Modulation of brain plasticity in stroke: a novel model for neurorehabilitation

Comparison of the efficacy of different protocols of repetitive transcranial magnetic stimulation and transcranial direct current stimulation on motor function, activities of daily living, and neurological function in patients with early stroke: a systematic review and network meta-analysis

BACKGROUND

The application of transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) in patients with early stroke has recently received considerable attention, but the optimal protocol remains inconclusive. This study intends to evaluate and compare the effects of different protocols of tDCS and rTMS on improving motor function, activities of daily living (ADL), and neurological function in patients with early stroke, and to comprehensively assess their efficacy and safety.

METHODS

MEDLINE, Embase, Cochrane Library, and Web of Science were searched. Risk of bias (RoB) was assessed using the Cochrane Risk of Bias 2.0 tool, and Bayesian NMA was conducted using R4.3.1 and Stata16.

RESULTS

The results of NMA showed that after early intervention, bilateral application of high- and low-frequency rTMS (BL-rTMS) performed best in improving the upper extremity motor function at the end of intervention (SUCRA: 92.8%) and 3 months (SUCRA: 95.4%). Besides, low-frequency rTMS (LF-rTMS) performed best in improving the lower extremity motor function (SUCRA: 67.7%). BL-rTMS was the most effective in ameliorating the ADL at the end of intervention (SUCRA: 100%) and 3 months (SUCRA: 85.6%). In terms of the NIHSS scores, BL-rTMS had the highest probability of being the most effective measure at the end of intervention (SUCRA: 99.7%) and 3 months (SUCRA: 97.05%). Besides, LF-rTMS (0%), 5 Hz-rTMS (0%), and intermittent theta-burst stimulation (iTBS) (0%) all exhibited a good safety profile.

CONCLUSION

BL-rTMS is the optimal stimulation protocol for improving upper extremity motor function, ADL, and neurological function in early stroke, with long-term efficacy.

Resting-state connectivity enhancement in Aphasia patients post-speech therapy: a localization model

Resting-state functional connectivity has become a valuable tool in studying post-stroke aphasia (PSA). However, the specific distribution of increased functional connectivity areas (IFCAs) in PSA patients after speech-language therapy (SLT) remains unclear, particularly compared with the intrinsic brain network (IBN) observed in healthy controls. This study aimed to explore the effects of SLT and spontaneous recovery on functional connectivity changes in the brain. We recruited twenty healthy controls and twelve PSA patients, each of whom underwent one month of SLT. The Chinese version of the Western Aphasia Battery (WAB) was administered to assess language function recovery. The Dice coefficients were calculated between each patient's lesion and the reference lesion, which showed moderate to high intensity. The results revealed a close association between the spatial distribution of IFCAs and improvements in specific language functions. Our findings indicate that the distribution pattern of IFCAs may serve as a significant marker of recovery in PSA patients.

Modulation of Fear Extinction by Non-Invasive Brain Stimulation: Systematic Review and Meta-Analysis

Non-invasive brain stimulation (NIBS) is an emerging treatment for mental disorders that is painlessness and easy to administer. However, its effectiveness for modulating fear extinction requires further elucidation. We searched eight bibliographical databases and identified randomized controlled trials of NIBS and fear extinction in healthy populations. Outcomes were evaluated based on skin conductance responses (SCRs) under three experimental stimuli: threat condition stimulation (CS+), safe condition stimulation (CS-), and their discrimination (CS+ minus CS-). We applied a random-effects model to determine effect sizes (Hedge's g) post-stimulation and assessed article quality using Physiotherapy evidence database (PEDro) scale. Twenty-one studies meeting systematic review criteria were included in this analysis, incorporating 40 independent effect sizes and data from 11 studies (n = 632) in the meta-analysis. Compared with the control group, SCRs in CS+ and discrimination were significantly reducted in the intervention group. Fear extinction was more effective in the 24-h test than immediately after NIBS. In conclusion, NIBS enhanced fear extinction, and the time interval between stimulation and testing may serve as a moderating variable.

Evidence for Intermittent Theta Burst Transcranial Magnetic Stimulation for Dysphagia after Stroke: A Systematic Review and Meta-analysis

Dysphagia is the most common serious complication after stroke, with an incidence of about 37-78%, which seriously affects the independence of patients in daily life and clinical recovery. Repetitive transcranial magnetic stimulation (rTMS), as a non-invasive neuromodulation technique, is an emerging option for post-stroke dysphagia. Theta burst stimulation (TBS) is a new mode of transcranial magnetic stimulation that simulates the frequency of pulses released in the hippocampus.Intermittent theta burst stimulation (iTBS) has been shown to increase cortical excitability and improve swallowing function in patients. Our study sought to summarize existing clinical randomized controlled trials to provide evidence-based medical evidence for the clinical use of iTBS. A computer search was conducted on 4 Chinese (Chinese Biomedical Literature Database, VIP Information Resource System, CNKI, and Wanfang Medical Science) and 4 English (including Cochrane Library, Embase, PubMed, Web of Science) databases to retrieve all randomized controlled trials in Chinese and English that explored the effects of Intermittent Theta Burst Stimulation for post-stroke dysphagia. The retrieval years are from database construction to 23 November 2023. The primary outcome measure was a change in Penetration/Aspiration Scale (PAS), Standardized Swallowing Assessment (SSA) and Functional Oral Intake Scale (FOIS), Secondary outcomes included Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), water-swallowing test (WST) etc. A meta-analysis by Standardized Mean Difference (SMD) and 95% confidence interval (CI) was performed with RevMan 5.3. we appraise risk of bias(RoB) of each study with the Cochrane RoB tool. Detailed instructions for using the Cochrane RoB tool are provided in the Cochrane Handbook for Systematic Reviews of Interventions (The Cochrane Handbook). Nine studies were obtained from eight databases after screening by inclusion and exclusion criteria, 567 patients from 9 studies were included in the meta-analysis, and one study was included in the qualitative analysis due to different control groups. Two of the nine studies had an unclear risk of bias, and four studies were at low risk. The results showed that iTBS significantly improved SSA, PAS, FOIS, and PAS scores in stroke patients compared to the control group(P < 0.05), and promoted swallowing function recovery. Our systematic review provides the first evidence of the efficacy of iTBS in improving dysphagia in stroke patients. However, the number of available studies limits the persuasiveness of the evidence and further validation by additional randomized controlled trials is needed.

Adaptation in the spinal cord after stroke: Implications for restoring cortical control over the final common pathway

Control of voluntary movement is predicated on integration between circuits in the brain and spinal cord. Although damage is often restricted to supraspinal or spinal circuits in cases of neurological injury, both spinal motor neurons and axons linking these cells to the cortical origins of descending motor commands begin showing changes soon after the brain is injured by stroke. The concept of 'transneuronal degeneration' is not new and has been documented in histological, imaging and electrophysiological studies dating back over a century. Taken together, evidence from these studies comports more with a system attempting to survive rather than one passively surrendering to degeneration. There tends to be at least some preservation of fibres at the brainstem origin and along the spinal course of the descending white matter tracts, even in severe cases. Myelin-associated proteins are observed in the spinal cord years after stroke onset. Spinal motor neurons remain morphometrically unaltered. Skeletal muscle fibres once innervated by neurons that lose their source of trophic input receive collaterals from adjacent neurons, causing spinal motor units to consolidate and increase in size. Although some level of excitability within the distributed brain network mediating voluntary movement is needed to facilitate recovery, minimal structural connectivity between cortical and spinal motor neurons can support meaningful distal limb function. Restoring access to the final common pathway via the descending input that remains in the spinal cord therefore represents a viable target for directed plasticity, particularly in light of recent advances in rehabilitation medicine.

Repetitive Transcranial Magnetic Stimulation for the Treatment of Spinal Cord Injury: Current Status and Perspective

Spinal cord injury (SCI) can lead to devastating dysfunctions and complications, significantly impacting patients' quality of life and aggravating the burden of disease. Since the main pathological mechanism of SCI is the disruption of neuronal circuits, the primary therapeutic strategy for SCI involves reconstructing and activating circuits to restore neural signal transmission. Repetitive transcranial magnetic stimulation (rTMS), a noninvasive brain stimulation technique, can modulate the function or state of the nervous system by pulsed magnetic fields. Here, we discuss the basic principles and potential mechanisms of rTMS for treating SCI, including promoting the reconstruction of damaged circuits in the spinal cord, activating reorganization of the cerebral cortex and circuits, modulating the balance of inputs to motoneurons, improving the microenvironment and intrinsic regeneration ability in SCI. Based on these mechanisms, we provide an overview of the therapeutic effects of rTMS in SCI patients with motor dysfunction, spasticity and neuropathic pain. We also discuss the challenges and prospectives of rTMS, especially the potential of combination therapy of rTMS and neural progenitor cell transplantation, and the synergistic effects on promoting regeneration, relay formation and functional connectivity. This review is expected to offer a relatively comprehensive understanding and new perspectives of rTMS for SCI treatment.

Bioinspired Smart Triboelectric Soft Pneumatic Actuator-Enabled Hand Rehabilitation Robot

Quantitative assessment for post-stroke spasticity remains a significant challenge due to the encountered variable resistance during passive stretching, which can lead to the widely used modified Ashworth scale (MAS) for spasticity assessment depending heavily on rehabilitation physicians. To address these challenges, a high-force-output triboelectric soft pneumatic actuator (TENG-SPA) inspired by a lobster tail is developed. The bioinspired TENG-SPA can generate approximately 20 N at 0.1 MPa, providing sufficient stretching force for spastic fingers. The anti-interference, durability, and electrical output characteristics of the TENG-SPA under varying conditions-such as different air pressures, bending frequencies, and simulated spastic finger stretching-are explored, demonstrating TENG-SPA's ability to sense resistance during the stretching process. Furthermore, a TENG-SPA-enabled hand rehabilitation robot system integrated with the convolutional neural network (CNN) is further developed, which is tested in a clinical trial involving 15 stroke patients. The results have demonstrated that a classification accuracy for the levels of finger spasticity reaches 93.3% and the MAS scores predicted by the CNN regression model exhibit a strong linear relationship with the actual MAS (R2 = 0.8451, p < 0.01). This study presents promising potential applications in digital rehabilitation medicine, human-machine interaction, biomedicine, and related fields.

