Search

Reduced propulsion of the paretic leg contributes to impaired walking in people poststroke. The goal of this study was to determine whether phasic electrical stimulation to the paretic gastrocnemius muscle combined with resistance applied to the nonparetic leg during swing phase while walking would enhance muscle activation of the paretic gastrocnemius and propulsive force of the paretic leg. Fifteen individuals who had a stroke visited the lab once to complete two experimental sessions (i.e., crossover design; session order randomized). Each session consisted of 1 ) treadmill walking with either "motor stimulation and swing resistance" or "swing resistance only" (10-min walking: 1-min baseline, 7-min adaptation to intervention, and 2-min postadaptation) and 2 ) instrumented treadmill walking before and after treadmill walking. Participants showed enhanced muscle activation of the paretic gastrocnemius ( P = 0.03) and improved anteroposterior ground reaction force of the paretic leg ( P = 0.01) immediately after the treadmill walking with "motor stimulation and swing resistance," whereas no improvements after the walking with "swing resistance only." Those enhanced gastrocnemius muscle activation ( P = 0.02) and improved ground reaction force ( P = 0.03) were retained until the late postadaptation period and 10 min after treadmill walking, respectively. Walking with "motor stimulation and swing resistance" may enhance forced use of the paretic leg and improve propulsive force of the paretic leg. Applying phasic electrical stimulation to the paretic gastrocnemius muscle and swing resistance to the nonparetic leg during walking can be used as a novel intervention strategy to improve motor control of the paretic leg and walking in people poststroke. NEW & NOTEWORTHY Applying targeted motor stimulation to the paretic calf muscle and swing resistance to the nonparetic leg during walking induced significant enhancement in muscle activation of the paretic gastrocnemius and anterior-posterior ground reaction force of the paretic leg, whereas no enhancements were observed after walking with swing resistance only. Furthermore, the enhanced gastrocnemius muscle activation and ground reaction force of the paretic leg were partially retained at the late postadaptation period and 10 min after treadmill walking.

Background: Functional correlates of spastic myopathy, the muscle disorder of spastic paresis, are unknown., Objective: To explore reciprocal relationships between clinical and structural parameters of plantar flexors with i) ambulation speed, ii) dorsiflexion and plantarflexion torques in chronic hemiparesis., Methods: Cross-sectional trial in chronic stroke-induced hemiparesis (>6 months). Plantar flexors were quantified through i) the Five Step Assessment: maximal extensibility (XV1), active range of dorsiflexion (XA); ii) ultrasonography: fascicle length (Lf) and thickness (Th) of medial gastrocnemius (GAS) and soleus (SOL), knee extended in an isokinetic ergometer, ankle at 80% XV1-GAS. Maximal isometric torques in plantar flexion (PF) and dorsiflexion (DF) and maximal barefoot 10-meter ambulation speed were collected. Relationships between structural, biomechanical, clinical and functional parameters were explored using non-parametric testing (Spearman)., Results: Twenty-one subjects (age 58.0±8.4, mean±SD, time since lesion 7.8±5.7 years) were recruited, with the following characteristics: ambulation speed, 0.77±0.37m/sec; XV1-SOL 92.7±10.3°; XV1-GAS 91.3±9.6°; XA-SOL 86.9±10.0°; XA-GAS 7676±14.2°; LfGAS, 58.2±18.3mm; ThGAS, 17.1±3.6 mm; LfSOL, 36.0±9.6 mm; ThSOL, 13.8±3.3mm; PF peak-torque 46.5±34.1Nm, DF peak-torque, 20.1±19.1Nm. XA-SOL and XA-GAS strongly correlated with XV1-SOL and XV1-GAS respectively (ρ = 0.74, p = 4E-04; resp ρ = 0.60, p = 0.0052). Ambulation speed moderately correlated with LfGAS (ρ = 0.51, p = 0.054), ThGAS (ρ = 0.58, p = 0.02) and LfSOL (ρ = 0.63, p = 0.009). DF and PF peak-torques both correlated with LfGAS (ρ = 0.53, p = 0.04) a; resp. ρ = 0.71, p = 0.0015)., Conclusion: In chronic hemiparesis, active dorsiflexion is mostly determined by plantar flexor extensibility. Plantar flexor fascicle shortening is associated with reduced ambulation speed and ankle torques. Attempts to restore plantar flexor extensibility might be important objectives for gait rehabilitation in chronic hemiparesis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pradines et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This study investigated the treatment methods used by physical and occupational therapists for poststroke paretic upper limbs and the factors influencing their decision-making processes. For the treatment methods of poststroke paretic upper limbs, the respondents were asked to select the most clinically used treatment according to the severity of the patient's condition. For the factors influencing their decision-making processes, the respondents were asked to indicate each determinant using a 5-point Likert scale (1 =  no influence at all to 5 =  very strong influence ). Six hundred thirty-eight therapists participated in this study. Exploratory factor analysis was used to assess the validity of the questionnaire. The findings indicated task-specific training ( N = 333, 52%) as the most popular for mild cases, followed by repetitive facilitative exercise ( n = 143, 22.3%) for moderate cases and electrical stimulation ( n = 246, 38.4%) for severe cases. This study revealed that evidence about treatment (very strong: n = 171 (27.0%), and strong: n = 287 (45.0%)) and patient preferences (very strong: n = 203 (31.8%), and strong: n = 251 (39.3%)) affected decision-making significantly regarding treatment methods for the poststroke paretic upper limb., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Koichiro Hirayama et al.)

Motor learning involves both explicit and implicit processes that are fundamental for acquiring and adapting complex motor skills. However, stroke may damage the neural substrates underlying explicit and/or implicit learning, leading to deficits in overall motor performance. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke when tested during a task that elicits dissociable contributions from both. Here, we compared explicit and implicit locomotor learning in individuals with chronic stroke to age- and sex-matched neurologically intact controls. We assessed implicit learning using split-belt adaptation (where two treadmill belts move at different speeds). We assessed explicit learning (i.e., strategy-use) using visual feedback during split-belt walking to help individuals explicitly correct for step length errors created by the split-belts. After the first 40 strides of split-belt walking, we removed the visual feedback and instructed individuals to walk comfortably, a manipulation intended to minimize contributions from explicit learning. We used a multirate state-space model to characterize individual explicit and implicit process contributions to overall behavioral change. The computational and behavioral analyses revealed that, compared with controls, individuals with chronic stroke demonstrated deficits in both explicit and implicit contributions to locomotor learning, a result that runs counter to prior work testing each process individually during gait. Since poststroke locomotor rehabilitation involves interventions that rely on both explicit and implicit motor learning, future work should determine how locomotor rehabilitation interventions can be structured to optimize overall motor learning. NEW & NOTEWORTHY Motor learning involves both implicit and explicit processes, the underlying neural substrates of which could be damaged after stroke. Although both learning processes are typically used in concert in daily life and rehabilitation, no gait studies have determined how these processes function together after stroke. Using a locomotor task that elicits dissociable contributions from both processes and computational modeling, we found evidence that chronic stroke causes deficits in both explicit and implicit locomotor learning.

Background and Purpose: Functional recovery after stroke is often limited, despite various treatment methods such as robot-assisted therapy. Repetitive sensory stimulation (RSS) might be a promising add-on therapy that is thought to directly drive plasticity processes. First positive effects on sensorimotor function have been shown. However, clinical studies are scarce, and the effect of RSS combined with robot-assisted training has not been evaluated yet. Therefore, our objective was to investigate the feasibility and sensorimotor effects of RSS (compared to a control group receiving sham stimulation) followed by robot-assisted arm therapy., Methods: Forty participants in the subacute phase (4.4-23.9 weeks) after stroke with a moderate to severe arm paresis were randomized to RSS or control group. Participants received 12 sessions of (sham-) stimulation within 3 weeks. Stimulation of the fingertips and the robot-assisted therapy were each applied in 45-min sessions. Motor and sensory outcome assessments (e.g. Fugl-Meyer-Assessment, grip strength) were measured at baseline, post intervention and at a 3-week follow-up., Results: Participants in both groups improved their sensorimotor function from baseline to post and follow-up measurements, as illustrated by most motor and sensory outcome assessments. However, no significant group effects were found for any measures at any time ( P > 0.058). Stimulations were well accepted, no safety issues arose., Discussion and Conclusions: Feasibility of robot-assisted therapy with preceding RSS in persons with moderate to severe paresis was demonstrated. However, RSS preceding robot-assisted training failed to show a preliminary effect compared to the control intervention. Participants might have been too severely affected to identify changes driven by the RSS, or these might have been diluted or more difficult to identify because of the additional robotic training and neurorehabilitation., Video Abstract Available: for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A478 )., Competing Interests: There are no conflicts of interest to declare., (Copyright © 2024 Academy of Neurologic Physical Therapy, APTA.)

