Chronic Stroke Research Articles

Group Task-Specific Training for Stroke Survivors

Abstract Date Presented 03/22/24 A group task-specific training (TST) program for chronic stroke survivors elicited positive motor and quality-of-life outcomes, which highlights the feasibility of providing an optimal dosage of TST using group training to improve overall function. Primary Author and Speaker: Taylor Drost Contributing Authors: Rose Tilton, Christine O’Neill, Samuel T. Nemanich

A Reliability Study of the Load Distribution Percentage While Walking Using Curalgia Feet Sx Smart Insoles.

Background Gait analysis has evolved through many years of research. Many methods are used to analyze the gait of a subject. Recent times have showna high demand for wearable sensor-based insoles integrated with smartphone-based devices used for gait analysis due to ease of use. This study utilized Curalgia Feet Sx Smart Insoles and its software toolset, Gait Analysis+, designed and manufactured in India making it an accessible and cost-effective option. The Curalgia Feet Sx Smart Insoles allow for a broad range of biofeedback-based rehabilitation and recovery training for several patients and have many applications, such as sports performance enhancement and neurological disorder rehab (e.g., brain stroke rehab). The system also significantly delays the onset of neurodegenerative illnesses by providing balance and proprioceptive training. The smart insole can help the athlete, the coach, and the sports medicine team get the on-field data in real-time, which will help them understand if any technical or biomechanical alterations are required. This may help in performance enhancement. This study aimed to determine the interrater reliability of the load distribution percentage parameter of the Curalgia Feet Sx Smart Insole for both feet while walking in a controlled setting. Methodology A total of 120 subjects were enrolled in the study. In total, 90 subjects were randomly selected using Research Randomizer which included male and female students and staff at Sardar Bhagwan Singh University. The subjects were asked to come to the research lab of the physiotherapy department wearing their sports shoes. Curalgia Feet Sx insoles were inserted into the shoe firmly to fit properly. Two assessors took two readings after the smart insole was connected to the smartphone-based application, GaitAnalysis+, via Bluetooth. The dynamic analysis option was selected, and each subject's analysis was done one after another with a desirable break in between. Each subject walked for three minutes at their normal speed after pressing "Start Analysis." At the three-minute mark, the subjects were asked to press "Stop Analysis" and the investigator downloaded the report on the smartphone. The data collected was compiled as the cumulative weight in kg (load distribution) borne and the % weight (load distribution %) borneby each foot for the duration of the walk. Statistical analysis was done using Karl Pearson's test and interclass correlation calculation. Results Assessor 1 and Assessor 2 collected readings for the left foot as "L" and the right foot as "R." Assessor 1 readings were L1-R1 for load distribution and L1% and R1% for load distribution %. Assessor 2 readings were L2-R2 for load distribution and L2% and R2% for load distribution %. The r value (correlation coefficient) was calculated using the load distribution. The mean value of L1 was 337.46 (SD=94.16). The mean L2 was 313.6 (SD=104.40). The R1 mean was 229.03 (SD=112.88), and the R2 mean was 233.011 (SD=79.84). The r was 0.7171 for the left foot and 0.7502 for the right foot, suggesting an excellent correlation. The ICC was calculated for load distribution %. The means of L1% was 55.94, L2% was 57.59, R1% was 44.06, and R2% was 42.41. The ICC was found to be 0.91 for both feet, suggesting high interrater reliability for the tested parameter. Conclusions The findings confirmed that the Curalgia Feet Sx Smart Insoles presented good interrater reliability for the load distribution % parameter.

Outcomes Among Mexican American and Non-Hispanic White Informal Stroke Caregivers.

