Repetitive transcranial magnetic stimulation of lower limb motor function in patients with stroke: a systematic review and meta-analysis of randomized controlled trials

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.

Effect of short-term 10 Hz repeated transcranial magnetic stimulation on postural control ability in patients with mild hemiparesis in acute ischemic stroke: a single-blinded randomized controlled trial

Background

Previous studies have demonstrated that repetitive transcranial magnetic stimulation (rTMS) can improve postural control in subacute and chronic ischemic stroke, but further research is needed to investigate the effect of rTMS on acute ischemic stroke.

Objective

We compared the therapeutic effects of rTMS plus conventional rehabilitation and conventional rehabilitation on postural control in patients with mild hemiparesis in acute ischemic stroke.

Methods

Eighty-six patients with acute ischemic stroke were randomly assigned to either the experimental group or the control group within 1-7 days of onset. Patients in both groups received conventional rehabilitation for 2 weeks. Patients in the experimental group received rTMS treatments lasting for 2 weeks. Before and after the 2-week treatment, patients were assessed based on the Timed up and Go (TUG) test, Dual-Task Walking (DTW) test, Functional Ambulation Category (FAC), Tinetti Performance Oriented Mobility Assessment (POMA), gait kinematic parameters, Barthel Index (BI), Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and National Institutes of Health Stroke Scale (NIHSS). Additionally, TUG and single-task gait velocity were assessed at 2 months after the start of treatment, and independent walking recovery was also followed up.

Results

After 2 weeks of treatment, compared to conventional rehabilitation, participants who underwent rTMS treatment plus conventional rehabilitation exhibited notable enhancements in TUG, FAC, POMA, and some gait parameters [single-task gait velocity, gait stride length, gait cadence, gait cycle]. Changes in cognitive function partially mediated the improvement in single-task gait velocity and gait stride length by rTMS plus conventional rehabilitation. Generalized Estimating Equation (GEE) analysis showed that the trend of improvement in single-task gait velocity over time was more pronounced in the experimental group than in the control group. The results of the Kaplan-Meier curve indicated a median gait recovery time of 90 days for patients in the experimental group and 100 days for the control group. Multifactorial Cox regression analyses showed that rTMS plus conventional rehabilitation promoted faster recovery of independent walking compared with conventional rehabilitation.

Conclusion

rTMS plus conventional rehabilitation outperformed conventional rehabilitation in improving postural control in patients with acute ischemic stroke. Improvements in cognitive function may serve as a mediating factor in the favorable treatment outcome of rTMS plus conventional rehabilitation for improving postural control.

Clinical trial registration

https://www.chictr.org.cn, identifier ChiCTR1900026225.

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.

Effects of combining rTMs and augmented reality gait adaptive training on walking function of patients with stroke based on three-dimensional gait analysis and sEMG: a randomized controlled trial

BACKGROUND

Augmented reality gait adaptive training (ARGAT) and repetitive transcranial magnetic stimulation (rTMS) have both demonstrated efficacy in improving lower limb motor function in survivors of stroke.

PURPOSE

To investigate the effects of combining rTMS and ARGAT on motor function in survivors of stroke.

METHODS

The experimental group received a combination of rTMS and ARGAT, while the control group received ARGAT alone. The interventions comprised a total of 20 sessions, conducted over four weeks with five consecutive daily sessions. Outcome measures included three-dimensional gait analysis (3DGA), surface electromyography (sEMG), Fugl-Meyer assessment for the lower extremity (FMA-LE), and the Berg Balance Scale (BBS).

RESULTS

Following the intervention, both groups showed significant improvements in walking speed, symmetry index, affected step length, affected stride length, FMA-LE, and BBS scores (p < .05). Furthermore, the experimental group demonstrated greater improvements in walking speed (F = 4.58, p = .040), cadence (F = 5.67, p = .023), affected step length (F = 5.79, p = .022), affected stride length (F = 4.84, p = .035), FMA-LE (Z = 2.43, p = .019), and BBS (F = 4.76, p = .036) compared to the control group. The experimental group demonstrated a significant improvement in the co-contraction index (CCI) of the knee joint (F = 14.88, p < .001), a change not observed in the control group (F = 2.16, p = .151). However, neither group showed significant alterations in CCI of the ankle joint (F = 1.58, p = .218), step width (F = 0.24, p = .630), unaffected step length (F = 0.22, p = .641), or unaffected stride length (F = 2.99, p = .093).

CONCLUSION

The combination of low-frequency rTMS and ARGAT demonstrated superior effects on motor function recovery compared to ARGAT alone in survivors of stroke.

The effects of combining repetitive transcranial magnetic stimulation with task-specific training on gait performance in individuals with Parkinson's disease: A review article

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor impairments, especially in the area of gait disturbances. Physiotherapy, with a focus on task-specific training, has demonstrated a level of efficacy as regards alleviating symptoms and enhancing functional capabilities in individuals with PD. Repetitive Transcranial Magnetic Stimulation (rTMS) has emerged as a potential therapeutic intervention for improving motor functions in individuals with PD.

AIMS

This review article aims to investigate the effects of combining rTMS with task-specific training on gait performance in individuals with PD.

MATERIALS AND METHODS

PubMed, Physiotherapy Evidence Database (PEDro), and Scopus were all searched for relevant studies. The focus of the search was on studies that investigated the efficacy of combining rTMS with task-specific training to improve gait performance in individuals with PD.

RESULTS

Four studies were identified as fulfilling the eligibility criteria and were included in the study. The combination of rTMS with specific treadmill training and weight-bearing exercises can significantly enhance walking efficiency, including improvements in walking speed, self-mobility, and step rate. In addition, the combination of rTMS and task-specific training, such as treadmill-based training, shows promise in enhancing gait performance in individuals with PD.

DISCUSSION AND CONCLUSION

High-frequency rTMS targeting the primary motor cortex (or M1) can result in improved walking speed, self-mobility, and step rate. However, limited research exists regarding low-frequency stimulation of the supplementary motor area (SMA) in individuals with gait issues. Further research is required to determine the optimal parameters of rTMS, such as strength, frequency, and duration of stimulation and it is worth considering the incorporation of additional training modalities, including cognitive exercises.

Neuromodulation techniques in poststroke motor impairment recovery: Efficacy, challenges, and future directions

Cerebrovascular accidents, also known as strokes, represent a major global public health challenge and contribute to substantial mortality, disability, and socioeconomic burden. Multidisciplinary approaches for poststroke therapies are crucial for recovering lost functions and adapting to new limitations. This review discusses the potential of neuromodulation techniques, repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation, spinal cord stimulation (SCS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), as innovative strategies for facilitating poststroke recovery. Neuromodulation is an emerging adjunct to conventional therapies that target neural plasticity to restore lost function and compensate for damaged brain areas. The techniques discussed in this review have different efficacies in enhancing neural plasticity, optimizing motor recovery, and mitigating poststroke impairments. Specifically, rTMS has shown significant promise in enhancing motor function, whereas SCS has shown potential in improving limb movement and reducing disability. Similarly, VNS, typically used to treat epilepsy, has shown promise in enhancing poststroke motor recovery, while DBS may be used to improve poststroke motor recovery and symptom mitigation. Further studies with standardized protocols are warranted to elucidate the efficacy of these methods and integrate them into mainstream clinical practice to optimize poststroke care.

Comparative efficacy of different repetitive transcranial magnetic stimulation protocols for lower extremity motor function in stroke patients: a network meta-analysis

Background

Lower extremity motor dysfunction is one of the most severe consequences after stroke, restricting functional mobility and impairing daily activities. Growing evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can improve stroke patients' lower extremity motor function. However, there is still controversy about the optimal rTMS protocol. Therefore, we compared and analyzed the effects of different rTMS protocols on lower extremity motor function in stroke patients using network meta-analysis (NMA).

Methods

We systematically searched CNKI, WanFang, VIP, CBM, PubMed, Embase, Web of Science, and Cochrane Library databases (from origin to 31 December 2023). Randomized controlled trials (RCTs) or crossover RCTs on rTMS improving lower extremity motor function in stroke patients were included. Two authors independently completed article screening, data extraction, and quality assessment. RevMan (version 5.4) and Stata (version 17.0) were used to analyze the data.

Results

A total of 38 studies with 2,022 patients were eligible for the NMA. The interventions included HFrTMS-M1, LFrTMS-M1, iTBS-Cerebellum, iTBS-M1, dTMS-M1, and Placebo. The results of NMA showed that LFrTMS-M1 ranked first in FMA-LE and speed, and HFrTMS-M1 ranked first in BBS, TUGT, and MEP amplitude. The subgroup analysis of FMA-LE showed that HFrTMS-M1 was the best stimulation protocol for post-stroke time > 1 month, and LFrTMS-M1 was the best stimulation protocol for post-stroke time ≤ 1 month.

Conclusion

Considering the impact of the stroke phase on the lower extremity motor function, the current research evidence shows that HFrTMS-M1 may be the preferred stimulation protocol to improve the lower extremity motor function of patients for post-stroke time > 1 month, and LFrTMS-M1 for post-stroke time ≤ 1 month. However, the above conclusion needs further analysis and validation by more high-quality RCTs.Systematic Review Registration:www.crd.york.ac.uk/prospero/, identifier (CRD42023474215).

Transcranial Direct Current Stimulation in the Treatment of Gait Disturbance in Post-Stroke Patients: An Overview of Systematic Reviews

INTRODUCTION

Transcranial direct current stimulation (tDCS) is a promising technique for brain modulation after a cerebrovascular accident (CVA). This treatment modality has been previously studied in the recovery of patients. The aim of this review is to analyse the evidence for the application of tDCS in the recovery of gait disturbance in stroke patients.

METHODS

This review was conducted according to the recommendations of the PRISMA statement. Three different electronic databases were searched for relevant results: PubMed, Scopus, and Cochrane, from 2015 to January 2022. We included reviews and meta-analyses that only considered randomised controlled trials (RCTs) that investigated the effects of transcranial direct current stimulation, in combination or not with other physiotherapy treatments, compared to no treatment, usual care, or alternative treatment on gait recovery. Our primary outcomes of interest were walking speed, mobility, and endurance; secondary outcomes included motor function.