Background: The purpose of this study was to establish consensus statements via a modified Delphi process on the definition of shoulder pseudoparalysis and pseudoparesis., Methods: A consensus process on the definition of a diagnosis of pseudoparalysis utilizing a modified Delphi technique was conducted, and 26 shoulder/sports surgeons from 11 countries, selected based on their level of expertise in the field, participated in these consensus statements. Consensus was defined as achieving 80%-89% agreement, whereas strong consensus was defined as 90%-99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement., Results: Three statements regarding the diagnosis of pseudoparalysis reached strong (>89%) consensus: passive range of motion should be unaffected, the passive range of abduction should not be considered, and diagnosis should be excluded if lidocaine injection produces a substantial improvement in range of motion. Additionally, consensus (>79%) was reached that the active range of external rotation should not be considered for diagnosis, pain as a cause of restricted motion must be excluded, and that distinctions between restricted active flexion and external rotation should be made by range of motion rather than tear characteristics. No consensus could be reached on statements regarding the size, number of tendons or chronicity of cuff tears. Nor was there agreement on the active range of flexion permitted or on the difference between pseudoparalysis and pseudoparesis., Conclusion: A modified Delphi process was utilized to establish consensus on the definition of shoulder pseudoparalysis and pseudoparesis. Unfortunately, almost half of the statements did not reach consensus, and agreement could not be reached across all domains for a unifying definition for the diagnosis of pseudoparalysis in the setting of rotator cuff tears. Furthermore, it was not agreed how or whether pseudoparalysis should be differentiated from pseudoparesis. Based on the lack of a consensus for these terms, studies should report explicitly how these terms are defined when they are used., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The quantification of electromyographic activity using surface electrodes is invaluable for understanding gait disorders in patients with central nervous system lesions. We propose to evaluate a commercially available low-cost system compared to a reference system in participants with stroke-related movement disorders in functional situations., Methods: Three hemiparetic participants performed three functional tasks: two treadmill walks at different speeds and a sit-to-stand test. The vastus lateralis and gastrocnemius medialis muscles were equipped with two EMG sensors. The comparison between the two EMG systems was based on 883 identified cycles. Spearman's correlation coefficients (SCs), linear correlation coefficients (LCCs), and cross-correlation coefficients (CCCs) were calculated., Results: The main results indicate good to very good similarity of the EMG signals collected from the two tested sEMG systems. In the comfortable-walking condition, an SC of 0.894 ± 0.091 and an LCC of 0.909 ± 0.094 were noted. In the fast-walking condition, an SC of 0.918 ± 0.064 and an LCC of 0.935 ± 0.056 were observed. For the 1 min sit-to-stand test, an SC of 0.880 ± 0.058 and an LCC of 0.881 ± 0.065 were noted., Conclusions: This study demonstrates good to very good similarity between the two sEMG systems, enabling the analysis of muscle activity during functional tasks.

Background: It has long been of interest to characterize the components of the motor abnormality in the arm after stroke. One approach has been to decompose the hemiparesis phenotype into negative signs, such as weakness, and positive signs, such as intrusion of synergies. We sought to identify the contributions of weakness and flexor synergy to motor deficits in sub-acute stroke., Methods: Thirty-three sub-acute post-stroke participants and 16 healthy controls performed two functional arm movements; one within flexor synergy (shoulder and elbow flexion), and the other outside flexor synergy (shoulder flexion and elbow extension). We analyzed upper limb 3D kinematics to assess both overall task performance and intrusion of pathological synergies. Weakness and spasticity were also measured., Results: Both tasks produced similar impairments compared to controls. Analysis of elbow and shoulder multi-joint coordination patterns revealed intrusion of synergies in the out-of-synergy reaching task based on the time spent within a flexion-flexion pattern and the correlation between shoulder and elbow angles. Regression analysis indicated that both weakness and synergy intrusion contributed to motor impairment in the out-of-synergy reaching task. Notably, the Fugl-Meyer Assessment (FMA) was abnormal even when only weakness caused the impairment, cautioning that it is not a pure synergy scale., Conclusions: Weakness and synergy intrusion contribute to motor deficits in the sub-acute post-stroke period. An abnormal FMA score cannot be assumed to be due to synergy intrusion. Careful kinematic analysis of naturalistic movements is required to better characterize the contribution of negative and positive signs to upper limb impairment after stroke., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To assess the effectiveness of alternating hot-cold water immersion (AHCWI) in patients with acute stroke., Design: A single-blind pilot randomized controlled trial., Setting: Department of Rehabilitation Medicine of a medical center., Participants: Early stroke survivors (N=24) with moderate-to-severe arm paresis., Interventions: In addition to conventional rehabilitation, eligible patients were randomly assigned to an AHCWI group (n=12, for AHCWI) or a control group (n=12, for upper limb [UL] cycling exercises) 5 times per week for 6 weeks., Main Outcome Measures: The Fugl-Meyer Assessment motor-UL (FMA-UL) score, Motricity Index-UL (MI-UL) score, modified Motor Assessment Scale (MMAS; including its UL sections, MMAS-UL) score, Berg Balance Scale score, Barthel Index (BI), and modified Ashworth Scale score were assessed by the same uninvolved physical therapist at baseline and after 4 and 6 weeks of intervention., Results: Compared with the control group, the AHCWI group performed better, with significant group effects (P<.05), and exhibited significant improvements in FMA-UL, MI-UL, and MMAS-UL scores at 4 and 6 weeks (P<.05). Although the remaining outcomes were not significantly different, they favored the AHCWI group. Notably, a significant difference was observed in the BI at 4 weeks (P=.032). Significant changes in the muscle tone or adverse effects were not observed in either group after the intervention., Conclusions: AHCWI with stroke rehabilitation is feasible and may facilitate motor function recovery of the paretic UL after a stroke., (Copyright © 2024 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Post-stroke hemiparetic gait exhibits considerable variations in motion patterns and abnormal muscle activities, notably knee hyperextension during the stance phase. Existing studies have primarily concentrated on its joint angle or moment. However, the underlying causes remain unclear. Thus, the causes of knee hyperextension were explored from a new perspective based on temporal-durational factors., Research Question: Does the temporal-durational difference of knee hyperextension presence result from specific decreased motor functions?, Methods: Barefoot gait at a comfortable speed was captured using a three-dimensional camera system. Scores of knee hyperextension used a metric with the temporal-durational factor of knee hyperextension presence in each of four stance phases (1st double support, DS1; early single-leg stance, ESS; late single-leg stance, LSS; 2nd double support, DS2). These scores were used in cluster analysis. The classification and regression tree analysis characterizing each knee hyperextension cluster used the clinical measures of the lower limb and trunk motor function, muscle strength, and spasticity as explanatory variables., Results: Thirty patients with hemiparetic chronic stroke who exhibited knee hyperextension during gait were included. Four knee hyperextension clusters were shown: Momentary (almost no hyperextension), Continuous (DS1-DS2), ESS-LSS, and ESS-DS2. Knee flexor strength was lower in the groups with long hyperextension durations (Continuous and ESS-DS2) compared with short durations (ESS-LSS and Momentary). ESS-DS2 exhibited higher trunk motor function than Continuous, whereas more severe spasticity was observed in ESS-LSS than in Momentary., Significance: This study successfully classified four hemiparetic gait patterns with knee hyperextension based on the temporal-durational factor, providing valuable perspectives for understanding and addressing specific functional physical impairments. These findings offer guidance for focusing on related physical functions when striving for gait improvement with knee hyperextension and are expected to serve as a reference for treatment decision-making., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: An ankle-foot orthosis (AFO) with plantar flexion resistance (PFR) can improve the first rocker function during gait, but the incremental changes in the resistive moment on balance and gait have not been well identified., Objectives: To investigate the effect of changing the PFR moment of dynamic AFO (DAFO) on measures of the center of pressure (COP) and clinical gait outcomes in individuals with post-stroke hemiparesis., Method: In this randomized repeated measure study of 36 stroke individuals, the customized DAFO using foot drop ankle units set in three PFR situations (low, medium, and high) was evaluated. The balance parameters for COP measures were investigated by HUMAC® Balance & Tilt System. Gait parameters and ankle kinematics were recorded using the 3D motion analysis through force platform and optoelectronic system. The comparison was made using a parametric ANOVA test and the P value was set at 0.05 for statistical significance., Results: Significant differences were observed for COP average velocity (1.30 ± 0.64, 1.10 ± 0.05, and 1.37 ± 0.43), COP path length (43.3 ± 4.6, 33.4 ± 4.3, and 36.3 ± 5.4), walking velocity (11.0 ± 3.1, 13.2 ± 4.4, and 9.9 ± 3.5), and cadence (31.5 ± 2.0, 33.0 ± 3.1, and 29.0 ± 1.6) respectively for low, medium and high PFR settings (P < 0.05). Except for the COP path length and cadence, posthoc multiple comparisons revealed significant differences between low and medium (P < 0.05) and medium and high (P < 0.05) PFR grades. PFR with medium resistance demonstrated near-normal maximal peak ankle dorsiflexion (mean deviation of 8 degrees, P < 0.05)., Conclusion: Medium PFR grade should be encouraged since it can enhance balance parameters like path length and average velocity of COP, increase cadence and average velocity during gait, and improve maximal peak ankle dorsiflexion., Competing Interests: Declaration of Competing Interest We have no conflict of Interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Motor interference, where new skill acquisition disrupts the performance of a previously learned skill, is a critical yet underexplored factor in gait rehabilitation post-stroke. This study investigates the interference effects of two different practice schedules, applying interleaved (ABA condition) and intermittent (A-A condition) pulling force to the pelvis during treadmill walking, on lateral pelvis shifting towards the paretic leg in individuals with stroke. Task A involved applying resistive pelvis force (pulling towards the non-paretic side), and Task B applied assistive force (pulling towards the paretic side) at the stance phase of the paretic leg during walking. Sixteen individuals with chronic stroke were tested for gait pattern changes, including lateral pelvis shifting and spatiotemporal gait parameters, and neurophysiological changes, including muscle activity in the paretic leg and beta band absolute power in the lesioned cortical areas. A-A condition demonstrated increased lateral pelvis shifting towards the paretic side, extended paretic stance time and longer non-paretic step length after force release while ABA condition did not show any changes. These changes in gait pattern after A-A condition were accompanied by increased muscle activities of the ankle plantarflexors, and hip adductors/abductors. A-A condition demonstrated greater changes in beta band power in the sensorimotor regions compared to ABA condition. These findings suggest that while walking practice with external force to the pelvis can improve lateral pelvis shifting towards the paretic leg post-stroke, practicing a new pelvis shifting task in close succession may hinder the performance of a previously obtained lateral pelvis shifting pattern during walking., (© 2024 The Author(s). European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

