Posts Tagged Motor

[ARTICLE] Low-Frequency Repetitive Transcranial Magnetic Stimulation for Stroke-Induced Upper Limb Motor Deficit: A Meta-Analysis – Full Text

Abstract

Background and Purpose. This meta-analysis aimed to evaluate the therapeutic potential of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) over the contralesional hemisphere on upper limb motor recovery and cortex plasticity after stroke. Methods. Databases of PubMed, Medline, ScienceDirect, Cochrane, and Embase were searched for randomized controlled trials published before Jun 31, 2017. The effect size was evaluated by using the standardized mean difference (SMD) and a 95% confidence interval (CI). Resting motor threshold (rMT) and motor-evoked potential (MEP) were also examined. Results. Twenty-two studies of 1 Hz LF-rTMS over the contralesional hemisphere were included. Significant efficacy was found on finger flexibility (SMD = 0.75), hand strength (SMD = 0.49), and activity dexterity (SMD = 0.32), but not on body function (SMD = 0.29). The positive changes of rMT (SMD = 0.38 for the affected hemisphere and SMD = −0.83 for the unaffected hemisphere) and MEP (SMD = −1.00 for the affected hemisphere and SMD = 0.57 for the unaffected hemisphere) were also significant. Conclusions. LF-rTMS as an add-on therapy significantly improved upper limb functional recovery especially the hand after stroke, probably through rebalanced cortical excitability of both hemispheres. Future studies should determine if LF-rTMS alone or in conjunction with practice/training would be more effective. Clinical Trial Registration Information. This trial is registered with unique identifier CRD42016042181.

1. Introduction

Stroke is a global disease with high rates of long-term disability [1]. Around the world, 25%–74% of stroke survivors require different levels of assistance for daily living mainly due to upper limb hemiplegia [2]. In search for better therapies, scientists have been trying to understand the relationship between stroke motor recovery and cortical reorganization [3]. The equilibrium of cortical excitability between the two hemispheres is often disrupted after stroke. In the affected hemisphere, both the cortical excitability and the homonymous motor representation of the affected hemisphere decrease; whereas the excitability in the unaffected hemisphere increases [4].

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive stimulation to induce electrical currents in the brain tissues. Currently, rTMS is being explored as a novel therapy in modulating cortical excitability to improve motor functions in stroke patients [5]. Of the two forms of rTMS, high-frequency rTMS (HF-rTMS > 1.0 Hz), applied over the ipsilesional hemisphere, facilitates cortical excitability [6], whereas, low-frequency rTMS (LF-rTMS ≤ 1.0 Hz), applied over the contralesional hemisphere, decreases cortical excitability [7].

The effect of rTMS is primarily determined by the stimulation frequency [8] and targeted region [3]. Although both LF-rTMS and HF-rTMS could treat motor dysfunction in poststroke patients, LF-rTMS is considered safer and superior to HF-rTMS in motor function recovery [912]. Lomarev et al. [13] reported increased risk for seizures by HF-rTMS of 20–25 Hz. To date, the majority of rTMS trials on motor recovery after stroke used the protocol of LF-rTMS with 1 Hz. In comparison, the HF-rTMS studies involved only a small number of trials and applied varied frequency protocols (3 Hz to 25 Hz). According to Cho et al. [14], the primary motor cortex (M1) forms a main part of the motor cortices and contributes to the high order control of motor behaviors. Until now, most studies about the efficacy of LF-rTMS on functional rehabilitation have focused on the M1. In healthy subjects, LF-rTMS applied over the M1 increased the resting motor threshold (rMT) and decreased the motor-evoked potential (MEP) size of the ipsilateral hemisphere, suggesting a suppressive effect of LF-rTMS in the intact M1 [15].