Repetitive Transcranial Magnetic Stimulation for Motor Recovery After Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials With Low Risk of Bias

OBJECTIVES

Repetitive transcranial magnetic stimulation (rTMS) has shown promising results in enhancing motor recovery after stroke, but nuances regarding its use, such as the impact of the type and site of stimulation, are not yet established. We aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) with low risk of bias to investigate the effect of rTMS on motor recovery after both ischemic and hemorrhagic stroke.

MATERIALS AND METHODS

Three databases were searched systematically for all RCTs reporting comparisons between rTMS (including theta-burst stimulation) and either no stimulation or sham stimulation up to August 19, 2022. The primary outcome measure was the Fugl-Meyer Assessment for Upper Extremity (FMA-UE). Secondary outcome measures comprised the Action Research Arm Test, Box and Block Test, Modified Ashworth Scale for the wrist, and modified Rankin Scale (mRS).

RESULTS

A total of 37 articles reporting 48 unique comparisons were included. Pooled mean FMA-UE scores were significantly higher in the experimental group than the control group after intervention (MD = 5.4 [MD = 10.7 after correction of potential publication bias], p < 0.001) and at the last follow-up (MD = 5.2, p = 0.031). On subgroup analysis, the improvements in FMA-UE scores, both after intervention and at the last follow-up, were significant in the acute/subacute stage of stroke (within six months) and for patients with more severe baseline motor impairment. Both contralesional and ipsilesional stimulation yielded significant improvements in FMA-UE at the first assessment after rTMS but not at the last follow-up, while the improvements from bilateral rTMS only achieved statistical significance at the last follow-up. Among the secondary outcome measures, only mRS was significantly improved in the rTMS group after intervention (MD = -0.5, p = 0.013) and at the last follow-up (MD = -0.9, p = 0.001).

CONCLUSIONS

Current literature supports the use of rTMS for motor recovery after stroke, especially when done within six months and for patients with more severe stroke at baseline. Future studies with larger sample sizes may be helpful in clarifying the potential of rTMS in poststroke rehabilitation.

Mechanism of inflammatory response and therapeutic effects of stem cells in ischemic stroke: current evidence and future perspectives

Ischemic stroke is a leading cause of death and disability worldwide, with an increasing trend and tendency for onset at a younger age. China, in particular, bears a high burden of stroke cases. In recent years, the inflammatory response after stroke has become a research hotspot: understanding the role of inflammatory response in tissue damage and repair following ischemic stroke is an important direction for its treatment. This review summarizes several major cells involved in the inflammatory response following ischemic stroke, including microglia, neutrophils, monocytes, lymphocytes, and astrocytes. Additionally, we have also highlighted the recent progress in various treatments for ischemic stroke, particularly in the field of stem cell therapy. Overall, understanding the complex interactions between inflammation and ischemic stroke can provide valuable insights for developing treatment strategies and improving patient outcomes. Stem cell therapy may potentially become an important component of ischemic stroke treatment.

S-Nitrosylation of Dexras1 Controls Post-Stroke Recovery via Regulation of Neuronal Excitability and Dendritic Remodeling

AIMS

Stroke is a major public health concern leading to high rates of death and disability worldwide, unfortunately with no effective treatment available for stroke recovery during the repair phase.

METHODS

Photothrombotic stroke was induced in mice. Adeno-associated viruses (AAV) were microinjected into the peri-infarct cortex immediately after photothrombotic stroke. Grid-walking task and cylinder task were used to assess motor function. Western blotting, Golgi staining, and electrophysiology recordings were performed to uncover the mechanisms.

RESULTS

The ternary complex of neuronal nitric oxide synthase (nNOS), carboxy-terminal PDZ ligand of nNOS (CAPON) and dexamethasone-induced ras protein 1 (Dexras1) is structurally beneficial for S-nitrosylation of Dexras1 (SNO-Dexras1). In our previous study, uncoupling nNOS-CAPON interaction by Tat-CAPON-12C promoted functional recovery after stroke. Here, we show that ischemia elevated the levels of nNOS-Dexras1 complex and SNO-Dexras1 in the peri-infarct cortex in the days 4-10 after stroke induction, and as excepted, Tat-CAPON-12C, a peptide disrupting nNOS-CAPON interaction, significantly reversed these changes. The above information implies that repressed SNO-Dexras1 may mediate functional-promoting effects of Tat-CAPON-12C and SNO-Dexras1 could be the vital molecular substrate for post-stroke functional recovery in the repair phage. Inhibiting the ischemia-induced SNO-Dexras1 by AAV vector-mediated knockdown of Dexras1 or over-expression of dominant negative Dexras1 (Dexras1-C11S) produced sustained recovery of motor function from stroke. In contrast, up-regulation of SNO-Dexras1 by over-expressing Dexras1 worsened stroke outcome. Using electrophysiology recordings, we also observed that silence of Dexras1 in the peri-infarct cortex increased the spike number and the miniature excitatory postsynaptic currents (mEPSCs) frequency, suggesting enhancement of neuronal excitability. In addition, silence of Dexras1 increased dendritic complexity in cultured neuron and more importantly enhanced dendritic spine density in the peri-infarct cortex, implying dendritic remodeling.

CONCLUSION

Thus, inhibition of SNO-Dexras1 positively regulates post-stroke functional recovery via enhanced neuronal excitability and dendritic remodeling. Our results identify that SNO-Dexras1 may serve as a novel target for promoting motor functional restoration from stroke in the delayed phase, shedding light on stroke treatment.

Repetitive Transcranial Magnetic Stimulation Strategies for Poststroke Dysphagia: A Systematic Review and Network Meta-analysis

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is a promising approach in improving swallowing function after stroke. However, comparative efficacy of different rTMS protocols for poststroke dysphagia (PSD) remains unclear.

DATA SOURCES

PubMed, Embase, and Cochrane database were systematically searched for eligible random controlled trials (RCTs) from inception to August 30, 2024.

STUDY SELECTION

RCTs comparing rTMS with control or head-to-head comparisons of 2 rTMS protocols in patients with PSD.

DATA EXTRACTION

Data were extracted by 2 independent reviewers. A network meta-analysis combining direct and indirect evidence was conducted to assess the pooled findings of RCTs with standard mean difference (SMD) with 95% credible interval (CrI).

DATA SYNTHESIS

Eighteen RCTs involving 760 participants (mean age of 62.4 [range 49.7-74.7] years; 45.7% women) were included. Pooled data showed that high frequency (HF)/ipsilesional hemisphere (ipsi-hemi) (SMD, -0.94; 95% CrI, -1.51 to -0.44), HF/bilateral hemisphere (bi-hemi) (SMD, -2.59; 95% CrI, -3.50 to -1.72), HF/ipsilesional cerebellar (ipsi-CRB) (SMD, -0.79; 95% CrI, -1.55 to -0.10), HF/bilateral cerebellar (bi-CRB) (SMD, -1.02; 95% CrI, -1.83 to -0.29), and HF/ipsi-hemi + low frequency (LF)/contralesional hemisphere (contra-hemi) (SMD, -2.72; 95% CrI, -4.12 to -1.41) rTMS all significantly improved swallowing function compared with control. For patients with acute stroke, HF/ipsi-hemi rTMS had a positive effect (SMD, -1.36; 95% CrI, -2.86 to -0.02); in subacute stage, HF/ipsi-hemi + LF/contra-hemi rTMS showed the best efficacy (SMD, -2.68; 95% CrI, -4.26 to -1.26). However, rTMS failed to improve swallowing function in chronic stage.

CONCLUSIONS

This network meta-analysis showed that most of the rTMS protocols (HF/ipsi-hemi, HF/bi-hemi, HF/ipsi-CRB, HF/bi-CRB, and HF/ipsi-hemi + LF/contra-hemi) may improve swallowing function in patients with PSD. The HF/ipsi-hemi rTMS had a positive effect in acute stage and the HF/ipsi-hemi + LF/contra-hemi protocol seemed to have the best efficacy when applied in subacute stroke.

Long-term forced-use therapy after sensorimotor cortex lesions restores contralesional hand function and promotes its preference in Macaca mulatta

Injury to one cerebral hemisphere can result in paresis of the contralesional hand and subsequent preference of the ipsilesional hand in daily activities. However, forced use therapy in humans can improve function of the contralesional paretic hand and increase its use in daily activities, although the ipsilesional hand may remain preferred for fine motor activities. Studies in monkeys have shown that minimal forced use of the contralesional hand, which was the preferred hand prior to brain injury, can produce remarkable recovery of function. Here we tested the hypothesis that long-term forced use of the contralesional hand during the post-lesion period can return it to preferred status. Four rhesus monkeys received tests of hand preference prior to surgical lesions of primary motor cortex, lateral premotor cortex and anterior parietal cortex (F2P2 lesion) contralateral to the preferred hand. Beginning two weeks after the lesion, forced use therapy involving contralateral hand reaches to acquire food targets occurred 3X weekly with at least 300 reaches/session until 24 weeks post-lesion. Despite initial paresis of the contralesional hand, its manipulation skill returned to near pre-lesion levels or higher and all four monkeys returned to a contralesional hand preference late in the post-lesion period. Favorable reorganization of spared cortical and subcortical neural networks may promote recovery of hand function and preference. These results have relevance for the use of extensive forced-use therapy in humans who experience unilateral periRolandic injury to potentially support better recovery of contralesional hand function.

