Transcranial magnetic stimulation combined with upper-limb training for improving function after stroke: A systematic review and meta-analysis

Changes in the Relationship Between Gray Matter, Functional Parameters, and Quality of Life in Patients with a Post-Stroke Spastic Upper Limb After Single-Event Multilevel Surgery: Six-Month Results from a Randomized Trial

Introduction: Advanced magnetic resonance imaging (MRI) techniques in neuroplasticity evaluations provide important information on stroke disease and the underlying mechanisms of neuronal recovery. It has been observed that gray matter density or volume in brain regions closely related to motor function can be a valuable indicator of the response to treatment. Objective: To compare structural MRI-evaluated gray matter volume changes in patients with post-stroke upper limb spasticity for >1 year between those undergoing surgery and those treated with botulinum toxin A (BoNT-A) and to relate these findings to upper limb function and quality of life outcomes. Materials and Methods: Design. A two-arm controlled and randomized clinical trial in patients with post-stroke upper limb spasticity. Participants. Thirty post-stroke patients with spastic upper limbs. Intervention. Participants were randomly assigned (1:1 allocation ratio) for surgery (experimental group) or treatment with BoNT-A (control group). Main outcome measures. The functional parameters were analyzed with Fugl-Meyer, Zancolli, Keenan, House, Ashworth, pain visual analogue, and hospital anxiety and depression scales. Quality of life was evaluated using SF-36 and Newcastle stroke-specific quality of life scales. The carer burden questionnaire was also applied. Clinical examinations and MRI scans were performed at baseline and at six months post-intervention. Correlations between brain volume/thickness and predictors of interest were examined across evaluations and groups. Results: Five patients were excluded due to the presence of intracranial implants. Eleven patients were excluded from analyses since they were late dropouts. Changes were observed in the experimental group but not in the control group. Between baseline and six months, gray matter volume was augmented at the hippocampus and gyrus rectus and cortical thickness was increased at the frontal pole, occipital gyrus, and insular cortex, indicating anatomical changes in key areas related to motor and behavioral adaptation These changes were significantly related to subjective pain, Ashworth spasticity scale, and Newcastle quality of life scores, and marginally related to the carer burden score. Conclusions: The structural analysis of gray matter by MRI revealed differences in patients with post-stroke sequelae undergoing different therapies. Gray matter volume and cortical thickness measurements showed significant improvements in the surgery group but not in the BoNT-A group. Volume was increased in areas associated with motor and sensory functions, suggesting a neuroprotective or regenerative effect of upper limb surgery.

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].

Molecular Changes in the Ischemic Brain as Non-Invasive Brain Stimulation Targets-TMS and tDCS Mechanisms, Therapeutic Challenges, and Combination Therapies

Ischemic stroke is one of the leading causes of death and disability. As the currently used neurorehabilitation methods present several limitations, the ongoing research focuses on the use of non-invasive brain stimulation (NIBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). NIBS methods were demonstrated to modulate neural excitability and improve motor and cognitive functioning in neurodegenerative diseases. However, their mechanisms of action are not fully elucidated, and the clinical outcomes are often unpredictable. This review explores the molecular processes underlying the effects of TMS and tDCS in stroke rehabilitation, including oxidative stress reduction, cell death, stimulation of neurogenesis, and neuroprotective phenotypes of glial cells. A highlight is put on the newly emerging therapeutic targets, such as ferroptotic and pyroptotic pathways. In addition, the issue of interindividual variability is discussed, and the role of neuroimaging techniques is investigated to get closer to personalized medicine. Furthermore, translational challenges of NIBS techniques are analyzed, and limitations of current clinical trials are investigated. The paper concludes with suggestions for further neurorehabilitation stroke treatment, putting the focus on combination and personalized therapies, as well as novel protocols of brain stimulation techniques.

Ultra-early navigated transcranial magnetic stimulation for perioperative stroke: anatomo-functional report

Navigated repetitive transmagnetic stimulation is a non-invasive and safe brain activity modulation technique. When combined with the classical rehabilitation process in stroke patients it has the potential to enhance the overall neurologic recovery. We present a case of a peri-operative stroke, treated with ultra-early low frequency navigated repetitive transmagnetic stimulation over the contralesional hemisphere. The patient received low frequency navigated repetitive transmagnetic stimulation within 12 hours of stroke onset for seven consecutive days and a significant improvement in his right sided weakness was noticed and he was discharge with normal power. This was accompanied by an increase in the number of positive responses evoked by navigated repetitive transmagnetic stimulation and a decrease of the resting motor thresholds at a cortical level. Subcortically, a decrease in the radial, axial, and mean diffusivity were recorded in the ipsilateral corticospinal tract and an increase in fractional anisotropy, axial diffusivity, and mean diffusivity was observed in the interhemispheric fibers of the corpus callosum responsible for the interhemispheric connectivity between motor areas. Our case demonstrates clearly that ultra-early low frequency navigated repetitive transmagnetic stimulation applied to the contralateral motor cortex can lead to significant clinical motor improvement in patients with subcortical stroke.

Testing spasticity mechanisms in chronic stroke before and after intervention with contralesional motor cortex 1 Hz rTMS and physiotherapy

BACKGROUND

Previous studies showed that repetitive transcranial magnetic stimulation (rTMS) reduces spasticity after stroke. However, clinical assessments like the modified Ashworth scale, cannot discriminate stretch reflex-mediated stiffness (spasticity) from passive stiffness components of resistance to muscle stretch. The mechanisms through which rTMS might influence spasticity are also not understood.

METHODS

We measured the effects of contralesional motor cortex 1 Hz rTMS (1200 pulses + 50 min physiotherapy: 3×/week, for 4-6 weeks) on spasticity of the wrist flexor muscles in 54 chronic stroke patients using a hand-held dynamometer for objective quantification of the stretch reflex response. In addition, we measured the excitability of three spinal mechanisms thought to be related to post-stroke spasticity: post-activation depression, presynaptic inhibition and reciprocal inhibition before and after the intervention. Effects on motor impairment and function were also assessed using standardized stroke-specific clinical scales.

RESULTS

The stretch reflex-mediated torque in the wrist flexors was significantly reduced after the intervention, while no change was detected in the passive stiffness. Additionally, there was a significant improvement in the clinical tests of motor impairment and function. There were no significant changes in the excitability of any of the measured spinal mechanisms.

CONCLUSIONS

We demonstrated that contralesional motor cortex 1 Hz rTMS and physiotherapy can reduce the stretch reflex-mediated component of resistance to muscle stretch without affecting passive stiffness in chronic stroke. The specific physiological mechanisms driving this spasticity reduction remain unresolved, as no changes were observed in the excitability of the investigated spinal mechanisms.

Investigation of the efficacy of low-frequency repetitive transcranial magnetic stimulation on upper-limb motor recovery in subacute ischemic stroke without cortical involvement: a protocol paper for a multi-center, double-blind randomized controlled trial

Introduction

The incidence of stroke is increasing steadily due to factors such as population aging. Approximately 80% of stroke survivors have motor disorders affecting their daily lives. Repetitive transcranial magnetic stimulation (rTMS) has been reported to maximize functional recovery after stroke along with exercise intervention in upper limb rehabilitation treatment. However, whether rTMS affects the recovery of upper limb function in patients with stroke remains unclear. Therefore, in this trial, we will investigate the efficacy of low-frequency rTMS in patients with subcortical and brainstem ischemic stroke.