Multiple studies have investigated the therapeutic effect of LF-rTMS after stroke [81619], with the outcomes of pinch force [1922], grip force [102225], finger tapping [892629], and overall function [153034]. Other studies also explored the impact of rTMS on cortical excitability [10181926]. However, inconsistent reports exist regarding the benefits of LF-rTMS: Some studies showed no beneficial effect of LF-rTMS [162329] and one study reported worsening effects of LF-rTMS such as decreased finger-tapping speed; [35] other investigators proposed that inhibition of the contralesional motor areas may lead to deterioration of the function of the unaffected hand [2426]. Although a few previous meta-analyses had investigated the therapeutic effect of rTMS after stroke [113638], they focused on the mixed effect of combined LF-rTMS and HF-rTMS interventions or on the combined outcomes of varying motor measurements. So far, there is a lack of in-depth systematic meta-analysis about the efficacy of LF-rTMS on upper limb function recovery.

The primary objective of this study was to evaluate the effects of LF-rTMS on upper limb motor recovery after stroke in several aspects: “finger flexibility,” “hand strength,” “activity dexterity,” and “body function level.” The effects of LF-rTMS on motor cortex excitability which were represented by MEP and rMTin poststroke patients were also evaluated. […]

Continue —>  Low-Frequency Repetitive Transcranial Magnetic Stimulation for Stroke-Induced Upper Limb Motor Deficit: A Meta-Analysis

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[Abstract] Motor Recovery Beginning 23 Years After Ischemic Stroke

Abstract

It is widely believed that most stroke recovery occurs within 6 months, with little benefit of physiotherapy or other modalities beyond a year. We report a remarkable case of stroke recovery beginning 23 years after a severe stroke due to embolization from the innominate artery and subclavian artery, resulting from compression of the right subclavian artery by a cervical rib. The patient had a large right fronto-parietal infarction with severe left hemiparesis, and a totally non-functional spastic left hand. He experienced some recovery of hand function that began 23 years after the stroke, a year after he took up regular swimming. As a result, intensive physiotherapy was initiated, with repetetive large muscle movement and a spring-loaded mechanical orthosis that provides resistance to finger flexors and supports finger extensors. Within two years he could pick up coins with the previously useless left hand. Functional MRI studies document widespread distribution of the recovery in both hemispheres. This case provides impetus not only to more intensive and prolonged physiotherapy, but also to treatment with emerging modalities such as stem cell therapy, exosome and micro-RNA therapies.

Source: ARTICLES | Journal of Neurophysiology

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[ARTICLE] Biomarkers of stroke recovery: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation Roundtable – Full Text

In practical terms, biomarkers should improve our ability to predict long-term outcomes after stroke across multiple domains. This is beneficial for: (a) patients, caregivers and clinicians; (b) planning subsequent clinical pathways and goal setting; and (c) identifying whom and when to target, and in some instances at which dose, with interventions for promoting stroke recovery.2 This last point is particularly important as methods for accurate prediction of long-term outcome would allow clinical trials of restorative and rehabilitation interventions to be stratified based on the potential for neurobiological recovery in a way that is currently not possible when trials are performed in the absence of valid biomarkers. Unpredictable outcomes after stroke, particularly in those who present with the most severe impairment3 mean that clinical trials of rehabilitation interventions need hundreds of patients to be appropriately powered. Use of biomarkers would allow incorporation of accurate information about the underlying impairment, and thus the size of these intervention trials could be considerably reduced,4 with obvious benefits. These principles are no different in the context of stroke recovery as compared to general medical research.5

Interventions fall into two broad mechanistic categories: (1) behavioural interventions that take advantage of experience and learning-dependent plasticity (e.g. motor, sensory, cognitive, and speech and language therapy), and (2) treatments that enhance the potential for experience and learning-dependent plasticity to maximise the effects of behavioural interventions (e.g. pharmacotherapy or non-invasive brain stimulation).6 To identify in whom and when to intervene, we need biomarkers that reflect the underlying biological mechanisms being targeted therapeutically.

