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Mirror therapy (MT) has been proposed to promote motor recovery post-stroke through activation of mirror neuron system, recruitment of ipsilateral motor pathways, or/and increasing attention toward the affected limb. However, neuroimaging evidence for these mechanisms is still lacking. To uncover the underlying mechanisms, we designed a randomized controlled study and used a voxel-based whole-brain analysis of resting-state fMRI to explore the brain reorganizations induced by MT. Thirty-five stroke patients were randomized to an MT group (n ​= ​16) and a conventional therapy (CT) group (n ​= ​19) for a 4-week intervention. Before and after the intervention, the Fugl-Meyer Assessment Upper Limb subscale (FMA-UL) and resting-state fMRI were collected. A healthy cohort (n ​= ​16) was established for fMRI comparison. The changes in fractional amplitude of low-frequency fluctuation (fALFF) and seed-based functional connectivity were analyzed to investigate the impact of intervention. Results showed that greater FMA-UL improvement in the MT group was associated with the compensatory increase of fALFF in the contralesional precentral gyrus (M1) region and the re-establishment of functional connectivity between the bilateral M1 regions, which facilitate motor signals transmission via the ipsilateral motor pathways from the ipsilesional M1, contralesional M1, to the affected limb. A step-wise linear regression model revealed these two brain reorganization patterns collaboratively contributed to FMA-UL improvement. In conclusion, MT achieved motor rehabilitation primarily by recruitment of the ipsilateral motor pathways. Trial Registration Information: http://www.chictr.org.cn. Unique Identifier. ChiCTR-INR-17013644, submitted on December 2, 2017., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Xiaoli Guo reports financial support was provided by National Natural Science Foundation of China. Li Ding reports financial support was provided by National Natural Science Foundation of China. Jie Jia reports financial support was provided by National Natural Innovation Research Group Project of China. Jie Jia reports financial support was provided by National Natural Integration Project. Li Ding reports financial support was provided by Shanghai Sailing Program. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The efficacy of motor imagery training for motor recovery is well acknowledged, but with substantial inter-individual variability in stroke patients. To help optimize motor imagery training therapy plans and screen suitable patients, this study aimed to explore neuroimaging biomarkers explaining variability in treatment response. Thirty-nine stroke patients were randomized to a motor imagery training group (n = 22, received a combination of conventional rehabilitation therapy and motor imagery training) and a control group (n = 17, received conventional rehabilitation therapy and health education) for 4 weeks of interventions. Their demography and clinical information, brain lesion from structural MRI, spontaneous brain activity and connectivity from rest fMRI, and sensorimotor brain activation from passive motor task fMRI were acquired to identify prognostic factors. We found that the variability of outcomes from sole conventional rehabilitation therapy could be explained by the reserved sensorimotor neural function, whereas the variability of outcomes from motor imagery training + conventional rehabilitation therapy was related to the spontaneous activity in the ipsilesional inferior parietal lobule and the local connectivity in the contralesional supplementary motor area. The results suggest that additional motor imagery training treatment is also efficient for severe patients with damaged sensorimotor neural function, but might be more effective for patients with impaired motor planning and reserved motor imagery., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Mirror visual feedback (MVF) intervention is an adjunctive approach for motor recovery after stroke. It has been hypothesized that MVF can increase visual perception, motor imagery, and attention of/to the hands. However, neuroimaging evidence for this hypothesis is still lacking. In this study, we used a hand mental rotation task and event-related potential (ERP) analysis to explore the effect of MVF intervention on visual perception, motor preparation, and motor imagery of hands. We recruited 46 patients and randomly divided them into a mirror visual feedback group (MG) and a conventional intervention group (CG). By comparing ERP amplitude between the two groups and between before and after the intervention, we found that the N200 component, which was considered to be related to motor preparation, was significantly less negative in the affected hemisphere than that in the unaffected counterpart. After intervention, the N200 amplitude became more negative, reflecting a recovery of motor preparation. Specifically, MG showed a significant effect on the N200 for the hand pictures at large orientations, while the CG showed an effect mainly for the upright hand stimuli. The results suggested an improvement of preparation for motor imagery of complex and precise hand movements after MVF intervention.Clinical Relevance- This study might be helpful for understanding the neural mechanisms of MVF which can help stroke patients regain upper extremity function.