Motor and parietal cortex activity responses to mirror visual feedback in patients with subacute stroke: An EEG study

Objective

To elucidate the immediate electrophysiological effects of mirror visual feedback (MVF) combined with or without touch task in subacute stroke.

Methods

Subacute stroke patients and healthy controls were recruited to participate in four grasping tasks (MVF or no MVF, combined with rubber ball or no ball) under electroencephalogram (EEG) monitoring. Event-related desynchronization (ERD) /event-related synchronization (ERS) and the lateralization index (LI) were utilized to observe the electrophysiological effects.

Results

MVF reduced ERD suppression in the contralateral primary motor cortex (M1) of stroke patients. This reduction was observed in the low mu band for the contralateral parietal cortex during pure MVF. The laterality effects in the low mu band under MVF was noted in M1 for stroke patients and in the parietal cortex for all participants.

Conclusions

MVF inhibits the excitability of the contralateral M1 for subacute stroke. MVF inhibit activities in the contralateral M1 and parietal cortex, and reestablished hemispheric balance in the low mu band.

Significance

MVF has an instantaneous effect on subacute stroke by inhibiting the excitability of the contralateral sensorimotor cortex. The attenuated ERD in the low mu band in contralateral M1 and parietal cortex may serve as biomarkers of MVF for stroke rehabilitation.

Noninvasive brain stimulation to improve motor outcomes after stroke

PURPOSE OF REVIEW

This review highlights recent developments in noninvasive brain stimulation (NIBS) techniques and applications for improving motor outcomes after stroke. Two promising areas of development relate to deep brain neuromodulation and the use of single-pulse transcranial magnetic stimulation (TMS) within a prediction tool for predicting upper limb outcome for individual patients.

RECENT FINDINGS

Systematic reviews highlight the inconsistent effect sizes of interventional NIBS for motor outcome after stroke, as well as limited evidence supporting the interhemispheric competition model. To improve the therapeutic efficacy of NIBS, studies have leveraged metaplasticity and priming approaches. Transcranial temporal interference stimulation (tTIS) and low-intensity focused ultrasound stimulation (LIFUS) are emerging NIBS techniques with potential for modulating deeper brain structures, which may hold promise for stroke neurorehabilitation. Additionally, motor evoked potential (MEP) status obtained with single-pulse TMS is a prognostic biomarker that could be used to tailor NIBS for individual patients.

SUMMARY

Trials of interventional NIBS to improve stroke outcomes may be improved by applying NIBS in a more targeted manner. This could be achieved by taking advantage of NIBS techniques that can be targeted to deeper brain structures, using biomarkers of structural and functional reserve to stratify patients, and recruiting patients in more homogeneous time windows.

Characteristic brain functional activation and connectivity during actual and imaginary right-handed grasp

We used 34-channel functional near infrared spectroscopy to investigate and compare changes in oxyhemoglobin concentration of brain networks in bilateral prefrontal cortex, sensorimotor cortex, and occipital lobe of 22 right-handed healthy adults during executive right-handed grasp (motor execution task) and imagined right-handed grasp (motor imagery task). Then calculated lateral index and functional contribution degree, and measured functional connectivity strength between the regions of interest. In the motor executive block task, there was a significant increase in oxyhemoglobin concentration in regions of interest except for right occipital lobe (P<0.05), while in the motor imagery task, all left regions of interest's oxyhemoglobin concentration increased significantly (P<0.05). Except the prefrontal cortex in motor executive task, the left side of the brain was dominant. Left sensorimotor cortex played a major role in these two tasks, followed by right sensorimotor cortex. Among all functional contribution degree, left sensorimotor cortex, right sensorimotor cortex and left occipital lobe ranked top three during these tasks. In continuous acquisition tasks, functional connectivity on during motor imagery task was stronger than that during motor executive task. Brain functions during two tasks of right-hand grasping movement were partially consistent. However, the excitability of brain during motor imagery was lower, and it was more dependent on the participation of left prefrontal cortex, and its synchronous activity of the whole brain was stronger. The trend of functional contribution degree was basically consistent with oxyhemoglobin concentration and lateral index, and can be used as a novel index to evaluate brain function. [ChiCTR2200063792 (2022-09-16)].

Altered Corticospinal and Intracortical Excitability After Stroke: A Systematic Review With Meta-Analysis

BACKGROUND

Intracortical inhibitory/faciliatory measures are affected after stroke; however, the evidence is conflicting.

OBJECTIVE

This meta-analysis aimed to investigate the changes in motor threshold (MT), motor evoked potential (MEP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF), and identify sources of study variability using a machine learning approach.

METHODS

We identified studies that objectively evaluated corticospinal excitability and intracortical inhibition/facilitation after stroke using transcranial magnetic stimulation. Pooled within- (ie, affected hemisphere [AH] vs unaffected hemisphere [UH]) and between-subjects (ie, AH and UH vs Control) standardized mean differences were computed. Decision trees determined which factors accurately predicted studies that showed alterations in corticospinal excitability and intracortical inhibition/facilitation.

RESULTS

A total of 35 studies (625 stroke patients and 328 healthy controls) were included. MT was significantly increased and MEP was significantly decreased (ie, reduced excitability) in the AH when compared with the UH and Control (P < .01). SICI was increased (ie, reduced inhibition) for the AH when compared with the UH, and for the AH and UH when compared with Control (P < .001). ICF was significantly increased (ie, increased facilitation) in the AH when compared with UH (P = .016) and decreased in UH when compared with Control (P < 0.001). Decision trees indicated that demographic and methodological factors accurately predicted (73%-86%) studies that showed alterations in corticospinal and intracortical excitability measures.

CONCLUSIONS

The findings indicate that stroke alters corticospinal and intracortical excitability measures. Alterations in SICI and ICF may reflect disinhibition of the motor cortex after stroke, which is contrary to the notion that stroke increases inhibition of the affected side.

Corticospinal and corticoreticulospinal projections have discrete but complementary roles in chronic motor behaviors after stroke

After corticospinal tract (CST) stroke, several motor deficits can emerge in the upper extremity (UE), including diminished muscle strength, motor control, and muscle individuation. Both the ipsilesional CST and contralesional corticoreticulospinal tract (CReST) innervate the paretic UE, but their relationship to motor behaviors after stroke remains uncertain. In this cross-sectional study of 14 chronic stroke and 27 healthy subjects, we examined two questions: whether the ipsilesional CST and contralesional CReST differentially relate to chronic motor behaviors in the paretic arm and hand and whether the severity of motor deficits differs by proximal versus distal location. In the paretic biceps and first dorsal interosseous muscles, we used transcranial magnetic stimulation to measure the projection strengths of the ipsilesional CST and contralesional CReST. We also used quantitative testing to measure strength, motor control, and muscle individuation in each muscle. We found that stroke subjects had muscle strength comparable to healthy subjects but poorer motor control and muscle individuation. In both paretic muscles, stronger ipsilesional CST projections related to better motor control, whereas stronger contralesional CReST projections related to better muscle strength. Stronger CST projections related to better individuation in the biceps alone. The severity of motor control and individuation deficits was comparable in the arm and hand. These findings suggest that the ipsilesional CST and contralesional CReST have specialized but complementary roles in motor behaviors of the paretic arm and hand. They also suggest that deficits in motor control and muscle individuation are not segmentally biased, underscoring the functional extent and efficacy of these pathways.NEW & NOTEWORTHY The corticospinal (CST) and corticoreticulospinal (CReST) tracts are two major descending motor pathways. We examined their relationships to motor behaviors in paretic arm and hand muscles in chronic stroke. Stronger ipsilesional CST projections related to better motor control, whereas stronger contralesional CReST projections related to better muscle strength. Stronger CST projections are also uniquely related to better biceps individuation. These findings support the notion of specialized but complementary contributions of these pathways to human motor function.

The effectiveness of theta burst stimulation for motor recovery after stroke: a systematic review

BACKGROUND

Stroke is the second leading cause of death and the third leading cause of disability worldwide. Motor dysfunction is a common sequela, which seriously affects the lives of patients. Theta burst stimulation (TBS) is a new transcranial magnetic therapy for improving motor dysfunction after stroke. However, there remains a lack of studies on the mechanism, theoretical model, and effectiveness of TBS in improving motor dysfunction following stroke.

OBJECTIVE

This paper provides a comprehensive overview and assessment of the current impact of TBS on motor rehabilitation following stroke and analyzes potential factors contributing to treatment effect disparities. The aim is to offer recommendations for further refining the TBS treatment approach in subsequent clinical studies while also furnishing evidence for devising tailored rehabilitation plans for stroke patients.

METHODS

This study was conducted following PRISMA guidelines. PubMed, Embase, Web of Science, and the Cochrane Library were searched systematically from the establishment of the database to February 2024. Relevant studies using TBS to treat patients with motor dysfunction after stroke will be included. Data on study characteristics, interventions, outcome measures, and primary outcomes were extracted. The Modified Downs and Black Checklist was used to assess the potential bias of the included studies, and a narrative synthesis of the key findings was finally conducted.

RESULTS

The specific mechanism of TBS in improving motor dysfunction after stroke has not been fully elucidated, but it is generally believed that TBS can improve the functional prognosis of patients by regulating motor cortical excitability, inducing neural network reorganization, and regulating cerebral circulation metabolism. Currently, most relevant clinical studies are based on the interhemispheric inhibition model (IHI), the vicariation model, and the bimodal balance-recovery model. Many studies have verified the effectiveness of TBS in improving the motor function of stroke patients, but the therapeutic effect of some studies is controversial.

