Abstract The aims of this study were first to further assess the role of the 3D trunk angular rotations as part of the kinematic chain for seated-reaching movements within arm's length in a large 3D ...workspace in healthy subjects and second, to assess if these degrees of freedom participate in the compensatory strategy in hemiparetic patients. Ten healthy subjects, eight patients with right, and eight patients with left hemiparesis following stroke were included. They performed seated reaching movements at a comfortable speed to nine targets positioned in a large 3D workspace within arm's length. An electromagnetic system was used to record kinematics of the trunk and hand. Trunk flexion, lateral flexion and torsion were analyzed as a function of target direction, distance and height. In both healthy subjects and patients, all three trunk rotations participated in the reaching movement (except for near targets in healthy subjects). Trunk flexion was greater in patients but followed a similar pattern to healthy subjects. Trunk torsion was more influenced by target distance in healthy subjects while in patients it was greatly influenced by direction. Trunk lateral flexion was similar between groups. Comparing the two patient groups, there was greater flexion to the external targets in the RHD group and different strategies in the use of torsion between groups. 3D trunk rotations thus seem to be tuned to the distance and direction of the target in the workspace in both healthy subjects and stroke patients for reaching movements within arm's length.
Following stroke, control of both the contralesional (paretic) and ipsilesional (less affected) arms is altered. The purpose of this study was to analyse the consequences of stroke on joint rotations ...of both shoulder girdles, that is, glenohumeral (GH) and scapula motion. Because of hemispheric specialization, we hypothesized that changes would relate to the side of hemisphere damage. Nine stroke patients with left, and 9 with right hemisphere damage (LHD and RHD) and 9 healthy subjects were included. Reaching movements to targets positioned close, far and high in three directions were recorded using an electromagnetic system. Initial and final postures of the scapula, GH and elbow joint were evaluated. Inter-joint rotations throughout the movements were analysed using principal component analysis (PCA). The main finding was that initial and final postures of the contralesional and ipsilesional shoulders differed depending on the side of brain lesion. On the contralesional side, there was less scapula protraction and GH lateral rotation for both groups. Scapula tilt was less anterior in LHD patients, and GH elevation was greater in RHD patients. On the ipsilesional side, GH lateral rotation was reduced in both groups, and scapula protraction was reduced only for LHD patients. PCA confirmed that postures of both shoulders of the LHD group were substantially different to the healthy subjects, while only the contralesional arm of the RHD subjects differed. These results add to existing knowledge of hemispheric specialization, suggesting that the left hemisphere plays a greater role in bilateral joint postures than the right hemisphere.
Single-cell RNA sequencing has generated catalogs of transcriptionally defined neuronal subtypes of the brain. However, the cellular processes that contribute to neuronal subtype specification and ...transcriptional heterogeneity remain unclear. By comparing the gene expression profiles of single layer 6 corticothalamic neurons in somatosensory cortex, we show that transcriptional subtypes primarily reflect axonal projection pattern, laminar position within the cortex, and neuronal activity state. Pseudotemporal ordering of 1,023 cellular responses to sensory manipulation demonstrates that changes in expression of activity-induced genes both reinforced cell-type identity and contributed to increased transcriptional heterogeneity within each cell type. This is due to cell-type biased choices of transcriptional states following manipulation of neuronal activity. These results reveal that axonal projection pattern, laminar position, and activity state define significant axes of variation that contribute both to the transcriptional identity of individual neurons and to the transcriptional heterogeneity within each neuronal subtype.
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•Transcriptional heterogeneity reflects axonal target, position, and activity state•Altering sensory input increases transcriptional heterogeneity within neural types•Ordering of neuron responses reveals cell-type biased, not specific, trajectories•Biased activity-induced responses enhance differences among neural subtypes
Chevée et al. find that sources of transcriptional heterogeneity defining cortical projection neurons include axonal projection pattern, laminar position, and activity state. Altering activity state through sensory manipulation increased cell-to-cell variation within cell types and enhanced distinctions between cell types.
