04). Conclusions: SII individuals are characterized by a pronounced asymmetric gait and a more impaired dynamic gait stability. Our findings underline the importance of devising tailored rehabilitation programs in patients with SII. Further studies are needed to assess the long-term outcomes and the role of other clinical features on gait pattern.

Early screening of post-stroke fall risk: A simultaneous multimodal fNIRs-EMG study.

Stroke is the third-leading cause of death and disability, and poststroke falls (PSF) are common at all stages after stroke and could even lead to injuries or death. Brain information from functional near-infrared spectroscopy (fNIRs) may precede conventional imaging and clinical symptoms but has not been systematically considered in PSF risk prediction. This study investigated the difference in brain activation between stroke patients and healthy subjects, and this study was aimed to explore fNIRs biomarkers for early screening of PSF risk by comparing the brain activation in patients at and not at PSF risk. In this study, we explored the differences in brain activation and connectivity between stroke and healthy subjects by synchronizing the detection of fNIRs and EMG tests during simple (usual sit-to-stand) and difficult tasks (sit-to-stand based on EMG feedback). Thereby further screened for neuroimaging biomarkers for early prediction of PSF risk by comparing brain activation variability in poststroke patients at and not at fall risk during simple and difficult tasks. The area under the ROC curve (AUROC), sensitivity, and specificity were used to compare the diagnostic effect. A total of 40 patients (22 not at and 18 at PSF risk) and 38 healthy subjects were enrolled. As the difficulty of standing task increased, stroke patients compared with healthy subjects further increased the activation of the unaffected side of supplementary motor area (H-SMA) and dorsolateral prefrontal cortex-Brodmann area 46 (H-DLFC-BA46) but were unable to increase functional connectivity (Group*Task: p < 0.05). More importantly, the novel finding showed that hyperactivation of the H-SMA during a simple standing task was a valid fNIRs predictor of PSF risk [AUROC 0.74, p = 0.010, sensitivity 77.8%, specificity 63.6%]. This study provided novel evidence that fNIR-derived biomarkers could early predict PSF risk that can facilitate the widespread use of real-time assessment tools in early screening and rehabilitation. Meanwhile, this study demonstrated that the higher brain activation and inability to increase the brain functional connectivity in stroke patients during difficult task indicated the inefficient use of brain resources.

Changes in nutritional status, risk factors and food intake in stroke subjects: cohort study analysis of non-communicable disease risk factors

Background: Stroke is a major cause of death and disability worldwide, affecting 15 million people annually. In Indonesia, the prevalence is 10.9%. Major risk factors include high blood pressure, obesity, inactivity, poor diet, and smoking. Objective: This study aims to analyze long-term trends in risk factors, nutritional status, and food intake among stroke patients from 2011-2021, assessing their impact on stroke incidence. Methods: Data from a longitudinal cohort study of 5,329 subjects, including 215 stroke patients, were analyzed using Microsoft Excel 2019 and SAS software. ANOVA was used to assess annual changes in risk factors, nutritional status, and food intake. Survival analysis was conducted with SAS PROC LIFETEST and PROC LIFEREG. Results: The cohort was primarily female (62.8%), aged 60 or older (57.2%), senior high school education (25.6%), civil servants (30.7%), and low income (57.2%). Significant changes were noted in BMI (p=0.037), fasting blood glucose (FBG) (p=0.001), HDL (p=0.049), abdominal circumference, smoking habits, physical activity (p&lt;0.001), protein intake (p=0.026), and intake of energy, fat, carbohydrates, and sodium (p&lt;0.001). Factors significantly associated with stroke included age, FBG, postprandial glucose, smoking (p&lt;0.0001), LDL (p=0.0380), HDL (p=0.0126), physical activity (p=0.0455), energy intake (p=0.0002), fat intake (p=0.0007), and sodium intake (p=0.0012). Conclusions: The study highlights significant changes in nutritional status, glucose levels, HDL cholesterol, physical activity, and smoking habits. These factors, along with age, cholesterol levels, and dietary intake, impact stroke incidence, underscoring the need for comprehensive stroke prevention strategies.