Our goal is to provide a consensus statement regarding the evidence for SRBs that are helpful in outcome prediction and therefore identifying subgroups for stratification to be used in trials.7 We focused on SRBs that can investigate the structure or function of the brain (Table 1). Four functional domains (motor, somatosensation, cognition, and language (Table 2)) were considered according to recovery phase post stroke (hyperacute: <24 h; acute: 1 to 7 days; early subacute: 1 week to 3 months; late subacute: 3 months to 6 months; chronic: > 6 months8). For each functional domain, we provide recommendations for biomarkers that either are: (1) ready to guide stratification of subgroups of patients for clinical trials and/or to predict outcome, or (2) are a developmental priority (Table 3). Finally, we provide an example of how inclusion of a clinical trial-ready biomarker might have benefitted a recent phase III trial. As there is generally limited evidence at this time for blood or genetic biomarkers, we do not discuss these, but recommend they are a developmental priority.912 We also recognize that many other functional domains exist, but focus here on the four that have the most developed science. […]

Continue —> Biomarkers of stroke recovery: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation RoundtableInternational Journal of Stroke – Lara A Boyd, Kathryn S Hayward, Nick S Ward, Cathy M Stinear, Charlotte Rosso, Rebecca J Fisher, Alexandre R Carter, Alex P Leff, David A Copland, Leeanne M Carey, Leonardo G Cohen, D Michele Basso, Jane M Maguire, Steven C Cramer, 2017

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[ARTICLE] Video Game Rehabilitation for Outpatient Stroke (VIGoROUS): protocol for a multi-center comparative effectiveness trial of in-home gamified constraint-induced movement therapy for rehabilitation of chronic upper extremity hemiparesis – Full Text

 

Abstract

Background

Constraint-Induced Movement therapy (CI therapy) is shown to reduce disability, increase use of the more affected arm/hand, and promote brain plasticity for individuals with upper extremity hemiparesis post-stroke. Randomized controlled trials consistently demonstrate that CI therapy is superior to other rehabilitation paradigms, yet it is available to only a small minority of the estimated 1.2 million chronic stroke survivors with upper extremity disability. The current study aims to establish the comparative effectiveness of a novel, patient-centered approach to rehabilitation utilizing newly developed, inexpensive, and commercially available gaming technology to disseminate CI therapy to underserved individuals. Video game delivery of CI therapy will be compared against traditional clinic-based CI therapy and standard upper extremity rehabilitation. Additionally, individual factors that differentially influence response to one treatment versus another will be examined.

Methods

This protocol outlines a multi-site, randomized controlled trial with parallel group design. Two hundred twenty four adults with chronic hemiparesis post-stroke will be recruited at four sites. Participants are randomized to one of four study groups: (1) traditional clinic-based CI therapy, (2) therapist-as-consultant video game CI therapy, (3) therapist-as-consultant video game CI therapy with additional therapist contact via telerehabilitation/video consultation, and (4) standard upper extremity rehabilitation. After 6-month follow-up, individuals assigned to the standard upper extremity rehabilitation condition crossover to stand-alone video game CI therapy preceded by a therapist consultation. All interventions are delivered over a period of three weeks. Primary outcome measures include motor improvement as measured by the Wolf Motor Function Test (WMFT), quality of arm use for daily activities as measured by Motor Activity Log (MAL), and quality of life as measured by the Quality of Life in Neurological Disorders (NeuroQOL).

Discussion

This multi-site RCT is designed to determine comparative effectiveness of in-home technology-based delivery of CI therapy versus standard upper extremity rehabilitation and in-clinic CI therapy. The study design also enables evaluation of the effect of therapist contact time on treatment outcomes within a therapist-as-consultant model of gaming and technology-based rehabilitation.

Background

Clinical practice guidelines recommend outpatient rehabilitation for stroke survivors who remain disabled after discharge from inpatient rehabilitation [1]. Although these guidelines recommend that the majority of stroke survivors receive at least some outpatient rehabilitation [2], many cannot access long-term care [3]. Among those individuals who do undergo outpatient rehabilitation, the standard of care for upper extremity rehabilitation is suboptimal.

In an observational study of 312 rehabilitation sessions (83 occupational and physical therapists at 7 rehabilitation sites), Lang and colleagues [4] found that functional rehabilitation (i.e., movement that accomplishes a functional task, such as eating, as opposed to strength training or passive movement) was provided in only 51% of the sessions of upper extremity rehabilitation, with only 45 repetitions per session on average. This is concerning given that empirically-validated interventions incorporate higher doses of active motor practice [5, 6, 7]. Additionally, functional upper extremity movements are most likely to generalize to everyday tasks [8], an aspect of recovery that is critically important to patients and their families [9, 10, 11]. Yet, passive movement and non-goal-directed exercise are more frequently administered [4].