RESULTS

Thirteen studies with a total of 195 RCTs were included. Data on population, outcome measures, protocols, and outcomes were extracted. The Amstar-2 scale and the GRADE system of certainty of evidence were used. Only one study received high certainty of evidence, 5 received low certainty of evidence, and 7 received critically low certainty of evidence. Moderate to low-quality evidence showed a beneficial effect of tDCS on gait parameters, but not significantly.

CONCLUSIONS

Although the tDCS produces positive changes in gait recovery in spatio-temporal parameters such as mobility, endurance, strength, and motor function, there is insufficient evidence to recommend this treatment. Higher-quality studies with larger sample sizes are needed for stronger conclusions.

Repetitive Transcranial Magnetic Stimulation in Stroke: A Literature Review of the Current Role and Controversies of Neurorehabilitation Through Electromagnetic Pulses

Repetitive transcranial magnetic stimulation (rTMS) is an effective method used for the treatment of various neurological diseases, including stroke, epilepsy, and movement disorders. The pathophysiological mechanism for the effect of TMS is not clear. In this literature review, we conducted a detailed search regarding the effect of rTMS on neurotransmission and neuronal plasticity through the modulation of neuronal excitability. Evidence suggests that intramolecular subatomic mechanisms, including genetic changes related to neuronal prevention and death, play an important role. We also discuss the use of rTMS in the rehabilitation of patients with stroke and its main complications, as well as alternative mechanisms related to recovery, emphasizing the findings of available evidence and touching on possible controversies and limitations of the method.

Repetitive transcranial magnetic stimulation for stroke rehabilitation: insights into the molecular and cellular mechanisms of neuroinflammation

Stroke is a leading cause of mortality and disability worldwide, with most survivors reporting dysfunctions of motor, sensation, deglutition, cognition, emotion, and speech, etc. Repetitive transcranial magnetic stimulation (rTMS), one of noninvasive brain stimulation (NIBS) techniques, is able to modulate neural excitability of brain regions and has been utilized in neurological and psychiatric diseases. Moreover, a large number of studies have shown that the rTMS presents positive effects on function recovery of stroke patients. In this review, we would like to summarized the clinical benefits of rTMS for stroke rehabilitation, including improvements of motor impairment, dysphagia, depression, cognitive function, and central post-stroke pain. In addition, this review will also discuss the molecular and cellular mechanisms underlying rTMS-mediated stroke rehabilitation, especially immune regulatory mechanisms, such as regulation of immune cells and inflammatory cytokines. Moreover, the neuroimaging technique as an important tool in rTMS-mediated stroke rehabilitation has been discussed, to better understanding the mechanisms underlying the effects of rTMS. Finally, the current challenges and future prospects of rTMS-mediated stroke rehabilitation are also elucidated with the intention to accelerate its widespread clinical application.

Applying transcranial magnetic stimulation to rehabilitation of poststroke lower extremity function and an improvement: Individual-target TMS

Stroke is the leading cause of disability globally in need of novel and effective methods of rehabilitation. Intermittent theta burst stimulation (iTBS) has been adopted as a Level B recommendation for lower limb spasticity in guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS). Nonetheless, the methodological differences and deficits of existing work bring about heterogenous results and therefore limit the universal clinical use of rTMS in lower extremity (LE) rehabilitation. The variation of stimulated targets across motor cortex contributes mainly to these heterogeneities. This narrative review includes studies of rTMS on LE motor function rehabilitation in patients after stroke until now. Some analyses of brain imaging and electromagnetic simulation and quantification through computational modeling were also performed. rTMS appears capable of fostering LE motor rehabilitation after stroke, but the actually stimulated targets are considerably bias making it difficult to confirm effectiveness. The main reason for this phenomenon is probably inaccurate targeting of motor cortical leg representation. An underlying updated method is proposed as Individual-Target TMS (IT-TMS) combined with brain imaging. rTMS is a promising validated method for LE function regaining. Future studies should systematically compare the effects of IT-TMS with traditional rTMS using large samples in random clinical trials. This article is categorized under: Neuroscience > Clinical Neuroscience.

Clinical Implementation of Noninvasive Brain Stimulation in an Outpatient Neurorehabilitation Program

ABSTRACT

Motor, speech, and cognitive impairments are the most common consequences of neurological disorders. There has been an increasing interest in the use of noninvasive brain stimulation techniques such as transcranial direct current stimulation and transcranial magnetic stimulation to augment the effects of neurorehabilitation. Numerous research studies have shown that transcranial direct current stimulation and transcranial magnetic stimulation are highly promising neuromodulation tools that can work as adjuvants to standard neurorehabilitation services, including physical therapy, occupational therapy, and speech-language pathology. However, to date, there are vast differences in methodology in studies including noninvasive brain stimulation parameters, patient characteristics, time point of intervention after injury, and outcome measures, making it difficult to translate and implement transcranial direct current stimulation and transcranial magnetic stimulation in the clinical setting. Despite this, a series of principles are thought to underlie the effectiveness of noninvasive brain stimulation techniques. We developed a noninvasive brain stimulation rehabilitation program using these principles to provide best practices for applying transcranial direct current stimulation and/or transcranial magnetic stimulation as rehabilitation adjuvants in the clinical setting to help improve neurorehabilitation outcomes. This article outlines our approach, philosophy, and experience.