Methods

This study has been designed as a multi-center, double-blind, randomized controlled trial to compare the efficacy of low-frequency rTMS over the contralesional M1 with sham stimulation. Overall, 88 participants will be allocated to the intervention or control group in a 1:1 ratio, with stratification according to their initial upper extremity Fugl-Meyer assessment (UE-FMA) score. The participants will receive either 30 min of real rTMS (intervention group) or sham rTMS (control group), followed by 30 min of occupational therapy for 10 consecutive workdays. All the participants will receive the same amount of rehabilitation therapy throughout the intervention period. Evaluations will be performed at baseline (T0), at the end of treatment (T1), and 4 weeks after the end of treatment (T2), including the box and block test (BBT), UE-FMA, Korean version of the Modified Barthel Index, and NIH Stroke Scale scores, Finger tapping test, Brunnstrom stage, modified Ashworth scale, and grip strength. The primary outcome will be the change in the BBT score between T0 and T2.

Conclusion

This study will provide evidence on the efficacy of low-frequency rTMS in motor function recovery of the upper limb in patients with subacute, subcortical, and brainstem ischemic stroke.

Clinical trial registration

ClinicalTrials.gov, identifier [NCT05535504].

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.

Does noninvasive brain stimulation combined with other therapies improve upper extremity motor impairment, functional performance, and participation in activities of daily living after stroke? A systematic review and meta-analysis of randomized controlled trial

BACKGROUND

Several studies have investigated the effect of noninvasive brain stimulation (NIBS) on upper limb motor function in stroke, but the evidence so far is conflicting.

OBJECTIVE

We aimed to determine the effect of NIBS on upper limb motor impairment, functional performance, and participation in activities of daily living after stroke.

METHOD

Literature search was conducted for randomized controlled trials (RCTs) assessing the effect of "tDCS" or "rTMS" combined with other therapies on upper extremity motor recovery after stroke. The outcome measures were Fugl-Meyer Assessment of Upper Extremity (FMA-UE), Wolf Motor Function Test (WMFT), and Barthel Index (BI). The mean difference (MD) and 95%CI were estimated for motor outcomes. Cochrane risk of bias tool was used to assess the quality of evidence.

RESULT

Twenty-five RCTs involving 1102 participants were included in the review. Compared to sham stimulation, NIBS combined with other therapies has effectively improved FMA-UE (MD0.97 [95%CI, 0.09 to 1.86; p = .03]) and BI score (MD9.11 [95%CI, 2.27 to 15.95; p = .009]) in acute/sub-acute stroke (MD1.73 [95%CI, 0.61 to 2.85; p = .003]) but unable to modify FMA-UE score in chronic stroke (MD-0.31 [95%CI, -1.77 to 1.15; p = .68]). Only inhibitory (MD3.04 [95%CI, 1.76 to 4.31; I² = 82%, p < .001] protocol is associated with improved FMA-UE score. Twenty minutes of stimulation/session for ≥20 sessions was found to be effective in improving FMA-UE score (Stimulation time: ES0.45; p ≤ .001; Sessions: ES0.33; p ≤ .001). The NIBS did not produce any significant improvement in WMFT as compared to sham NIBS (MD0.91 [95% CI, -0.89 to 2.70; p = .32]).

CONCLUSION

Moderate to high-quality evidence suggested that NIBS combined with other therapies is effective in improving upper extremity motor impairment and participation in activities of daily living after acute/sub-acute stroke.

Recovery of Patients With Upper Limb Paralysis Due to Stroke Who Underwent Intervention Using Low-Frequency Repetitive Transcranial Magnetic Stimulation Combined With Occupational Therapy: A Retrospective Cohort Study

OBJECTIVES

The combination of repetitive transcranial magnetic stimulation (rTMS) and motor practice is based on the theory of neuromodulation and use-dependent plasticity. Predictive planning of occupational therapy (OT) is important for patients with rTMS conditioning. Recovery characteristics based on the severity of pretreatment upper extremity paralysis can guide the patient's practice plan for using the paretic hand. Therefore, we evaluated the recovery of patients with upper limb paralysis due to stroke who underwent a novel intervention of rTMS combined with OT (NEURO) according to the severity of upper limb paralysis based on the scores of the Fugl-Meyer assessment for upper extremity (FMA-UE) with recovery in proximal upper extremity, wrist, hand, and coordination.

MATERIALS AND METHODS

In this multicenter retrospective cohort study, the recovery of 1397 patients with upper limb paralysis was analyzed by severity at six hospitals that were accredited by the Japanese Stimulation Therapy Society for treatment. The delta values of the FMA-UE scores before and after NEURO were compared among the groups with severe, moderate, and mild paralysis using the generalized linear model.

RESULTS

NEURO significantly improved the FMA-UE total score according to the severity of paralysis (severe = 5.3, moderate = 6.0, and mild = 2.9). However, when the FMA-UE subscores were analyzed separately, the results indicated specific improvements in shoulder/elbow, wrist, fingers, and coordination movements, depending on the severity.

CONCLUSIONS

This study had enough patients who were divided according to severity and stratified by lesion location and handedness parameters. Our results suggest that independently of these factors, the extent of recovery of upper limb motor parts after NEURO varies according to the severity of paralysis.

A Randomized Controlled Trial of the Effect of Repetitive Transcranial Magnetic Stimulation of the Motor Cortex on Lower Extremity Spasticity in Hereditary Spastic Paraplegia

INTRODUCTION

Hereditary spastic paraplegia refers to a group of conditions characterized by a slow progression of spasticity in lower limbs resulting in gait abnormalities. Current treatment options have proven to be insufficient in terms of symptom alleviation. In this study, we tested the effectiveness of repetitive transcranial magnetic stimulation (rTMS) on lower limb spasticity in patients with hereditary spastic paraplegia.

METHODS

Eight patients were randomly assigned to receive either five sessions of active 5 Hz-rTMS ( n = 4) or sham rTMS ( n = 4). The primary outcome was a change in spasticity assessed by the modified Ashworth scale. Secondary outcomes were change in 10 m walking test, Fugl-Meyer assessment of lower extremity motor function, and quality-of-life short-form survey scores. Assessment of the outcomes was done before, upon completion, and 1 month after the intervention. We analyzed the data using repeated-measure analysis of variance.

RESULTS

Mean age of the participants was 38.5 (SD = 5.4) years, and 50% were women. Compared with sham rTMS, real rTMS was effective in decreasing modified Ashworth scale (rTMS × time: F [df = 2] = 7.44; P = 0.008). Real rTMS group had lower modified Ashworth scale scores at the end of rTMS sessions (estimate = -0.938; SE = 0.295; P = 0.019) and at the end of follow-up (estimate = -0.688; SE = 0.277; P = 0.048) compared with the sham rTMS group. Real and sham rTMS groups were not different in the secondary outcomes.

CONCLUSIONS

Repetitive transcranial magnetic stimulation is an effective method in reducing lower limb spasticity of patients with hereditary spastic paraplegia.

Acupuncture combined with repeated transcranial magnetic stimulation for upper limb motor function after stroke: A systematic review and meta-analysis

BACKGROUND

Upper limb motor dysfunction after stroke is an important factor affecting patients' motor function and daily life. Acupuncture and repetitive transcranial magnetic stimulation are effective methods for stroke rehabilitation. However, a systematic and comprehensive overview of the combined efficacy of the two is lacking.

OBJECTIVE

Through a systematic review and meta-analysis of randomized controlled trials, this study aimed to assess the effectiveness of acupuncture combined with repetitive transcranial magnetic stimulation on upper extremity motor function in post-stroke patients.

