Search

We investigated the activation pattern of the motor cortex (M1) and parietal cortex during immersive virtual reality (VR)-based mirror visual feedback (MVF) of the upper limb in 14 patients with chronic stroke and severe upper limb hemiparesis and in 21 healthy controls. Participants performed wrist extension with unaffected wrists (dominant side in controls). In the MVF condition, movement of the affected hand was synchronized with that of the unaffected hand. In the no-MVF condition, only the movement of unaffected hand was shown. Mu suppression in bilateral M1 and parietal cortex and mu coherence were analyzed. In patients with stroke, MVF induced significant mu suppression in both the ipsilesional M1 and parietal lobes (p = 0.006 and p = 0.009, respectively), while mu suppression was observed in the bilateral M1 (p = 0.003 for ipsilesional and p = 0.041 for contralesional M1, respectively) and contralesional parietal lobes in the controls (p = 0.036). The ipsilesional mu coherence between the M1 and parietal cortex in patients with stroke was stronger than controls, regardless of MVF condition (p < 0.001), while mu coherence between interhemispheric M1 cortices was significantly weaker in patients with stroke (p = 0.032). Our findings provide evidence of the neural mechanism of MVF using immersive VR in patients with stroke., (© 2023. The Author(s).)

Brain-computer interface (BCI) is a promising technique that enables patients' interaction with computers or machines by analyzing specific brain signal patterns and provides patients with brain state-dependent feedback to assist in their rehabilitation. Action observation (AO) and peripheral electrical stimulation (PES) are conventional methods used to enhance rehabilitation outcomes by promoting neural plasticity. In this study, we assessed the effects of attentional state-dependent feedback in the combined application of BCI-AO with PES on sensorimotor cortical activation in patients after stroke. Our approach involved showing the participants a video with repetitive grasping actions under four different tasks. A mu band suppression (8-13 Hz) corresponding to each task was computed. A topographical representation showed that mu suppression of the dominant (healthy) and affected hemispheres (stroke) gradually became prominent during the tasks. There were significant differences in mu suppression in the affected motor and frontal cortices of the stroke patients. The involvement of both frontal and motor cortices became prominent in the BCI-AO+triggered PES task, in which feedback was given to the patients according to their attentive watching. Our findings suggest that synchronous stimulation according to patient attention is important for neurorehabilitation of stroke patients, which can be achieved with the combination of BCI-AO feedback with PES. BCI-AO feedback combined with PES could be effective in facilitating sensorimotor cortical activation in the affected hemispheres of stroke patients.

This study aimed to investigate the effectiveness of the mobile game-based neuromuscular electrical stimulation (MG-NMES) with assessing usability issues, such as attention and curiosity, and intrinsically interesting issues, which is necessary for successful poststroke rehabilitation. With the conventional NMES (C-NMES) system, the subjects underwent active repetitive cyclic NMES training. For assessment of usability issues, 20 hemiplegic stroke subjects were randomly divided into two groups. The subjects in the MG-NMES group (n = 9) and C-NMES group (n = 11) underwent 20 minutes of training each day for 5 days. We assessed the subjects' attention, curiosity, and intrinsically interesting issues; and using questionnaires they answered questions regarding their expectations of the training outcome after each training session. We found that the subjects in the MG-NMES group maintained their attention and interest for the 5 days, and their curiosity and expectation of a positive training outcome gradually increased as the training proceeded. In contrast, the C-NMES group reported no change in their attention or curiosity, but it was lower than the subjects in the MG-NMES group. In addition, their interest gradually decreased, which may have reduced their expectations of a positive outcome as the sessions progressed. There were no side effects during the training sessions in either group. The MG-NMES training paradigm developed is a new, readily available, and highly motivating MG-NMES training system. Based on the usability test, the reported advantages of the system were improved attention and flow experience during NMES training.