[Experience of using rhythmic transcranial magnetic stimulation, extracorporeal shock wave therapy and botulinotherapy in individual motor recovery programs in patients with spastic paresis of the lower limb]

Walking disorder is one of the most frequent consequences of stroke and traumatic brain injury, occurring in 80% of cases. Spastic paresis of the muscles of the lower extremity is the cause formed in 20-40% of patients within a few weeks after brain damage. In this case, a complex of symptoms occurs: motor deficiency (muscle paresis), increased muscle tone (spasticity), biomechanical changes in muscles, joints and surrounding tissues, contractures. Recovery of walking is a difficult task due to the peculiarities of its organization in the norm. At the same time, changes occurring in the muscles of the lower limb after a stroke, their modular reorganization, the formation of various pathological patterns, violation of the regulation of movements by the central nervous system, rapidly occurring changes in muscles, ligaments, complicate this process. Improving walking is one of the most important priorities of rehabilitation. Already at the second (stationary) stage of rehabilitation, patients have a lack of proper support on the lower limb, which inevitably leads to excessive load on the second limb, a change in the body scheme, incorrect foot placement, violation of the mechanics of walking (moving from heel to toe) due to plantar flexion / turn of the foot, etc. All this makes patients dependent on outside help, and walking unsafe, increases the risk of falls and complications (arthropathy, contracture, etc.). In this regard, it is important to timely diagnose the totality of changes in the lower limb and create optimal comprehensive rehabilitation programs using highly effective treatment methods aimed at reducing the severity of the motor defect, reducing spasticity and preventing complications. The article discusses the place of rhythmic transcranial magnetic stimulation, extracorporeal shock wave therapy and botulinum therapy during rehabilitation in patients with spastic paresis of the lower limb after a stroke. The results of the protocol of clinical approbation «Complex rehabilitation of patients with lower limb spasticity after focal brain damage at the second stage of medical rehabilitation» are presented.

Repetitive transcranial magnetic stimulation of the primary motor cortex in stroke survivors-more than motor rehabilitation: A mini-review

Stroke is a leading cause of morbidity and mortality among elderly populations worldwide. During the early phase of stroke, restoring blood circulation is of utmost importance to protect neurons from further injury. Once the initial condition is stabilized, various rehabilitation techniques can be applied to help stroke survivors gradually regain their affected functions. Among these techniques, transcranial magnetic stimulation (TMS) has emerged as a novel method to assess and modulate cortical excitability non-invasively and aid stroke survivors in the rehabilitation process. Different cortical regions have been targeted using TMS based on the underlying pathology and distorted function. Despite the lack of a standard operational procedure, repetitive TMS (rTMS) of the primary motor cortex (M1) is considered a promising intervention for post-stroke motor rehabilitation. However, apart from the motor response, mounting evidence suggests that M1 stimulation can be employed to treat other symptoms such as dysphagia, speech impairments, central post-stroke pain, depression, and cognitive dysfunction. In this mini-review, we summarize the therapeutic uses of rTMS stimulation over M1 in stroke survivors and discuss the potential mechanistic rationale behind it.

The effects of robot-assisted gait training combined with non-invasive brain stimulation on lower limb function in patients with stroke and spinal cord injury: A systematic review and meta-analysis

Objective:

This study aimed to investigate the effect of robot-assisted gait training (RAGT) therapy combined with non-invasive brain stimulation (NIBS) on lower limb function in patients with stroke and spinal cord injury (SCI).

Data sources

PubMed, Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Web of Science were searched.

Study selection

Randomized controlled trials (RCTs) published as of 3 March 2021. RCTs evaluating RAGT combined with NIBS, such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), for lower limb function (e.g., Fugl-Meyer assessment for patients with stroke) and activities (i.e., gait velocity) in patients with stroke and SCI were included.

Data extraction

Two reviewers independently screened the records, extracted the data, and assessed the risk of bias.

Data synthesis

A meta-analysis of five studies (104 participants) and risk of bias were conducted. Pooled estimates demonstrated that RAGT combined with NIBS significantly improved lower limb function [standardized mean difference (SMD) = 0.52; 95% confidence interval (CI) = 0.06–0.99] but not lower limb activities (SMD = −0.13; 95% CI = −0.63–0.38). Subgroup analyses also failed to find a greater improvement in lower limb function of RAGT with tDCS compared to sham stimulation. No significant differences between participant characteristics or types of NIBS were observed.

Conclusion

This meta-analysis demonstrated that RAGT therapy in combination with NIBS was effective in patients with stroke and SCI. However, a greater improvement in lower limb function and activities were not observed using RAGT with tDCS compared to sham stimulation.