METHODS

The relevant randomized controlled trials on acupuncture combined with repetitive transcranial magnetic stimulation in the treatment of upper limb motor disorders after stroke were searched in PubMed, Embase, Cochrane Library, Web of Science CNKI, VIP, Wanfang, and CBM databases. After screening clinical trials that met the inclusion criteria, data extraction was conducted independently by two investigators. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

After the screening, 18 articles were included, with a total of 1083 subjects. The results of meta-analysis showed that combination therapy could effectively improve the patients' upper limb motor function (MD = 7.77, 95%CI [6.32, 9.22], P < 0.05), ability of daily living (MD = 8.53, 95%CI [6.28, 10.79], P < 0.05), and hemiplegic shoulder pain (MD = - 1.72, 95%CI [- 2.26, - 1.18], P < 0.05). Meanwhile, for neurophysiological indexes, combined treatment could significantly shorten the latency of motor evoked potential and central motor conduction time (MD = - 1.42, 95%CI [- 2.14, - 0.71], P < 0.05); (MD = - 0.47, 95%CI [- 0.66, - 0.29], P < 0.05), and also could increase the amplitude of motor evoked potential (SMD = 0.71, 95%CI [0.28, 1.14], P < 0.05).

CONCLUSION

According to the results of the meta-analysis, we can conclude that acupuncture combined with repeated transcranial magnetic stimulation can significantly improve the upper limb motor function and daily living ability of stroke patients.

The effectiveness and safety of repetitive transcranial magnetic stimulation on spasticity after upper motor neuron injury: A systematic review and meta-analysis

To systematically evaluate the effectiveness and safety of repetitive transcranial magnetic stimulation (rTMS) on spasticity after upper motor neuron (UMN) injury. Eight electronic databases were searched from inception to August 6, 2022. Randomized controlled trials (RCTs) investigating the effectiveness and safety of rTMS on spasticity after UMN injury were retrieved. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Review Manager 5.3 and Stata 14.0 software were used to synthesize data. The certainty of the evidence was appraised with the Grade of Recommendation, Assessment, Development and Evaluation tool. Forty-two studies with a total of 2,108 patients were included. The results of meta-analysis revealed that, compared with control group, rTMS could significantly decrease scores of the Modified Ashworth Scale (MAS) in patients with UMN injury. The subgroup analysis discovered that rTMS effectively decreased the MAS scores in patients with stroke. Meanwhile, rTMS treatment > 10 sessions has better effect and rTMS could decrease the MAS scores of upper limb. Thirty-three patients complained of twitching facial muscles, headache and dizziness, etc. In summary, rTMS could be recommended as an effective and safe therapy to relieve spasticity in patients with UMN injury. However, due to high heterogeneity and limited RCTs, this conclusion should be treated with caution.

Effects of repetitive transcranial magnetic stimulation on upper-limb and finger function in stroke patients: A systematic review and meta-analysis of randomized controlled trials

Background

Repetitive transcranial magnetic stimulation (rTMS) is a promising intervention for stroke rehabilitation. Several studies have demonstrated the effectiveness of rTMS in restoring motor function. This meta-analysis aimed to summarize the current evidence of the effect of rTMS in improving upper limb function and fine motor recovery in stroke patients.

Methods

Three online databases (Web of Science, PubMed, and Embase) were searched for relevant randomized controlled trials. A total of 45 studies (combined n = 2064) were included. Random effects model was used for meta-analysis and effect size was reported as standardized mean difference (SMD).

Results

rTMS was effective in improving fine motor function in stroke patients (SMD, 0.38; 95% CI 0.19-0.58; P = 0). On subgroup analyses, for post-stroke functional improvement of the upper extremity, bilateral hemisphere stimulation was more effective than unilateral stimulation during the acute phase of stroke, and a regimen of 20 rTMS sessions produced greater improvement than <20 sessions. In the subacute phase of stroke, affected hemispheric stimulation with a 40-session rTMS regimen was superior to unaffected hemispheric stimulation or bilateral hemispheric stimulation with <40 sessions. Unaffected site stimulation with a 10-session rTMS regimen produced significant improvement in the chronic phase compared to affected side stimulation and bilateral stimulation with >10 rTMS sessions. For the rTMS stimulation method, both TBS and rTMS were found to be significantly more effective in the acute phase of stroke, but TBS was more effective than rTMS. However, rTMS was found to be more effective than TBS stimulation in patients in the subacute and chronic phases of stroke. rTMS significantly improved upper limb and fine function in the short term (0-1-month post-intervention) and medium term (2-5 months), but not for upper limb function in the long term (6 months+). The results should be interpreted with caution due to significant heterogeneity.

Conclusions

This updated meta-analysis provides robust evidence of the efficacy of rTMS treatment in improving upper extremity and fine function during various phases of stroke.

Systematic Review Registration

https://inplasy.com/inplasy-2022-5-0121/, identifier: INPLASY202250121.

Time to reconcile research findings and clinical practice on upper limb neurorehabilitation

The problem

In the field of upper limb neurorehabilitation, the translation from research findings to clinical practice remains troublesome. Patients are not receiving treatments based on the best available evidence. There are certainly multiple reasons to account for this issue, including the power of habit over innovation, subjective beliefs over objective results. We need to take a step forward, by looking at most important results from randomized controlled trials, and then identify key active ingredients that determined the success of interventions. On the other hand, we need to recognize those specific categories of patients having the greatest benefit from each intervention, and why. The aim is to reach the ability to design a neurorehabilitation program based on motor learning principles with established clinical efficacy and tailored for specific patient's needs.

Proposed solutions

The objective of the present manuscript is to facilitate the translation of research findings to clinical practice. Starting from a literature review of selected neurorehabilitation approaches, for each intervention the following elements were highlighted: definition of active ingredients; identification of underlying motor learning principles and neural mechanisms of recovery; inferences from research findings; and recommendations for clinical practice. Furthermore, we included a dedicated chapter on the importance of a comprehensive assessment (objective impairments and patient's perspective) to design personalized and effective neurorehabilitation interventions.

Conclusions

It's time to reconcile research findings with clinical practice. Evidence from literature is consistently showing that neurological patients improve upper limb function, when core strategies based on motor learning principles are applied. To this end, practical take-home messages in the concluding section are provided, focusing on the importance of graded task practice, high number of repetitions, interventions tailored to patient's goals and expectations, solutions to increase and distribute therapy beyond the formal patient-therapist session, and how to integrate different interventions to maximize upper limb motor outcomes. We hope that this manuscript will serve as starting point to fill the gap between theory and practice in upper limb neurorehabilitation, and as a practical tool to leverage the positive impact of clinicians on patients' recovery.

Excitatory Repetitive Transcranial Magnetic Stimulation Over the Ipsilesional Hemisphere for Upper Limb Motor Function After Stroke: A Systematic Review and Meta-Analysis

Background

Repetitive transcranial magnetic stimulation (rTMS) is a promising therapy to promote recovery of the upper limb after stroke. According to the regulation of cortical excitability, rTMS can be divided into excitatory rTMS and inhibitory rTMS, and excitatory rTMS includes high-frequency rTMS (HF-rTMS) or intermittent theta-burst stimulation (iTBS). We aimed to evaluate the effects of excitatory rTMS over the ipsilesional hemisphere on upper limb motor recovery after stroke.

Methods

Databases of PubMed, Embase, ISI Web of Science, and the Cochrane Library were searched for randomized controlled trials published before 31 December 2021. RCTs on the effects of HF-rTMS or iTBS on upper limb function in patients diagnosed with stroke were included. Two researchers independently screened the literature, extracted the data, and assessed quality. The meta-analysis was performed by using Review Manager Version 5.4 software.