The goal of this study was to determine the effects of applying random vs. constant constraint force to the non-paretic leg during walking on enhanced use of the paretic leg in individuals post-stroke, and examine the underlying brain mechanisms. Twelve individuals with chronic stroke were tested under two conditions while walking on a treadmill: random vs. constant magnitude of constraint force applied to the non-paretic leg during swing phase of gait using a custom designed robotic system. Leg kinematics, muscle activity of the paretic leg, and electroencephalography (EEG) were recorded during treadmill walking. Paretic step length and muscle activity of the paretic ankle plantarflexors significantly increased after walking with random and constant constraint forces. Cortico-cortical connectivity between motor cortices and cortico-muscular connectivity from the lesioned motor cortex to the paretic ankle plantarflexors significantly increased for the random force condition but not for the constant force condition. In addition, individuals post-stroke with greater baseline gait variability showed greater improvements in the paretic step length after walking with random force condition but not with the constant force condition. In conclusion, application of random constraint force to the non-paretic leg may enhance the use of the paretic leg during walking by facilitating cortical drive from the lesioned motor cortex to the paretic ankle plantarflexors. Results from this study may be used for the development of constraint induced locomotor intervention approaches aimed at improving locomotor function in individuals after stroke., Competing Interests: Declarations Competing interests The authors report no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Stroke is a heterogeneous condition, making choice of treatment, and determination of how to structure rehabilitation outcomes difficult. Individualized goal-directed and repetitive physical practice is an important determinant of motor learning. Yet, many investigations of motor learning after stroke deliver task practice without consideration of individual capability of the learner., Objective: We developed a gamified arm rehabilitation task for people with stroke that is personalized to individual capacity for paretic arm movement, provides a high dose of practice, progresses through increasingly difficulty levels that are dependent on the performance of the individual, and is practiced in an engaging environment. The objectives of the current study were to determine if 10 days of gamified, object intercept training using the paretic arm would improve arm movement speed and clinical outcome measures of impairment or function., Methods: Individuals with chronic stroke and age-matched controls engaged in 10 days of gamified, skilled motor practice of a semi-immersive virtual reality-based intercept and release task. The paretic arm was assessed using the Fugl-Meyer Assessment (motor impairment) and Wolf Motor Function Test (motor function) before and after training., Results: Both groups showed faster arm movement speed with practice; individuals with stroke demonstrated reduced paretic arm motor impairment and increased function after the intervention. Age and sex (for both groups), and time post-stroke were not related to changes in movement speed., Conclusions: Findings indicate that gamified motor training positively affects paretic arm motor behavior in individuals with mild to severe chronic stroke., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Aim: The aim of this study was to make the Turkish cultural adaptation of the the Stroke Activity Scale (SAS)., Method: This study was designed as a methodological research. The psychometric properties of the SAS scale were evaluated by validity and reliability analyses., Results: The average age of 84 stroke patients (mean ± SD) was 59.52 ± 14.03 years. Kaiser-Meyer-Olkin (0.816) and Bartlett's Test of Sphericity (χ2 = 288.968, df = 10, p  < 0.001) showed that the data set can be factored. A one-factor structure was obtained with Principal Component Analysis (PCA). The factor loads of the items obtained with PCA and Confirmatory Factor Analysis (CFA) were found to be statistically significant. The obtained chi-square statistics (χ2 = 2.227, p  = 0.694), normalized chi-square/freedom (χ2/sd) value (0 ≤ 0.557 ≤ 2) and other goodness of fit indices showed good compliance. The positive highly significant correlation ( r  = 0.846, p  < 0.001) between the SAS and Rivermead Mobility Index (RMI) scales confirmed the Concurrent validity. Cronbach's alpha (0.864) value showed high reliability and Intraclass Correlation Coefficient (ICC) value (0.983, p  < 0.001) showed excellent agreement., Conclusions: In this study, which was conducted for the Turkish adaptation of the SAS scale, the 5-item and 1-factor structure was evaluated as a valid and reliable scale for evaluating the balance abilities of stroke patients living in Turkey.

Objectives: Persistent 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 Methods: This 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., Results: The 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)., Conclusions: Combining 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., Competing Interests: Declaration of competing interest The Authors declare that there is no conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Stroke often causes long-term motor and somatosensory impairments. Motor planning and tactile perception rely on spatial body representations. However, the link between altered spatial body representations, motor deficit and tactile spatial coding remains unclear. This study investigates the relationship between motor deficits and alterations of anatomical (body) and tactile spatial representations of the hand in 20 post-stroke patients with upper limb hemiparesis. Anatomical and tactile spatial representations were assessed from 10 targets (nails and knuckles) respectively cued verbally by their anatomical name or using tactile stimulations. Two distance metrics (hand width and finger length) and two structural measures (relative organization of targets positions and angular deviation of fingers from their physical posture) were computed and compared to clinical assessments, normative data and lesions sites. Over half of the patients had altered anatomical and/or tactile spatial representations. Metrics of tactile and anatomical representations showed common variations, where a wider hand representation was linked to more severe motor deficits. In contrast, alterations in structural measures were not concomitantly observed in tactile and anatomical representations and did not correlate with clinical assessments. Finally, a preliminary analysis showed that specific alterations in tactile structural measures were associated with dorsolateral prefrontal stroke lesions. This study reveals shared and distinct characteristics of anatomical and tactile hand spatial representations, reflecting different mechanisms that can be affected differently after stroke: metrics and location of tactile and anatomical representations were partially shared while the structural measures of tactile and anatomical representations had distinct characteristics., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Upper limb (UL) spastic paresis has been classically evaluated with assessments of passive movements with limited functional validity. The aim of this study was to assess whether a composite measure of active range of motion (AROM, or XA) is valid and reliable in chronic post-stroke spastic paresis., Aim: The primary objective was to investigate the validity and reliability of a composite score, comprising multiple XA measurements, to assess UL spastic paresis in patients in chronic stages post-stroke. In addition to this, an exploratory analysis was conducted to identify which muscles should be optimally included in this composite score., Design: A psychometric proprieties study., Setting: Physical and Rehabilitation Medicine Department., Population: twenty-eight chronic post-stroke participants with spastic paresis., Methods: Composite UL XA measurement in twenty-eight chronic post-stroke participants (age=59±11 years; delay post-stroke=29±37 months) with spastic paresis was repeated twice about 40 days apart in a standardized body position. Concurrent and construct validity was evaluated exploring correlation with the Fugl-Meyer Assessment Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), and grip strength (JAMAR™). Reliability was assessed by calculating intraclass correlation coefficients (ICC). Regarding the exploratory analysis, a linear regression analysis was performed to examine the value of including various muscles., Results: Composite XA against the resistance of elbow, wrist and finger flexors showed strong correlation with FMA-UE and ARAT (r=0.88; P<0.001 and r=0.82; P<0.001 respectively) and a weak association with grip strength (r=0.43; P=0.03). Test-retest reliability was excellent (ICC=0.92). However, the most effective regression model also included XA against the resistance of shoulder adductors as well as forearm pronator (adjusted R 2 =0.85; AIC=170)., Conclusions: The present study provided satisfactory psychometric data for the upper limb composite active movement (CXA), derived from the Five Step Assessment. For overall measurement of UL mobility after stroke, we strongly recommend including shoulder and forearm muscles to the score., Clinical Rehabilitation Impact: Composite XA is a valid and reliable measure of upper limb motor function in chronic post-stroke patients and could be used in clinical practice and research.

