Post-stroke Motor Research Articles

Relationships Between Cognitive Impairments and Motor Learning After Stroke: A Scoping Review.

Stroke is one of the leading causes of chronic disability worldwide. Sensorimotor recovery relies on principles of motor learning for the improvement of movement and sensorimotor function after stroke. Motor learning engages several cognitive processes to effectively learn and retain new motor skills. However, cognitive impairments are common and often coexist with motor impairments after stroke. The specific relationships between poststroke cognitive impairments and motor learning have not been determined. To summarize the existing evidence related to cognitive impairments and motor learning after stroke. Specific goals were to determine: (1) how motor learning is studied in individuals with poststroke cognitive impairments; (2) how cognitive impairments are assessed; (3) which cognitive domains impact motor learning. Over 400 studies were screened for specific inclusion criteria and 19 studies that related poststroke cognitive impairments to motor learning were included. Studies used a wide variety of experimental designs, sample sizes, and measures for cognitive evaluation. Cognitive impairments impacting motor improvement and learning capacity after stroke were reported in all but 4 studies. The most common domains impacting motor learning were attention, executive function, and memory. Detailed cognitive assessments, retention testing, and a combination of clinical and kinematic outcomes are recommended for future studies. The presence of specific cognitive impairments measured with sensitive instruments should be considered when designing effective training interventions for patients with stroke to maximize sensorimotor recovery.

Diminished sense of agency inhibits paretic upper-limb use in patients with post-stroke motor deficits

Post-stroke motor deficits often disrupt the voluntary control of body movements, leading to abnormal feelings. Among these, alterations in the sense of agency (SoA), the feeling of controlling one’s movement, are notable because SoA facilitates actions. However, whether patients with more severe motor deficits experience poorer SoA and SoA’s clinical impact on motor activity remain unclear. To address these questions, this longitudinal study quantified SoA in 156 post-stroke patients through factor analyses with multiple question items to differentiate SoA from potentially confounding discomfort. Structural equation modeling revealed that SoA decreased significantly with upper-limb motor deficit severity and that reduced SoA correlated significantly with decreased paretic upper-limb use. Notably, this effect persisted after controlling for motor deficit severity, suggesting a direct clinical impact of SoA on motor activity. Further, improvements in SoA were significantly associated with increased upper-limb use in patients with moderate or severe motor deficits, emphasizing the role of SoA in maintaining or increasing paretic upper-limb activity. These findings highlight the importance of rehabilitation treatments that consider patients' subjective experiences, particularly agency attribution.

Effect of Dual-Site Non-Invasive Brain Stimulation on Upper-Limb Function After Stroke: A Systematic Review and Meta-Analysis.

Non-invasive brain stimulation (NIBS) has attracted significant attention as it has been proven to be effective in facilitating upper limb motor recovery in patients with stroke. This meta-analysis evaluates the efficacy of dual-site non-invasive brain stimulation (DS-NIBS) in improving upper extremity motor function after stroke. A PRISMA systematic search was conducted for randomized controlled trials. Two authors independently extracted data, and the quality of included studies was assessed. Ten studies were included in the current review. DS-NIBS demonstrated a significant effect on upper extremity motor function impairment. However, only two studies showed no clear effects of DS-tDCS on upper extremity motor function after stroke. Due to the limited number of studies, the effects of DS-NIBS remain inconclusive. This review found evidence for the relatively higher efficacy of DS-NIBS on post-stroke upper extremity motor function impairment, compared to the sham and SS-NIBS. Additionally, DS-TMS was found to generate better improvement than DS-tDCS.

