Posts Tagged Motor

[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

, , , ,

Leave a comment

[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

, , , , , , ,

Leave a comment

[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

, , , , , , , , ,

Leave a comment

[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

, , , , , , , , , ,

Leave a comment

[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

, , , , , , ,

Leave a comment

[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

, , , , , , , , ,

Leave a comment

[Abstract] Role of contralesional hemisphere in paretic arm reaching in patients with severe arm paresis due to stroke: A preliminary report

Highlights

  • The functional relevance of contralesional hemisphere in paretic arm motor performance in individuals with severe arm paresis was examined.
  • TMS pulses were delivered to the contralesional primary motor and dorsal pre-motor areas.
  • Various temporal and spatial characteristics were measured in conditions with and without TMS.
  • Movement time was significantly slower with TMS to contralesional hemisphere.
  • The study suggests functionally relevant role of contralesional hemisphere motor areas during paretic arm reaching movements in stroke survivors.


Abstract

Stroke is highly prevalent and a leading cause of serious, long-term disability among American adults. Impaired movement (i.e. paresis) of the stroke-affected arm is a major contributor to post-stroke disability, yet the mechanisms of upper extremity motor recovery are poorly understood, particularly in severely impaired patients who lack hand function.

To address this problem, we examined the functional relevance of the contralesional hemisphere in paretic arm motor performance in individuals with severe arm paresis.

Twelve individuals with severe stroke-induced arm paresis (Upper Extremity Fugl-Meyer Assessment = 17.1 ± 8.5; maximum score = 66) participated in the study.

Participants performed a reaching response time task with their paretic arm. At varying time intervals following a ‘Go’ cue, a pair of transcranial magnetic stimulation (TMS) pulses were delivered to contralesional hemisphere primary motor (M1) or dorsal pre-motor cortex (PMd) to momentarily disrupt the pattern of neural firing. Response time components and hand-path characteristics were compared across the 2 sites for trials with and without TMS disruption. There was no significant effect of TMS disruption on overall Response time or Reaction time, but Movement time was significantly longer (i.e. slower) with disruption of the contralesional hemisphere (p = 0.015), regardless of which area was stimulated. Peak hand-path velocity and hand-path smoothness were also significantly lower (p = 0.005 and p < 0.0001, respectively) with TMS disruption of the contralesional hemisphere.

The data from this study provide evidence supporting a functionally relevant role of contralesional hemisphere motor areas in paretic arm reaching movements in individuals with severe post-stroke arm impairment.

Source: Role of contralesional hemisphere in paretic arm reaching in patients with severe arm paresis due to stroke: A preliminary report

, , , , , , ,

Leave a comment

[ARTICLE] The application of virtual reality in neuro-rehabilitation: motor re-learning supported by innovative technologies – Full Text PDF

Abstract
The motor function impairment resulting from a stroke injury has a negative impact on autonomy, the activities of daily living thus the individuals affected by a stroke need long-term rehabilitation. Several studies have demonstrated that learning new
motor skills is important to induce neuroplasticity and functional recovery.

Innovative technologies used in rehabilitation allow one the possibility to enhance training throughout generated feedback. It seems advantageous to combine traditional motor rehabilitation with innovative technology in order to promote motor re-learning and skill re-acquisition by means of enhanced training.

An environment enriched by feedback involves multiple sensory modalities and could promote active patient participation. Exercises in a virtual environment contain elements necessary to maximize motor learning, such as repetitive and differentiated task practice and feedback on the performance and results. The recovery of the limbs motor function in post-stroke subjects is one of the main therapeutic aims for patients and physiotherapist alike.

Virtual reality as well as robotic devices allow one to provide specific treatment based on the reinforced feedback in a virtual environment (RFVE), artificially augmenting the sensory information coherent with the real-world objects and events. Motor training based on RFVE is emerging as an effective motor learning based techniques for the treatment of the extremities.

more –> Full Text PDF

, , , , , , , , , ,

Leave a comment

[ARTICLE] Robotic Therapy Provides a Stimulus for Upper Limb Motor Recovery After Stroke That Is Complementary to and Distinct From Conventional Therapy

Abstract

Background. Individuals with chronic stroke often have long-lasting upper extremity impairments that impede function during activities of daily living. Rehabilitation robotics have shown promise in improving arm function, but current systems do not allow realistic training of activities of daily living. We have incorporated the ARMin III and HandSOME device into a novel robotic therapy modality that provides functional training of reach and grasp tasks.

Objective. To compare the effects of equal doses of robotic and conventional therapy in individuals with chronic stroke.

Methods. Subjects were randomized to 12 hours of robotic or conventional therapy and then crossed over to the other therapy type after a 1-month washout period. Twelve moderate to severely impaired individuals with chronic stroke were enrolled, and 10 completed the study.

Results. Across the 3-month study period, subjects showed significant improvements in the Fugl-Meyer (P = .013) and Box and Blocks tests (P = .028). The robotic intervention produced significantly greater improvements in the Action Research Arm Test than conventional therapy (P = .033). Gains in the Box and Blocks test from conventional therapy were larger than from robotic therapy in subjects who received conventional therapy after robotic therapy (P = .044).

Conclusions. Data suggest that robotic therapy can elicit improvements in arm function that are distinct from conventional therapy and supplements conventional methods to improve outcomes. Results from this pilot study should be confirmed in a larger study.

via Robotic Therapy Provides a Stimulus for Upper Limb Motor Recovery After Stroke That Is Complementary to and Distinct From Conventional Therapy.

, , , , , , , , , , , ,

Leave a comment

[WEB SITE] Novel rehabilitation device improves motor skills after stroke

…Using a novel stroke rehabilitation device that converts an individual’s thoughts to electrical impulses to move upper extremities, stroke patients reported improvements in their motor function and ability to perform activities of daily living. Results of the study were presented today at the annual meeting of the Radiological Society of North America (RSNA)…

via Novel rehabilitation device improves motor skills after stroke.

, , ,

Leave a comment

%d bloggers like this: