Effects of high-frequency repetitive transcranial magnetic stimulation over the contralesional motor cortex on motor recovery in severe hemiplegic stroke: A randomized clinical trial

Cerebellar Intermittent Theta-Burst Stimulation Reduces Upper Limb Spasticity After Subacute Stroke: A Randomized Controlled Trial

Objective: This study aims to explore the efficacy of cerebellar intermittent theta-burst stimulation (iTBS) on upper limb spasticity in subacute stroke patients.

Methods: A total of 32 patients with upper limb spasticity were enrolled and randomly assigned to treatment with cerebellar iTBS or sham stimulation before conventional physical therapy daily for 2 weeks. The primary outcomes included the modified Ashworth scale (MAS), the modified Tardieu scale (MTS), and the shear wave velocity (SWV). The secondary outcomes were the H-maximum wave/M-maximum wave amplitude ratio (H_max/M_max ratio), motor-evoked potential (MEP) latency and amplitude, central motor conduction time (CMCT), and the Barthel Index (BI). All outcomes were evaluated at baseline and after 10 sessions of intervention.

Results: After the intervention, both groups showed significant improvements in the MAS, MTS, SWV, and BI. In addition, patients treated with cerebellar iTBS had a significant increase in MEP amplitude, and patients treated with sham stimulation had a significant decrease in H_max/M_max ratio. Compared with the sham stimulation group, the MAS, MTS, and SWV decreased more in the cerebellar iTBS group.

Conclusion: Cerebellar iTBS is a promising adjuvant tool to reinforce the therapeutic effect of conventional physical therapy in upper limb spasticity management after subacute stroke (Chinese Clinical Trial Registry: ChiCTR1900026516).

Effects of High-Frequency (HF) Repetitive Transcranial Magnetic Stimulation (rTMS) on Upper Extremity Motor Function in Stroke Patients: A Systematic Review

Background and Objectives: Repetitive transcranial magnetic stimulation (rTMS) is being widely used for treating upper extremity paresis after stroke, however, evidence of applying high-frequency rTMS (HF-rTMS) on the ipsilesional hemisphere for upper extremity motor recovery remains limited. This systematic review aimed to investigate the effect of high-frequency repetitive transcranial magnetic stimulation for upper extremity motor function recovery after a first-time ischaemic stroke. Materials and Methods: This systematic review was prepared according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A comprehensive literature search was performed to identify all studies published before 12 February 2021. The search was performed on the following databases: PubMed, Ovid, The Cochrane Library. Results: A total of 6440 studies were found in the databases and four trials were included in the review. Three of the studies were randomized control trials (RCT), and one was a pseudo-RCT. Three of the studies showed good methodological quality and one study was rated as excellent. Fugl-Meyer Assessment (FMA) was performed in three out of four studies and the score significantly increased in the HF-rTMS treatment group compared with sham stimulation in all trials. Other measures used in the studies were handgrip strength, shoulder abduction, Motricity Index, Wolf Motor Function Test (WMFT), and Box and Block, although these tests did not show unanimous results. Overall, all four studies conveyed significantly better results in at least one test that was performed for hand motor function evaluation in a 10 Hz stimulation group while none of the tests showed any advantage for sham stimulation groups. Two studies reported headache as an adverse event (six patients in total). Conclusion: The overall results showed that HF-rTMS may increase impaired upper extremity motor function better than sham stimulation in stroke patients.

Perinatal stroke: mapping and modulating developmental plasticity

Most cases of hemiparetic cerebral palsy are caused by perinatal stroke, resulting in lifelong disability for millions of people. However, our understanding of how the motor system develops following such early unilateral brain injury is increasing. Tools such as neuroimaging and brain stimulation are generating informed maps of the unique motor networks that emerge following perinatal stroke. As a focal injury of defined timing in an otherwise healthy brain, perinatal stroke represents an ideal human model of developmental plasticity. Here, we provide an introduction to perinatal stroke epidemiology and outcomes, before reviewing models of developmental plasticity after perinatal stroke. We then examine existing therapeutic approaches, including constraint, bimanual and other occupational therapies, and their potential synergy with non-invasive neurostimulation. We end by discussing the promise of exciting new therapies, including novel neurostimulation, brain-computer interfaces and robotics, all focused on improving outcomes after perinatal stroke.