Results

Fifteen studies with 449 participants were included in this meta-analysis. This meta-analysis found that excitatory rTMS had significant efficacy on upper limb motor function (MD = 5.88, 95% CI, 3.32–8.43, P < 0.001), hand strength (SMD = 0.53, 95% CI, 0.04–1.01, P = 0.03), and hand dexterity (SMD = 0.76, 95% CI, 0.39–1.14, P < 0.001). Subgroup analyses based on different types of rTMS showed that both iTBS and HF-rTMS significantly promoted upper limb motor function (iTBS, P < 0.001; HF-rTMS, P < 0.001) and hand dexterity (iTBS, P = 0.01; HF-rTMS, P < 0.001) but not hand strength (iTBS, P = 0.07; HF-rTMS, P = 0.12). Further subgroup analysis based on the duration of illness demonstrated that applying excitatory rTMS during the first 3 months (<1 month, P = 0.01; 1–3 months, P = 0.001) after stroke brought significant improvement in upper limb motor function but not in the patients with a duration longer than 3 months (P = 0.06). We found that HF-rTMS significantly enhanced the motor evoked potential (MEP) amplitude of affected hemisphere (SMD = 0.82, 95% CI, 0.32–1.33, P = 0.001).

Conclusion

Our study demonstrated that excitatory rTMS over the ipsilesional hemisphere could significantly improve upper limb motor function, hand strength, and hand dexterity in patients diagnosed with stroke. Both iTBS and HF-rTMS which could significantly promote upper limb motor function and hand dexterity, and excitatory rTMS were beneficial to upper limb motor function recovery only when applied in the first 3 months after stroke. HF-rTMS could significantly enhance the MEP amplitude of the affected hemisphere. High-quality and large-scale randomized controlled trials in the future are required to confirm our conclusions.

Clinical Trial Registration

www.crd.york.ac.uk/prospero/, identifier: CRD42022312288.

Comparative Efficacy of Different Repetitive Transcranial Magnetic Stimulation Protocols for Stroke: A Network Meta-Analysis

Background

Although repetitive transcranial magnetic stimulation (rTMS) has been proven to be effective in the upper limb motor function and activities of daily living (ADL), the therapeutic effects of different stimulation protocols have not been effectively compared. To fill this gap, this study carried out the comparison of the upper limb motor function and ADL performance of patients with stroke through a network meta-analysis.

Methods

Randomized controlled trials (RCTs) on the rTMS therapy for stroke were searched from various databases, including PubMed, web of science, Embase, Cochrane Library, ProQuest, Wanfang database, the China National Knowledge Infrastructure (CNKI), and VIP information (www.cqvip.com). The retrieval period was from the establishment of the database to January 2021. Meanwhile, five independent researchers were responsible for the study selection, data extraction, and quality evaluation. The outcome measures included Upper Extremity Fugl-Meyer Assessment (UE-FMA), Wolf Motor Function Test (WMFT), Modified Barthel Index (MBI), the National Institute of Health stroke scale (NIHSS), and adverse reactions. The Gemtc 0.14.3 software based on the Bayesian model framework was used for network meta-analysis, and funnel plots and network diagram plots were conducted using Stata14.0 software.

Results

Ninety-five studies and 5,016 patients were included ultimately. The intervention measures included were as follows: placebo, intermittent theta-burst stimulation (ITBS), continuous theta-burst stimulation (CTBS),1 Hz rTMS,3–5 Hz rTMS, and ≥10 Hz rTMS. The results of the network meta-analysis show that different rTMS protocols were superior to placebo in terms of UE-FMA, NIHSS, and MBI outcomes. In the probability ranking results, ≥10 Hz rTMS ranked first in UE-FMA, WMFT, and MBI. For the NIHSS outcome, the ITBS ranked first and 1 Hz rTMS ranked the second. The subgroup analyses of UE-FMA showed that ≥10 Hz rTMS was the best stimulation protocol for mild stroke, severe stroke, and the convalescent phase, as well as ITBS was for acute and subacute phases. In addition, it was reported in 13 included studies that only a few patients suffered from adverse reactions, such as headache, nausea, and emesis.

Conclusion

Overall, ≥10 Hz rTMS may be the best stimulation protocol for improving the upper limb motor function and ADL performance in patients with stroke. Considering the impact of stroke severity and phase on the upper limb motor function, ≥10 Hz rTMS may be the preferred stimulation protocol for mild stroke, severe stroke, and for the convalescent phase, and ITBS for acute and subacute phases.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier [CRD42020212253].

Combining Optogenetic Stimulation and Motor Training Improves Functional Recovery and Perilesional Cortical Activity

Background. An ischemic stroke is followed by the remapping of motor representation and extensive changes in cortical excitability involving both hemispheres. Although stimulation of the ipsilesional motor cortex, especially when paired with motor training, facilitates plasticity and functional restoration, the remapping of motor representation of the single and combined treatments is largely unexplored. Objective. We investigated if spatio-temporal features of motor-related cortical activity and the new motor representations are related to the rehabilitative treatment or if they can be specifically associated to functional recovery. Methods. We designed a novel rehabilitative treatment that combines neuro-plasticizing intervention with motor training. In detail, optogenetic stimulation of peri-infarct excitatory neurons expressing Channelrhodopsin 2 was associated with daily motor training on a robotic device. The effectiveness of the combined therapy was compared with spontaneous recovery and with the single treatments (ie optogenetic stimulation or motor training). Results. We found that the extension and localization of the new motor representations are specific to the treatment, where most treatments promote segregation of the motor representation to the peri-infarct region. Interestingly, only the combined therapy promotes both the recovery of forelimb functionality and the rescue of spatio-temporal features of motor-related activity. Functional recovery results from a new excitatory/inhibitory balance between hemispheres as revealed by the augmented motor response flanked by the increased expression of parvalbumin positive neurons in the peri-infarct area. Conclusions. Our findings highlight that functional recovery and restoration of motor-related neuronal activity are not necessarily coupled during post-stroke recovery. Indeed the reestablishment of cortical activation features of calcium transient is distinctive of the most effective therapeutic approach, the combined therapy.

Clinical Effects of Immersive Multimodal BCI-VR Training after Bilateral Neuromodulation with rTMS on Upper Limb Motor Recovery after Stroke. A Study Protocol for a Randomized Controlled Trial

Background and Objectives: The motor sequelae after a stroke are frequently persistent and cause a high degree of disability. Cortical ischemic or hemorrhagic strokes affecting the cortico-spinal pathways are known to cause a reduction of cortical excitability in the lesioned area not only for the local connectivity impairment but also due to a contralateral hemisphere inhibitory action. Non-invasive brain stimulation using high frequency repetitive magnetic transcranial stimulation (rTMS) over the lesioned hemisphere and contralateral cortical inhibition using low-frequency rTMS have been shown to increase the excitability of the lesioned hemisphere. Mental representation techniques, neurofeedback, and virtual reality have also been shown to increase cortical excitability and complement conventional rehabilitation. Materials and Methods: We aim to carry out a single-blind, randomized, controlled trial aiming to study the efficacy of immersive multimodal Brain-Computer Interfacing-Virtual Reality (BCI-VR) training after bilateral neuromodulation with rTMS on upper limb motor recovery after subacute stroke (>3 months) compared to neuromodulation combined with conventional motor imagery tasks. This study will include 42 subjects in a randomized controlled trial design. The main expected outcomes are changes in the Motricity Index of the Arm (MI), dynamometry of the upper limb, score according to Fugl-Meyer for upper limb (FMA-UE), and changes in the Stroke Impact Scale (SIS). The evaluation will be carried out before the intervention, after each intervention and 15 days after the last session. Conclusions: This trial will show the additive value of VR immersive motor imagery as an adjuvant therapy combined with a known effective neuromodulation approach opening new perspectives for clinical rehabilitation protocols.

