Figure 4 - uploaded by Jun-Ding Zhu
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The comparisons of average rectified EMG activities between the experimental conditions. * represents a significant difference.
Source publication
Background:
Several brain regions are activated in response to mirror visual feedback (MVF). However, less is known about how these brain areas and their connectivity are modulated in stroke patients. This study aimed to explore the effects of MVF on brain functional connectivity in stroke patients.
Materials and methods:
We enrolled 15 stroke p...
Context in source publication
Context 1
... comparisons of EMG activities of the affected hand are demonstrated in Figure 4. There was no significant difference in the levels of EMG activities between the Bilateral-No mirror and Bilateral-Mirror conditions (adjusted p = 0.39), suggesting the similar motor performance of the affected hand under the two conditions. ...
Citations
... Interestingly, a series of previous studies on immersive VR in stroke demonstrated ipsi-or contralesional parietal activation owing to the increase in self-awareness of the paretic hand, which leads to an increase in ipsilesional primary motor cortex (M1) activation 16,17 . However, these results may not be generalized to patients with severe stroke since Tai et al. 20 reported a different neurophysiological response to conventional mirror therapy in patients with severe paresis. The patients included in previous studies had mild to moderate hand weakness and stages 3 to 7 according to the Chedoke-McMaster Rating Scale for the hand 16,17 . ...
... In this study, we reported mu-wave suppression in the ipsilesional M1 and parietal lobe elicited by MVF in patients with stroke with severe upper-limb hemiparesis (hand Brunnstrom stage 1-3). This is notable since most previous studies on MVF included patients with mild to moderate-severity stroke 13,16,20,34 . Our data showed that MVF activated the ipsilesional sensorimotor network in patients with stroke with severe paresis, in congruence with Wang et al. 15 They reported ipsilesional activation of the precuneus with fMRI in patients with stroke with severe hemiparesis. ...
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.
Background: This study aimed to investigate 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 patients with chronic stroke. Methods: Fourteen patients with chronic stroke with severe upper limb hemiparesis (Brunnstrom stage of hand 1-3) and 21 healthy controls were included. The participants performed wrist extension tasks with their unaffected wrists (or the dominant side in controls). In the MVF condition, the movement of the affected hand was synchronized with that of the unaffected hand. In contrast, only the movement of the unaffected hand was shown in the no-MVF condition. Electroencephalography was obtained during experiments with two conditions (MVF vs no-MVF). Mu suppression in the bilateral M1 and parietal cortex and mu coherence between the ipsilateral M1 and parietal cortex in each hemisphere and interhemispheric M1 were used for analyses. Results: 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 significant mu suppression was observed in the bilateral M1 (p=0.003 for ipsilesional and p=0.041 for contralesional M1, respectively) and contralesional (contralateral hemisphere to the moving hand) parietal lobes in the healthy controls (p=0.036). The ipsilesional mu coherence between the M1 and parietal cortex in patients with stroke was stronger than that in 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). Conclusion: In patients with stroke, MVF using immersive VR induces mu suppression in the ipsilesional M1 and parietal lobe. Our findings provide evidence of the neural mechanism of MVF using immersive VR and support its application in patients with stroke with severe hemiparesis.