Objective: Depth camera-based measurement has demonstrated efficacy in automated assessment of upper limb Fugl-Meyer Assessment for paralysis rehabilitation. However, there is a lack of adequately sized studies to provide clinical support. Thus, we developed an automated system utilizing depth camera and machine learning, and assessed its feasibility and validity in a clinical setting., Design: Validation and feasibility study of a measurement instrument based on single cross-sectional data., Setting: Rehabilitation unit in a general hospital., Participants: Ninety-five patients with hemiparesis admitted for inpatient rehabilitation unit (2021-2023)., Main Measures: Scores for each item, excluding those related to reflexes, were computed utilizing machine learning models trained on participant videos and readouts from force test devices, while the remaining reflex scores were derived through regression algorithms. Concurrent criterion validity was evaluated using sensitivity, specificity, percent agreement and Cohen's Kappa coefficient for ordinal scores of individual items, as well as correlations and intraclass correlation coefficients for total scores. Video-based manual assessment was also conducted and compared to the automated tools., Result: The majority of patients completed the assessment without therapist intervention. The automated scoring models demonstrated superior validity compared to video-based manual assessment across most items. The total scores derived from the automated assessment exhibited a high coefficient of 0.960. However, the validity of force test items utilizing force sensing resistors was relatively low., Conclusion: The integration of depth camera technology and machine learning models for automated Fugl-Meyer Assessment demonstrated acceptable validity and feasibility, suggesting its potential as a valuable tool in rehabilitation assessment., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

BACKGROUND General paresis of the insane (GPI) is characterized by cognitive impairment, neuropsychiatric symptoms, and brain structural abnormalities, mimicking many neuropsychiatric diseases. Olfactory dysfunction has been linked to cognitive decline and neuropsychiatric symptoms in numerous neuropsychiatric diseases. Nevertheless, it remains unclear whether patients with GPI experience olfactory dysfunction and whether olfactory dysfunction is associated with their clinical manifestations. MATERIAL AND METHODS Forty patients with GPI and 37 healthy controls (HCs) underwent the "Sniffin Sticks" test battery, Mini-Mental State Examination, and Neuropsychiatric Inventory to measure olfactory function, cognitive function, and neuropsychiatric symptoms, respectively. Brain structural abnormalities were evaluated using visual assessment scales including the medial temporal lobe atrophy (MTA) visual rating scale and Fazekas scale. RESULTS Compared with HCs, patients with GPI exhibited significant olfactory dysfunction, as indicated by deficits in the odor threshold (OT) (P=0.001), odor discrimination (OD) (P<0.001), and odor identification (OI) (P<0.001). In patients with GPI, the OI was positively correlated with cognitive function (r=0.57, P<0.001), but no significant correlation was found between olfactory function and neuropsychiatric symptoms, blood, or cerebrospinal fluid biomarkers (rapid plasma reagin circle card test and Treponema pallidum particle agglutination test), or brain structural abnormalities (MTA and Fazekas scale scores). Mediation analysis indicated that the impaired OI in patients with GPI was mediated by cognitive impairment and impaired OT respectively. CONCLUSIONS Patients with GPI exhibited overall olfactory dysfunction. OI is correlated with cognitive function and the impaired OI is mediated by cognitive impairment in patients with GPI. Thus, OI may serve as a marker for reflecting cognitive function in patients with GPI.

Background: Ataxic hemiparesis (AH) is a well-recognized clinical lacunar stroke syndrome, characterized by paresis with ataxia on the same side of the body. It affects patients with stroke involving the basal ganglia, pons, internal capsule, corona radiata, and thalamus. In the past, lacunar syndrome denotes good functional recovery with low mortality and morbidity rate. However, recent evidence suggests AH has an association with more debilitating outcomes in the long term., Objective: To provide a comprehensive narrative review of published literatures on the topics related with AH and update clinical practice including rehabilitation., Methods: Literature review was performed by using the keywords "Subcortical Ataxia," "Lacunar Stroke," "Diaschisis", and "Ataxic Hemiparesis" on PubMed and Google Scholar Engines from 1978 to 2022. All papers published in English were reviewed and manual search of references from retrieved literature was performed for other relevant articles., Results: A comprehensive review was carried out on the following topics: neuroanatomical localization, pathogenesis, clinical features and clinical assessment scales, pharmacological and non-pharmacological modalities for ataxia treatment, prognosis, and outcome., Conclusion: AH imposes significant challenges on stroke survivors when it comes to remediation of balance and coordination. It is associated with increased risk of mortality, stroke recurrence, and dementia. Though application of the concept of neuroplasticity and the utilization of repetitive transcranial magnetic stimulation have shown early promising results, further research is needed to establish the practice guidelines for rehabilitation of patients with AH.

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations ( r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke ( P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations. NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Background: Few studies have examined changes in skeletal muscle physiology post-stroke. This study examined changes in tissue oxygen saturation (StO 2 ) of the vastus lateralis (VL) muscle of stroke survivors and age-matched control participants during maximal and submaximal isometric contractions of the knee extensor muscles., Objectives: We hypothesized that tissue oxygen desaturation (ΔStO 2 ) during knee extensor muscle contractions would be less in the VL in the paretic vs. the non-paretic and control legs., Methods: Ten chronic stroke survivors (>6 months post-stroke) with lower extremity muscle weakness and 10 age-matched controls completed this prospective cohort study. Maximum voluntary contractions (MVCs) of the knee extensor muscles were assessed with a Biodex dynamometer and StO 2 of the VL was measured using near-infrared spectroscopy., Results: In the paretic leg of the stroke survivors little change in StO 2 of the VL was observed during an MVC (ΔStO 2  = -1.7 ± 1.8%) compared to the non-paretic (ΔStO 2  = -5.1 ± 6.1%; p  < 0.05) and control legs (ΔStO 2  = -14.4 ± 8.8%; p  < 0.05 vs. paretic and non-paretic leg). These differences remained when normalizing for strength differences between the legs. Compared to controls, both the paretic and non-paretic VL showed pronounced reductions in ΔStO 2 during ramp and hold contractions equal to 20%, 40%, or 60% of the MVC ( p  < 0.05 vs. controls at all load levels)., Conclusions: These results indicate that oxygen desaturation in response to isometric muscle contractions is impaired in both the paretic and non-paretic leg muscle of stroke survivors compared to age-matched controls, and these differences are independent of differences in muscle strength.

Locomotor and balance disorders are major limitations for subjects with hemiparesis. The Timed Up and Go (TUG) test is a complex navigational task involving oriented walking and obstacle circumvention. We hypothesized that subjects with hemiparesis adopt a cautious gait during complex locomotor tasks. The primary aim was to compare spatio-temporal gait parameters, indicators of cautious gait, between the locomotor subtasks of the TUG (Go, Turn, Return) and a Straight-line walk in people with hemiparesis. Our secondary aim was to analyze the relationships between TUG performance and balance measures, compare spatio-temporal gait parameters between fallers and non-fallers, and identify the biomechanical determinants of TUG performance. Biomechanical parameters during the TUG and Straight-line walk were analyzed using a motion capture system. A repeated measures ANOVA and two stepwise ascending multiple regressions (with performance variables and biomechanical variables) were conducted. Gait speed, step length, and % single support phase (SSP) of the 29 participants were reduced during Turn compared to Go and Return and the Straight-line walk, and step width and % double support phase were increased. TUG performance was related to several balance measures. Turn performance (R 2 = 63%) and Turn trajectory deviation followed by % SSP on the paretic side and the vertical center of mass velocity during Go (R 2 = 71%) determined TUG performance time. People with hemiparesis adopt a cautious gait during complex navigation at the expense of performance.

