Posts Tagged Hemiparetic

[ARTICLE] Upper Extremity Motor Impairments and Microstructural Changes in Bulbospinal Pathways in Chronic Hemiparetic Stroke – Full Text

Following hemiparetic stroke, precise, individuated control of single joints is often replaced by highly stereotyped patterns of multi-joint movement, or abnormal limb synergies, which can negatively impact functional use of the paretic arm. One hypothesis for the expression of these synergies is an increased dependence on bulbospinal pathways such as the rubrospinal (RubST) tract and especially the reticulospinal (RetST) tracts, which co-activate multiple muscles of the shoulder, elbow, wrist, and fingers. Despite indirect evidence supporting this hypothesis in humans poststroke, it still remains unclear whether it is correct. Therefore, we used high-resolution diffusion tensor imaging (DTI) to quantify white matter microstructure in relation to severity of arm synergy and hand-related motor impairments. DTI was performed on 19 moderately to severely impaired chronic stroke individuals and 15 healthy, age-matched controls. In stroke individuals, compared to controls, there was significantly decreased fractional anisotropy (FA) and significantly increased axial and radial diffusivity in bilateral corona radiata and body of the corpus callosum. Furthermore, poststroke, the contralesional (CL) RetST FA correlated significantly with both upper extremity (UE) synergy severity (r = −0.606, p = 0.003) and hand impairment (r = −0.609, p = 0.003). FA in the ipsilesional RubST significantly correlated with hand impairment severity (r = −0.590, p = 0.004). For the first time, we separately evaluate RetST and RubST microstructure in chronic stroke individuals with UE motor impairment. We demonstrate that individuals with the greatest UE synergy severity and hand impairments poststroke have the highest FA in the CL RetST a pattern consistent with increased myelination and suggestive of neuroplastic reorganization. Since the RetST pathway microstructure, in particular, is sensitive to abnormal joint coupling and hand-related motor impairment in chronic stroke, it could help test the effects of specific, and novel, anti-synergy neurorehabilitation interventions for recovery from hemiparesis.

Introduction

Approximately 85% of stroke survivors experience significant motor impairment in the contralesional (CL) arm (1), which can include a loss of independent joint control (2, 3), weakness (4), and spasticity (5). After stroke, precise, individuated control of single joints is often replaced by highly stereotyped patterns of multi-joint movement caused by abnormal muscle co-activation patterns (6). The most prevalent of these patterns is the flexion synergy, which is characterized by an abnormal coupling of shoulder abduction and elbow, wrist, and finger flexion (7, 8). This impairment has a negative impact on reaching ability (9) and hand function (3, 10), both critical components of functional use of the arm during activities of daily living. Despite the debilitating nature of this motor impairment, the underlying neuropathophysiology is not fully understood.

One hypothesis for why the flexion synergy emerges is that following a reduction of corticofugal input from the lesioned hemisphere, there is an increased dependence on CL motor cortex and bulbospinal pathways, such as reticulospinal (RetST) and rubrospinal (RubST) tracts. Therefore, in the present study, we quantify microstructural properties in white matter of both the brain and the brainstem, focusing primarily on corticoreticulospinal and corticorubrospinal systems. We evaluate whether these microstructural properties increase in integrity in relation to arm synergy and hand impairment severity, which could be indicative of increased use.

Although the RetST was previously believed to be predominantly involved in gross movements, such as locomotion (11, 12) and posture (13, 14), recent work in primates suggests the RetST also influences the motor neurons that control forearm and intrinsic hand muscles (15). In the non-human primate, stimulation of the RetST produces ipsilateral wrist flexor, elbow flexor, and shoulder abductor activation (16), mirroring the flexion synergy pattern observed in humans poststroke. Furthermore, stimulating the RetST after a corticospinal tract (CST) lesion elicits increased excitatory post-synaptic potentials in motoneurons innervating the forearm flexor and intrinsic hand muscles (17). This evidence makes the contralesional corticoreticulospinal system a compelling candidate for underlying abnormal joint coupling in humans with hemiparetic stroke.