Background: Motor imagery training (MIT) has been widely used to improve hemiplegic upper limb function in stroke rehabilitation. The effectiveness of MIT is associated with the functional neuroplasticity of the motor network. Currently, brain activation and connectivity changes related to the motor recovery process after MIT are not well understood., Aim: We aimed to investigate the neural mechanisms of MIT in stroke rehabilitation through a longitudinal intervention study design with task-based functional magnetic resonance imaging (fMRI) analysis., Methods: We recruited 39 stroke patients with moderate to severe upper limb motor impairment and randomly assigned them to either the MIT or control groups. Patients in the MIT group received 4 weeks of MIT therapy plus conventional rehabilitation, while the control group only received conventional rehabilitation. The assessment of Fugl-Meyer Upper Limb Scale (FM-UL) and Barthel Index (BI), and fMRI scanning using a passive hand movement task were conducted on all patients before and after treatment. The changes in brain activation and functional connectivity (FC) were analyzed. Pearson's correlation analysis was conducted to evaluate the association between neural functional changes and motor improvement., Results: The MIT group achieved higher improvements in FM-UL and BI relative to the control group after the treatment. Passive movement of the affected hand evoked an abnormal bilateral activation pattern in both groups before intervention. A significant Group × Time interaction was found in the contralesional S1 and ipsilesional M1, showing a decrease of activation after intervention specifically in the MIT group, which was negatively correlated with the FM-UL improvement. FC analysis of the ipsilesional M1 displayed the motor network reorganization within the ipsilesional hemisphere, which correlated with the motor score changes., Conclusions: MIT could help decrease the compensatory activation at both hemispheres and reshape the FC within the ipsilesional hemisphere along with functional recovery in stroke patients., (© 2022 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Objectives: In China, Xingnao Kaiqiao (XNKQ) acupuncture has been widely used for stroke treatment. However, its electrophysiological mechanism remains unclear. Hence, this study aims to study how XNKQ acupuncture modulates brain rhythm oscillations of stroke patients, and investigate its correlation with stroke recovery. Design: Randomized control trial. Subjects: Twenty (sub)acute ischemic stroke patients were enrolled and randomly assigned to two groups (an acupuncture group [AG] [n = 10] and a control group [CG] [n = 10]), and four patients (two patients in each group) dropped out of the study. Interventions: All patients received conventional treatments, and the patients in AG received additional XNKQ acupuncture treatment once a day for 10 consecutive days. Outcome measures: Before treatment, 14 days after, and 30 days after treatment onset, their movement impairments and neurologic deficits were measured using the National Institute of Health Stroke Scale (NIHSS), the Fugl-Meyer (FM) Scale, the Modified Rankin Scale (mRS), and the Modified Barthel Index (MBI), and their electroencephalogram data were recorded. Results: Compared with the CG, the AG showed more improvement in FM scores ( p  = 0.02), as well as decreased relative delta power and increased relative alpha power after 2 weeks' treatment. The decrease of the relative delta power and the increase of the relative alpha power in the ipsilesional frontal area were significantly correlated with the FM improvement (F5, F7, FC1, and Fz electrodes, all | r | > 0.517, p  < 0.040). Conclusions: The curative effect of XNKQ acupuncture related to its electrophysiological modulation. This study was registered at the Chinese Clinical Trial Registry (ChiCTR2000038560).

Background . Reorganization in motor areas have been suggested after motor imagery training (MIT). However, motor imagery involves a large-scale brain network, in which many regions, andnot only the motor areas, potentially constitute the neural substrate for MIT. Objective . This study aimed to identify the targets for MIT in stroke rehabilitation from a voxel-based whole brain analysis of resting-state functional magnetic resonance imaging (fMRI). Methods . Thirty-four chronic stroke patients were recruited and randomly assigned to either an MIT group or a control group. The MIT group received a 4-week treatment of MIT plus conventional rehabilitation therapy (CRT), whereas the control group only received CRT. Before and after intervention, the Fugl-Meyer Assessment Upper Limb subscale (FM-UL) and resting-state fMRI were collected. The fractional amplitude of low-frequency fluctuations (fALFF) in the slow-5 band (0.01-0.027 Hz) was calculated across the whole brain to identify brain areas with distinct changes between 2 groups. These brain areas were then targeted as seeds to perform seed-based functional connectivity (FC) analysis. Results . In comparison with the control group, the MIT group exhibited more improvements in FM-UL and increased slow-5 fALFF in the ipsilesional inferior parietal lobule (IPL). The change of the slow-5 oscillations in the ipsilesional IPL was positively correlated with the improvement of FM-UL. The MIT group also showed distinct alternations in FCs of the ipsilesional IPL, which were correlated with the improvement of FM-UL. Conclusions . The rehabilitation efficiency of MIT was associated with increased slow-5 oscillations and altered FC in the ipsilesional IPL. Clinical Trial Registration . http://www.chictr.org.cn . Unique Identifier . ChiCTR-TRC-08003005.