Comparing Interventions Used in Randomized Controlled Trials of Upper Extremity Motor Rehabilitation Post-stroke in High-Income Countries and Low-to-Middle-Income Countries

ObjectiveTo identify and compare interventions for upper extremity (UE) motor recovery poststroke in randomized controlled trials (RCTs) conducted in high-income countries (HICs) and low-to-middle-income countries (LMICs). Data SourceSystematic searches were conducted for RCTs published in English in 5 databases (CINAHL, Embase, PubMed, Scopus, and Web of Science) up to April 2021, in line with PRISMA guidelines. Study SelectionRCTs, including crossover design, were included if they were in English and evaluated an intervention for poststroke UE motor rehabilitation, in an adult population (≥18y) diagnosed with stroke. Data ExtractionData on country of origin and type of intervention in each RCT were extracted using a data extraction template in Covidence software. Study screenings and data extraction were performed by 2 independent reviewers. Data SynthesisA total of 1276 RCTs met the inclusion criteria, with 978 RCTs conducted in HICs and 298 in LMICs. A significantly larger proportion of RCTs evaluating robotics and task-specific training interventions were conducted in HICs, compared to LMICs (P<.009). In contrast, a higher proportion of RCTs conducted in LMICs examined acupuncture (P<.001) and repetitive transcranial magnetic stimulation (rTMS) (P=.001) when compared to HICs. ConclusionsPoststroke rehabilitation in LMICs is conducted in a lower resource environment when compared to HICs. Some differences exist in the use of UE motor rehabilitation interventions between LMICs and HICs such as robotics, task-specific training, rTMS, and acupuncture; however, there was no significant difference between HICs and LMICs for most interventions.

Mapping individual cortico-basal ganglia-thalamo-cortical circuits integrating structural and functional connectome: implications for upper limb motor impairment poststroke.

This study investigated alterations in functional connectivity (FC) within cortico-basal ganglia-thalamo-cortical (CBTC) circuits and identified critical connections influencing poststroke motor recovery, offering insights into optimizing brain modulation strategies to address the limitations of traditional single-target stimulation. We delineated individual-specific parallel loops of CBTC through probabilistic tracking and voxel connectivity profiles-based segmentation and calculated FC values in poststroke patients and healthy controls, comparing with conventional atlas-based FC calculation. Support vector machine (SVM) analysis distinguished poststroke patients from controls. Connectome-based predictive modeling (CPM) used FC values within CBTC circuits to predict upper limb motor function. Poststroke patients exhibited decreased ipsilesional connectivity within the individual-specific CBTC circuits. SVM analysis achieved 82.8% accuracy, 76.6% sensitivity, and 89.1% specificity using individual-specific parallel loops. Additionally, CPM featuring positive connections/all connections significantly predicted Fugl-Meyer assessment of upper extremity scores. There were no significant differences in the group comparisons of conventional atlas-based FC values, and the FC values resulted in SVM accuracy of 75.0%, sensitivity of 67.2%, and specificity of 82.8%, with no significant CPM capability. Individual-specific parallel loops show superior predictive power for assessing upper limb motor function in poststroke patients. Precise mapping of the disease-related circuits is essential for understanding poststroke brain reorganization.

Effects of repetitive transcranial magnetic stimulation at different targets on brain function in stroke patients: a randomized controlled trial.

