A Longitudinal Electromyography Study of Complex Movements in Poststroke Therapy. 1: Heterogeneous Changes Despite Consistent Improvements in Clinical Assessments

Poststroke weakness on the more-affected side may arise from reduced corticospinal drive, disuse muscle atrophy, spasticity, and abnormal coordination. This study investigated changes in muscle activation patterns to understand therapy-induced improvements in motor-function in chronic stroke compared to clinical assessments and to identify the effect of motor-function level on muscle activation changes. Electromyography (EMG) was recorded from five upper limb muscles on the more-affected side of 24 patients during early and late therapy sessions of an intensive 14-day program of Wii-based Movement Therapy (WMT) and for a subset of 13 patients at 6-month follow-up. Patients were classified according to residual voluntary motor capacity with low, moderate, or high motor-function levels. The area under the curve was calculated from EMG amplitude and movement duration. Clinical assessments of upper limb motor-function pre- and post-therapy included the Wolf Motor Function Test, Fugl-Meyer Assessment and Motor Activity Log Quality of Movement scale. Clinical assessments improved over time (p < 0.01) with an effect of motor-function level (p < 0.001). The pattern of EMG change by late therapy was complex and variable, with differences between patients with low compared to moderate or high motor-function levels. The area under the curve (p = 0.028) and peak amplitude (p = 0.043) during Wii-tennis backhand increased for patients with low motor-function, whereas EMG decreased for patients with moderate and high motor-function levels. The reductions included movement duration during Wii-golf (p = 0.048, moderate; p = 0.026, high) and Wii-tennis backhand (p = 0.046, moderate; p = 0.023, high) and forehand (p = 0.009, high) and the area under the curve during Wii-golf (p = 0.018, moderate) and Wii-baseball (p = 0.036, moderate). For the pooled data over time, there was an effect of motor-function (p = 0.016) and an interaction between time and motor-function (p = 0.009) for Wii-golf movement duration. Wii-baseball movement duration decreased as a function of time (p = 0.022). There was an effect on Wii-tennis forehand duration for time (p = 0.002), an interaction of time and motor-function (p = 0.005) and an effect of motor-function level on the area under the curve (p = 0.034) for Wii-golf. This study demonstrated different patterns of EMG changes according to residual voluntary motor-function levels, despite heterogeneity within each level that was not evident following clinical assessments alone. Thus, rehabilitation efficacy might be underestimated by analyses of pooled data

Targeted upper-limb Wii-based movement therapy also improves lower-limb muscle activation and functional movement in chronic stroke

Post-stroke hemiparesis may manifest as asymmetric gait, poor balance, and inefficient movement patterns. We investigated improvements in lower-limb muscle activation and function during Wii-based Movement Therapy (WMT), a rehabilitation program specifically targeting upper-limb motorfunction

Comparison of three tools to measure improvements in upper-limb function with poststroke therapy

Background. Functional ability is regularly monitored poststroke to assess improvement and the efficacy of clinical trials. The balance between implementation times and sensitivity has led to multidomain tools that aim to assess upper-limb function comprehensively. Objective. This study implemented 3 common multidomain tools to investigate their suitability across a broad spectrum of movement ability after stroke. Methods. Forty-nine hemiparetic patients (18 females), aged 22 to 83 years and 24.7 ± 39.2 months poststroke, were assessed before and after a 14-day upper-limb rehabilitation program of Wii-based Movement Therapy. Assessments included the upper-limb motor subscale of the Fugl-Meyer Assessment (F-M), the Wolf Motor Function Test (WMFT), and the Motor Assessment Scale (MAS) upper-limb sections 6 to 8. The MAS was analyzed both with and without the hierarchical system. Patients were stratified with low, moderate, or high motor-function. Results. Upper-limb function improved significantly for the pooled cohort for all assessments (P < .001), although ceiling effects were evident for the F-M, floor effects for the WMFT, and both floor and ceiling effects for MAS. When analyzed by stratified subgroup these improvements were significant for all groups with the F-M, for the moderate and high motor-function groups with both the WMFT and the MAS scored without hierarchical system, but only for the high motor-function group with the hierarchically scored MAS. Conclusion. These results suggest that no single test is suitable for measuring function and improvement across the spectrum of poststroke upper-limb dysfunction and that assessment tool selection should be based on the level of residual motor-function of individual patients