Background: Acupuncture involving the limb region may be effective for stroke rehabilitation clinically, but the visualised and explanatory evidence is limited. Our objectives were to assess the specific effects of acupuncture for ischaemic stroke (IS) patients with hemiparesis and investigate its therapy-driven modification in functional connectivity., Methods: IS patients were randomly assigned (2:1) to receive 10 sessions of hand-foot 12 needles acupuncture (HA, n=30) or non-acupoint (NA) acupuncture (n=16), enrolling gender-matched and age-matched healthy controls (HCs, n=34). The clinical outcomes were the improved Fugl-Meyer Assessment scores including upper and lower extremity (ΔFM, ΔFM-UE, ΔFM-LE). The neuroimaging outcome was voxel-mirrored homotopic connectivity (VMHC). Static and dynamic functional connectivity (sFC, DFC) analyses were used to study the neuroplasticity reorganisation., Results: 46 ISs (mean(SD) age, 59.37 (11.36) years) and 34 HCs (mean(SD) age, 52.88 (9.69) years) were included in the per-protocol analysis of clinical and neuroimaging. In clinical, ΔFM scores were 5.00 in HA group and 2.50 in NA group, with a dual correlation between ΔFM and ΔVMHC (angular: r=0.696, p=0.000; cerebellum: r=-0.716, p=0.000) fitting the linear regression model (R 2 =0.828). In neuroimaging, ISs demonstrated decreased VMHC in bilateral postcentral gyrus and cerebellum (Gaussian random field, GRF corrected, voxel p<0.001, cluster p<0.05), which fitted the logistic regression model (AUC=0.8413, accuracy=0.7500). Following acupuncture, VMHC in bilateral superior frontal gyrus orbital part was increased with cerebro-cerebellar changes, involving higher sFC between ipsilesional superior frontal gyrus orbital part and the contralesional orbitofrontal cortex as well as cerebellum (GRF corrected, voxel p<0.001, cluster p<0.05). The coefficient of variation of VMHC was decreased in bilateral posterior cingulate gyrus (PPC) locally (GRF corrected, voxel p<0.001, cluster p<0.05), with integration states transforming into segregation states overall (p<0.05). There was no acupuncture-related adverse event., Conclusions: The randomised clinical and neuroimaging trial demonstrated acupuncture could promote the motor recovery and modified cerebro-cerebellar VMHC via bilateral static and dynamic reorganisations for IS patients with hemiparesis., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

After a stroke, antagonist muscle activation during agonist command impedes movement. This study compared measurements of antagonist muscle activation using surface bipolar EMG in the gastrocnemius medialis (GM) and high-density (HD) EMG in the GM and soleus (SO) during isometric submaximal and maximal dorsiflexion efforts, with knee flexed and extended, in 12 subjects with chronic hemiparesis. The coefficients of antagonist activation (CAN) of GM and SO were calculated according to the ratio of the RMS amplitude during dorsiflexion effort to the maximal agonist effort for the same muscle. Bipolar CAN (BipCAN) was compared to CAN from channel-specific (CsCAN) and overall (OvCAN) normalizations of HD-EMG. The location of the CAN centroid was explored in GM, and CAN was compared between the medial and lateral portions of SO. Between-EMG system differences in GM were observed in maximal efforts only, between BipCAN and CsCAN with lower values in BipCAN ( p < 0.001), and between BipCAN and OvCAN with lower values in OvCAN ( p < 0.05). The CAN centroid is located mid-height and medially in GM, while the CAN was similar in medial and lateral SO. In chronic hemiparesis, the estimates of GM hyperactivity differ between bipolar and HD-EMGs, with channel-specific and overall normalizations yielding, respectively, higher and lower CAN values than bipolar EMG. HD-EMG would be the way to develop personalized rehabilitation programs based on individual antagonist activations.

Tractography has become a widely available tool for the planning of neurosurgical operations as well as for neuroscientific research. The absence of patient interaction makes it easily applicable. However, it leaves uncertainty about the functional relevance of the identified bundles. We retrospectively analyzed the correlation of white matter markers with their clinical function in 24 right-handed patients who underwent first surgery for high-grade glioma. Morphological affection of the corticospinal tract (CST) and grade of paresis were assessed before surgery. Tractography was performed manually with MRTrix3 and automatically with TractSeg. Median and mean fractional anisotropy (FA) from manual tractography showed a significant correlation with CST affection (p = 0.008) and paresis (p = 0.015, p = 0.026). CST affection correlated further most with energy, and surface-volume ratio (p = 0.014) from radiomic analysis. Paresis correlated most with maximum 2D column diameter (p = 0.005), minor axis length (p = 0.006), and kurtosis (p = 0.008) from radiomic analysis. Streamline count yielded no significant correlations. In conclusion, mean or median FA can be used for the assessment of CST integrity in high-grade glioma. Also, several radiomic parameters are suited to describe tract integrity and may be used to quantitatively analyze white matter in the future., (© 2024. The Author(s).)

Background: How the weight-bearing asymmetry pattern and related maximum lateral weight-bearing capacity, physical functions, balance, and mobility involved in weight-bearing asymmetry and lesions are related to weight-bearing asymmetry in patients with early-onset stroke remains unclear., Objective: To investigate the difference between weight-bearing in the early phase after stroke categorized as symmetrical or nonsymmetrical regarding impairments, balance, walking, and independence, and any lesion location difference., Methods: This cross-sectional study included 46 persons with hemiparetic stroke within 3 weeks from onset undergoing inpatient rehabilitation and classified into symmetrical, paretic, and non-paretic groups. We performed posturographic, functional, mobility, and lesion location assessments on participants once the evaluation was possible., Results: The symmetrical, paretic, and non-paretic groups included 14, 11, and 21 patients, respectively. The non-paretic group had lesser mean % body weight in maximum lateral weight-bearing to the paretic direction (79% versus 55%, p < .001), motor function of the hip lower limb (64 versus 58, p = .003) per the Stroke Impairment Assessment Set, Trunk Impairment Scale (18 versus 15, p = .020), and Berg Balance Scale (42 versus 32, p = .047) than the paretic group with more lesions in the insula (55% versus 0%, p < .001) and parietal cortex (36% versus 0%, p = .009) than the non-paretic group., Conclusion: The non-paretic group had low dynamic balance, severe motor paresis, and trunk dysfunction. The paretic group had lesions in the insula or parietal cortex.

Background: Community ambulation involves complex walking adaptability tasks such as stepping over obstacles or taking long steps, which require adequate propulsion generation by the trailing leg. Individuals post-stroke often have an increased reliance on their trailing nonparetic leg and favor leading with their paretic leg, which can limit mobility. Ankle-foot-orthoses are prescribed to address common deficits post-stroke such as foot drop and ankle instability. However, it is not clear if walking with an ankle-foot-orthosis improves inter-limb propulsion symmetry during adaptability tasks. This study sought to examine this hypothesis., Methods: Individuals post-stroke (n = 9) that were previously prescribed a custom fabricated plantarflexion-stop articulated ankle-foot-orthosis participated. Participants performed steady-state walking and adaptability tasks overground with and without their orthosis. The adaptability tasks included obstacle crossing and long-step tasks, leading with both their paretic and nonparetic leg. Inter-limb propulsion symmetry was calculated using trailing limb ground-reaction-forces., Findings: During the obstacle crossing task, ankle-foot-orthosis use resulted in a significant improvement in inter-limb propulsion symmetry. The orthosis also improved ankle dorsiflexion during stance, reduced knee hyperextension, increased gastrocnemius muscle activity, and increased peak paretic leg ankle plantarflexor moment. In contrast, there were no differences in propulsion symmetry during steady-state walking and taking a long-step when using the orthosis., Interpretation: Plantarflexion-stop articulated ankle-foot-orthoses can improve propulsion symmetry during obstacle crossing tasks in individuals post-stroke, promoting paretic leg use and reduced reliance on the nonparetic leg., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: We aimed to quantify perioperative changes in diaphragmatic function and phrenic nerve conduction in patients undergoing routine thoracic surgery., Methods: A prospective observational study was performed in patients undergoing esophageal resection or pulmonary lobectomy. Examinations were carried out the day prior to surgery, 3 days and 10-14 days after surgery. Endpoints for diaphragmatic function included ultrasonographic measurements of diaphragmatic excursion and thickening fraction. Endpoints for phrenic nerve conduction included baseline-to-peak amplitude, peak-to-peak amplitude, and transmission delay. Measurements were assessed on both the surgical side and the non-surgical side of the thorax., Results: Forty patients were included in the study. Significant reductions in diaphragmatic excursion were seen on the surgical side of the thorax for all excursion measures (posterior part of the right hemidiaphragm, p < 0.001; hemidiaphragmatic top point, p < 0.001; change in intrathoracic area, p < 0.001). Significant changes were seen for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.041) on the surgical side. However, significant changes were also seen on the non-surgical side for all phrenic nerve measures (baseline-to-peak amplitude, p < 0.001; peak-to-peak amplitude, p < 0.001; transmission delay, p = 0.022). A postoperative reduction in posterior diaphragmatic excursion of more than 50% was significantly associated with postoperative pulmonary complications (coefficient: 2.69 (95% CI [1.38, 4.01], p < 0.001)., Conclusion: Thoracic surgery caused a significant unilateral reduction in diaphragmatic excursion on the surgical side of the thorax, which was accompanied by significant changes in phrenic nerve conduction. However, phrenic nerve conduction was also significantly affected on the non-surgical side to a lesser extent, which was not mirrored in diaphragmatic excursion. Our findings suggest that phrenic nerve paresis plays a role in postoperative diaphragmatic dysfunction, which may be a contributing factor in the pathogenesis of postoperative pulmonary complications., Clinical Trials Registration Number: NCT04507594., (© 2024. The Author(s).)