Repetitive transcranial magnetic stimulation (rTMS) can improve post stroke motor function. However, there is little research on targets. The purpose of this study is to investigate the effects of rTMS therapy with different targets on post stroke motor function and neural plasticity. Fifty-four subjects were randomly divided into M1 (Primary motor area) group, SMA (supplementary motor area) group and Sham group, and were given 10 Hz on the affected M1 area, SMA area and sham stimulation rTMS. The primary outcomes included Fugl-Meyer Assessment Upper Extremity Scale (FMA-UE), Fugl-Meyer Assessment Lower Extremity Scale (FMA-LE) and Berg balance scale (BBS). Secondary outcomes: amplitude of low frequency fluctuation (ALFF), regional homogeneity (ReHo) and functional connectivity (FC) were analyzed by functional magnetic resonance imaging (fMRI) to evaluate brain functional activation and functional connectivity changes. The 2-way repeated-measures ANOVA revealed a significant group × time interaction (F = 23.494, p < 0.001; F = 10.801, p < 0.001; F = 17.812, p < 0.001) in the FMA-UE, FMA-LE and BBS scores. Post hoc analysis indicated that 4 weeks of SMA rTMS resulted in an increase in FMA-UE, FMA-LE and BBS scores compared with Sham group (p = 0.006; p = 0.033; p = 0.012), SMA group was significantly increased in BBS compared with M1 group (p = 0.034). Moreover, there were significant effects of time in all 3 groups in the FMA-UE, FMA-LE and BBS scores (p < 0.001). In addition, the increase of ALFF in the supramarginal gyrus on the affected side was correlated with better FMA-UE recovery, the increase of ALFF in the middle temporal gyrus and the middle frontal gyrus on the affected side was positively correlated with the improvement of BBS, and the ALFF in the cerebellum on the healthy side was negatively correlated with the improvement of BBS. There was a positive correlation between FC (SMA - ipsilateral cerebellum) changes and BBS changes in SMA group. In conclusion, SMA-rTMS intervention has a better recovery effect on motor dysfunction after stroke than Sham-rTMS. SMA-rTMS led to similar improvement on motor function but significantly greater improvement on balance compared to M1-rTMS, and this may pave a new way for stroke rehabilitation. Registration number: ChiCTR2200060955, https://www.chictr.org.cn/.

A Systematic Review of Worldwide Female Enrollment in Randomized Controlled Trials of Post-Stroke Lower Extremity Rehabilitation

Abstract This review systematically examined the reporting of sex and female participation in post-stroke lower extremity (LE) motor rehabilitation randomized controlled trials (RCTs) over time and identified differences in female participation across RCTs conducted in low-and-middle-income countries (LMICs), high-income-countries (HICs), and HIC-regions. Systematic searches were conducted of MEDLINE, Embase, CINAHL and PsycINFO from 1970 to May 2022. RCTs in English were included if they examined post-stroke LE motor rehabilitation interventions in adults diagnosed with stroke. A total of 1,285 RCTs were analyzed; 4.5% of RCTs did not report sex, and the overall female participation was 39.4%. The percentage of female participants did not significantly differ between HICs and LMICs. Within HICs, the percentage of female participants was significantly higher in European RCTs than RCTs in Asia &amp; Oceania (P = 0.008). No significant changes in female participation were found for any of the countries or regions over the last two decades. Female participation was significantly higher in RCTs conducted in the acute phase compared to those in the chronic phase (p &lt; 0.001). More research is needed to understand the reasons behind female under-enrollment and further efforts are required to ensure adequate enrollment of males and females.

Neural effects of acupuncture on stroke patients with motor dysfunction: an activation likelihood estimation meta-analysis.

Functional magnetic resonance imaging has been used in many studies to explore the neural mechanism of acupuncture in patients with post-stroke motor dysfunction. Inconsistent results have been found in these studies, however. This activation likelihood estimation (ALE) meta-analysis was designed to quantitatively integrate changes in brain activity and the neurological effects of acupuncture on patients with motor dysfunction after stroke. We searched PubMed, Embase, Web of Science, the Cochrane Library, China Science and Technology Journal Database, the China Biology Medicine, the China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform for literature from the establishment of the database until March 21, 2024. Research papers were selected, data extracted, and quality assessment was done independently by two researchers. The GingerALE software was used for meta-analysis, and Jackknife sensitivity analysis was employed to assess result robustness. We ended up analyzing 14 studies that included 235 patients and 100 healthy people. ALE meta-analysis showed that Compared with healthy people, the enhanced brain region in poststroke patients with motor dysfunction was located in the left posterior lobe of the cerebellum, the left inferior frontal gyrus, and the left precuneus (p < 0.001). After acupuncture, the activated regions were mainly located in the left posterior lobe of the cerebellum, the right lentiform nucleus putamen, the right medial frontal gyrus, the right inferior frontal gyrus, the left precuneus, the right middle temporal gyrus, the left claustrum, the left cerebellar tonsil, the right superior marginal gyrus, the inactivated area is located in the right medial frontal gyrus the left precentral gyrus and the right precuneus (p < 0.001). Acupuncture can reestablish motor function by causing extensive changes in the brain function of patients with stroke, which may be the neurological effect of acupuncture therapy on stroke patients. https://www.crd.york.ac.uk/prospero/, identifier CRD42024526263.