Revisiting poststroke upper limb stratification : Resilience in a larger cohort

Background Upper limb (UL) impairment in stroke survivors is both multifactorial and heterogeneous. Stratification of motor function helps identify the most sensitive and appropriate assessments, which in turn aids the design of effective and individualized rehabilitation strategies. We previously developed a stratification method combining the Grooved Pegboard Test (GPT) and Box and Block Test (BBT) to stratify poststroke UL motor function. Objective To investigate the resilience of the stratification method in a larger cohort and establish its appropriateness for clinical practice by investigating limitations of the GPT completion time. Methods Post hoc analysis of motor function for 96 community-dwelling participants with stroke (n = 68 male, 28 female, age 60.8 ± 14 years, 24.4 ± 36.6 months poststroke) was performed using the Wolf Motor Function Test (WMFT), Fugl-Meyer Assessment (F-M), BBT, and GPT. Hypothesis-free and hypothesis-based hierarchical cluster analyses were conducted to determine the resilience of the stratification method. Results The hypothesis-based analysis identified the same functional groupings as the hypothesis-free analysis: low (n = 32), moderate (n = 26), and high motor function (n = 38), with 3 exceptions. Thirty-three of the 38 participants with fine manual dexterity completed the GPT in ≤5 minutes. The remaining 5 participants took 6 to 25 minutes to place all 25 pegs but used alternative movement strategies to complete the test. The GPT time restriction changed the functional profile of the moderate and high motor function groups leading to more misclassifications. Conclusion The stratification method unambiguously classifies participants by UL motor function. While the inclusion of a 5-minute cutoff time for the GPT is preferred for clinical practice, it is not recommended for stratification purposes

A Longitudinal Electromyography Study of Complex Movements in Poststroke Therapy. 2: Changes in Coordinated Muscle Activation

Fine motor control is achieved through the coordinated activation of groups of muscles, or “muscle synergies.” Muscle synergies change after stroke as a consequence of the motor deficit. We investigated the pattern and longitudinal changes in upper limb muscle synergies during therapy in a largely unconstrained movement in patients with a broad spectrum of poststroke residual voluntary motor capacity. Electromyography (EMG) was recorded using wireless telemetry from 6 muscles acting on the more-affected upper body in 24 stroke patients at early and late therapy during formal Wii-based Movement Therapy (WMT) sessions, and in a subset of 13 patients at 6-month follow-up. Patients were classified with low, moderate, or high motor-function. The Wii-baseball swing was analyzed using a non-negative matrix factorization (NMF) algorithm to extract muscle synergies from EMG recordings based on the temporal activation of each synergy and the contribution of each muscle to a synergy. Motor-function was clinically assessed immediately pre- and post-therapy and at 6-month follow-up using the Wolf Motor Function Test, upper limb motor Fugl-Meyer Assessment, and Motor Activity Log Quality of Movement scale. Clinical assessments and game performance demonstrated improved motor-function for all patients at post-therapy (p &lt; 0.01), and these improvements were sustained at 6-month follow-up (p &gt; 0.05). NMF analysis revealed fewer muscle synergies (mean ± SE) for patients with low motor-function (3.38 ± 0.2) than those with high motor-function (4.00 ± 0.3) at early therapy (p = 0.036) with an association trend between the number of synergies and the level of motor-function. By late therapy, there was no significant change between groups, although there was a pattern of increase for those with low motor-function over time. The variability accounted for demonstrated differences with motor-function level (p &lt; 0.05) but not time. Cluster analysis of the pooled synergies highlighted the therapy-induced change in muscle activation. Muscle synergies could be identified for all patients during therapy activities. These results show less complexity and more co-activation in the muscle activation for patients with low motor-function as a higher number of muscle synergies reflects greater movement complexity and task-related phasic muscle activation. The increased number of synergies and changes within synergies by late-therapy suggests improved motor control and movement quality with more distinct phases of movement

Stroke: Occlusion and Flow

Exhibition:Why are we both attracted and repulsed by Blood?During our curatorial journey, we quickly discovered that blood is polarising. While it is crucial to keeping us alive – filling seven percent of our body – blood still commonly makes us feel uncomfortable. It is this fascinating positive/negative dichotomy that is fundamental to the narrative we explored. Blood is a powerful cultural symbol of positive and negative associations, one that represents life and death, health and sickness, and attraction and repulsion.STROKE: OCCLUSION AND FLOWArtist John McGhee3D Virtual Reality Experience - Oculus Rift HeadsetThis series of virtual reality experiences focus on immersing the user in actual clinical stroke data. The imagery displayed on the Oculus Rift headset is a direct visualisation of 3D clinical Magnetic Resonance Imaging (MRI) and Computed Tomography CT data. The datasets were acquired from stroke survivors with a history of cardiovascular disease and high cholesterol. When wearing the headset, users are able to move along the arteries in the brain by means of a video game controller. They can follow the path of the red blood cells from the aorta to the site of the stroke. In this series, three of the most common types of stroke were visualised, including ischaemic strokes caused by vessel occlusion, thromboembolism, and a haemorrhagic stroke caused by aneurysm rupture.McGhee has created visual imagery drawn from the cinematic, directly influenced by the feature film ‘Fantastic Voyage’. The aesthetic experience uses 3D computer generated imagery (CGI) atmospherics and augmented components such as arterial plaque on the blood vessel walls and red blood cells. All of these visual features increase the feeling of embodiment