The effects of repetitive transcranial magnetic stimulation on standing balance and walking in older adults with age-related neurological disorders: a systematic review and meta-analysis

BACKGROUND

Considerable evidence showed that repetitive transcranial magnetic stimulation (rTMS) can improve standing balance and walking performance in older adults with age-related neurological disorders. We here thus completed a systematic review and meta-analysis to quantitatively examine such benefits of rTMS.

METHODS

A search strategy based on the PICOS principle was used to obtain the literature in four databases. The screening and assessments of quality and risk of bias in the included studies were independently completed by two researchers. Outcomes included scales related to standing balance, Timed Up and Go (TUG) time, and walking speed/time/distance.

RESULTS

Twenty-three studies consisting of 532 participants were included, and the meta-analysis was completed on 21 of these studies. The study quality was good. Compared to control, rTMS induced both short-term (≤3 days after last intervention session) and long-term (≥1 month following last intervention session) significant improvements in balance scales (e.g., Berg Balance Scale), TUG time, and walking speed/time/distance (short-term: standardized mean difference [SMD]=0.26~0.34, 95% confidence interval [CI]=0.05~0.62; long-term: SMD=0.40~0.44, 95% CI=0.04~0.79) for both PD and stroke cohorts. Subgroup analyses suggested that greater than nine sessions of high-frequency rTMS targeting primary motor cortex with greater than 3000 pulses per week can maximize such benefits. Only few mild-to-moderate adverse events/side effects were reported, which were similar between rTMS and control group.

CONCLUSION

The results suggest that rTMS holds promise to improve balance and walking performance in older adults with age-related neurological disorders. Future studies with more rigorous design are needed to confirm the observations in this work.

Non-invasive brain stimulation for improving gait, balance, and lower limbs motor function in stroke

Objectives

This systematic review and meta-analysis aim to summarize and analyze the available evidence of non-invasive brain stimulation/spinal cord stimulation on gait, balance and/or lower limb motor recovery in stroke patients.

Methods

The PubMed database was searched from its inception through to 31/03/2021 for randomized controlled trials investigating repetitive transcranial magnetic stimulation or transcranial/trans-spinal direct current/alternating current stimulation for improving gait, balance and/or lower limb motor function in stroke patients.

Results

Overall, 25 appropriate studies (including 657 stroke subjects) were found. The data indicates that non-invasive brain stimulation/spinal cord stimulation is effective in supporting recovery. However, the effects are inhomogeneous across studies: (1) transcranial/trans-spinal direct current/alternating current stimulation induce greater effects than repetitive transcranial magnetic stimulation, and (2) bilateral application of non-invasive brain stimulation is superior to unilateral stimulation.

Conclusions

The current evidence encourages further research and suggests that more individualized approaches are necessary for increasing effect sizes in stroke patients.

Associative cued asynchronous BCI induces cortical plasticity in stroke patients

OBJECTIVE

We propose a novel cue-based asynchronous brain-computer interface(BCI) for neuromodulation via the pairing of endogenous motor cortical activity with the activation of somatosensory pathways.

METHODS

The proposed BCI detects the intention to move from single-trial EEG signals in real time, but, contrary to classic asynchronous-BCI systems, the detection occurs only during time intervals when the patient is cued to move. This cue-based asynchronous-BCI was compared with two traditional BCI modes (asynchronous-BCI and offline synchronous-BCI) and a control intervention in chronic stroke patients. The patients performed ankle dorsiflexion movements of the paretic limb in each intervention while their brain signals were recorded. BCI interventions decoded the movement attempt and activated afferent pathways via electrical stimulation. Corticomotor excitability was assessed using motor-evoked potentials in the tibialis-anterior muscle induced by transcranial magnetic stimulation before, immediately after, and 30 min after the intervention.

RESULTS

The proposed cue-based asynchronous-BCI had significantly fewer false positives/min and false positives/true positives (%) as compared to the previously developed asynchronous-BCI. Linear-mixed-models showed that motor-evoked potential amplitudes increased following all BCI modes immediately after the intervention compared to the control condition (p <0.05). The proposed cue-based asynchronous-BCI resulted in the largest relative increase in peak-to-peak motor-evoked potential amplitudes(141% ± 33%) among all interventions and sustained it for 30 min(111% ± 33%).

INTERPRETATION

These findings prove the high performance of a newly proposed cue-based asynchronous-BCI intervention. In this paradigm, individuals receive precise instructions (cue) to promote engagement, while the timing of brain activity is accurately detected to establish a precise association with the delivery of sensory input for plasticity induction.

Non-invasive brain stimulation in rehabilitation

Non-invasive brain stimulation (NIBS) has been seen more common in rehabilitation settings. It can be used for the treatment of stroke, spinal cord injury, traumatic brain injury and multiple sclerosis, as well as for some diagnostic neurophysiological measurements. Two major modalities of NIBS are transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). As an add-on therapy to conventional rehabilitative treatments, the main goal of NIBS is to create neuromodulation by inhibiting or activating neural activity in the targeted cortical region. Indications for therapeutic NIBS in neurorehabilitation are motor recovery, aphasia, neglect, dysphagia, cognitive disorders, spasticity, and central pain. The NIBS can be regarded a safe technique with appropriate patient selection and defined treatment parameters. This review provides an overview on NIBS modalities, specifically TMS and tDCS, the working mechanisms, the stimulation techniques, areas of use, neuronavigation systems and safety considerations.