Secondary morphological and mechanical property changes in the muscle-tendon unit at the ankle joint are often observed in post-stroke individuals. These changes may alter the force generation capacity and affect daily activities such as locomotion. This work aimed to estimate subject-specific muscle-tendon parameters in individuals after stroke by solving the muscle redundancy problem using direct collocation optimal control methods based on experimental electromyography (EMG) signals and measured muscle fiber length. Subject-specific muscle-tendon parameters of the gastrocnemius, soleus, and tibialis anterior were estimated in seven post-stroke individuals and seven healthy controls. We found that the maximum isometric force, tendon stiffness and optimal fiber length in the post-stroke group were considerably lower than in the control group. We also computed the root mean square error between estimated and experimental values of muscle excitation and fiber length. The musculoskeletal model with estimated subject-specific muscle tendon parameters (from the muscle redundancy solver), yielded better muscle excitation and fiber length estimations than did scaled generic parameters. Our findings also showed that the muscle redundancy solver can estimate muscle-tendon parameters that produce force behavior in better accordance with the experimentally-measured value. These muscle-tendon parameters in the post-stroke individuals were physiologically meaningful and may shed light on treatment and/or rehabilitation planning.

Introduction: Action observation (AO) and motor imagery (MI) are considered functionally equivalent forms of motor representation related to movement execution (ME). Because of their characteristics, AO and MI have been proposed as techniques to facilitate the recovery of post-stroke hemiparesis in the upper extremities., Patients and Methods: An experimental, longitudinal, prospective, single-blinded design was undertaken. Eleven patients participated, and were randomly assigned to each study group. Both groups received 10 to 12 sessions of physical therapy. Five patients were assigned to the control treatment group, and six patients to the experimental treatment group (AO + MI). All were assessed before and after treatment for function, strength (newtons) and mobility (percentage) in the affected limb, as well as alpha desynchronisation (8-13 Hz) in the supplementary motor area, the premotor cortex and primary motor cortex while performing AO + MI tasks and action observation plus motor execution (AO + ME)., Results: The experimental group presented improvement in function and strength. A negative correlation was found between desynchronisation in the supplementary motor area and function, as well as a post-treatment increase in desynchronisation in the premotor cortex of the injured hemisphere in the experimental group only., Conclusions: An AO + MI-based intervention positively impacts recovery of the paretic upper extremity by stimulating the supplementary motor area, a cortex involved in movement preparation and learning. AO + MI therapy can be used as adjunctive treatment in patients with upper extremity paresis following chronic stroke.

Background: Movement smoothness is a potential kinematic biomarker of upper extremity (UE) movement quality and recovery after stroke; however, the measurement properties of available smoothness metrics have been poorly assessed in this group. We aimed to measure the reliability, responsiveness and construct validity of several smoothness metrics., Methods: This ancillary study of the REM-AVC trial included 31 participants with hemiparesis in the subacute phase of stroke (median time since stroke: 38 days). Assessments performed at inclusion (Day 0, D0) and at the end of a rehabilitation program (Day 30, D30) included the UE Fugl Meyer Assessment (UE-FMA), the Action Research Arm Test (ARAT), and 3D motion analysis of the UE during three reach-to-point movements at a self-selected speed to a target located in front at shoulder height and at 90% of arm length. Four smoothness metrics were computed: a frequency domain smoothness metric, spectral arc length metric (SPARC); and three temporal domain smoothness metrics (TDSM): log dimensionless jerk (LDLJ); number of submovements (nSUB); and normalized average rectified jerk (NARJ)., Results: At D30, large clinical and kinematic improvements were observed. Only SPARC and LDLJ had an excellent reliability (intra-class correlation > 0.9) and a low measurement error (coefficient of variation < 10%). SPARC was responsive to changes in movement straightness (r Spearman =0.64) and to a lesser extent to changes in movement duration (r Spearman =0.51) while TDSM were very responsive to changes in movement duration (r Spearman >0.8) and not to changes in movement straightness (non-significant correlations). Most construct validity hypotheses tested were verified except for TDSM with low correlations with clinical metrics at D0 (r Spearman <0.5), ensuing low predictive validity with clinical metrics at D30 (non-significant correlations)., Conclusions: Responsiveness and construct validity of TDSM were hindered by movement duration and/or noise-sensitivity. Based on the present results and concordant literature, we recommend using SPARC rather than TDSM in reaching movements of uncontrolled duration in individuals with spastic paresis after stroke., Trial Registration: NCT01383512, https://clinicaltrials.gov/ , June 27, 2011., (© 2024. The Author(s).)

Background: Reduced ankle quasi-joint stiffness affects propulsion in the paretic side of patients with hemiparesis, contributing to gait asymmetry. We investigated whether the use of an ankle-foot orthosis with dorsiflexion resistance to compensate for reduced stiffness would increase quasi-joint stiffness and spatiotemporal symmetry in patients with hemiparesis., Methods: Seventeen patients walked along a 7-m walkway in both ankle-foot orthosis with dorsiflexion resistance and control (i.e., ankle-foot orthosis) conditions. Dorsiflexion resistance by spring and cam was set to increase linearly from zero-degree ankle dorsiflexion. Gait data were analyzed using a three-dimensional motion analysis system., Findings: Ankle-foot orthosis with dorsiflexion resistance significantly increased the quasi-joint stiffness in the early and middle stance phase (P = 0.028 and 0.040). Furthermore, although ankle power generation in the ankle-foot orthosis with dorsiflexion resistance condition was significantly lower than in the control condition (P = 0.003), step length symmetry significantly increased in the ankle-foot orthosis with dorsiflexion resistance condition (P = 0.016). There was no significant difference in swing time ratio between conditions., Interpretation: Applying dorsiflexion resistance in the paretic stance phase increased quasi-joint stiffness but did not lead to an increase in ankle power generation. On the other hand, applying dorsiflexion resistance also resulted in a more symmetrical step length, even though the ankle joint power generation on the paretic side did not increase as expected. Future research should explore whether modifying the magnitude and timing of dorsiflexion resistance, considering the biomechanical characteristics of each patients' ankle joint during gait, enhances ankle joint power generation., Competing Interests: Declaration of competing interest Ryusuke Okamoto and Shino Inuzuka are employees of SEKISUI CHEMICAL CO., LTD. and Norihiro Morimoto is employer of SEKISUI TECHNO MOLDING CO., LTD., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Knowing how impaired manual dexterity and finger proprioception affect upper limb activity capacity is important for delineating targeted post-stroke interventions for upper limb recovery., Objectives: To investigate whether impaired manual dexterity and finger proprioception explain variance in post-stroke activity capacity, and whether they explain more variance than conventional clinical assessments of upper limb sensorimotor impairments., Methods: Activity capacity and hand sensorimotor impairments were assessed using clinical measures in N = 42 late subacute/chronic hemiparetic stroke patients. Dexterity was evaluated using the Dextrain Manipulandum to quantify accuracy of visuomotor finger force-tracking (N = 36), timing of rhythmic tapping (N = 36), and finger individuation (N = 24), as well as proprioception (N = 27). Stepwise multivariate and hierarchical linear regression models were used to identify impairments best explaining activity capacity., Results: Dexterity and proprioceptive components significantly increased the variance explained in activity capacity: (i) Box and Block Test was best explained by baseline tonic force during force-tracking and tapping frequency (adjusted R 2  = .51); (ii) Motor Activity Log was best explained by success rate in finger individuation (adjusted R 2  = .46); (iii) Action Research Arm Test was best explained by release of finger force and proprioceptive measures (improved reaction time related to use of proprioception; adjusted R 2  = .52); and (iv) Moberg Pick-Up test was best explained by proprioceptive function (adjusted R 2  = .18). Models excluding dexterity and proprioception variables explained up to 19% less variance., Conclusions: Manual dexterity and finger proprioception explain unique variance in activity capacity not captured by conventional impairment measures and should be assessed when considering the underlying causes of post-stroke activity capacity limitations.URL: https://www.clinicaltrials.gov. Unique identifier: NCT03934073., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: MT, MAM, and PGL have patented the method for multidimensional measurement of manual dexterity (WO2016184935A3). MT and PGL are founding members of start-up company Dextrain (started in 2021) who owns the commercial rights. MT now works for the start-up full-time. PGL, head of the scientific board, reports no financial gain in advising the company. CR is a member of the scientific board of the company but receives no financial benefits. The other authors report no financial interests or potential conflicts of interest.

Thanks to medical advances, life expectancy is increasing. With it comes an increased incidence of diseases, of which age is a risk factor. Stroke is among these diseases, and is one of the causes of long-term disability. The opportunity to treat these patients is via rehabilitation. A promising new technology that can enhance rehabilitation is virtual reality (VR). However, this technology is not widely used by elderly patients, and, moreover, the elderly often do not use modern technology at all. It therefore becomes a legitimate question whether elderly people will be able to use virtual reality in rehabilitation. This article presents a rehabilitation application dedicated to patients with upper limb paresis and unilateral spatial neglect (USN). The application was tested on a group of 60 individuals including 30 post-stroke patients with an average age of 72.83 years. The results of the conducted study include a self-assessment by the patients, the physiotherapist's evaluation, as well as the patients' performance of the exercise in VR. The study showed that elderly post-stroke patients are able to use virtual reality applications, but the ability to correctly and fully perform an exercise in VR depends on several factors. One of them is the ability to make logical contact ( p = 0.0001 < 0.05). However, the study presented here shows that the ability to use VR applications does not depend on age but on mental and physical condition, which gives hope that virtual reality applications can be used in post-stroke rehabilitation among patients of all ages.