Concurrent tDCS-fMRI after stroke reveals link between attention network organization and motor improvement

Restoring motor function after stroke necessitates involvement of numerous cognitive systems. However, the impact of damage to motor and cognitive network organization on recovery is not well understood. To discover correlates of successful recovery, we explored imaging characteristics in chronic stroke subjects by combining noninvasive brain stimulation and fMRI. Twenty stroke survivors (6 months or more after stroke) were randomly assigned to a single session of transcranial direct current stimulation (tDCS) or sham during image acquisition. Twenty healthy subjects were included as controls. tDCS was limited to 10 min at 2 mA to serve as a mode of network modulation rather than therapeutic delivery. Fugl-Meyer Assessments (FMA) revealed significant motor improvement in the chronic stroke group receiving active stimulation (p = 0.0005). Motor changes in this group were correlated in a data-driven fashion with imaging features, including functional connectivity (FC), surface-based morphometry, electric field modeling and network topology, focusing on relevant regions of interest. We observed stimulation-related changes in FC in supplementary motor (p = 0.0029), inferior frontal gyrus (p = 0.0058), and temporo-occipital (p = 0.0095) areas, though these were not directly related to motor improvement. The feature most strongly associated with FMA improvement in the chronic stroke cohort was graph topology of the dorsal attention network (DAN), one of the regions surveyed and one with direct connections to each of the areas with FC changes. Chronic stroke subjects with a greater degree of motor improvement had lower signal transmission cost through the DAN (p = 0.029). While the study was limited by a small stroke cohort with moderate severity and variable lesion location, these results nevertheless suggest a top-down role for higher order areas such as attention in helping to orchestrate the stroke recovery process.

The differential proteomic response to ischemic stroke in appalachian subjects treated with mechanical thrombectomy

IntroductionThe Appalachia region of North America is known to have significant health disparities, specifically, worse risk factors and outcomes for stroke. Appalachians are more likely to have comorbidities related to stroke, such as diabetes, obesity, and tobacco use, and are often less likely to have stroke interventions, such as mechanical thrombectomy (MT), for emergent large vessel occlusion (ELVO). As our Comprehensive Stroke Center directly serves stroke subjects from both Appalachian and non-Appalachian areas, inflammatory proteomic biomarkers were identified associated with stroke outcomes specific to subjects residing in Appalachia.MethodsThere were 81 subjects that met inclusion criteria for this study. These subjects underwent MT for ELVO, and carotid arterial blood samples acquired at time of intervention were sent for proteomic analysis. Samples were processed in accordance with the Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC; clinicaltrials.gov; NCT 03153683). Statistical analyses were utilized to examine whether relationships between protein expression and outcomes differed by Appalachian status for functional (NIH Stroke Scale; NIHSS and Modified Rankin Score; mRS), and cognitive outcomes (Montreal Cognitive Assessment; MoCA).ResultsNo significant differences were found in demographic data or co-morbidities when comparing Appalachian to non-Appalachian subjects. However, time from stroke onset to treatment (last known normal) was significantly longer and edema volume significantly higher in patients from Appalachia. Further, when comparing Appalachian to non-Appalachian subjects, there were significant unadjusted differences in the NIHSS functional outcome. A comprehensive analysis of 184 proteins from Olink proteomic (92 Cardiometabolic and 92 Inflammation panels) showed that the association between protein expression outcomes significantly differed by Appalachian status for seven proteins for the NIHSS, two proteins for the MoCA, and three for the mRS.ConclusionOur study utilizes an ELVO tissue bank and registry to investigate the intracranial/intravascular proteomic environment occurring at the time of thrombectomy. We found that patients presenting from Appalachian areas have different levels of proteomic expression at the time of MT when compared to patients presenting from non-Appalachian areas. These proteins differentially relate to stroke outcome and could be used as prognostic biomarkers, or as targets for novel therapies. The identification of a disparate proteomic response in Appalachian patients provides initial insight to the biological basis for health disparity. Nevertheless, further investigations through community-based studies are imperative to elucidate the underlying causes of this differential response.