There appear to be at least two critical elements required for successful upper extremity motor rehabilitation: 1) motor practice that is sufficiently intense and 2) techniques to carryover motor improvements to functional activities. Carry-over techniques to increase a person’s use of the more affected upper extremity for daily activities are extremely important for rehabilitation and appear necessary for structural brain change [12, 13, 14, 15]. When rehabilitation incorporates these techniques, there is substantially improved improvement in self-perceived quality of arm use for daily activities [12, 16]. Carry-over techniques enable the patient to overcome the conditioned suppression of movement (learned nonuse) characteristic of chronic hemiparesis [17]. Techniques include structured self-monitoring, a treatment contract, daily home practice of specific functional motor skills, and guided problem-solving to overcome perceived barriers to using the extremity [18].

Constraint-Induced Movement therapy (CI therapy) has strong empirical backing [5, 19] and combines high-repetition functional practice of the more affected arm with behavioral techniques to enhance carry-over [13, 18]. CI therapy produces consistently superior motor performance and retention of gains versus standard upper extremity rehabilitation [20, 21], particularly when it includes the critically important carry-over (transfer package) techniques [12]. When compared to other equally intensive interventions (i.e., equal hours of training on functional tasks), CI therapy with carry-over (transfer package) techniques has also shown enhanced carry-over of clinical gains to daily activities [12, 13, 22, 23, 24] that are retained for at least 2 years [19, 25, 26, 27, 28].

Despite its inclusion in best practice recommendations [29, 30], CI therapy is available to only a very small minority of those who could benefit from it in the US. CI therapy is not typically covered by insurance and the 30+ hours of assessment and physical training cost upwards of $6000. Access barriers for the patient include limited transportation and insurance coverage, whereas therapists may have difficulty accommodating the CI therapy schedule [31, 32]. Access barriers aside, CI therapy has also been plagued by a variety of misconceptions regarding use of restraint and the transfer package. Most iterations of CI therapy employ use of a restraint mitt to promote use of the affected arm, which is viewed by many patients and clinicians as excessively prohibitive [32]. Yet, literature demonstrates that restraint is not specifically required to achieve positive outcomes [33, 34]. Moreover, the transfer package, a component found to be critical [13, 14], is omitted from the majority of research studies on CI therapy [35].

To address transportation barriers, a telerehabilitation model of CI therapy delivery (AutoCITE) has been tested. AutoCITE is a large specialized motor apparatus (not commercially available, cost not established) that was installed in patients’ homes to enable therapeutic manipulation of actual objects with continuous video monitoring via Internet. This telerehabilitation approach demonstrated efficacy approximately equivalent to that of in-clinic CI therapy [36, 37, 38], thus establishing the feasibility of utilizing technology to deliver CI therapy remotely. However, this system involved specialized equipment at a high cost and did not become available outside a research setting.

To more fully address the barriers to accessing CI therapy and to counter the misconceptions surrounding CI therapy, a patient-centered treatment approach was developed that incorporated the high-repetition practice and carry-over strategies from CI therapy, while reforming non-patient-centric elements of the protocol that lack strong empirical support (i.e., the restraint). To deliver engaging high-repetition practice, a Kinect-based video game was created that can accommodate a wide range of motor disability, can be customized to each user, and automatically progresses in difficulty as the individual’s performance improves (termed “shaping” in the CI therapy literature). A player’s body movements drive game play (there is no external controller), which makes the game easy to use for those who may be unfamiliar with technology. To date, such high-repetition practice through motor gaming [39] has shown initial promise compared to traditional clinic-based approaches [40]. To promote increased use of the weaker arm, a smart watch biofeedback application is utilized in lieu of the restraint mitt. This application counts movements made with the weaker arm and provides alerts when a period of inactivity is detected. Previous approaches for providing CI therapy in the home and reducing the amount of therapist effort have been carried out [36, 37, 38, 41]. These approaches automated the delivery of training and permitted remote supervision of the training via an Internet-based audio-visual link, but did not embed the training within the context of a video game, rely on manipulation of virtual objects, or incorporate a patient-centric substitute for the mitt.

