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.

Objective. Action observation (AO) combined with brain-computer interface (BCI) technology enhances cortical activation. Peripheral electrical stimulation (PES) increases corticospinal excitability, thereby activating brain plasticity. To maximize motor recovery, we assessed the effects of BCI-AO combined with PES on corticospinal plasticity. Approach. Seventeen patients with chronic hemiplegic stroke and 17 healthy subjects were recruited. The participants watched a video of repetitive grasping actions with four different tasks for 15 min: (A) AO alone; (B) AO + PES; (C) BCI-AO + continuous PES; and (D) BCI-AO + triggered PES. PES was applied at the ulnar nerve of the wrist. The tasks were performed in a random order at least three days apart. We assessed the latency and amplitude of motor evoked potentials (MEPs). We examined changes in MEP parameters pre-and post-exercise across the four tasks in the first dorsal interosseous muscle of the dominant hand (healthy subjects) and affected hand (stroke patients). Main results. The decrease in MEP latency and increase in MEP amplitude after the four tasks were significant in both groups. The increase in MEP amplitude was sustained for 20 min after tasks B, C, and D in both groups. The increase in MEP amplitude was significant between tasks A vs. B, B vs. C, and C vs. D. The estimated mean difference in MEP amplitude post-exercise was the highest for A and D in both groups. Significance. The results indicate that BCI-AO combined with PES is superior to AO alone or AO + PES for facilitating corticospinal plasticity in both healthy subjects and patients with stroke. Furthermore, this study supports the idea that synchronized activation of cortical and peripheral networks can enhance neuroplasticity after stroke. We suggest that the BCI-AO paradigm and PES could provide a novel neurorehabilitation strategy for patients with stroke., (© 2022 IOP Publishing Ltd.)

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.

Stroke and traumatic brain injury affect an increasing number of people, many of whom retain permanent damage in cognitive functions. Conventionally, cognitive function has been assessed by a paper-based neuropsychological evaluation. However these test environments differ substantially from everyday life. This problem can be overcome by using virtual reality (VR) to objectively evaluate behaviors and cognitive function in simulated daily activities. With our virtual shopping simulation, we compared people who had undergone a stroke with control participants in an immersive VR program that used a head-mounted display (HMD). We evaluated user satisfaction with the tests, complications, and the user interface. Significant differences were consistently found between the stroke group and the control group for the following tasks: stage 1 performance index, interaction error; stage 2 delayed recognition memory score, attention index; and stage 3 executive index (p < 0.001). Perceptive dysfunction, visuospatial dysfunction, level of computer experience, and level of education affected the performance of the stroke group. The frequency of complications in the stroke group, calculated using the cut-off score for the Simulator Sickness Questionnaire, was 9.6% for nausea, 41.9% for oculomotor complications, and 25.8% for disorientation. The frequency of complications between the stroke and control groups was not significantly different. Thirty-five percent of participants in the stroke group and 13% in the control group reported difficulties with using the joystick. This computer-generated VR-based cognitive test shows promise in assessing cognitive function in patients with stroke. More refinements are needed in the user interface and the projection methods.

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).

Abstract 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.

Abstract: 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 &y& Elsevier]

Neurorehabilitation for stroke is important for upper limb motor recovery. Conventional rehabilitation such as occupational therapy has been used, but novel technologies are expected to open new opportunities for better recovery. Virtual reality (VR) is a technology with a set of informatics that provides interactive environments to patients. VR can enhance neuroplasticity and recovery after a stroke by providing more intensive, repetitive, and engaging training due to several advantages, including: (1) tasks with various difficulty levels for rehabilitation, (2) augmented real-time feedback, (3) more immersive and engaging experiences, (4) more standardized rehabilitation, and (5) safe simulation of real-world activities of daily living. In this comprehensive narrative review of the application of VR in motor rehabilitation after stroke, mainly for the upper limbs, we cover: (1) the technologies used in VR rehabilitation, including sensors; (2) the clinical application of and evidence for VR in stroke rehabilitation; and (3) considerations for VR application in stroke rehabilitation. Meta-analyses for upper limb VR rehabilitation after stroke were identified by an online search of Ovid-MEDLINE, Ovid-EMBASE, the Cochrane Library, and KoreaMed. We expect that this review will provide insights into successful clinical applications or trials of VR for motor rehabilitation after stroke. [ABSTRACT FROM AUTHOR]

Action observation (AO), based on the mirror neuron theory, is a promising strategy to promote motor cortical activation in neurorehabilitation. Brain computer interface (BCI) can detect a user's intention and provide them with brain state-dependent feedback to assist with patient rehabilitation. We investigated the effects of a combined BCI-AO game on power of mu band attenuation in stroke patients. Nineteen patients with subacute stroke were recruited. A BCI-AO game provided real-time feedback to participants regarding their attention to a flickering action video using steady-state visual-evoked potentials. All participants watched a video of repetitive grasping actions under two conditions: (1) BCI-AO game and (2) conventional AO, in random order. In the BCI-AO game, feedback on participants' observation scores and observation time was provided. In conventional AO, a non-flickering video and no feedback were provided. The magnitude of mu suppression in the central motor, temporal, parietal, and occipital areas was significantly higher in the BCI-AO game than in the conventional AO. The magnitude of mu suppression was significantly higher in the BCI-AO game than in the conventional AO both in the affected and unaffected hemispheres. These results support the facilitatory effects of the BCI-AO game on mu suppression over conventional AO. [ABSTRACT FROM AUTHOR]