A number of studies have suggested that motor imagery training (MIT) has a positive influence on the upper extremity motor recovery in stroke patients, but little is known about its neural basis. To investigate the cortical motor network plasticity after MIT, 34 chronic hemiplegic subjects with subcortical stroke were recruited and randomly allocated to either the conventional rehabilitation therapy (CRT) or the CRT + MIT. The patients were assessed with the upper limb section of Fugl-Meyer assessment Scale (FM-UL) and resting-state fMRI before and after the 4 weeks of treatment. Seed-based functional connectivity (FC) of the ipsilesional primary motor cortex (M1) and graph-theory based analysis were used to explore the relationships between the motor recovery and reorganization of motor networks. We found that the patients in the MIT group showed more improvement in the FM-UL scores compared with the CRT group. Both groups presented increased inter-hemispheric and decreased intra-hemispheric FC of the ipsilesional M1 after intervention. However, the MIT group showed increased FC of the ipsilesional M1 with the ipsilesional precentral and postcentral gyri, middle cingulate gyrus and supramarginal gyrus after intervention, while the CRT group showed decreased FC in these regions. In addition, the clustering coefficient was significantly increased in the MIT group but not in the CRT group, and the increment of clustering coefficient was significantly positively correlated with improvement of FM-UL scores. Therefore, MIT might contribute to the motor recovery in stroke patients through the following network reorganization, i.e., promoting the efficiency of regional neuronal communication and the reorganization of intrinsic FC of the ipsilesional M1 involving widely distributed motor network in both hemispheres.

Background: Camera technique-based mirror visual feedback (MVF) is an optimal interface for mirror therapy. However, its efficiency for stroke rehabilitation and the underlying neural mechanisms remain unclear., Objective: To investigate the possible treatment benefits of camera-based MVF (camMVF) for priming prior to hand function exercise in subacute stroke patients, and to reveal topological reorganization of brain network in response to the intervention., Methods: Twenty subacute stroke patients were assigned randomly to the camMVF group (MG, N = 10) or a conventional group (CG, N = 10). Before, and after 2 and 4 weeks of intervention, the Fugl-Meyer Assessment Upper Limb subscale (FMA&#95;UL), the Functional Independence Measure (FIM), the modified Ashworth Scale (MAS), manual muscle testing (MMT), and the Berg Balance Scale (BBS) were measured. Resting-state electroencephalography (EEG) signals were recorded before and after 4-week intervention., Results: The MG showed more improvements in the FMA&#95;UL, the FMA&#95;WH (wrist and hand), and the FIM than the CG. The clustering coefficient (CC) of the resting EEG network in the alpha band was increased globally in the MG after intervention but not in the CG. Nodal CC analyses revealed that the CC in the MG tended to increase in the ipsilesional occipital and temporal areas, and the bilateral central and parietal areas, suggesting improved local efficiency of communication in the visual, somatosensory, and motor areas. The changes of nodal CC at TP8 and PO8 were significantly positively correlated with the motor recovery., Conclusions: The camMVF-based priming could improve the motor recovery, daily function, and brain network segregation in subacute stroke patients.