High-Frequency rTMS Improves Cognitive Function by Regulating Synaptic Plasticity in Cerebral Ischemic Rats

Poststroke cognitive impairment (PSCI) is one of the most severe sequelae of stroke and lacks effective treatment. Previous studies have shown that high-frequency repetitive transcranial magnetic stimulation (rTMS) may be a promising PSCI therapeutic approach, but the underlying mechanism is unclear. To uncover the effect of rTMS on PSCI, a transient middle cerebral artery occlusion (tMCAO) model was established. Modified Neurological Severity Score (mNSS) test and Morris Water Maze (MWM) test were performed to assess the neurological and cognitive function of rats. Furthermore, to explore the underlying mechanism, differentially expressed genes (DEGs) in the hippocampus of rats in the rTMS group and tMCAO group were compared using RNA sequencing. Then, bioinformatics analysis, including gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein-protein interaction (PPI) network analysis, was conducted to elaborate these DEGs. Our results indicated that high-frequency rTMS could significantly improve neurological and cognitive function, according to mNSS and MWM tests. We found 85 DEGs, including 71 upregulated genes and 14 downregulated genes, between the rTMS group and tMCAO group. The major functional category was related to chemical synaptic transmission modulation and several DEGs were significantly upregulated in processes related to synaptic plasticity, such as glutamatergic synapses. Calb2, Zic1, Kcnk9, and Grin3a were notable in PPI analysis. These results demonstrate that rTMS has a beneficial effect on PSCI, and its mechanism may be related to the regulation of synaptic plasticity and functional genes such as Calb2, Zic1, Kcnk9, and Grin3a in the hippocampus.

Prediction of Motor Recovery in the Upper Extremity for Repetitive Transcranial Magnetic Stimulation and Occupational Therapy Goal Setting in Patients With Chronic Stroke: A Retrospective Analysis of Prospectively Collected Data

Recovery from motor paralysis is facilitated by affected patients' recognition of the need for and practice of their own exercise goals. Neurorehabilitation has been proposed and used for the treatment of motor paralysis in stroke, and its effect has been verified. If an expected score for the neurorehabilitation effect can be calculated using the Fugl-Meyer Motor Assessment (FMA), a global assessment index, before neurorehabilitation, such a score will be useful for optimizing the treatment application criteria and for setting a goal to enhance the treatment effect. Therefore, this study verified whether the responsiveness to a treatment method, the NovEl intervention using repetitive transcranial magnetic stimulation and occupational therapy (NEURO), in patients with post-stroke upper extremity (UE) motor paralysis could be predicted by the pretreatment FMA score. No control group was established in this study for NEURO treatment. To analyze the recovery of the motor function in the UE, delta-FMA was calculated from the pre- and post-FMA scores obtained during NEURO treatment. The probability of three levels of treatment responsiveness was evaluated in association with delta-FMA score (<5, 5 ≤ delta-FMA <10, and ≥10 as non-responders; responders; and hyper-responders, respectively) according to the reported minimal clinically important difference (MCID). The association of the initial FMA scores with post-FMA scores, from the status of the treatment responsiveness, was determined by multinomial logistic regression analysis. Finally, 1,254 patients with stroke, stratified by FMA scores were analyzed. About 45% of the patients who had FMA scores ranging from 30 to 40 before treatment showed improvement over the MCID by NEURO treatment (odds ratio = 0.93, 95% CI = 0.92–0.95). Furthermore, more than 25% of the patients with more severe initial values, ranging from 26 to 30, improved beyond the MCID calculated in the acute phase (odds ratio = 0.87, 95% CI = 0.85–0.89). These results suggest that the evaluated motor function score of the UE before NEURO treatment can be used to estimate the possibility of a patient recovering beyond MCID in the chronic phase. This study provided clinical data to estimate the effect of NEURO treatment by the pretreatment FMA-UE score.