Altered brain function during movement programming is linked with motor deficits after stroke: a high temporal resolution study.

Stroke leads to motor deficits, requiring rehabilitation therapy that targets mechanisms underlying movement generation. Cortical activity during the planning and execution of motor tasks can be studied using EEG, particularly via the Event Related Desynchronization (ERD). ERD is altered by stroke in a manner that varies with extent of motor deficits. Despite this consensus in the literature, defining precisely the temporality of these alterations during movement preparation and performance may be helpful to better understand motor system pathophysiology and might also inform development of novel therapies that benefit from temporal resolution. Patients with chronic hemiparetic post-stroke (n = 27; age 59 ± 14 years) and age-matched healthy right-handed control subjects (n = 23; 59 ± 12 years) were included. They performed a shoulder rotation task following the onset of a stimulus. Cortical activity was recorded using a 256-electrode EEG cap. ERD was calculated in the beta frequency band (15-30 Hz) in ipsilesional sensorimotor cortex, contralateral to movement. The ERD was compared over time between stroke and control subjects using permutation tests. The correlation between upper extremity motor deficits (assessed by the Fugl-Meyer scale) and ERD over time was studied in stroke patients using Spearman and permutation tests. Patients with stroke showed on average less beta ERD amplitude than control subjects in the time window of -350 to 50 ms relative to movement onset (t(46) = 2.8, p = 0.007, Cohen's d = 0.31, 95% CI [0.22: 1.40]). Beta-ERD values correlated negatively with the Fugl-Meyer score during the time window -200 to 400 ms relative to movement onset (Spearman's r = -0.54, p = 0.003, 95% CI [-0.77 to -0.18]). Our results provide new insights into the precise temporal changes of ERD after hemiparetic stroke and the associations they have with motor deficits. After stroke, the average amplitude of cortical activity is reduced as compared to age-matched controls, and the extent of this decrease is correlated with the severity of motor deficits; both were true during motor programming and during motor performance. Understanding how stroke affects the temporal dynamics of cortical preparation and execution of movement paves the way for more precise restorative therapies. Studying the temporal dynamics of the EEG also strengthens the promising interest of ERD as a biomarker of post-stroke motor function.

An Investigative Study of Prothrombin Time, Activated Partial Thromboplastin Time and Antithrombin Levels in Patients with Ischaemic Stroke

Background: The haemostatic system maintains a balance between prothrombotic and antithrombotic components in the body. The role of this system in ischaemic stroke is not certain. Objective: Prothrombin time (PT) and Activated Partial Thromboplastin Time(APTT) are widely used screening tests to assess the haemostatic cascade. We sought to evaluate the relevance of these test and antithrombin (AT) levels in patients with ischaemic stroke. Methods: AT, platelet count, PT and APTT tests were carried out for 65 patients with ischaemic stroke and 65 controls with no history of stroke. Results: The mean age of stroke subjects was 60.4 ± 12.3yrs. PT and APTT in the test and control groups were similar and Antithrombin levels did not show significant difference. But there was a significant association between functional AT deficiency and diabetes mellitus in the ischaemic stroke group. A significant negative correlation existed between functional AT activity and prothrombin and between AT Ag levels and APTT Conclusion: There was no difference in the Antithrombin levels, PT and APTT values in patients with ischaemic stroke and those without a history of stroke and carrying out these tests routinely to assess hypercoagulable states in ischaemic stroke patients may not have any diagnostic value in our population.

Efficacy of a Four-Week Diagonal Pattern Exercise Program on Trunk and Lower Limb Function in Patients With Stroke-Induced Hemiplegia.