In the non-human primate, the RubST also contributes to reaching and grasping movements (18) and has been shown to be important in recovery of hand function after CST damage (19, 20). One study showed that increased white matter integrity in bilateral red nucleus (RN) correlated with worse clinical outcomes in humans with chronic stroke (21); however, the RubST has been reported as relatively insignificant in humans (22, 23). The evidence for whether the RetST and the RubST contribute to abnormal joint coupling and hand impairment in humans poststroke still remains indirect and inconclusive.

We used high-resolution diffusion tensor imaging (DTI) (24) tract-based spatial statistics (TBSS) (25) to perform a voxel-wise comparison of white matter microstructure between stroke and control individuals. We analyzed fractional anisotropy (FA), a measurement typically associated with tract integrity, as well as axial diffusivity (AD) and radial diffusivity (RD), which represent diffusion parallel and perpendicular to the principle direction of diffusion, respectively. Because previous studies have reported altered diffusion properties in lesioned tissue (2628), we excluded potential lesion-compromised voxels from our TBSS analysis to assess changes in normal-appearing white matter. We used the TBSS-derived white matter skeleton to investigate whether microstructural tissue properties within specific regions of the brainstem (CST, RetST, RubST) and subcortical white matter within CL motor areas [primary motor area (M1), premotor area (PM), supplementary motor area (SMA), body of the corpus callosum] are sensitive to upper extremity (UE) motor impairment in chronic stroke individuals.

We evaluated UE motor impairment using the Fugl-Meyer Assessment (FMA), a stroke-specific, performance-based motor impairment index, which measures impairments, such as loss of independent joint function, stretch reflex hyper-excitability, and altered sensation (29). It is one of the most widely used clinical scales of motor impairment poststroke (30). While previous studies have looked at diffusion MRI metrics in relation to the entire FMA score (31, 32), we used only the UE measurements of arm synergies and hand function to determine whether microstructural properties in specific white matter regions of interest (ROIs) were correlated.

In the present study, we hypothesized that microstructural integrity in specific regions of the extrapyramidal brainstem would be increased in chronic stroke in a manner sensitive to synergy and hand-related impairment severity. We demonstrate a significant decrease in FA in bilateral corona radiata and body of the corpus callosum in chronic stroke when compared to controls; however, within stroke subjects, specific brainstem regions show the highest FA in individuals with the most synergy-driven arm and hand impairment. More precisely, we describe the relation between CL RetST integrity and both expression of synergy and hand impairment and between ipsilesional (IL) RubST integrity and hand impairment in chronic hemiparetic stroke individuals.[…]

Continue —> Frontiers | Upper Extremity Motor Impairments and Microstructural Changes in Bulbospinal Pathways in Chronic Hemiparetic Stroke | Neurology

Figure 1. Region of interest masks in Montreal Neurological Institute’s space. (A) Primary motor area (red), supplementary motor area (green), premotor area (blue), (B) body of the corpus callosum (light blue), (C) horizontal midbrain cross-section showing cerebral peduncle (CP) portion of the corticospinal tract (yellow) and red nucleus (RN) (red), (D) horizontal pontine cross-section showing reticular formation (RF) (green), and (E) sagittal brainstem showing RF including reticulospinal (green) and RN including rubrospinal tracts (red).

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[Abstract] The Impact of Shoulder Abduction Loading on Volitional Hand Opening and Grasping in Chronic Hemiparetic Stroke

Background. Up to 60% of individuals with moderate to severe chronic hemiparetic stroke experience excessive involuntary wrist/finger flexion that constrains functional hand movements including hand opening. It’s not known how stroke-induced brain injury impacts volitional hand opening and grasping forces as a result of the expression of abnormal coupling between shoulder abduction and wrist/finger flexion or the flexion synergy.

Objective. The goal of this study is to understand how shoulder abduction loading affects volitional hand opening and grasping forces in individuals with moderate to severe chronic hemiparetic stroke.

Methods. Thirty-six individuals (stroke, 26; control, 10) were recruited for this study. Each participant was instructed to perform maximal hand opening and grasping forces while the arm was either fully supported or lifted with a weight equal to 25% or 50% of the participant’s maximal shoulder abduction torque. Hand pentagon area, defined as the area formed by the tips of thumb and fingers, was calculated during hand opening. Forces were recorded during grasping.