Effects of high-definition tDCS targeting individual motor hotspot with EMG-driven robotic hand training on upper extremity motor function: a pilot randomized controlled trial

BackgroundDelivering HD-tDCS on individual motor hotspot with optimal electric fields could overcome challenges of stroke heterogeneity, potentially facilitating neural activation and improving motor function for stroke survivors. However, the intervention effect of this personalized HD-tDCS has not been explored on post-stroke motor recovery. In this study, we aim to evaluate whether targeting individual motor hotspot with HD-tDCS followed by EMG-driven robotic hand training could further facilitate the upper extremity motor function for chronic stroke survivors.MethodsIn this pilot randomized controlled trial, eighteen chronic stroke survivors were randomly allocated into two groups. The HDtDCS-group (n = 8) received personalized HD-tDCS using task-based fMRI to guide the stimulation on individual motor hotspot. The Sham-group (n = 10) received only sham stimulation. Both groups underwent 20 sessions of training, each session began with 20 min of HD-tDCS and was then followed by 60 min of robotic hand training. Clinical scales (Fugl-meyer Upper Extremity scale, FMAUE; Modified Ashworth Scale, MAS), and neuroimaging modalities (fMRI and EEG-EMG) were conducted before, after intervention, and at 6-month follow-up. Two-way repeated measures analysis of variance was used to compare the training effect between HDtDCS- and Sham-group.ResultsHDtDCS-group demonstrated significantly better motor improvement than the Sham-group in terms of greater changes of FMAUE scores (F = 6.5, P = 0.004) and MASf (F = 3.6, P = 0.038) immediately and 6 months after the 20-session intervention. The task-based fMRI activation significantly shifted to the ipsilesional motor area in the HDtDCS-group, and this activation pattern increasingly concentrated on the motor hotspot being stimulated 6 months after training within the HDtDCS-group, whereas the increased activation is not sustainable in the Sham-group. The neuroimaging results indicate that neural plastic changes of the HDtDCS-group were guided specifically and sustained as an add-on effect of the stimulation.ConclusionsStimulating the individual motor hotspot before robotic hand training could further enhance brain activation in motor-related regions that promote better motor recovery for chronic stroke.Trial registrationThis study was retrospectively registered in ClinicalTrials.gov (ID NCT05638464).

Predictive utility of self-efficacy in early stroke rehabilitation

ABSTRACT Introduction A biopsychosocial approach entailing person-centered factors provides valuable insight to post-stroke rehabilitation potential. The consideration of an individual’s belief in their capabilities, known as self-efficacy, may prove especially informative in the inpatient rehabilitation setting where motor learning often occurs. Objective To assess the predictive utility of self-efficacy in functional independence status change during inpatient rehabilitation. Methods Individuals with stroke admitted to an inpatient rehabilitation facility (IRF) completed an assessment battery near IRF admission and discharge involving motor assessments, participant-reported self-efficacy (Stroke Self-Efficacy Questionnaire), and functional independence status evaluation (sum of self-care and mobility Quality Indicators (QI) from the IRF-Patient Assessment Instrument). Linear regression was performed to determine the predictive performance of self-efficacy on QI change during IRF stay while accounting for age, time post-stroke, and IRF length of stay. Regression procedures were repeated for separate subgroups based on initial motor impairment level. Results Thirty individuals with stroke (14 females, age = 67.0 ± 9.80 years, 10.4 ± 3.46 days post-stroke) were enrolled. Self-efficacy at IRF admission explained a significant percentage of variance in QI Change for the cohort (R2 = 30.7%, p = .001) and for the moderate to severe motor impairment subgroup (n = 12; R2 = 49.9%, p = .010). After accounting for confounders, self-efficacy remained a significant predictor for the cohort (n = 30) model. Discussion Findings generated from this work support the predictive utility of self-efficacy in early post-stroke motor recovery. The inclusion of self-efficacy in a multi-faceted evaluation framework may therefore optimize rehabilitation outcomes by providing therapists with additional knowledge to better tailor an individual’s care.