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.

Navigated repetitive transcranial magnetic stimulation improves the outcome of postsurgical paresis in glioma patients - A randomized, double-blinded trial

BACKGROUND

Navigated repetitive transcranial magnetic stimulation (nrTMS) is effective therapy for stroke patients. Neurorehabilitation could be supported by low-frequency stimulation of the non-damaged hemisphere to reduce transcallosal inhibition.

OBJECTIVE

The present study examines the effect of postoperative nrTMS therapy of the unaffected hemisphere in glioma patients suffering from acute surgery-related paresis of the upper extremity (UE) due to subcortical ischemia.

METHODS

We performed a randomized, sham-controlled, double-blinded trial on patients suffering from acute surgery-related paresis of the UE after glioma resection. Patients were randomly assigned to receive either low frequency nrTMS (1 Hz, 15 min) or sham stimulation directly before physical therapy for 7 consecutive days. We performed primary and secondary outcome measures on day 1, on day 7, and at a 3-month follow-up (FU). The primary endpoint was the change in Fugl-Meyer Assessment (FMA) at FU compared to day 1 after surgery.

RESULTS

Compared to the sham stimulation, nrTMS significantly improved outcomes between day 1 and FU based on the FMA (mean [95% CI] +31.9 [22.6, 41.3] vs. +4.2 [-4.1, 12.5]; P = .001) and the National Institutes of Health Stroke Scale (NIHSS) (-5.6 [-7.5, -3.6] vs. -2.4 [-3.6, -1.2]; P = .02). To achieve a minimal clinically important difference of 10 points on the FMA scale, the number needed to treat is 2.19.

CONCLUSION

The present results show that patients suffering from acute surgery-related paresis of the UE due to subcortical ischemia after glioma resection significantly benefit from low-frequency nrTMS stimulation therapy of the unaffected hemisphere.

CLINICAL TRIAL REGISTRATION

Local institutional registration: 12/15; ClinicalTrials.gov number: NCT03982329.

Discussion on the Rehabilitation of Stroke Hemiplegia Based on Interdisciplinary Combination of Medicine and Engineering

Interdisciplinary combinations of medicine and engineering are part of the strategic plan of many universities aiming to be world-class institutions. One area in which these interactions have been prominent is rehabilitation of stroke hemiplegia. This article reviews advances in the last five years of stroke hemiplegia rehabilitation via interdisciplinary combination of medicine and engineering. Examples of these technologies include VR, RT, mHealth, BCI, tDCS, rTMS, and TCM rehabilitation. In this article, we will summarize the latest research in these areas and discuss the advantages and disadvantages of each to examine the frontiers of interdisciplinary medicine and engineering advances.

Efficacy of coupling intermittent theta-burst stimulation and 1 Hz repetitive transcranial magnetic stimulation to enhance upper limb motor recovery in subacute stroke patients: A randomized controlled trial

BACKGROUND

Both 1 Hz repetitive transcranial magnetic stimulation (rTMS) and intermittent theta-burst stimulation (iTBS) are reported to benefit upper limb motor function rehabilitation in patients with stroke. However, the efficacy of combining 1 Hz rTMS and iTBS has not been adequately explored.

OBJECTIVE

We aimed to compare the effects of 1 Hz rTMS and the combination of 1 Hz rTMS and iTBS on the upper limb motor function in the subacute phase post-stroke.

METHODS

Twenty-eight participants were randomly assigned to three groups: Group A (1 Hz rTMS over the contralesional primary motor cortex (M1) and iTBS over the ipsilesional M1), Group B (contralesional 1 Hz rTMS and ipsilesional sham iTBS), and Group C (contralesional sham 1 Hz rTMS and ipsilesional sham iTBS). The participants received the same conventional rehabilitation accompanied by sessions of transcranial magnetic stimulation for two weeks (5 days one week). Motor-evoked potential (MEP), upper extremity Fugl-Meyer Assessment (UE-FMA), and Barthel Index (BI) were performed before and after the sessions.

RESULTS

Group A showed greater UE-FMA, BI, and MEP amplitude improvement and more significant decrement in MEP latency compared to Group B and Group C in testable patients. Correlation analyses in Group A revealed a close relation between ipsilesional MEP amplitude increment and UE-FMA gain.

CONCLUSIONS

The combining of 1 Hz rTMS and iTBS protocol in the present study is tolerable and more beneficial for motor improvement than the single use of 1 Hz rTMS in patients with subacute stroke.

Canadian Platform for Trials in Noninvasive Brain Stimulation (CanStim) Consensus Recommendations for Repetitive Transcranial Magnetic Stimulation in Upper Extremity Motor Stroke Rehabilitation Trials

Objective. To develop consensus recommendations for the use of repetitive transcranial magnetic stimulation (rTMS) as an adjunct intervention for upper extremity motor recovery in stroke rehabilitation clinical trials. Participants. The Canadian Platform for Trials in Non-Invasive Brain Stimulation (CanStim) convened a multidisciplinary team of clinicians and researchers from institutions across Canada to form the CanStim Consensus Expert Working Group. Consensus Process. Four consensus themes were identified: (1) patient population, (2) rehabilitation interventions, (3) outcome measures, and (4) stimulation parameters. Theme leaders conducted comprehensive evidence reviews for each theme, and during a 2-day Consensus Meeting, the Expert Working Group used a weighted dot-voting consensus procedure to achieve consensus on recommendations for the use of rTMS as an adjunct intervention in motor stroke recovery rehabilitation clinical trials. Results. Based on best available evidence, consensus was achieved for recommendations identifying the target poststroke population, rehabilitation intervention, objective and subjective outcomes, and specific rTMS parameters for rehabilitation trials evaluating the efficacy of rTMS as an adjunct therapy for upper extremity motor stroke recovery. Conclusions. The establishment of the CanStim platform and development of these consensus recommendations is a first step toward the translation of noninvasive brain stimulation technologies from the laboratory to clinic to enhance stroke recovery.

Excess Significance Bias in Repetitive Transcranial Magnetic Stimulation Literature for Neuropsychiatric Disorders

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) has been widely tested and promoted for use in multiple neuropsychiatric conditions, but as for many other medical devices, some gaps may exist in the literature and the evidence base for the clinical efficacy of rTMS remains under debate.

OBJECTIVE

We aimed to test for an excess number of statistically significant results in the literature on the therapeutic efficacy of rTMS across a wide range of meta-analyses and to characterize the power of studies included in these meta-analyses.

METHODS

Based on power calculations, we computed the expected number of "positive" datasets for a medium effect size (standardized mean difference, SMD = 0.30) and compared it with the number of observed "positive" datasets. Sensitivity analyses considered small (SMD = 0.20), modest (SMD = 0.50), and large (SMD = 0.80) effect sizes.

RESULTS

A total of 14 meta-analyses with 228 datasets (110 for neurological disorders and 118 for psychiatric disorders) were assessed. For SMD = 0.3, the number of observed "positive" studies (n = 94) was larger than expected (n = 35). We found evidence for an excess of significant findings overall (p < 0.0001) and in 8/14 meta-analyses. Evidence for an excess of significant findings was also observed for SMD = 0.5 for neurological disorders. Of the 228 datasets, 0 (0%), 0 (0%), 3 (1%), and 53 (23%) had a power >0.80, respectively, for SMDs of 0.30, 0.20, 0.50, and 0.80.