Background: Virtual reality (VR) has the potential to provide intensive, repetitive, and task-oriented training, and game-based therapy can enhance patients' motivation and enjoyment., Objective: The objective of the present study was to develop a mobile game-based upper extremity VR program for patients who have experienced stroke, and to evaluate the feasibility and effectiveness of the program., Methods: This randomized, double-blind, controlled trial included 24 patients with ischemic stroke. The intervention group (n = 12) received 30 min of conventional occupational therapy (OT) and 30 min of the mobile upper extremity rehabilitation program using a smartphone and a tablet PC (MoU-Rehab). The controls (n = 12) received conventional OT alone for 1 h per day. Rehabilitation consisted of 10 sessions of therapy, 5 days per week, for 2 weeks. The outcome measures (Fugl-Meyer Assessment of the upper extremity [FMA-UE], Brunnström stage [B-stage] for the arm and the hand, manual muscle testing [MMT], modified Barthel index [MBI], EuroQol-5 Dimension [EQ-5D], and Beck Depression Inventory [BDI]) were assessed at the beginning and end of treatment, and at 1 month. User satisfaction was evaluated by a questionnaire., Results: A greater improvement in the FMA-UE, B-stage, and MMT was found after treatment with the MoU-Rehab than with conventional therapy. The extent of improvements in the MBI, EQ-5D, and BDI was not significantly different between the two groups. Patients in the experimental group completed the 2-weeks treatment without adverse effects, and they were generally satisfied with MoU-Rehab., Conclusion: This mobile game-based VR rehabilitation program appears to be feasible and effective for promoting upper limb recovery after ischemic stroke.

Background: There is growing evidence that the combination of non-invasive brain stimulation and motor skill training is an effective new treatment option in neurorehabilitation. We investigated the beneficial effects of the application of transcranial direct current stimulation (tDCS) combined with virtual reality (VR) motor training., Methods: In total, 15 healthy, right-handed volunteers and 15 patients with stroke in the subacute stage participated. Four different conditions (A: active wrist exercise, B: VR wrist exercise, C: VR wrist exercise following anodal tDCS (1 mV, 20 min) on the left (healthy volunteer) or affected (stroke patient) primary motor cortex, and D: anodal tDCS without exercise) were provided in random order on separate days. We compared during and post-exercise corticospinal excitability under different conditions in healthy volunteers (A, B, C, D) and stroke patients (B, C, D) by measuring the changes in amplitudes of motor evoked potentials in the extensor carpi radialis muscle, elicited with single-pulse transcranial magnetic stimulation. For statistical analyses, a linear mixed model for a repeated-measures covariance pattern model with unstructured covariance within groups (healthy or stroke groups) was used., Results: The VR wrist exercise (B) facilitated post-exercise corticospinal excitability more than the active wrist exercise (A) or anodal tDCS without exercise (D) in healthy volunteers. Moreover, the post-exercise corticospinal facilitation after tDCS and VR exercise (C) was greater and was sustained for 20 min after exercise versus the other conditions in healthy volunteers (A, B, D) and in subacute stroke patients (B, D)., Conclusions: The combined effect of VR motor training following tDCS was synergistic and short-term corticospinal facilitation was superior to the application of VR training, active motor training, or tDCS without exercise condition. These results support the concept of combining brain stimulation with VR motor training to promote recovery after a stroke.

In this study, the virtual reality (VR) proprioception rehabilitation system was developed for stroke patients to use proprioception feedback in upper limb rehabilitation by blocking visual feedback. To evaluate its therapeutic effect, 10 stroke patients (onset>3 month) trained proprioception feedback rehabilitation for one week and visual feedback rehabilitation for another week in random order. Proprioception functions were checked before, a week after, and at the end of training. The results show the click count, error distance and total error distance among proprioception evaluation factors were significantly reduced after proprioception feedback training compared to visual feedback training (respectively, p=0.005, p=0.001, and p=0.007). In addition, subjects were significantly improved in conventional behavioral tests after training. In conclusion, we showed the effectiveness and possible use of the VR to recover the proprioception of stroke patients., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