Informal home care is prevalent among Mexican American stroke survivors, but data on the impact on caregivers are not available. The aim was to assess ethnic differences in informal stroke caregiving and caregiver outcomes at 90 days poststroke. Informal caregivers were recruited from the population-based Brain Attack Surveillance in Corpus Christi Project (2019-2023), conducted in a bi-ethnic community in Texas. Caregivers of community-dwelling stroke survivors who were not cognitively impaired and not employed by a formal caregiving agency were interviewed. Interviews included sociodemographics, dyad characteristics, Modified Caregiver Strain Index (range 0-26, higher more positive), Positive Aspects of Caregiving scale (range, 5-45, higher more), Patient Health Questionnaire-8 (range, 0-30, higher worse), and PROMIS (Patient-Reported Outcomes Measurement Information System)-10 physical (range, 16.2-67.7, higher better) and mental health (range, 21.2-67.6, higher better) summary scores. Stroke survivor data was from interviews and medical records. Propensity score methods were used to balance caregiver and patient factors among Mexican American and Non-Hispanic White caregivers by fitting a model with ethnicity of caregiver as the outcome and predictors being caregiver sociodemographics, patient-caregiver dyad characteristics, and patient sociodemographics and functional disability. Propensity scores were included as a covariate in regression models, considering the association between ethnicity and outcomes. Mexican American caregivers were younger, more likely female, and more likely a child of the stroke survivor than Non-Hispanic White caregivers. Mexican American caregiver ethnicity was associated with less caregiver strain (β, -1.87 [95% CI, -3.51 to -0.22]) and depressive symptoms (β, -2.02 [95% CI, -3.41 to -0.64]) and more favorable mental health (β, 4.90 [95% CI, 2.49-7.31]) and positive aspects of caregiving (β, 3.29 [95% CI, 1.35-5.23]) but not associated with physical health. Understanding the mechanisms behind more favorable caregiver outcomes in Mexican American people may aid in the design of culturally sensitive interventions to improve both caregiver and stroke survivor outcomes, potentially across all race and ethnic groups.

The Perspectives of Individuals with Chronic Stroke on Motor Recovery: A Qualitative Analysis.

The priorities of individuals with chronic stroke are not always reflected in clinical practice. This study provides insight into meaningful factors related to long-term motor recovery in stroke survivors. Thirty individuals with chronic stroke participated in semi-structured interviews about movement, recovery, and barriers to and facilitators of mobility and paretic arm use. The interviews were analyzed using inductive thematic analysis. Three categories, the individual, environment, and task, defined five emergent themes. Individual: (1) mindset is a strong and consistent influencer of daily physical activity and overall recovery; (2) severe physical impairment limits physical activity and recovery, regardless of other factors; and (3) a negative perception of disability impacts mindset and willingness to move in public. Environment: (4) social and physical environments influence physical activity and recovery. Task: (5) participation in meaningful activities increases physical activity and promotes long-term recovery. Strategies to incorporate paretic arm use, exercise, and encouragement from others facilitate physical activity. Insufficient paretic limb function, environmental obstacles, and fear are barriers to physical activity. Neurorehabilitation must address the factors that are meaningful to stroke survivors. Building motor capacity is essential and must be integrated with factors such as a positive mindset and proper environment. Individual differences reinforce the need for personalized care.

Safety & efficacy of a robotic hip exoskeleton on outpatient stroke rehabilitation

ObjectiveThe objective of this study was to analyze the safety and efficacy of using a robotic hip exoskeleton designed by Samsung Electronics Co., Ltd., Korea, called the Gait Enhancing and Motivating System-Hip (GEMS-H), in assistance mode only with the poststroke population in an outpatient-rehabilitation setting.MethodsForty-one participants with an average age of 60 and average stroke latency of 6.5 years completed this prospective, single arm, interventional, longitudinal study during the COVID-19 pandemic. Significant modifications to the traditional outpatient clinical environment were made to adhere to organizational physical distancing policies as well as guidelines from the Centers for Disease Control. All participants received gait training with the GEMS-H in assistance mode for 18 training sessions over the course of 6–8 weeks. Performance-based and self-reported clinical outcomes were assessed at four time points: baseline, midpoint (after 9 training sessions), post (after 18 training sessions), and 1-month follow up. Daily step count was also collected throughout the duration of the study using an ankle-worn actigraphy device. Additionally, corticomotor excitability was measured at baseline and post for 4 bilateral lower limb muscles using transcranial magnetic stimulation.ResultsBy the end of the training program, the primary outcome, walking speed, improved by 0.13 m/s (p < 0.001). Secondary outcomes of walking endurance, balance, and functional gait also improved as measured by the 6-Minute Walk Test (47 m, p < 0.001), Berg Balance Scale (2.93 points, p < 0.001), and Functional Gait Assessment (1.80 points, p < 0.001). Daily step count significantly improved with and average increase of 1,750 steps per day (p < 0.001). There was a 35% increase in detectable lower limb motor evoked potentials and a significant decrease in the active motor threshold in the medial gastrocnemius (-5.7, p < 0.05) after training with the device.ConclusionsGait training with the GEMS-H exoskeleton showed significant improvements in walking speed, walking endurance, and balance in persons with chronic stroke. Day-to-day activity also improved as evidenced by increased daily step count. Additionally, corticomotor excitability changes suggest that training with this device may help correct interhemispheric imbalance typically seen after stroke.Trial RegistrationThis study is registered with ClinicalTrials.gov (NCT04285060).