CONCLUSION

Most studies in the rTMS literature are underpowered. This results in fragmentation and waste of research efforts. The somewhat high frequency of "positive" results seems spurious and may reflect bias. Caution is warranted in accepting rTMS as an established treatment for neuropsychiatric conditions.

Neurostimulation and Reach-to-Grasp Function Recovery Following Acquired Brain Injury: Insight From Pre-clinical Rodent Models and Human Applications

Reach-to-grasp is an evolutionarily conserved motor function that is adversely impacted following stroke and traumatic brain injury (TBI). Non-invasive brain stimulation (NIBS) methods, such as transcranial magnetic stimulation and transcranial direct current stimulation, are promising tools that could enhance functional recovery of reach-to-grasp post-brain injury. Though the rodent literature provides a causal understanding of post-injury recovery mechanisms, it has had a limited impact on NIBS protocols in human research. The high degree of homology in reach-to-grasp circuitry between humans and rodents further implies that the application of NIBS to brain injury could be better informed by findings from pre-clinical rodent models and neurorehabilitation research. Here, we provide an overview of the advantages and limitations of using rodent models to advance our current understanding of human reach-to-grasp function, cortical circuitry, and reorganization. We propose that a cross-species comparison of reach-to-grasp recovery could provide a mechanistic framework for clinically efficacious NIBS treatments that could elicit better functional outcomes for patients.

Timing of Repetitive Transcranial Magnetic Stimulation Onset for Upper Limb Function After Stroke: A Systematic Review and Meta-Analysis

Background: Repetitive transcranial magnetic stimulation (rTMS) is a promising intervention to promote upper limb recovery after stroke. We aimed to identify differences in the efficacy of rTMS treatment on upper limb function depending on the onset time post-stroke.

Methods: We searched PubMed, Embase, and the Cochrane Library to identify relevant RCTs from their inception to February 2018. RCTs on the effects of rTMS on upper limb function in adult patients with stroke were included. Study quality and risk of bias were assessed independently by two authors. Meta-analyses were performed for outcomes on individual upper limb outcome measures (function or activity) and for function and activity measures jointly, categorized by timing of treatment initiation. Timing of treatment initiation post-stroke was categorized as follows: acute to early subacute (<1 month), early subacute (1–3 months), late subacute (3–6 months), and chronic (>6 months).

Results: We included 38 studies involving 1,074 stroke patients. Subgroup analysis demonstrated benefit of rTMS applied within the first month post-stroke [MD = 9.31; 95% confidence interval (6.27–12.34); P < 0.0001], but not in the early subacute phase (1–3 months post-stroke) [MD = 1.14; 95% confidence interval (−5.32 to 7.59), P = 0.73) or chronic phase (>6 months post-stroke) [MD = 1.79; 95% confidence interval (−2.00 to 5.59]; P = 0.35), when assessed with a function test [Fugl-Meyer Arm test (FMA)]. There were no studies within the late subacute phase (3–6 months post-stroke) that used the FMA. Tests at the level of function revealed improved upper limb function after rTMS [SMD = 0.43; 95% confidence interval (0.02–0.75); P = 0.0001], but tests at the level of activity did not, independent of rTMS onset post-stroke [SMD = 0.17; 95% confidence interval (−0.09 to 0.44); P = 0.19]. Heterogeneities in the results of the individual studies included in the main analyses were large, as suggested by funnel plot asymmetry.

Conclusions: Based on the FMA, rTMS seems more beneficial only when started in the first month post-stroke. Tests at the level of function are likely more sensitive to detect beneficial rTMS effects on upper limb function than tests at the level of activity. However, heterogeneities in treatment designs and outcomes are high. Future rTMS trials should include the FMA and work toward a core set of outcome measures.

Low-Frequency Brain Oscillations Track Motor Recovery in Human Stroke

OBJECTIVE

The majority of patients with stroke survive the acute episode and live with enduring disability. Effective therapies to support recovery of motor function after stroke are yet to be developed. Key to this development is the identification of neurophysiologic signals that mark recovery and are suitable and susceptible to interventional therapies. Movement preparatory low-frequency oscillations (LFOs) play a key role in cortical control of movement. Recent animal data point to a mechanistic role of motor cortical LFOs in stroke motor deficits and demonstrate neuromodulation intervention with therapeutic benefit. Their relevance in human stroke pathophysiology is unknown.

METHODS

We studied the relationship between movement-preparatory LFOs during the performance of a visuomotor grip task and motor function in a longitudinal (<5 days, 1 and 3 months) cohort study of 33 patients with motor stroke and in 19 healthy volunteers.

RESULTS

Acute stroke-lesioned brains fail to generate the LFO signal. Whereas in healthy humans, a transient occurrence of LFOs preceded movement onset at predominantly contralateral frontoparietal motor regions, recordings in patients revealed that movement-preparatory LFOs were substantially diminished to a level of 38% after acute stroke. LFOs progressively increased at 1 and 3 months. This re-emergence closely tracked the recovery of motor function across several movement qualities including grip strength, fine motor skills, and synergies and was frequency band specific.

INTERPRETATION

Our results provide the first human evidence for a link between movement-preparatory LFOs and functional recovery after stroke, promoting their relevance for movement control. These results suggest that it may be interesting to explore targeted, LFOs-restorative brain stimulation therapy in human stroke patients. ANN NEUROL 2019;86:853-865.

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.

Effectiveness of interventions to improve hand motor function in individuals with moderate to severe stroke: a systematic review protocol

INTRODUCTION

The human hand is extremely involved in our daily lives. However, the rehabilitation of hand function after stroke can be rather difficult due to the complexity of hand structure and function, as well as neural basis that supports hand function. Specifically, in individuals with moderate to severe impairment following a stroke, previous evidence for effective treatments that recover hand function in this population is limited, and thus has never been reviewed. With the progress of rehabilitation science and tool development, results from more and more clinical trials are now available, thereby justifying conducting a systematic review.

METHODS AND ANALYSIS

This systematic review protocol is consistent with the methodology recommended by the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the Cochrane handbook for systematic reviews of interventions. Electronic searches will be carried out in the PubMed, CINAHL, Physiotherapy Evidence Database and Cochrane Library databases, along with manual searches in the reference lists from included studies and published systematic reviews. The date range parameters used in searching all databases is between January 1999 and January 2019. Randomised controlled trials (RCTs) published in English, with the primary outcome focusing on hand motor function, will be included. Two reviewers will screen all retrieved titles, abstracts and full texts, perform the evaluation of the risk bias and extract all data independently. The risk of bias of the included RCTs will be evaluated by the Cochrane Collaboration's tool. A qualitative synthesis will be provided in text and table, to summarise the main results of the selected publications. A meta-analysis will be considered if there is sufficient homogeneity across outcomes. The quality of the included publications will be evaluated by the Grading of Recommendations Assessment, Development and Evaluation system from the Cochrane Handbook for Systematic Reviews of Interventions.

ETHICS AND DISSEMINATION

No ethical approval is needed, and the results of this review will be disseminated via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

CRD42019128285.

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.

Intermittent theta burst stimulation enhances upper limb motor function in patients with chronic stroke: a pilot randomized controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) is a form of repetitive transcranial stimulation that has been used to enhance upper limb (UL) motor recovery. However, only limited studies have examined its efficacy in patients with chronic stroke and therefore it remains controversial.

METHODS

This was a randomized controlled trial that enrolled patients from a rehabilitation department. Twenty-two patients with first-ever chronic and unilateral cerebral stroke, aged 30-70 years, were randomly assigned to the iTBS or control group. All patients received 1 session per day for 10 days of either iTBS or sham stimulation over the ipsilesional primary motor cortex in addition to conventional neurorehabilitation. Outcome measures were assessed before and immediately after the intervention period: Modified Ashworth Scale (MAS), Fugl-Meyer Assessment Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), Box and Block test (BBT), and Motor Activity Log (MAL). Analysis of covariance was adopted to compare the treatment effects between groups.