Since the crossed control of sensitive-motor body functions by the contralateral cerebral hemispheres was recognized in the early 18th century, clinicians have been baffled by patients developing a motor deficit involving the extremities on the same side as an intracranial lesion. In the first third of the 20th century, three main hypotheses were proposed to explain this so-called ipsilateral or paradoxical hemiparesis: (1) the absence of decussation of the corticospinal tracts; (2) diaschisis, or blocking of the normal input to a brain region anatomically distant from the injured site; and (3) compression of the contralateral cerebral peduncle against the tentorial border, also known as the Kernohan-Woltman notch phenomenon. Here, we deal with the less widely known contributions of the Belgian neurosurgeon Léon Ectors, who included this paradoxical deficit within a neurological syndrome he considered highly specific for an early diagnosis of those meningiomas growing over the third frontal convolution. The present manuscript includes a systematic review of the cases of ipsilateral hemiparesis secondary to intracranial masses reported in ancient and modern scientific medical literature. We also address in-depth the physiopathological theories accounting for this syndrome and contrast them with Léon Ectors' observations., (© 2023. The Author(s) under exclusive licence to Belgian Neurological Society.)

Currently, strokes are on the 2 nd place on prevalence and mortality of the population, and an increase in the proportion of disabled people after cerebral stroke is noted. Disability is caused by motor deficiency of the paretic extremities, which impairs the patient's mobility, limits his participation in daily living, reduces the chances of returning to professional activity in 1/2 of patients after stroke. Due to this, the elimination of motor disorders and recovery of functional activity of the paretic extremities are the important aspects of post-stroke patients' medical rehabilitation., Objective: To study the dynamics and degrees of motor and functional disorders in patients with hemiparesis during the first 6 months after ischemic stroke under the impact of medical rehabilitation, including kinesiotherapy, physiotherapy and transcranial magnetic stimulation., Material and Methods: Motor disorders and functional limitations were assessed using validated scales (Fugl-Meyer, Medical Research Committee Scale, Modified Ashworth Scale of muscle spasticity, Modified Frenchay scale, Wolf Motor Function Test, Action Research Arm Test, Rivermead mobility index, Hauser ambulation index, Functional Independence Measurement). Diagnostic and therapeutic transcranial magnetic stimulation was performed using the «Neuro-MS/D» magnetic stimulator., Results: The dynamics of types and degrees of motor and functional disorders were evaluated in 113 patients with hemiparesis in the first 6 months after ischemic stroke. Severe disorders of the tone and strength characteristics of paretic muscles and limitation of movement in the joints of paretic extremities have been found in 2/3 of patients. The balance function (it is difficult to maintain a vertical position of the body) was impaired in 1/2 of patients. The correlations of electrophysiological indicators (diagnostic transcranial magnetic stimulation and surface electromyography) with clinical ones (degree of paresis, tone of paretic muscles, motor abilities and motor skills of the paretic hand, independence in daily living) have been determined. Positive impact of medical rehabilitation, including kinesiotherapy, physiotherapy and transcranial magnetic stimulation, on the strength of paretic muscles of the hand and leg, mobility of patients, walking function, activity of the paretic hand (transfer by the hands, manipulation of extremities' segments and objects) has been revealed. Electrophysiological investigation has shown that the functional activity of the paretic muscles increased., Conclusion: Severe motor and functional disorders, most pronounced in distal segments of the extremities (lack of movements in 14-26% of cases), are prevalent in the first six months after ischemic stroke in the carotid system. The regression of motor disorders leads to an enhancement of functional abilities (use of the paretic extremities for the realization of various motor actions) under the impact of rehabilitation.

Objectives: The main objective was to explore the effect of exoskeleton-assisted rehabilitation on quality of life in the subacute state of ischemic stroke., Background: Central upper extremity hemiparesis affects self-care, social participation, and quality of life. Exoskeleton devices serve as a therapeutic tool and an assessment tool that offers precise tracking of patient progress and evaluation of impairment., Methods: The trial was carried out from April 2022 to September 2023. Twenty-seven patients were randomly assigned to the intervention (14 participants; mean age 64.71 years; 5 women, 9 men) and control group (13 participants; mean age 64.69 years; 6 women, 7 men). Both groups received equal total therapy (10 to 12 sessions, 5 times a week). The intervention group received 30 minutes of Armea®Spring training combined with conventional rehabilitation. The control group was subjected to conventional rehabilitation., Results: In the comparison between groups, the experimental group achieved significant changes in quality of life, movement efficiency, and functional performance of the upper extremities., Conclusions: Armeo®Spring therapy combined with usual care led to significantly larger changes in health-related quality of life and upper extremity movement efficiency compared to conventional rehabilitation (Tab. 4, Fig. 3, Ref. 64.) Text in PDF www.elis.sk Keywords: stroke, hemiparesis, health-related quality of life, Armeo®Spring, movement efficiency, activities of daily living.

Background: Cerebral palsy is the most frequent condition affecting the central nervous system and causing large disability., Objective: To determine the impact of touch screen tablet upon fine motor functions in children with hemiparesis., Method: This was a randomized controlled trial involving 60 children, ranging in age from 5 to 7 years old, randomized into two groups: intervention or control group (30 children per group). Both groups were given 12 consecutive weeks of designed fine motor tasks. Additionally, for thirty minutes, the intervention group was given a fine motor exercise program on a touch screen tablet. Upper limb function, finger dexterity and pinch strength were measured pre and post the recommended treatment program using the quality of upper extremity skill test (QUEST), Nine-Hole Peg Test and Jamar hydraulic pinch gauge, respectively., Results: All outcome measures were equivalent between intervention groups at admission (P > 0.05). Significant improvements were found in all assessed variables within the two groups. Meanwhile, the intervention group had significantly higher improvements (P < 0.05) in finger dexterity, pinch strength, and upper limb function when compared with the control groups., Conclusion: Including a touch screen smart tablet application with a specially designed fine motor program is an effective method that helps children with U-CP perform more effectively with their fine motor skills.

Balance and functional impairment could occur due to the weakness of the gastrocsoleus muscles in acute stroke patients. This study was planned to determine the muscle architecture and its relationship to balance and functional strength functional ability in patients with acute stroke. A cross-sectional analysis of 22 stroke patients (68.59 ± 8.16) was performed in this study. Gastrocnemius muscle thickness and cross-sectional area were significantly greater on the non-paretic than on the paretic sides ( p  = 0.004, p  = 0.005, respectively). Partial correlation analysis showed that soleus muscle thickness and cross-sectional area was significantly correlated with Berg Balance Scale, Single Leg Stance Test, Five Times Sit to Stand Test and Tandem test results in the paretic side ( r  = 0.49-0.77, p  < 0.05). The gastrocnemius muscle thickness of the non-paretic side had a significant relationship with balance ( r  = 0.45-0.65, p  < 0.05). The muscle thickness and cross-sectional area of the soleus muscle on the paretic sides was significantly related with the functional strength and balance after stroke. It may be beneficial to develop clinical assessment and intervention programs focusing on distal plantar flexor muscle groups in order to improve the functional status and balance.

We examined effects of a visual search task (VST) in virtual reality (VR) with a moving background on spatial cognition and standing balance in left hemiparetic strokes. The VST with background deviation was allocated to Case A. In Case B, the VST without the deviation was performed. As a results, in Case A, the reaction time of VST was shortened in the paretic space and ability of weight-shift to the paretic side was improved. In conclusion, the VST in the VR with a spatial manipulation may improve spatial cognition and standing balance in left hemiparetic strokes.