Two Common Tests of Dexterity Can Stratify Upper-Limb Motor Function After Stroke

Background. Neurological deficits after a stroke are commonly classified according to motor function for clinical decision making regarding discharge and rehabilitation. Participants in clinical stroke studies are also stratified by motor function to avoid a sampling bias. Objective. This post hoc analysis examined a suite of upper limb functional assessment tools to test the hypothesis that motor function of survivors of stroke can be stratified using 2 simple tests of manual dexterity despite the heterogeneity of the population. Methods. The functional ability of the more affected hand and arm was assessed for 67 hemiparetic patients, aged 18 to 83 years (mean ± standard deviation, 59.8 ± 14.0 years), at 1 to 264 months after a stroke (23.6 ± 39.6 months) using the Wolf Motor Function Test (WMFT), upper limb motor Fugl-Meyer Assessment (F-M), Box and Block Test (BBT), grooved pegboard test, and wrist range of motion. We tested the strength of our proposed stratification scheme with a hypothesis-driven hierarchical cluster analysis using standardized raw scores and dichotomous BBT and grooved pegboard test values. Results. The most salient discriminator between low and higher motor function was the ability to move > 1 block on the BBT. Within the higher function group, the ability to place all 25 pegs on the grooved pegboard test discriminated between moderate and high motor function. The derived scheme was congruent with clinical observations. The WMFT timed tasks, F-M scores, and range of motion did not discriminate functional groups. Conclusions. Two simple unambiguous and objective tests of gross (BBT) and fine (grooved pegboard test) manual dexterity discriminated 3 groups of motor function ability for a heterogeneous group of patients after stroke

A Longitudinal Electromyography Study of Complex Movements in Poststroke Therapy. 1: Heterogeneous Changes Despite Consistent Improvements in Clinical Assessments

Poststroke weakness on the more-affected side may arise from reduced corticospinal drive, disuse muscle atrophy, spasticity, and abnormal coordination. This study investigated changes in muscle activation patterns to understand therapy-induced improvements in motor-function in chronic stroke compared to clinical assessments and to identify the effect of motor-function level on muscle activation changes. Electromyography (EMG) was recorded from five upper limb muscles on the more-affected side of 24 patients during early and late therapy sessions of an intensive 14-day program of Wii-based Movement Therapy (WMT) and for a subset of 13 patients at 6-month follow-up. Patients were classified according to residual voluntary motor capacity with low, moderate, or high motor-function levels. The area under the curve was calculated from EMG amplitude and movement duration. Clinical assessments of upper limb motor-function pre- and post-therapy included the Wolf Motor Function Test, Fugl-Meyer Assessment and Motor Activity Log Quality of Movement scale. Clinical assessments improved over time (p < 0.01) with an effect of motor-function level (p < 0.001). The pattern of EMG change by late therapy was complex and variable, with differences between patients with low compared to moderate or high motor-function levels. The area under the curve (p = 0.028) and peak amplitude (p = 0.043) during Wii-tennis backhand increased for patients with low motor-function, whereas EMG decreased for patients with moderate and high motor-function levels. The reductions included movement duration during Wii-golf (p = 0.048, moderate; p = 0.026, high) and Wii-tennis backhand (p = 0.046, moderate; p = 0.023, high) and forehand (p = 0.009, high) and the area under the curve during Wii-golf (p = 0.018, moderate) and Wii-baseball (p = 0.036, moderate). For the pooled data over time, there was an effect of motor-function (p = 0.016) and an interaction between time and motor-function (p = 0.009) for Wii-golf movement duration. Wii-baseball movement duration decreased as a function of time (p = 0.022). There was an effect on Wii-tennis forehand duration for time (p = 0.002), an interaction of time and motor-function (p = 0.005) and an effect of motor-function level on the area under the curve (p = 0.034) for Wii-golf. This study demonstrated different patterns of EMG changes according to residual voluntary motor-function levels, despite heterogeneity within each level that was not evident following clinical assessments alone. Thus, rehabilitation efficacy might be underestimated by analyses of pooled data