Objective The intended effect of this investigation is to quantifythe efficacy of a four-week program of diagonal pattern exercises in managing trunk impairments and improving gait difficulties in hemiplegic stroke subjects. The study aims to measure changes in trunk stability and gait parameters post-intervention, providing insights into the potential therapeutic benefits of these exercises for stroke rehabilitation. Methodology Thisexperimentation approach encompassing before and the follow-up test evaluations was implemented in this investigation. It was conducted at Madha College of Physiotherapy, Chennai, using convenience sampling to recruit 20 stroke subjects meeting specific inclusion criteria. Participants underwent pre-test evaluations for trunk control and gait. They were then divided equally into two groups for a four-week intervention comprising diagonal pattern exercises or single-plane training. Treatment sessions were administered five days per week for 45 minutes each. Posttest evaluations assessed changes in trunk control using the Trunk Impairment Scale (TIS) and gait parameters via the Timed Up and Go (TUG) test. Results Pretest analysis indicated no substantial baseline variations amongthe experimental and control groups, affirming their suitability for comparison. Posttest analysis of intervention at a 5% significance level revealed that the experimental group demonstrated a statistically significant improvement in trunk control, as measured by the TIS and TUG test, compared to the control group. The paired t-testresults showed significant differences in pre- and posttest values within each group, while the unpaired t-test confirmed the superiority of the experimental group's outcomes, with a P-value < 0.05. This improvement is likely due to the effectiveness of the diagonal pattern exercise in enhancing trunk muscle activity and coordination. Conclusions This study concludes that diagonal pattern training is more beneficial for improving trunk musculature control and locomotory ability in chronic cerebrovascular accident subjects. The exercise program's simplicity, minimal risks, and ease of home application after initial therapist supervision make it a promising therapeutic approach.

Identifying alterations in hand movement coordination from chronic stroke survivors using a wearable high-density EMG sleeve

Objective.Non-invasive, high-density electromyography (HD-EMG) has emerged as a useful tool to collect a range of neurophysiological motor information. Recent studies have demonstrated changes in EMG features that occur after stroke, which correlate with functional ability, highlighting their potential use as biomarkers. However, previous studies have largely explored these EMG features in isolation with individual electrodes to assess gross movements, limiting their potential clinical utility. This study aims to predict hand function of stroke survivors by combining interpretable features extracted from a wearable HD-EMG forearm sleeve.Approach.Here, able-bodied (N= 7) and chronic stroke subjects (N= 7) performed 12 functional hand and wrist movements while HD-EMG was recorded using a wearable sleeve. A variety of HD-EMG features, or views, were decomposed to assess alterations in motor coordination.Main Results.Stroke subjects, on average, had higher co-contraction and reduced muscle coupling when attempting to open their hand and actuate their thumb. Additionally, muscle synergies decomposed in the stroke population were relatively preserved, with a large spatial overlap in composition of matched synergies. Alterations in synergy composition demonstrated reduced coupling between digit extensors and muscles that actuate the thumb, as well as an increase in flexor activity in the stroke group. Average synergy activations during movements revealed differences in coordination, highlighting overactivation of antagonist muscles and compensatory strategies. When combining co-contraction and muscle synergy features, the first principal component was strongly correlated with upper-extremity Fugl Meyer hand sub-score of stroke participants (R2= 0.86). Principal component embeddings of individual features revealed interpretable measures of motor coordination and muscle coupling alterations.Significance.These results demonstrate the feasibility of predicting motor function through features decomposed from a wearable HD-EMG sleeve, which could be leveraged to improve stroke research and clinical care.

Unveiling Opportunities for Intervention: A Prospective Cohort Study Investigating the Clinical Significance of Diffusion-Weighted Imaging (DWI)-Fluid-Attenuated Inversion Recovery (FLAIR) Mismatch Beyond the Window Period in Acute Ischemic Stroke.