Invasive electrical nerve stimulation for post-stroke motor rehabilitation.

Invasive electrical nerve stimulation for post-stroke motor rehabilitation.

Scientific evidence of acupuncture for post-stroke motor impairment: protocol for an overview of systematic reviews and meta-analyses

IntroductionSeveral systematic reviews and meta-analyses (SRs/MAs) of clinical trials showed the efficacy of acupuncture for post-stroke motor impairment. To systematically estimate and synthesise these results, we aimed to conduct an...

Двигательные синкинезии у постинсультных больных и их реабилитационное значение. Обзор.

INTRODUCTION. Post-stroke patients often develop involuntary concomitant movements (synkinesis), which are closely related to the state of muscle tone and the nature of tendon reflexes on the side of hemiparesis. In Russia, according to the Marie-Foix classification, synkinesis is usually divided into global, imitation and coordination, and in the English-language literature terms such as “motor irradiation”, “motor overflow”, “mirror movements”, “abnormal coactivation” are used to designate them. etc. There are attempts to use these conjugal movements to restore the function of paretic limbs, but their rehabilitation value has not been sufficiently studied. AIM. Based on literature data, to study the features of pathological synkinesis in post-stroke patients, and to evaluate the possibility of their use to optimize rehabilitation methods (kinesitherapy). MATERIAL AND METHODS. The bibliographic search was performed in the scientific citation databases RSCI, PubMed, Web of Science and Scopus. The following keywords were used: "global synkinesis", "imitation synkinesis", "coordinator synkinesis", "mirror synkinesis", "motor irradiation", "abnormal coactivation", "PNF", "rehabilitation". The initial search for sources within the last 5 years did not reveal enough of them to compile a full-fledged review, for this reason, the analysis era was extended to 20 years. The main attention is paid to English-language controlled randomized trials and reviews. A total of 152 sources were analyzed, 72 of which met the specified criteria and were selected for compiling this analytical review. RESULTS AND DISCUSSION. The conducted literature analysis convinces that the basis of the traditional classification of post-stroke synkinesis by Marie-Foix should be preserved, but some additions are needed. The following types of post-stroke synkinesis should be taken into account: global, respiratory-brachial, imitative, coordinative and abnormal. In addition to kinesitherapy using proprioceptive neuromuscular facilitation, they can be used in the methods of functional electrical stimulation, bilateral training, mirror therapy, restrictive therapy according to Taub, etc. Coordinative and abnormal synkinesis are of the greatest rehabilitation value. In the residual period of stroke, persistent abnormal synkinesis can limit voluntary motor skills and require inactivation. In this case, orthopedic fixation, reflex-inhibitory positions, Perfetti therapy, the use of robotic simulators based on biofeedback and virtual reality techniques are recommended. Conclusion. The traditional Marie-Foy classification of post-stroke motor synkinesis has no alternatives but needs to be supplemented. It is advisable to distinguish the following synkinesis: global, respiratory-brachial, imitation, coordinator and anomalous global, respiratory-brachial, imitation, coordinator and anomalous. The most valuable material for kinesitherapy techniques is coordination and anomalous synkinesis. In the residual period of stroke, the remaining abnormal synkinesis limits voluntary motor activity and requires inactivation. KEYWORDS: global synkinesis, mirror synkinesis, motor irradiation, abnormal coactivation, PNF, rehabilitation

Commentary on: "effects of motor imagery-based neurofeedback training after bilateral repetitive transcranial magnetic stimulation on post-stroke upper limb motor function: an exploratory crossover clinical trial".