Introduction: As a combination of visual stimulation and motor imagery, mirror visual feedback (MVF) is an effective treatment for motor impairment after stroke; however, few studies have investigated its effects on relevant cognitive processes such as visual perception and motor imagery. Camera-based MVF (camMVF) overcomes the intrinsic limitations of real mirrors and is recognised as an optimal setup. This study aims to investigate the effects of camMVF as an adjunct treatment for stroke patients, compare camMVF outcomes with those of conventional therapy and elucidate neural mechanisms through which MVF influences cognition and brain networks., Methods and Analysis: This will be a multicentre, single-blinded, randomised controlled trial including 90 patients randomised into three groups: camera-based mirror visual feedback intervention group (30), shielded mirror visual feedback intervention group (30) and conventional group (30). Patients in each group will receive a 60 min intervention 5 days per week over 4 weeks. The primary outcome will be the Fugl-Meyer Assessment Upper Limb subscale measurement. Secondary outcomes include the modified Ashworth Scale, Grip Strength test, Modified Barthel Index, Functional Independence Measure, Berg Balance Scale, 10-metre walking test, hand-laterality task and electroencephalography ., Ethics and Dissemination: Ethics approval was granted by the Huashan Hospital Institutional Review Board on 15 March (KY2017-230). We plan to submit the results to a peer-reviewed journal and present them at conferences, rehabilitation forums and to the general public., Trial Registration Number: ChiCTR-INR-17013644; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The intact crossed pathway via which the contralesional hemisphere responds to the ipsilesional somatosensory input has shown to be affected by unilateral stroke. The aim of this study was to investigate the plasticity of the intact crossed pathway in response to different intensities of stimulation in a rodent photothrombotic stroke model. Using optical intrinsic signal imaging, an overall increase of the contralesional cortical response was observed in the acute phase (≤48 hours) after stroke. In particular, the contralesional hyperactivation is more prominent under weak stimulations, while a strong stimulation would even elicit a depressed response. The results suggest a distinct stimulation-response pattern along the intact crossed pathway after stroke. We speculate that the contralesional hyperactivation under weak stimulations was due to the reorganization for compensatory response to the weak ipsilateral somatosensory input.

Plasticity-based spontaneous recovery and rehabilitation intervention of stroke-induced hemianopia have drawn great attention in recent years. However, the underlying neural mechanism remains unknown. This study aims to investigate brain network disruption and reorganization in hemianopia patients due to mild occipital stroke. Resting-state networks were constructed from 12 hemianopia patients with right occipital infarct by partial directed coherence analysis of multi-channel electroencephalograms. Compared with control subjects, the patients presented enhanced connectivity owing to newly formed connections. Compensational connections mostly originated from the peri-infarct area and targeted contralesional frontal, central, and parietal cortices. These new ipsilesional-to-contralesional inter-hemispheric connections coordinately presented significant correlation with the extent of vision loss. The enhancement of connectivity might be the neural substrate for brain plasticity in stroke-induced hemianopia and may shed light on plasticity-based recovery or rehabilitation.

Although motor imagery could improve motor rehabilitation, the detailed neural mechanisms of motor imagery cognitive process of stroke patients, particularly from functional network perspective, remain unclear. This study investigated functional brain network properties in each cognitive sub-stage of motor imagery of stroke patients with ischemic lesion in left hemisphere to reveal the impact of stroke on the cognition of motor imagery. Both stroke patients and control subjects participated in mental rotation task, which includes three cognitive sub-stages: visual stimulus perception, mental rotation and response cognitive process. Event-related electroencephalograph was recorded and interdependence between two different cortical areas was assessed by phase synchronization. Both global and nodal properties of functional networks in three sub-stages were statistically analyzed. Phase synchronization of stroke patients significantly reduced in mental rotation sub-stage. Longer characteristic path length and smaller global clustering coefficient of functional network were observed in patients in mental rotation sub-stage which implied the impaired segregation and integration. Larger nodal clustering coefficient and betweenness in contralesional occipitoparietal and frontal area respectively were observed in patients in all sub-stages. In addition, patients also showed smaller betweenness in ipsilesional central-parietal area in response sub-stage. The compensatory effects on local connectedness and centrality indicated the neuroplasticity in contralesional hemisphere. The functional brain networks of stroke patients demonstrated significant alterations and compensatory effects during motor imagery.

Visual cortical stroke patients may have hemianopia symptom, which affects a number of visual functions. Most studies on hemianopia stroke have mainly focused on cortical activation during visual stimulation, leaving the pattern of functional connectivity between different brain regions uncovered yet. In the present study, we investigate the resting neural networks of hemianopia stroke patients by graph theoretical analysis of functional brain networks constructed with phase synchronization indexes of multichannel electroencephalography (EEG) signals. Our results showed that although the global network topological metrics, i.e., weighted clustering coefficient and characteristic path length of patients and healthy controls are comparable, the left primary visual cortex of patients tend to be less active than that of age-matched healthy subjects. However, hemianopia patients showed greater activation in the ipsilesional (left) temporopolar and orbit frontal areas and the contralesional (right) associative visual cortex. These results may offer new insight into neural substrates of the hemianopia stroke, and the further study of neural plasticity and brain reorganization after hemianopia.