RESULTS

The iTBS group had greater improvement in the MAS and FMA than the control group (η² = 0.151-0.233; p < 0.05), as well as in the ARAT and BBT (η² = 0.161-0.460; p < 0.05) with large effect size. Both groups showed an improvement in the BBT, and there were no significant between-group differences in MAL changes.

CONCLUSIONS

The iTBS induced greater gains in spasticity decrease and UL function improvement, especially in fine motor function, than sham TBS. This is a promising finding because patients with chronic stroke have a relatively low potential for fine motor function recovery. Overall, iTBS may be a beneficial adjunct therapy to neurorehabilitation for enhancing UL function. Further larger-scale study is warranted to confirm the findings and its long-term effect.

TRIAL REGISTRATION

This trial was registered under ClinicalTrials.gov ID No. NCT01947413 on September 20, 2013.

Rethinking interhemispheric imbalance as a target for stroke neurorehabilitation

OBJECTIVE

Patients with chronic stroke have been shown to have failure to release interhemispheric inhibition (IHI) from the intact to the damaged hemisphere before movement execution (premovement IHI). This inhibitory imbalance was found to correlate with poor motor performance in the chronic stage after stroke and has since become a target for therapeutic interventions. The logic of this approach, however, implies that abnormal premovement IHI is causal to poor behavioral outcome and should therefore be present early after stroke when motor impairment is at its worst. To test this idea, in a longitudinal study, we investigated interhemispheric interactions by tracking patients' premovement IHI for one year following stroke.

METHODS

We assessed premovement IHI and motor behavior five times over a 1-year period after ischemic stroke in 22 patients and 11 healthy participants.

RESULTS

We found that premovement IHI was normal during the acute/subacute period and only became abnormal at the chronic stage; specifically, release of IHI in movement preparation worsened as motor behavior improved. In addition, premovement IHI did not correlate with behavioral measures cross-sectionally, whereas the longitudinal emergence of abnormal premovement IHI from the acute to the chronic stage was inversely correlated with recovery of finger individuation.

INTERPRETATION

These results suggest that interhemispheric imbalance is not a cause of poor motor recovery, but instead might be the consequence of underlying recovery processes. These findings call into question the rehabilitation strategy of attempting to rebalance interhemispheric interactions in order to improve motor recovery after stroke. Ann Neurol 2019;85:502-513.

The effect and optimal parameters of repetitive transcranial magnetic stimulation on motor recovery in stroke patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The primary aim of this meta-analysis was to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on limb movement recovery post-stroke and cortex excitability, to explore the optimal parameters of rTMS and suitable stroke population. Second, adverse events were also included.

DATA SOURCES

The databases of PubMed, EBSCO, MEDLINE, the Cochrane Central Register of Controlled Trials, EBM Reviews-Cochrane Database, the Chinese National Knowledge Infrastructure, and the Chinese Science and Technology Journals Database were searched for randomized controlled trials exploring the effects of rTMS on limb motor function recovery post-stroke before December 2018.

REVIEW METHODS

The effect sizes of rTMS on limb motor recovery, the effect size of rTMS stimulation parameters, and different stroke population were summarized by calculating the standardized mean difference (SMD) and the 95% confidence interval using fixed/random effect models as appropriate.

RESULTS

For the motor function assessment, 42 eligible studies involving 1168 stroke patients were identified. The summary effect size indicated that rTMS had positive effects on limb motor recovery (SMD = 0.50, P < 0.00001) and activities of daily living (SMD = 0.82, P < 0.00001), and motor-evoked potentials of the stimulated hemisphere differed according to the stimulation frequency, that is, the high-frequency group (SMD = 0.57, P = 0.0006), except the low-frequency group (SMD = -0.27, P = 0.05). No significant differences were observed among the stimulation parameter subgroups except for the sessions subgroup ( P = 0.02). Only 10 included articles reported transient mild discomfort after rTMS.

CONCLUSIONS

rTMS promoted the recovery of limb motor function and changed the cortex excitability. rTMS may be better for early and pure subcortical stroke patients. Regarding different stimulation parameters, the number of stimulation sessions has an impact on the effect of rTMS.

Noninvasive brain stimulation combined with other therapies improves gait speed after stroke: a systematic review and meta-analysis

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are noninvasive brain stimulation (NIBS) techniques able to modulate cortical excitability.

OBJECTIVE

To determine the effects of NIBS combined with other therapies on gait speed after stroke.

METHODS

Electronic databases searched were PUBMED, EMBASE, COCHRANE, SCOPUS, SCIELO and PEDro. Eligibility criteria were randomized controlled trials that reported the effects of tDCS and rTMS combined with other therapies for improving gait speed, walking cadence, functional ambulation category (FAC) and motricity index (MI-LE) after stroke. Risk of bias was assessed by Cochrane risk of bias assessment tool. Mean differences (MD) and 95% confidence intervals were calculated. Quality of evidence was assessed by Grades of Researches, Assessment, Development and Evaluation approach.

RESULTS

Ten studies (226 subjects) were included in the meta-analysis. NIBS combined with other therapies was effective for improving gait speed (MD 0.09 m/s [95% CI, 0.05 to 0.13; I² 0%, p < 0.0001]). Gait speed improved in both acute/subacute (MD 0.08 m/s [95% CI, 0.02 to 0.14]) and chronic phases (MD 0.08 m/s [95% CI, 0.03 to 0.13]). Furthermore, inhibitory (MD 0.09 m/s [95% CI, 0.04 to 0.14]) and excitatory (MD 0.07 m/s [95% CI, 0.02 to 0.12]) protocols were effective to improve gait speed. NIBS was also effective to improve walking cadence but was unable to modify other outcomes (FAC and MI-LE).

CONCLUSIONS

This systematic review with meta-analysis synthesizes moderate-quality evidence that NIBS combined with other therapies are effective to improve gait speed after stroke. Systematic Review registration number: PROSPERO registration number CDR42015024237.

Transcranial magnetic stimulation and environmental enrichment enhances cortical excitability and functional outcomes after traumatic brain injury

BACKGROUND

Therapeutic strategies for traumatic brain injury (TBI) in the last three decades have failed to show significant benefit in large scale studies. Given the multitude of pathological mechanisms involved in TBI, strategies focusing on multimodality regimen have gained interest as promising future interventions.

HYPOTHESIS

We hypothesized that combining noninvasive transcranial magnetic stimulation (TMS) with rehabilitative training in an environmental enrichment (EE) can facilitate post-TBI recovery in rats via cortical excitability and reorganization.

METHODS

We subjected rats to controlled cortical impact, and then assigned them to one of four groups: 1. No treatments (TBI), 2. EE after injury (TBI + EE), 3. TMS for one week (TBI + TMS), and 4. TMS for one week combined with EE (TBI + TMS/EE). For TMS, a 10 Hz repetitive TMS protocol was used.

RESULTS

At 7 days, TBI + TMS and TBI + TMS/EE groups had significantly increased primary somatosensory cortex local field potential (LFP) compared to TBI and TBI + EE groups (P < 0.05). Also, TBI + TMS/EE group had significantly improved performance on beam walk test compared to TBI group (P < 0.005). At 6 weeks, there was significantly higher response in TBI + TMS/EE group compared to TBI + TMS for somatosensory cortex LFP (P < 0.05), bicep motor evoked potentials (MEP) (P < 0.05), challenge ladder test performance (P < 0.01), and fMRI responses to tactile forepaw stimulation.