Abstract is missing (Commentary)

Focused magnetic stimulation for motor recovery after stroke

Background and objectivesThe effects of noninvasive focused magnetothermal brain stimulation using magnetic nanoparticles (MNPs) on post-stroke motor deficits and metabolic dormancy in subacute ischemic injury are not well-established. This study examined if magnetothermal brain stimulation using magnetic nanoparticles (Nano-MS) enhances motor recovery after stroke. MethodsWe randomly distributed rats into Sham, Control, MNP injection only, and Nano-MS groups. We administered focused magnetic stimulation for 30 min daily following an MNP injection (15 mg/mL) into the targeted motor cortex via the carotid artery three weeks after the transient (90 min) middle cerebral artery occlusion. We assessed motor functionality via behavioral tests and conducted positron emission tomography (PET) imaging to verify cerebral metabolic activity. We assessed neuronal excitability, neuroinflammation, blood-brain barrier (BBB) integrity, and neurogenesis four weeks post-stroke. ResultsThe Nano-MS group exhibited significantly improved motor deficits and cerebral metabolic activity compared to the Control and MNP groups (p < 0.05). Focused Nano-MS modulated neuronal excitability, evident by a depolarized action potential threshold for spike initiation and reduced firing frequency post-stroke. The Nano-MS group demonstrated markedly decreased inflammatory markers, such as IL-1β, IL-6, TNF-α, MCP-1, and ICAM-1, compared to the Control and MNP groups. BBB integrity and immunofluorescence for neurogenesis markers were substantially improved in the Nano-MS group. ConclusionsFocused Nano-MS facilitates the recovery of motor deficits and metabolic inactivity in the brain by effectively modulating excitability, reducing neuroinflammation, enhancing BBB stability, and promoting neurogenesis. Nano-MS is a potential novel, noninvasive therapy for stroke rehabilitation. Further investigation is warranted.

Effectiveness of repetitive transcranial magnetic stimulation combined with intelligent Gait-Adaptability Training in improving lower limb function and brain symmetry after subacute stroke: a preliminary study

ObjectivesPersistent lower limb dysfunction is a major challenge in post-stroke recovery. Repetitive transcranial magnetic stimulation is recognized for addressing post-stroke motor deficits. Our study explores the efficacy of combining rTMS with gait-adaptive training to enhance lower limb function and regulatory mechanisms in subacute stroke. Materials and methodsThis randomized controlled trial enrolled 27 patients with subacute hemiparesis, dividing them into experimental and control groups. Both groups underwent gait-adaptability training 5 times/week for 4 weeks, with the experimental group receiving daily low-frequency transcranial magnetic stimulation before training. Primary outcomes included the pairwise derived brain symmetry index, lower-extremity Fugl-Meyer Assessment, 10-meter walk test, and Berg Balance Scale. Assessments occurred before and after the four-week intervention. ResultsThe experimental and control groups showed significant improvements in the Fugl-Meyer Assessment, 10-meter walk test, and Berg Balance Scale after the 4-week intervention compared to baseline (all p<0.05). However, the experimental group demonstrated significantly greater improvements compared to the control group in the Fugl-Meyer Assessment (p=0.024) and the 10-meter walk test (p=0.033). Additionally, the experimental group exhibited a more pronounced decrease in the pairwise derived brain symmetry index (p=0.026) compared to the control group. Within the experimental group, the cortical subgroup's pairwise derived brain symmetry index was significantly lower than that of the control group (p=0.006). ConclusionsCombining low-frequency transcranial magnetic stimulation with Gait-Adaptive Training effectively enhances lower limb function and Regulatory mechanisms of the cerebral hemisphere in subacute stroke recovery, and it can provide rapid and effective rehabilitation effect compared with gait adaptation training alone.