This study aimed to identify and qualify grasp-types used by patients with stroke and determine the clinical parameters that could explain the use of each grasp. Thirty-eight patients with chronic ...stroke-related hemiparesis and a range of motor and functional capacities (17 females and 21 males, aged 25-78), and 10 healthy subjects were included. Four objects were used (tissue packet, teaspoon, bottle and tennis ball). Participants were instructed to "grasp the object as if you are going to use it". Three trials were video-recorded for each object. A total of 456 grasps were analysed and rated using a custom-designed Functional Grasp Scale. Eight grasp-types were identified from the analysis: healthy subjects used Multi-pulpar, Pluri-digital, Lateral-pinch and Palmar grasps (Standard Grasps). Patients used the same grasps with in addition Digito-palmar, Raking, Ulnar and Interdigital grasps (Alternative Grasps). Only patients with a moderate or relatively good functional ability used Standard grasps. The correlation and regression analyses showed this was conditioned by sufficient finger and elbow extensor strength (Pluri-digital grasp); thumb extensor and wrist flexor strength (Lateral pinch) or in forearm supinator strength (Palmar grasp). By contrast, the patients who had severe impairment used Alternative grasps that did not involve the thumb. These strategies likely compensate specific impairments. Regression and correlation analyses suggested that weakness had a greater influence over grasp strategy than spasticity. This would imply that treatment should focus on improving hand strength and control although reducing spasticity may be useful in some cases.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
While a large number of robotic exoskeletons have been designed by research teams for rehabilitation, it remains rather difficult to analyse their ability to finely interact with a human limb: no ...performance indicators or general methodology to characterize this capacity really exist. This is particularly regretful at a time when robotics are becoming a recognized rehabilitation method and when complex problems such as 3-D movement rehabilitation and joint rotation coordination are being addressed. The aim of this paper is to propose a general methodology to evaluate, through a reduced set of simple indicators, the ability of an exoskeleton to interact finely and in a controlled way with a human. The method involves measurement and recording of positions and forces during 3-D point to point tasks. It is applied to a 4 degrees-of-freedom limb exoskeleton by way of example.
The type VI secretion system (T6SS) has emerged as a critical virulence factor for the group of closely related Burkholderia spp. that includes Burkholderia pseudomallei, B. mallei, and B. ...thailandensis. While the genomes of these bacteria, referred to as the Bptm group, appear to encode several T6SSs, we and others have shown that one of these, type VI secretion system 5 (T6SS-5), is required for virulence in mammalian infection models. Despite its pivotal role in the pathogenesis of the Bptm group, the effector repertoire of T6SS-5 has remained elusive. Here we used quantitative mass spectrometry to compare the secretome of wild-type B. thailandensis to that of a mutant harboring a nonfunctional T6SS-5. This analysis identified VgrG-5 as a novel secreted protein whose export depends on T6SS-5 function. Bioinformatics analysis revealed that VgrG-5 is a specialized VgrG protein that harbors a C-terminal domain (CTD) conserved among Bptm group species. We found that a vgrG-5 ΔCTD mutant is avirulent in mice and is unable to stimulate the fusion of host cells, a hallmark of the Bptm group previously shown to require T6SS-5 function. The singularity of VgrG-5 as a detected T6SS-5 substrate, taken together with the essentiality of its CTD for virulence, suggests that the protein is critical for the effector activity of T6SS-5. Intriguingly, we show that unlike the bacterial-cell-targeting T6SSs characterized so far, T6SS-5 localizes to the bacterial cell pole. We propose a model whereby the CTD of VgrG-5-, propelled by T6SS-5-, plays a key role in inducing membrane fusion, either by the recruitment of other factors or by direct participation.
Abstract Stiff knee gait (SKG) is common in hemiplegic patients. The main focus of treatment is rectus femoris (RF) spasticity. The aims of this study were to evaluate the effect of botulinum toxin ...injection (BTI) in the RF muscle on peak knee flexion during swing phase and its quantitative and functional impact on gait. We also wished to evaluate the correlation between the effects of nerve block and BTI on peak knee flexion. 10 adult hemiplegic subjects (> 6 months post stroke or traumatic brain injury) with SKG and inappropriate RF EMG activity during mid-swing phase were included. 3D gait analysis, clinical and functional assessments (Timed Up and Go test, 10 m walk test, 6 min walk test and the time taken to ascend and descend a flight of stairs) were performed initially, 30 min after anaesthetic block of the RF nerve and one month post BTI. After BTI, there was a significant increase in knee flexion (8° average) and a tendency towards improvement in gait and functional parameters. The effect of the nerve block on peak knee flexion was significantly correlated with the effect of BTI (11° average increase in peak knee flexion after nerve block). We challenge the relevance of RF nerve blocks in this population when EMG and kinematic data are available. Our results indicate that BTI is an effective treatment for SKG in adult hemiplegic subjects, with a significant increase in peak knee flexion, no reduction in hip flexion and a tendency towards functional improvements.