Results. In individuals with moderate stroke, increasing shoulder abduction loading reduced the ability to maximally open the hand. In individuals with severe stroke, who were not able to open the hand, grasping forces were generated and increased with shoulder abduction loading. Stroke individuals also showed a reduced ability to control volitional grasping forces due to the enhanced expression of flexion synergy.

Conclusions. Shoulder abduction loading reduced the ability to volitionally open the hand and control grasping forces after stroke. Neural mechanisms and clinical implications of these findings are discussed.

Source: The Impact of Shoulder Abduction Loading on Volitional Hand Opening and Grasping in Chronic Hemiparetic Stroke – Mar 08, 2017

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[ARTICLE] Validity of gait asymmetry estimation by using an accelerometer in individuals with hemiparetic stroke – Full Text PDF

Abstract.

[Purpose] The purpose of this study was to evaluate the validity of estimating step time and length asymmetries, using an accelerometer against force plate measurements in individuals with hemiparetic stroke.

[Subjects and Methods] Twenty-four individuals who previously had experienced a stroke were asked to walk without using a cane or manual assistance on a 16-m walkway. Step time and length were measured using force plates, which is the gold standard for assessing gait asymmetry. In addition to ground reaction forces, trunk acceleration was simultaneously measured using an accelerometer. To estimate step time asymmetry using accelerometer data, the time intervals between forward acceleration peaks for each leg were calculated. To estimate step length asymmetry using accelerometer data, the integration of the positive vertical accelerations following initial contact of each leg was calculated. Asymmetry was considered the affected side value divided by the unaffected side value.

[Results] Significant correlations were found between the accelerometer and the force plates for step time and length asymmetries (rho=0.83 and rho=0.64, respectively).

[Conclusion] An accelerometer might be useful for assessing step time and length asymmetries in individuals with hemiparetic stroke, although improvements are needed for estimating the accuracy of step length asymmetry.

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[WEB SITE] ReGrasp by Rehabtronics

The ReGrasp FES hand stimulator system is the most state-of-the-art hand stimulator available.

more —>: ReGrasp by Rehabtronics

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[ARTICLE] Effect of home-based training using a slant board with dorsiflexed ankles on walking function in post-stroke hemiparetic patients – Full Text PDF

Abstract.

[Purpose] To investigate the effects of a 30-day rehabilitation program using a slant board on walking function in post-stroke hemiparetic patients.

[Subjects and Methods] Six hemiparetic patients with gait disturbance were studied. The patients were instructed to perform a home-based rehabilitation program using a slant board, thrice daily for 30 days, the exercise included standing on the slant board for 3 minutes, with both ankles dorsiflexed without backrest. For all patients, the Brunnstrom Recovery Stage, Barthel Index, range of motion of the ankle joint, modified Ashworth scale scole for calf muscle, sensory impairments with Numeral Rating Scale, maximum walking speed, number of steps, and Timed “Up and Go” test were serially evaluated at the beginning and end of the 30-day program.

[Results] The program significantly increased walking velocity, decreased the number of steps in the 10-m walking test, and decreased Timed “Up and Go” test performance time.

[Conclusion] This rehabilitation program using the slant board was safe and improved walking function in patients. The improvement in walking function could be due to a forward shift of the center of gravity, which can be an important part of motor learning for gait improvement.
INTRODUCTION

Fig. 1. The slant board used in this study The slant angle was set at 20 degrees

Stroke is a leading cause of long-term disability, and the absolute number of patients with stroke is increasing. Of the neurological sequelae that cause functional disability, hemiparesis is the most common. The incidence of gait disturbance due to hemiparesis is reportedly relatively high among chronic stroke patients1, 2). The occurrence of this disability leads to marked impairment of quality of life and the sense of well-being3, 4). In addition, the burden of caregivers is anticipated to increase when patients are in need of assistance for walking5). Improved walking ability is one of the most common goals for post-stroke hemiparetic patients6, 7). A slant board has been used as a therapeutic device for patients with spastic lower hemiparesis. Standing on the toe-up inclination surface stretches the calf muscles, which reduces the pathologically increased lower limb muscle tone in post-stroke hemiparetic patients. Standing without a back rest on the slant board can produce a forward shift in the center of pressure in healthy adults and hemiparetic patients, as reported in our previous study. Kluzak reported that standing on an inclined surface resulted in an after-effect of learning in healthy, blindfolded subjects when they returned to standing on a horizontal surface8). Subjects leaned forward after they stood on a toes-up inclination surface. Recent reports described other benefits of using the board in healthy adults and hemiparetic patients, such as movement of “center of pressure”9), and possible increase in the maximum range of “center of gravity” in the antero-posterior direction10).
Neurophysiological studies have also demonstrated increased contraction of the anterior tibialis muscle in healthy subjects standing on the slant board11). Daily home-based rehabilitation using the slant board was hypothesized to improve gait in post-stroke hemiparetic patients. To test the hypothesis, the present study investigated the effects of a 30-day home-based daily rehabilitation program using the slant board on walking function in post-stroke hemiparetic patients.