We investigated a virtual reality (VR) proprioceptive rehabilitation system that could manipulate the visual feedback of upper-limb during training and could do training by relying on proprioception feedback only. Virtual environments were designed in order to switch visual feedback on/off during upper-limb training. Two types of VR training tasks were designed for evaluating the effect of the proprioception focused training compared to the training with visual feedback. In order to evaluate the developed proprioception feedback virtual environment system, we recruited ten stroke patients (age: 54.7± 7.83years, on set: 3.29± 3.83 years). All patients performed three times PFVE task in order to check the improvement of proprioception function just before training session, after one week training, and after all training. In a comparison between FMS score and PFVE, the FMS score had a significant relationship with the error distance(r = -.662, n=10, p = .037) and total movement distance(r = -.726, n=10, p = .018) in PFVE. Comparing the training effect between in virtual environment with visual feedback and with proprioception, the click count, error distance and total error distance was more reduced in PFVE than VFVE. (Click count: p = 0.005, error distance: p = 0.001, total error distance: p = 0.007). It suggested that the proprioception feedback rather than visual feedback could be effective means to enhancing motor control during rehabilitation training. The developed VR system for rehabilitation has been verified in that stroke patients improved motor control after VR proprioception feedback training.

Background: Several experimental studies in stroke patients suggest that mirror therapy and various virtual reality programs facilitate motor rehabilitation. However, the underlying mechanisms for these therapeutic effects have not been previously described., Objectives: We attempted to delineate the changes in corticospinal excitability when individuals were asked to exercise their upper extremity using a real mirror and virtual mirror. Moreover, we attempted to delineate the role of visual modulation within the virtual environment that affected corticospinal excitability in healthy subjects and stroke patients., Methods: A total of 18 healthy subjects and 18 hemiplegic patients were enrolled into the study. Motor evoked potential (MEP)s from transcranial magnetic stimulation were recorded in the flexor carpi radialis of the non-dominant or affected upper extremity using three different conditions: (A) relaxation; (B) real mirror; and (C) virtual mirror. Moreover, we compared the MEPs from the virtual mirror paradigm using continuous visual feedback or intermittent visual feedback., Results: The rates of amplitude increment and latency decrement of MEPs in both groups were higher during the virtual mirror task than during the real mirror. In healthy subjects and stroke patients, the virtual mirror task with intermittent visual feedback significantly facilitated corticospinal excitability of MEPs compared with continuous visual feedback., Conclusion: Corticospinal excitability was facilitated to a greater extent in the virtual mirror paradigm than in the real mirror and in intermittent visual feedback than in the continuous visual feedback, in both groups. This provides neurophysiological evidence supporting the application of the virtual mirror paradigm using various visual modulation technologies to upper extremity rehabilitation in stroke patients.

In this paper, we propose a system for training of stroke patients with unilateral neglect by using technology of virtual reality (VR). The proposed system is designed to compensate for unilateral neglect. This system contains the calibration of unilateral neglect and the training of this disease. The calibration procedure is implemented by aligning the virtual object at a subjective middle line. The training procedure is implemented by completing the missions that are used to keep the virtual avatar safe during crossing the street in a virtual environment. The results of this study show that the proposed system is effective to train unilateral neglect. The left to right ratio scores extracted from this system gradually decrease as the sessions of training are repeated. To validate the VR system parameters, the parameters are analyzed by correlation with those of traditional unilateral neglect assessment methods (such as the line bisection test and the cancellation test).

Action observation (AO) is a promising strategy for promoting motor function in neural rehabilitation. Recently, brain–computer interface (BCI)-AO game rehabilitation, which combines AO therapy with BCI technology, has been introduced to improve the effectiveness of rehabilitation. This approach can improve motor learning by providing feedback, which can be interactive in an observation task, and the game contents of the BCI-AO game paradigm can affect rehabilitation. In this study, the effects of congruent rather than incongruent feedback in a BCI-AO game on mirror neurons were investigated. Specifically, the mu suppression with congruent and incongruent BCI-AO games was measured in 17 healthy adults. The mu suppression in the central motor cortex was significantly higher with the congruent BCI-AO game than with the incongruent one. In addition, the satisfaction evaluation results were excellent for the congruent case. These results support the fact that providing feedback congruent with the motion of an action video facilitates mirror neuron activity and can offer useful guidelines for the design of BCI-AO games for rehabilitation. [ABSTRACT FROM AUTHOR]