Acute ischemic stroke causes irreversible damage to the brain parenchymasurrounded by salvageable tissue known as the ischemic penumbra.Magnetic resonance imaging (MRI), particularly the mismatch between abnormal diffusion-weighted imaging (DWI) signals and normal fluid-attenuated inversion recovery (FLAIR) signals, plays a critical role in detecting ischemic penumbra. It also allows for the identification of patients who may benefit from reperfusion therapy. Hence, this prospective cohort study aimed to explore the correlation between DWI-FLAIR mismatch and clinical outcomes in acute ischemic stroke patients, specifically those with delayed or uncertain symptom onset, offering potential insights into reperfusion therapy. A total of 38 thrombotic stroke patients aged above 18 were included in this prospective cohort study. Baseline data, including demographics, lifestyle factors, and medical history, were recorded. DWI-FLAIR mismatch was evaluated through brain MRI within 4.5 hours to 12 hours of symptom onset. Of the cohort, 63.2% were males, predominantly in the 61-70 age group. Smoking and alcohol consumption were reported by 15.79% each. DWI-FLAIR mismatch was present in 20 out of 38 subjects. No statistically significant differences were noted in the mean National Institutes of Health Stroke Scale (NIHSS) and Modified Rankin Scale (MRS) scores between subjects with and without DWI-FLAIR mismatch. Thrombolysis in wake-up stroke subjects demonstrated a substantial reduction in mean MRS at discharge (1.29±0.95) and at six to eight weeks (1.71±1.11), suggesting potential benefits on functional outcomes. The prevalence of DWI-FLAIR mismatch was seen in the majority of patients beyond their window period and also showed beneficiary outcomes with a mean reduction in NHISS and MRS scores following thrombolysis.

The Use of Virtual Reality in Stable Sitting Trunk Rehabilitation for Stroke Patients: A Pilot Study

INTRODUCTION: Virtual reality (VR) holds promise for stroke rehabilitation. However, many existing VR systems requires users to stand while playing, posing a potential falling risk for stroke patients. This study investigated the effects of a custom-developed VR system that focus on trunk rehabilitation in stable sitting position on muscle activities, postural control, and physiological cost compared to conventional trunk exercises in stroke patients. MATERIALS AND METHODS: A cross-sectional observational pilot study was conducted involving 12 paretic stroke subjects performing four exercises: two Conventional Trunk Exercises (CTE) and two VR-based Trunk Exercises (VRTE) using customized Tilt-The-Maze (self-paced) or Catch-The-Mole (game-paced) games. Muscle activity was measured using electromyography (EMG). Postural control data in the Anterior-Posterior (AP) and Medio-Lateral (ML) axes was recorded using a force plate, while the physiological cost was measured via a heart rate sensor during the exercises. RESULTS: The results indicated low muscle activity and light-intensity cardiovascular responses in all CTE and VRTE exercises. Game-paced VRTE recorded slightly higher Center of Pressure (CoP) velocity in the AP and ML axes versus CTE (AP:4.40±1.80 vs. 4.02±1.20 cm/s; ML:6.40±2.54 vs. 5.42±2.21 cm/s). In contrast, the self-paced VRTE showed an insignificant impact on postural control than both CTE and game-paced VRTE. CONCLUSION: The game-paced VRTE induced comparable effects on muscular activation, postural control, and physiological cost to that of CTE in stroke patients. The findings suggest the stable-sitting VR system as a supplementary approach to the existing trunk rehabilitation protocols for stroke patients.

General and Specific Quality of Life Course of Individuals with Different Levels of Stroke Severity: A One-Year Prospective Longitudinal Study