Bottom-up versus Top-down designed rehabilitation sessions in chronic stroke survivors: a pilot randomized controlled trial

Purpose The present study aimed to compare the effectiveness of Top-down and Bottom-up approaches on levels of the International Classification of Functioning, Disability and Health Framework (ICF), including impairments, activities, and participation. Materials and methods Thirty-nine chronic stroke survivors were recruited for this single-blinded randomized clinical trial. Participants were assigned to Top-down, Bottom-up interventions, or control group, and received a 6-week intervention. They were assessed before/after treatments and at follow-up (6 weeks later). Impairments were measured through kinematic analysis, Trail Making Tests (TMT), and Fugl-Meyer Assessment (FMA). Activity and participation were evaluated via Box and Block Test, Motor Activity Log (MAL), and Canadian Occupational Performance Measure (COPM), respectively. Results We found significant improvements in impairment (FMA) and participation (COPM) in all groups, however, COPM scores improved beyond the MCID only in the Top-down, and FMA scores exceeded the MCID in Top-down and Bottom-up groups. Use of the upper limb in daily activities (MAL) enhanced in the Top-down group, although was not clinically significant. Conclusion In most of the outcome measures, no significant difference was observed between groups. It seems that Top-down, Bottom-up, and traditional interventions have relatively comparable effectiveness in chronic stroke survivors. Trial Registration IRCT20150721023277N2

Brain Stroke Prediction Using Stacked Ensemble Model

Stroke is a potentially fatal illness that requires emergency care. There is a greater chance that the patient will recover and resume their regular life when they receive treatment and diagnosis as soon as feasible. Artificial Intelligence has the potential to significantly impact stroke diagnosis and facilitate prompt patient treatment for physicians. Machine learning can be utilized in stroke prediction by evaluating huge volumes of patient data and detecting patterns and risk variables that may contribute to the likelihood of a stroke. In this study, we explored a stacked ensemble model that uses four base models—Decision Tree, XGBoost, RandomForest, and ExtraTree classifiers to predict the stroke. We discovered that the accuracy of the stacked ensemble model was 96.35%, higher than that of the traditional machine-learning models, other ensemble models, and ANN model.

Alzheimer's Disease and Vascular Dementia, Connecting and Differentiating Features.

Alzheimer's disease (AD) and vascular dementia (VD) are the leading causes of dementia, presenting a significant challenge in differential diagnosis. While their clinical presentations can overlap, their underlying pathologies are distinct. AD is characterized by the accumulation of amyloid plaques and neurofibrillary tangles, leading to progressive neurodegeneration. VD, on the other hand, arises from cerebrovascular insults that disrupt blood flow to the brain, causing neuronal injury and cognitive decline. Despite distinct etiologies, AD and VD share common risk factors such as hypertension, diabetes, and hyperlipidemia. Recent research suggests a potential role for oral microbiota in both diseases, warranting further investigation. The diagnostic dilemma lies in the significant overlap of symptoms including memory loss, executive dysfunction, and personality changes. The absence of definitive biomarkers and limitations of current neuroimaging techniques necessitate a multi-modal approach integrating clinical history, cognitive assessment, and neuroimaging findings. Promising avenues for improved diagnosis include the exploration of novel biomarkers like inflammatory markers, MMPs, and circulating microRNAs. Additionally, advanced neuroimaging techniques hold promise in differentiating AD and VD by revealing characteristic cerebrovascular disease patterns and brain atrophy specific to each condition. By elucidating the complexities underlying AD and VD, we can refine diagnostic accuracy and optimize treatment strategies for this ever-growing patient population. Future research efforts should focus on identifying disease-specific biomarkers and developing more effective neuroimaging methods to achieve a definitive diagnosis and guide the development of targeted therapies.