CONCLUSION

Our results show that TBS has a good effect on improving motor function in stroke patients, but more large-scale, high-quality, multicenter studies are still necessary in the future to further clarify the mechanism of TBS and explore the optimal TBS treatment.

Enhancement of Cognitive Function in Rats with Vascular Dementia Through Modulation of the Nrf2/GPx4 Signaling Pathway by High-Frequency Repetitive Transcranial Magnetic Stimulation

Repetitive transcranial magnetic stimulation (rTMS) represents a non-invasive therapeutic modality acknowledged for augmenting neurological function recovery following stroke. Nonetheless, uncertainties remain regarding its efficacy in promoting cognitive function recovery in patients diagnosed with vascular dementia (VD). In this study, VD was experimentally induced in a rat model utilizing the bilateral common carotid artery occlusion method. Following a recuperation period of seven days, rats were subjected to high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) at a frequency of 10 Hz. Cognitive function was assessed utilizing the Morris water maze test, and the levels of IL-6, TNF-alpha, SOD, GSH, MDA, and Fe2+ in cerebral tissue were quantitatively analyzed through enzyme-linked immunosorbent assay. Moreover, the gene and protein expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione peroxidase 4 (GPx4) were meticulously investigated via quantitative polymerase chain reaction (qPCR) and Western blotting techniques. The use of HF-rTMS notably augmented cognitive function in rats with VD, concomitantly reducing neuroinflammation, oxidative stress, and ferroptosis within the brain. The group subjected to HF-rTMS demonstrated an increase in the levels of both proteins and genes associated with Nrf2 and GPx4, in comparison to the VD group. These results highlight the potential of HF-rTMS treatment in enhancing cognitive function in rats diagnosed with VD through the modulation of the Nrf2/GPx4 signaling pathway. This modulation, in turn, mitigates processes linked with neuroinflammation, oxidative stress, and ferroptosis. Nevertheless, additional studies are essential to comprehensively elucidate the underlying mechanisms and clinical implications of HF-rTMS treatment in the treatment of VD.

Hypoxic postconditioning modulates neuroprotective glial reactivity in a 3D cortical ischemic-hypoxic injury model

Stroke remains one of the major health challenges due to its high rates of mortality and long-term disability, necessitating the development of effective therapeutic treatment. This study aims to explore the neuroprotective effects of hypoxic postconditioning (HPC) using a cell-based 3D cortical ischemic-hypoxic injury model. Our model employs murine cells to investigate HPC-induced modulation of glial cell reactivity and intercommunication post-oxygen-glucose deprivation-reoxygenation (OGD-R) injury. We found that a single HPC session (1HPC) provided the most significant neuroprotection post-OGD-R compared to multiple intermittent hypoxic treatments, evidenced by improved spheroidal structure, enhanced cell survival and reduced apoptosis, optimal modulation of neuronal phenotypes, dampened ischemic responses, and augmented neurite outgrowth of spheroids. Furthermore, 1HPC suppressed both pro-inflammatory A1 and anti-inflammatory A2 astrocyte phenotypes despite the induction of astrocyte activation while reducing microglial activation with inhibited M1 and M2 reactive states. This was accompanied by a decrease in gene expression of the pro-inflammatory cytokines essential to microglia-astrocyte signaling, collectively suggesting a shift of glial cells away from their traditional reactive states for neuroprotection. This study highlights the potential of 1HPC as a novel therapeutic intervention for ischemic injury via the modulation of neuroprotective glial reactivity. Moreover, the 3D cortical ischemic-hypoxic injury model employed here holds enormous potential serving as a disease model to further elucidate the underlying mechanism of HPC, which can also extend to the applications in brain regeneration, drug development, and the modeling of neural diseases.

Evidence that robot-assisted gait training modulates neuroplasticity after stroke: An fMRI pilot study based on graph theory analysis

OBJECTIVES

To investigate alterations of whole-brain network after stroke and therapeutic mechanisms of robot-assisted gait training (RAGT).

METHODS

21 stroke patients and 20 healthy subjects were enrolled, with the stroke patients randomized to either control group (n = 11) or robot group (n = 10), and resting-state functional magnetic resonance imaging data were collected. The global network metrics were obtained using graph theory analysis and compared between stroke patients and healthy subjects, and the effect of the RAGT on the whole-brain networks was explored.

RESULTS

Compared to healthy subjects, area under the curve (AUC) for small-worldness (σ), clustering coefficient (Cp), global efficiency (Eg) and mean local efficiency (Eloc) were significantly lower in stroke patients, whereas AUC for characteristic path length (Lp) were significantly higher. Compared with the control group, patients in robot group showed significant improvement in lower limb motor function, balance function and walking function after intervention, with a significant reduction in the AUC of Cp. Moreover, the improvement of walking function was positively correlated with the changes of AUC of σ and Eg, and negatively correlated with the changes of AUC of Cp.

CONCLUSIONS

Small-worldness and network efficiency were significantly reduced after stroke, whereas RAGT decreased characteristic path length and promoted normalization of the whole-brain network, and this change was associated with improvement in walking function. Our findings reveal the mechanism by which RAGT regulates network reorganization and neuroplasticity after stroke.

Effect of Dual-Site Non-Invasive Brain Stimulation on Upper-Limb Function After Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Non-invasive brain stimulation (NIBS) has attracted significant attention as it has been proven to be effective in facilitating upper limb motor recovery in patients with stroke. This meta-analysis evaluates the efficacy of dual-site non-invasive brain stimulation (DS-NIBS) in improving upper extremity motor function after stroke.

METHODS

A PRISMA systematic search was conducted for randomized controlled trials. Two authors independently extracted data, and the quality of included studies was assessed.

RESULTS

Ten studies were included in the current review. DS-NIBS demonstrated a significant effect on upper extremity motor function impairment. However, only two studies showed no clear effects of DS-tDCS on upper extremity motor function after stroke. Due to the limited number of studies, the effects of DS-NIBS remain inconclusive.

FINDING

This review found evidence for the relatively higher efficacy of DS-NIBS on post-stroke upper extremity motor function impairment, compared to the sham and SS-NIBS. Additionally, DS-TMS was found to generate better improvement than DS-tDCS.

A Literature Review on Optimal Stimulation Parameters of Transcranial Direct Current Stimulation for Motor Recovery After Stroke

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique with potential in stroke rehabilitation by modulating cortical excitability. However, the optimal parameters, including electrode placement, current intensity, stimulation duration, and electrode size, remain poorly understood, and the interactions among these factors contribute to mixed results in motor recovery post-stroke. This review explores the various stimulation parameters and their impact on enhancing corticospinal excitability (CSE) and motor function recovery. Different electrode placement (montages), such as anodal, cathodal, and bi-hemispheric stimulation, have demonstrated varying effectiveness in restoring motor function. Bihemispheric stimulation demonstrated a larger effect size compared to other unihemispheric (anodal or cathodal) stimulation; however, its relative superiority remains inconclusive. Inter-individual anatomical variations, such as skull thickness, lesion location, and cortical atrophy, can affect tDCS outcomes, highlighting the need for personalized electrode placement guided by computational modeling based on brain imaging. Furthermore, stimulation intensity, typically 1-2 mA, exhibited nonlinear effects on CSE, contrasting with the dose-response relationships observed in earlier studies. Stimulation duration is also critical, with evidence suggesting that prolonged stimulation may reverse excitability-enhancing effects beyond a certain threshold. While smaller electrodes enhance focality, an appropriately sized electrode is necessary to effectively modulate electrical activity in the target region, with evidence suggesting a dose-response relationship between electrode size and motor recovery. Overall, the interplay among these parameters underscores the need for personalized and optimized tDCS protocols to achieve consistent motor recovery in stroke patients. Future research should focus on refining these parameters to maximize the therapeutic benefits of tDCS.

Effects of low-frequency rTMS combined with speech and language therapy on Broca's aphasia in subacute stroke patients

Introduction

Broca's aphasia is a crushing syndrome after stroke. Although there are multiple therapies, the recovery of a considerable number of patients is still not ideal. Repetitive transcranial magnetic stimulation (rTMS) combined with speech and language therapy has been a promising combination regimen in recent years. However, the efficacy and persistent effects thereof remain unclear. We aimed to determine the immediate and long-term effects of rTMS combined with speech and language therapy on subacute stroke patients with Broca's aphasia and explore relevant mechanisms in the picture-naming task via functional near-infrared spectroscopy (fNIRS).

Materials and methods

This was a prospective clinical study. In accordance with the inclusion criteria, 18 patients with post-stroke were recruited and randomly divided into either the rTMS group or the sham-rTMS group. Patients in both groups received low-frequency rTMS therapy for 20 min a day and then speech and language therapy for 30 min a day, 5 days a week, for a total of 4 weeks. Two groups of patients underwent the Western Aphasia Battery Revised (WAB-R), the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39), and non-language-based cognitive assessment (NLCA) before treatment and at 2 weeks, 4 weeks, and 3 months after treatment. Meanwhile, we collected fNIRS task state data while naming images before and after 4 weeks of treatment. The primary outcome was WAB-R changes. The secondary outcomes include the SAQOL-39, NLCA, as well as the difference in activation status of brain regions in the cortical language function network.