Initial evidence from a pilot trial of this system (Borstad A, Crawfis R, Phillips K, Pax Lowes L, Worthen-Chaudhari L, Maung D, et al.: In-home delivery of constraint induced movement therapy via virtual reality gaming is safe and feasible: a pilot study, submitted) suggests that improvements in motor speed, as measured by Wolf Motor Function Test (WMFT) performance time [42], an outcome of prime importance to stroke survivors, are approximately equivalent to those reported in the traditional CI therapy literature [5, 13, 19, 25]. Qualitative data reveal that the technology is accepted irrespective of age, technological expertise, ethnicity, or cultural background. Thus, this technology has the potential to address the main barriers to adoption of CI therapy, while reducing the cost of care. A randomized clinical trial is now required to provide Level 1 evidence of the comparative effectiveness of this novel model of CI therapy delivery. Data from this trial will enable individuals with motor disability to evaluate whether a home-based video game therapy has the potential to help them meet their rehabilitation goals compared to in-clinic CI therapy and traditional approaches. By combining novel gaming elements with the transfer package from CI therapy, this trial will also address a major limitation of rehabilitation gaming interventions that have been tried to date: extremely limited emphasis on carry-over of training to daily activities.

The primary objective of this trial is to compare the effectiveness of two video game-based models of CI therapy versus traditional clinic-based CI therapy versus standard upper extremity rehabilitation for improving upper extremity motor function. One video gaming group will match the number of total hours spent on the CI therapy transfer package, but will involve fewer days of therapist-client interaction (4 versus 10); the other will match the number of interactions with a therapist to that of clinic-based CI therapy using video consultation between in-person sessions and, as such, will involve more therapist contact hours spent focusing on the transfer package. The secondary objective of this project is to promote personalized medicine by examining individual factors that may differentially influence response to one treatment versus another.

Continue —>  Video Game Rehabilitation for Outpatient Stroke (VIGoROUS): protocol for a multi-center comparative effectiveness trial of in-home gamified constraint-induced movement therapy for rehabilitation of chronic upper extremity hemiparesis | BMC Neurology | Full Text

Fig. 1 Screen capture of the Recovery Rapids gaming environment

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[Abstract] Motor Recovery Beginning 23 Years After Ischemic Stroke – Journal of Neurophysiology

Abstract

It is widely believed that most stroke recovery occurs within 6 months, with little benefit of physiotherapy or other modalities beyond a year. We report a remarkable case of stroke recovery beginning 23 years after a severe stroke due to embolization from the innominate artery and subclavian artery, resulting from compression of the right subclavian artery by a cervical rib. The patient had a large right fronto-parietal infarction with severe left hemiparesis, and a totally non-functional spastic left hand. He experienced some recovery of hand function that began 23 years after the stroke, a year after he took up regular swimming. As a result, intensive physiotherapy was initiated, with repetetive large muscle movement and a spring-loaded mechanical orthosis that provides resistance to finger flexors and supports finger extensors. Within two years he could pick up coins with the previously useless left hand. Functional MRI studies document widespread distribution of the recovery in both hemispheres. This case provides impetus not only to more intensive and prolonged physiotherapy, but also to treatment with emerging modalities such as stem cell therapy, exosome and micro-RNA therapies.

 

Source: ARTICLES | Journal of Neurophysiology

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[Abstract] TMS measures of motor cortex function after stroke: A meta-analysis

Highlights

    The neurophysiological effects of stroke are localised to the affected motor cortex.There is no clear evidence of imbalanced interhemispheric inhibition after stroke.Facilitating the affected motor cortex may be most beneficial in selected patients.

Abstract

Background

Transcranial magnetic stimulation (TMS) is commonly used to measure the effects of stroke on corticomotor excitability, intracortical function, and interhemispheric interactions. The interhemispheric inhibition model posits that recovery of motor function after stroke is linked to rebalancing of asymmetric interhemispheric inhibition and corticomotor excitability. This model forms the rationale for using neuromodulation techniques to suppress unaffected motor cortex excitability, and facilitate affected motor cortex excitability. However, the evidence base for using neuromodulation techniques to promote post-stroke motor recovery is inconclusive.