Efficacy of repetitive transcranial magnetic stimulation for improving lower limb function in individuals with neurological disorders: A systematic review and meta-analysis of randomized sham-controlled trials

OBJECTIVE

To determine the efficacy of repetitive transcranial magnetic stimulation vs sham stimulation on improving lower-limb functional outcomes in individuals with neurological disorders.

DATA SOURCES

PubMed, CINAHL, Embase and Scopus databases were searched from inception to 31 March 2020 to identify papers (n = 1,198). Two researchers independently reviewed studies for eligibility. Randomized clinical trials with parallel-group design, involving individuals with neurological disorders, including lower-limb functional outcome measures and published in scientific peer-reviewed journals were included.

DATA EXTRACTION

Two researchers independently screened eligible papers (n = 27) for study design, clinical population characteristics, stimulation protocol and relevant outcome measures, and assessed study quality.

DATA SYNTHESIS

Studies presented a moderate risk of selection, attrition and reporting bias. An overall effect of repetitive transcranial magnetic stimulation was found for outcomes: gait (effect size [95% confidence interval; 95% CI]: 0.51 [0.29; 0.74], p = 0.003) and muscle strength (0.99 [0.40; 1.58], p = 0.001) and disorders: stroke (0.20 [0.00; 0.39], p = 0.05), Parkinson's disease (1.01 [0.65; 1.37], p = 0.02) and spinal cord injury (0.50 [0.14; 0.85], p = 0.006), compared with sham. No effect was found for outcomes: mobility and balance.

CONCLUSION

Supplementary repetitive transcranial magnetic stimulation may promote rehabilitation focused on ambulation and muscle strength and overall lower-limb functional recovery in individuals with stroke, Parkinson's disease and spinal cord injury. Further evidence is needed to extrapolate these findings.

The Effect of Repetitive Transcranial Magnetic Stimulation on Lower-Limb Motor Ability in Stroke Patients: A Systematic Review

Repetitive transcranial magnetic stimulation (rTMS) is fundamental in inducing neuroplastic changes and promoting brain function restoration. Nevertheless, evidence based on the systematic assessment of the implication of rTMS in stroke patients is inadequate. This study aimed to evaluate the value of rTMS in the treatment of lower-limb motor dysfunction in stroke patients via gait characteristics. The electronic literature search was performed in ScienceDirect, Google Scholar, and PubMed databases using "repetitive transcranial magnetic stimulation," "gait," and "stroke" between 2000 and 2020. By screening all the identified studies, a total of 10 studies covering 257 stroke patients were included by matching the inclusion criteria, involving both rTMS with high (≥5 Hz) and low frequency (<5 Hz). Despite the limited study number and relatively high risk of bias, the results of this review primarily confirmed the enhancing effects of rTMS on the lower-limb motor ability (e.g., gait and balance) of stroke patients. In addition, 15- to 20-min course of rTMS for 2 to 3 weeks was found to be the most common setting, and 1 Hz and 10 Hz were the most commonly used low and high frequencies, respectively. These results might have significant clinical applications for patients with weakened lower-limb mobility after a stroke. Nevertheless, more rigorous studies in this field are much warranted. Systematic Review Registration:https://inplasy.com/, identifier INPLASY202180079.

Velocity of the Body Center of Mass During Walking on Split-Belt Treadmill

ABSTRACT

Walking on split-belt treadmills (each belt rotating at a different velocity) has inspired a growing number of researchers to study gait adaptation and rehabilitation. An overlooked peculiarity of this artificial form of gait is that the mean velocity adopted by the participant, considered as a whole system represented by the body Center of Mass, can be different from the mean velocity of the two belts. Twelve healthy adults (21-34 yrs) were requested to walk for 15 mins on a treadmill with belts rotating at 0.4 and 1.2 m sec-1, respectively (mean = 0.8 m sec-1). Each belt was supported by four 3-dimensional force sensors. For each participant, six strides were analyzed during the 1st and the 15th minute of the trial. The mean Center of Mass velocity was computed as the sum of the velocities of each belt weighted by the percentage of time during which the resulting forces, underlying the accelerations of the Center of Mass, originated from each belt. Across early and late observations, the median Center of Mass velocities were 0.72 and 0.67 m sec-1, respectively (P < 0.05). Therefore, the real velocity of the Center of Mass and its time course should be individually assessed when studying walking on split-belt treadmills.