Results

For the index scores of the two groups, the results of repeated-measures ANOVA indicated an increasing trend at three time points, i.e., after 2 weeks of treatment, 4 weeks after treatment, and 3 months after the end of treatment (p < 0.001); in terms of intergroup effects, there was a statistically significant difference between the two groups in WAB naming scores (F = 4.865, p = 0.042); and the aphasia quotient (AQ), listening comprehension, and naming scores of the two groups had interactive effects (FAQ = 11.316, PAQ = 0.000; F listening = 8.205, P listening = 0.002; F naming = 27.46, P naming = 0.000). Independent sample t-tests also showed that until 4 weeks after the end of treatment, there were significant differences in information volume and naming scores between the two groups (t information = 2.352, P information = 0.032; t naming = 3.164, P naming = 0.006). Three months after the end of treatment, there were significant differences in information volume, naming, AQ and repetition scores (t information = 2.824, P information = 0.012; t naming = 5.090, P naming = 0.000; tAQ = 2.924, PAQ = 0.010; t repetition = 2.721, P repetition = 0.015). In the picture-naming task, fNIRS analysis found that in the rTMS group after treatment, the activation in the left superior temporal gyrus (STG), middle temporal gyrus (MTG), premotor cortex (PM), supplementary motor area (SMA), pars triangularis Broca's area, and dorsolateral prefrontal lobe (DLPFC) decreased (p < 0.05).

Conclusion

The language function of patients was improved after 4 weeks of treatment, and there was a long-term effect (3 months follow-up), especially in naming gains. Moreover, by analyzing cortical activation during a picture-naming task with fNIRS, we found that rTMS could downgrade the activation level in the left MTG, STG, PM and SMA, DLPFC, and pars triangularis Broca's area, whereas the sham-rTMs group only showed downgraded activation levels in the right PM and SMA. This demonstrates the unique mechanism of rTMS.Clinical trial registration: ChiCTR.org.cn, identifier, ChiCTR2300067703.

Dual-tDCS Ameliorates Cerebral Injury and Promotes Motor Function Recovery via cGAS-STING Signaling Pathway in a Rat Model of Ischemic Stroke

Ischemic stroke is one of the leading causes of death and disability. Dual transcranial direct current stimulation (dual-tDCS) is a promising intervention to treat ischemic stroke, but its efficacy and underlying mechanism remain to be verified. Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has recently emerged as a key mediator in cerebral injury. However, little is known about the effect of cGAS-STING on neuronal damage in ischemic stroke, and it remains to be studied whether the cGAS-STING pathway is involved in tDCS intervention for ischemic stroke. Therefore, we aimed to investigate whether dual-tDCS can alleviate ischemic brain injury in a rat model of ischemic stroke and if so, whether via cGAS-STING pathway. Middle cerebral artery occlusion (MCAO) was employed to induce a rat model of ischemic stroke. Male SD rats weighing 250-280 g were randomly assigned to the Sham, MCAO, Dual-tDCS, Dual-tDCS + RU.521, and Dual-tDCS + 2'3'-cGAMP groups, with 10 rats in each group completing the experiment. Behavioral, morphological, MRI, and molecular biological methods were performed. We found that the cGAS-STING pathway was activated and expressed in neurons after MCAO. Dual-tDCS improved motor function and infarct volume, inhibited neuronal apoptosis, promoted the expression of neurotrophins (BDNF and NGF), CD31, and VEGF, and suppressed inflammation reaction after MCAO via the cGAS-STING pathway. Taken together, dual-tDCS may improve MCAO-induced brain injury and promote the recovery of motor function, resulting from the inhibition of neuronal apoptosis and inflammation reaction, as well as promotion of the expression of nerve plasticity- and angiogenesis-related proteins, via cGAS-STING pathway.

Effects of low frequency repetitive transcranial magnetic stimulation on motor recovery in subacute stroke patients with different motor evoked potential status: a randomized controlled trial

Objectives

To explore the effects of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on motor function and cortical excitability in stroke patients with different motor evoked potential (MEP) status.

Methods

A total of 80 stroke patients were enrolled in this randomized controlled trial and divided into two groups according to MEP status (- or +) of lesioned hemisphere. Then, each group was randomly assigned to receive either active or sham LF-rTMS. In addition to conventional rehabilitation, all participants received 20 sessions of rTMS at 1 Hz frequency through the active or the sham coil over 4 weeks. Fugl-Meyer Assessment (FMA), National Institutes of Health Stroke Scale (NIHSS), Shoulder Abduction Finger Extension (SAFE) and Barthel Index (BI), bilateral resting motor threshold (rMT), amplitude of Motor evoked potential (MEP) and Central Motor Conduction Time (CMCT), and Interhemispheric asymmetry (IHA) were blindly assessed at baseline, 4 weeks and 8 weeks after treatment, respectively.

Results

At 4 weeks after intervention, FMA and NIHSS changed scores in 1 Hz MEP(+) group were significantly higher than those in the other three groups (p < 0.001). After receiving 1 Hz rTMS, stroke patients with MEP(+) showed significant changes in their bilateral cortical excitability (p < 0.05). At 8 weeks after intervention, 1 Hz MEP(+) group experienced higher changes in NIHSS, FMA, SAFE, and BI scores than other groups (p < 0.001). Furthermore, 1 Hz rTMS intervention could decrease unaffected cortical excitability and enhance affected cortical excitability of stroke patients with MEP(+) (p < 0.05). The correlation analysis revealed that FMA motor change score was associated with decreased unaffected MEP amplitude (r = -0.401, p = 0.010) and decreased affected rMT (r = -0.584, p < 0.001) from baseline, which was only observed in the MEP(+) group.

Conclusion

The effects of LF-rTMS on motor recovery and cortical excitability were more effective in stroke patients with MEP than those with no MEP.

Combining Transcranial Direct Current Stimulation With Hand Robotic Rehabilitation in Chronic Stroke Patients: A Double-Blind Randomized Clinical Trial

OBJECTIVE

This study aimed to assess the impact of combining transcranial direct current stimulation with end-effector robot-assisted treatment on upper limb function, spasticity, and hand dexterity in chronic stroke patients.

DESIGN

This was a prospective, double-blind randomized trial with 20 equally allocated stroke patients. The experimental group received dual transcranial direct current stimulation (anode over affected M1, cathode over contralateral M1) alongside robot-assisted treatment, while the control group received sham transcranial direct current stimulation with the same electrode placement + robot-assisted treatment. Each patient underwent 20 combined transcranial direct current stimulation and robot-assisted treatment sessions. The primary outcome measure was the Fugl-Meyer Upper Limb motor score, with secondary outcomes including AMADEO kinematic measures, Action Research Arm Test, and Functional Independence Measure. Assessments were conducted at baseline, after rehabilitation, and 3 mos later.

RESULTS

Combining bilateral transcranial direct current stimulation with robot-assisted treatment did not yield additional improvements in Fugl-Meyer Upper Limb motor score, Functional Independence Measure, or Action Research Arm Test scores among stroke patients. However, the real transcranial direct current stimulation group showed enhanced finger flexion in the affected hand based on AMADEO kinematic measures.

CONCLUSIONS

The addition of transcranial direct current stimulation to robot-assisted treatment did not result in significant overall functional improvements in chronic stroke patients. However, a benefit was observed in finger flexion of the affected hand.

Curcumin loaded hydrogel with double ROS-scavenging effect regulates microglia polarization to promote poststroke rehabilitation

Cyclodextrins are used to include curcumin to form complex, which is subsequently loaded into a reactive oxygen species (ROS) responsive hydrogel (Cur gel). This gel exhibits a dual ROS scavenging effect. The gel can neutralize extracellular ROS to lead to a ROS-sensitive curcumin release. The released curcumin complex can eliminate intracellular ROS. Furthermore, the Cur gel effectively downregulates the expression of CD16 and IL-1β while upregulating CD206 and TGF-β in oxygen and glucose-deprived (OGD) BV2 cells. Additionally, it restores the expression of synaptophysin and PSD95 in OGD N2a cells. Upon injection into the stroke cavity, the Cur gel reduces CD16 expression and increases CD206 expression in the peri-infarct area of stroke mice, indicating an in vivo anti-inflammatory polarization of microglia. Colocalization studies using PSD95 and VGlut-1 stains, along with Golgi staining, reveal enhanced neuroplasticity. As a result, stroke mice treated with the Cur gel exhibit the most significant motor function recovery. Mechanistic investigations demonstrate that the released curcumin complex scavenges ROS and suppresses the activation of the ROS-NF-κB signaling pathway by inhibiting the translocation of p47-phox and p67-phox to lead to anti-inflammatory microglia polarization. Consequently, the Cur gel exhibits promising potential for promoting post-stroke rehabilitation in clinics.

The effect and optimal parameters of repetitive transcranial magnetic stimulation on lower extremity motor function in stroke patient: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in treating lower limb motor dysfunction after stroke and explore the optimal stimulation parameters.

METHODS

PubMed, Embase, Cochrane Library, and other relevant databases were systematically queried for randomised controlled trials (RCTs) investigating the efficacy of rTMS in addressing lower limb motor dysfunction post-stroke. The search encompassed records from inception to July 2022. The assessed outcomes encompassed parameters such as the Fugl-Meyer motor function score for lower limbs, balance function, and Barthel index (BI). Three independent researchers were responsible for research selection, data extraction, and quality assessment. Study screening, data extraction, and bias evaluation were performed independently by two reviewers. Data synthesis was undertaken using Review Manager 5.3, while Stata version 14.0 software was employed for generating the funnel plot.

RESULTS

A total of 13 studies and 428 patients were included. The meta-analysis indicated that rTMS had a positive effect on the BI (MD = 5.87, 95% CI [0.99, 10.76], p = 0.02, I2 = 86%, N of studies = 8, N of participants = 248). Subgroup analysis was performed on the stimulation frequency, treatment duration, and different stroke stages (stimulation frequency was low-frequency (LF)-rTMS (MD = 4.45, 95% CI [1.05, 7.85], p = 0.01, I2 = 0%, N of studies = 4, N of participants = 120); treatment time ≤ 15 d: (MD = 4.41, 95% CI [2.63, 6.18], p < 0.00001, I2 = 0%, N of studies = 4, N of participants = 124); post-stroke time ≤6 months: (MD = 4.37, 95% CI [2.42, 6.32], p < 0.0001, I2 = 0%, N of studies = 5, N of participants = 172).