Oxygen delivery and demand are reduced in the paretic leg post-stroke, reflecting decreased vascular function and reduced muscle quantity and quality. However, it is unknown how muscle oxygenation, the balance between muscle oxygen delivery and utilization, is altered in chronic stroke during and after occlusion-induced ischemia., Objectives: The objective was to determine muscle oxygen consumption rate, microvascular responsiveness and reactive hyperemia in the paretic and nonparetic legs during and after arterial occlusion post-stroke., Materials and Methods: Muscle oxygen saturation was measured with near-infrared spectroscopy on the vastus lateralis of each leg during 3-minute arterial occlusion and recovery (3 min). Muscle oxygen consumption was derived from the desaturation slope during ischemia, microvascular responsiveness was derived from the resaturation slope after ischemia and reactive hyperemia was derived from the area under the curve above baseline after ischemia., Results: Eleven subjects (91% male; 32.2±6.1 months post-stroke; age 62.9±13.6 years) with a hemiparetic gait pattern participated. There was no significant between-leg muscle oxygenation difference at rest (paretic: 64.9±16.6%; nonparetic: 70.6±15.6%, p = 0.13). Muscle oxygen consumption in the paretic leg (-0.53±0.24%/s) was significantly reduced compared to the nonparetic leg (-0.70±0.36%/s; p = 0.03). Microvascular responsiveness was significantly reduced in the paretic leg compared to the nonparetic leg (paretic: 4.6±1.8%/s; nonparetic: 5.7±1.6%/s, p = 0.04). Reactive hyperemia was not significantly different between legs (paretic:4384±2341%·s; nonparetic: 3040±2216%·s, p = 0.07)., Conclusion: Muscle oxygen consumption and microvascular responsiveness are impaired in the paretic compared to the nonparetic leg, suggesting both reduced skeletal muscle aerobic function and reduced ability to maximally perfuse muscle tissue., Competing Interests: Declarations of interest None., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This is a case series of six children with unilateral cerebral palsy and hemispheric encephaloclastic lesions who were evaluated for epilepsy surgery. Seizure onset was in the neonatal period in three children, at 17 months in two, and at 5 years in one. Their ictal and interictal electroencephalogram (EEG) abnormalities showed paradoxical lateralization to the incorrect/'normal' hemisphere or showed bilateral abnormalities. After cautious discussion regarding the discordant electroclinical profile and implications for outcome, they proceeded to a functional hemispherectomy (between ages 4-11y) with good outcomes (at 1-10y follow-up). Their clinical details, EEG findings, electrocorticography, neuroimaging, and histology are reported. Possible surgical candidacy should be evaluated early in children with refractory epilepsy, even those with complex profiles and discordant data from the different investigations. Contralateral or bilateral EEG abnormalities should not preclude consideration of hemispherectomy in children with refractory epilepsy, hemiparesis, and uniclastic lesions., (© 2021 Mac Keith Press.)

It is known that resistance exercise using one limb can affect motor function of both the exercised limb and the unexercised contralateral limb, a phenomenon termed cross-education. It has been suggested that cross-education has clinical implications, e.g. in rehabilitation for orthopaedic conditions or post-stroke paresis. Much of the research on the contralateral effect of unilateral intervention on motor output is based on voluntary exercise. This scoping review aimed to map the characteristics of current literature on the cross-education caused by three most frequently utilised peripheral neuromuscular stimulation modalities in this context: electrical stimulation, mechanical vibration and percutaneous needling, that may direct future research and translate to clinical practice. A systematic search of relevant databases (Ebsco, ProQuest, PubMed, Scopus, Web of Science) through to the end of 2020 was conducted following the PRISMA Extension for Scoping Review. Empirical studies on human participants that applied a unilateral peripheral neuromuscular stimulation and assessed neuromuscular function of the stimulated and/or the unstimulated side were selected. By reading the full text, the demographic characteristics, context, design, methods and major findings of the studies were synthesised. The results found that 83 studies were eligible for the review, with the majority (53) utilised electrical stimulation whilst those applied vibration (18) or needling (12) were emerging. Although the contralateral effects appeared to be robust, only 31 studies claimed to be in the context of cross-education, and 25 investigated on clinical patients. The underlying mechanism for the contralateral effects induced by unilateral peripheral stimulation remains unclear. The findings suggest a need to enhance the awareness of cross-education caused by peripheral stimulation, to help improve the translation of theoretical concepts to clinical practice, and aid in developing well-designed clinical trials to determine the efficacy of cross-education therapies., Competing Interests: The authors have declared that no competing interests exist.

Proprioceptive deficit is one of the common sensory impairments following stroke and has a negative impact on motor performance. However, evidence-based training procedures and cost-efficient training setups for patients with poststroke are still limited. We compared the effects of proprioceptive training versus nonspecific sensory stimulation on upper limb proprioception and motor function rehabilitation. In this multicenter, single-blind, randomized controlled trial, 40 participants with poststroke hemiparesis were enrolled from 3 hospitals in China. Participants were assigned randomly to receive proprioceptive training involving passive and active movements with visual feedback (proprioceptive training group [PG]; n = 20) or nonspecific sensory stimulation (control group [CG]; n = 20) 20 times in four weeks. Each session lasted 30 minutes. A clinical assessor blinded to group assignment evaluated patients before and after the intervention. The primary outcome was the change in the motor subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-M). Secondary outcomes were changes in box and block test (BBT), thumb localization test (TLT), the sensory subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-S), and Barthel Index (BI). The results showed that the mean change scores of FMA-UE were significantly greater in the PG than in the CG ( p = 0.010 for FMA-UE-M, p = 0.033 for FMA-UE-S). The PG group was improved significantly in TLT ( p = 0.010) and BBT ( p = 0.027), while there was no significant improvement in TLT ( p = 0.083) and BBT ( p = 0.107) for the CG group. The results showed that proprioceptive training was effective in improving proprioception and motor function of the upper extremity in patients with poststroke. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR2000037808)., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Jieying He et al.)

Objective: To determine the accuracy of an algorithm, using clinical measures only, on a sample of persons with first-ever stroke in the United States (US). It was hypothesized that algorithm accuracy would fall in a range of 70%-80%., Design: Secondary analysis of prospective, observational, longitudinal cohort; 2 assessments were done: (1) within 48 hours to 1 week poststroke and (2) at 12 weeks poststroke., Setting: Recruited from a large acute care hospital and followed over the first 6 months after stroke., Participants: Adults with first-ever stroke (N=49) with paresis of the upper limb (UL) at ≤48 hours who could follow 2-step commands and were expected to return to independent living at 6 months., Intervention: Not applicable., Main Outcome Measures: The overall accuracy of the algorithm with clinical measures was quantified by comparing predicted (expected) and actual (observed) categories using a correct classification rate., Results: The overall accuracy (61%) and weighted κ (62%) were significant. Sensitivity was high for the Excellent (95%) and Poor (81%) algorithm categories. Specificity was high for the Good (82%), Limited (98%), and Poor (95%) categories. Positive predictive value (PPV) was high for Poor (82%) and negative predictive value (NPV) was high for all categories. No differences in participant characteristics were found between those with accurate or inaccurate predictions., Conclusions: The results of the present study found that use of an algorithm with clinical measures only is better than chance alone (chance=25% for each of the 4 categories) at predicting a category of UL capacity at 3 months post troke. The moderate to high values of sensitivity, specificity, PPV, and NPV demonstrates some clinical utility of the algorithm within health care settings in the US., (Copyright © 2021 The American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

In neurotypical individuals, arm choice in reaching movements depends on expected biomechanical effort, expected success, and a handedness bias. Following a stroke, does arm choice change to account for the decreased motor performance, or does it follow a preinjury habitual preference pattern? Participants with mild-to-moderate chronic stroke who were right-handed before stroke performed reaching movements in both spontaneous and forced-choice blocks, under no-time, medium-time, and fast-time constraint conditions designed to modulate reaching success. Mixed-effects logistic regression models of arm choice revealed that expected effort predicted choices. However, expected success only strongly predicted choice in left-hemiparetic individuals. In addition, reaction times decreased in left-hemiparetic individuals between the no-time and the fast-time constraint conditions but showed no changes in right-hemiparetic individuals. Finally, arm choice in the no-time constraint condition correlated with a clinical measure of spontaneous arm use for right-, but not for left-hemiparetic individuals. Our results are consistent with the view that right-hemiparetic individuals show a habitual pattern of arm choice for reaching movements relatively independent of failures. In contrast, left-hemiparetic individuals appear to choose their paretic left arm more optimally: that is, if a movement with the paretic arm is predicted to be not successful in the upcoming movement, the nonparetic right arm is chosen instead. NEW & NOTEWORTHY Although we are seldom aware of it, we constantly make decisions to use one arm or the other in daily activities. Here, we studied whether these decisions change following stroke. Our results show that effort, success, and side of lesion determine arm choice in a reaching task: whereas left-paretic individuals modified their arm choice in response to failures in reaching the target, right-paretic individuals showed a pattern of choice independent of failures.

Bistable motoneurons of the spinal cord exhibit warmth-activated plateau potential driven by Na + and triggered by a brief excitation. The thermoregulating molecular mechanisms of bistability and their role in motor functions remain unknown. Here, we identify thermosensitive Na + -permeable Trpm5 channels as the main molecular players for bistability in mouse motoneurons. Pharmacological, genetic or computational inhibition of Trpm5 occlude bistable-related properties (slow afterdepolarization, windup, plateau potentials) and reduce spinal locomotor outputs while central pattern generators for locomotion operate normally. At cellular level, Trpm5 is activated by a ryanodine-mediated Ca 2+ release and turned off by Ca 2+ reuptake through the sarco/endoplasmic reticulum Ca 2+ -ATPase (SERCA) pump. Mice in which Trpm5 is genetically silenced in most lumbar motoneurons develop hindlimb paresis and show difficulties in executing high-demanding locomotor tasks. Overall, by encoding bistability in motoneurons, Trpm5 appears indispensable for producing a postural tone in hindlimbs and amplifying the locomotor output., (© 2021. The Author(s).)