[REVIEW] Combinations of Stroke Neurorehabilitation to Facilitate Motor Recovery: Perspectives on Hebbian Plasticity and Homeostatic Metaplasticity – Full Text PDF

ABSTRACT

Motor recovery after stroke involves developing new neural connections, acquiring new functions, and compensating for impairments. These processes are related to neural plasticity. Various novel stroke rehabilitation techniques based on basic science and clinical studies of neural plasticity have been developed to aid motor recovery.

Current research aims to determine whether using combinations of these techniques can synergistically improve motor recovery. When different stroke neurorehabilitation therapies are combined, the timing of each therapeutic program must be considered to enable optimal neural plasticity. Synchronizing stroke rehabilitation with voluntary neural and/or muscle activity can lead to motor recovery by targeting Hebbian plasticity. This reinforces the neural connections between paretic muscles and the residual motor area. Homeostatic metaplasticity, which stabilizes the activity of neurons and neural circuits, can either augment or reduce the synergic effect depending on the timing of combination therapy and types of neurorehabilitation that are used. Moreover, the possibility that the threshold and degree of induced plasticity can be altered after stroke should be noted.

This review focuses on the mechanisms underlying combinations of neurorehabilitation approaches and their future clinical applications. We suggest therapeutic approaches for cortical reorganization and maximal functional gain in patients with stroke, based on the processes of Hebbian plasticity and homeostatic metaplasticity. Few of the possible combinations of stroke neurorehabilitation have been 3 tested experimentally; therefore, further studies are required to determine the appropriate combination for motor recovery.

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[REVIEW] Brain-controlled neuromuscular stimulation to drive neural plasticity and functional recovery

Highlights

• Brain-controlled functional electrical stimulation (FES) can restore motor function.
• Appropriately timed neuromuscular electrical stimulation drives plastic changes.
• Site, sign, and magnitude of changes depend on coordination with central activity.
• Hence, brain-controlled FES may cause long-lasting recovery following stroke or SCI.

There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders.

This review addresses the idea that coordinating stimulation with a patient’s voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to match the details of the patient’s voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity.

via Brain-controlled neuromuscular stimulation to drive neural plasticity and functional recovery.

[WEB SITE] GLOREHA supports upper limb rehabilitation

GLOREHA supports upper limb rehabilitation:

• MOBILIZES finger joints: A comfortable and lightweight glove performs all the combinations of joint flexion-extension. If the patient has partial capabilities, he can actively complete his movements.
• STIMULATES neural plasticity: A multi-sensorial stimulation is linked to motor exercises. The therapy includes on screen 3D animation which motivates and involves the patient.
• HELPS THE PATIENT to perform functional exercises: The device leaves the patient’s arm and palm totally free. He can interact with real objects and perform reaching and grasping exercises.

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[ARTICLE] Low frequency repetitive transcranial magnetic stimulation to the non-lesioned hemisphere improves paretic arm reach-to-grasp performance after chronic stroke.

Purpose: To investigate the effect of inhibitory low frequency repetitive Transcranial Magnetic Stimulation (rTMS) applied to the non-lesioned hemisphere on kinematics and coordination of paretic arm reach-to-grasp (RTG) actions in individuals with stroke.

Relevance: This study is designed as a phase I trial to determine the feasibility and efficacy of low frequency rTMS applied to the non-lesioned hemisphere for the recovery of reach-to-grasp actions in individuals with hemiparesis secondary to stroke. The results have important implications for the use of rTMS in parallel with complex paretic arm skill practice.

Participants: Nine adults, anterior circulation unilateral stroke. Their average age was 59 years, the average time since stroke was 4.8 years.

Method and analysis: Two TMS treatments were performed on two separate days: active rTMS and sham rTMS. Cortico-motor excitability (CE) of the non-lesioned hemisphere as well as RTG kinematics of the paretic hand as participants reached for a dowel of 1.2 cm in diameter was assessed before and after the rTMS treatments. In the active condition, rTMS was applied over the “hot spot” of the extensor digitorum communis muscle (EDC) in primary motor cortex (M1) of the non-lesioned hemisphere at 90% resting motor threshold. TMS pulses were delivered at 1 Hz for 20 min. In the sham condition, a sham coil was positioned similar to the active condition; TMS clicking noise was produced but no TMS pulse was delivered.

