Is it possible to facilitate neural plasticity for enhancing post chronic stroke recovery?

Severe impairment of limb movement after stroke can be challenging to address in the chronic stage of stroke (e.g., greater than 6 months post stroke). Recent evidence suggests that physical therapy can still promote meaningful recovery after this stage, but the required high amount of therapy is difficult to deliver within the scope of standard clinical practice. Digital gaming technologies are now being combined with brain–computer interfaces to motivate engaging and frequent exercise and promote neural recovery. However, the complexity and expense of acquiring brain signals has held back widespread utilization of these rehabilitation systems. Furthermore, for people that have residual muscle activity, electromyography (EMG) might be a simpler and equally effective alternative. In this pilot study, we evaluate the feasibility and efficacy of an EMG-based variant of our REINVENT virtual reality (VR) neurofeedback rehabilitation system to increase volitional muscle activity while reducing unintended co-contractions. We recruited four participants in the chronic stage of stroke recovery, all with severely restricted active wrist movement. They completed seven 1-hour training sessions during which our head-mounted VR system reinforced activation of the wrist extensor muscles without flexor activation. Before and after training, participants underwent a battery of clinical and neuromuscular assessments. We found that training improved scores on standardized clinical assessments, equivalent to those previously reported for brain–computer interfaces. Additionally, training may have induced changes in corticospinal communication, as indexed by an increase in 12–30 Hz corticomuscular coherence and by an improved ability to maintain a constant level of wrist muscle activity. Our data support the feasibility of using muscle–computer interfaces in severe chronic stroke, as well as their potential to promote functional recovery and trigger neural plasticity.

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The Impact of Neurofeedback on Effective Connectivity Networks in Chronic Stroke Patients

10.1101/2020.05.04.20087163 ◽

2020 ◽

Author(s):

Lioi Giulia ◽

Veliz Adolfo ◽

Coloigner Julie ◽

Duché Quentin ◽

Butet Simon ◽

...

Keyword(s):

Neural Plasticity ◽

Large Scale ◽

Scale Effects ◽

Self Regulation ◽

Chronic Stroke ◽

Causal Modeling ◽

Stroke Recovery ◽

Functional Improvement ◽

Stroke Patients ◽

The Impact

AbstractStroke is a complex motor disease that not only affects perilesional areas but also global brain networks in both hemispheres. Neurofeedback (NF) is a promising technique to enhance neural plasticity and support functional improvement after stroke by means of brain self-regulation. Most of the studies using NF or brain computer interfaces for stroke rehabilitation have assessed treatment effects focusing on motor outcomes and successful activation of targeted cortical regions. However, given the crucial role of large-scale networks reorganization for stroke recovery, it is now believed that assessment of brain connectivity is central to predict treatment response and to individualize rehabilitation therapies. In this study, we assessed the impact of EEG-fMRI NF training on connectivity strength and direction using a Dynamic Causal Modeling approach. We considered a motor network including both ipsilesional and contralesional premotor, supplementary and primary motor areas. Our results in nine chronic stroke patients indicate that NF upregulation of targeted areas (ipsilesional SMA and M1) not only modulated activation patterns, but also had a more widespread impact on fMRI bilateral motor networks. In particular, inter-hemispheric connectivity between premotor and primary motor regions decreased, and ipsilesional self-inhibitory connections were reduced in strength, indicating an increase in activation during the NF motor task. To the best of our knowledge, this is the first work that investigates fMRI connectivity changes elicited by training of localized motor targets in stroke. Our results open new perspectives in the understanding of large-scale effects of NF training and the design of more effective NF strategies, based on the pathophysiology underlying stroke-induced deficits.

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Investigating the Intervention Parameters of Endogenous Paired Associative Stimulation (ePAS)

Brain Sciences ◽

10.3390/brainsci11020224 ◽

2021 ◽

Vol 11 (2) ◽

pp. 224

Author(s):

Gemma Alder ◽

Nada Signal ◽

Alain C. Vandal ◽

Sharon Olsen ◽

Mads Jochumsen ◽

...

Keyword(s):

Neural Plasticity ◽

Repeated Measures ◽

Single Pulse ◽

Stroke Recovery ◽

Motor Threshold ◽

Additive Interaction ◽

Post Intervention ◽

Paired Associative Stimulation ◽

Intervention Efficacy ◽

Movement Type

Advances in our understanding of neural plasticity have prompted the emergence of neuromodulatory interventions, which modulate corticomotor excitability (CME) and hold potential for accelerating stroke recovery. Endogenous paired associative stimulation (ePAS) involves the repeated pairing of a single pulse of peripheral electrical stimulation (PES) with endogenous movement-related cortical potentials (MRCPs), which are derived from electroencephalography. However, little is known about the optimal parameters for its delivery. A factorial design with repeated measures delivered four different versions of ePAS, in which PES intensities and movement type were manipulated. Linear mixed models were employed to assess interaction effects between PES intensity (suprathreshold (Hi) and motor threshold (Lo)) and movement type (Voluntary and Imagined) on CME. ePAS interventions significantly increased CME compared to control interventions, except in the case of Lo-Voluntary ePAS. There was an overall main effect for the Hi-Voluntary ePAS intervention immediately post-intervention (p = 0.002), with a sub-additive interaction effect at 30 min’ post-intervention (p = 0.042). Hi-Imagined and Lo-Imagined ePAS significantly increased CME for 30 min post-intervention (p = 0.038 and p = 0.043 respectively). The effects of the two PES intensities were not significantly different. CME was significantly greater after performing imagined movements, compared to voluntary movements, with motor threshold PES (Lo) 15 min post-intervention (p = 0.012). This study supports previous research investigating Lo-Imagined ePAS and extends those findings by illustrating that ePAS interventions that deliver suprathreshold intensities during voluntary or imagined movements (Hi-Voluntary and Hi-Imagined) also increase CME. Importantly, our findings indicate that stimulation intensity and movement type interact in ePAS interventions. Factorial designs are an efficient way to explore the effects of manipulating the parameters of neuromodulatory interventions. Further research is required to ensure that these parameters are appropriately refined to maximise intervention efficacy for people with stroke and to support translation into clinical practice.