Corticospinal premotor fibers facilitate complex motor control after stroke.

The corticospinal tract (CST) is considered the most important motor output pathway comprising fibers from the primary motor cortex (M1) and various premotor areas. Damage to its descending fibers after stroke commonly leads to motor impairment. While premotor areas are thought to critically support motor recovery after stroke, the functional role of their corticospinal output for different aspects of post-stroke motor control remains poorly understood. We assessed the differential role of CST fibers originating from premotor areas and M1 in the control of basal (single-joint muscle synergies and strength) and complex motor control (involving inter-joint coordination and visuomotor integration) using a novel diffusion imaging approach in chronic stroke patients. While M1 sub-tract anisotropy was positively correlated with basal and complex motor skills, anisotropy of PMd, PMv, and SMA sub-tracts was exclusively associated with complex motor tasks. Interestingly, patients featuring persistent motor deficits showed an additional positive association between premotor sub-tract integrity and basal motor control. While descending M1 output seems to be a prerequisite for any form of upper limb movements, complex motor skills critically depend on output from premotor areas after stroke. The additional involvement of premotor tracts in basal motor control in patients with persistent deficits emphasizes their compensatory capacity in post-stroke motor control. In summary, our findings highlight the pivotal role of descending corticospinal output from premotor areas for motor control after stroke, which thus serve as prime candidates for future interventions to amplify motor recovery.

Minimal and robust clinically important differences for patient-reported outcome measures of fatigue in chronic stroke survivors after fatigue rehabilitation

Purpose The minimal and robust clinically important difference (MCID and/or RCID) are essential in assessing the clinical significance of multidimensional fatigue inventory-20 and checklist of individual strength-fatigue subscale questionnaires changes scores. This is the first study to determine the MCID and RCID of these questionnaires in chronic stroke survivors. Materials and methods A total of 125 participants in an observational cohort study completed MFI-20 and CIS-fs before and after receiving multidisciplinary rehabilitation (cognitive behavioral therapy, graded exercise and adaptive pacing therapy). Anchor-based MCIDs and RCIDs were calculated using the mean change, the mean difference and the receiver operating characteristics methods. To evaluate the accordance between of distribution-based MCIDs (1 SD, ½ SD, SEM, 1.96 SEM and MDC values) with anchored values, the accuracy, sensitivity, specificity and Youden’s index were calculated. Results The anchored MCIDs were between −5 to −7.33 for MFI-20 and −4.87 to −5.40 for CIS-fs. The anchored RCIDs ranged from −5 to −13.88 and −6 to −9.88 for MFI-20 and CIS-fs, respectively. The values of ½ SD and SEM for CIS-fs were consistent with anchored RCIDs. Conclusions The estimated MCIDs and RCIDs of MFI-20 and CIS-fs can help researchers and clinicians interpret their chronic stroke patient data.

Memory-Guided Saccades in Subacute and Chronic Stroke: Secondary Data Analysis of the N-PEP-12 Clinical Study.

Ischemic stroke (IS) often leads to cognitive and motor impairments. This study aimed to investigate whether Memory-Guided Saccade Tasks (MGSTs) could be used to assess cognitive function in stroke patients. A secondary data analysis was conducted on 62 individuals with supratentorial IS. Eye-tracking metrics from MGST were correlated with established neuropsychological assessments, including the Montreal Cognitive Assessment (MoCA) and Hospital Anxiety and Depression Scale (HADS). Age correlated negatively with memory-guided saccade (MGS) accuracy (ρ = -0.274) and positively with late errors (ρ = 0.327). Higher Montreal Cognitive Assessment (MoCA) scores were associated with faster corrective saccades (ρ = 0.259). Increased anxiety (HADS-A) and depression (HADS-D) levels correlated with higher early error rates (ρ = 0.325 and ρ = 0.311, respectively). The Color Trails Test and Digit Span test performance also correlated with various MGS parameters. While some correlations were found between cognitive measures and eye-tracking metrics, further research is needed to validate MGST as a tool for cognitive assessment in a more homogenous stroke population.

Isolating Immune Cells from Mouse Brain and Skull.

Mounting evidence indicates that the immune response triggered by brain disorders (e.g., brain ischemia and autoimmune encephalomyelitis) occurs not only in the brain, but also in the skull. A key step toward analyzing changes in immune cell populations in both the brain and skull bone marrow after brain damage (e.g., stroke) is to obtain sufficient numbers of high-quality immune cells for downstream analyses. Here, two optimized protocols are provided for isolating immune cells from the brain and skull bone marrow. The advantages of both protocols are reflected in their simplicity, speed, and efficacy in yielding a large quantity of viable immune cells. These cells may be suitable for a range of downstream applications, such as cell sorting, flow cytometry, and transcriptomic analysis. To demonstrate the effectiveness of the protocols, immunophenotyping experiments were performed on stroke brains and normal brain skull bone marrow using flow cytometry analysis, and the results aligned with findings from published studies.

Exoskeleton-assisted upper limb rehabilitation after stroke: a randomized controlled trial

ABSTRACT Objectives The upper-limb exoskeleton training program which is repetetive and task-specific therapy can improve motor functions in patients with stroke. To compare the effect of an upper-limb exoskeleton training program with Bobath concept on upper limb motor functions in individuals with chronic stroke. Methods Participants were randomly assigned to exoskeleton group (EG, n = 12) or to Bobath group (BG, n = 12). Interventions were matched in terms of session duration and total number of sessions and performed 2 times per week for 6-weeks. Primary outcome was Fugl-Meyer- Upper Extremity (FMA-UE). Secondary outcomes were Modified Ashworth Scale (elbow and wrist flexor muscles), Motor Activity Log-30 which is consist of two parts as an amount of use (AOU) and quality of movement (QOM), and The Nottingham Extended Activities of Daily Living (NEADL) index. Results After 12-sessions of training, the mean (SD) FMA-UE score increased by 5.7 (2.9) in the EG, and 1.9 (1.5) points in the BG (p < .05). In total, 40% of participants (5/12) demonstrated a clinically meaningful improvement (≥5.25 points) in the FM-UE, while none of the participants reached MCID score in the bobath group. Changes in the AOU, QOM, and NEADL were significantly larger in the EG compared to BG (p < .05). 7/12 (58.33%) of participants for AOU and 5/12 (42%) of participants for QOM in the EG showed that clinically meaningful change. 5/12 of participants (42%) in the EG demonstrated ≥4.9-point increase in NEADL score. Discussion High-intensity repetitive arm and hand exercises with an exoskeleton device was safe and feasible. Exoskeleton-assisted training demonstrated significant benefits in improving upper limb functions and quality of life in individuals after stroke.

Transcriptomic Hallmarks of Hypoxic-Ischemic Brain Injury: Insights from an in Vitro Model.

Hypoxic-ischemic injury of neurons is a pathological process observed in several neurological conditions, including ischemic stroke and neonatal hypoxic-ischemic brain injury (HIBI). An optimal treatment strategy for these conditions remains elusive. The present study delved deeper into the molecular alterations occurring during the injury process in order to identify potential therapeutic targets. Oxygen-glucose deprivation/reperfusion (OGD/R) serves as an established in vitro model for the simulation of HIBI. This study utilized RNA sequencing to analyze rat primary hippocampal neurons that were subjected to either 0.5 or 2 h of OGD, followed by 0, 9, or 18 h of reperfusion. Differential expression analysis was conducted to identify genes dysregulated during OGD/R. Time-series analysis was used to identify genes exhibiting similar expression patterns over time. Additionally, functional enrichment analysis was conducted to explore their biological functions, and protein-protein interaction (PPI) network analyses were performed to identify hub genes. Quantitative real-time polymerase chain reaction (qRT-PCR) was used for validation of hub-gene expression. The study included a total of 24 samples. Analysis revealed distinct transcriptomic alterations after OGD/R processes, with significant dysregulation of genes such as Txnip, Btg2, Egr1 and Egr2. In the OGD process, 76 genes, in two identified clusters, showed a consistent increase in expression; functional analysis showed involvement of inflammatory responses and signaling pathways like tumor necrosis factor (TNF), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and interleukin 17 (IL-17). PPI network analysis suggested that Ccl2, Jun, Cxcl1, Ptprc, and Atf3 were potential hub genes. In the reperfusion process, 274 genes, in three clusters, showed initial upregulation followed by downregulation; functional analysis suggested association with apoptotic processes and neuronal death regulation. PPI network analysis identified Esr1, Igf-1, Edn1, Hmox1, Serpine1, and Spp1 as key hub genes. qRT-PCR validated these trends. The present study provides a comprehensive transcriptomic profile of an in vitro OGD/R process. Key hub genes and pathways were identified, offering potential targets for neuroprotection after hypoxic ischemia.