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[Abstract] The effect of a wrist-hand stretching device for spasticity in chronic hemiparetic stroke patients. – Europe PubMed Central

Abstract

The majority of these stretching devices have focused on spasticity of the leg and only a few devices have been developed for spasticity of the wrist and hand. In addition, most of these devices were large and complicated, with less easy applicability for personal use.

To investigate the effect of a stretching device for spasticity of the wrist and hand in chronic hemiparetic stroke patients.Prospective single blind randomized controlled clinical trial.

Outpatients.Patients were randomly assigned to either the intervention group(11 patients) or the control group(10 patients). The stretching device consisted of a circular shaped plastic plate and five holders to immobilize the fingers. In position 1, finger tips were facing forward, position 2 was 90° external rotation from position 1, and position 3 was 90° external rotation from position 2. Each position was maintained for 4 minutes and a rest period of 1 minute was given, therefore, one session was performed for 14 minutes. The stretching program was conducted 3 sessions/day, 6 days/week for 4 weeks. Spasticity(modified Ashworth scale [MAS]) and motor function(Fugl-Meyer motor assessment [FMA], Active Range of Motion [AROM]) of affected wrist and hand were assessed three times(first assessment; Pre, second assessment; Post-2 weeks, third assessment; Post-4 weeks).

In the intervention group, significant differences in the wrist and hand MAS and FMA were observed between three assessment times(p<0.05). However, no significant differences in the wrist and hand AROM were observed between three assessment times(p>0.05). In the control group, no differences in MAS, FMA, and AROM were observed between three assessment times(p>0.05).Findings showed that this stretching device was effective in terms of relieving spasticity and functional recovery.This stretching device is effective in spasticity reducing and motor function improvement. Moreover, it is useful to patient because it is easy to use and portable.

Source: The effect of a wrist-hand stretching device for spasticity in chronic hemiparetic stroke patients. – Abstract – Europe PubMed Central

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[ARTICLE] Effectiveness of Virtual Reality Game on Functional Movement and Activities of Daily Living in Hemiparetic Stroke Patients.

Abstract:

Independent activities of daily living (ADLs) performance are recognized as a major goal of stroke rehabilitation. Recently, virtual reality training using a video game is considered as an effective approach to improve functional activity of stroke patients.

The purpose of this study is to investigate the effects of virtual reality game using a wii fit balance board on functional movement and ADLs of hemiparetic stroke patients.

20 subjects were randomly allocated into two groups: the virtual reality game training (n = 10) and control groups (n = 10). Both groups participated in standard rehabilitation program for 6 weeks. In addition, virtual reality game training group participated in virtual reality game training for 30 minutes per day, 3 times a week, for 6 weeks.

Virtual reality game training program consisted of balance bubble, ski slalom, ski jump, soccer heading, table tiling, and the penguin slide was conducted with the Wii-Fit balance board. After 6 weeks virtual reality game training, significant improvement observed in functional movement and ADL performance in the virtual reality game training group compared to the control group.

Findings of this study demonstrated that the virtual reality game training has an effective on functional movement and ADL performance in hemiparetic stroke patients when added to standard rehabilitation.

Source: Effectiveness of Virtual Reality Game on Functional Movement and …: ingentaconnect

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[ARTICLE] Upper limb immobilisation: A neural plasticity model with relevance to post-stroke motor rehabilitation – Full Text PDF

Abstract

Advances in our knowledge about the neural plasticity that occurs after hemiparetic stroke have contributed to the formulation of theories of post-stroke motor recovery. Such theories, in turn, have underpinned contemporary motor rehabilitation strategies for treating motor deficits after stroke, such as upper limb hemiparesis.