Background. Poor control of reaching in spastic hemiparetic patients could be because of a combination of poor individuation of joints, weakness, spasticity, and/or sensory loss. Objective. To assess ...the effect of botulinum toxin injections (BTIs) on spasticity, upper-limb function, and kinematics of reaching movements in patients with spastic hemiparesis caused by brain injury. Methods. Fifteen patients with spastic hemiparesis and 9 healthy controls were included in this single-site, open-labeled study. The trajectories of reaching movements were recorded, and kinematic variables were computed. A clinical evaluation included the Motor Activity Log, the Action Research Arm Test (ARAT), and the Box and Block Test (BBT). Patients were assessed before (M0), 1 month after a first (M1), and 1 month after a second BTI (M4, at 4 months) in proximal and distal muscles. Results. Significant differences were found between hemiparetic patients and healthy participants for all kinematic parameters. All parameters tended to improve after BTI. This effect was significant for velocity and smoothness. Functional scores also tended to improve. Improvements were greater at M4 than at M1, although the differences were not significant. Conclusions. Kinematic parameters improved following BTI, without significant changes in clinical outcomes such as ARAT and BBT. The decrease in spasticity alone does not seem to explain the results, which may be a result of adaptation to the decrease in hypertonicity leading to increased use of the arm and possibly an increase in antagonist muscle strength.
•Interactive gaming induced similar changes in elbow extension as conventional therapy.•Physiotherapist-supervised interactive gaming did not enhance forward trunk movement.•Arm but not trunk ...acceleration increased across gaming sessions.•The number of sessions may have been too low to induce clinically important changes.
Commercial gaming systems are increasingly being used for stroke rehabilitation; however, their effect on upper-limb recovery versus compensation is unknown.
We aimed to compare the effect of upper-limb rehabilitation using interactive gaming (Nintendo Wii) with dose-matched conventional therapy on elbow extension (recovery) and forward trunk motion (compensation) in individuals with chronic stroke. Secondary aims were to compare the effect on (1) clinical tests of impairment and activity, pain and effort, and (2) trajectory kinematics. We also explored arm and trunk motion (acceleration) during Wii sessions to understand how participants performed movements during Wii gaming.
This single-centre, randomized controlled trial compared 12 hourly sessions over 4 weeks of upper-limb Wii therapy to conventional therapy. Outcomes were evaluated at baseline and 4 weeks. The change in elbow extension and trunk motion during a reaching task was evaluated by electromagnetic sensors. Secondary outcomes were change in Fugl-Meyer assessment, Box and Block test, Action Research Arm Test, Motor Activity Log, and Stroke Impact Scale scores. Arm and trunk acceleration during Wii therapy was evaluated by using inertial sensors. A healthy control group was included for reference data.
Nineteen participants completed Wii therapy and 21 conventional therapy (mean SD time post-stroke 66.4 57.2 months). The intervention and control groups did not differ in mean change in elbow extension angle (Wii: +4.5°, 95% confidence interval CI 0.1; 9.1; conventional therapy: +6.4°, 95%CI 0.6; 12.2) and forward trunk position (Wii: -3.3 cm, 95%CI -6.2;-0.4; conventional therapy: -4.1 cm, 95%CI -6.6; -1.6) (effect size: elbow, d = 0.16, p = 0.61; trunk, d = 0.13, p = 0.65). Clinical scores improved similarly but to a small extent in both groups. The amount of arm but not trunk acceleration produced during Wii sessions increased with training.
Supervised upper-limb gaming therapy induced similar recovery of elbow extension as conventional therapy and did not enhance the development of compensatory forward trunk movement in individuals with chronic stroke. More sessions may be necessary to induce greater improvements.
NCT01806883
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.
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).
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
=0.64) and to a lesser extent to changes in movement duration (r
=0.51) while TDSM were very responsive to changes in movement duration (r
>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
<0.5), ensuing low predictive validity with clinical metrics at D30 (non-significant correlations).
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.
NCT01383512, https://clinicaltrials.gov/ , June 27, 2011.
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