CONCLUSION

LF-rTMS had a significant improvement effect on BI score, while high-frequency (HF)-rTMS and iTBS had no significant effect. And stroke time ≤6 months in patients with treatment duration ≤15 d had the best treatment effect.

Neural effects of acupuncture on stroke patients with motor dysfunction: an activation likelihood estimation meta-analysis

Background

Functional magnetic resonance imaging has been used in many studies to explore the neural mechanism of acupuncture in patients with post-stroke motor dysfunction. Inconsistent results have been found in these studies, however. This activation likelihood estimation (ALE) meta-analysis was designed to quantitatively integrate changes in brain activity and the neurological effects of acupuncture on patients with motor dysfunction after stroke.

Methods

We searched PubMed, Embase, Web of Science, the Cochrane Library, China Science and Technology Journal Database, the China Biology Medicine, the China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform for literature from the establishment of the database until March 21, 2024. Research papers were selected, data extracted, and quality assessment was done independently by two researchers. The GingerALE software was used for meta-analysis, and Jackknife sensitivity analysis was employed to assess result robustness.

Results

We ended up analyzing 14 studies that included 235 patients and 100 healthy people. ALE meta-analysis showed that Compared with healthy people, the enhanced brain region in poststroke patients with motor dysfunction was located in the left posterior lobe of the cerebellum, the left inferior frontal gyrus, and the left precuneus (p < 0.001). After acupuncture, the activated regions were mainly located in the left posterior lobe of the cerebellum, the right lentiform nucleus putamen, the right medial frontal gyrus, the right inferior frontal gyrus, the left precuneus, the right middle temporal gyrus, the left claustrum, the left cerebellar tonsil, the right superior marginal gyrus, the inactivated area is located in the right medial frontal gyrus the left precentral gyrus and the right precuneus (p < 0.001).

Conclusion

Acupuncture can reestablish motor function by causing extensive changes in the brain function of patients with stroke, which may be the neurological effect of acupuncture therapy on stroke patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024526263.

Effects of high-definition tDCS targeting individual motor hotspot with EMG-driven robotic hand training on upper extremity motor function: a pilot randomized controlled trial

BACKGROUND

Delivering HD-tDCS on individual motor hotspot with optimal electric fields could overcome challenges of stroke heterogeneity, potentially facilitating neural activation and improving motor function for stroke survivors. However, the intervention effect of this personalized HD-tDCS has not been explored on post-stroke motor recovery. In this study, we aim to evaluate whether targeting individual motor hotspot with HD-tDCS followed by EMG-driven robotic hand training could further facilitate the upper extremity motor function for chronic stroke survivors.

METHODS

In this pilot randomized controlled trial, eighteen chronic stroke survivors were randomly allocated into two groups. The HDtDCS-group (n = 8) received personalized HD-tDCS using task-based fMRI to guide the stimulation on individual motor hotspot. The Sham-group (n = 10) received only sham stimulation. Both groups underwent 20 sessions of training, each session began with 20 min of HD-tDCS and was then followed by 60 min of robotic hand training. Clinical scales (Fugl-meyer Upper Extremity scale, FMAUE; Modified Ashworth Scale, MAS), and neuroimaging modalities (fMRI and EEG-EMG) were conducted before, after intervention, and at 6-month follow-up. Two-way repeated measures analysis of variance was used to compare the training effect between HDtDCS- and Sham-group.

RESULTS

HDtDCS-group demonstrated significantly better motor improvement than the Sham-group in terms of greater changes of FMAUE scores (F = 6.5, P = 0.004) and MASf (F = 3.6, P = 0.038) immediately and 6 months after the 20-session intervention. The task-based fMRI activation significantly shifted to the ipsilesional motor area in the HDtDCS-group, and this activation pattern increasingly concentrated on the motor hotspot being stimulated 6 months after training within the HDtDCS-group, whereas the increased activation is not sustainable in the Sham-group. The neuroimaging results indicate that neural plastic changes of the HDtDCS-group were guided specifically and sustained as an add-on effect of the stimulation.

CONCLUSIONS

Stimulating the individual motor hotspot before robotic hand training could further enhance brain activation in motor-related regions that promote better motor recovery for chronic stroke.

TRIAL REGISTRATION

This study was retrospectively registered in ClinicalTrials.gov (ID NCT05638464).

A 3D-Printed helmet for precise and repeatable neuromodulation targeting in awake non-human primates

The application of non-invasive brain stimulation (NIBS) in non-human primates (NHPs) is critical for advancing understanding of brain networks and developing treatments for neurological diseases. Improving the precision of targeting can significantly enhance the efficacy of these interventions. Here, we introduce a 3D-printed helmet designed to achieve repeatable and precise neuromodulation targeting in awake rhesus monkeys, eliminating the need of head fixation. Imaging studies confirmed that the helmet consistently targets the primary motor cortex (M1) with a margin of error less than 1 mm. Evaluations of stimulation efficacy revealed high resolution and stability. Additionally, physiological evaluations under propofol anesthesia showed that the helmet effectively facilitated the generation of recruitment curves for motor area, confirming successful neuromodulation. Collectively, our findings present a straightforward and effective method for achieving consistent and precise NIBS targeting in awake NHPs, potentially advancing both basic neuroscience research and the development of clinical neuromodulation therapies.

MiR-100-5p-rich small extracellular vesicles from activated neuron to aggravate microglial activation and neuronal activity after stroke

Ischemic stroke is a common cause of mortality and severe disability in human and currently lacks effective treatment. Neuronal activation and neuroinflammation are the major two causes of neuronal damage. However, little is known about the connection of these two phenomena. This study uses middle cerebral artery occlusion mouse model and chemogenetic techniques to study the underlying mechanisms of neuronal excitotoxicity and severe neuroinflammation after ischemic stroke. Chemogenetic inhibition of neuronal activity in ipsilesional M1 alleviates infarct area and neuroinflammation, and improves motor recovery in ischemia mice. This study identifies that ischemic challenge triggers neuron to produce unique small extracellular vesicles (EVs) to aberrantly activate adjacent neurons which enlarge the neuron damage range. Importantly, these EVs also drive microglia activation to exacerbate neuroinflammation. Mechanistically, EVs from ischemia-evoked neuronal activity induce neuronal apoptosis and innate immune responses by transferring higher miR-100-5p to adjacent neuron and microglia. MiR-100-5p can bind to and activate TLR7 through U18U19G20-motif, thereby activating NF-κB pathway. Furthermore, knock-down of miR-100-5p expression improves poststroke outcomes in mice. Taken together, this study suggests that the combination of inhibiting aberrant neuronal activity and the secretion of specific EVs-miRNAs may serve as novel methods for stroke treatment.

Corticospinal premotor fibers facilitate complex motor control after stroke

OBJECTIVE

The corticospinal tract (CST) is considered the most important motor output pathway comprising fibers from the primary motor cortex (M1) and various premotor areas. Damage to its descending fibers after stroke commonly leads to motor impairment. While premotor areas are thought to critically support motor recovery after stroke, the functional role of their corticospinal output for different aspects of post-stroke motor control remains poorly understood.

METHODS

We assessed the differential role of CST fibers originating from premotor areas and M1 in the control of basal (single-joint muscle synergies and strength) and complex motor control (involving inter-joint coordination and visuomotor integration) using a novel diffusion imaging approach in chronic stroke patients.

RESULTS

While M1 sub-tract anisotropy was positively correlated with basal and complex motor skills, anisotropy of PMd, PMv, and SMA sub-tracts was exclusively associated with complex motor tasks. Interestingly, patients featuring persistent motor deficits showed an additional positive association between premotor sub-tract integrity and basal motor control.

INTERPRETATION

While descending M1 output seems to be a prerequisite for any form of upper limb movements, complex motor skills critically depend on output from premotor areas after stroke. The additional involvement of premotor tracts in basal motor control in patients with persistent deficits emphasizes their compensatory capacity in post-stroke motor control. In summary, our findings highlight the pivotal role of descending corticospinal output from premotor areas for motor control after stroke, which thus serve as prime candidates for future interventions to amplify motor recovery.

The cerebellum and the Mirror Neuron System: A matter of inhibition? From neurophysiological evidence to neuromodulatory implications. A narrative review

Mirror neurons show activity during both the execution (AE) and observation of actions (AO). The Mirror Neuron System (MNS) could be involved during motor imagery (MI) as well. Extensive research suggests that the cerebellum is interconnected with the MNS and may be critically involved in its activities. We gathered evidence on the cerebellum's role in MNS functions, both theoretically and experimentally. Evidence shows that the cerebellum plays a major role during AO and MI and that its lesions impair MNS functions likely because, by modulating the activity of cortical inhibitory interneurons with mirror properties, the cerebellum may contribute to visuomotor matching, which is fundamental for shaping mirror properties. Indeed, the cerebellum may strengthen sensory-motor patterns that minimise the discrepancy between predicted and actual outcome, both during AE and AO. Furthermore, through its connections with the hippocampus, the cerebellum might be involved in internal simulations of motor programs during MI. Finally, as cerebellar neuromodulation might improve its impact on MNS activity, we explored its potential neurophysiological and neurorehabilitation implications.