Prediction of Upper Limb Motor Recovery by the PREP2 Algorithm in a Nonselected Population: External Validation and Influence of Cognitive Syndromes

Background Early prediction of poststroke motor recovery is challenging in clinical settings. The Prediction recovery potential (PREP2) algorithm is the most accurate approach for prediction of Upper Limb function available to date but lacks external validation. Objectives (i) To externally validate the PREP2 algorithm in a prospective cohort, (ii) to study the characteristics of patients misclassified by the algorithm, and (iii) to compare the performance according to the presence of cognitive syndromes (aphasia, neglect, cognitive disorders). Methods We enrolled 143 patients with stroke and upper extremity weakness persistent at Day 3. Evaluation to predict the recovery status according to the PREP2 algorithm included age, SAFE and NIHSS scores at Day 3 and transcranial magnetic stimulation to determine the presence of the motor-evoked potential before day seven. Actual recovery (excellent, good, limited, or poor) was defined based on the Action Research Arm test score at 3 months. Accuracy was computed by comparing the predictions of the PREP2 and the actual category of the patient. Additionally, to investigate misclassifications and the impact of cognitive syndromes, we recorded SAFE and NIHSS scores at Day 7, the Montreal Cognitive Assessment (MoCA) score, the presence of aphasia and neglect and Magnetic Resonance Imaging was used to evaluate the corticospinal tract lesion load. Results The PREP2 algorithm showed a very good predictive value with 78% accuracy [95% CI: 71.2%-86.1%], especially for the extreme categories of recovery (EXCELLENT 87.5% [95% CI: 78.9%-96.2%] and POOR 94.9% [95% CI: 87.9%-100%]), and only 46.5% [95% CI: 19.05%-73.25%] for the GOOD category and even worse than chance for the LIMITED category 0%. Pessimistic predictions (false-negative cases) had a drastic improvement in the SAFE score acutely compared to that of well-predicted patients with unfavorable recovery (P < 001). The predictive value of PREP2 decreased significantly when patients had cognitive disorders (MoCA score <24) versus not (69.4% [95% CI: 52.8%-86.1%] vs 93.1% [95% CI: 83.9%-100%], P = .01). Conclusion Our study provides an external validation of the PREP2 algorithm in a prospective population and underlines the importance of taking into account cognitive syndromes in motor recovery prediction.

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.

Hebbian plasticity induced by temporally coincident BCI enhances post-stroke motor recovery

Functional electrical stimulation (FES) can support functional restoration of a paretic limb post-stroke. Hebbian plasticity depends on temporally coinciding pre- and post-synaptic activity. A tight temporal relationship between motor cortical (MC) activity associated with attempted movement and FES-generated visuo-proprioceptive feedback is hypothesized to enhance motor recovery. Using a brain–computer interface (BCI) to classify MC spectral power in electroencephalographic (EEG) signals to trigger FES-delivery with detection of movement attempts improved motor outcomes in chronic stroke patients. We hypothesized that heightened neural plasticity earlier post-stroke would further enhance corticomuscular functional connectivity and motor recovery. We compared subcortical non-dominant hemisphere stroke patients in BCI-FES and Random-FES (FES temporally independent of MC movement attempt detection) groups. The primary outcome measure was the Fugl-Meyer Assessment, Upper Extremity (FMA-UE). We recorded high-density EEG and transcranial magnetic stimulation-induced motor evoked potentials before and after treatment. The BCI group showed greater: FMA-UE improvement; motor evoked potential amplitude; beta oscillatory power and long-range temporal correlation reduction over contralateral MC; and corticomuscular coherence with contralateral MC. These changes are consistent with enhanced post-stroke motor improvement when movement is synchronized with MC activity reflecting attempted movement.

Facilitating Corticomotor Excitability of the Contralesional Hemisphere Using Non-Invasive Brain Stimulation to Improve Upper Limb Motor Recovery from Stroke-A Scoping Review.

Upper limb weakness following stroke poses a significant global psychosocial and economic burden. Non-invasive brain stimulation (NIBS) is a potential adjunctive treatment in rehabilitation. However, traditional approaches to rebalance interhemispheric inhibition may not be effective for all patients. The supportive role of the contralesional hemisphere in recovery of upper limb motor function has been supported by animal and clinical studies, particularly for those with severe strokes. This review aims to provide an overview of the facilitation role of the contralesional hemisphere for post-stroke motor recovery. While more studies are required to predict responses and inform the choice of NIBS approach, contralesional facilitation may offer new hope for patients in whom traditional rehabilitation and NIBS approaches have failed.