Dependent measures: CE was measured as peak-to-peak amplitude of the motor evoked potential at 120% of resting motor threshold. RTG kinematics included movement time, peak transport velocity, peak aperture, time of peak transport velocity and time of peak aperture. RTG coordination was captured by cross correlation coefficient between transport velocity and grasp aperture size.

Results: While 1 Hz rTMS applied over non-lesioned M1 significantly decreased the MEP amplitude of non-paretic EDC, sham TMS did not have a significant effect on MEP amplitude. Active rTMS significantly decreased total movement time and increased peak grasp aperture. There were no changes in peak transport velocity or the time of peak transport velocity or the time of peak aperture after application of active rTMS. Additionally, the participants completed RTG actions with a more coordinated pattern after undergoing active rTMS. Following sham TMS, there were no changes in CE, RTG kinematics or coordination. While there were no significant correlation between changes in cortico-motor excitability and RTG kinematics, the decrease in cortico-motor excitability of the non-lesioned hemisphere showed a strong correlation with an increase in cross-correlation coefficient.

Conclusions and implications: The findings demonstrate the feasibility and efficacy of low frequency rTMS applied to the non-lesioned hemisphere for the recovery of reach-to-grasp actions in individuals with hemiparesis secondary to stroke. The inhibitory effect of low frequency rTMS resulted in improved paretic hand reach-to-grasp performance with faster movement time and more coordinated reach-to-grasp pattern. These results have important implications for the use of rTMS for stroke rehabilitation.

Implications for Rehabilitation

• Low frequency repetitive transcranial magnetic stimulation (LF-rTMS) to the non-lesioned hemisphere improves paretic arm reach-to-grasp performance.
• The preliminary results have important implications for the use of LF-rTMS as conjunctive intervention for stroke rehabilitation.

via Low frequency repetitive transcranial magnetic stimulation to the non-lesioned hemisphere improves paretic arm reach-to-grasp performance after chronic stroke, Disability and Rehabilitation: Assistive Technology, Informa Healthcare.

[ARTICLE] Predicting and accelerating motor recovery after stroke

Abstract

Purpose of review: This review presents recent developments in the prediction of motor recovery after stroke; explores whether rehabilitation interventions delivered during the spontaneous recovery process can improve outcomes; and identifies the first trials to focus on the rate rather than extent of motor recovery (Supplementary Digital Content 1).

Recent findings: Two recent studies have attempted to accelerate the rate of motor recovery during the first few weeks after stroke, with neuromodulation techniques designed to facilitate excitability of the ipsilesional motor cortex. One trial using transcranial direct current stimulation was negative, and the other trial using bilateral priming was positive. These contrasting results may be explained by important differences in trial design. This new focus on modifying rate, rather than extent, of motor recovery is in line with accumulating evidence that the motor recovery plateau is largely determined by the extent of damage to descending motor pathways, which is currently untreatable.

Summary: Interventions that facilitate neural plasticity and reorganization may accelerate recovery of motor function during the spontaneous recovery period, without affecting final outcome. This may represent a useful new approach for future trials conducted during rehabilitation at the subacute stage of stroke.

[VIDEO] http://links.lww.com/CONR/A30

via Predicting and accelerating motor recovery after stroke : Current Opinion in Neurology.

[ARTICLE] Virtual reality training improves balance function

Virtual reality is a new technology that simulates a three-dimensional virtual world on a computer and enables the generation of visual, audio, and haptic feedback for the full immersion of users. Users can interact with and observe objects in three-dimensional visual space without limitation. At present, virtual reality training has been widely used in rehabilitation therapy for balance dysfunction. This paper summarizes related articles and other articles suggesting that virtual reality training can improve balance dysfunction in patients after neurological diseases. When patients perform virtual reality training, the prefrontal, parietal cortical areas and other motor cortical networks are activated. These activations may be involved in the reconstruction of neurons in the cerebral cortex. Growing evidence from clinical studies reveals that virtual reality training improves the neurological function of patients with spinal cord injury, cerebral palsy and other neurological impairments. These findings suggest that virtual reality training can activate the cerebral cortex and improve the spatial orientation capacity of patients, thus facilitating the cortex to control balance and increase motion function.

via Virtual reality training improves balance function Mao Y, Chen P, Li L, Huang D – Neural Regen Res.