Objective

The aim of this meta-analysis was to compare measures of corticomotor excitability, intracortical function, and interhemispheric inhibition, between the affected and unaffected hemispheres of people with stroke, and measures made in healthy adults.

Methods

A literature search was conducted to identify studies that made TMS measures of the motor cortex in adult stroke patients. Two authors independently extracted data, and the quality of included studies was assessed. TMS measures were compared between the affected and unaffected hemispheres of stroke patients, between the affected hemisphere and healthy controls, and between the unaffected hemisphere and healthy controls. Analyses were carried out with data grouped according to the muscle from which responses were recorded, and separately according to time post-stroke (<3 months, and ≥6 months). Meta-analyses were carried out using a random effects model.

Results

There were 844 studies identified, and 112 studies included in the meta-analysis. Results were very similar across muscle groups. Affected hemisphere M1 excitability is lower than unaffected and healthy control M1 excitability after stroke. Affected hemisphere short interval intracortical inhibition (SICI) is lower than unaffected and healthy control SICI early after stroke, and not different in the chronic phase. There were no differences detected between the unaffected hemisphere and healthy controls. There were only seven studies of interhemispheric inhibition that could be included, with no clear effects of hemisphere or time post-stroke.

Conclusions

The neurophysiological effects of stroke are primarily localised to the affected hemisphere, and there is no clear evidence for hyper-excitability of the unaffected hemisphere or imbalanced interhemispheric inhibition. This indicates that facilitating affected M1 excitability directly may be more beneficial than suppressing unaffected M1 excitability for promoting post-stroke recovery.

Source: TMS measures of motor cortex function after stroke: A meta-analysis

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[Abstract] TMS measures of motor cortex function after stroke: A meta-analysis

Highlights

  • The neurophysiological effects of stroke are localised to the affected motor cortex.
  • There is no clear evidence of imbalanced interhemispheric inhibition after stroke.
  • Facilitating the affected motor cortex may be most beneficial in selected patients.

Abstract

Background

Transcranial magnetic stimulation (TMS) is commonly used to measure the effects of stroke on corticomotor excitability, intracortical function, and interhemispheric interactions. The interhemispheric inhibition model posits that recovery of motor function after stroke is linked to rebalancing of asymmetric interhemispheric inhibition and corticomotor excitability. This model forms the rationale for using neuromodulation techniques to suppress unaffected motor cortex excitability, and facilitate affected motor cortex excitability. However, the evidence base for using neuromodulation techniques to promote post-stroke motor recovery is inconclusive.

Objective

The aim of this meta-analysis was to compare measures of corticomotor excitability, intracortical function, and interhemispheric inhibition, between the affected and unaffected hemispheres of people with stroke, and measures made in healthy adults.

Methods

A literature search was conducted to identify studies that made TMS measures of the motor cortex in adult stroke patients. Two authors independently extracted data, and the quality of included studies was assessed. TMS measures were compared between the affected and unaffected hemispheres of stroke patients, between the affected hemisphere and healthy controls, and between the unaffected hemisphere and healthy controls. Analyses were carried out with data grouped according to the muscle from which responses were recorded, and separately according to time post-stroke (<3 months, and ≥ 6 months). Meta-analyses were carried out using a random effects model.

Results

There were 844 studies identified, and 112 studies included in the meta-analysis. Results were very similar across muscle groups. Affected hemisphere M1 excitability is lower than unaffected and healthy control M1 excitability after stroke. Affected hemisphere short interval intracortical inhibition (SICI) is lower than unaffected and healthy control SICI early after stroke, and not different in the chronic phase. There were no differences detected between the unaffected hemisphere and healthy controls. There were only seven studies of interhemispheric inhibition that could be included, with no clear effects of hemisphere or time post-stroke.

Conclusions

The neurophysiological effects of stroke are primarily localised to the affected hemisphere, and there is no clear evidence for hyper-excitability of the unaffected hemisphere or imbalanced interhemispheric inhibition. This indicates that facilitating affected M1 excitability directly may be more beneficial than suppressing unaffected M1 excitability for promoting post-stroke recovery.