The effect of transcranial direct current stimulation on balance, gait function and quality of life in patients with stroke

Transcranial direct current stimulation (tDCS) has been used in various neurological diseases due to its positive effects on cortical excitability. The aim of our study is to examine the effects of tDCS in stroke and 28 patients with stroke were randomly divided into two groups as intervention and control groups. Balance was evaluated with the Timed Up and Go Test and Berg Balance Scale. Walking functions were evaluated using the 10-meter Walk Test and the 6 Minutes Walk Test, lower extremity function was evaluated by Fugl Meyer Lower Extremity Scale, quality of life by Stroke-Specific Quality of Life Scale (SS-QOL). A task-oriented physiotherapy and rehabilitation program was applied to both groups. In addition to the task-oriented program, anodal tDCS was applied in the intervention group and carried out with a current of 2 mA, 5 days a week, 20 min, for a total of 4 weeks. In the control group, after the flow was opened for 30 s and the patient felt a tingling sensation, it was turned off without the patient noticing. As a result, significant improvement was obtained in all parameters in both groups (p < 0.05). At the difference values of both groups, only SS-QOL mobility subgroup was significant and other parameters were not significant. Considering all these results, it can be seen that tDAS applied in addition to the task-oriented training program in individuals with stroke makes a positive contribution to the patients' balance, walking function and quality of life. We think that tDAS may be a feasible and safe additional approach in this patient group.

Transcranial electrical stimulation for procedural learning and rehabilitation

Procedural learning is the acquisition of motor and non-motor skills through a gradual process that increases with practice. Impairments in procedural learning have been consistently demonstrated in neurodevelopmental, neurodegenerative, and neuropsychiatric disorders. Considering that noninvasive brain stimulation modulates brain activity and boosts neuroplastic mechanisms, we reviewed the effects of coupling transcranial direct current stimulation (tDCS) with training methods for motor and non-motor procedural learning to explore tDCS potential use as a tool for enhancing implicit learning in healthy and clinical populations. The review covers tDCS effects over i. motor procedural learning, from basic to complex activities; ii. non-motor procedural learning; iii. procedural rehabilitation in several clinical populations. We conclude that targeting the primary motor cortex and prefrontal areas seems the most promising for motor and non-motor procedural learning, respectively. For procedural rehabilitation, the use of tDCS is yet at an early stage but some effectiveness has been reported for implicit motor and memory learning. Still, systematic comparisons of stimulation parameters and target areas are recommended for maximising the effectiveness of tDCS and its robustness for procedural rehabilitation.

Bilateral median nerve stimulation and High-Frequency Oscillations unveil interhemispheric inhibition of primary sensory cortex

OBJECTIVE

This study aimed at investigating the effect of median nerve stimulation on ipsilateral cortical potentials evoked by contralateral median nerve electrical stimulation.

METHODS

We recorded somatosensory-evoked potentials (SEPs) from the left parietal cortex in 15 right-handed, healthy subjects. We administered bilateral median nerve stimulation, with the ipsilateral stimulation preceding the stimulation on the contralateral by intervals of 5, 10, 20, or 40 ms. We adjusted these intervals based on each individual's N20 latency. As a measure of S1 excitability, the amplitude of the N20 and the area of the High Frequency Oscillation (HFO) burst were analyzed for each condition.

RESULTS

The results revealed significant inhibition of N20 amplitude by ipsilateral median nerve stimulation at interstimulus intervals (ISIs) between 5 and 40 ms. Late HFO burst was suppressed at short ISIs of 5 and 10 ms, pointing to a transcallosal inhibitory effect on S1 intracortical circuits.

CONCLUSIONS

Findings suggest interhemispheric interaction between the primary somatosensory areas, supporting the existence of transcallosal transfer of tactile information.

SIGNIFICANCE

This study provides valuable insights into the interhemispheric connections between primary sensory areas and underscore the potential role of interhemispheric interactions in somatosensory processing.

Global research trends in transcranial magnetic stimulation for stroke (1994-2023): promising, yet requiring further practice

Background

Scholars have been committed to investigating stroke rehabilitation strategies over many years. Since its invention, transcranial magnetic stimulation (TMS) has been increasingly employed in contemporary stroke rehabilitation research. Evidence has shown the significant potential of TMS in stroke research and treatment.

Objective

This article reviews the research conducted on the use of TMS in stroke from 1994 to 2023. This study applied bibliometric analysis to delineate the current research landscape and to anticipate future research hotspots.

Method

The study utilized the Web of Science Core Collection to retrieve and acquire literature data. Various software tools, including VOSviewer (version 1.6.19), CiteSpace (version 6.3.R1), Scimago Graphica (version 1.0.36), and WPS (version 11572), were used for data analysis and visualization. The review included analyses of countries, institutions, authors, journals, articles, and keywords.

Results

A total of 3,425 articles were collected. The top three countries in terms of publication output were the United States (953 articles), China (546 articles), and Germany (424 articles). The United States also had the highest citation counts (56,764 citations), followed by Germany (35,211 citations) and the United Kingdom (32,383 citations). The top three institutions based on the number of publications were Harvard University with 138 articles, the University of Auckland with 81 articles, and University College London with 80 articles. The most prolific authors were Abo, Masahiro with 54 articles, Fregni, Felipe with 53 articles, and Pascual-Leone, Alvaro with 50 articles. The top three journals in terms of article count were Neurorehabilitation and Neural Repair with 139 articles, Clinical Neurophysiology with 128 articles, and Frontiers in Neurology with 110 articles. The most frequently occurring keywords were stroke (1,275 occurrences), transcranial magnetic stimulation (1,119 occurrences), and rehabilitation (420 occurrences).

Conclusion

The application of TMS in stroke research is rapidly gaining momentum, with the USA leading in publications. Prominent institutions, such as Harvard University and University College London, show potential for collaborative research. The key areas of focus include post-stroke cognitive impairment, aphasia, and dysphagia, which are expected to remain significant hotspots in future research. Future research should involve large-scale, randomized, and controlled trials in these fields. Additionally, identifying more effective combined therapies with rTMS should be a priority.

Brain state-dependent repetitive transcranial magnetic stimulation for motor stroke rehabilitation: a proof of concept randomized controlled trial

Background

In healthy subjects, repetitive transcranial magnetic stimulation (rTMS) targeting the primary motor cortex (M1) demonstrated plasticity effects contingent on electroencephalography (EEG)-derived excitability states, defined by the phase of the ongoing sensorimotor μ-oscillation. The therapeutic potential of brain state-dependent rTMS in the rehabilitation of upper limb motor impairment post-stroke remains unexplored.

Objective

Proof-of-concept trial to assess the efficacy of rTMS, synchronized to the sensorimotor μ-oscillation, in improving motor impairment and reducing upper-limb spasticity in stroke patients.

Methods

We conducted a parallel group, randomized double-blind controlled trial in 30 chronic stroke patients (clinical trial registration number: NCT05005780). The experimental intervention group received EEG-triggered rTMS of the ipsilesional M1 [1,200 pulses; 0.33 Hz; 100% of the resting motor threshold (RMT)], while the control group received low-frequency rTMS of the contralesional motor cortex (1,200 pulses; 1 Hz, 115% RMT), i.e., an established treatment protocol. Both groups received 12 rTMS sessions (20 min, 3× per week, 4 weeks) followed by 50 min of physiotherapy. The primary outcome measure was the change in upper-extremity Fugl-Meyer assessment (FMA-UE) scores between baseline, immediately post-treatment and 3 months' follow-up.

Results

Both groups showed significant improvement in the primary outcome measure (FMA-UE) and the secondary outcome measures. This included the reduction in spasticity, measured objectively using the hand-held dynamometer, and enhanced motor function as measured by the Wolf Motor Function Test (WMFT). There were no significant differences between the groups in any of the outcome measures.

Conclusion

The application of brain state-dependent rTMS for rehabilitation in chronic stroke patients is feasible. This pilot study demonstrated that the brain oscillation-synchronized rTMS protocol produced beneficial effects on motor impairment, motor function and spasticity that were comparable to those observed with an established therapeutic rTMS protocol.

Clinical Trial Registration

ClinicalTrials.gov, identifier [NCT05005780].

How does combining physical therapy with transcranial direct stimulation improve upper-limb motor functions in patients with stroke? A theory perspective

More than half of stroke survivors suffer from upper-limb dysfunction that persists years after stroke, negatively impacting patients' independence and, therefore, affecting their quality of life. Intense motor rehabilitation is required after a stroke to facilitate motor recovery. More importantly, finding new ways to maximize patients' motor recovery is a core goal of stroke rehabilitation. Thus, researchers have explored the potential benefits of combining the effects of non-invasive brain stimulation with physical therapy rehabilitation. Specifically, combining transcranial direct stimulation (tDCS) with neurorehabilitation interventions can boost the brain's responses to interventions and maximize the effects of rehabilitation to improve upper-limb recovery post-stroke. However, it is still unclear which modes of tDCS are optimal for upper-limb motor recovery in patients with stroke when combined with physical therapy interventions. Here, the authors review the existing literature suggesting combining physical therapy rehabilitation with tDCS can maximize patients' motor recovery using the Interhemispheric Competition Model in Stroke. The authors focus on two main rehabilitation paradigms, which are constraint-induced movement therapy (CIMT) and Mirror therapy with and without tDCS. The authors also discuss potential studies to elucidate further the benefit of using tDCS adjunct with these upper-limb rehabilitation paradigms and its effectiveness in patients with stroke, with the ultimate goal of maximizing patients' motor recovery.