Promotion of Poststroke Motor-Function Recovery with Repetitive Transcranial Magnetic Stimulation by Regulating the Interhemispheric Imbalance

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain-stimulation technique that transiently modulates cerebral cortex excitability, achieving overall positive results in poststroke motor-function recovery. Excessive inhibition of the ipsilesional-affected hemisphere by the contralesional-unaffected hemisphere has seriously hindered poststroke motor-function recovery. Hence, intracortical disinhibition can be used as an approach to managing poststroke brain injury. This technique promotes neural plasticity for faster motor-function recovery. rTMS relieves unilateral inhibition of the brain function by regulatinga interhemispheric-imbalanced inhibition. This paper summarized 12 studies from 2016 to date, focusing on rTMS on motor function after acute and chronic stroke by regulating the interhemispheric imbalance of inhibitory inputs. Although rTMS studies have shown promising outcomes on recovery of motor functions in stroke patients, different intervention methods may lead to discrepancies in results. A uniform optimal stimulus model cannot routinely be used, mainly due to the stimulus schemes, stroke types and outcome-measuring differences among studies. Thus, the effect of rTMS on poststroke motor-function recovery should be investigated further to standardize the rTMS program for optimal poststroke motor-function recovery. More randomized, placebo-controlled clinical trials with standardized rTMS protocols are needed to ensure the effectiveness of the treatment.

Observation for the effect of rTMS combined with magnetic stimulation at Neiguan (PC6) and Sanyinjiao (SP6) points on limb function after stroke: A study protocol

BACKGROUND

Stroke is the primary cause of adult disability in China, which causes serious personal, family, and social burden. "Central peripheral central" closed-loop rehabilitation theory is proved to be an effective neural rehabilitation model. Based on this theory, repetitive transcranial magnetic stimulation (rTMS) combined with magnetic stimulation of Neiguan (PC6) and Sanyinjiao (SP6) may be an effective treatment for limb dysfunction after stroke. However, the efficacy and mechanism of repetitive magnetic stimulation of M1 region combined with magnetic stimulation of Neiguan and Sanyinjiao points on limb dysfunction after stroke has not been confirmed.

METHODS/DESIGN

This study is a prospective, randomized, controlled, open trial. We randomly divided 42 subjects, aged 35 to 80 years, diagnosed with ischemic stroke within 1 month, into 2 groups with a ratio of 1:1. On the basis of this medical treatment, patients in the experimental group received 1 Hz rTMS in M1 area on the contralateral side, and 3 Hz rTMS treatment at Neiguan point and Sanyinjiao point on the affected side. The control group was treated with acupuncture (body acupuncture). All patients were treated once a day and followed up for 10 days. The National Institute of Health Stroke Scale score, simplified fulg Meyer, modified Barthel index, and cortical excitability were evaluated on the day of enrollment and the 10th day of treatment respectively. The modified Barthe index was followed up on the 30th day of treatment, and the adverse reactions were recorded at any time. The mechanism of rTMS will be revealed by Barthe index before treatment, on the 10th day of treatment and on the 30th day of follow-up. The results were analyzed by spss19.0 software, and the quantitative indexes were analyzed by t test and rank sum test. χ test was used for non-grade counting, and rank sum test was used for grade counting. All statistical tests were performed with bilateral test. If P value is less than or equal to .05, the difference will be considered statistically significant.

CONCLUSION

The purpose of this study was to determine the effect of repetitive magnetic stimulation of M1 region combined with magnetic stimulation of Neiguan and Sanyinjiao points on limb function after stroke. Through this study, we expect to explore a new scheme for the treatment of poststroke dyskinesia, and prove that compared with rTMS and acupuncture alone, the closed-loop rehabilitation theory based on "center peripheral center" can be more efficient and safe in the treatment of poststroke limb dysfunction.

TRIAL REGISTRATION

The trial was registered in China clinical trial registry (http://www.chictr.org.cn/index.aspx), ID: ChiCTR1900026890 (October 25, 2019).