CONCLUSIONS

We demonstrate here for the first time the mechanism by which combined therapy using TMS and EE after TBI leads to functional improvement, possibly via cortical excitability and reorganization.

Video evidence of improved hand function following repetitive transcranial magnetic stimulation combined with physical therapy in stroke: a case report

In a 46‐year‐old female 6 months poststroke who presented with minimal paretic hand function, repetitive transcranial magnetic stimulation (rTMS), and exercises considerably improved her function beyond that accomplished with conventional rehabilitation. However, intermittent rTMS (2 sessions/week) was required to sustain the benefits. Research is required to determine the critical frequency of intermittent rTMS needed to sustain functional gains long term.

Low-frequency rTMS of the unaffected hemisphere in stroke patients: A systematic review

The aim of this review was to summarize the evidence for the effectiveness of low-frequency (LF) repetitive transcranial magnetic stimulation (rTMS) over the unaffected hemisphere in promoting functional recovery after stroke. We performed a systematic search of the studies using LF-rTMS over the contralesional hemisphere in stroke patients and reviewed the 67 identified articles. The studies have been gathered together according to the time interval that had elapsed between the stroke onset and the beginning of the rTMS treatment. Inhibitory rTMS of the contralesional hemisphere can induce beneficial effects on stroke patients with motor impairment, spasticity, aphasia, hemispatial neglect and dysphagia, but the therapeutic clinical significance is unclear. We observed considerable heterogeneity across studies in the stimulation protocols. The use of different patient populations, regardless of lesion site and stroke aetiology, different stimulation parameters and outcome measures means that the studies are not readily comparable, and estimating real effectiveness or reproducibility is very difficult. It seems that careful experimental design is needed and it should consider patient selection aspects, rTMS parameters and clinical assessment tools. Consecutive sessions of rTMS, as well as the combination with conventional rehabilitation therapy, may increase the magnitude and duration of the beneficial effects. In an increasing number of studies, the patients have been enrolled early after stroke. The prolonged follow-up in these patients suggests that the effects of contralesional LF-rTMS can be long-lasting. However, physiological evidence indicating increased synaptic plasticity, and thus, a more favourable outcome, in the early enrolled patients, is still lacking. Carefully designed clinical trials designed are required to address this question. LF rTMS over unaffected hemisphere may have therapeutic utility, but the evidence is still preliminary and the findings need to be confirmed in further randomized controlled trials.

Visual feedback alters force control and functional activity in the visuomotor network after stroke

Modulating visual feedback may be a viable option to improve motor function after stroke, but the neurophysiological basis for this improvement is not clear. Visual gain can be manipulated by increasing or decreasing the spatial amplitude of an error signal. Here, we combined a unilateral visually guided grip force task with functional MRI to understand how changes in the gain of visual feedback alter brain activity in the chronic phase after stroke. Analyses focused on brain activation when force was produced by the most impaired hand of the stroke group as compared to the non-dominant hand of the control group. Our experiment produced three novel results. First, gain-related improvements in force control were associated with an increase in activity in many regions within the visuomotor network in both the stroke and control groups. These regions include the extrastriate visual cortex, inferior parietal lobule, ventral premotor cortex, cerebellum, and supplementary motor area. Second, the stroke group showed gain-related increases in activity in additional regions of lobules VI and VIIb of the ipsilateral cerebellum. Third, relative to the control group, the stroke group showed increased activity in the ipsilateral primary motor cortex, and activity in this region did not vary as a function of visual feedback gain. The visuomotor network, cerebellum, and ipsilateral primary motor cortex have each been targeted in rehabilitation interventions after stroke. Our observations provide new insight into the role these regions play in processing visual gain during a precisely controlled visuomotor task in the chronic phase after stroke.

Restoring Motor Functions After Stroke: Multiple Approaches and Opportunities

More than 1.5 million people suffer a stroke in Europe per year and more than 70% of stroke survivors experience limited functional recovery of their upper limb, resulting in diminished quality of life. Therefore, interventions to address upper-limb impairment are a priority for stroke survivors and clinicians. While a significant body of evidence supports the use of conventional treatments, such as intensive motor training or constraint-induced movement therapy, the limited and heterogeneous improvements they allow are, for most patients, usually not sufficient to return to full autonomy. Various innovative neurorehabilitation strategies are emerging in order to enhance beneficial plasticity and improve motor recovery. Among them, robotic technologies, brain-computer interfaces, or noninvasive brain stimulation (NIBS) are showing encouraging results. These innovative interventions, such as NIBS, will only provide maximized effects, if the field moves away from the “one-fits all” approach toward a “patient-tailored” approach. After summarizing the most commonly used rehabilitation approaches, we will focus on NIBS and highlight the factors that limit its widespread use in clinical settings. Subsequently, we will propose potential biomarkers that might help to stratify stroke patients in order to identify the individualized optimal therapy. We will discuss future methodological developments, which could open new avenues for poststroke rehabilitation, toward more patient-tailored precision medicine approaches and pathophysiologically motivated strategies.

Combined Brain and Peripheral Nerve Stimulation in Chronic Stroke Patients With Moderate to Severe Motor Impairment

OBJECTIVES

To evaluate effects of somatosensory stimulation in the form of repetitive peripheral nerve sensory stimulation (RPSS) in combination with transcranial direct current stimulation (tDCS), tDCS alone, RPSS alone, or sham RPSS + tDCS as add-on interventions to training of wrist extension with functional electrical stimulation (FES), in chronic stroke patients with moderate to severe upper limb impairments in a crossover design. We hypothesized that the combination of RPSS and tDCS would enhance the effects of FES on active range of movement (ROM) of the paretic wrist to a greater extent than RPSS alone, tDCS alone or sham RPSS + tDCS.

MATERIALS AND METHODS

The primary outcome was the active ROM of extension of the paretic wrist. Secondary outcomes were ROM of wrist flexion, grasp, and pinch strength of the paretic and nonparetic upper limbs, and ROM of wrist extension of the nonparetic wrist. Outcomes were blindly evaluated before and after each intervention. Analysis of variance with repeated measures with factors "session" and "time" was performed.

RESULTS

After screening 2499 subjects, 22 were included. Data from 20 subjects were analyzed. There were significant effects of "time" for grasp force of the paretic limb and for ROM of wrist extension of the nonparetic limb, but no effects of "session" or interaction "session x time." There were no significant effects of "session," "time," or interaction "session x time" regarding other outcomes.

CONCLUSIONS

Single sessions of PSS + tDCS, tDCS alone, or RPSS alone did not improve training effects in chronic stroke patients with moderate to severe impairment.

Combining Upper Limb Robotic Rehabilitation with Other Therapeutic Approaches after Stroke: Current Status, Rationale, and Challenges

A better understanding of the neural substrates that underlie motor recovery after stroke has led to the development of innovative rehabilitation strategies and tools that incorporate key elements of motor skill relearning, that is, intensive motor training involving goal-oriented repeated movements. Robotic devices for the upper limb are increasingly used in rehabilitation. Studies have demonstrated the effectiveness of these devices in reducing motor impairments, but less so for the improvement of upper limb function. Other studies have begun to investigate the benefits of combined approaches that target muscle function (functional electrical stimulation and botulinum toxin injections), modulate neural activity (noninvasive brain stimulation), and enhance motivation (virtual reality) in an attempt to potentialize the benefits of robot-mediated training. The aim of this paper is to overview the current status of such combined treatments and to analyze the rationale behind them.