Objective: This study investigated whether cortical synchrony derived from electroencephalography (EEG) in elderly patients is impaired and if the impairment might reflect long-term functional recovery after stroke., Methods: The scalp EEG signals of stroke patients (N=42) were collected within seven days after the onset of stroke and analyzed with phase synchronization (PS). Neurodeficit outcome was scored twice according to the National Institute of Health Stroke Scale (NIHSS): (1) at the same day of EEG recording and (2) two months after stroke. The correlation between cortical synchrony and NIHSS was analyzed., Results: The level of synchronization between lesion and intact areas in the ipsilateral hemisphere was reduced significantly after stroke, while the synchronization among intact areas increased to 114% among the control subjects. Furthermore, the patients with lower inter-hemispheric synchrony after stroke were observed to have a higher NIHSS two months after stroke., Conclusions: Results indicated that the infarct broke down the cortical synchrony networks and affected large-scale neural communication. Inter-hemispheric synchrony was relevant to long-term functional recovery after stroke., Significance: The prognostic value of PS for functional recovery after stroke might be helpful in understanding the alteration of cortical networks after ischemic injury., (Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Stroke has remained as a leading cause of death and neurological disability worldwide in the past decades. Previous structural and functional studies reported little information regarding cortical neural network after stroke. Using the causality measure based on multi-channel electroencephalograph (EEG), i.e. partial directed coherence (PDC) in this paper, we investigated the different network patterns involved in pre-motor and parietal areas (F3, F4, C3, C4, P3 and P4) in three groups of patients who suffered unilateral or bilateral hemispheric stroke in basal ganglia with extension into corona radiate. Compared with the results in the control group, stroke patients showed: 1) more vulnerable long-distance intra- and inter-hemispheric interactions due to the ischemic injury; 2) strengthened short-distance interactions between the central areas in the intact hemisphere with the injured counterpart, which implied a functional compensation after unilateral stroke; 3) more suppression of cortical connections after bilateral hemispheric stroke than those with unilateral stroke. Causal interdependence by PDC analysis provides a new insight of cortical functional network following stroke.

Background: In China, Jin's three-needle acupuncture therapy has been widely used for stroke treatment. However, its mechanism remains unclear. The aim of this study was to investigate the effects of Jin's three-needle acupuncture therapy on stroke patients using multi-channel EEGs. Materials and methods: Fifty stroke patients participated and their EEG signals were recorded before, during, and after acupuncture. Results: Comparing with baseline before acupuncture, the alpha rhythm was significantly increased during the acupuncture needle retention stage and became stronger after removing the needles. The increase of alpha rhythm occurred when inserting and removing the needles, with its high amplitude remaining during retention and after removal of the needles. As the alpha rhythm was significantly correlated with patients' movement and daily-living abilities, the alteration of alpha rhythm during and after acupuncture suggests a possible electrophysiological mechanism of the curative effect of acupuncture for stroke rehabilitation. Conclusion: From the electrophysiological study, Jin's three-needle acupuncture therapy is efficient in stroke patients. [ABSTRACT FROM AUTHOR]

Mirror visual feedback (MVF) is used widely for motor recovery after stroke, but an optimal training setup and systematic procedure are lacking. New optimization strategies have been proposed, one of which is a camera technique. We investigated the effects of a camera-based MVF setup on motor function and motor processes upstream for upper-limb rehabilitation. Seventy-nine stroke patients were assigned randomly to the MVF group (MG; ${N} = {38}$) or conventional group (CG; ${N} = {41}$), which, respectively, received camera-based MVF and dosage-equivalent physiotherapy or/and occupational therapy for 1 h/day and five days/week for four weeks. Two clinical scales were used to quantify the effect of the intervention methods: the Fugl–Meyer assessment-upper limb (FMA-UL) subscale and Barthel index. The hand laterality task was used to evaluate the ability of mental rotation, including the reaction time and accuracy. All measurements were improved significantly for both groups following intervention. FMA-UL was improved significantly in the MG compared with that in the CG. In lateralization tasks, the RT of the MG was significantly shorter than that of the CG at the endpoint. For all patients, judgments for the affected side were significantly slower and less accurate than for the less-affected side. Subgroup analyses suggested greater benefits of motor function, the activities of daily life, and mental rotation were achieved in subacute patients after MVF. A trend toward greater improvements in motor function for patients with severe–moderate motor impairment and patients with right-hemisphere damage were also revealed. Camera-based MVF has improved the motor function and ability of mental rotation for stroke patients, especially for patients in the subacute stage, which indicates the potential to improve motor preparation. Further studies might combine mental rotation with electroencephalography to investigate the neuro-mechanism of MVF. [ABSTRACT FROM AUTHOR]