ABSTRACT Objectives To compare the course of generic and specific health-related quality of life (HRQOL) of individuals with stroke, and its physical, mental, and social domains, at three, six, and 12 months after hospital discharge, considering the levels of stroke severity. Methods This is a longitudinal study, in stroke individuals, assessed during hospital admission by the National Institutes of Health Stroke Scale (NIHSS), and divided into mild (NIHSS ≤3) or moderate/severe (NIHSS ≥4) disease. At three, six, and 12 months after hospital discharge, the individuals were assessed for generic (Short Form Health Survey–36: total score and physical and mental domains) and specific (Stroke Specific Quality of Life Scale: total score and social domain) HRQOL. A 2 × 2 repeated measures analysis of variance (ANOVA) with post-hoc was applied. Results 146, 122, and 103 individuals were assessed at three, six and 12 months, respectively HRQOL courses showed different behaviors according to stroke severity (3.37≤F ≤ 4.62; 0.010≤p ≤ .036). Individuals with mild stroke showed significant changes in the physical domain, with a reduction between three and six months, and an increase between six and 12. Moderate/severe individuals showed a significant increase in all HRQOL variables between three and six months, and a maintenance of values for almost all variables, except for physical domain, which improved significantly between three and six months, and got significantly worse between six and 12. Conclusions HRQOL during the first year after stroke showed distinct trajectories, being stroke severity an important factor in identifying stroke subjects at risk of HRQOL decline. Clinical Implications These results demonstrate the importance of considering not only the phase of the stroke, the severity, and the general and specific HRQOL, but also the physical, social, and mainly the mental domain, which has long been neglected, when assessing this population.

The dynamics of oligodendrocyte populations following permanent ischemia promotes long-term spontaneous remyelination of damaged area

Stroke is a major public health concern, with limited clinically approved interventions available to enhance sensorimotor recovery beyond reperfusion. Remarkably, spontaneous recovery is observed in certain stroke patients, suggesting the existence of a brain self-repair mechanism not yet fully understood. In a rat model of permanent cerebral ischemia, we described an increase in oligodendrocytes expressing 3RTau in damaged area. Considering that restoration of myelin integrity ameliorates symptoms in many neurodegenerative diseases, here we hypothesize that this cellular response could trigger remyelination. Our results revealed after ischemia an early recruitment of OPCs to damaged area, followed by their differentiation into 3RTau+ pre-myelinating cells and subsequent into remyelinating oligodendrocytes. Using rat brain slices and mouse primary culture we confirmed the presence of 3RTau in pre-myelinating and a subset of mature oligodendrocytes. The myelin status analysis confirmed long-term remyelination in the damaged area. Postmortem samples from stroke subjects showed a reduction in oligodendrocytes, 3RTau+ cells, and myelin complexity in subcortical white matter. In conclusion, the dynamics of oligodendrocyte populations after ischemia reveals a spontaneous brain self-repair mechanism which restores the functionality of neuronal circuits long-term by remyelination of damaged area. This is evidenced by the improvement of sensorimotor functions in ischemic rats. A deep understanding of this mechanism could be valuable in the search for alternative oligodendrocyte-based, therapeutic interventions to reduce the effects of stroke.

Muscle synergies and muscle networks in multiple frequency components in post-stroke patients

As a neural control strategy employed by the central nervous system to control movements, the extraction of muscle synergies from a broad range of electromyographic signals has been the focus. Nevertheless, recent coherence analysis demonstrates distinct roles played in low-frequency components in motor control. This suggests that muscle synergies extracted from the low-frequency components can capture movement characteristics as done in the full-band. To investigate this issue, muscle synergies were extracted from three distinct frequency components (20–450 Hz, 20–30 Hz, 30–450 Hz) during spatial reaching movements in a group of healthy and stroke subjects. Synergy similarities were computed both within frequencies and between groups, and complex network analysis was conducted based on the group-averaged synergies. Results showed that the number and structure of muscle synergies, as well as network metrics, identified from the full-band (20–450 Hz) and low-frequency (20–30 Hz) exhibited high similarity between groups. These patterns diverged from those observed in high-frequency (30–450 Hz). The stroke did not induce significant alterations in muscle synergies. However, higher network metrics were identified in the full-band for one synergy. This study demonstrated the capacity of low-frequency components to perform muscle synergy analysis. These findings can help better understand the neural drive and motor control, potentially advancing the assessment of motor function and rehabilitation strategies.