Induction of Neural Plasticity Using a Low-Cost Open Source Brain-Computer Interface and a 3D-Printed Wrist Exoskeleton

Brain-computer interfaces (BCIs) have been proven to be useful for stroke rehabilitation, but there are a number of factors that impede the use of this technology in rehabilitation clinics and in home-use, the major factors including the usability and costs of the BCI system. The aims of this study were to develop a cheap 3D-printed wrist exoskeleton that can be controlled by a cheap open source BCI (OpenViBE), and to determine if training with such a setup could induce neural plasticity. Eleven healthy volunteers imagined wrist extensions, which were detected from single-trial electroencephalography (EEG), and in response to this, the wrist exoskeleton replicated the intended movement. Motor-evoked potentials (MEPs) elicited using transcranial magnetic stimulation were measured before, immediately after, and 30 min after BCI training with the exoskeleton. The BCI system had a true positive rate of 86 ± 12% with 1.20 ± 0.57 false detections per minute. Compared to the measurement before the BCI training, the MEPs increased by 35 ± 60% immediately after and 67 ± 60% 30 min after the BCI training. There was no association between the BCI performance and the induction of plasticity. In conclusion, it is possible to detect imaginary movements using an open-source BCI setup and control a cheap 3D-printed exoskeleton that when combined with the BCI can induce neural plasticity. These findings may promote the availability of BCI technology for rehabilitation clinics and home-use. However, the usability must be improved, and further tests are needed with stroke patients.

Repetitive transcranial magnetic stimulation for lower extremity motor function in patients with stroke: a systematic review and network meta-analysis

Transcranial magnetic stimulation, a type of noninvasive brain stimulation, has become an ancillary therapy for motor function rehabilitation. Most previous studies have focused on the effects of repetitive transcranial magnetic stimulation (rTMS) on motor function in stroke patients. There have been relatively few studies on the effects of different modalities of rTMS on lower extremity motor function and corticospinal excitability in patients with stroke. The MEDLINE, Embase, Cochrane Library, ISI Science Citation Index, Physiotherapy Evidence Database, China National Knowledge Infrastructure Library, and ClinicalTrials.gov databases were searched. Parallel or crossover randomized controlled trials that addressed the effectiveness of rTMS in patients with stroke, published from inception to November 28, 2019, were included. Standard pairwise meta-analysis was conducted using R version 3.6.1 with the “meta” package. Bayesian network analysis using the Markov chain Monte Carlo algorithm was conducted to investigate the effectiveness of different rTMS protocol interventions. Network meta-analysis results of 18 randomized controlled trials regarding lower extremity motor function recovery revealed that low-frequency rTMS had better efficacy in promoting lower extremity motor function recovery than sham stimulation. Network meta-analysis results of five randomized controlled trials demonstrated that high-frequency rTMS led to higher amplitudes of motor evoked potentials than low-frequency rTMS or sham stimulation. These findings suggest that rTMS can improve motor function in patients with stroke, and that low-frequency rTMS mainly affects motor function, whereas high-frequency rTMS increases the amplitudes of motor evoked potentials. More high-quality randomized controlled trials are needed to validate this conclusion. The work was registered in PROSPERO (registration No. CRD42020147055) on April 28, 2020.

Individualized Responses to Ipsilesional High-Frequency and Contralesional Low-Frequency rTMS in Chronic Stroke: A Pilot Study to Support the Individualization of Neuromodulation for Rehabilitation

Background: In this pilot study, we examined the effects of ipsilesional high-frequency rTMS (iHF-rTMS) and contralesional low-frequency rTMS (cLF-rTMS) applied via a double-cone coil on neurophysiological and gait variables in patients with chronic stroke.

Objective/Hypothesis: To determine the group and individual level effects of two types of stimulation to better individualize neuromodulation for rehabilitation.

Methods: Using a randomized, within-subject, double-blind, sham-controlled trial with 14 chronic stroke participants iHF-rTMS and cLF-rTMS were applied via a double-cone coil to the tibialis anterior cortical representation. Neurophysiological and gait variables were compared pre-post rTMS.

Results: A small effect of cLF-rTMS indicated increased MEP amplitudes (Cohen’s D; cLF-rTMS, d = −0.30). Group-level analysis via RMANOVA showed no significant group effects of stimulation (P > 0.099). However, secondary analyses of individual data showed a high degree of response variability to rTMS. Individual percent changes in resting motor threshold and normalized MEP latency correlated with changes in gait propulsive forces and walking speed (iHF-rTMS, nLAT:Pp, R = 0.632 P = 0.015; cLF-rTMS, rMT:SSWS, R = −0.557, P = 0.039; rMT:Pp, R = 0.718, P = 0.004).

Conclusions: Changes in propulsive forces and walking speed were seen in some individuals that showed neurophysiological changes in response to rTMS. The neurological consequences of stroke are heterogeneous making a “one type fits all” approach to neuromodulation for rehabilitation unlikely. This pilot study suggests that an individual’s unique response to rTMS should be considered before the application/selection of neuromodulatory therapies. Before neuromodulatory therapies can be incorporated into standard clinical practice, additional work is needed to identify biomarkers of response and how best to prescribe neuromodulation for rehabilitation for post-stroke gait.