Source: TMS measures of motor cortex function after stroke: A meta-analysis – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation

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[Abstract] Role of corpus callosum integrity in arm function differs based on motor severity after stroke

Highlights

    Corpus callosum structural integrity could impact motor function after stroke.Corpus callosum integrity was decreased and correlated with motor function.Correlation was strongest in the subgroup with relatively greater motor capacity.In subgroup with less motor capacity, only CST integrity correlated with motor function.

Abstract

While the corpus callosum (CC) is important to normal sensorimotor function, its role in motor function after stroke is less well understood.

This study examined the relationship between structural integrity of the motor and sensory sections of the CC, as reflected by fractional anisotropy (FA), and motor function in individuals with a range of motor impairment level due to stroke.

Fifty-five individuals with chronic stroke (Fugl-Meyer motor score range 14 to 61) and 18 healthy controls underwent diffusion tensor imaging and a set of motor behavior tests. Mean FA from the motor and sensory regions of the CC and from corticospinal tract (CST) were extracted and relationships with behavioral measures evaluated. Across all participants, FA in both CC regions was significantly decreased after stroke (p < 0.001) and showed a significant, positive correlation with level of motor function. However, these relationships varied based on degree of motor impairment: in individuals with relatively less motor impairment (Fugl-Meyer motor score > 39), motor status correlated with FA in the CC but not the CST, while in individuals with relatively greater motor impairment (Fugl-Meyer motor score ≤ 39), motor status correlated with FA in the CST but not the CC.

The role interhemispheric motor connections play in motor function after stroke may differ based on level of motor impairment. These findings emphasize the heterogeneity of stroke, and suggest that biomarkers and treatment approaches targeting separate subgroups may be warranted.

Source: Role of corpus callosum integrity in arm function differs based on motor severity after stroke

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[Abstract] Effects of tDCS on motor learning and memory formation: a consensus and critical position paper – Clinical Neurophysiology

Highlights

  • We review investigations of whether tDCS can facilitate motor skill learning and adaptation.
  • We identify several caveats in the existing literature and propose solutions for addressing these.
  • Open Science efforts will improve standardization, reproducibility and quality of future research.

Abstract

Motor skills are required for activities of daily living. Transcranial direct current stimulation (tDCS) applied in association with motor skill learning has been investigated as a tool for enhancing training effects in health and disease. Here, we review the published literature investigating whether tDCS can facilitate the acquisition, retention or adaptation of motor skills. Work in multiple laboratories is underway to develop a mechanistic understanding of tDCS effects on different forms of learning and to optimize stimulation protocols. Efforts are required to improve reproducibility and standardization. Overall, reproducibility remains to be fully tested, effect sizes with present techniques vary over a wide range, and the basis of observed inter-individual variability in tDCS effects is incompletely understood. It is recommended that future studies explicitly state in the Methods the exploratory (hypothesis-generating) or hypothesis-driven (confirmatory) nature of the experimental designs. General research practices could be improved with prospective pre-registration of hypothesis-based investigations, more emphasis on the detailed description of methods (including all pertinent details to enable future modeling of induced current and experimental replication), and use of post-publication open data repositories. A checklist is proposed for reporting tDCS investigations in a way that can improve efforts to assess reproducibility.

Source: Effects of tDCS on motor learning and memory formation: a consensus and critical position paper – Clinical Neurophysiology

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[WEB SITE] NeuroRehabLab | Exploring the human brain through Virtual Environment interaction

OUR MISSION

The NeuroRehabLab is an interdisciplinary research group of the University of Madeira that investigates at the intersection of technology, neuroscience and clinical practice to find novel solutions to increase the quality of life of those with special needs. We capitalize on Virtual Reality, Serious Games, and Brain-Computer Interfaces to exploit specific brain mechanisms that relate to functional recovery to approach motor and cognitive rehabilitation by means of non-invasive and low-cost technologies.

more —> NeuroRehabLab | Exploring the human brain through Virtual Environment interaction

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