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2190 Longitudinal changes in EEG power envelope connectivity are proportional to motor recovery in chronic stroke patients

Journal of Clinical and Translational Science ◽

10.1017/cts.2018.92 ◽

2018 ◽

Vol 2 (S1) ◽

pp. 17-17

Author(s):

Joseph B. Humphries ◽

David T. Bundy ◽

Eric C. Leuthardt ◽

Thy N. Huskey

Keyword(s):

Motor Cortex ◽

Motor Imagery ◽

Stroke Rehabilitation ◽

Brain Computer Interface ◽

Chronic Stroke ◽

Motor Recovery ◽

Stroke Recovery ◽

Computer Interface ◽

Beta Band ◽

Stroke Patients

OBJECTIVES/SPECIFIC AIMS: The objective of this study is to determine the degree to which the use of a contralesionally-controlled brain-computer interface for stroke rehabilitation drives change in interhemispheric motor cortical activity. METHODS/STUDY POPULATION: Ten chronic stroke patients were trained in the use of a brain-computer interface device for stroke recovery. Patients perform motor imagery to control the opening and closing of a motorized hand orthosis. This device was sent home with patients for 12 weeks, and patients were asked to use the device 1 hour per day, 5 days per week. The Action Research Arm Test (ARAT) was performed at 2-week intervals to assess motor function improvement. Before the active motor imagery task, patients were asked to quietly rest for 90 seconds before the task to calibrate recording equipment. EEG signals were acquired from 2 electrodes—one each centered over left and right primary motor cortex. Signals were preprocessed with a 60 Hz notch filter for environmental noise and referenced to the common average. Power envelopes for 1 Hz frequency bands (1–30 Hz) were calculated through Gabor wavelet convolution. Correlations between electrodes were then calculated for each frequency envelope on the first and last 5 runs, thus generating one correlation value per subject, per run. The chosen runs approximately correspond to the first and last week of device usage. These correlations were Fisher Z-transformed for comparison. The first and last 5 run correlations were averaged separately to estimate baseline and final correlation values. A difference was then calculated between these averages to determine correlation change for each frequency. The relationship between beta-band correlation changes (13–30 Hz) and the change in ARAT score was determined by calculating a Pearson correlation. RESULTS/ANTICIPATED RESULTS: Beta-band inter-electrode correlations tended to decrease more in patients achieving greater motor recovery (Pearson’s r=−0.68, p=0.031). A similar but less dramatic effect was observed with alpha-band (8–12 Hz) correlation changes (Pearson’s r=−0.42, p=0.22). DISCUSSION/SIGNIFICANCE OF IMPACT: The negative correlation between inter-electrode power envelope correlations in the beta frequency band and motor recovery indicates that activity in the motor cortex on each hemisphere may become more independent during recovery. The role of the unaffected hemisphere in stroke recovery is currently under debate; there is conflicting evidence regarding whether it supports or inhibits the lesioned hemisphere. These findings may support the notion of interhemispheric inhibition, as we observe less in common between activity in the 2 hemispheres in patients successfully achieving recovery. Future neuroimaging studies with greater spatial resolution than available with EEG will shed further light on changes in interhemispheric communication that occur during stroke rehabilitation.

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Effects of proximal and distal robot-assisted upper limb rehabilitation on chronic stroke recovery

Neurorehabilitation ◽

10.3233/nre-130925 ◽

2013 ◽

Vol 33 (1) ◽

pp. 33-39 ◽

Cited By ~ 21

Author(s):

Stefano Mazzoleni ◽

Patrizio Sale ◽

Marco Franceschini ◽

Samuele Bigazzi ◽

Maria Chiara Carrozza ◽

...

Keyword(s):

Upper Limb ◽

Chronic Stroke ◽

Stroke Recovery ◽

Robot Assisted ◽

Upper Limb Rehabilitation ◽

Limb Rehabilitation

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Bimanual Movements and Chronic Stroke Rehabilitation: Looking Back and Looking Forward

Applied Sciences ◽

10.3390/app112210858 ◽

2021 ◽

Vol 11 (22) ◽

pp. 10858

Author(s):

James H. Cauraugh ◽

Nyeonju Kang

Keyword(s):

Neural Plasticity ◽

Stroke Rehabilitation ◽

Primary Motor Cortex ◽

Supplementary Motor Area ◽

Chronic Stroke ◽

Upper Extremities ◽

Bimanual Movement ◽

Movement Coordination ◽

Bimanual Movements ◽

Motor Actions

Executing voluntary motor actions in the upper extremities after a stroke is frequently challenging and frustrating. Although spontaneous motor recovery can occur, reorganizing the activation of the primary motor cortex and supplementary motor area takes a considerable amount of time involving effective rehabilitation interventions. Based on motor control theory and experience-dependent neural plasticity, stroke protocols centered on bimanual movement coordination are generating considerable evidence in overcoming dysfunctional movements. Looking backward and forward in this comprehensive review, we discuss noteworthy upper extremity improvements reported in bimanual movement coordination studies including force generation. Importantly, the effectiveness of chronic stroke rehabilitation approaches that involve voluntary interlimb coordination principles look promising.

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