These legs were made for propulsion: advancing the diagnosis and treatment of post-stroke propulsion deficits

Advances in medical diagnosis and treatment have facilitated the emergence of precision medicine. In contrast, locomotor rehabilitation for individuals with acquired neuromotor injuries remains limited by the dearth of (i) diagnostic approaches that can identify the specific neuromuscular, biomechanical, and clinical deficits underlying impaired locomotion and (ii) evidence-based, targeted treatments. In particular, impaired propulsion by the paretic limb is a major contributor to walking-related disability after stroke; however, few interventions have been able to target deficits in propulsion effectively and in a manner that reduces walking disability. Indeed, the weakness and impaired control that is characteristic of post-stroke hemiparesis leads to heterogeneous deficits that impair paretic propulsion and contribute to a slow, metabolically-expensive, and unstable gait. Current rehabilitation paradigms emphasize the rapid attainment of walking independence, not the restoration of normal propulsion function. Although walking independence is an important goal for stroke survivors, independence achieved via compensatory strategies may prevent the recovery of propulsion needed for the fast, economical, and stable gait that is characteristic of healthy bipedal locomotion. We posit that post-stroke rehabilitation should aim to promote independent walking, in part, through the acquisition of enhanced propulsion. In this expert review, we present the biomechanical and functional consequences of post-stroke propulsion deficits, review advances in our understanding of the nature of post-stroke propulsion impairment, and discuss emerging diagnostic and treatment approaches that have the potential to facilitate new rehabilitation paradigms targeting propulsion restoration.

Functional muscle strength recovery from nail gun injury to the primary motor cortex

Aim: Functional recovery following injury to the primary motor cortex is an uncommon phenomenon, given the limited ability of neurons of the adult central nervous system to regenerate. Case description: We report on a patient with near complete functional muscle strength recovery from a marked monoparesis due to nail gun injury to the medial primary motor cortex. Besides surgical decision-making, we discuss possible related mechanisms and current challenges in the regenerative processes responsible for the functional recovery. Discussion: To achieve a favorable outcome, surgical decision-making to prevent secondary damage is of upmost importance. Lesion-induced inflammatory response may potentiate endogenous neurogenesis and neuronal plasticity and potentially contribute to the regenerative process involved.

Repetitive transcranial magnetic stimulation in stroke rehabilitation: review of the current evidence and pitfalls

Acute brain ischemia causes changes in several neural networks and related cortico-subcortical excitability, both in the affected area and in the apparently spared contralateral hemisphere. The modulation of these processes through modern techniques of noninvasive brain stimulation, namely repetitive transcranial magnetic stimulation (rTMS), has been proposed as a viable intervention that could promote post-stroke clinical recovery and functional independence. This review provides a comprehensive summary of the current evidence from the literature on the efficacy of rTMS applied to different clinical and rehabilitative aspects of stroke patients. A total of 32 meta-analyses published until July 2019 were selected, focusing on the effects on motor function, manual dexterity, walking and balance, spasticity, dysphagia, aphasia, unilateral neglect, depression, and cognitive function after a stroke. Only conventional rTMS protocols were considered in this review, and meta-analyses focusing on theta burst stimulation only were excluded. Overall, both HF-rTMS and LF-rTMS have been shown to be safe and well-tolerated. In addition, the current literature converges on the positive effect of rTMS in the rehabilitation of all clinical manifestations of stroke, except for spasticity and cognitive impairment, where definitive evidence of efficacy cannot be drawn. However, routine use of a specific paradigm of stimulation cannot be recommended yet due to a significant level of heterogeneity of the studies in terms of protocols to be set and outcome measures that have to be used. Future studies need to preliminarily evaluate the most promising protocols before going on to multicenter studies with large cohorts of patients in order to achieve a definitive translation into daily clinical practice.

Repetitive transcranial magnetic stimulation in stroke rehabilitation: review of the current evidence and pitfalls

Acute brain ischemia causes changes in several neural networks and related cortico-subcortical excitability, both in the affected area and in the apparently spared contralateral hemisphere. The modulation of these processes through modern techniques of noninvasive brain stimulation, namely repetitive transcranial magnetic stimulation (rTMS), has been proposed as a viable intervention that could promote post-stroke clinical recovery and functional independence. This review provides a comprehensive summary of the current evidence from the literature on the efficacy of rTMS applied to different clinical and rehabilitative aspects of stroke patients. A total of 32 meta-analyses published until July 2019 were selected, focusing on the effects on motor function, manual dexterity, walking and balance, spasticity, dysphagia, aphasia, unilateral neglect, depression, and cognitive function after a stroke. Only conventional rTMS protocols were considered in this review, and meta-analyses focusing on theta burst stimulation only were excluded. Overall, both HF-rTMS and LF-rTMS have been shown to be safe and well-tolerated. In addition, the current literature converges on the positive effect of rTMS in the rehabilitation of all clinical manifestations of stroke, except for spasticity and cognitive impairment, where definitive evidence of efficacy cannot be drawn. However, routine use of a specific paradigm of stimulation cannot be recommended yet due to a significant level of heterogeneity of the studies in terms of protocols to be set and outcome measures that have to be used. Future studies need to preliminarily evaluate the most promising protocols before going on to multicenter studies with large cohorts of patients in order to achieve a definitive translation into daily clinical practice.