Prevalence and Impact of Malnutrition Risk on Outcomes in Critically Ill Patients with Traumatic Brain Injury and Stroke: A Retrospective Cohort Study Using Electronic Health Records.

Malnutrition is a critical concern in ICU settings. It is associated with increased morbidity and mortality, yet its prevalence and impact on clinical outcomes in patients with stroke and traumatic brain injury (TBI) remain underexplored. To evaluate the prevalence and impact of malnutrition risk on clinical outcomes in ICU patients with TBI, ischemic stroke, and hemorrhagic stroke, and to identify key risk factors associated with malnutrition risk. This retrospective cohort study utilized electronic health records encompassing ICU admissions from 2017 to 2023. Patients with either stroke or TBI were included, with malnutrition risk assessed using the prognostic nutritional index. Data were extracted and analyzed to determine patient characteristics, clinical and laboratory parameters, and outcomes. This study included 1352 patients (267 TBI, 825 ischemic stroke, and 260 hemorrhagic stroke patients, >30% with pneumonia at admission). Severe malnutrition risk at admission was observed in over 60% of patients. Stroke patients, particularly those with hemorrhagic stroke, exhibited a higher risk of malnutrition compared to TBI patients. Malnutrition risk was associated with significantly higher hospital mortality and increased need for mechanical ventilation. Predictive factors for malnutrition risk included advanced age, higher SOFA scores, lower FOUR and GCS scores, and the presence of pneumonia at admission. Risk of malnutrition is highly prevalent among ICU patients with TBI, ischemic, and hemorrhagic stroke, significantly impacting mortality and other clinical outcomes. Identifying and managing malnutrition early in the ICU setting is crucial for improving patient outcomes. Further prospective, multicenter studies are needed to validate these findings and develop effective interventions.

Systematic Insights into the Relationship between the Microbiota-Gut-Brain Axis and Stroke with the Focus on Tryptophan Metabolism.

Stroke, as a serious cerebral vascular disease with high incidence and high rates of disability and mortality, has limited therapeutic options due to the narrow time window. Compelling evidence has highlighted the significance of the gut microbiota and gut-brain axis as critical regulatory factors affecting stroke. Along the microbiota-gut-brain axis, tryptophan metabolism further acquires increasing attention for its intimate association with central nervous system diseases. For the purpose of exploring the potential role of tryptophan metabolism in stroke and providing systematic insights into the intricate connection of the microbiota-gut-brain axis with the pathological procedure of stroke, this review first summarized the practical relationship between microbiota and stroke by compiling the latest case-control research. Then, the microbiota-gut-brain axis, as well as its interaction with stroke, were comprehensively elucidated on the basis of the basic anatomical structure and physiological function. Based on the crosstalk of microbiota-gut-brain, we further focused on the tryptophan metabolism from the three major metabolic pathways, namely, the kynurenine pathway, serotonin pathway, and microbial pathway, within the axis. Moreover, the effects of tryptophan metabolism on stroke were appreciated and elaborated here, which is scarcely found in other reviews. Hopefully, the systematic illustration of the mechanisms and pathways along the microbiota-gut-brain axis will inspire more translational research from metabolic perspectives, along with more attention paid to tryptophan metabolism as a promising pharmaceutical target in order to reduce the risk of stroke, mitigate the stroke progression, and ameliorate the stroke prognosis.

Is Broca's area critical for speech and language? Evidence from lesion-symptom mapping in chronic aphasia

IntroductionThe specific role that Broca's area plays in speech and language has been hotly debated in the literature. Some research has pointed to a specific role in particular aspects of speech production, while other findings have suggested additional roles in aspects of language comprehension. In the current study, we had the opportunity to take a broad approach by analyzing lesion and behavioral data from a large cohort of left hemisphere stroke patients. In this brief report, our objective was to identify which speech-language measures show a significant association with Broca's area, specifically pars opercularis and pars triangularis.MethodsLesion site and neuropsychological data from 173 chronic left hemisphere stroke patients were analyzed in the current study. Univariate lesion-symptom mapping (LSM) with rigorous correction was used to identify brain regions associated with individual test performance on a large battery of speech and language tasks. Multivariate LSM analyses were conducted in subsequent runs to confirm findings.ResultsThe LSM results identified many predictable left hemisphere gray and white matter regions significantly associated with the speech-language data, but Broca's area was not implicated in performance on any speech or language measure. Regions adjacent to Broca's area, however, in left central opercular, precentral, and insular cortices were associated with speech production and motor speech performance.DiscussionThe current study failed to identify a single speech or language measure in our comprehensive test battery that was dependent on Broca's area. This finding could not be attributed to a lack of power, as Broca's area had among the highest power values and substantial lesion coverage. Interrogation of data at the individual patient level revealed the likely source of this null finding: Patients with lesions involving Broca's area varied widely in their speech-language performance, with profiles ranging from non-aphasic to Broca's to global aphasia. Given previous studies in acute stroke patients and healthy participants implicating Broca's area in speech-language, the current findings suggest that Broca's area plays a more supplementary than critical role and can be compensated by surrounding brain regions in chronic stroke.

Unraveling stroke gait deviations with movement analytics, more than meets the eye: a case control study.

This study aimed to identify and quantify the kinematic and kinetic gait deviations in post-stroke hemiplegic patients with matched healthy controls using Statistical Parametric Mapping (SPM). Fifteen chronic stroke patients [4 females, 11 males; age 53.7 (standard deviation 12.2) years; body mass 65.4 (10.4) kg; standing height 168.5 (9.6) cm] and 15 matched healthy controls [4 females, 11 males; age 52.9 (11.7) years; body weight 66.5 (10.7) years; standing height 168.3 (8.8) cm] were recruited. In a 10-m walking task, joint angles, ground reaction forces (GRF), and joint moments were collected, analyzed, and compared using SPM for an entire gait cycle. Generally, when comparing the stroke patients' affected (hemiplegic) and less-affected (contralateral) limbs with the control group, SPM identified significant differences in the late stance phase and early swing phase in the joint angles and moments in bilateral limbs (all p < 0.005). In addition, the vertical and anteroposterior components of GRF were significantly different in various periods of the stance phase (all p < 0.005), while the mediolateral component showed no differences between the two groups. SPM was able to detect abnormal gait patterns in both the affected and less-affected limbs of stroke patients with significant differences when compared with matched controls. The findings draw attention to significant quantifiable gait deviations in the less-affected post-stroke limb with the potential impact to inform gait retraining strategies for clinicians and physiotherapists.

Effectiveness of an institution-based adapted physical activity programme versus a home-based self-management programme for chronic poststroke adults: protocol for a randomised controlled study

IntroductionPhysical activity (PA) protects the cardiovascular system and reduces the risk of stroke recurrence. However, most stroke survivors have significantly lower daily PA levels than those recommended. Adapted PA programmes...

Non-Newtonian blood flow across stenosed elliptical artery: Case study of nanoparticles for brain disabilities with fuzzy logic

This analysis aimed to explore the blood-based non-Newtonian hybrid nanofluid flow in elliptical stenosed artery with single- and multi-walled carbon nanotubes as nanoparticles. The Carreau fluid model is incorporated to assess the non-Newtonian rheology of blood-based nanofluid for mild stenosis. In particular, the carotid artery is responsible for delivering blood to the brain. If normal blood circulation is disrupted or in the case of severe stenosis, blockage of the carotid artery can lead to the development of brain disability or stroke, which in turn can lead to death. The idealized mathematical equation is transformed into a nondimensional form and solved analytically via the perturbation method through a novel polynomial technique. These analytical solutions are explored and explained graphically. The system’s disorder and variability are assessed by completing an entropy production analysis. The disruption in blood flow due to the presence of nanoparticles causes uncertainty in the flow nature. This uncertainty is dealt with by fuzzy analysis of temperature distribution by accounting for the nanoparticle volume fractions as triangular fuzzy numbers. It is noticed that stenosis shapes and height greatly impact the flow characteristics. The nanoparticles’ percentage in fluid affected the temperature profile. The non-Newtonian characteristics of blood are found to be more dominant along the minor axis, and an effectively higher disorder is produced in this direction. It is observed that the temperature of nanofluid emerged as a triangular fuzzy number of symmetric shape.