Comparative efficacy of different noninvasive brain stimulation protocols on upper-extremity motor function and activities of daily living after stroke: a systematic review and network meta-analysis

The objectives of the study were to systematically evaluate the rehabilitation effect of noninvasive brain stimulation (NIBS) on upper extremity motor function and activities of daily living in stroke patients and to prioritize various stimulation protocols for reliable evidence-based medical recommendations in patients with upper extremity motor dysfunction after stroke. Web of Science, PubMed, Embase, Cochrane Library, CNKI, Wanfang, VIP, and CBM were searched to collect all randomized controlled trials (RCTs) of NIBS to improve upper extremity motor function in stroke patients. The retrieval time was from the establishment of all databases to May 2023. According to the Cochrane system evaluation manual, the quality of the included studies was evaluated, and the data were extracted. Statistical analysis was carried out by using RevMan 5.3, R 4.3.0, and Stata 17.0 software. Finally, 94 RCTs were included, with a total of 5546 patients. Meta-analysis showed that NIBS improved the Fugl-Meyer assessment (FMA) score (mean difference (MD) = 6.51, 95% CI 6.20 ~ 6.82, P < 0.05), MBI score (MD = 7.69, 95% CI 6.57 ~ 8.81, P < 0.05), ARAT score (MD = 5.06, 95% CI 3.85 ~ 6.27, P < 0.05), and motor evoked potential (MEP) amplitude. The modified Ashworth scale score (MD =  - 0.37, 95% CI - 0.60 to - 0.14, P < 0.05), National Institutes of Health Stroke Scale score (MD =  - 2.17, 95% CI - 3.32 to - 1.11, P < 0.05), incubation period of MEP (MD =  - 0.72, 95% CI - 1.06 to - 0.38, P < 0.05), and central motor conduction time (MD =  - 0.90, 95% CI - 1.29 to - 0.50, P < 0.05) were decreased in stroke patients. Network meta-analysis showed that the order of interventions in improving FMA scores from high to low was anodal-transcranial direct current stimulation (tDCS) (surface under the cumulative ranking curve (SUCRA) = 83.7%) > cathodal-tDCS (SUCRA = 80.2%) > high-frequency (HF)-repetitive transcranial magnetic stimulation (rTMS) (SUCRA = 68.5%) > low-frequency (LF)-rTMS (SUCRA = 66.5%) > continuous theta burst stimulation (cTBS) (SUCRA = 54.2%) > bilateral-tDCS (SUCRA = 45.2%) > intermittent theta burst stimulation (iTBS) (SUCRA = 34.1%) > sham-NIBS (SUCRA = 16.0%) > CR (SUCRA = 1.6%). In terms of improving MBI scores, the order from high to low was anodal-tDCS (SUCRA = 88.7%) > cathodal-tDCS (SUCRA = 85.4%) > HF-rTMS (SUCRA = 63.4%) > bilateral-tDCS (SUCRA = 56.0%) > LF-rTMS (SUCRA = 54.2%) > iTBS (SUCRA = 32.4%) > sham-NIBS (SUCRA = 13.8%) > CR (SUCRA = 6.1%). NIBS can effectively improve upper extremity motor function and activities of daily living after stroke. Among the various NIBS protocols, anodal-tDCS demonstrated the most significant intervention effect, followed by cathodal-tDCS and HF-rTMS.

Cortical plasticity in AQP4-positive NMOSD: a transcranial magnetic stimulation study

Aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) is an autoimmune disease characterized by suboptimal recovery from attacks and long-term disability. Experimental data suggest that AQP4 antibodies can disrupt neuroplasticity, a fundamental driver of brain recovery. A well-established method to assess brain LTP is through intermittent theta-burst stimulation (iTBS). This study aimed to explore neuroplasticity in AQP4-NMOSD patients by examining long-term potentiation (LTP) through iTBS. We conducted a proof-of-principle study including 8 patients with AQP4-NMOSD, 8 patients with multiple sclerosis (MS), and 8 healthy controls (HC) in which iTBS was administered to induce LTP-like effects. iTBS-induced LTP exhibited significant differences among the 3 groups (p: 0.006). Notably, AQP4-NMOSD patients demonstrated impaired plasticity compared to both HC (p = 0.01) and pwMS (p = 0.02). This pilot study provides the first in vivo evidence supporting impaired neuroplasticity in AQP4-NMOSD patients. Impaired cortical plasticity may hinder recovery following attacks suggesting a need for targeted rehabilitation strategies.

Facilitating Corticomotor Excitability of the Contralesional Hemisphere Using Non-Invasive Brain Stimulation to Improve Upper Limb Motor Recovery from Stroke-A Scoping Review

Upper limb weakness following stroke poses a significant global psychosocial and economic burden. Non-invasive brain stimulation (NIBS) is a potential adjunctive treatment in rehabilitation. However, traditional approaches to rebalance interhemispheric inhibition may not be effective for all patients. The supportive role of the contralesional hemisphere in recovery of upper limb motor function has been supported by animal and clinical studies, particularly for those with severe strokes. This review aims to provide an overview of the facilitation role of the contralesional hemisphere for post-stroke motor recovery. While more studies are required to predict responses and inform the choice of NIBS approach, contralesional facilitation may offer new hope for patients in whom traditional rehabilitation and NIBS approaches have failed.

Effects of repetitive transcranial magnetic stimulation on lower extremity motor function and optimal parameters in stroke patients with different stages of stroke: a systematic evaluation and meta-analysis

Background

Repetitive transcranial magnetic stimulation (rTMS), as an emerging non-invasive neuromodulation technique, is now widely employed in rehabilitation therapy. The purpose of this paper is to comprehensively summarize existing evidence regarding rTMS intervention for lower limb motor function in patients at different stages of stroke.

Methods

A systematic search was conducted to identify randomized controlled trials (RCTs) assessing the efficacy of rTMS for treating lower limb motor dysfunction after stroke. Multiple databases, including China National Knowledge Infrastructure (CNKI), Wanfang Data Knowledge Service Platform, VIP Database, PubMed, Embase, Web of Science, and Cochrane Library, were searched. The search period extended from the inception of the libraries to June 2024. Literature information was extracted, and methodological quality was evaluated using the risk of bias assessment tool in the Cochrane Handbook. Meta-analysis was performed using Stata 17.0 software.

Results

Overall, 49 appropriate studies (including 3,558 stroke subjects) were found. Meta-analysis results demonstrated that rTMS effectively improved lower limb motor function across all stages of stroke. The intervention was particularly more effective in patients in the subacute stage than in the acute or chronic stages. Subgroup analysis revealed that, for acute-stage patients, low-frequency stimulation targeting the M1 or DLPFC brain regions on the unaffected side with 20-40 sessions significantly improved FMA-LE scores. In subacute-phase patients, low-frequency stimulation targeting the M1 brain regions on the unaffected side with 18 sessions significantly improved FMA-LE scores. The results demonstrated that HF-rTMS was more effective than LF-rTMS in improving walking speed, with the greatest efficacy observed at 20 sessions. While for enhancing gait balance in stroke patients, LF-rTMS with the best therapeutic effect was observed at a frequency of 20-40 treatments.

Conclusion

This study demonstrates the efficacy of rTMS in improving lower limb motor function, balance, and walking speed in stroke patients at various stages. The findings provide a valuable reference for the development of optimized rTMS treatment plans in clinical practice.Systematic review registration: PROSPERO: CRD42023466094.

Detection of early neurological deterioration using a quantitative electroencephalography system in patients with large vessel occlusion stroke after endovascular treatment

BACKGROUND

Early neurological deterioration (END) is a serious complication in patients with large vessel occlusion (LVO) stroke. However, modalities to monitor neurological function after endovascular treatment (EVT) are lacking. This study aimed to evaluate the diagnostic accuracy of a quantitative electroencephalography (qEEG) system for detecting END.

METHODS

In this prospective, nested case-control study, we included 47 patients with anterior circulation LVO stroke and 34 healthy adults from different clinical centers in Tianjin, China, from May 2023 to January 2024. Patients with stroke underwent EEG at admission and after EVT. The diagnostic accuracy of qEEG features for END was evaluated by receiver operating characteristic curve analysis, and the feasibility was evaluated by the percentage of artifact-free data and device-related adverse events.

RESULTS

14 patients with stroke had END (29.8%, 95% CI 16.2% to 43.4%), with most developed within 12 hours of recanalization (n=11). qEEG features showed significant correlations with National Institutes of Health Stroke Scale score and infarct volume. After matching, 13 patients with END and 26 controls were included in the diagnostic analysis. Relative alpha power demonstrated the highest diagnostic accuracy for the affected and unaffected hemispheres. The optimal electrode positions were FC3/4 in the unaffected hemisphere, and F7/8 and C3/4 in the affected hemisphere. No device-related adverse events were reported.

CONCLUSION

The qEEG system exhibits a high diagnostic accuracy for END and may be a promising tool for monitoring neurological function. The identification of optimal electrode positions may enhance device convenience.

CLINICAL TRIAL REGISTRATION

ChiCTR 2300070829.

Theoretical proposal for restoration of hand motor function based on plasticity of motor-cortical interhemispheric interaction and its developmental rule

After stroke, the poorer recovery of motor function of upper extremities compared to other body parts is a longstanding problem. Based on our recent functional MRI evidence on healthy volunteers, this perspective paper proposes systematic hand motor rehabilitation utilizing the plasticity of interhemispheric interaction between motor cortices and following its developmental rule. We first discuss the effectiveness of proprioceptive intervention on the paralyzed (immobile) hand synchronized with voluntary movement of the intact hand to induce muscle activity in the paretic hand. In healthy participants, we show that this bilateral proprioceptive-motor coupling intervention activates the bilateral motor cortices (= bilaterally active mode), facilitates interhemispheric motor-cortical functional connectivity, and augments muscle activity of the passively-moved hand. Next, we propose training both hands to perform different movements, which would be effective for stroke patients who becomes able to manage to move the paretic hand. This bilaterally different movement training may guide the motor cortices into left-right independent mode to improve interhemispheric inhibition and hand dexterity, because we have shown in healthy older adults that this training reactivates motor-cortical interhemispheric inhibition (= left-right independent mode) declined with age, and can improve hand dexterity. Transition of both motor cortices from the bilaterally active mode to the left-right independent mode is a developmental rule of hand motor function and a common feature of motor function recovery after stroke. Hence, incorporating the brain's inherent capacity for spontaneous recovery and adhering to developmental principles may be crucial considerations in designing effective rehabilitation strategies.