However, a relative drawback has been that, in general, these strategies are most compatible to the recovery profiles of high-functioning stroke survivors, and therefore they do not easily translate into benefit to those individuals sustaining low-functioning upper limb hemiparesis, who otherwise have poorer residual function. For these individuals, alternative motor rehabilitation strategies are needed.

In this article, we will review upper limb immobilisation studies that have been conducted with adult healthy humans and animals. Then, we will discuss how the findings from these studies could inspire the creation of a neural plasticity model that is likely to be of particular relevance to the context of motor rehabilitation after stroke. For instance, as will be elaborated, such model could contribute to the development of alternative motor rehabilitation strategies for treating post-stroke upper limb hemiparesis.

The implications of the findings from those immobilisation studies for contemporary motor rehabilitation strategies will also be discussed and perspectives for future research in this arena will be provided as well.

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[ARTICLE] Upper limb immobilisation: A neural plasticity model with relevance to post-stroke motor rehabilitation – Full Text PDF

Abstract

Advances in our knowledge about the neural plasticity that occurs after hemiparetic stroke have contributed to the formulation of theories of post-stroke motor recovery. Such theories, in turn, have underpinned contemporary motor rehabilitation strategies for treating motor deficits after stroke, such as upper limb hemiparesis. However, a relative drawback has been that, in general, these strategies are most compatible to the recovery profiles of high-functioning stroke survivors, and therefore they do not easily translate into benefit to those individuals sustaining low-functioning upper limb hemiparesis, who otherwise have poorer residual function. For these individuals, alternative motor rehabilitation strategies are needed. In this article, we will review upper limb immobilisation studies that have been conducted with adult healthy humans and animals. Then, we will discuss how the findings from these studies could inspire the creation of a neural plasticity model that is likely to be of particular relevance to the context of motor rehabilitation after stroke. For instance, as will be elaborated, such model could contribute to the development of alternative motor rehabilitation strategies for treating post-stroke upper limb hemiparesis. The implications of the findings from those immobilisation studies for contemporary motor rehabilitation strategies will also be discussed and perspectives for future research in this arena will be provided as well.

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[ARTICLE] Home-based Neurologic Music Therapy for Upper Limb Rehabilitation with Stroke Patients at Community Rehabilitation Stage – a Feasibility Study Protocol.

Background: Impairment of upper limb function following stroke is more common than lower limb impairment and is also more resistant to treatment. Several lab-based studies with stroke patients have produced statistically significant gains in upper limb function when using musical instrument playing and techniques where rhythm acts as an external time-keeper for the priming and timing of upper limb movements.

Methods: For this feasibility study a small sample size of 14 participants (3 – 60 months post stroke) has been determined through clinical discussion between the researcher and study host in order to test for management, feasibility and effects, before planning a larger trial determined through power analysis. A cross-over design with five repeated measures will be used, whereby participants will be randomized into either a treatment (n=7) or wait list control (n=7) group. Intervention will take place twice weekly over 6 weeks. The ARAT and 9HPT will be used to measure for quantitative gains in arm function and finger dexterity, pre/post treatment interviews will serve to investigate treatment compliance and tolerance. A lab based EEG case comparison study will be undertaken to explore audio-motor coupling, brain connectivity and neural reorganization with this intervention, as evidenced in similar studies.

Discussion: Before evaluating the effectiveness of a home-based intervention in a larger scale study, it is important to assess whether implementation of the trial methodology is feasible. This study investigates the feasibility, efficacy and patient experience of a music therapy treatment protocol comprising a chart of 12 different instrumental exercises and variations, which aims at promoting measurable changes in upper limb function in hemiparetic stroke patients. The study proposes to examine several new aspects including home-based treatment and dosage, and will provide data on recruitment, adherence and variability of outcomes.

Source: Frontiers | Home-based Neurologic Music Therapy for Upper Limb Rehabilitation with Stroke Patients at Community Rehabilitation Stage – a Feasibility Study Protocol. | Frontiers in Human Neuroscience

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